Category Archives: Science News

Evolution Of An Imprinted Domain In Mammals:

The normal human genome contains 46 chromosomes: 23 from the mother and 23 from the father. Thus, you have two copies of every gene (excluding some irregularity in the pair of sex chromosomes). In general, which parent contributes a chromosome has no effect on the expression of the genes found on it. Exceptions to this rule are caused by “genomic imprinting”–modification of DNA, which means that gene expression is influenced by which parent the gene came from. A new paper investigates the evolution of genomic imprinting in a specific region of the mammalian genome. The work, by Anne Ferguson-Smith and colleagues in the UK and Australia, shows that different regions became imprinted at different times during mammalian evolution.

Sad Children Out-perform Happy Children In Attention-to-detail Tasks:

Psychologists at the University of Virginia and the University of Plymouth (United Kingdom) have conducted experimental research that contrasts with the belief that happy children are the best learners. The findings show that where attention to detail is required, happy children may be at a disadvantage.

Bilateral Cochlear Implants: A Case When Two Are Definitely Superior To One:

A study of cochlear implant patients seen by Indiana University School of Medicine physicians is the first research to show evidence that cochlear implants in both ears significantly improves quality of life in patients with profound hearing loss and that the cost of the second implant is offset by its benefits.

Bikini-clad Women Make Men Impatient:

Images of sexy women tend to whet men’s sexual appetite. But stimulating new research in the Journal of Consumer Research says there’s more than meets the eye. A recent study shows that men who watched sexy videos or handled lingerie sought immediate gratification–even when they were making decisions about money, soda, and candy.

Strong Evidence For A Genetic Marker For Nearsightedness:

Research by Gu Zhu, M.D., and colleagues supports the theory that the refractive errors known as nearsightedness and farsightedness are primarily inherited. The group also identified the probable location—on the long arm of chromosome 5—of genes that help determine axial length, a key factor in these refractive errors. Axial length is a specific measurement from the front to back of the eye; this distance is longer than normal when a person is nearsighted and shorter than normal in a farsighted person.

Reforestation Using Exotic Plants Can Disturb Fertility Of Tropical Soils:

In many regions of the world, the impact of human activity on the environment intensified considerably over the past century. The high world population growth rate and the expansion of areas given over to crop production associated with climatic changes (longer periods of drought, irregular rainfall patterns) induced by global warming, have contributed to the acceleration of desertification.

The ‘Other’ Neglected Diseases in Global Public Health: Surgical Conditions in Sub-Saharan Africa:

Currently in sub-Saharan Africa, most patients with surgical problems that are routinely treatable in high-income countries never reach a health facility, or are treated at a facility with inadequate human or physical resources. These conditions lead to premature death or physical disability with a significant economic burden. Meanwhile, the last decade has seen the emergence of numerous “neglected tropical disease” (NTD) initiatives in global public health. As surgeons working with clinicians in sub-Saharan Africa, the momentum for NTDs causes us to ask: Shouldn’t surgical conditions also be considered “neglected”?
This article compares NTDs and surgical conditions in sub-Saharan Africa, considering their estimated burden and the cost-effectiveness of treatment, the scope of these conditions and associated global health disparities, and the effect of donor priorities on provision of surgical services. Lessons from NTD initiatives are analyzed among possible solutions to improving access to surgical services in sub-Saharan Africa.

The Ticket to Transport:

Cell nuclei are like gated communities–quite selective about who gets in. And understandably so, because if the wrong proteins showed up at the wrong time and place, the consequences could be disastrous. The standard procedure for moving large molecules that cannot diffuse from the cytoplasm into the nucleus is to use the transport proteins known as karyopherins as escorts. How do karyopherins know whether their cargo is a protein that ought to get in? By their ability to bind with recognition sites on the cargo: no recognition, no passage. The best known example is the canonical or classical nuclear localization signal (cNLS)–a specific sequence that, when added to a protein, drives its nuclear localization. But more recently, a new class of NLSs has been identified, known as a proline-tyrosine nuclear localization signal (PY-NLS). This new signal is recognized specifically by the highly conserved transporter molecule Karyopherinβ2.

Feasibility Of Preventing Malaria Parasite From Becoming Sexually Mature Demonstrated:

Researchers have demonstrated the possibility of preventing the human malaria parasite, Plasmodium falciparum, which is responsible for more than a million malaria deaths a year, from becoming sexually mature.

New Barn Swallow Study Reveals Image Makes The Bird:

In the world of birds, where fancy can be as fleeting as flight, the color of the bird apparently has a profound effect on more than just its image. A new study of barn swallows reveals it also affects the bird’s physiology.

Toad Research Could Leapfrog To New Muscle Model:

A toad sits at a pond’s edge eyeing a cricket on a blade of grass. In the blink of an eye, the toad snares the insect with its tongue. This deceptively simple, remarkably fast feeding action offers a new look at how muscles work.

Kew Gardens Provides Climate For Agricultural Change:

A device to help some of the most impoverished farmers in Africa maximise their crop yields is being tested at London’s Kew Gardens.

Factors That Make Bacteria More Modular Detailed:

Many bacteria break their metabolic processes into chunks. That may be logically tidy, but it’s often metabolically inefficient. Researchers have now figured out the factors that tend to make bacteria more modular.

A Great Lakes Mystery: The Case Of The Disappearing Species:

Throughout the overlooked depths of Lake Michigan and other Great Lakes, a small but important animal is rapidly disappearing.

Living Fossils Have Long- And Short-term Memory Despite Lacking Brain Structures Of Modern Cephalopods:

Robyn Crook from the City University of New York reports that Nautilus, the ancient living ancestors of modern cephalopods, have both long and short-term memory, despite lacking the brain structures that modern cephalopods evolved for long-term memory.

Slide Rule Sense: Amazonian Indigenous Culture Demonstrates Universal Mapping Of Number Onto Space:

The ability to map numbers onto a line, a foundation of all mathematics, is universal, says a study published May 30 in the journal Science, but the form of this universal mapping is not linear but logarithmic. The findings illuminate both the nature and the limits of the human predisposition to measurement, a foundation for science, engineering, and much of our modern culture.

Scientists Discover Stinging Truths About Jellyfish Blooms In The Bering Sea:

A new study helps explain a cyclic increase and decrease of jellyfish populations, which transformed parts of the Bering Sea–one of the U.S.’s most productive fisheries–into veritable jellytoriums during the 1990s.

How People Influence Connectivity Among Ecosystems:

Ecosystems are constantly exchanging materials through the movement of air in the atmosphere, the flow of water in rivers and the migration of animals across the landscape. People, however, have also established themselves as another major driver of connectivity among ecosystems.

Taxonomists Describe The Top 10 Most Surprising Species Discovered In 2007:

Each year the scientific community identifies around 17,000 new animals and plants. To attract people’s attention on the discovery of species, a key for their evolution, survival and conservation, an international committee of experts has just published a list of the 10 most curious and surprising species described in 2007.

How To Construct A ‘Firefly’ Worm:

Research describing a new modified luminescent worm allows, for the first time, one to measure, in real time, the metabolism of an entire living organism. The key behind this capacity relies in the fact that the luminescence is produced using the animal’s available energy, which reflects its metabolism that, as such, can be extrapolated from measuring the emitted light.

Healthy Parents Provide Clues To Survival Of Young Haddock On Georges Bank:

In 2003, haddock on Georges Bank experienced the largest baby boom ever documented for the stock, with an estimated 800 million new young fish entering the population. With typical annual averages of 50 to 100 million new fish in the last few decades, fisheries biologists have been puzzled by the huge increase and its ramifications for stock management. They have been looking for answers and may have found one – healthy adults.

Why Are Computational Neuroscience and Systems Biology So Separate?:

Despite similar computational approaches, there is surprisingly little interaction between the computational neuroscience and the systems biology research communities. In this review I reconstruct the history of the two disciplines and show that this may explain why they grew up apart. The separation is a pity, as both fields can learn quite a bit from each other. Several examples are given, covering sociological, software technical, and methodological aspects. Systems biology is a better organized community which is very effective at sharing resources, while computational neuroscience has more experience in multiscale modeling and the analysis of information processing by biological systems. Finally, I speculate about how the relationship between the two fields may evolve in the near future.

Hmmm, perhaps in some areas of biology, but I saw a great exception (there are two other exceptions noted in the first comment on the paper as well).
Ten Simple Rules for Aspiring Scientists in a Low-Income Country:

Being a scientist entails a common set of characteristics. Admiring nature and having concern for social issues; possessing a strong academic background, team work abilities, honesty, discipline, skepticism, communication skills, competitiveness, ability to accept and give criticism, and productive relationships are some of the most obvious traits that scientists should have. To be a scientist in a low-income country (LIC), however, requires a complementary set of qualities that are necessary to confront the drawbacks that work against the development of science. The failure of many young researchers to mature as professional scientists upon their return to their country from advanced training elsewhere, motivated us to propose these ten rules.

This is something I’ll forwards to my scientist friends in Belgrade….

U.S. Reporters Often Do A Poor Job Of Reporting About New Medical Treatments, Analysis Finds:

Most medical news stories about health interventions fail to adequately address costs, harms, benefits, the quality of evidence, and the existence of other treatment options, finds a new analysis in this week’s PLoS Medicine. The analysis was conducted by Gary Schwitzer from the University of Minnesota School of Journalism and Mass Communication.

Sedentary High School Girls Are At Significant Risk For Future Osteoporosis:

Significant numbers of female high school athletes and non-athletes suffer from one or more components of the female athlete triad, a combination of three conditions that can lead to cardiovascular disease, according to a new study by Medical College of Wisconsin researchers in Milwaukee.

Tourists To Caribbean Urged To Pay One Dollar Each To Help Fight Tropical Diseases Of Poverty:

Away from the beaches, resorts, and cruise ships of the Caribbean, there lies a hidden underbelly of poverty and with this poverty comes endemic neglected tropical diseases (NTDs). In an editorial in this month’s PLoS Neglected Tropical Diseases, the journal’s Editor in Chief, Professor Peter Hotez (George Washington University and Sabin Vaccine Institute) proposes that a modest US $1.00 airline or cruise ship tax or a tax on tourist entry could provide a funding mechanism for the Caribbean countries to control these NTDs.

First ‘Smell Map’ Supports Idea That Universal Laws For Smell Are Hard-Wired In Brain:

Is the smell of almonds closer to that of roses or bananas? Weizmann Institute scientists have now answered that question (roses) by showing for the first time that smells can be mapped and the relative distance between various odors determined. Their findings, which appeared recently in Nature Methods, may help scientists to unravel the basic laws underlying our sense of smell, as well as potentially enabling odors to be digitized and transferred via computer in the future.

How Fairness Is Wired In The Brain:

In the biblical story in which two women bring a baby to King Solomon, both claiming to be the mother, he suggests dividing the child so that each woman can have half. Solomon’s proposed solution, meant to reveal the real mother, also illustrates an issue central to economics and moral philosophy: how to distribute goods fairly.

Did Walking On Two Feet Begin With A Shuffle?:

Somewhere in the murky past, between four and seven million years ago, a hungry common ancestor of today’s primates, including humans, did something novel. While temporarily standing on its rear feet to reach a piece of fruit, this protohominid spotted another juicy morsel in a nearby shrub and began shuffling toward it instead of dropping on all fours, crawling to the shrub and standing again.

World’s Rarest Rhinos Make First Video Trap Appearance — Then Toss Camera:

After just a month in operation, specially designed video cameras installed to capture wildlife footage in the jungles of South East Asia have twice recorded remarkable images of a mother and child pair of the world’s rarest rhino.

Altruism In Social Insects Is A Family Affair:

The contentious debate about why insects evolved to put the interests of the colony over the individual has been reignited by new research from the University of Leeds, showing that they do so to increase the chances that their genes will be passed on.

Heat, Not Light, May Be Real Engine Driving Biodiversity:

What causes tropical life to thrive: temperature, or sunlight? The answer is not necessarily “both.” According to a study recently published online in PNAS Early Edition, the explosion of species at the tropics has much more to do with warmth than with light.

Saltwater Sleuths: Seeking Clues To Help Determine Ages Of Fish And Shellfish Populations:

Fishery biologist Sandy Sutherland looks through the lens of the microscope at tiny sections of fish earbones, known as otoliths, each showing annual bands of growth. She carefully counts the bands to determine the age of the fish, then moves on to the next sample. Known as an age reader, Sutherland is one of a small team at NOAA’s Northeast Fisheries Science Center (NEFSC) whose aging work is critical to stock assessments needed to manage the nation’s fishery resources in the Northwest Atlantic Ocean.

Common Aquatic Animal’s Genome Can Capture Foreign DNA:

Long viewed as straitlaced spinsters, sexless freshwater invertebrate animals known as bdelloid rotifers may actually be far more promiscuous than anyone had imagined: Scientists at Harvard University have found that the genomes of these common creatures are chock-full of DNA from plants, fungi, bacteria, and animals.

Mind Over Matter: Monkey Feeds Itself Using Its Brain:

A monkey has successfully fed itself with fluid, well-controlled movements of a human-like robotic arm by using only signals from its brain, researchers from the University of Pittsburgh School of Medicine report in the journal Nature. This significant advance could benefit development of prosthetics for people with spinal cord injuries and those with “locked-in” conditions such as Lou Gehrig’s disease, or amyotrophic lateral sclerosis.

Authentic Viking DNA Retrieved From 1,000-year-old Skeletons:

Although “Viking” literally means “pirate,” recent research has indicated that the Vikings were also traders to the fishmongers of Europe. Stereotypically, these Norsemen are usually pictured wearing a horned helmet but in a new study, Jørgen Dissing and colleagues from the University of Copenhagen, investigated what went under the helmet; the scientists were able to extract authentic DNA from ancient Viking skeletons, avoiding many of the problems of contamination faced by past researchers.

Giant Flying Reptiles Preferred To Walk:

New research into gigantic flying reptiles has found that they weren’t all gull-like predators grabbing fish from the water but that some were strongly adapted for life on the ground.

Childhood Lead Exposure Is Associated With Decreased Brain Volume In Adults:

Childhood exposure to lead is associated with shrinking (“volume loss”) of specific parts of the brain in adulthood, finds a related study in this week’s PLoS Medicine. Dr Kim Cecil and colleagues (University of Cincinnati, USA) studied the association between exposure to lead in the uterus and during early childhood and brain volume in adulthood.

Battling Bird Flu By The Numbers:

A pair of Los Alamos National Laboratory theorists have developed a mathematical tool that could help health experts and crisis managers determine in real time whether an emerging infectious disease such as avian influenza H5N1 is poised to spread globally.

Large-scale Community Protein Annotation — WikiProteins:

Today sees the launch of a new collaborative website initially focusing on proteins and their role in biology and medicine. The WikiProfessional technology underlying the site has been developed based upon the collaborative Wikipedia approach. WikiProteins provides a method for community annotation on a huge scale.

Climate Change Already Affecting U.S. Water, Land, And Biodiversity, Report Finds:

The U.S. Climate Change Science Program (CCSP) has released “Synthesis and Assessment Product 4.3 (SAP 4.3): The Effects of Climate Change on Agriculture, Land Resources, Water Resources, and Biodiversity in the United States.” The CCSP integrates the federal research efforts of 13 agencies on climate and global change. This report is one of the most extensive examinations of climate impacts on U.S. ecosystems.

First Female DNA Sequenced:

Geneticists of Leiden University Medical Centre (LUMC) are the first to determine the DNA sequence of a woman. She is also the first European whose DNA sequence has been determined. Following in-depth analysis, the sequence will be made public, except incidental privacy-sensitive findings. The results will contribute to insights into human genetic diversity.

Why Are Some People Unable To Express Their Emotions?:

Italian investigators have published a new study on the neurobiologic correlates of the inability to express emotions (alexithymia) in the third 2008 issue of Psychotherapy and Psychosomatics.

DNA Clues To Reproductive Behavior:

A species of wild yeast goes through a cycle of sexual reproduction once in every 1,000 asexual generations, according to new research by Imperial biologists published in the PNAS journal in April.

The Secret Behind Silkworm’s Hardy Stomachs:

Silkworms have a unique ability to eat toxic mulberry leaves without feeling ill, and researchers have come one step closer to understanding why: silkworms contain a special digestive enzyme that is not affected by mulberry’s toxic chemicals.

Scientists Announce Top 10 New Species In Last Year:

The International Institute for Species Exploration at Arizona State University and an international committee of taxonomists — scientists responsible for species exploration and classification — has just announced the top 10 new species described in 2007.

More here and here.
Fundamental Building Block In Flowering Plants Evolved Independently, Yet Almost Identically In Ancient Plants:

Biologists have discovered that a fundamental building block in the cells of flowering plants evolved independently, yet almost identically, on a separate branch of the evolutionary tree–in an ancient plant group called lycophytes that originated at least 420 million years ago.

New Research Forces U-turn In Population Migration Theory:

Research led by the University of Leeds has discovered genetic evidence that overturns existing theories about human migration into Island Southeast Asia (covering the Philippines, Indonesia and Malaysian Borneo) – taking the timeline back by nearly 10,000 years.

New Statistical Method Reveals Surprises About Our Ancestry:

A statistical approach to studying genetic variation promises to shed new light on the history of human migration.

There are 48 articles published this week in PLoS ONE, something for everyone. Read, note, comment, blog about and send trackbacks… Here are some of the titles I found cool:
Evidence of Authentic DNA from Danish Viking Age Skeletons Untouched by Humans for 1,000 Years:

Given the relative abundance of modern human DNA and the inherent impossibility for incontestable proof of authenticity, results obtained on ancient human DNA have often been questioned. The widely accepted rules regarding ancient DNA work mainly affect laboratory procedures, however, pre-laboratory contamination occurring during excavation and archaeological-/anthropological handling of human remains as well as rapid degradation of authentic DNA after excavation are major obstacles. We avoided some of these obstacles by analyzing DNA from ten Viking Age subjects that at the time of sampling were untouched by humans for 1,000 years. We removed teeth from the subjects prior to handling by archaeologists and anthropologists using protective equipment. An additional tooth was removed after standard archaeological and anthropological handling. All pre-PCR work was carried out in a “clean- laboratory” dedicated solely to ancient DNA work. Mitochondrial DNA was extracted and overlapping fragments spanning the HVR-1 region as well as diagnostic sites in the coding region were PCR amplified, cloned and sequenced. Consistent results were obtained with the “unhandled” teeth and there was no indication of contamination, while the latter was the case with half of the “handled” teeth. The results allowed the unequivocal assignment of a specific haplotype to each of the subjects, all haplotypes being compatible in their character states with a phylogenetic tree drawn from present day European populations. Several of the haplotypes are either infrequent or have not been observed in modern Scandinavians. The observation of haplogroup I in the present study (<2% in modern Scandinavians) supports our previous findings of a pronounced frequency of this haplogroup in Viking and Iron Age Danes. The present work provides further evidence that retrieval of ancient human DNA is a possible task provided adequate precautions are taken and well-considered sampling is applied.

A Reappraisal of Azhdarchid Pterosaur Functional Morphology and Paleoecology:

Azhdarchid pterosaurs were among the most widespread and successful of pterosaur clades, but their paleoecology remains controversial. Morphological features common to all azhdarchids include a long, shallow rostrum; elongate, cylindrical cervical vertebrae that formed a long and unusually inflexible neck; and proportionally short wings with an abbreviated fourth phalanx. While azhdarchids have been imagined as vulture-like scavengers, sediment probers, swimmers, waders, aerial predators, or stork-like generalists, most recent authors have regarded them as skim-feeders, trawling their lower jaws through water during flight and seizing aquatic prey from the water’s surface. Although apparently widely accepted, the skim-feeding model lacks critical support from anatomy and functional morphology. Azhdarchids lack the many cranial specialisations exhibited by extant skim-feeding birds, most notably the laterally compressed lower jaw and shock absorbing apparatus required for this feeding style. Well-preserved azhdarchid skulls are rare, but their rostra and lower jaws appear to have been sub-triangular in cross-section, and thus dissimilar to those of skim-feeders and sediment probers. Taphonomic data indicates that azhdarchids predominately inhabited inland settings, and azhdarchid morphology indicates that they were poorly suited for all proposed lifestyles bar wading and terrestrial foraging. However, azhdarchid footprints show that their feet were relatively small, padded and slender, and thus not well suited for wading. We argue that azhdarchids were stork- or ground hornbill-like generalists, foraging in diverse environments for small animals and carrion. Proficient terrestrial abilities and a relatively inflexible neck are in agreement with this interpretation.

Function of the Shaw Potassium Channel within the Drosophila Circadian Clock:

In addition to the molecular feedback loops, electrical activity has been shown to be important for the function of networks of clock neurons in generating rhythmic behavior. Most studies have used over-expression of foreign channels or pharmacological manipulations that alter membrane excitability. In order to determine the cellular mechanisms that regulate resting membrane potential (RMP) in the native clock of Drosophila we modulated the function of Shaw, a widely expressed neuronal potassium (K+) channel known to regulate RMP in Drosophila central neurons. We show that Shaw is endogenously expressed in clock neurons. Differential use of clock gene promoters was employed to express a range of transgenes that either increase or decrease Shaw function in different clusters of clock neurons. Under LD conditions, increasing Shaw levels in all clock neurons (LNv, LNd, DN1, DN2 and DN3), or in subsets of clock neurons (LNd and DNs or DNs alone) increases locomotor activity at night. In free-running conditions these manipulations result in arrhythmic locomotor activity without disruption of the molecular clock. Reducing Shaw in the DN alone caused a dramatic lengthening of the behavioral period. Changing Shaw levels in all clock neurons also disrupts the rhythmic accumulation and levels of Pigment Dispersing Factor (PDF) in the dorsal projections of LNv neurons. However, changing Shaw levels solely in LNv neurons had little effect on locomotor activity or rhythmic accumulation of PDF. Based on our results it is likely that Shaw modulates pacemaker and output neuronal electrical activity that controls circadian locomotor behavior by affecting rhythmic release of PDF. The results support an important role of the DN clock neurons in Shaw-mediated control of circadian behavior. In conclusion, we have demonstrated a central role of Shaw for coordinated and rhythmic output from clock neurons.

Blood Parasites in Owls with Conservation Implications for the Spotted Owl (Strix occidentalis):

The three subspecies of Spotted Owl (Northern, Strix occidentalis caurina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n = 17) and unique lineages (n = 12). This high level of sequence diversity is significant because only one Leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls.

iTools: A Framework for Classification, Categorization and Integration of Computational Biology Resources:

The advancement of the computational biology field hinges on progress in three fundamental directions – the development of new computational algorithms, the availability of informatics resource management infrastructures and the capability of tools to interoperate and synergize. There is an explosion in algorithms and tools for computational biology, which makes it difficult for biologists to find, compare and integrate such resources. We describe a new infrastructure, iTools, for managing the query, traversal and comparison of diverse computational biology resources. Specifically, iTools stores information about three types of resources-data, software tools and web-services. The iTools design, implementation and resource meta – data content reflect the broad research, computational, applied and scientific expertise available at the seven National Centers for Biomedical Computing. iTools provides a system for classification, categorization and integration of different computational biology resources across space-and-time scales, biomedical problems, computational infrastructures and mathematical foundations. A large number of resources are already iTools-accessible to the community and this infrastructure is rapidly growing. iTools includes human and machine interfaces to its resource meta-data repository. Investigators or computer programs may utilize these interfaces to search, compare, expand, revise and mine meta-data descriptions of existent computational biology resources. We propose two ways to browse and display the iTools dynamic collection of resources. The first one is based on an ontology of computational biology resources, and the second one is derived from hyperbolic projections of manifolds or complex structures onto planar discs. iTools is an open source project both in terms of the source code development as well as its meta-data content. iTools employs a decentralized, portable, scalable and lightweight framework for long-term resource management. We demonstrate several applications of iTools as a framework for integrated bioinformatics. iTools and the complete details about its specifications, usage and interfaces are available at the iTools web page http://iTools.ccb.ucla.edu.

General Practice and Pandemic Influenza: A Framework for Planning and Comparison of Plans in Five Countries:

Although primary health care, and in particular, general practice will be at the frontline in the response to pandemic influenza, there are no frameworks to guide systematic planning for this task or to appraise available plans for their relevance to general practice. We aimed to develop a framework that will facilitate planning for general practice, and used it to appraise pandemic plans from Australia, England, USA, New Zealand and Canada. We adapted the Haddon matrix to develop the framework, populating its cells through a multi-method study that incorporated the peer-reviewed and grey literature, interviews with general practitioners, practice nurses and senior decision-makers, and desktop simulation exercises. We used the framework to analyse 89 publicly-available jurisdictional plans at similar managerial levels in the five countries. The framework identifies four functional domains: clinical care for influenza and other needs, public health responsibilities, the internal environment and the macro-environment of general practice. No plan addressed all four domains. Most plans either ignored or were sketchy about non-influenza clinical needs, and about the contribution of general practice to public health beyond surveillance. Collaborations between general practices were addressed in few plans, and inter-relationships with the broader health system, even less frequently. This is the first study to provide a framework to guide general practice planning for pandemic influenza. The framework helped identify critical shortcomings in available plans. Engaging general practice effectively in planning is challenging, particularly where governance structures for primary health care are weak. We identify implications for practice and for research.

The Dark Side of the Salad: Salmonella typhimurium Overcomes the Innate Immune Response of Arabidopsis thaliana and Shows an Endopathogenic Lifestyle:

Salmonella enterica serovar typhimurium contaminated vegetables and fruits are considerable sources of human infections. Bacteria present in raw plant-derived nutrients cause salmonellosis, the world wide most spread food poisoning. This facultative endopathogen enters and replicates in host cells and actively suppresses host immune responses. Although Salmonella survives on plants, the underlying bacterial infection mechanisms are only poorly understood. In this report we investigated the possibility to use Arabidopsis thaliana as a genetically tractable host system to study Salmonella-plant interactions. Using green fluorescent protein (GFP) marked bacteria, we show here that Salmonella can infect various Arabidopsis tissues and proliferate in intracelullar cellular compartments. Salmonella infection of Arabidopsis cells can occur via intact shoot or root tissues resulting in wilting, chlorosis and eventually death of the infected organs. Arabidopsis reacts to Salmonella by inducing the activation of mitogen-activated protein kinase (MAPK) cascades and enhanced expression of pathogenesis related (PR) genes. The induction of defense responses fails in plants that are compromised in ethylene or jasmonic acid signaling or in the MKK3-MPK6 MAPK pathway. These findings demonstrate that Arabidopsis represents a true host system for Salmonella, offering unique possibilities to study the interaction of this human pathogen with plants at the molecular level for developing novel drug targets and addressing current safety issues in human nutrition.

Prolonged Visual Experience in Adulthood Modulates Holistic Face Perception:

Using the well-known composite illusion as a marker of the holistic perception of faces, we tested how prolonged visual experience with a specific population of faces (4- to 6-year-old children) modulates the face perception system in adulthood. We report a face composite effect that is larger for adult than children faces in a group of adults without experience with children faces (“children-face novices”), while it is of equal magnitude for adults and children faces in a population of preschool teachers (“children-face experts”). When considering preschool teachers only, we observed a significant correlation between the number of years of experience with children faces and the differential face composite effect between children and adults faces. Participants with at least 10 years of qualitative experience with children faces had a larger composite face effect for children than adult faces. Overall, these observations indicate that even in adulthood face processes can be reshaped qualitatively, presumably to facilitate efficient processing of the differential morphological features of the frequently encountered population of faces.

Cryptic Contamination and Phylogenetic Nonsense:

Ancient human DNA has been treated cautiously ever since the problems related to this type of material were exposed in the early 1990s, but as sequential genetic data from ancient specimens have been key components in several evolutionary and ecological studies, interest in ancient human DNA is on the increase again. It is especially tempting to approach archaeological and anthropological questions through this type of material, but DNA from ancient human tissue is notoriously complicated to work with due to the risk of contamination with modern human DNA. Various ways of authenticating results based on ancient human DNA have been developed to circumvent the problems. One commonly used method is to predict what the contamination is expected to look like and then test whether the ancient human DNA fulfils this prediction. If it does, the results are rejected as contamination, while if it does not, they are often considered authentic. We show here that human contamination in ancient material may well deviate from local allele frequencies or the distributions to be found among the laboratory workers and archaeologists. We conclude that it is not reliable to authenticate ancient human DNA solely by showing that it is different from what would be expected from people who have handled the material.

Brain Networks for Integrative Rhythm Formation:

Performance of externally paced rhythmic movements requires brain and behavioral integration of sensory stimuli with motor commands. The underlying brain mechanisms to elaborate beat-synchronized rhythm and polyrhythms that musicians readily perform may differ. Given known roles in perceiving time and repetitive movements, we hypothesized that basal ganglia and cerebellar structures would have greater activation for polyrhythms than for on-the-beat rhythms. Using functional MRI methods, we investigated brain networks for performing rhythmic movements paced by auditory cues. Musically trained participants performed rhythmic movements at 2 and 3 Hz either at a 1:1 on-the-beat or with a 3:2 or a 2:3 stimulus-movement structure. Due to their prior musical experience, participants performed the 3:2 or 2:3 rhythmic movements automatically. Both the isorhythmic 1:1 and the polyrhythmic 3:2 or 2:3 movements yielded the expected activation in contralateral primary motor cortex and related motor areas and ipsilateral cerebellum. Direct comparison of functional MRI signals obtained during 3:2 or 2:3 and on-the-beat rhythms indicated activation differences bilaterally in the supplementary motor area, ipsilaterally in the supramarginal gyrus and caudate-putamen and contralaterally in the cerebellum. The activated brain areas suggest the existence of an interconnected brain network specific for complex sensory-motor rhythmic integration that might have specificity for elaboration of musical abilities.

Microbiological Implications of Periurban Agriculture and Water Reuse in Mexico City:

Recycled treated or untreated wastewater represents an important health challenge in developing countries due to potential water related microbiological exposure. Our aim was to assess water quality and health implications in a Mexico City periurban agricultural area. A longitudinal study in the Xochimilco wetland area was conducted, and 42 sites were randomly selected from 211, including irrigation water canals and effluents of treatment plants. Sample collection took place during rainy and dry seasons (2000-2001). Microbiological parameters (total coliforms, fecal coliforms, streptococci/enterococci, and bacteria other than Vibrio grown on TCBS), Helicobacter pylori, and physicochemical parameters including trihalomethanes (THM) were determined. Fecal coliforms and fecal streptococci are appropriate indicators of human or animal fecal contamination. Fecal coliform counts surpass Mexican and World Health Organization irrigation water guidelines. Identified microorganisms associated with various pathologies in humans and domestic animals comprise Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp., Enterococcus spp., and Pseudomonas spp; H. pylori was also present in the water. An environmental characteristic of the canal system showed high Total Organic Carbon content and relatively low dissolved oxygen concentration; residual chlorine as a disinfection control is not efficient, but THMs do not represent a problem. During the rainy season, temperature and conductivity were higher; in contrast, pH, dissolved oxygen, ammonia, and residual chlorine were lower. This is related with the continuous load of feces from human and animal sources, and to the aquatic systems, which vary seasonally and exhibit evidence of lower water quality in effluents from treatment plants. There is a need for improvement of wastewater treatment systems, as well as more efficient monitoring, regulation, and enforcement procedures for wastewater disposal into bodies of water.

Why Are Clinicians Not Embracing the Results from Pivotal Clinical Trials in Severe Sepsis? A Bayesian Analysis:

Five pivotal clinical trials (Intensive Insulin Therapy; Recombinant Human Activated Protein C [rhAPC]; Low-Tidal Volume; Low-Dose Steroid; Early Goal-Directed Therapy [EGDT]) demonstrated mortality reduction in patients with severe sepsis and expert guidelines have recommended them to clinical practice. Yet, the adoption of these therapies remains low among clinicians. We selected these five trials and asked: Question 1-What is the current probability that the new therapy is not better than the standard of care in my patient with severe sepsis? Question 2-What is the current probability of reducing the relative risk of death (RRR) of my patient with severe sepsis by meaningful clinical thresholds (RRR >15%; >20%; >25%)? Bayesian methodologies were applied to this study. Odds ratio (OR) was considered for Question 1, and RRR was used for Question 2. We constructed prior distributions (enthusiastic; mild, moderate, and severe skeptic) based on various effective sample sizes of other relevant clinical trials (unfavorable evidence). Posterior distributions were calculated by combining the prior distributions and the data from pivotal trials (favorable evidence). Answer 1-The analysis based on mild skeptic prior shows beneficial results with the Intensive Insulin, rhAPC, and Low-Tidal Volume trials, but not with the Low-Dose Steroid and EGDT trials. All trials’ results become unacceptable by the analyses using moderate or severe skeptic priors. Answer 2-If we aim for a RRR>15%, the mild skeptic analysis shows that the current probability of reducing death by this clinical threshold is 88% for the Intensive Insulin, 62-65% for the Low-Tidal Volume, rhAPC, EGDT trials, and 17% for the Low-Dose Steroid trial. The moderate and severe skeptic analyses show no clinically meaningful reduction in the risk of death for all trials. If we aim for a RRR >20% or >25%, all probabilities of benefits become lower independent of the degree of skepticism. Our clinical threshold analysis offers a new bedside tool to be directly applied to the care of patients with severe sepsis. Our results demonstrate that the strength of evidence (statistical and clinical) is weak for all trials, particularly for the Low-Dose Steroid and EGDT trials. It is essential to replicate the results of each of these five clinical trials in confirmatory studies if we want to provide patient care based on scientifically sound evidence.

A Critical Assessment of the Effects of Bt Transgenic Plants on Parasitoids:

The ecological safety of transgenic insecticidal plants expressing crystal proteins (Cry toxins) from the bacterium Bacillus thuringiensis (Bt) continues to be debated. Much of the debate has focused on nontarget organisms, especially predators and parasitoids that help control populations of pest insects in many crops. Although many studies have been conducted on predators, few reports have examined parasitoids but some of them have reported negative impacts. None of the previous reports were able to clearly characterize the cause of the negative impact. In order to provide a critical assessment, we used a novel paradigm consisting of a strain of the insect pest, Plutella xylostella (herbivore), resistant to Cry1C and allowed it to feed on Bt plants and then become parasitized by Diadegma insulare, an important endoparasitoid of P. xylostella. Our results indicated that the parasitoid was exposed to a biologically active form of the Cy1C protein while in the host but was not harmed by such exposure. Parallel studies conducted with several commonly used insecticides indicated they significantly reduced parasitism rates on strains of P. xylostella resistant to these insecticides. These results provide the first clear evidence of the lack of hazard to a parasitoid by a Bt plant, compared to traditional insecticides, and describe a test to rigorously evaluate the risks Bt plants pose to predators and parasitoids.

Environmental Factors Contributing to the Spread of H5N1 Avian Influenza in Mainland China:

Since late 2003, highly pathogenic avian influenza (HPAI) outbreaks caused by infection with H5N1 virus has led to the deaths of millions of poultry and more than 10 thousands of wild birds, and as of 18-March 2008, at least 373 laboratory-confirmed human infections with 236 fatalities, have occurred. The unrestrained worldwide spread of this disease has caused great anxiety about the potential of another global pandemic. However, the effect of environmental factors influencing the spread of HPAI H5N1 virus is unclear. A database including incident dates and locations was developed for 128 confirmed HPAI H5N1 outbreaks in poultry and wild birds, as well as 21 human cases in mainland China during 2004-2006. These data, together with information on wild bird migration, poultry densities, and environmental variables (water bodies, wetlands, transportation routes, main cities, precipitation and elevation), were integrated into a Geographical Information System (GIS). A case-control design was used to identify the environmental factors associated with the incidence of the disease. Multivariate logistic regression analysis indicated that minimal distance to the nearest national highway, annual precipitation and the interaction between minimal distance to the nearest lake and wetland, were important predictive environmental variables for the risk of HPAI. A risk map was constructed based on these factors. Our study indicates that environmental factors contribute to the spread of the disease. The risk map can be used to target countermeasures to stop further spread of the HPAI H5N1 at its source.

Orientation Sensitivity at Different Stages of Object Processing: Evidence from Repetition Priming and Naming:

An ongoing debate in the object recognition literature centers on whether the shape representations used in recognition are coded in an orientation-dependent or orientation-invariant manner. In this study, we asked whether the nature of the object representation (orientation-dependent vs orientation-invariant) depends on the information-processing stages tapped by the task. We employed a repetition priming paradigm in which briefly presented masked objects (primes) were followed by an upright target object which had to be named as rapidly as possible. The primes were presented for variable durations (ranging from 16 to 350 ms) and in various image-plane orientations (from 0° to 180°, in 30° steps). Significant priming was obtained for prime durations above 70 ms, but not for prime durations of 16 ms and 47 ms, and did not vary as a function of prime orientation. In contrast, naming the same objects that served as primes resulted in orientation-dependent reaction time costs. These results suggest that initial processing of object identity is mediated by orientation-independent information and that orientation costs in performance arise when objects are consolidated in visual short-term memory in order to be reported.

How Do US Journalists Cover Treatments, Tests, Products, and Procedures? An Evaluation of 500 Stories:

* The daily delivery of news stories about new treatments, tests, products, and procedures may have a profound–and perhaps harmful–impact on health care consumers.
* A US Web site project, HealthNewsReview.org (http://HealthNewsReview.org/), modeled after similar efforts in Australia and Canada, evaluates and grades health news coverage, notifying journalists of their grades.
* After almost two years and 500 stories, the project has found that journalists usually fail to discuss costs, the quality of the evidence, the existence of alternative options, and the absolute magnitude of potential benefits and harms.
* Reporters and writers have been receptive to the feedback; editors and managers must be reached if change is to occur.
* Time (to research stories), space (in publications and broadcasts), and training of journalists can provide solutions to many of the journalistic shortcomings identified by the project.

Disease Mongering Is Now Part of the Global Health Debate:

Disease mongering is the selling of sickness that widens the boundaries of illness in order to grow markets for those who sell and deliver treatments. It is a process that turns healthy people into patients, causes iatrogenic harm, and wastes precious resources [1]. Disease mongering is the contemporary form of “medicalisation.” It is a process now driven by both corporate and professional interests, and it has become part of the global debate about health care. International consumer groups now target drug company-backed disease mongering as a wasteful threat to public health [2], while the global pharmaceutical industry has been forced to defend its promotion of “lifestyle” medicines for problems like slimming and sexual difficulties [3].

False Hopes, Unwarranted Fears: The Trouble with Medical News Stories:

On April 26, 2007, ABC World News, the American Broadcasting Corporation’s flagship television news program, aired a “good news” story about a new test for prostate cancer [1]. Against a background of a dramatic graphic showing that 1.6 million American men undergo prostate biopsy each year, the presenter announced: “Researchers at Johns Hopkins say they have developed a more accurate blood screening test.” The story was based on a new study examining the performance of early prostate cancer antigen-2 as a serum marker for prostate cancer [2]. Unfortunately, ABC failed to disclose one crucial fact: the principal investigator of this study receives a share of the royalty sales of the test and is a paid consultant to the test’s manufacturer [3].

Sperm Sociality: Cooperation, Altruism, and Spite:

A swimming sperm cell appears to perfectly capture the individualist Darwinian struggle, as it frantically races onwards towards a waiting egg. Consistent with this imagery, sperm morphology and behaviour in many organisms appears exquisitely designed to maximise the chances of fertilisation of each individual sperm cell [1]. However, there are numerous less obliging cases where sperm seem poorly suited to the task, even to the extent that the majority of sperm in an ejaculate may be infertile [2,3]. Why would such sperm evolve?

Sniffing Out the Right Address:

Olfactory systems in organisms ranging from invertebrates to mammals distinguish between odors using an array of olfactory neurons that express different olfactory receptors–usually just one receptor in a given neuron. Since an organism’s genome can encode hundreds of olfactory receptors, researchers have struggled to understand how a single olfactory neuron decides which receptor to express. In Drosophila, it seems that regulatory elements upstream of olfactory receptor genes act like zip codes to direct the expression of each gene to the appropriate class of olfactory neurons.

When Skin Damage Causes Death:

Our skin routinely shields us from microbes, allergens, and other environmental assaults, a yeoman’s service we often take for granted–until that barrier is breached. In response to injury, be it a simple cut or a deep wound, keratinocytes, the cells that form the epidermal layer, proliferate and dispatch chemical messengers to enlist the healing services of immune cells. But new research shows that sometimes damaged skin can send the wrong message to its immune cell partners. Rather than recruiting immune cells to repair a wound, Raphael Kopan and colleagues report, defective skin can trigger a systemic, ultimately fatal immune response.

Climate Change Does Double-whammy To Animals In Seasonal Environments:

Plant-eating animals in highly seasonal environments, such as the Arctic, are struggling to locate nutritious food as a result of climate change, according to research that will be published in the 21 May 2008 online edition of the journal Proceedings of the Royal Society B. Led by Penn State Associate Professor of Biology Eric Post, the research, which focused on caribou, suggests that not only are these animals arriving at their breeding grounds too late in the season to enjoy the peak availability of food–the focus of previous research by Post–but they also are suffering from a reduced ability to locate the few high-quality plants that remain before these plants, too, become unavailable.

Related….
Tidal Cycle Could Amplify Global-warming Related Sea-level Rises:

The results of several scientific studies conducted since 1993 have confirmed a 3.2 cm sea level rise. Although this variation might appear negligible, it has in fact turned out to be twice as high as that recorded over the whole of the previous century. This increase in sea level is a consequence of global warming. When sea temperature rises, the sea expands and therefore occupies a greater volume. This phenomenon is now well known to scientists, but other processes that have received less research attention, such as the tidal cycle, seem to contribute at global scale just as much to changes in sea level.

What Is The Value Of Biodiversity To Our Collective Future?:

What will the loss of biodiversity cost us in the long term? How much do national economies need to invest now in order to stop the trend? And what price will we have to pay if we do not act? These are the questions the TEEB – The Economics of Eco-systems and Biodiversity – project is seeking to answer.

Honey Bee Losses Continue To Rise In U.S.:

Colony Collapse Disorder, diseases, parasitic mites and other stressors continue to take a devastating toll on U.S. honey bee populations, but Pennsylvania beekeepers on average fared better than their counterparts nationally during this past winter, according to apiculture experts in Penn State’s College of Agricultural Sciences.

Male-Male Courtship Pattern Shaped By Emergence Of A New Gene In Fruit Flies:

When a young gene known as sphinx is inactivated in the common fruit fly, it leads to increased male-male courtship, scientists report in the May 27, 2008, issue of the Proceedings of the National Academy of Sciences. High levels of male-male courtship are widespread in many fly species, but not in Drosophila melanogaster, the tiny insect that has been a mainstay of genetic research for more than a century.

Fixing The Education Digital Disconnect One Video Game At A Time: FAS Launches Immune Attack:

The Federation of American Scientists (FAS) has just launched Immune Attack TM, an exciting, fun and fast-moving video game that teaches the critical scientific facts of immunology.

Gene Mutations In Mice Mimic Human-like Sleep Disorder:

Mutations in two genes that control electrical excitability in a portion of the brain involved in sleep create a human-like insomnia disorder in mice, UT Southwestern Medical Center researchers have found. The findings may help scientists better understand the disorder and provide an animal model for developing treatments.

Food-related Clock In The Brain Identified:

In investigating the intricacies of the body’s biological rhythms, scientists at Beth Israel Deaconess Medical Center (BIDMC) have discovered the existence of a “food-related clock” which can supersede the “light-based” master clock that serves as the body’s primary timekeeper.

High-school Girls Who Consider Themselves Attractive Are More Likely To Be Targets For Bullying:

University of Alberta Educational Psychology PhD student Lindsey Leenaars has completed a study that assessed what types of high school students are being indirectly victimized. This includes being involved in emotionally damaging scenarios such as receiving hurtful anonymous notes, being socially excluded, or having rumours spread about them, including threats of physical harm.

Estrogen Fuels Female Need For Power And Control:

New University of Michigan psychology research suggests that the sex hormone estrogen may be for women what testosterone is for men: The fuel of power.

Video Games Can Make Us Creative If Spark Is Right:

Video games that energize players and induce a positive mood could also enhance creativity, according to media researchers. However, the study also finds that players who were not highly energized and had a negative mood, registered the highest creativity.

Public Schools As Good As Private Schools In Raising Math Scores, Study Says:

Students in public schools learn as much or more math between kindergarten and fifth grade as similar students in private schools, according to a new University of Illinois study of multi-year, longitudinal data on nearly 10,000 students.

Inferring Human Colonization History Using a Copying Model:

Humans like to tell stories. Amongst the most captivating is the story of the global spread of modern humans from their original homeland in Africa. Traditionally this has been the preserve of anthropologists, but geneticists are starting to make an important contribution. However, genetic evidence is typically analyzed in the context of anthropological preconceptions. For genetics to provide an accurate and detailed history without reference to anthropology, methods are required that translate DNA sequence data into histories. We introduce a statistical method that has three virtues. First, it is based on a copying model that incorporates the block-by-block inheritance of DNA from one generation to the next. This allows it to capture the rich information provided by patterns of DNA sharing across the whole genome. Second, its parameter space includes an enormous number of possible colonization scenarios, meaning that inferences are correspondingly rich in detail. Third, the inferred colonization scenario is determined algorithmically. We have applied this method to data from 53 human populations and find that while the current consensus is broadly supported, some populations have surprising histories. This scenario can be viewed as a movie, making it transparent where statistical analysis ends and where interpretation begins.

Evolution of Taxis Responses in Virtual Bacteria: Non-Adaptive Dynamics:

Here, we study how signalling networks mediating chemotaxis could have evolved. We simulated the evolution of virtual bacteria, which can explore their environment by alternating between swimming and tumbling. The tumbling frequency is dictated by the output of a signalling network that senses extracellular nutrient levels, while the bacteria’s reproductive success is determined by their ability to find nutrients. Under conditions of abundant food, we find that bacteria quickly evolve signalling networks that enable effective chemotaxis, where increasing nutrient levels increase tumbling frequency. Our findings provide explanation for network dynamics underlying similar behaviour as observed in certain mutant strains of Escherichia coli and in other bacterial species. Conversely, wild-type E. coli respond to increasing nutrient levels by decreasing their tumbling frequency and adapting to constant attractant levels. We observe such adaptive network dynamics when we repeat evolutionary simulations under conditions of scarce food. These findings suggest that (i) adaptation is not necessary for effective chemotaxis, (ii) an ancestral minimal chemotaxis system could have used a simple coupling between the signalling network and the metabolic state, and (iii) environmental conditions are one of the determining factors for the evolution of adaptive responses.

Some Like It Hot! Structure Of Receptor For Hot Chili Pepper And Pain Revealed:

You can now not only feel the spicy kick of a jalapeno pepper, you can also see it in full 3D, thanks to researchers at Baylor College of Medicine in Houston.

Early Life Exposure To Cats May Reduce Risk Of Childhood Allergies And Asthma Symptoms:

A study released by researchers at the Columbia Center for Children’s Environmental Health (CCCEH) at Columbia University’s Mailman School of Public Health, shows that cat ownership may have a protective effect against the development of asthma symptoms in young children at age five. The study, published by the Journal of Allergy and Clinical Immunology, found that children with cats in the home were more likely to have made allergy-related antibodies to cats. At three years of age, children who had made antibodies to cats early in life were more likely to have wheeze, a respiratory symptom associated with asthma. However, by age five, the same children who had grown up with a cat were then found to be less likely to have wheeze.

Kangaroos Threaten One Of Australia’s Last Remaining Original Grasslands, And Endangered Animals:

Australian Department of Defence is currently culling hundreds of kangaroos on the outskirts of the capital Canberra that have produced heated discussions and hit international headlines. Australia’s iconic animal has multiplied so much over recent years that Canberra now has three times as many kangaroos as inhabitants. The situation is particularly critical at two enclosed military sites on the outskirts of the city, which form an ideal refuge for the eastern grey kangaroo (Macropus giganteus).

Ancient Amphibian: Debate Over Origin Of Frogs And Salamanders Settled With Discovery Of Missing Link:

The description of an ancient amphibian that millions of years ago swam in quiet pools and caught mayflies on the surrounding land in Texas has set to rest one of the greatest current controversies in vertebrate evolution. The discovery was made by a research team led by scientists at the University of Calgary.

Unique Adaptive Evolution Found In Snake Proteins Provide New Insight Into Vertebrate Physiology:

Prior to the advent of large sequence datasets, it was assumed that innovation and divergence at the morphological and physiological level would be easily explained at the molecular level. Molecular explanations for physiological adaptations have, however, been rare. Pollock and colleagues now provide evidence that major macroevolutionary changes in snakes (e.g., physiological and metabolic adaptations and venom evolution) have been accompanied by massive functional redesign of core metabolic proteins.

New Family Of Gecko Discovered:

Researchers at the University of Minnesota’s Bell Museum of Natural History and Pennsylvania’s Villanova University have discovered a new family of gecko, the charismatic large-eyed lizard popularized by car insurance commercials.

Reproductive Plasticity Revealed: Neotropical Treefrog Can Choose To Lay Eggs In Water Or On Land:

When frogs reproduce, like all vertebrates, they either lay their eggs in water or on land — with one exception, according to new research by a team of Boston University scientists who discovered a treefrog (Dendropsophus ebraccatus) in Panama that reproduces both ways. The neotropical frog makes a behavioral decision to lay egg masses aquatically in a pond or terrestrially on the overhanging plants above a pond, where the newly-hatched tadpoles simply fall into the water.

Invasion Of Gigantic Burmese Pythons In South Florida Appears To Be Rapidly Expanding:

The invasion of gigantic Burmese pythons in South Florida appears to be rapidly expanding, according to a new report from a University of Florida researcher who’s been chasing the snakes since 2005.

How Can We Measure The Emotional States Of Animals?:

Rats housed in standard conditions show a stronger response to the loss of an expected food reward than those housed in enriched conditions, perhaps indicating a more negative emotional state, according to new research by scientists at Bristol University Veterinary School, published recently in Royal Society Biology Letters.

Lifestyle Evolution Of Wild Marine Bacteria: Free-floating Cells Share With Attached Relatives:

Marine bacteria in the wild organize into professions or lifestyle groups that partition many resources rather than competing for them, so that microbes with one lifestyle, such as free-floating cells, flourish in proximity with closely related microbes that may spend life attached to zooplankton or algae.

Multiple New Species Of Fruit Flies With Overlapping Niches Discovered:

Evidence of physically similar species hidden within plant tissues suggest that diversity of neotropical herbivorous insects may not simply be a function of plant architecture, but may also reflect the great age and area of the neotropics.

First Dinosaur Tracks Discovered On Arabian Peninsula:

Scientists have discovered the first dinosaur tracks on the Arabian Peninsula. They have discovered evidence of a large ornithopod dinosaur, as well as a herd of 11 sauropods walking along a Mesozoic coastal mudflat in what is now the Republic of Yemen.

There are 61 articles published in PLoS ONE this week. Here are some of the highlights, look around for more and please comment, rate, and send trackbacks:
Adaptive Evolution and Functional Redesign of Core Metabolic Proteins in Snakes:

Adaptive evolutionary episodes in core metabolic proteins are uncommon, and are even more rarely linked to major macroevolutionary shifts. We conducted extensive molecular evolutionary analyses on snake mitochondrial proteins and discovered multiple lines of evidence suggesting that the proteins at the core of aerobic metabolism in snakes have undergone remarkably large episodic bursts of adaptive change. We show that snake mitochondrial proteins experienced unprecedented levels of positive selection, coevolution, convergence, and reversion at functionally critical residues. We examined Cytochrome C oxidase subunit I (COI) in detail, and show that it experienced extensive modification of normally conserved residues involved in proton transport and delivery of electrons and oxygen. Thus, adaptive changes likely altered the flow of protons and other aspects of function in CO, thereby influencing fundamental characteristics of aerobic metabolism. We refer to these processes as “evolutionary redesign” because of the magnitude of the episodic bursts and the degree to which they affected core functional residues. The evolutionary redesign of snake COI coincided with adaptive bursts in other mitochondrial proteins and substantial changes in mitochondrial genome structure. It also generally coincided with or preceded major shifts in ecological niche and the evolution of extensive physiological adaptations related to lung reduction, large prey consumption, and venom evolution. The parallel timing of these major evolutionary events suggests that evolutionary redesign of metabolic and mitochondrial function may be related to, or underlie, the extreme changes in physiological and metabolic efficiency, flexibility, and innovation observed in snake evolution.

See also this…..
First Dinosaur Tracks from the Arabian Peninsula:

The evolutionary history of Mesozoic terrestrial vertebrates from the Arabian Peninsula is virtually unknown. Despite vast exposures of rocky outcrops, only a handful of fossils have yet been described from the region. Here we report a multi-taxon dinosaur track assemblage near Madar village, 47 km north of Sana’a, Republic of Yemen. This represents the first dinosaur tracksite from the Arabian Peninsula, and the only multi-taxon dinosaur ichnosite in the Middle East. Measurements were taken directly from trackway impressions, following standard ichnological conventions. The presence of bipedal trackmakers is evidenced by a long series of pes imprints preserving smoothly rounded posterior margins, no evidence of a hallux, bluntly rounded digit tips and digital divarication angles characteristic of ornithopod dinosaurs. Nearby, eleven parallel quadrupedal trackways document a sauropod herd that included large and small individuals traveling together. Based on the morphology of manus impressions along with a narrow-gauged stance, the quadrupedal trackways were made by non-titanosauriform neosauropods. Additional isolated tracks and trackways of sauropod and ornithopod dinosaurs are preserved nearby. Taken together, these discoveries present the most evocative window to date into the evolutionary history of dinosaurs of the Arabian Peninsula. Given the limited Mesozoic terrestrial record from the region, this discovery is of both temporal and geographic significance, and massive exposures of similarly-aged outcrops nearby offer great promise for future discoveries.

Anomalous Hypothalamic Responses to Humor in Cataplexy:

Cataplexy is observed in a subset of patients with narcolepsy and affects approximately 1 in 2,000 persons. Cataplexy is most often triggered by strong emotions such as laughter, which can result in transient, yet debilitating, muscle atonia. The objective of this study was to examine the neural systems underlying humor processing in individuals with cataplexy. While undergoing functional Magnetic Resonance Imaging (fMRI), we showed ten narcolepsy-cataplexy patients and ten healthy controls humorous cartoons. In addition, we examined the brain activity of one subject while in a full-blown cataplectic attack. Behavioral results showed that participants with cataplexy rated significantly fewer humorous cartoons as funny compared to controls. Concurrent fMRI showed that patients, when compared to controls and in the absence of overt cataplexy symptoms, showed pronounced activity in the emotional network including the ventral striatum and hypothalamus while viewing humorous versus non-humorous cartoons. Increased activity was also observed in the right inferior frontal gyri -a core component of the inhibitory circuitry. In comparison, the one subject who experienced a cataplectic attack showed dramatic reductions in hypothalamic activity. These findings suggest an overdrive of the emotional circuitry and possible compensatory suppression by cortical inhibitory regions in cataplexy. Moreover, during cataplectic attacks, the hypothalamus is characterized by a marked decrease in activity similar to that observed during sleep. One possible explanation for these findings is an initial overdrive and compensatory shutdown of the hypothalamus resulting in full cataplectic symptoms.

Missing Girls in India: Infanticide, Feticide and Made-to-Order Pregnancies? Insights from Hospital-Based Sex-Ratio-at-Birth over the Last Century:

There are 44 million missing women in India. Gender bias; neglect of girls, infanticides and feticides are responsible. The sex ratio at birth can be used to examine the influence of antenatal sex selection on the sex ratio. Records from 321,991 deliveries at one hospital over 11 decades were utilized. The middle year in each decade was taken as representative of the decade. Data from 33,524 deliveries were then analyzed. Data for each decade was combined with that of previous decades and compared to the data of subsequent decades to look for any change in the trend. Sex ratio in the second children against sex of the first child was studied separately. The mean sex ratio for the 110 years examined was 910 girls to 1000 boys (95% CI; 891 to 930). The sex ratio dropped significantly from 935 (CI: 905 to 967) before 1979, to 892 (CI: 868 to 918) after 1980 (P = 0.04). The sex ratio in the second child was significantly lower if the first child was a girl [716 (CI: 672 to 762] (P<0.001). On the other hand, there was an excess of girls born to mothers whose first child was boy [1140 girls per 1000 boys (CI: 1072 to 1212 P<0.001)]. The sex ratio fell significantly after 1980 when ultra sound machines for antenatal sex determination became available. The sex ratio in second children if the first was a girl was even lower. Sex selective abortions after antenatal sex determination are thus implicated. However data on second children especially the excess of girls born to mothers who have a previous boy seen in the decade before the advent of antenatal ultra sound machines, suggests that other means of sex selection are also used.

Maternal Programming of Sexual Behavior and Hypothalamic-Pituitary-Gonadal Function in the Female Rat:

Variations in parental care predict the age of puberty, sexual activity in adolescence and the age at first pregnancy in humans. These findings parallel descriptions of maternal effects on phenotypic variation in reproductive function in other species. Despite the prevalence of such reports, little is known about potential biological mechanisms and this especially true for effects on female reproductive development. We examined the hypothesis that parental care might alter hypothalamic-pituitary-ovarian function and thus reproductive function in the female offspring of rat mothers that vary pup licking/grooming (LG) over the first week postpartum. As adults, the female offspring of Low LG mothers showed 1) increased sexual receptivity; 2) increased plasma levels of luteinizing hormone (LH) and progesterone at proestrus; 3) an increased positive-feedback effect of estradiol on both plasma LH levels and gonadotropin releasing-hormone (GnRH) expression in the medial preoptic region; and 4) increased estrogen receptor α (ERα) expression in the anterioventral paraventricular nucleus, a system that regulates GnRH. The results of a cross-fostering study provide evidence for a direct effect of postnatal maternal care as well as a possible prenatal influence. Indeed, we found evidence for increased fetal testosterone levels at embryonic day 20 in the female fetuses of High compared to Low LG mothers. Finally, the female offspring of Low LG mothers showed accelerated puberty compared to those of High LG mothers. These data suggest maternal effects in the rat on the development of neuroendocrine systems that regulate female sexual behaviour. Together with studies revealing a maternal effect on the maternal behavior of the female offspring, these findings suggest that maternal care can program alternative reproductive phenotypes in the rat through regionally-specific effects on ERα expression.

The Parallel Worm Tracker: A Platform for Measuring Average Speed and Drug-Induced Paralysis in Nematodes:

Caenorhabditis elegans locomotion is a simple behavior that has been widely used to dissect genetic components of behavior, synaptic transmission, and muscle function. Many of the paradigms that have been created to study C. elegans locomotion rely on qualitative experimenter observation. Here we report the implementation of an automated tracking system developed to quantify the locomotion of multiple individual worms in parallel. Our tracking system generates a consistent measurement of locomotion that allows direct comparison of results across experiments and experimenters and provides a standard method to share data between laboratories. The tracker utilizes a video camera attached to a zoom lens and a software package implemented in MATLAB®. We demonstrate several proof-of-principle applications for the tracker including measuring speed in the absence and presence of food and in the presence of serotonin. We further use the tracker to automatically quantify the time course of paralysis of worms exposed to aldicarb and levamisole and show that tracker performance compares favorably to data generated using a hand-scored metric. Although this is not the first automated tracking system developed to measure C. elegans locomotion, our tracking software package is freely available and provides a simple interface that includes tools for rapid data collection and analysis. By contrast with other tools, it is not dependent on a specific set of hardware. We propose that the tracker may be used for a broad range of additional worm locomotion applications including genetic and chemical screening.

Effects of Gape and Tooth Position on Bite Force and Skull Stress in the Dingo (Canis lupus dingo) Using a 3-Dimensional Finite Element Approach:

Models of the mammalian jaw have predicted that bite force is intimately linked to jaw gape and to tooth position. Despite widespread use, few empirical studies have provided evidence to validate these models in non-human mammals and none have considered the influence of gape angle on the distribution of stress. Here using a multi-property finite element (FE) model of Canis lupus dingo, we examined the influence of gape angle and bite point on both bite force and cranial stress. Bite force data in relation to jaw gape and along the tooth row, are in broad agreement with previously reported results. However stress data showed that the skull of C. l. dingo is mechanically suited to withstand stresses at wide gapes; a result that agreed well with previously held views regarding carnivoran evolution. Stress data, combined with bite force information, suggested that there is an optimal bite angle of between 25° and 35° in C. l. dingo. The function of these rather small bite angles remains unclear.

Imagine Jane and Identify John: Face Identity Aftereffects Induced by Imagined Faces:

It is not known whether prolonged exposure to perceived and imagined complex visual images produces similar shifts in subsequent perception through selective adaptation. This question is important because a positive finding would suggest that perception and imagery of visual stimuli are mediated by shared neural networks. In this study, we used a selective adaptation procedure designed to induce high-level face-identity aftereffects–a phenomenon in which extended exposure to a particular face facilitates recognition of subsequent faces with opposite features while impairing recognition of all other faces. We report here that adaptation to either real or imagined faces produces a similar shift in perception and that identity boundaries represented in real and imagined faces are equivalent. Together, our results show that identity information contained in imagined and real faces produce similar behavioral outcomes. Our findings of high-level visual aftereffects induced by imagined stimuli can be taken as evidence for the involvement of shared neural networks that mediate perception and imagery of complex visual stimuli.

Linking Social and Vocal Brains: Could Social Segregation Prevent a Proper Development of a Central Auditory Area in a Female Songbird?:

Direct social contact and social interaction affect speech development in human infants and are required in order to maintain perceptual abilities; however the processes involved are still poorly known. In the present study, we tested the hypothesis that social segregation during development would prevent the proper development of a central auditory area, using a “classical” animal model of vocal development, a songbird. Based on our knowledge of European starling, we raised young female starlings with peers and only adult male tutors. This ensured that female would show neither social bond with nor vocal copying from males. Electrophysiological recordings performed when these females were adult revealed perceptual abnormalities: they presented a larger auditory area, a lower proportion of specialized neurons and a larger proportion of generalist sites than wild-caught females, whereas these characteristics were similar to those observed in socially deprived (physically separated) females. These results confirmed and added to earlier results for males, suggesting that the degree of perceptual deficiency reflects the degree of social separation. To our knowledge, this report constitutes the first evidence that social segregation can, as much as physical separation, alter the development of a central auditory area.

Evolution and Creationism in America’s Classrooms: A National Portrait:

We advance this long tradition of surveying teachers with reports from the first nationally representative survey of teachers concerning the teaching of evolution. The survey permits a statistically valid and current portrait of US science teachers that complements US and international surveys of the general public on evolution and scientific literacy [2,24] and on evolution in the classroom [3,25]. Between March 5 and May 1, 2007, 939 teachers participated in the study, either by mail or by completing an identical questionnaire online. Our overall response rate of 48% yielded a sample that may be generalized to the population of all public school teachers who taught a high school-level biology course in the 2006-2007 academic year, with all percentage estimates reported in this essay’s tables and figures having a margin of error of no more than 3.2% at the 95% confidence level. Detailed discussion of the methods of the survey and assessments of non-response can be found in Text S1. Our results confirm wide variance in classroom instruction and indicate a clear need to focus not only on state and federal policy decisions, but on the everyday instruction in American classrooms.

Circadian Transcription Contributes to Core Period Determination in Drosophila:

The existence of circadian clocks, which allow organisms to predict daily changes in their environments, have been recognized for centuries, yet only recently has the molecular machinery responsible for their generation been uncovered. The current model in animals posits that interlocked feedback loops of transcription-translation produce these 24-hour rhythms. In fruit flies, the transcription loop contains a key activator complex, composed of the transcription factors Clock and Cycle. This CLK-CYC complex stimulates the synthesis of repressor proteins like Period and Timeless, which repress the activator complex. The synthesis-repression cycle takes precisely 24 hours under environmental conditions that influence the circadian period. An almost identical process relies on the ortholog proteins CLK-BMAL in mammals. Recent findings have challenged the transcription-translation feedback model and suggest that circadian transcription is an output process and that the post-translational modification of clock proteins is the real central pacemaker mechanism. In the present study, we have manipulated the levels and strength of the CLK-CYC complex. The results demonstrate that its activity is vital for proper period determination and thus indicate that the transcriptional feedback loop is part of the core circadian mechanism.

Regulatory RNAs: Have mRNA Untranslated Regions Joined the Party?:

In the last decade or so, we have become familiar with the discovery of new classes of nuclear-encoded regulators (see Glossary) as fundamental controllers of gene expression. Each new discovery has again highlighted the incomplete nature of our understanding of the genome and its regulation. First, small interfering RNAs (siRNAs) demonstrated that RNA molecules are not merely components of the cellular machinery (such as tRNAs and rRNAs) or gene-expression intermediates (mRNAs), but can function as potent trans-acting regulators of specific genes. MicroRNAs (miRNAs) continued this theme and now attract much attention among basic scientists and clinicians alike, both as potential regulators of most human genes and as potential diagnostic tools. In this issue of PLoS Medicine, a research article by Shigetada Teshima-Kondo and colleagues supports the suggestion that another class of regulatory RNAs exists [1]. Furthermore, this class could be the largest to date, since potential members are contained within every mRNA.

The Allure of the Few:

Population ecology–the science of what makes animal and plant populations change, persist, or go extinct–is the most theoretical and mathematical of all ecological disciplines, yet it yields a huge number of practical benefits. When conservation agencies wish to protect a threatened species, but are up against a tight budget and real-world logistical constraints, they use population models to tell them how large an area to reserve and how it should be connected to other habitats, so as to minimise the species’ risk of extinction. In short, population ecology tells us how to get the best “bang for our buck” [1]. Similarly, fishery managers face the perennial issue of determining how heavily they can exploit a fluctuating fish stock without over-harvesting and causing a crash (or extinction). Again, population models, of various complexities, provide guidance in setting fishing quotas and no-take areas [2].

‘Mitochondrial Eve’ Research: Humanity Was Genetically Divided For 100,000 Years:

The human race was divided into two separate groups within Africa for as much as half of its existence, says a Tel Aviv University mathematician. Climate change, reduction in populations and harsh conditions may have caused and maintained the separation.

Simple Artificial Cell Created From Scratch To Study Cell Complexity:

A team of Penn State researchers has developed a simple artificial cell with which to investigate the organization and function of two of the most basic cell components: the cell membrane and the cytoplasm–the gelatinous fluid that surrounds the structures in living cells. The work could lead to the creation of new drugs that take advantage of properties of cell organization to prevent the development of diseases. The team’s findings will be published later this month in the Journal of the American Chemical Society.

Crystal (Eye) Ball: Visual System Equipped With ‘Future Seeing Powers’:

Catching a football. Maneuvering through a room full of people. Jumping out of the way when a golfer yells “fore.” Most would agree these seemingly simple actions require us to perceive and quickly respond to a situation. Assistant Professor of Cognitive Science at Rensselaer Polytechnic Institute Mark Changizi argues they require something more — our ability to foresee the future.

Weather, Waves And Wireless: Super Strength Signalling:

A new study from the University of Leicester has discovered a particular window of time when mobile signals and radio waves are ‘super strength’ — allowing them to be clearer and travel greater distances, potentially interfering with other systems.

Gravity-defying Bird Beak Mystery Solved: Shorebirds Benefit From Surface Tension:

As Charles Darwin showed nearly 150 years ago, bird beaks are exquisitely adapted to the birds’ feeding strategy. A team of MIT mathematicians and engineers has now explained exactly how some shorebirds use their long, thin beaks to defy gravity and transport food into their mouths.

Climbing As Easy As Walking For Smaller Primates:

Smaller primates expend no more energy climbing than they do walking, Duke University researchers have found. This surprising discovery may explain the evolutionary edge that encouraged the tiny ancestors of modern humans, apes and monkeys to climb into the trees about 65 million years ago and stay there.

Parrot Fossil 55 Million Years Old Discovered In Scandinavia:

Palaeontologists have discovered fossil remains in Scandinavia of parrots dating back 55 million years. Reported May 14 in the journal Palaeontology, the fossils indicate that parrots once flew wild over what is now Norway and Denmark.

Success By Learning: Smallest Predator Recognizes Prey By Its Shape:

The Etruscan shrew (Suncus etruscus) is one of the world’s smallest mammals. It is about four centimetres long and weighs merely two grams. Being a nocturnal animal, it hunts predominantly with its sense of touch. Professor Michael Brecht (Bernstein Center for Computional Neuroscience, Berlin) now reported on the particularities of its hunting behaviour at the international conference “Development and function of somatosensation and pain” at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany. “As quick as a flash, the Etruscan shrew scans its prey and adapts, when necessary, its hunting strategy,” explained Brecht in his talk. “Thus, no prey escapes.”

Monkey Studies Important For Brain Science:

Studies with non-human primates have made major contributions to our understanding of the brain and will continue to be an important, if small, part of neuroscience research, according to a recent review published in the British medical journal, The Lancet.

Pain Free Without Numbness — Substance Combination With Chili Peppers:

A dentist’s injection typically causes numbness for several hours. This experience could soon be history. Now, Clifford Woolf, professor at Harvard Medical School and the Massachusetts General Hospital, Boston, USA, and his colleagues have developed a combination of two agents which is able to specifically block pain without producing numbness or motor paralysis. The substance is composed of a normally inactive derivative of the local anesthetic lidocaine, called QX314, and capsaicin, the pain-producing substance in chili peppers.

Culture Affects How Teen Girls See Sexual Harassment:

Teenage girls of all ethnic and socioeconomic backgrounds still experience sexism and sexual harassment — but cultural factors may control whether they perceive sexism as an environmental problem or as evidence of their own shortcomings.

Monarch Butterflies Help Explain Why Parasites Harm Hosts:

It’s a paradox that has confounded evolutionary biologists since Charles Darwin published On the Origin of Species in 1859: Since parasites depend on their hosts for survival, why do they harm them? A new University of Georgia and Emory University study of monarch butterflies and the microscopic parasites that hitch a ride on them finds that the parasites strike a middle ground between the benefits gained by reproducing rapidly and the costs to their hosts. The study, published in the early online edition of the journal Proceedings of the National Academy of Sciences, provides the first empirical evidence in a natural system of what’s called the “trade-off hypothesis.”

Recipe For Energy Saving Unravelled In Migratory Birds:

Pointed wings together with carrying less weight per wing area and avoidance of high winds and atmospheric turbulence save a bird loads of energy during migration. This has been shown for the first time in free-flying wild birds by researchers at Princeton University, the University of Montana, and the German Max Planck Institute for Ornithology. They state that climate change might have a critical impact on small migrants’ energy budgets if it causes higher winds and atmospheric instability as predicted.

Warming Climate Is Changing Life On Global Scale, Says New Study:

A vast array of physical and biological systems across the earth are being affected by warming temperatures caused by humans, says a new analysis of information not previously assembled all in one spot. The effects on living things include earlier leafing of trees and plants over many regions; movements of species to higher latitudes and altitudes in the northern hemisphere; changes in bird migrations in Europe, North America and Australia; and shifting of the oceans’ plankton and fish from cold- to warm-adapted communities.

New Insights Into The Dynamics Of The Brain’s Cortex:

Using mathematics and a computer model of brain activity, Roberto Fernández Galán, Ph.D., an assistant professor of neurosciences at Case Western Reserve University School of Medicine, has shown a direct link between activity in the cortex and the microscopic structure of this neuronal network.

Endocrine Disruptors In Common Plastics Linked To Obesity Risk:

Exposure during development either in the womb or during infancy to chemicals used to make products such as baby bottles, the lining of food tins and some plastic food wraps and containers, may contribute to the development of obesity, according to new research presented at the European Congress on Obesity.

Female Sex Offenders Often Have Mental Problems:

Women who commit sexual offences are just as likely to have mental problems or drug addictions as other violent female criminals. This according to the largest study ever conducted of women convicted of sexual offences in Sweden.

Girls, Young Women Can Cut Risk Of Early Breast Cancer Through Regular Exercise:

Mothers, here’s another reason to encourage your daughters to be physically active: Girls and young women who exercise regularly between the ages of 12 and 35 have a substantially lower risk of breast cancer before menopause compared to those who are less active, new research shows.

Bears And Hibernation: New Insights Into Metabolism In Extreme Conditions:

Due to their ability to produce a potent inhibitor of protein degradation, hibernating bears do not lose muscle mass after long periods of hibernation. This is the main conclusion of the study directed by Professor Josep M. Argilés and co-written by Francisco J. López-Soriano, Gemma Fuster, Sílvia Busquets and Vanessa Almendro of the Cancer Research Group at the Biochemistry and Molecular Biology Department of the University of Barcelona (UB).

Rapid, Dramatic ‘Reverse Evolution’ Documented In Tiny Fish Species:

Evolution is supposed to inch forward over eons, but sometimes, at least in the case of a little fish called the threespine stickleback, the process can go in relative warp-speed reverse, according to a study led by researchers at Fred Hutchinson Cancer Research Center and published online ahead of print in the May 20 issue of Current Biology.

Mice Can Do Without Humans’ Most Treasured Genes:

The mouse is a stalwart stand-in for humans in medical research, thanks to genomes that are 85 percent identical. But identical genes may behave differently in mouse and man, a study by University of Michigan evolutionary biologists Ben-Yang Liao and Jianzhi Zhang reveals.

Wild Three-Toed Sloths Sleep 6 Hours Less Per Day Than Captive Sloths, First Electrophysical Recording Shows:

In the first experiment to record the electrophysiology of sleep in a wild animal, three-toed sloths carrying miniature electroencephalogram recorders slept 9.63 hours per day–6 hours less than captive sloths did, reports an international team of researchers working on the Smithsonian Tropical Research Institute’s Barro Colorado Island in Panama.

Educated People In US Living Longer, Less Educated Have Unchanged Death Rate:

A new study finds a gap in overall death rates between Americans with less than high school education and college graduates increased rapidly from 1993 to 2001. The study says the widening gap was due to significant decreases in mortality from all causes, heart disease, cancer, stroke, and other conditions, in the most educated while death rates among the least educated remained relatively unchanged. The study is the first to examine recent trends in socioeconomic inequalities in mortality from all causes as well as several leading causes of death in the United States using national individual-level socioeconomic measures.

Weird Shrimp Has Astounding Vision:

A Swiss marine biologist and an Australian quantum physicist have found that a species of shrimp from the Great Barrier Reef, Australia, can see a world invisible to all other animals. Dr Sonja Kleinlogel and Professor Andrew White have shown that mantis shrimp not only have the ability to see colours from the ultraviolet through to the infrared, but have optimal polarisation vision — a first for any animal and a capability that humanity has only achieved in the last decade using fast computer technology.

Human Vision Inadequate For Research On Bird Vision:

The most attractive male birds attract more females and as a result are most successful in terms of reproduction. This is the starting point of many studies looking for factors that influence sexual selection in birds. However, is it reasonable to assume that birds see what we see? In a study published in the latest issue of American Naturalist, Uppsala researchers show that our human vision is not an adequate instrument.

Put The Trees In The Ground: A Fix For The Global Carbon Dioxide Problem?:

Of the current global environmental problems, the excessive release of carbon dioxide from the combustion of fossil fuels and the related global warming is one of the most pressing. In an essay in the journal ChemSusChem , Fritz Scholz and Ulrich Hasse from the University of Greifswald introduce a possible approach to a solution: deliberately planted forests bind the CO2 through photosynthesis and are then removed from the global CO2 cycle by burial. “For the first time, humankind will give something back to nature that we have taken away before,” says Scholz.

What’s The Difference Between A Human And A Fruit Fly?:

Fruit flies are dramatically different from humans not in their number of genes, but in the number of protein interactions in their bodies, according to scientists who have developed a new way of estimating the total number of interactions between proteins in any organism.

Teen Helps Design Classroom DNA Experiments Using Common Food Dyes:

Agarose gel electrophoresis? Most teenagers wouldn’t have a clue what this scientific term means, but middle school student Andrew Trigiano knows the protocol inside and out. When Andrew was 12, his father Robert Trigiano, a professor at the University of Tennessee, was looking for an interesting science project for his son. Setting out to compare differences in popular brands of Easter egg dyes, Trigiano’s project soon grew into a full-blown scientific study and set of replicable classroom experiments.

When It Comes To Living Longer, It’s Better To Go Hungry Than Go Running, Mouse Study Suggests:

A study investigating aging in mice has found that hormonal changes that occur when mice eat significantly less may help explain an already established phenomenon: a low calorie diet can extend the lifespan of rodents, a benefit that even regular exercise does not achieve.

There are 57 articles this week in PLoS ONE – look around for yourself, these are my own picks:
The Secret World of Shrimps: Polarisation Vision at Its Best:

Animal vision spans a great range of complexity, with systems evolving to detect variations in light intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. Polarisation is fully measured via Stokes’ parameters–obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes’ parameters: here we show that the crustacean Gonodactylus smithii measures the exact components required. This vision provides optimal contrast-enhancement and precise determination of polarisation with no confusion states or neutral points–significant advantages. Linear and circular polarisation each give partial information about the polarisation of light–but the combination of the two, as we will show here, results in optimal polarisation vision. We suggest that linear and circular polarisation vision not be regarded as different modalities, since both are necessary for optimal polarisation vision; their combination renders polarisation vision independent of strongly linearly or circularly polarised features in the animal’s environment.

Sticky Gecko Feet: The Role of Temperature and Humidity:

Gecko adhesion is expected to be temperature insensitive over the range of temperatures typically experienced by geckos. Previous work is limited and equivocal on whether this expectation holds. We tested the temperature dependence of adhesion in Tokay and Day geckos and found that clinging ability at 12°C was nearly double the clinging ability at 32°C. However, rather than confirming a simple temperature effect, our data reveal a complex interaction between temperature and humidity that can drive differences in adhesion by as much as two-fold. Our findings have important implications for inferences about the mechanisms underlying the exceptional clinging capabilities of geckos, including whether performance of free-ranging animals is based solely on a dry adhesive model. An understanding of the relative contributions of van der Waals interactions and how humidity and temperature variation affects clinging capacities will be required to test hypotheses about the evolution of gecko toepads and is relevant to the design and manufacture of synthetic mimics.

Rival Male Relatedness Does Not Affect Ejaculate Allocation as Predicted by Sperm Competition Theory:

When females are sexually promiscuous, the intensity of sperm competition for males depends on how many partners females mate with. To maximize fitness, males should adjust their copulatory investment in relation to this intensity. However, fitness costs associated with sperm competition may not only depend on how many males a female has mated with, but also how related rival males are. According to theoretical predictions, males should adjust their copulatory investment in response to the relatedness of their male rival, and transfer more sperm to females that have first mated with a non-sibling male than females that have mated to a related male. Here, for the first time, we empirically test this theory using the Australian field cricket Teleogryllus oceanicus. We expose male crickets to sperm competition from either a full sibling or non-sibling male, by using both the presence of a rival male and the rival male’s actual competing ejaculate as cues. Contrary to predictions, we find that males do not adjust ejaculates in response to the relatedness of their male rival. Instead, males with both full-sibling and non-sibling rivals allocate sperm of similar quality to females. This lack of kin biased behaviour is independent of any potentially confounding effect of strong competition between close relatives; kin biased behaviour was absent irrespective of whether males were raised in full sibling or mixed relatedness groups.

Pointed Wings, Low Wingloading and Calm Air Reduce Migratory Flight Costs in Songbirds:

Migratory bird, bat and insect species tend to have more pointed wings than non-migrants. Pointed wings and low wingloading, or body mass divided by wing area, are thought to reduce energy consumption during long-distance flight, but these hypotheses have never been directly tested. Furthermore, it is not clear how the atmospheric conditions migrants encounter while aloft affect their energy use; without such information, we cannot accurately predict migratory species’ response(s) to climate change. Here, we measured the heart rates of 15 free-flying Swainson’s Thrushes (Catharus ustulatus) during migratory flight. Heart rate, and therefore rate of energy expenditure, was positively associated with individual variation in wingtip roundedness and wingloading throughout the flights. During the cruise phase of the flights, heart rate was also positively associated with wind speed but not wind direction, and negatively but not significantly associated with large-scale atmospheric stability. High winds and low atmospheric stability are both indicative of the presence of turbulent eddies, suggesting that birds may be using more energy when atmospheric turbulence is high. We therefore suggest that pointed wingtips, low wingloading and avoidance of high winds and turbulence reduce flight costs for small birds during migration, and that climate change may have the strongest effects on migrants’ in-flight energy use if it affects the frequency and/or severity of high winds and atmospheric instability.

Continue reading →

College Student Sleep Patterns Could Be Detrimental:

A Central Michigan University study has determined that many college students have sleep patterns that could have detrimental effects on their daily performance.

When Following The Leader Can Lead Into The Jaws Of Death:

For animals that live in social groups, and that includes humans, blindly following a leader could place them in danger. To avoid this, animals have developed simple but effective behaviour to follow where at least a few of them dare to tread — rather than follow a single group member. This pattern of behaviour reduces the risk of imitating maverick behaviour of an individual as the group recognise that consensus is better than following someone that goes it alone.

Ancient Protein Offers Clues To Killer Condition:

More than 600 million years of evolution has taken two unlikely distant cousins — turkeys and scallops – down very different physical paths from a common ancestor. But University of Leeds researchers have found that a motor protein, myosin 2, remains structurally identical in both creatures.

It Started With A Squeak: Moonlight Serenade Helps Lemurs Pick Mates Of The Right Species:

Lonely hearts columns testify that finding a partner can be hard enough, but at least most human beings can be fairly certain that when we do we have got one of the right species. Things aren’t so simple for all animals. Some Malagasy mouse lemurs are so similar that picking a mate of the right species, especially at night time in a tropical forest, might seem like a matter of pot luck. However, new research in BioMed Central’s journal BMC Biology has shown that our desperately cute distant cousins use vocalisations to pick up a partner of the right species.

Psychological Stress Linked To Overeating, Monkey Study Shows:

Researchers at the Yerkes National Primate Research Center, Emory University, have found socially subordinate female rhesus macaques over consume calorie-rich foods at a significantly higher level than do dominant females.

‘Shaquille O’Neal’ Of Bacteria Big Enough To See With Naked Eye:

Cornell researchers are studying bacterium big enough to see — the Shaquille O’Neal of bacteria. Well, perhaps not quite Shaquille O’Neal. But it is Shaq-teria. The secret to an unusual bacterium’s massive size — it’s the size of a grain of salt, or a million times bigger than E. coli bacteria, and big enough to see with the naked eye — may be found in its ability to copy its genome tens of thousands of times.

Sniffing Dogs Detect Feces To Help Monitor And Protect Threatened Animals In Brazil:

It’s a tough job, but somebody, or at least some dogs, have to do it. In the Cerrado region of Brazil, four dogs trained to detect animal feces by scent are helping researchers monitor rare and threatened wildlife such as jaguar, tapir, giant anteater and maned wolf in and around Emas National Park, a protected area with the largest concentration of threatened species in Brazil.

Architecture For Fundamental Processes Of Life Discovered:

A team of Canadian researchers has completed a massive survey of the network of protein complexes that orchestrate the fundamental processes of life. In the online edition of the journal Science, researchers from the Université de Montréal describe protein complexes and networks of complexes never before observed — including two implicated in the normal mechanisms by which cells divide and proliferate and another that controls recycling of the molecular building blocks of life called autophagy.

Female Concave-eared Frogs Draw Mates With Ultrasonic Calls:

Most female frogs don’t call; most lack or have only rudimentary vocal cords. A typical female selects a mate from a chorus of males and then –silently — signals her beau. But the female concave-eared torrent frog, Odorrana tormota, has a more direct method of declaring her interest: She emits a high-pitched chirp that to the human ear sounds like that of a bird.

Math Plus ‘Geeky’ Images Equals Deterred Students:

Images of maths ‘geeks’ stop people from studying mathematics or using it in later life, shows new research.

Kids Think Eyeglasses Make Other Kids Look Smart:

Young children tend to think that other kids with glasses look smarter than kids who don’t wear glasses, according to a new study.

Genetics Confirm Oral Traditions Of Druze In Israel:

DNA analysis of residents of Druze villages in Israel suggests these ancient religious communities offer a genetic snapshot of the Near East as it was several thousands of years ago.

Worms Triple Sperm Transfer When Paternity Is At Risk:

Scientists used to think that hermaphrodites, due to their low position in the evolutionary scale, did not have sufficiently developed sensory systems to assess the “quality” of their mates. A new work has shown, however, that earthworms are able to detect the competition by fertilising the eggs that is going to find its sperm, tripling its volume when there is rivalry. This ability is even more refined as they are able to transfer more sperm to more fertile partners.

Fish Diet To Avoid Fights With Slightly Larger Rivals:

People diet to look more attractive. Fish diet to avoid being beaten up, thrown out of their social group – and getting eaten as a result.

What Does The Label On Your Chicken Really Mean?:

Buying chicken these days is not like it used to be. With labels like “100 percent natural,” “organic,” “grain-fed,” and “free range,” many consumers don’t really know what they’re buying.

The Case of Deborah Rice: Who Is the Environmental Protection Agency Protecting?:

For researchers who operate at the intersection of basic biology and toxicology, following the data where they take you–as any good scientist would–carries the risk that you will be publicly attacked as a crank, charged with scientific misconduct, or removed from a government scientific review panel. Such a fate may seem unthinkable to those involved in primary research, but it has increasingly become the norm for toxicologists and environmental investigators. If you find evidence that a compound worth billions of dollars to its manufacturer poses a public health risk, you will almost certainly find yourself in the middle of a contentious battle that has little to do with scientific truth.

Retail Sales of Alcohol and the Risk of Being a Victim of Assault:

The relationship between alcohol sales, alcohol consumption patterns, and levels of violence is well established. In a meta-analysis of data from seven countries, Jason Bond and colleagues estimated that the fraction of violence-related injuries attributable to alcohol is between 28% and 43% [1]. There is a stronger link between alcohol impairment and being a victim of violence than between alcohol impairment and suffering from accidental injuries.

Communicating the Results of Clinical Research to Participants: Attitudes, Practices, and Future Directions:

Recent commentaries advocate routinely offering study results to research participants [1,2]. However, debate continues over the scope and limits of investigators’ responsibilities in this regard. A 2006 review identified 30 national and international policies and guidelines concerning the duty to return research results [3], of which 21 were published in the last decade. Worldwide interest in this complex issue will likely continue to rise in light of the increasing relevance of the results of biomedical research to participants’ health and well-being.

Dying Bats In The Northeast U.S. Remain A Mystery:

Investigations continue into the cause of a mysterious illness that has resulted in the deaths of thousands of bats since March 2008. At more than 25 caves and mines in the northeastern U.S., bats exhibiting a condition now referred to as “white-nosed syndrome” have been dying.

‘Early Birds’ Adapt To Climate Change:

Individual birds can adjust their behaviour to take climate change in their stride, according to a study by scientists from the University of Oxford. A study of the great tit (Parus major) population in Wytham Woods, near Oxford, has shown that the birds are now laying their eggs, on average, two weeks earlier than half a century ago. The change in their behaviour enables them to make the most of seasonal food: a bonanza of caterpillars that now also occurs around two weeks earlier due to warmer spring temperatures.

Intensive Farming Is Fine For Birds And Bees, Says Report:

Eco-friendly plant and animal life have been thriving in intensively managed cereal farms alongside increasing crop yields, according to the first study of its kind.

Endangered Species Up The Risk Of Extinction For Other Species In Ecological Community:

An endangered species of flora or fauna ups the risk of the extinction of the other species in its ecological community. Trophically unique species are more vulnerable for cascading extinction, according to studies of a team of theoretical biologists active at Linköping University and the University of Sheffield.

Eel Fishing Multiplies The Accidental Capture Of Other Fish By Eight:

In the Ebro River delta, the fishing of elver (Anguilla anguilla) leads to the accidental capture of other fish species, with the capture of one ton of elver possibly resulting in the capture of up to 8.2 tons of accompanying species. Researchers from the Institute for Agro-Food Research and Technology (IRTA), who have assessed the effects of this method of fishing and identified the most fragile species, propose improvements in current methodologies.

Young People Are Intentionally Drinking And Taking Drugs For Better Sex, European Survey Finds:

Teenagers and young adults across Europe drink and take drugs as part of deliberate sexual strategies. New findings reveal that a third of 16-35 year old males and a quarter of females surveyed are drinking alcohol to increase their chances of sex, while cocaine, ecstasy and cannabis are intentionally used to enhance sexual arousal or prolong sex.

How ‘Horse Tranquilizer’ Stops Depression:

Researchers have shown exactly how the anaesthetic ketamine helps depression with images that show the orbitofrontal cortex – the part of the brain that is overactive in depression – being ‘switched off’. Ketamine, an anaesthetic that is popular with doctors on the battlefield and also with vets because it allows a degree of awareness without pain, is a new hope for the treatment of depression – but the minute-by-minute images produced by Professor Bill Deakin and his team show how the drug achieves this in an unexpected way.

Surprising Discovery: Multicellular Response Is ‘All For One’:

Real or perceived threats can trigger the well-known “fight or flight response” in humans and other animals. Adrenaline flows, and the stressed individual’s heart pumps faster, the muscles work harder, the brain sharpens and non-essential systems shut down. The whole organism responds in concert in order to survive. At the molecular level, it has been widely assumed that, in single-celled organisms, each cell perceives its environment — and responds to stress conditions — individually, each on its own to protect itself. Likewise, it had been thought that cells in multicellular organisms respond the same way, but a new study by scientists at Northwestern University reports otherwise.

Federal Polar Bear Research Critically Flawed, Forecasting Expert Asserts:

Research done by the U.S. Department of the Interior to determine if global warming threatens the polar bear population is so flawed that it cannot be used to justify listing the polar bear as an endangered species, according to a study being published later this year in Interfaces, a journal of the Institute for Operations Research and the Management Sciences.

What’s Bugging Locusts? It Could Be They’re Hungry — For Each Other:

Since ancient times, locust plagues have been viewed as one of the most spectacular events in nature. In seemingly spontaneous fashion, as many as 10 billion critters can suddenly swarm the air and carpet the ground, blazing destructive paths that bring starvation and economic ruin. What makes them do it? A team of scientists led by Iain Couzin of Princeton University and including colleagues at the University of Oxford and the University of Sydney believes it may finally have an answer to this enduring mystery.

Koalas Under Threat From Climate Change:

New research shows increased temperatures and carbon dioxide levels are a threat to the Australian national icon, the koala.

PLoS ONE paper The Herbicide Atrazine Activates Endocrine Gene Networks via Non-Steroidal NR5A Nuclear Receptors in Fish and Mammalian Cells will be one of the topics covered by Science Friday on NPR tomorrow – tune in if you can, or wait until the podcast is posted on the site later tomorrow night:

Researchers report that the common weedkiller atrazine may be able to disrupt hormonal signaling in humans. The herbicide is the second-most-applied weedkiller in the United States, with uses from suburban lawns to agricultural production of corn and sorghum.
In recent years, atrazine has been suspected of playing a role in sexual abnormalities in fish, frogs, and other aquatic organisms. The chemical has been banned in Europe, but is still widely used in the U.S. Now, writing in the journal PLOS One, researchers report that the chemical appears to affect two different genes in human placental cells. We’ll talk with one of the authors of the study about the work and what it means.

Why Face Symmetry Is Sexy Across Cultures And Species:

In humans, faces are an important source of social information. One property of faces that is rapidly noticed is attractiveness. Research has highlighted symmetry and sexual dimorphism (how masculine or feminine a face is) as important variables that determine a face’s attractiveness.

Platypus Genome Explains Animal’s Peculiar Features; Holds Clues To Evolution Of Mammals:

The duck-billed platypus: part bird, part reptile, part mammal — and the genome to prove it.

Biodiversity: It’s In The Water:

What if hydrology is more important for predicting biodiversity than biology? New research challenges current thinking about biodiversity and opens up new avenues for predicting how climate change or human activity may affect biodiversity patterns.

When Bears Steal Human Food, Mom’s Not To Blame:

Researchers from the Wildlife Conservation Society (WCS) found that the black bears that become habituated to human food and garbage may not be learning these behaviors exclusively from their mothers, as widely assumed. Bears that steal human food sources are just as likely to form these habits on their own or pick them up from unrelated, “bad influence” bears.

Mathematics Simplifies Sleep Monitoring:

A UQ researcher has created a new way to measure breathing patterns in sleeping infants which may also work for adults.

It Might Be True That ‘Men Marry Their Mothers’:

Whether a young man’s mother earned a college degree and whether she worked outside the home while he was growing up seems to have an effect years later when he considers his ideal wife, according to a study by University of Iowa sociologist Christine Whelan.

Does The Brain Control Muscles Or Movements?:

One of the major scientific questions about the brain is how it can translate the simple intent to perform an action–say, reach for a glass–into the dynamic, coordinated symphony of muscle movements required for that action. The neural instructions for such actions originate in the brain’s primary motor cortex, and the puzzle has been whether the neurons in this region encode the details of individual muscle activities or the high-level commands that govern kinetics–the direction and velocity of desired movements.

Killer Competition: Neurons Duke It Out For Survival:

The developing nervous system makes far more nerve cells than are needed to ensure target organs and tissues are properly connected to the nervous system. As nerves connect to target organs, they somehow compete with each other resulting in some living and some dying. Now, using a combination of computer modeling and molecular biology, neuroscientists at Johns Hopkins have discovered how the target tissue helps newly connected peripheral nerve cells strengthen their connections and kill neighboring nerves. The study was published in the April 18th issue of Science.

There are 56 new articles published in PLoS ONE this week and it was hard to make the picks as this seems to be a very, very good week with lots of cool papers. Here are some of the highlights – please post ratings, notes and comments on the papers, write blog posts and send trackbacks:
Seed Dispersal and Establishment of Endangered Plants on Oceanic Islands: The Janzen-Connell Model, and the Use of Ecological Analogues:

The Janzen-Connell model states that plant-specific natural enemies may have a disproportionately large negative effect on progeny close to maternal trees. The majority of experimental and theoretical studies addressing the Janzen-Connell model have explored how it can explain existing patterns of species diversity in tropical mainland areas. Very few studies have investigated how the model’s predictions apply to isolated oceanic islands, or to the conservation management of endangered plants. Here, we provide the first experimental investigation of the predictions of the Janzen-Connell model on an oceanic island, in a conservation context. In addition, we experimentally evaluate the use of ecological analogue animals to resurrect the functional component of extinct frugivores that could have dispersed seeds away from maternal trees. In Mauritius, we investigated seed germination and seedling survival patterns of the critically endangered endemic plant Syzygium mamillatum (Myrtaceae) in relation to proximity to maternal trees. We found strong negative effects of proximity to maternal trees on growth and survival of seedlings. We successfully used giant Aldabran tortoises as ecological analogues for extinct Mauritian frugivores. Effects of gut-passage were negative at the seed germination stage, but seedlings from gut-passed seeds grew taller, had more leaves, and suffered less damage from natural enemies than any of the other seedlings. We provide the first experimental evidence of a distance-dependent Janzen-Connell effect on an oceanic island. Our results potentially have serious implications for the conservation management of rare plant species on oceanic islands, which harbour a disproportionately large fraction of the world’s endemic and endangered plants. Furthermore, in contrast to recent controversy about the use of non-indigenous extant megafauna for re-wilding projects in North America and elsewhere, we argue that Mauritius and other oceanic islands are ideal study systems in which to empirically explore the use of ecological analogue species in restoration ecology.

The Druze: A Population Genetic Refugium of the Near East:

Phylogenetic mitochondrial DNA haplogroups are highly partitioned across global geographic regions. A unique exception is the X haplogroup, which has a widespread global distribution without major regions of distinct localization. We have examined mitochondrial DNA sequence variation together with Y-chromosome-based haplogroup structure among the Druze, a religious minority with a unique socio-demographic history residing in the Near East. We observed a striking overall pattern of heterogeneous parental origins, consistent with Druze oral tradition, together with both a high frequency and a high diversity of the mitochondrial DNA (mtDNA) X haplogroup within a confined regional subpopulation. Furthermore demographic modeling indicated low migration rates with nearby populations. These findings were enabled through the use of a paternal kindred based sampling approach, and suggest that the Galilee Druze represent a population isolate, and that the combination of a high frequency and diversity of the mtDNA X haplogroup signifies a phylogenetic refugium, providing a sample snapshot of the genetic landscape of the Near East prior to the modern age.

Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis:

Uncertainty persists over the environmental effects of genetically-engineered crops that produce the insecticidal Cry proteins of Bacillus thuringiensis (Bt). We performed meta-analyses on a modified public database to synthesize current knowledge about the effects of Bt cotton, maize and potato on the abundance and interactions of arthropod non-target functional guilds. We compared the abundance of predators, parasitoids, omnivores, detritivores and herbivores under scenarios in which neither, only the non-Bt crops, or both Bt and non-Bt crops received insecticide treatments. Predators were less abundant in Bt cotton compared to unsprayed non-Bt controls. As expected, fewer specialist parasitoids of the target pest occurred in Bt maize fields compared to unsprayed non-Bt controls, but no significant reduction was detected for other parasitoids. Numbers of predators and herbivores were higher in Bt crops compared to sprayed non-Bt controls, and type of insecticide influenced the magnitude of the difference. Omnivores and detritivores were more abundant in insecticide-treated controls and for the latter guild this was associated with reductions of their predators in sprayed non-Bt maize. No differences in abundance were found when both Bt and non-Bt crops were sprayed. Predator-to-prey ratios were unchanged by either Bt crops or the use of insecticides; ratios were higher in Bt maize relative to the sprayed non-Bt control. Overall, we find no uniform effects of Bt cotton, maize and potato on the functional guilds of non-target arthropods. Use of and type of insecticides influenced the magnitude and direction of effects; insecticde effects were much larger than those of Bt crops. These meta-analyses underscore the importance of using controls not only to isolate the effects of a Bt crop per se but also to reflect the replacement of existing agricultural practices. Results will provide researchers with information to design more robust experiments and will inform the decisions of diverse stakeholders regarding the safety of transgenic insecticidal crops.

The Aerodynamic Signature of Running Spiders:

Many predators display two foraging modes, an ambush strategy and a cruising mode. These foraging strategies have been classically studied in energetic, biomechanical and ecological terms, without considering the role of signals produced by predators and perceived by prey. Wolf spiders are a typical example; they hunt in leaf litter either using an ambush strategy or by moving at high speed, taking over unwary prey. Air flow upstream of running spiders is a source of information for escaping prey, such as crickets and cockroaches. However, air displacement by running arthropods has not been previously examined. Here we show, using digital particle image velocimetry, that running spiders are highly conspicuous aerodynamically, due to substantial air displacement detectable up to several centimetres in front of them. This study explains the bimodal distribution of spider’s foraging modes in terms of sensory ecology and is consistent with the escape distances and speeds of cricket prey. These findings may be relevant to the large and diverse array of arthropod prey-predator interactions in leaf litter.

Is Exercise Protective Against Influenza-Associated Mortality?:

Little is known about the effect of physical exercise on influenza-associated mortality. We collected information about exercise habits and other lifestyles, and socioeconomic and demographic status, the underlying cause of death of 24,656 adults (21% aged 30-64, 79% aged 65 or above) who died in 1998 in Hong Kong, and the weekly proportion of specimens positive for influenza A (H3N1 and H1N1) and B isolations during the same period. We assessed the excess risks (ER) of influenza-associated mortality due to all-natural causes, cardiovascular diseases, or respiratory disease among different levels of exercise: never/seldom (less than once per month), low/moderate (once per month to three times per week), and frequent (four times or more per week) by Poisson regression. We also assessed the differences in ER between exercise groups by case-only logistic regression. For all the mortality outcomes under study in relation to each 10% increase in weekly proportion of specimens positive for influenza A+B, never/seldom exercise (as reference) was associated with 5.8% to 8.5% excess risks (ER) of mortality (P<0.0001), while low/moderate exercise was associated with ER which were 4.2% to 6.4% lower than those of the reference (P<0.001 for all-natural causes; P = 0.001 for cardiovascular; and P = 0.07 for respiratory mortality). Frequent exercise was not different from the reference (change in ER −0.8% to 1.7%, P = 0.30 to 0.73). When compared with never or seldom exercise, exercising at low to moderate frequency is beneficial with lower influenza-associated mortality.

Symmetry Is Related to Sexual Dimorphism in Faces: Data Across Culture and Species:

Many animals both display and assess multiple signals. Two prominently studied traits are symmetry and sexual dimorphism, which, for many animals, are proposed cues to heritable fitness benefits. These traits are associated with other potential benefits, such as fertility. In humans, the face has been extensively studied in terms of attractiveness. Faces have the potential to be advertisements of mate quality and both symmetry and sexual dimorphism have been linked to the attractiveness of human face shape. Here we show that measurements of symmetry and sexual dimorphism from faces are related in humans, both in Europeans and African hunter-gatherers, and in a non-human primate. Using human judges, symmetry measurements were also related to perceived sexual dimorphism. In all samples, symmetric males had more masculine facial proportions and symmetric females had more feminine facial proportions. Our findings support the claim that sexual dimorphism and symmetry in faces are signals advertising quality by providing evidence that there must be a biological mechanism linking the two traits during development. Such data also suggests that the signalling properties of faces are universal across human populations and are potentially phylogenetically old in primates.

Multigene Phylogeny of Choanozoa and the Origin of Animals:

Animals are evolutionarily related to fungi and to the predominantly unicellular protozoan phylum Choanozoa, together known as opisthokonts. To establish the sequence of events when animals evolved from unicellular ancestors, and understand those key evolutionary transitions, we need to establish which choanozoans are most closely related to animals and also the evolutionary position of each choanozoan group within the opisthokont phylogenetic tree. Here we focus on Ministeria vibrans, a minute bacteria-eating cell with slender radiating tentacles. Single-gene trees suggested that it is either the closest unicellular relative of animals or else sister to choanoflagellates, traditionally considered likely animal ancestors. Sequencing thousands of Ministeria protein genes now reveals about 14 with domains of key significance for animal cell biology, including several previously unknown from deeply diverging Choanozoa, e.g. domains involved in hedgehog, Notch and tyrosine kinase signaling or cell adhesion (cadherin). Phylogenetic trees using 78 proteins show that Ministeria is not sister to animals or choanoflagellates (themselves sisters to animals), but to Capsaspora, another protozoan with thread-like (filose) tentacles. The Ministeria/Capsaspora clade (new class Filasterea) is sister to animals and choanoflagellates, these three groups forming a novel clade (filozoa) whose ancestor presumably evolved filose tentacles well before they aggregated as a periciliary collar in the choanoflagellate/sponge common ancestor. Our trees show ichthyosporean choanozoans as sisters to filozoa; a fusion between ubiquitin and ribosomal small subunit S30 protein genes unifies all holozoa (filozoa plus Ichthyosporea), being absent in earlier branching eukaryotes. Thus, several successive evolutionary innovations occurred among their unicellular closest relatives prior to the origin of the multicellular body-plan of animals.

Species-Specific Diversity of a Fixed Motor Pattern: The Electric Organ Discharge of Gymnotus:

Understanding fixed motor pattern diversity across related species provides a window for exploring the evolution of their underlying neural mechanisms. The electric organ discharges of weakly electric fishes offer several advantages as paradigmatic models for investigating how a neural decision is transformed into a spatiotemporal pattern of action. Here, we compared the far fields, the near fields and the electromotive force patterns generated by three species of the pulse generating New World gymnotiform genus Gymnotus. We found a common pattern in electromotive force, with the far field and near field diversity determined by variations in amplitude, duration, and the degree of synchronization of the different components of the electric organ discharges. While the rostral regions of the three species generate similar profiles of electromotive force and local fields, most of the species-specific differences are generated in the main body and tail regions of the fish. This causes that the waveform of the field is highly site dependant in all the studied species. These findings support a hypothesis of the relative separation of the electrolocation and communication carriers. The presence of early head negative waves in the rostral region, a species-dependent early positive wave at the caudal region, and the different relationship between the late negative peak and the main positive peak suggest three points of lability in the evolution of the electrogenic system: a) the variously timed neuronal inputs to different groups of electrocytes; b) the appearance of both rostrally and caudally innervated electrocytes, and c) changes in the responsiveness of the electrocyte membrane.

Hung Out to Dry: Choice of Priority Ecoregions for Conserving Threatened Neotropical Anurans Depends on Life-History Traits (Related):

In the Neotropics, nearly 35% of amphibian species are threatened by habitat loss, habitat fragmentation, and habitat split; anuran species with different developmental modes respond to habitat disturbance in different ways. This entails broad-scale strategies for conserving biodiversity and advocates for the identification of high conservation-value regions that are significant in a global or continental context and that could underpin more detailed conservation assessments towards such areas. We identified key ecoregion sets for anuran conservation using an algorithm that favors complementarity (beta-diversity) among ecoregions. Using the WWF’s Wildfinder database, which encompasses 700 threatened anuran species in 119 Neotropical ecoregions, we separated species into those with aquatic larvae (AL) or terrestrial development (TD), as this life-history trait affects their response to habitat disturbance. The conservation target of 100% of species representation was attained with a set of 66 ecoregions. Among these, 30 were classified as priority both for species with AL and TD, 26 were priority exclusively for species with AL, and 10 for species with TD only. Priority ecoregions for both developmental modes are concentrated in the Andes and in Mesoamerica. Ecoregions important for conserving species with AL are widely distributed across the Neotropics. When anuran life histories were ignored, species with AL were always underrepresented in priority sets. The inclusion of anuran developmental modes in prioritization analyses resulted in more comprehensive coverage of priority ecoregions-especially those essential for species that require an aquatic habitat for their reproduction-when compared to usual analyses that do not consider this life-history trait. This is the first appraisal of the most important regions for conservation of threatened Neotropical anurans. It is also a first endeavor including anuran life-history traits in priority area-selection for conservation, with a clear gain in comprehensiveness of the selection process.

Consistency of Financial Interest Disclosures in the Biomedical Literature: The Case of Coronary Stents:

Disclosure of authors’ financial interests has been proposed as a strategy for protecting the integrity of the biomedical literature. We examined whether authors’ financial interests were disclosed consistently in articles on coronary stents published in 2006. We searched PubMed for English-language articles published in 2006 that provided evidence or guidance regarding the use of coronary artery stents. We recorded article characteristics, including information about authors’ financial disclosures. The main outcome measures were the prevalence, nature, and consistency of financial disclosures. There were 746 articles, 2985 authors, and 135 journals in the database. Eighty-three percent of the articles did not contain disclosure statements for any author (including declarations of no interests). Only 6% of authors had an article with a disclosure statement. In comparisons between articles by the same author, the types of disagreement were as follows: no disclosure statements vs declarations of no interests (64%); specific disclosures vs no disclosure statements (34%); and specific disclosures vs declarations of no interests (2%). Among the 75 authors who disclosed at least 1 relationship with an organization, there were 2 cases (3%) in which the organization was disclosed in every article the author wrote. In the rare instances when financial interests were disclosed, they were not disclosed consistently, suggesting that there are problems with transparency in an area of the literature that has important implications for patient care. Our findings suggest that the inconsistencies we observed are due to both the policies of journals and the behavior of some authors.

Dinosaur Bones Reveal Ancient Bug Bites:

Paleontologists have long been perplexed by dinosaur fossils with missing pieces – sets of teeth without a jaw bone, bones that are pitted and grooved, even bones that are half gone. Now a Brigham Young University study identifies a culprit: ancient insects that munched on dinosaur bones.

Saving Frogs Before It’s Too Late:

With nearly one-third of amphibian species threatened with extinction worldwide, fueled in part by the widespread emergence of the deadly chytrid fungus, effective conservation efforts could not be more urgent. In a new article, Franco Andreone and his colleagues argue that one of the best places to focus these efforts is Madagascar, a global hotspot of amphibian diversity that shows no signs of amphibian declines–or traces of the chytrid fungus.

New Reason For Bee Hive Collapse: Ecologists Tease Out Private Lives Of Plants And Their Pollinators:

The quality of pollen a plant produces is closely tied to its sexual habits, ecologists have discovered. As well as helping explain the evolution of such intimate relationships between plants and pollinators, the study — one of the first of its kind and published online in the British Ecological Society’s journal Functional Ecology — also helps explain the recent dramatic decline in certain bumblebee species found in the shrinking areas of species-rich chalk grasslands and hay meadows across Northern Europe.

Female Jumping Spiders Find Ultraviolet B Rays ‘Sexy’:

A report publishing online on May 1st in the journal Current Biology, a publication of Cell Press, provides the first evidence of an animal using ultraviolet B (UVB) rays to communicate with other members of its species.

Animal Interaction Behind Cambrian Explosion? ‘Missing’ Ancestors Of Today’s Animals May Not Be Missing After All:

An event as simple as the world’s first bite may have sparked an ancient “explosion” of life 500 million years ago that led to the rise of the broad groups of animals that are still alive today.

Trouble In Paradise: Global Warming A Greater Danger To Tropical Species:

Polar bears fighting for survival in the face of a rapid decline of polar ice have made the Arctic a poster child for the negative effects of climate change. But new research shows that species living in the tropics likely face the greatest peril in a warmer world.

Birds Do It, Bees Do It, but Candida albicans Does It Differently:

The yeast Candida albicans lives an unnoticed and mostly harmless life as a member of our gut flora. However, mainly in an immunocompromised host, it can proliferate and cause severe, life-threatening infections. Within this normally mild-mannered, single-celled fungus beats the heart of a reproductive adventurer. For while it appears to be incapable of meiosis and therefore true sex, it engages in an unusual and offbeat alternative–after it mates, its progeny randomly cast off chromosomes to restore the diploid number, or something close to it. In a new study, Anja Forche, Richard Bennett, and colleagues show that this process generates significant genetic diversity, which is further amplified by recombination between homologous chromosomes, using a protein that is elsewhere used exclusively in meiosis.

The Challenge of Conserving Amphibian Megadiversity in Madagascar:

Frogs from Madagascar constitute one of the richest groups of amphibian fauna in the world, with currently 238 described species; caecilians and salamanders are absent [1]. Several frog radiations of the island are species-rich and parallel lemurs and tenrecs in their astonishing morphological and ecological diversity. According to the Global Amphibian Assessment (GAA), Madagascar ranks as the country with the 12th highest amphibian species richness [2,3] (see also http://www.globalamphibians.org), but this is likely an underestimate, because an additional 182 candidate species have been identified since [1]. Diversity is concentrated in rainforests and can locally reach over 100 species. Impressively, 100% of the autochthonous species and 88% of the genera are strictly endemic to Madagascar and its inshore islands [1]. Most of these species belong to two radiations of astonishing ecomorphological and reproductive diversity, the mantellids and the scaphiophrynine plus cophyline microhylids.

Roaring Bats: New Scientific Results Show Bats Emitting More Decibels Than A Rock Concert:

Researchers studying the echolocation behavior in bats have discovered that the diminutive flying mammals emit exceptionally loud sounds — louder than any known animal in air.

Young Songbirds Babble Before They Learn To Sing:

Young songbirds babble before they can mimic an adult’s song, much like their human counterparts. Now, in work that offers insights into how birds–and perhaps people–learn new behaviors, MIT scientists have found that immature and adult birdsongs are driven by two separate brain pathways, rather than one pathway that slowly matures.

Birds Can Tell If You Are Watching Them — Because They Are Watching You:

In humans, the eyes are said to be the ‘window to the soul’, conveying much about a person’s emotions and intentions. New research demonstrates for the first time that birds also respond to a human’s gaze.

Two Discoveries Add To Giant Earthworm Science In Northwest:

Native, possibly giant, earthworm science in the Pacific Northwest is advancing with the discovery of two new specimens from opposite sides of the interior Columbia River basin.

Plants Text Message Farmers When Thirsty:

Beginning this crop season, farmers will be able to receive text messages on their cell phones from their plants saying whether they are thirsty or not.

There are 49 new articles in PLoS ONE this week. Here are some titles I found interesting:
Echolocating Bats Cry Out Loud to Detect Their Prey:

Echolocating bats have successfully exploited a broad range of habitats and prey. Much research has demonstrated how time-frequency structure of echolocation calls of different species is adapted to acoustic constraints of habitats and foraging behaviors. However, the intensity of bat calls has been largely neglected although intensity is a key factor determining echolocation range and interactions with other bats and prey. Differences in detection range, in turn, are thought to constitute a mechanism promoting resource partitioning among bats, which might be particularly important for the species-rich bat assemblages in the tropics. Here we present data on emitted intensities for 11 species from 5 families of insectivorous bats from Panamá hunting in open or background cluttered space or over water. We recorded all bats in their natural habitat in the field using a multi-microphone array coupled with photographic methods to assess the bats’ position in space to estimate emitted call intensities. All species emitted intense search signals. Output intensity was reduced when closing in on background by 4-7 dB per halving of distance. Source levels of open space and edge space foragers (Emballonuridae, Mormoopidae, Molossidae, and Vespertilionidae) ranged between 122-134 dB SPL. The two Noctilionidae species hunting over water emitted the loudest signals recorded so far for any bat with average source levels of ca. 137 dB SPL and maximum levels above 140 dB SPL. In spite of this ten-fold variation in emitted intensity, estimates indicated, surprisingly, that detection distances for prey varied far less; bats emitting the highest intensities also emitted the highest frequencies, which are severely attenuated in air. Thus, our results suggest that bats within a local assemblage compensate for frequency dependent attenuation by adjusting the emitted intensity to achieve comparable detection distances for prey across species. We conclude that for bats with similar hunting habits, prey detection range represents a unifying constraint on the emitted intensity largely independent of call shape, body size, and close phylogenetic relationships.

A New Concept for Medical Imaging Centered on Cellular Phone Technology:

According to World Health Organization reports, some three quarters of the world population does not have access to medical imaging. In addition, in developing countries over 50% of medical equipment that is available is not being used because it is too sophisticated or in disrepair or because the health personnel are not trained to use it. The goal of this study is to introduce and demonstrate the feasibility of a new concept in medical imaging that is centered on cellular phone technology and which may provide a solution to medical imaging in underserved areas. The new system replaces the conventional stand-alone medical imaging device with a new medical imaging system made of two independent components connected through cellular phone technology. The independent units are: a) a data acquisition device (DAD) at a remote patient site that is simple, with limited controls and no image display capability and b) an advanced image reconstruction and hardware control multiserver unit at a central site. The cellular phone technology transmits unprocessed raw data from the patient site DAD and receives and displays the processed image from the central site. (This is different from conventional telemedicine where the image reconstruction and control is at the patient site and telecommunication is used to transmit processed images from the patient site). The primary goal of this study is to demonstrate that the cellular phone technology can function in the proposed mode. The feasibility of the concept is demonstrated using a new frequency division multiplexing electrical impedance tomography system, which we have developed for dynamic medical imaging, as the medical imaging modality. The system is used to image through a cellular phone a simulation of breast cancer tumors in a medical imaging diagnostic mode and to image minimally invasive tissue ablation with irreversible electroporation in a medical imaging interventional mode.

Counting the Founders: The Matrilineal Genetic Ancestry of the Jewish Diaspora:

The history of the Jewish Diaspora dates back to the Assyrian and Babylonian conquests in the Levant, followed by complex demographic and migratory trajectories over the ensuing millennia which pose a serious challenge to unraveling population genetic patterns. Here we ask whether phylogenetic analysis, based on highly resolved mitochondrial DNA (mtDNA) phylogenies can discern among maternal ancestries of the Diaspora. Accordingly, 1,142 samples from 14 different non-Ashkenazi Jewish communities were analyzed. A list of complete mtDNA sequences was established for all variants present at high frequency in the communities studied, along with high-resolution genotyping of all samples. Unlike the previously reported pattern observed among Ashkenazi Jews, the numerically major portion of the non-Ashkenazi Jews, currently estimated at 5 million people and comprised of the Moroccan, Iraqi, Iranian and Iberian Exile Jewish communities showed no evidence for a narrow founder effect, which did however characterize the smaller and more remote Belmonte, Indian and the two Caucasus communities. The Indian and Ethiopian Jewish sample sets suggested local female introgression, while mtDNAs in all other communities studied belong to a well-characterized West Eurasian pool of maternal lineages. Absence of sub-Saharan African mtDNA lineages among the North African Jewish communities suggests negligible or low level of admixture with females of the host populations among whom the African haplogroup (Hg) L0-L3 sub-clades variants are common. In contrast, the North African and Iberian Exile Jewish communities show influence of putative Iberian admixture as documented by mtDNA Hg HV0 variants. These findings highlight striking differences in the demographic history of the widespread Jewish Diaspora.

A Pre-Hispanic Head:

This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS) compatible with the last pre-Hispanic period (1418-1491 AD, 95.4% probability). Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic and mercury) incompatible with life. There was no evidence for lead deposition in bone consistent with post-mortem accumulation of this toxic element in the hair. We propose that the high content of metals in hair was the result of metabolic activity of bacteria leading to metal complexation in extra cellular polymeric substances (EPS). This is a recognized protective mechanism for bacteria that thrive in toxic environments. This mechanism may account for the tissues preservation and gives a hint at soil composition where the head was presumably buried. Our results have implications for forensic toxicology which has, hitherto, relied on hair analyses as one means to reconstruct pre-mortem metabolism and for detecting toxic elements accumulated during life. Our finding also has implications for other archaeological specimens where similar circumstances may distort the results of toxicological studies.

An Analysis of the Abstracts Presented at the Annual Meetings of the Society for Neuroscience from 2001 to 2006:

Annual meeting abstracts published by scientific societies often contain rich arrays of information that can be computationally mined and distilled to elucidate the state and dynamics of the subject field. We extracted and processed abstract data from the Society for Neuroscience (SFN) annual meeting abstracts during the period 2001-2006 in order to gain an objective view of contemporary neuroscience. An important first step in the process was the application of data cleaning and disambiguation methods to construct a unified database, since the data were too noisy to be of full utility in the raw form initially available. Using natural language processing, text mining, and other data analysis techniques, we then examined the demographics and structure of the scientific collaboration network, the dynamics of the field over time, major research trends, and the structure of the sources of research funding. Some interesting findings include a high geographical concentration of neuroscience research in the north eastern United States, a surprisingly large transient population (66% of the authors appear in only one out of the six studied years), the central role played by the study of neurodegenerative disorders in the neuroscience community, and an apparent growth of behavioral/systems neuroscience with a corresponding shrinkage of cellular/molecular neuroscience over the six year period. The results from this work will prove useful for scientists, policy makers, and funding agencies seeking to gain a complete and unbiased picture of the community structure and body of knowledge encapsulated by a specific scientific domain.

Network ‘Small-World-Ness’: A Quantitative Method for Determining Canonical Network Equivalence:

Many technological, biological, social, and information networks fall into the broad class of ‘small-world’ networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction (‘small/not-small’) rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network’s small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model – the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified. We defined a precise measure of ‘small-world-ness’ S based on the trade off between high local clustering and short path length. A network is now deemed a ‘small-world’ if S>1 – an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process. We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing.

Of Mice and Men — Universality and Breakdown of Behavioral Organization:

Mental or cognitive brain functions, and the effect on them of abnormal psychiatric diseases, are difficult to approach through molecular biological techniques due to the lack of appropriate assay systems with objective measures. We therefore study laws of behavioral organization, specifically how resting and active periods are interwoven throughout daily life, using objective criteria, and first discover that identical laws hold both for healthy humans subject to the full complexity of daily life, and wild-type mice subject to maximum environmental constraints. We find that active period durations with physical activity counts successively above a predefined threshold, when rescaled with individual means, follow a universal stretched exponential (gamma-type) cumulative distribution, while resting period durations below the threshold obey a universal power-law cumulative distribution with identical parameter values for both of the mammalian species. Further, by analyzing the behavioral organization of mice with a circadian clock gene (Period2) eliminated, and humans suffering from major depressive disorders, we find significantly lower parameter values (power-law scaling exponents) for the resting period durations in both these cases. Such a universality and breakdown of the behavioral organization of mice and humans, revealed through objective measures, is expected to facilitate the understanding of the molecular basis of the pathophysiology of neurobehavioral diseases, including depression, and lay the foundations for formulating a range of neuropsychiatric behavioral disorder models.

Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei:

The Plio-Pleistocene hominin Paranthropus boisei had enormous, flat, thickly enameled cheek teeth, a robust cranium and mandible, and inferred massive, powerful chewing muscles. This specialized morphology, which earned P. boisei the nickname “Nutcracker Man”, suggests that this hominin could have consumed very mechanically challenging foods. It has been recently argued, however, that specialized hominin morphology may indicate adaptations for the consumption of occasional fallback foods rather than preferred resources. Dental microwear offers a potential means by which to test this hypothesis in that it reflects actual use rather than genetic adaptation. High microwear surface texture complexity and anisotropy in extant primates can be associated with the consumption of exceptionally hard and tough foods respectively. Here we present the first quantitative analysis of dental microwear for P. boisei. Seven specimens examined preserved unobscured antemortem molar microwear. These all show relatively low complexity and anisotropy values. This suggests that none of the individuals consumed especially hard or tough foods in the days before they died. The apparent discrepancy between microwear and functional anatomy is consistent with the idea that P. boisei presents a hominin example of Liem’s Paradox, wherein a highly derived morphology need not reflect a specialized diet.

Single-celled Bacterium Works 24/7:

Researchers at Washington University in St. Louis have gained the first detailed insight into the way circadian rhythms govern global gene expression in Cyanothece, a type of cyanobacterium (blue-green algae) known to cycle between photosynthesis during the day and nitrogen fixation at night.

How Birds Navigate: Research Team Is First To Model Photochemical Compass:

It has long been known that birds and many other animals including turtles, salamanders and lobsters, use the Earth’s magnetic field to navigate, but the nature of their global positioning systems (GPS) has not been completely understood. One school of thought hypothesizes that birds use magnetically-sensitive chemical reactions initiated by light (called chemical magnetoreception) to orient themselves, but no chemical reaction in the laboratory, until now, has been shown to respond to magnetic fields as weak as the Earth’s.

New Findings Challenge Conventional Ideas On Evolution Of Human Diet, Natural Selection:

New findings suggest that the ancient human “cousin” known as the “Nutcracker Man” wasn’t regularly eating anything like nuts after all.

Legless Lizard And Tiny Woodpecker Among New Species Discovered In Brazil:

Researchers discovered a legless lizard and a tiny woodpecker along with 12 other suspected new species in Brazil’s Cerrado, one of the world’s 34 biodiversity conservation hotspots.

Ancient Ecosystems Organized Much Like Our Own:

Similarities between half-billion-year-old and recent food webs point to deep principles underpinning the structure of ecological relationships, as shown by researchers from the Santa Fe Institute, Microsoft Research Cambridge and elsewhere. Analyses of Chengjiang and Burgess Shale food-web data suggest that most, but not all, aspects of the trophic structure of modern ecosystems were in place over a half-billion years ago. It was an Anomalocaris-eat-trilobite world, filled with species like nothing on today’s Earth. But the ecology of Cambrian communities was remarkably modern, say researchers behind the first study to reconstruct detailed food webs for ancient ecosystems. Their paper suggests that networks of feeding relationships among marine species that lived hundreds of millions of years ago are remarkably similar to those of today.

Bison Can Thrive Again, Study Says:

Bison can repopulate large areas from Alaska to Mexico over the next 100 years provided a series of conservation and restoration measures are taken, according to continental assessment of this iconic species by the Wildlife Conservation Society and other groups.

Birds Can Detect Predators Using Smell:

Many animal species detect and avoid predators by smell, but this ability has largely been ignored in the study of birds, since it was traditionally thought that they did not make use of this sense. However, it has now been discovered that birds are not only capable of discerning their enemies through chemical signals, but that they also alter their behaviour depending on the perceived level of risk of predation.

Help For Insomnia Patients? Different Processes Govern Sight, Light Detection:

A Johns Hopkins University biologist, in research with implications for people suffering from seasonal affective disorder and insomnia, has determined that the eye uses light to reset the biological clock through a mechanism separate from the ability to see.

When Did Dinosaurs Go Extinct? Cretaceous-Tertiary Boundary Dating Refined:

Scientists at the University of California, Berkeley, and the Berkeley Geochronology Center have pinpointed the date of the dinosaurs’ extinction more precisely than ever thanks to refinements to a common technique for dating rocks and fossils.

Tropical Reforestation Aided By Bats:

German scientists are engaging bats to kick-start natural reforestation in the tropics by installing artificial bat roosts in deforested areas. This novel method for tropical restoration is presented in a new study published online in the science journal Conservation Biology this week. Detlev Kelm from the Leibniz Institute for Zoo and Wildlife Research in Berlin (IZW) and Kerstin Wiesner and Otto von Helversen from the University of Erlangen-Nuremberg report that the deployment of artificial bat roosts significantly increases seed dispersal of a wide range of tropical forest plants into their surroundings, providing a simple and cheap method to speed up natural forest regeneration.

Why We Sleep: The Temporal Organization of Recovery:

“If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made,” Allan Rechtschaffen said. Studies of sleep and sleep deprivation suggest that the functions of sleep include recovery at the cellular, network, and endocrine system levels, energy conservation and ecological adaptations, and a role in learning and synaptic plasticity.

One Rhodopsin per Photoreceptor: Iro-C Genes Break the Rule:

A long-standing general principle in vision research holds that single photoreceptors always contain a single type of rhodopsin, although occasional examples of co-expressed rhodopsins, as the authors have now demonstrated for Drosophila, have cropped up in both vertebrates and invertebrates.

Compilation and Network Analyses of Cambrian Food Webs:

Food webs, which depict the networks of feeding interactions among co-occurring species, display many regularities in their structure. For example, the distributions of links to prey and links from predators, the percentages of omnivores and herbivores, and the mean trophic level of species change systematically with the number of taxa and feeding links in a web. Such “scale-dependent” regularities are formalized by network models based on a few simple link distribution rules that successfully predict the network structure of complex food webs from a variety of habitats. To explore how long such regularities may have persisted, we compiled and analyzed detailed food-web data for two ancient fossil assemblages from the early Paleozoic, when rapid diversification of multicellular species, body plans, and trophic roles occurred. Our analyses show that for most aspects of network structure, the Early Cambrian Chengjiang Shale and Middle Cambrian Burgess Shale food webs are very similar to modern webs. This suggests that there are strong and enduring constraints on the organization of feeding interactions in ecosystems. However, a few differences, particularly in the Chengjiang Shale web, suggest that some aspects of network structure were still in flux during early phases of de novo ecosystem construction.

Better Reporting, Better Research: Guidelines and Guidance in PLoS Medicine:

PLoS Medicine aims to publish important studies from all medical disciplines that provide a substantial advance either in clinical practice, public heath policy, or basic pathophysiology. Though this is a lofty aim it is possible to see the journal’s role as primarily a passive one; presubmission inquiries and research articles arrive unsolicited, by which time evaluation by editors and reviewers for rigor, originality, and importance can do little to improve deficiencies in study methodology (largely a fait accompli by that point). However, we would argue that medical journals such as PLoS Medicine should seek to go beyond merely reflecting current trends in medical practice and research, by actively working to establish and promote standards that aim to improve the quality of research that is done.

Standardising Outcomes in Paediatric Clinical Trials:

In a new systematic review published in this issue of PLoS Medicine, Ian Sinha and colleagues examined studies that involved the selection of outcomes for use in paediatric clinical trials [2]. As they say in their report, the choice of outcome is important because choosing inappropriate outcomes may lead to “wasted resources or misleading information which either overestimates, underestimates or completely misses the potential benefits of an intervention.”

Early Human Populations Evolved Separately For 100,000 Years:

A team of Genographic researchers and their collaborators have published the most extensive survey to date of African mitochondrial DNA (mtDNA). Over 600 complete mtDNA genomes from indigenous populations across the continent were analyzed by the scientists, led by Doron Behar, Genographic Associate Researcher, based at Rambam Medical Center, Haifa, and Saharon Rosset of IBM T.J. Watson Research Center, NY and Tel Aviv University. Analyses of the extensive data presented in this study provide surprising insights into the early demographic history of human populations before they moved out of Africa, illustrating that these early human populations were small and isolated from each other for many tens of thousands of years.

Insects Use Plants Like A Telephone:

Dutch ecologist Roxina Soler and her colleagues have discovered that subterranean and aboveground herbivorous insects can communicate with each other by using plants as telephones. Subterranean insects issue chemical warning signals via the leaves of the plant. This way, aboveground insects are alerted that the plant is already ‘occupied’.

Rare Musk Ox May Be Threatened By Climate Change:

The Wildlife Conservation Society (WCS) recently launched a four-year study to determine if climate change is affecting populations of a quintessential Arctic denizen: the rare musk ox. Along with collaborators from the National Park Service, U. S. Geological Survey, and Alaska Fish and Game, Wildlife Conservation Society researchers have already equipped six musk ox with GPS collars to better understand how climate change may affect these relics of the Pleistocene.

Biodiversity Is Crucial To Ecosystem Productivity:

In the first experiment involving a natural environment, scientists at Brown University have shown that richer plant diversity significantly enhances an ecosystem’s productivity. The finding underscores the benefits of biodiversity, such as capturing carbon dioxide, a main contributor to global warming.

Dinosaurs Probably Lacked Tissue To Generate Heat:

A team of researchers at New York Medical College has discovered why birds, unlike mammals, lack a tissue that is specialized to generate heat. A new paper contains the surprising implication that the same lack of heat-generating tissue may have contributed to the extinction of dinosaurs.

Lizard Hunting Styles Impact Ability To Walk, Run:

The technique lizards use to grab their grub influences how they move, according to researchers at Ohio University. A research team led by doctoral student Eric McElroy tracked 18 different species of lizards as they walked or ran in order to understand how their foraging styles impact their biomechanics.

Arctic Marine Mammals On Thin Ice:

The loss of sea ice due to climate change could spell disaster for polar bears and other Arctic marine mammals. Sea ice is the common habitat feature uniting these unique and diverse Arctic inhabitants. Sea ice serves as a platform for resting and reproduction, influences the distribution of food sources, and provides a refuge from predators. The loss of sea ice poses a particularly severe threat to Arctic species, such as the hooded seal, whose natural history is closely tied to, and depends on, sea ice.

Nurture Over Nature: Certain Genes Are Turned On Or Off By Geography And Lifestyle, Study Suggests:

Score one for the nurture side of the nature vs. nurture debate, as North Carolina State University geneticists have shown that environmental factors such as lifestyle and geography play a large role in whether certain genes are turned on or off. By studying gene expression of white blood cells in 46 Moroccan Amazighs, or Berbers – including desert nomads, mountain agrarians and coastal urban dwellers – the NC State researchers and collaborators in Morocco and the United States showed that up to one-third of genes are differentially expressed due to where and how the Moroccan Amazighs live.

Human Brain Appears ‘Hard-wired’ For Hierarchy:

Human imaging studies have for the first time identified brain circuitry associated with social status, according to researchers at the National Institute of Mental Health (NIMH) of the National Institutes of Health. They found that different brain areas are activated when a person moves up or down in a pecking order — or simply views perceived social superiors or inferiors. Circuitry activated by important events responded to a potential change in hierarchical status as much as it did to winning money.

Infant Carrying Ruled Out As Reason Why Early Humans Walked Upright, According To New Research:

Scientists investigating the reasons why early humans — the so-called hominins — began walking upright say it’s unlikely that the need to carry children was a factor, as has previously been suggested.

Shell-breaking Crabs Lived 20 Million Years Earlier Than Thought:

While waiting for colleagues at a small natural history museum in the state of Chiapas, Mexico last year, Cornell paleontologist Greg Dietl chanced upon a discovery that has helped rewrite the evolutionary history of crabs and the shelled mollusks upon which they preyed.

Reputation And Money: New Insights Into How The Brain Processes Social, Economic Reward:

Researchers have mapped the brain regions that process social standing and money rewards, yielding new insights that they said will aid understanding of the basis of social behaviors.

On The High Horse: Why Dominant Individuals Climb The Proverbial Ladder:

Psychological findings imply that a person’s level of dominance could be measured based on their biases favoring vertical representations of power, as is the case in a hierarchy. In an attempt to grasp complex concepts, humans have tried to represent abstractions like power and dominance through visually-stimulated metaphors such as pyramids and steeples. And dominance especially has been measured socially, linguistically and artistically on a vertical dimension, as with upper and lower class divisions in hierarchical structures.

What’s Not To Like? Why Fondness Makes Us Poor Judges, But Dislike Is Spot-on:

How good are we at guessing other people’s likes and dislikes? Ever bring a favorite dish to a potluck — only to watch it go uneaten? Or receive an unwelcome shock when a cherished product is discontinued for lack of sales? People have the tendency to assume the whole world likes what we like, reveals new research from the June 2008 issue of the Journal of Consumer Research. However, we don’t generalize the same way when it comes to things we hate.

Coke Or Pepsi? Being Distracted Can Make You More Susceptible To Ads:

A can of Coke next to the word “awesome”; a can of Pepsi next to a picture of a happy couple. Seem too basic to be effective advertising? Prior research has shown that reported attitudes towards brands are not affected by such simple juxtapositions. However, a new paper in the June 2008 issue of the Journal of Consumer Research examines our implicit opinions — and finds that we may actually be more susceptible than we think.

Molecular Analysis Confirms Tyrannosaurus Rex’s Evolutionary Link To Birds:

Putting more meat on the theory that dinosaurs’ closest living relatives are modern-day birds, molecular analysis of a shred of 68-million-year-old Tyrannosaurus rex protein — along with that of 21 modern species — confirms that dinosaurs share common ancestry with chickens, ostriches, and to a lesser extent, alligators.

There are 41 new articles published this week in PLoS ONE. A always, make comments and ratings while browsing and reading the articles. Here are just a few picks – titles I found interesting – but you should go and check all the others as well:
Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest:

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans.

Interactive ‘Video Doctor’ Counseling Reduces Drug and Sexual Risk Behaviors among HIV-Positive Patients in Diverse Outpatient Settings:

Reducing substance use and unprotected sex by HIV-positive persons improves individual health status while decreasing the risk of HIV transmission. Despite recommendations that health care providers screen and counsel their HIV-positive patients for ongoing behavioral risks, it is unknown how to best provide “prevention with positives” in clinical settings. Positive Choice, an interactive, patient-tailored computer program, was developed in the United States to improve clinic-based assessment and counseling for risky behaviors. We conducted a parallel groups randomized controlled trial (December 2003-September 2006) at 5 San Francisco area outpatient HIV clinics. Eligible patients (HIV-positive English-speaking adults) completed an in-depth computerized risk assessment. Participants reporting substance use or sexual risks (n = 476) were randomized in stratified blocks. The intervention group received tailored risk-reduction counseling from a “Video Doctor” via laptop computer and a printed Educational Worksheet; providers received a Cueing Sheet on reported risks. Compared with control, fewer intervention participants reported continuing illicit drug use (RR 0.81, 95% CI: 0.689, 0.957, p = 0.014 at 3 months; and RR 0.65, 95% CI: 0.540, 0.785, p<0.001 at 6 months) and unprotected sex (RR 0.88, 95% CI: 0.773, 0.993, p = 0.039 at 3 months; and RR 0.80, 95% CI: 0.686, 0.941, p = 0.007 at 6 months). Intervention participants reported fewer mean days of ongoing illicit drug use (-4.0 days vs. -1.3 days, p = 0.346, at 3 months; and -4.7 days vs. -0.7 days, p = 0.130, at 6 months) than did controls, and had fewer casual sex partners at (−2.3 vs. −1.4, p = 0.461, at 3 months; and −2.7 vs. −0.6, p = 0.042, at 6 months). The Positive Choice intervention achieved significant cessation of illicit drug use and unprotected sex at the group-level, and modest individual-level reductions in days of ongoing drug use and number of casual sex partners compared with the control group. Positive Choice, including Video Doctor counseling, is an efficacious and appropriate adjunct to risk-reduction efforts in outpatient settings, and holds promise as a public health HIV intervention.

Marine Incursion: The Freshwater Herring of Lake Tanganyika Are the Product of a Marine Invasion into West Africa:

The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika’s biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25-50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa’s Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics.

Truncated Power Laws Reveal a Link between Low-Level Behavioral Processes and Grouping Patterns in a Colonial Bird:

Departures from power law group size frequency distributions have been proposed as a useful tool to link individual behavior with population patterns and dynamics, although examples are scarce for wild animal populations. We studied a population of Lesser kestrels (Falco naumanni) breeding in groups (colonies) from one to ca. 40 breeding pairs in 10,000 km2 in NE Spain. A 3.5 fold steady population increase occurred during the eight-year study period, accompanied by a geographical expansion from an initial subpopulation which in turn remained stable in numbers. This population instability was mainly driven by first-breeders, which are less competitive at breeding sites, being relegated to breed solitarily or in small colony sizes, and disperse farther than adults. Colony size frequency distributions shifted from an initial power law to a truncated power law mirroring population increase. Thus, we hypothesized that population instability was behind the truncation of the power law. Accordingly, we found a power law distribution through years in the initial subpopulation, and a match between the power law breakpoint (at ca. ten pairs) and those colony sizes from which the despotic behavior of colony owners started to impair the settlement of newcomers. Moreover, the instability hypothesis was further supported by snapshot data from another population of Lesser kestrels in SW Spain suffering a population decline. Appropriate analysis of the scaling properties of grouping patterns has unraveled the link between local agonistic processes and large-scale (population) grouping patterns in a wild bird population.

Floral Temperature and Optimal Foraging: Is Heat a Feasible Floral Reward for Pollinators?:

As well as nutritional rewards, some plants also reward ectothermic pollinators with warmth. Bumble bees have some control over their temperature, but have been shown to forage at warmer flowers when given a choice, suggesting that there is some advantage to them of foraging at warm flowers (such as reducing the energy required to raise their body to flight temperature before leaving the flower). We describe a model that considers how a heat reward affects the foraging behaviour in a thermogenic central-place forager (such as a bumble bee). We show that although the pollinator should spend a longer time on individual flowers if they are warm, the increase in total visit time is likely to be small. The pollinator’s net rate of energy gain will be increased by landing on warmer flowers. Therefore, if a plant provides a heat reward, it could reduce the amount of nectar it produces, whilst still providing its pollinator with the same net rate of gain. We suggest how heat rewards may link with plant life history strategies.

Cooperation and Deception Recruit Different Subsets of the Theory-of-Mind Network:

The term “theory of mind” (ToM) describes an evolved psychological mechanism that is necessary to represent intentions and expectations in social interaction. It is thus involved in determining the proclivity of others to cooperate or defect. While in cooperative settings between two parties the intentions and expectations of the protagonists match, they diverge in deceptive scenarios, in which one protagonist is intentionally manipulated to hold a false belief about the intention of the other. In a functional magnetic resonance imaging paradigm using cartoons showing social interactions (including the outcome of the interaction) between two or three story characters, respectively, we sought to determine those brain areas of the ToM network involved in reasoning about cooperative versus deceptive interactions. Healthy volunteers were asked to reflect upon the protagonists’ intentions and expectations in cartoons depicting cooperation, deception or a combination of both, where two characters cooperated to deceive a third. Reasoning about the mental states of the story characters yielded substantial differences in activation patterns: both deception and cooperation activated bilateral temporoparietal junction, parietal and cingulate regions, while deception alone additionally recruited orbitofrontal and medial prefrontal regions. These results indicate an important role for prefrontal cortex in processing a mismatch between a character’s intention and another’s expectations as required in complex social interactions.

Orexigenic Hormone Ghrelin Attenuates Local and Remote Organ Injury after Intestinal Ischemia-Reperfusion:

Gut ischemia/reperfusion (I/R) injury is a serious condition in intensive care patients. Activation of immune cells adjacent to the huge endothelial cell surface area of the intestinal microvasculature produces initially local and then systemic inflammatory responses. Stimulation of the vagus nerve can rapidly attenuate systemic inflammatory responses through inhibiting the activation of macrophages and endothelial cells. Ghrelin, a novel orexigenic hormone, is produced predominately in the gastrointestinal system. Ghrelin receptors are expressed at a high density in the dorsal vagal complex of the brain stem. In this study, we investigated the regulation of the cholinergic anti-inflammatory pathway by the novel gastrointestinal hormone, ghrelin, after gut I/R. Gut ischemia was induced by placing a microvascular clip across the superior mesenteric artery for 90 min in male adult rats. Our results showed that ghrelin levels were significantly reduced after gut I/R and that ghrelin administration inhibited pro-inflammatory cytokine release, reduced neutrophil infiltration, ameliorated intestinal barrier dysfunction, attenuated organ injury, and improved survival after gut I/R. Administration of a specific ghrelin receptor antagonist worsened gut I/R-induced organ injury and mortality. To determine whether ghrelin’s beneficial effects after gut I/R require the intact vagus nerve, vagotomy was performed in sham and gut I/R animals immediately prior to the induction of gut ischemia. Our result showed that vagotomy completely eliminated ghrelin’s beneficial effect after gut I/R. To further confirm that ghrelin’s beneficial effects after gut I/R are mediated through the central nervous system, intracerebroventricular administration of ghrelin was performed at the beginning of reperfusion after 90-min gut ischemia. Our result showed that intracerebroventricular injection of ghrelin also protected the rats from gut I/R injury. These findings suggest that ghrelin attenuates excessive inflammation and reduces organ injury after gut I/R through activation of the cholinergic anti-inflammatory pathway.

Life Expectancy Worsening Or Stagnating For Large Segment Of U.S. Population:

One of the major aims of the U.S. health system is improving the health of all people, particularly those segments of the population at greater risk of health disparities. In fact, overall life expectancy in the U.S. increased more than seven years for men and more than six years for women between 1960 and 2000. Now, a new, long-term study of mortality trends in U.S. counties over the same four decades reports a troubling finding: These gains are not reaching many parts of the country; rather, the life expectancy of a significant segment of the population is declining or at best stagnating.

Shell-breaking Crabs Lived 20 Million Years Earlier Than Thought:

While waiting for colleagues at a small natural history museum in the state of Chiapas, Mexico last year, Cornell paleontologist Greg Dietl chanced upon a discovery that has helped rewrite the evolutionary history of crabs and the shelled mollusks upon which they preyed.

Birds Announce Their Sentry Duty To Help Comrades Get A Good Meal:

Soldiers on sentry duty in hostile territory keep in regular radio contact with their colleagues to assure them that all is well and that they are safe to carry on their manoeuvres. New research reveals that this is also a feature of the bird world and is very likely to be a rare example of truly cooperative behaviour.

Variety Is The Spice Of Life: Too Many Males, Too Little Time…:

Female Australian painted dragon lizards are polyandrous, that is, they mate with as many males as they can safely get access to. This promiscuous behaviour is often found in species where male quality is dubious and there are high levels of infertility in the male population.

Building A Global Reference Library Of DNA Barcodes Of Marine Life:

Most of us are familiar with bar codes, those small black stripes with numbers below, known as the Universal Product Code or UPC label, that appear on commercial products. We scan them at the grocery store or to check a price, or have to cut them out and send them in for a rebate.

Mutations in a Novel, Cryptic Exon of the Luteinizing Hormone/Chorionic Gonadotropin Receptor Gene Cause Male Pseudohermaphroditism:

A person’s sex is determined by their complement of X and Y (sex) chromosomes. Someone who has two X chromosomes is genetically female and usually has ovaries and female external sex organs. Someone who has an X and a Y chromosome is genetically male and has testes and male external sex organs. Sometimes, though, the development of the reproductive organs proceeds abnormally, resulting in a person with an “intersex” condition whose chromosomes, gonads (ovaries or testes), and external sex organs do not correspond. Leydig cell hypoplasia (LCH; also called male pseudohermaphroditism or a disorder of sex development) is an XY female intersex condition. People with this inherited condition develop testes but also have a vagina (which is not connected to a womb), and they do not develop breasts or have periods. This mixture of sexual characteristics arises because the Leydig cells in the testes are underdeveloped. Leydig cells normally secrete testosterone, the hormone that promotes the development and maintenance of male sex characteristics. Before birth, chorionic gonadotropin (CG; a hormone made by the placenta) stimulates Leydig cell development and testosterone production; after birth, luteinizing hormone (LH), which is made by the pituitary gland, stimulates testosterone production. Both hormones bind to the LH/CG receptor, a protein on the surface of Leydig cells. In LCH, this receptor either does not bind CG and LH or fails to tell the Leydig cells to make testosterone.
—————-
These findings identify a new, functional exon in the LHCGR gene and show that mutations in this exon cause some cases of LCH. This is the first time that a human disease has been associated with mutations in an exon that is a target for NMD. In addition, these findings provide important insights into how the LHCGR is regulated. The researchers speculate that a complex network that involves the exon 6A-containing transcripts and NMD normally tightly regulates the production of functional LHCGR already at the transcriptional level. When mutations are present in exon 6A, they suggest, NMD is the predominant pathway for all the exon 6A-containing transcripts, thereby drastically decreasing the amount of functional LHCGR.

Iroquois Complex Genes Induce Co-Expression of rhodopsins in Drosophila:

Most sensory systems follow the rule “one receptor molecule per receptor cell.” For example, photoreceptors in the fly eye and cones in the human eye each express only one light-sensitive rhodopsin. Rhodopsins are G-coupled protein receptors, a class of ancient signaling molecules that mediate not just vision but also the sense of smell, the inflammatory response, and other physiological processes. However, the mechanisms that regulate mutual exclusion of receptor genes in the visual and olfactory systems are poorly understood. Each ommatidium in the fly eye consists of eight photoreceptors (R1-R8); six of which mediate broad-spectrum motion vision (R1-R6) and two that mediate color vision (R7 and R8). We identified a new class of photoreceptors in the fly retina that violates the one rhodopsin-one receptor rule. This subset of ommatidia, located in the dorsal third of the eye, co-expresses two ultraviolet-sensitive rhodospins (rh3 and rh4) in R7, while maintaining discrimination between green and blue opsins in R8. We took advantage of the genetic tools offered by the fruit fly to show that this co-expression depends on the Iroquois Complex (Iro-C) genes that are both necessary and sufficient to allow the two ultraviolet-sensitive rhosopsins to be expressed in the same R7 cell. These results shed new light on the mechanisms regulating co-expression of rhodopsins in the eye, and may well have implications for regulating co-expression in olfactory receptors and other G-protein coupled systems.

Neanderthals Speak Again After 30,000 Years:

Dr. Robert McCarthy, an assistant professor of anthropology in the Dorothy F. Schmidt College of Arts and Letters at Florida Atlantic University, has reconstructed vocal tracts that simulate the sound of the Neanderthal voice.

Slowly-developing Primates Definitely Not Dim-witted:

Some primates have evolved big brains because their extra brainpower helps them live and reproduce longer, an advantage that outweighs the demands of extra years of growth and development they spend reaching adulthood, anthropologists from Duke University and the University of Zurich have concluded in a new study.

Researchers Identify New Class Of Photoreceptors, Pointing To New Ways Sights And Smells Are Regulated:

The identification of a new class of photoreceptors in the retina of fruit flies sheds light on the regulation of the pigments of the eye that confer color vision, researchers at New York University’s Center for Developmental Genetics report in a new study appearing in the Public Library of Science’s journal, PloS Biology. The findings, they write, may also have implications for the regulating of olfactory receptors, which are responsible for the detection of smells, because both types of receptors belong to the same protein family.

Low Grades, Bad Behavior? Siblings May Be To Blame, Study Say:

We all know the story of a man named Brady and the group that somehow formed a family. But if the iconic ’70s sitcom about a “blended” family reflected reality, the Brady Bunch likely would have been dealing with much more than silly sibling squabbles. Here’s the real story: On average, adolescents living with half- or stepsiblings have lower grades and more school-related behavior problems, and these problems may not improve over time, according to Florida State University Assistant Professor of Sociology Kathryn Harker Tillman.

Many Captive Tigers Are Of Purebred Ancestry; Finding Raises Their Conservation Value:

Tigers held in captivity around the world–including those in zoos, circuses, and private homes–may hold considerable conservation value for the rapidly dwindling wild populations around the world, according to a new report published online on April 17th in Current Biology. Using a new method for assessing the genetic ancestry of tigers, researchers discovered that many apparently “generic” tigers actually represent purebred subspecies and harbor genomic diversity no longer found in nature.

Mice Can Sense Oxygen Through Their Skin:

Biologists at the University of California, San Diego have discovered that the skin of mice can sense low levels of oxygen and regulate the production of erythropoietin, or EPO, the hormone that stimulates our bodies to produce red blood cells and allows us to adapt to high-altitude, low-oxygen environments.

Mighty Microbes: Bacteria Filaments Can Bundle Together And Move Objects 100,000 Times Bacterium’s Body Weight:

Researchers from The University of Arizona and Columbia University have discovered that tiny filaments on bacteria can bundle together and pull with forces far stronger than experts had previously thought possible.

Work Hassles Hamper Sleep, Study Shows:

Common hassles at work are more likely than long hours, night shifts or job insecurity to follow workers home and interfere with their sleep. That’s the conclusion of a University of Michigan study presented April 17 at the annual meeting of the Population Association of America.

Are Humans Hardwired For Fairness?:

Is fairness simply a ruse, something we adopt only when we secretly see an advantage in it for ourselves? Many psychologists have in recent years moved away from this purely utilitarian view, dismissing it as too simplistic. Recent advances in both cognitive science and neuroscience now allow psychologists to approach this question in some different ways, and they are getting some intriguing results.

Older People Are Nation’s Happiest: Baby Boomers Less Happy Than Other Generational Groups:

Americans grow happier as they grow older, according to a University of Chicago study that is one of the most thorough examinations of happiness ever done in America.

Early Elephant ‘Was Amphibious’:

The scientists were investigating the lifestyle of two early elephants (proboscideans) Moeritherium and Barytherium that lived in the Eocene period, over 37 million years ago. By analysing isotopes in tooth enamel from Moeritherium they were able to deduce that it was very likely a semi-aquatic mammal, spending its days in water eating freshwater plants.’

Clues To Ancestral Origin Of Placenta Emerge In Genetics Study:

Researchers at the Stanford University School of Medicine have uncovered the first clues about the ancient origins of a mother’s intricate lifeline to her unborn baby, the placenta, which delivers oxygen and nutrients critical to the baby’s health.

Lizards Undergo Rapid Evolution After Introduction To A New Home:

In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. Now, an international team of researchers has shown that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo rapid and large-scale evolutionary changes.

Presumed Extinct Javan Elephants May Have Been Found Again – In Borneo:

The Borneo pygmy elephant may not be native to Borneo after all. Instead, the population could be the last survivors of the Javan elephant race – accidentally saved from extinction by the Sultan of Sulu centuries ago, a new publication suggests.

We were too busy to notice, but apparently, PLoS ONE reached a new milestone this week – the 2000th article! Wow! That’s a lot!
This week we have a new Journal Club, already getting lively so you should all picth in and add your comments to the discussion. It is on the article on human evolution: Identifying Selected Regions from Heterozygosity and Divergence Using a Light-Coverage Genomic Dataset from Two Human Populations and the commentary can be found here.
And here are some titles from this week’s crop that got my attention – the first one listed being the first Taxonomy article ever published in PLoS:
A Supplementary Description of Cypridina mariae and Rediagnosis of the Genus Cylindroleberis (Ostracoda: Myodocopa: Cylindroleberididae):

The ostracod family Cylindroleberididae is based on the genus Cylindroleberis Brady, 1868, and has a complicated nomenclatural history. The type species of Cylindroleberis is Cypridina mariae Baird, 1850. Baird described only the carapace, which had been considered lost. Thus, there was no reference point for the concept C. mariae or the genus Cylindroleberis. Baird’s material has now been found in the Natural History Museum, London, U.K., and is illustrated here. To clarify the taxonomic status of C. mariae and Cylindroleberis, specimens were obtained from near the type locality, and a supplementary description is presented. This includes description of appendages, particularly the first antenna and mandible, which contain important diagnostic characters. This supplementary description provides important information about C. mariae, allowing a revision of the genus Cylindroleberis, and establishing a framework for future biological research on this ostracod group.

Does Sex Trade with Violence among Genotypes in Drosophila melanogaster?:

The evolutionary forces shaping the ability to win competitive interactions, such as aggressive encounters, are still poorly understood. Given a fitness advantage for competitive success, variance in aggressive and sexual display traits should be depleted, but a great deal of variation in these traits is consistently found. While life history tradeoffs have been commonly cited as a mechanism for the maintenance of variation, the variability of competing strategies of conspecifics may mean there is no single optimum strategy. We measured the genetically determined outcomes of aggressive interactions, and the resulting effects on mating success, in a panel of diverse inbred lines representing both natural variation and artificially selected genotypes. Males of one genotype which consistently lost territorial encounters with other genotypes were nonetheless successful against males that were artificially selected for supernormal aggression and dominated all other lines. Intransitive patterns of territorial success could maintain variation in aggressive strategies if there is a preference for territorial males. Territorial success was not always associated with male mating success however and females preferred ‘winners’ among some male genotypes, and ‘losers’ among other male genotypes. This suggests that studying behaviour from the perspective of population means may provide limited evolutionary and genetic insight. Overall patterns of competitive success among males and mating transactions between the sexes are consistent with mechanisms proposed for the maintenance of genetic variation due to nonlinear outcomes of competitive interactions.

Seasonal Activity Budget of Adult Baltic Ringed Seals:

Although ringed seals are important components in oceanic and fresh water ecosystems at high latitudes, little is known about how they exploit these harsh environments. Seasonal activity and diving behaviour of 19 adult Baltic ringed seals were studied by satellite telemetry. We elaborated an activity budget for ten months of the year, extending over the period from moult to the breeding season. Seals from three main regions showed explicit site fidelity and the distributions of animals tagged from different areas did not overlap, suggesting separate stocks. Both the mean duration and the mean depth of dives peaked in June and July. Seals spent 70% (females) to 85% (males) of their time diving in June and July which decreased to 50% in late autumn. Less than one percent of dives exceeded 10 min in females, while 10% of male dives lasted longer than 10 min in June to September. Less than one percent of dives lasted for more than 25 min. Both females and males were most active during day time and hauled out predominantly during the night. Activity patterns during the summer are suggested to be correlated to energy accumulation and prey availability. The information on seasonal activity budget is crucial for developing population energetic models where interactions between ringed seals and other trophic levels can be evaluated.

Optimal Foraging Predicts the Ecology but Not the Evolution of Host Specialization in Bacteriophages:

We explore the ability of optimal foraging theory to explain the observation among marine bacteriophages that host range appears to be negatively correlated with host abundance in the local marine environment. We modified Charnov’s classic diet composition model to describe the ecological dynamics of the related generalist and specialist bacteriophages φX174 and G4, and confirmed that specialist phages are ecologically favored only at high host densities. Our modified model accurately predicted the ecological dynamics of phage populations in laboratory microcosms, but had only limited success predicting evolutionary dynamics. We monitored evolution of attachment rate, the phenotype that governs diet breadth, in phage populations adapting to both low and high host density microcosms. Although generalist φX174 populations evolved even broader diets at low host density, they did not show a tendency to evolve the predicted specialist foraging strategy at high host density. Similarly, specialist G4 populations were unable to evolve the predicted generalist foraging strategy at low host density. These results demonstrate that optimal foraging models developed to explain the behaviorally determined diets of predators may have only limited success predicting the genetically determined diets of bacteriophage, and that optimal foraging probably plays a smaller role than genetic constraints in the evolution of host specialization in bacteriophages.

Seasonal Migration Determined by a Trade-Off between Predator Avoidance and Growth:

Migration is a common phenomenon in many organisms, terrestrial as well as aquatic, and considerable effort has been spent to understand the evolution of migratory behaviour and its consequences for population and community dynamics. In aquatic systems, studies on migration have mainly been focused on commercially important fish species, such as salmon and trout. However, seasonal mass-migrations may occur also among other freshwater fish, e.g. in cyprinids that leave lakes and migrate into streams and wetlands in the fall and return back to the lake in spring. In a conceptual model, we hypothesized that this is an adaptive behaviour in response to seasonal changes in predation (P) and growth (G) and that migrating fish change habitat so as to minimise the ratio between predation mortality and growth rate (P/G). Estimates from bioenergetic modelling showed that seasonal changes in the ratio between predator consumption rate and prey growth rate followed the predictions from the conceptual model and also gave more precise predictions for the timing of the habitat change. By quantifying the migration of more than 1800 individually marked fish, we showed that actual migration patterns followed predictions with a remarkable accuracy, suggesting that migration patterns have evolved in response to seasonally fluctuating trade-offs between predator avoidance and foraging gains. Thus, the conceptual model provides a mechanistic understanding to mass-migration in prey fish. Further, we also show that the dominant prey fish is actually absent from the lake during a major part of the year, which should have strong implications for the dynamics of the lake ecosystem through direct and indirect food-web interactions.

Cyclic and Sleep-Like Spontaneous Alternations of Brain State Under Urethane Anaesthesia:

Although the induction of behavioural unconsciousness during sleep and general anaesthesia has been shown to involve overlapping brain mechanisms, sleep involves cyclic fluctuations between different brain states known as active (paradoxical or rapid eye movement: REM) and quiet (slow-wave or non-REM: nREM) stages whereas commonly used general anaesthetics induce a unitary slow-wave brain state. Long-duration, multi-site forebrain field recordings were performed in urethane-anaesthetized rats. A spontaneous and rhythmic alternation of brain state between activated and deactivated electroencephalographic (EEG) patterns was observed. Individual states and their transitions resembled the REM/nREM cycle of natural sleep in their EEG components, evolution, and time frame (~11 minute period). Other physiological variables such as muscular tone, respiration rate, and cardiac frequency also covaried with forebrain state in a manner identical to sleep. The brain mechanisms of state alternations under urethane also closely overlapped those of natural sleep in their sensitivity to cholinergic pharmacological agents and dependence upon activity in the basal forebrain nuclei that are the major source of forebrain acetylcholine. Lastly, stimulation of brainstem regions thought to pace state alternations in sleep transiently disrupted state alternations under urethane. Our results suggest that urethane promotes a condition of behavioural unconsciousness that closely mimics the full spectrum of natural sleep. The use of urethane anaesthesia as a model system will facilitate mechanistic studies into sleep-like brain states and their alternations. In addition, it could also be exploited as a tool for the discovery of new molecular targets that are designed to promote sleep without compromising state alternations.

Unique Environmental Effects on Physical Activity Participation: A Twin Study:

The health benefits of regular physical activity are well established. However, the relative contribution of heritable and environmental factors to physical activity participation remains controversial. Using a cut-point of 60 minutes of total activity per week, data from the GenomEUtwin project revealed consistent genetic influence on physical activity participation in 37,051 twin pairs from seven countries. We hypothesized that the heritability of physical activity participation would be attenuated using the CDC/ACSM recommended minimum threshold of 150 minutes of moderate intensity activity per week. Data were obtained from 1,389 twin pairs from the community-based University of Washington Twin Registry. Twin similarity in physical activity participation using both cut-points was analyzed using tetrachoric correlations and structural equation modeling in all same-sex pairs. Correlations were higher in monozygotic (rMZ = 0.43, 95% CI = 0.33-0.54) than dizygotic pairs (rDZ = 0.30, 95% CI = 0.12-0.47) using the 60 minute cut-point. However, differences were attenuated using the 150 minute standard (rMZ = 0.30, 95% CI = 0.20-0.40; rDZ = 0.25, 95% CI = 0.07-0.42). Using the lower cut-point, the best fitting model of twin resemblance only included additive genetics and unique environment, with a heritability of 45%. In contrast, using the higher threshold, the best fitting model included the common and unique environment, with the unique environment contributing 72% of the variance. Unique environment factors provide the strongest influence on physical activity participation at levels recommended for health benefits.

Antioxidant Users Don’t Live Longer, Analysis Of Studies Concludes:

The vitamin industry has long touted antioxidants as a way to improve health by filling in gaps in diet, but a new review of studies found no evidence that the nutrition supplements extend life. Worse, the review authors said that some antioxidants could increase risk for death.

Researchers Mimic Bacteria To Produce Magnetic Nanoparticles:

When it comes to designing something, it’s hard to find a better source of inspiration than Mother Nature. Using that principle, a diverse, interdisciplinary group of researchers at the U.S. Department of Energy’s Ames Laboratory is mimicking bacteria to synthesize magnetic nanoparticles that could be used for drug targeting and delivery, in magnetic inks and high-density memory devices, or as magnetic seals in motors. Commercial room-temperature synthesis of ferromagnetic nanoparticles is difficult because the particles form rapidly, resulting in agglomerated clusters of particles with less than ideal crystalline and magnetic properties. Size also matters. As particles get smaller, their magnetic properties, particularly with regard to temperature, also diminish. However, several strains of bacteria produce magnetite (Fe3O4) – fine, uniform nanoparticles that have desirable magnetic properties. These magnetotactic bacteria use a protein to form crystalline particles about 50 nanometers in size. These crystals are bound by membranes to form chains of particles which the bacteria use like a compass needle to orient themselves with the Earth’s magnetic field.

Decision-making May Be Surprisingly Unconscious Activity:

Contrary to what most of us would like to believe, decision-making may be a process handled to a large extent by unconscious mental activity. A team of scientists has unraveled how the brain actually unconsciously prepares our decisions. Even several seconds before we consciously make a decision its outcome can be predicted from unconscious activity in the brain.

Community-based Approach Best Bet To Control Free-roaming Cats, Survey Suggests:

A survey gauging Ohioans’ attitudes about free-roaming cats suggests that no single statewide measure would be sufficient in managing cat overpopulation because public opinion about outdoor cats varies widely across the state.

Bikini Corals Recover From Atomic Blast, Although Some Species Missing:

Half a century after the last earth-shattering atomic blast shook the Pacific atoll of Bikini, the corals are flourishing again. Some coral species, however, appear to be locally extinct.

Fittest Males Don’t Always Get The Girl:

The fittest males don’t always get the girl, USC biologists report. Study tackles a paradox in species from fruit flies to humans: If warriors win the spoils, why don’t males evolve towards super-aggressiveness?

Deep-sea Sharks Wired For Sound:

Deep-sea sharks have been tagged and tracked and their habitats precisely mapped in world-first research to test the conservation value of areas closed to commercial fishing. Scientists from the CSIRO Wealth from Oceans National Research Flagship recently fitted acoustic tags to 50 gulper sharks, swellsharks and green eye dogfish near Port Lincoln, South Australia.

Insects Evolved Radically Different Strategy To Smell:

Darwin’s tree of life represents the path and estimates the time evolution took to get to the current diversity of life. Now, new findings suggest that this tree, an icon of evolution, may need to be redrawn. In research to be published in the April 13 advance online issue of Nature, researchers at Rockefeller University and the University of Tokyo have joined forces to reveal that insects have adopted a strategy to detect odors that is radically different from those of other organisms — an unexpected and controversial finding that may dissolve a dominant ideology in the field.

Fly Is At Home On A Crab, With New Evolutionary Neighbors:

Scientists at the Max Planck Institute for Chemical Ecology, Germany, have rediscovered Drosophila endobranchia, a fly living in the mouth of land crabs. The members of Drosophilidae, a family consisting of about 3000 species, are often referred to as fruit flies although most of the members feed on microbes. As microbes can be found growing on a wide range of substrates, fruit flies can accordingly also be found in a multitude of habitats.

Sleep, Baby, Sleep: Parents’ Behavior Has Direct Impact On Children’s Sleep Problems:

Parents who want their babies to sleep through the night would be wise to avoid co-sleeping arrangements or feeding their children evening snacks beyond early infancy. According to a Université de Montréal study the way parents put their babies to bed has a direct impact on how well children sleep when they reach four to six years old.

Shorebird Numbers Crash In Australia:

One of the world’s great wildlife spectacles is under way across Australia: as many as two million migratory shorebirds of 36 species are gathering around Broome before an amazing 10,000-kilometre annual flight to their northern hemisphere breeding grounds. But an alarming new study has revealed that both these migrants and Australia’s one million resident shorebirds have suffered a massive collapse in numbers over the past 25 years.

Shift Work Linked To Organ Disease, Study Suggests:

Disruption of an individual’s natural sleep-wake cycle has been determined to be a contributing factor in the development of organ disease. The findings of U of T researchers were recently published in the Journal of American Physiology.

Mass Media Campaigns Can Convince Young Adults To Adopt Safer Sex Practices, Study Shows:

— Two University of Kentucky researchers from the department of communication in the UK College of Communications and Information Studies have learned that targeted mass media campaigns alone can be effective in convincing high sensation-seeking, impulsive decision-making young adults to adopt safer sex practices.

Wireless EEG System Self-powered By Body Heat And Light:

The Interuniversity Microelectronics Centre, affiliated with the Holst Centre, has developed a battery-free wireless 2-channel EEG* system powered by a hybrid power supply using body heat and ambient light which could be used to monitor brain waves after a head injury. The hybrid power supply combines a thermoelectric generator that uses the heat dissipated from a person’s temples and silicon photovoltaic cells. The entire system is wearable and integrated into a device resembling headphones. The system can provide more than 1mW on average indoor, which is more than enough for the targeted application.

Stress May Lead Students To Use Stimulants:

A growing number of high school and college students are turning to stimulants like ADHD drugs and energy drinks to help them through their stress — particularly during exam time. University of Michigan experts say that misuse of stimulants can lead to serious health consequences, and encourage parents to take steps toward preventing their children from overusing stimulants.

Anticipating A Laugh Reduces Our Stress Hormones, Study Shows:

In 2006 researchers investigating the interaction between the brain, behavior, and the immune system found that simply anticipating a mirthful laughter experience boosted health-protecting hormones. Now, two years later, the same researchers have found that the anticipation of a positive humorous laughter experience also reduces potentially detrimental stress hormones. According to Dr. Lee Berk, the study team’s lead researcher of Loma Linda University, Loma Linda, CA, “Our findings lead us to believe that by seeking out positive experiences that make us laugh we can do a lot with our physiology to stay well.”

Triple Threat: Young Macho Men With Serious Injuries Often Abuse Alcohol:

Men with serious injuries, such as traumatic brain injury or spinal cord injury, must deal with a range of emotions. If these men have strong traditional masculine ideas and abuse alcohol, it becomes even more difficult to help them heal and come to terms with their emotions and situations. A University of Missouri psychology researcher studied these challenging factors to find better ways to understand and treat men who fit this mold, such as the injured soldiers coming back from Iraq and Afghanistan.

Massive Study Of Madagascar Wildlife Leads To New Conservation Roadmap:

An international team of researchers has developed a remarkable new roadmap for finding and protecting the best remaining holdouts for thousands of rare species that live only in Madagascar, considered one of the most significant biodiversity hot spots in the world.

Flowers’ Fragrance Diminished By Air Pollution, Study Indicates:

Air pollution from power plants and automobiles is destroying the fragrance of flowers and thereby inhibiting the ability of pollinating insects to follow scent trails to their source, a new University of Virginia study indicates. This could partially explain why wild populations of some pollinators, particularly bees — which need nectar for food — are declining in several areas of the world, including California and the Netherlands.

The First Animal On Earth Was Significantly More Complex Than Previously Believed:

A new study mapping the evolutionary history of animals indicates that Earth’s first animal — a mysterious creature whose characteristics can only be inferred from fossils and studies of living animals–was probably significantly more complex than previously believed.

Playing Dead Works For Young FIre Ants Under Attack:

Pretending to be dead is an effective self-defense strategy adopted by young fire ant workers under attack from neighboring colonies. This tactic makes them four times more likely to survive aggression than older workers who fight back. As a result, these young workers are able to contribute to brood care and colony growth to ensure the survival and fitness of their queen.

Dr. Mom Was Right — And Wrong — About Washing Fruits And Vegetables:

Washing fresh fruits and vegetables before eating may reduce the risk of food poisoning and those awful episodes of vomiting and diarrhea. But washing alone — even with chlorine disinfectants — may not be enough, according to a new study by researchers in Pennsylvania.

Negligent, Attentive Mouse Mothers Show Biological Differences:

In mice, child neglect is a product of both nature and nurture, according to a new study.

Evolution In The Classroom: ‘Evolution Machine’ Lets Students See It Happen:

Evolution has taken another step away from being dismissed as “a theory” in the classroom, thanks to a new article in PLoS Biology. The research article, by Brian Paegel and Gerald Joyce of The Scripps Research Institute, California, documents the automation of evolution: they have produced a computer-controlled system that can drive the evolution of improved RNA enzymes–biological catalysts–without human input. In the future, this “evolution-machine” could feature in the classroom as well as the lab, allowing students to watch evolution happen in their biology lessons.

Migratory Birds Make Mistakes In Direction, But Not Distance:

Migratory birds make mistakes in terms of direction, but not distance. These are the findings of a team of ornithologists and ecologists from the University of Marburg, the Ornithological Society in Bavaria and the Helmholtz Centre for Environmental Research (UFZ), writing in the Journal of Ornithology. The scientists assessed several thousand reports of Asian birds from the leaf-warbler and thrush families that had strayed to Europe. They discovered that the distance between the breeding grounds in northern Siberia and the wintering sites in southern Asia was often similar to the distance between the breeding grounds and Europe. The more similar the distances and the more numerous a particular species, the higher the probability of this species of bird straying to Europe.

Discovery Of Link In Mosquito Mating Mechanism Could Lead To New Attack On Dengue And Yellow Fever:

Cornell researchers have identified a mating mechanism that possibly could be adapted to prevent female mosquitoes from spreading the viruses that cause dengue fever, second only to malaria as the most virulent mosquito-borne disease in the tropical world.

Just Like Penguins And Other Primates, People Trade Sex For Resources:

Female penguins mate with males who bring them pebbles to build egg nests. Hummingbirds mate to gain access to the most productive flowers guarded by larger males. New research shows that even affluent college students who don’t need resources will still attempt to trade sexual currency for provisions, said Daniel Kruger, research scientist at the University of Michigan School of Public Health.

There are 39 new articles in PLoS ONE this week – here are my picks and you go and look around for more:
The Cayman Crab Fly Revisited — Phylogeny and Biology of Drosophila endobranchia:

The majority of all known drosophilid flies feed on microbes. The wide spread of microorganisms consequently mean that drosophilids also can be found on a broad range of substrates. One of the more peculiar types of habitat is shown by three species of flies that have colonized land crabs. In spite of their intriguing lifestyle, the crab flies have remained poorly studied. Perhaps the least investigated of the three crab flies is the Cayman Island endemic Drosophila endobranchia. Apart from its life cycle very little is known about this species, including its phylogenetic position, which has remained unresolved due to a cryptic set of characteristics. Based on molecular data, corroborated by a re-analysis of the morphological make up, we have resolved the phylogenetic position of D. endobranchia and show that it somewhat surprisingly belongs to the large Neotropical repleta radiation, and should be considered as an aberrant member of the canalinea species group. Furthermore we also provide additional data on the behavior of these remarkable flies. Our findings reveal that the two Caribbean crab flies are not as distantly related as first thought, as both species are members of the derived repleta radiation. That this lineage has given rise to two species with the same odd type of breeding substrate is curious and prompts the question of what aspects of their shared ancestry has made these flies suitable for a life on (and inside) land crabs. Knowledge of the phylogenetic position of D. endobranchia will allow for comparative explorations and will aid in efforts aimed at understanding processes involved in drastic host shifts and extreme specialization.

Spatial Relational Memory Requires Hippocampal Adult Neurogenesis:

The dentate gyrus of the hippocampus is one of the few regions of the mammalian brain where new neurons are generated throughout adulthood. This adult neurogenesis has been proposed as a novel mechanism that mediates spatial memory. However, data showing a causal relationship between neurogenesis and spatial memory are controversial. Here, we developed an inducible transgenic strategy allowing specific ablation of adult-born hippocampal neurons. This resulted in an impairment of spatial relational memory, which supports a capacity for flexible, inferential memory expression. In contrast, less complex forms of spatial knowledge were unaltered. These findings demonstrate that adult-born neurons are necessary for complex forms of hippocampus-mediated learning.

An Information-Theoretic Analysis of Genetics, Gender and Age in Cancer Patients:

Germline genetics, gender and hormonal-signaling pathways are all well described modifiers of cancer risk and progression. Although an improved understanding of how germline genetic variants interact with other cancer risk factors may allow better prevention and treatment of human cancer, measuring and quantifying these interactions is challenging. In other areas of research, Information Theory has been used to quantitatively describe similar multivariate interactions. We implemented a novel information-theoretic analysis to measure the joint effect of a high frequency germline genetic variant of the p53 tumor suppressor pathway (MDM2 SNP309 T/G) and gender on clinical cancer phenotypes. This analysis quantitatively describes synergistic interactions among gender, the MDM2 SNP309 locus, and the age of onset of tumorigenesis in p53 mutation carriers. These results offer a molecular and genetic basis for the observed sexual dimorphism of cancer risk in p53 mutation carriers and a model is proposed that suggests a novel cancer prevention strategy for p53 mutation carriers.

Measles on the Edge: Coastal Heterogeneities and Infection Dynamics:

Mathematical models can help elucidate the spatio-temporal dynamics of epidemics as well as the impact of control measures. The gravity model for directly transmitted diseases is currently one of the most parsimonious models for spatial epidemic spread. This model uses distance-weighted, population size-dependent coupling to estimate host movement and disease incidence in metapopulations. The model captures overall measles dynamics in terms of underlying human movement in pre-vaccination England and Wales (previously established). In spatial models, edges often present a special challenge. Therefore, to test the model’s robustness, we analyzed gravity model incidence predictions for coastal cities in England and Wales. Results show that, although predictions are accurate for inland towns, they significantly underestimate coastal persistence. We examine incidence, outbreak seasonality, and public transportation records, to show that the model’s inaccuracies stem from an underestimation of total contacts per individual along the coast. We rescue this predicted ‘edge effect’ by increasing coastal contacts to approximate the number of per capita inland contacts. These results illustrate the impact of ‘edge effects’ on epidemic metapopulations in general and illustrate directions for the refinement of spatiotemporal epidemic models.

Bioethics Grows Up:

When I taught my first course in bioethics to first-year students at Columbia University’s College of Physicians and Surgeons in the spring semester of 1981, bioethics was still in its formative years. There were scant few textbooks around and even fewer anthologies, and I could not assume that any of my students had ever read anything by a bioethicist or about bioethics. The key institutions in the field at that time, the Hastings Center, then in Hastings-on-Hudson, New York, and the Kennedy Institute at Georgetown University in Washington, DC, were barely over a decade old, and only one journal devoted to bioethics had been publishing for a significant period of time. Most major medical and biomedical journals were wary of publishing pieces on ethics, because the editors did not think that articles on a soft and mushy subject such as ethics were appropriate for journals of medicine and science. An instructor in those days really had to scramble to find and assemble the best writings and be ready to incur a hefty Xeroxing bill.

Darwinian Evolution on a Chip:

The principles of Darwinian evolution are fundamental to understanding biological organization and have been applied to the development of functional molecules in the test tube. Laboratory evolution is greatly accelerated compared with natural evolution, but it usually requires substantial manipulation by the experimenter. Here we describe a system that relies on computer control and microfluidic chip technology to automate the directed evolution of functional molecules, subject to precisely defined parameters. We used a population of billions of RNA enzymes with RNA-joining activity, which were challenged to react in the presence of progressively lower concentrations of substrate. The enzymes that did react were amplified to produce progeny, which were challenged similarly. Whenever the population size reached a predetermined threshold, chip-based operations were executed to isolate a fraction of the population and mix it with fresh reagents. These steps were repeated automatically for 500 iterations of 10-fold exponential growth followed by 10-fold dilution. We observed evolution in real time as the population adapted to the imposed selection constraints and achieved progressively faster growth rates over time. Our microfluidic system allows us to perform Darwinian evolution experiments in much the same way that one would execute a computer program.

Rethinking Outreach: Teaching the Process of Science through Modeling:

There has been a recent call for undergraduate faculty to engage in “scientific teaching”–a way of active teaching that places equal emphasis on both the process of science and the facts of science [1]. We endorse this approach and believe that the Milwaukee School of Engineering (MSOE) SMART Team modeling program captures many of the principles of scientific teaching in a high school outreach program by exposing students to the “real world of science” as practiced in a local research lab. SMART Teams, which consist of a small group of high school students and their teacher, work with a local research lab to design and build a physical model of the protein that is the focus of the lab’s research. During this modeling project, the students learn that science is much more than just the facts documented in their textbooks. They see that science is a process whereby real people–undergraduates, graduate students, post-docs, and principal investigators–go about learning something about a molecular world invisible to the naked eye. And in the molecular biosciences, what they are learning can be pretty amazing. While experiencing the culture of a research lab, SMART Team students begin to imagine themselves in the roles of their scientist mentors.

How Quickly Can a Rat Perceive Novel Odors?:

Odor perception in mammals is a multistep process that begins when olfactory sensory neurons in the animal’s nose detect an odor molecule and then transmit that sensory information as an electrical signal to the brain. The first brain area to receive these signals is the olfactory bulb, where the sensory neurons end in small structures called glomeruli. Olfactory cues trigger complex patterns of activity both in the olfactory sensory neurons and in the glomeruli within the brain. How these complex patterns underlie an animal’s ability to sense and respond to odors remains obscure. In a new study, Daniel Wesson et al. shed light on how these early signals lead to odor perception and subsequent behavioral changes by investigating how quickly a rat can respond to a novel odor. The speed of response, they show, depends on how quickly the olfactory bulb receives neural information about such an odor from the sensory neurons.