Category Archives: Science News

Whales Descended From Tiny Deer-like Ancestors:

Hans Thewissen, Ph.D., Professor of the Department of Anatomy, Northeastern Ohio Universities Colleges of Medicine and Pharmacy (NEOUCOM), has announced the discovery of the missing link between whales and their four-footed ancestors.

Medical Myths Even Doctors Believ:

Indiana University School of Medicine researchers explored seven commonly held medical beliefs. selected seven medical beliefs, espoused by both physicians and members of the general public, for critical review. They then searched for evidence to support or refute each of these claims.

Fruit Flies Learn and Remember Better When Lacking One Receptor:

When fruit flies lack a receptor for the inhibitory neurotransmitter gamma aminobutyric acid (GABA), their ability to learn or remember is enhanced, the first time scientists have been able to induce this effect in the insects, said Baylor College of Medicine researchers in a report that appears in the journal Neuron.

Two New Species Of Soft Coral Discovered In Caribbean:

Two new species of soft corals were discovered during an October expedition to Saba Bank, Netherlands Antilles, the largest atoll in the Caribbean. Herman Wirshing, a graduate student from the University of Miami Rosenstiel School of Marine and Atmospheric Science’s Biology and Fisheries Division, joined leading coral reef experts from Texas A&M University-Corpus Christi (TAM-CC), and the Universidad de los Andes in Columbia, to help identify and quantify soft coral and crustacean species on the Bank.

Wildlife Corridor Gives Endangered Elephants In India Passage Between Reserves:

More than one thousand wild elephants have been given a right of passage today, with the safeguarding of a wildlife corridor that links two reserves in Karnataka, Southern India.

Variable Light Illuminates The Distribution Of Picophytoplankton:

Tiny photosynthetic plankton less than a millionth of a millimeter in diameter numerically dominate marine phytoplankton. Their photosynthesis uses light to drive carbon dioxide uptake, fueling the marine food web over vast areas of the oceans. A new study by post-doctoral researcher Dr Christophe Six and a team of scientists from MountAllison University, Sackville, New Brunswick, Canada, illuminates how the environment regulates the distributions of these ecologically important species.

Precise Role Of Seminal Proteins In Sustaining Post-mating Responses In Fruit Flies:

Successful reproduction is critical to pass genes to the next generation. In sexually reproducing organisms, sperm enter the female with seminal proteins that are vital for fertility.

Selection Of Successful Sperms Influenced By Female Grey Mouse Lemurs:

In grey mouse lemurs from the dry deciduous forests in western Madagascar each female is receptive for a single night per year. For male mouse lemurs this is a stressful time. The main question in a research project conducted by Nina Schwensow and Simone Sommer of the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin and their colleague Manfred Eberle from the Leibniz Institute for Primate Research in Göttingen was: What will happen during this special night?

Songbirds Offer Clues To Highly Practiced Motor Skills In Humans:

The melodious sound of a songbird may appear effortless, but his elocutions are actually the result of rigorous training undergone in youth and maintained throughout adulthood. His tune has virtually “crystallized” by maturity. The same control is seen in the motor performance of top athletes and musicians. Yet, subtle variations in highly practiced skills persist in both songbirds and humans. Now, scientists think they know why.

Thursday night is a good time to see what is new on PLoS Pathogens, Computational Biology, Genetics and Neglected Tropical Diseases. Here are my picks for the week:
Hemolytic C-Type Lectin CEL-III from Sea Cucumber Expressed in Transgenic Mosquitoes Impairs Malaria Parasite Development:

Malaria is arguably the most important vector-borne disease worldwide, affecting 300 million people and killing 1-2 million people every year. The lack of an effective vaccine and the emergence of the parasites’ resistance to many existing anti-malarial drugs have aggravated the situation. Clearly, development of novel strategies for control of the disease is urgently needed. Mosquitoes are obligatory vectors for the disease and inhibition of parasite development in the mosquito has considerable promise as a new approach in the fight against malaria. Based on recent advances in the genetic engineering of mosquitoes, the concept of generating genetically modified (GM) mosquitoes that hinder transmission by either killing or interfering with parasite development is a potential means of controlling the disease. To generate these GM mosquitoes, the authors focused on a unique lectin isolated from the sea cucumber, which has both hemolytic and cytotoxic activities, as an anti-parasite effector molecule. A transgenic mosquito expressing the lectin effectively caused erythrocyte lysis in the midgut after ingestion of an infectious blood meal and severely impaired parasite development. This laboratory-acquired finding may provide significant implications for future malaria control using GM mosquitoes refractory to the parasites.

Spike Correlations in a Songbird Agree with a Simple Markov Population Model:

To deal with the vast complexity of the brain and its many degrees of freedom, many reductionist methods have been designed that can be used to simplify neural interactions to just a few key underlying macroscopic variables. Despite these theoretical advances, even today relatively few population models have been subjected to stringent experimental tests. We explore whether second-order spike correlations measured in songbirds can be explained by single-neuron statistics and population dynamics, both reflecting hypotheses on network connectivity. We formulate a Markov population model with essentially two degrees of freedom and associated with different behavioral states of birds such as waking, singing, or sleeping. Excellent agreement between spike-train data and model is achieved, given a few connectivity assumptions that strengthen the view of a hierarchical organization of songbird motor networks. This work is an important demonstration that a broad range of neural activity patterns can be compatible at the population level with few underlying degrees of freedom.

Treatment of Helminth Co-Infection in Individuals with HIV-1: A Systematic Review of the Literature (see the synopsis: Helminth-HIV Coinfection: Should We Deworm?)

Does Time Slow In Crisis? No, Say Researchers:

In The Matrix, hero Neo wins his battles when time slows in the simulated world. In the real world, accident victims often report a similar slowing as they slide unavoidably into disaster. But can humans really experience events in slow motion?

Monkeys Can Perform Mental Addition:

Researchers at Duke University have demonstrated that monkeys have the ability to perform mental addition. In fact, monkeys performed about as well as college students given the same test.

Why Diving Marine Mammals Resist Brain Damage From Low Oxygen:

No human can survive longer than a few minutes underwater, and even a well-trained Olympic swimmer needs frequent gulps of air. Our brains need a constant supply of oxygen, particularly during exercise.

Why Do People Support Underdogs And Find Them So Appealing?:

In a series of studies, researchers from the University of South Florida tested the scope of people’s support for those who are expected to lose, seeking to understand why people are drawn to the Rocky Balboas and the Davids (versus Goliaths) of the world.

Sea Cucumber Protein Used To Inhibit Development Of Malaria Parasite:

Scientists have genetically engineered a mosquito to release a sea-cucumber protein into its gut which impairs the development of malaria parasites, according to new research. Researchers say this development is a step towards developing future methods of preventing the transmission of malaria.

There are 28 new articles published today in PLoS ONE. You know what to do: read, rate, comment, annotate and send trackbacks! My picks for this week:
Light Variability Illuminates Niche-Partitioning among Marine Picocyanobacteria:

Phytoplankton are an important part of food webs in the ocean, and produce much of the oxygen in the Earth’s atmosphere. Due to mixing of water columns in the sea, phytoplankton have to cope with huge changes in the amount of light reaching them. In this study, Six and colleagues found that two different species of phytoplankton have widely differing capacities for tolerating sudden changes in the amount of light reaching them. These findings therefore suggest a degree of niche differentiation amongst the species of phytoplankton studied.

Canine Population Structure: Assessment and Impact of Intra-Breed Stratification on SNP-Based Association Studies:

In canine genetics, the impact of population structure on whole genome association studies is typically addressed by sampling approximately equal numbers of cases and controls from dogs of a single breed, usually from the same country or geographic area. However one way to increase the power of genetic studies is to sample individuals of the same breed but from different geographic areas, with the expectation that independent meiotic events will have shortened the presumed ancestral haplotype around the mutation differently. Little is known, however, about genetic variation among dogs of the same breed collected from different geographic regions. In this report, we address the magnitude and impact of genetic diversity among common breeds sampled in the U.S. and Europe. The breeds selected, including the Rottweiler, Bernese mountain dog, flat-coated retriever, and golden retriever, share susceptibility to a class of soft tissue cancers typified by malignant histiocytosis in the Bernese mountain dog. We genotyped 722 SNPs at four unlinked loci (between 95 and 271 per locus) on canine chromosome 1 (CFA1). We showed that each population is characterized by distinct genetic diversity that can be correlated with breed history. When the breed studied has a reduced intra-breed diversity, the combination of dogs from international locations does not increase the rate of false positives and potentially increases the power of association studies. However, over-sampling cases from one geographic location is more likely to lead to false positive results in breeds with significant genetic diversity. These data provide new guidelines for association studies using purebred dogs that take into account population structure.

A High Quality Draft Consensus Sequence of the Genome of a Heterozygous Grapevine Variety:

Viticulture takes a major scientific step forward with this publication of a high quality draft of the Pinot Noir grape genome. Riccardo Velasco and colleagues from the Grapevine Genome Initiative used shotgun sequencing to tackle the 504.6 megabase sequence, uncovering 2 million single nucleotide polymorphisms in 87% of the 29,585 identified genes, many involved in disease resistance and terpenoid synthesis. They also show that a whole genome duplication produced at least ten of the nineteen chromosomes.

A Family of Chemoreceptors in Tribolium castaneum (Tenebrionidae: Coleoptera):

Chemoperception in invertebrates is mediated by a family of G-protein-coupled receptors (GPCR). To date nothing is known about the molecular mechanisms of chemoperception in coleopteran species. Recently the genome of Tribolium castaneum was sequenced for use as a model species for the Coleoptera. Using blast searches analyses of the T. castaneum genome with previously predicted amino acid sequences of insect chemoreceptor genes, a putative chemoreceptor family consisting of 62 gustatory receptors (Grs) and 26 olfactory receptors (Ors) was identified. The receptors have seven transmembrane domains (7TMs) and all belong to the GPCR receptor family. The expression of the T. castaneum chemoreceptor genes was investigated using quantification real- time RT-PCR and in situ whole mount RT-PCR analysis in the antennae, mouth parts, and prolegs of the adults and larvae. All of the predicted TcasGrs were expressed in the labium, maxillae, and prolegs of the adults but TcasGr13, 19, 28, 47, 62, 98, and 61 were not expressed in the prolegs. The TcasOrs were localized only in the antennae and not in any of the beetles gustatory organs with one exception; the TcasOr16 (like DmelOr83b), which was localized in the antennae, labium, and prolegs of the beetles. A group of six TcasGrs that presents a lineage with the sugar receptors subfamily in Drosophila melanogaster were localized in the lacinia of the Tribolium larvae. TcasGr1, 3, and 39, presented an ortholog to CO2 receptors in D. melanogaster and Anopheles gambiae was recorded. Low expression of almost all of the predicted chemoreceptor genes was observed in the head tissues that contain the brains and suboesophageal ganglion (SOG). These findings demonstrate the identification of a chemoreceptor family in Tribolium, which is evolutionarily related to other insect species.

Visual Feedback Is Not Necessary for the Learning of Novel Dynamics:

When learning to perform a novel sensorimotor task, humans integrate multi-modal sensory feedback such as vision and proprioception in order to make the appropriate adjustments to successfully complete the task. Sensory feedback is used both during movement to control and correct the current movement, and to update the feed-forward motor command for subsequent movements. Previous work has shown that adaptation to stable dynamics is possible without visual feedback. However, it is not clear to what degree visual information during movement contributes to this learning or whether it is essential to the development of an internal model or impedance controller. We examined the effects of the removal of visual feedback during movement on the learning of both stable and unstable dynamics in comparison with the case when both vision and proprioception are available. Subjects were able to learn to make smooth movements in both types of novel dynamics after learning with or without visual feedback. By examining the endpoint stiffness and force after learning it could be shown that subjects adapted to both types of dynamics in the same way whether they were provided with visual feedback of their trajectory or not. The main effects of visual feedback were to increase the success rate of movements, slightly straighten the path, and significantly reduce variability near the end of the movement. These findings suggest that visual feedback of the hand during movement is not necessary for the adaptation to either stable or unstable novel dynamics. Instead vision appears to be used to fine-tune corrections of hand trajectory at the end of reaching movements.

Global Climate Change: The Impact Of El Niño On Galápagos Marine Iguanas:

A before-and-after study led by Yale biologists, of the effects of 1997 El Niño on the genetic diversity of marine iguanas on the Galápagos Islands, emphasizes the importance of studying populations over time and the need to determine which environmental and biological factors make specific populations more vulnerable than others.

Evolution With A Restricted Number Of Genes:

The development of higher forms of life would appear to have been influenced by RNA polymerase II. This enzyme transcribes the information coded by genes from DNA into messenger-RNA (mRNA), which in turn is the basis for the production of proteins. RNA polymerase II is highly conserved through evolution, with many of its structural characteristics being conserved between bacteria and humans.

Wild Chimpanzees Appear Not To Regularly Experience Menopause:

A pioneering study of wild chimpanzees has found that these close human relatives do not routinely experience menopause, rebutting previous studies of captive individuals which had postulated that female chimpanzees reach reproductive senescence at 35 to 40 years of age.

How Plants Control The Size of Leaves and Flowers:

The beauty of nature is partly due to the uniformity of leaf and flower size in individual plants, and scientists have discovered how plants arrive at these aesthetic proportions. Researchers at the John Innes Centre in Norwich have discovered that cells at the margins of leaves and petals play a particularly important role in setting their size.

Basic Math in Monkeys and College Students:

Adult humans possess mathematical abilities that are unmatched by any other member of the animal kingdom. Yet, there is increasing evidence that the ability to enumerate sets of objects nonverbally is a capacity that humans share with other animal species. That is, like humans, nonhuman animals possess the ability to estimate and compare numerical values nonverbally. We asked whether humans and nonhuman animals also share a capacity for nonverbal arithmetic. We tested monkeys and college students on a nonverbal arithmetic task in which they had to add the numerical values of two sets of dots together and choose a stimulus from two options that reflected the arithmetic sum of the two sets. Our results indicate that monkeys perform approximate mental addition in a manner that is remarkably similar to the performance of the college students. These findings support the argument that humans and nonhuman primates share a cognitive system for nonverbal arithmetic, which likely reflects an evolutionary link in their cognitive abilities.

New Hope For Sleep Disorders: Genetic Switch For Circadian Rhythms Discovered:

University of California, Irvine researchers have identified the chemical switch that triggers the genetic mechanism regulating our internal body clock. The finding, which uncovers the most specific information about the body’s circadian rhythms to date, identifies a precise target for new pharmaceuticals that can treat sleep disorders and a host of related ailments. Paolo Sassone-Corsi, Distinguished Professor and Chair of Pharmacology, found that a single amino acid activates the genes that regulate circadian rhythms. Amino acids are the building blocks of proteins, and Sassone-Corsi was surprised to find that only a single amino acid activates the body-clock mechanism because of the complex genes involved.

Skin Color Evolution In Fish And Humans Determined By Same Genetic Machinery:

When humans began to migrate out of Africa about 100,000 years ago, their skin color gradually changed to adapt to their new environments. And when the last Ice Age ended about 10,000 years ago, marine ancestors of ocean-dwelling stickleback fish experienced dramatic changes in skin coloring as they colonized newly formed lakes and streams. New research shows that despite the vast evolutionary gulf between humans and the three-spined stickleback fish, the two species have adopted a common genetic strategy to acquire the skin pigmentation that would help each species thrive in their new environments.

Ape To Human: Walking Upright May Have Protected Heavy Human Babies:

The transition from apes to humans may have been partially triggered by the need to stand on two legs, in order to safely carry heavier babies. This theory of species evolution presented by Lia Amaral from the University of São Paulo in Brazil has just been published online in Springer’s journal, Naturwissenschaften.

Two New Mammal Species Discovered In Indonesia’s Wilderness:

A tiny possum and a giant rat were recorded by scientists as probable new species on a recent expedition to Indonesia’s remote and virtually unknown “Lost World” in the pristine wilderness of western New Guinea’s Foja Mountains. The Foja Wilderness is part of the great Mamberamo Basin, the largest unroaded tropical forest in the Asia Pacific region.

Emerging Field Of Neuroecology Bridges Neural Basis Of Behavior And Ecological Consequences:

Neuroecology bridges a critical gap between studying the neural basis of behavior (neuroethology) and evaluating the consequences of that behavior at the ecological levels of populations and communities. A plant laces its leaves with a noxious chemical, forcing a hungry herbivore to choose between starving, eating a potentially toxic item, or moving on. A newt secretes a potent neurotoxin to defend against predators, unwittingly setting off a cascade of effects in its freshwater pond, where other inhabitants co-opt the toxin for different uses. A squid escapes a predator by clouding the water with ink — but is this a visual defense, or are there chemical implications for the ecosystem as well?

Predicting Growth Hormone Treatment Success:

Growth hormone treatments work better on some children than on others, but judging which candidates will gain those vital inches in height is no simple task. Now researchers have developed a new mathematical model which predicts the optimal dose of growth hormone to treat children who are abnormally short for a wide range of reasons. A new study describes a model that can be more widely applied than previous versions, with greater predictive accuracy.

New Research Alters Concept Of How Circadian Clock Functions:

Scientists from the University of Cambridge have identified a molecule that may govern how the circadian clock in plants responds to environmental changes. The researchers have discovered that a signalling molecule, known to be important for environmental stress signalling in plants, also regulates their circadian clock. They believe that the molecule may therefore incorporate information about environmental changes into the biological clock that regulates the physiology of plants. The research dramatically changes our current understanding of the circadian clock and may have important implications for the agricultural community.

Penguins In Peril As Climate Warms:

The penguin population of Antarctica is under pressure from global warming, according to a WWF report. The report, Antarctic Penguins and Climate Change, shows that the four populations of penguins that breed on the Antarctic continent — Adélie, Emperor, Chinstrap and Gentoo — are under escalating pressure. For some, global warming is taking away precious ground on which penguins raise their young. For others, food has become increasingly scarce because of warming in conjunction with overfishing.

To Catch A Panda:

Michigan State University’s panda habitat research team has spent years collecting mountains of data aimed at understanding and saving giant pandas. Now a graduate student is working to catch crucial data that’s black, white and furry. Vanessa Hull, 25, a Ph.D. candidate, is in the snowy, remote mountains of the Sichuan Province of China — which also is the heart of panda habitat. She’s hoping to capture, collar and track up to four wild pandas using advanced global positioning systems.

New, Rare And Threatened Species Discovered In Ghana:

Scientists exploring one of the largest remaining blocks of tropical forest in Western Africa discovered significant populations of new, rare and threatened species underscoring the area’s high biological diversity and value.

Genetic Differences Influence Aging Rates In The Wild:

Long-lived, wild animals harbor genetic differences that influence how quickly they begin to show their age, according to the results of a long-term study. Evidence for the existence of such genetic variation for aging rates–a central tenet in the evolutionary theory that explains why animals would show physiological declines as they grow older–had largely been lacking in natural populations until now, the researchers said.

Losses Of Long-established Genes Contribute To Human Evolution

While it is well understood that the evolution of new genes leads to adaptations that help species survive, gene loss may also afford a selective advantage. A group of scientists at the University of California, Santa Cruz led by biomolecular engineering professor David Haussler has investigated this less-studied idea, carrying out the first systematic computational analysis to identify long-established genes that have been lost across millions of years of evolution leading to the human species.

The actual paper is here
Cholesterol Fine Tunes Hearing:

Levels of cholesterol in the membranes of hair cells in the inner ear can affect your hearing, said a consortium of researchers from Baylor College of Medicine, Rice University and Purdue University in a new report in the Journal of Biological Chemistry.

Anti-drinking Campaign Ads May Be ‘Catastrophically Misconceived’:

Some anti-drinking advertising campaigns may be “catastrophically misconceived” because they play on the entertaining ‘drinking stories’ that young people use to mark their social identity, say researchers who have just completed a three year study of the subject.

Intensive Care Quality Of Sleep Improved By New Drug, Reports Study:

A new sedative drug has been shown to improve the sleep quality and comfort levels of intensive care patients, compared to the most commonly-used medication, according to research published in the journal JAMA.

On Fridays I look at the new stuff published on PLoS community journals, i.e., PLoS Pathogens, Neglected Tropical Diseases, Genetics and Computational Biology. Here are my picks for this week:
The Per2 Negative Feedback Loop Sets the Period in the Mammalian Circadian Clock Mechanism:

Network models of biological systems are appearing at an increasing rate. By encapsulating mechanistic detail of chemical and physical processes, mathematical models can successfully simulate and predict emergent network properties. However, methods are needed for analyzing the role played by individual biochemical steps in producing context-dependent system behavior, thereby linking individual molecular knowledge with network properties. Here, we apply sensitivity analysis to analyze mammalian circadian rhythms and find that a contiguous series of reactions in one of the four negative feedback loops carries primary responsibility for determining the intrinsic length of day. The key reactions, all involving the gene per2 and its products, include Per2 mRNA export and degradation, and PER2 phosphorylation, transcription, and translation. Interestingly, mutations affecting PER2 phosphorylation have previously been linked to circadian disorders. The method may be generally applicable to probe structure-function relationships in biological networks.

Sustained Post-Mating Response in Drosophila melanogaster Requires Multiple Seminal Fluid Proteins:

In sexually reproducing organisms, sperm enter the female in combination with seminal proteins that are critical for fertility. These proteins can activate sperm or enhance sperm storage within the female, and can improve the chance that sperm will fertilize eggs. Understanding the action of seminal proteins has potential utility in insect pest control and in the diagnosis of certain human infertilities. However, the precise function of very few seminal proteins is known. To address this, we knocked down the levels of 25 seminal proteins individually in male fruit flies, and tested the males’ abilities to modulate egg production, sperm storage/release, or behavior of their mates. We found five seminal proteins that are necessary to elevate offspring production in mated females. Four of these proteins are needed for efficient release of sperm from storage to fertilize eggs, a function that had not been previously assigned to any seminal protein. All four are in biochemical classes that are conserved in seminal fluid from insects to humans, suggesting they may play similar sperm-related roles in other animals. In addition to assigning functions to particular seminal proteins, our results suggest that fruit flies can serve as a model with which to dissect the functions of conserved protein classes in seminal fluid.

A Bacterial Kind of Aging:

Bacteria are sometimes honored with a few lines in books and reviews on aging as an example of organisms that do not age. This is because binary fission of bacteria has been assumed to proceed with a nonconservative dispersion of both undamaged and damaged constituents, such that there are no adult forms of bacterial cells and the bacterial population is not age structured. However, some authors have expressed different views; for example, Partridge and Barton [1] consider asymmetry in simple unicellular systems and how this might develop into aging, and Tom Kirkwood [2] argues, on theoretical grounds, that damage segregation could be selected for in simple unicellular systems dividing by binary fission, and that sibling-specific deterioration may confer a selective advantage. Indeed, recent reports lend experimental support to this notion and point to mandatory aging also being a part of the life history of bacteria.

Blind Humans Lacking Rods And Cones Retain Normal Responses To Non-visual Effects Of Light:

In addition to allowing us to see, the mammalian eye also detects light for a number of “non-visual” phenomena. A prime example of this is the timing of the sleep/wake cycle, which is synchronized by the effects of light on the circadian pacemaker in the hypothalamus. Researchers have identified two totally blind humans whose non-visual responses to light remain intact, suggesting that visual and non-visual responses to light are functionally distinct. Indeed, this separation was suggested by earlier studies in mice that demonstrated that circadian rhythms and other non-visual responses remain sensitive to light in the absence of rods and cones, the two photoreceptor types that are responsible for vision.

Related: Compared to your pet iguana, you are practically blind
Melanopsin
Semen Ingredient ‘Drastically’ Enhances HIV Infection:

A plentiful ingredient found in human semen drastically enhances the ability of the human immunodeficiency virus (HIV) to cause infection, according to a report in the December 14, 2007, issue of the journal Cell. The findings help to understand the sexual transmission of HIV and suggest a potential new target for preventing the spread of AIDS, the researchers said.

Mom’s Personality Means Survival For Her Squirrel Pups:

A recent study indicates that mother squirrels have personalities, and they are essential for the growth rate and survival of her pups. Researchers at the Kluane Red Squirrel Project found that red squirrels have a range of personalities, from exploratory and aggressive to careful and passive. Both kinds of squirrels persist in the population because neither personality type offers an exclusive advantage for survival.

Andean Highlands In Chile Yield Ancient South American Armored Mammal Fossil:

A paleontological dig in Chile at an altitude of more than 14,000 feet in the Andes has yielded fossils of an 18-million-year-old armored mammal. It appears to be one of the most primitive members of a family of extinct mammals known as “glyptodonts,” a group closely related to the modern-day armadillo.

Present-day Species Of Piranha Resulted From Marine Incursion Into Amazon Basin:

Piranhas inhabit exclusively the fresh waters of South America. Their geographical distribution extends from the Orinoco River basin (Venezuela) to the North, down to that of the Paraná (Argentina) to the South. Over this whole area, which also embraces the entire Amazon Basin, biologists have recorded 28 carnivorous species of these fish (2). In spite of the evolutionary success of this subfamily of fish, the mechanisms that generated the species richness of this group are still insufficiently known.

Massive Dinosaur Discovered In Antarctica Sheds Light On Life, Distribution Of Sauropodomorphs:

A new genus and species of dinosaur from the Early Jurassic has been discovered in Antarctica. The massive plant-eating primitive sauropodomorph is called Glacialisaurus hammeri and lived about 190 million years ago.

Aging In Salmon Depends On Choosy Bears:

According to George Bernard Shaw: “We don’t stop playing because we grow old; we grow old because we stop playing.” But how fast does that aging occur once started? In the case of populations of salmon in Alaska studied by Stephanie Carlson and colleagues at the University of Washington and McGill University and reported on in this week’s PLoS ONE, it all depends on how choosy are the bears which feed on them.

When She’s Turned On, Some Of Her Genes Turn Off, Fish Study Shows:

When a female is attracted to a male, entire suites of genes in her brain turn on and off, show biologists from The University of Texas at Austin studying swordtail fish.

The Effect Of ‘In Your Face’ Political Television On Democracy:

Television can encourage awareness of political perspectives among Americans, but the incivility and close-up camera angles that characterize much of today’s “in your face” televised political debate also causes audiences to react more emotionally and think of opposing views as less legitimate.

Different Areas Of The Brain Respond To Belief, Disbelief And Uncertainty:

The human mind is a prolific generator of beliefs about the world. The capacity of our minds to believe or disbelieve linguistic propositions is a powerful force for controlling both behavior and emotion, but the basis of this process in the brain is not yet understood.

There are 30 new articles published in PLoS ONE today. My personal picks:
Genetic Impact of a Severe El Nino Event on Galápagos Marine Iguanas (Amblyrhynchus cristatus):

El Nino is an ocean-atmosphere phenomenon occurring in the Pacific Basin which is responsible for extreme climate variation in the Southern hemisphere. In this study, the authors investigated whether a severe El Nino event affected the genetic make-up of Galapagos marine iguanas. No strong influence of El Nino on genetic diversity in the iguana populations was uncovered; however, the data suggest that future studies of this type also need to consider the potential effect of other biological and environmental changes on genetic diversity.

What Are You Feeling? Using Functional Magnetic Resonance Imaging to Assess the Modulation of Sensory and Affective Responses during Empathy for Pain:

Previous research suggests that empathy for pain activates similar pathways in the brain as first-hand painful experiences. However, the extent of similarity between empathy for pain and experienced pain is thought to depend on social factors and personality traits. Here, Lamm and colleagues studied the brain activity of participants who were shown photographs depicting painful or non-painful procedures on the hand of another participant. The results demonstrate that through emotional and bodily awareness people are able to evaluate the sensory and affective states of others.

Predation by Bears Drives Senescence in Natural Populations of Salmon:

Pacific salmon do not feed during their breeding period; they physically deteriorate very quickly once they start breeding and then die several weeks later. In this population-based study, the authors studied salmon and brown bears in southwest Alaska to find out whether the rate of aging in salmon was driven primarily by the rate of predation by bears, or by the tendency of the bears to prey on salmon with less evidence of aging. The results show that the main factor affecting the rate of aging in salmon populations was the tendency of bears to choose salmon with less evidence of aging.

Cross-Attraction between an Exotic and a Native Pine Bark Beetle: A Novel Invasion Mechanism?:

Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain invasiveness of pests. Here, we present information on a recently formed association between a native and an exotic bark beetle on their shared host, Pinus tabuliformis, in China. In field examinations, we found that 35-40% of P. tabuliformis attacked by an exotic bark beetle, Dendroctonus valens, were also attacked by a native pine bark beetle, Hylastes parallelus. In the laboratory, we found that the antennal and walking responses of H. parallelus to host- and beetle-produced compounds were similar to those of the exotic D. valens in China. In addition, D. valens was attracted to volatiles produced by the native H. parallelus. We report, for the first time, facilitation between an exotic and a native bark beetle seems to involve overlap in the use of host attractants and pheromones, which is cross-attraction. The concept of this interspecific facilitation could be explored as a novel invasive mechanism which helps explain invasiveness of not only exotic bark beetles but also other introduced pests in principle. The results reported here also have particularly important implications for risk assessments and management strategies for invasive species.

Increased Litterfall in Tropical Forests Boosts the Transfer of Soil CO2 to the Atmosphere:

Aboveground litter production in forests is likely to increase as a consequence of elevated atmospheric carbon dioxide (CO2) concentrations, rising temperatures, and shifting rainfall patterns. As litterfall represents a major flux of carbon from vegetation to soil, changes in litter inputs are likely to have wide-reaching consequences for soil carbon dynamics. Such disturbances to the carbon balance may be particularly important in the tropics because tropical forests store almost 30% of the global soil carbon, making them a critical component of the global carbon cycle; nevertheless, the effects of increasing aboveground litter production on belowground carbon dynamics are poorly understood. We used long-term, large-scale monthly litter removal and addition treatments in a lowland tropical forest to assess the consequences of increased litterfall on belowground CO2 production. Over the second to the fifth year of treatments, litter addition increased soil respiration more than litter removal decreased it; soil respiration was on average 20% lower in the litter removal and 43% higher in the litter addition treatment compared to the controls but litter addition did not change microbial biomass. We predicted a 9% increase in soil respiration in the litter addition plots, based on the 20% decrease in the litter removal plots and an 11% reduction due to lower fine root biomass in the litter addition plots. The 43% measured increase in soil respiration was therefore 34% higher than predicted and it is possible that this ‘extra’ CO2 was a result of priming effects, i.e. stimulation of the decomposition of older soil organic matter by the addition of fresh organic matter. Our results show that increases in aboveground litter production as a result of global change have the potential to cause considerable losses of soil carbon to the atmosphere in tropical forests.

A Novel Interhemispheric Interaction: Modulation of Neuronal Cooperativity in the Visual Areas:

The cortical representation of the visual field is split along the vertical midline, with the left and the right hemi-fields projecting to separate hemispheres. Connections between the visual areas of the two hemispheres are abundant near the representation of the visual midline. It was suggested that they re-establish the functional continuity of the visual field by controlling the dynamics of the responses in the two hemispheres. To understand if and how the interactions between the two hemispheres participate in processing visual stimuli, the synchronization of responses to identical or different moving gratings in the two hemi-fields were studied in anesthetized ferrets. The responses were recorded by multiple electrodes in the primary visual areas and the synchronization of local field potentials across the electrodes were analyzed with a recent method derived from dynamical system theory. Inactivating the visual areas of one hemisphere modulated the synchronization of the stimulus-driven activity in the other hemisphere. The modulation was stimulus-specific and was consistent with the fine morphology of callosal axons in particular with the spatio-temporal pattern of activity that axonal geometry can generate. These findings describe a new kind of interaction between the cerebral hemispheres and highlight the role of axonal geometry in modulating aspects of cortical dynamics responsible for stimulus detection and/or categorization.

What Causes Partial F1 Hybrid Viability? Incomplete Penetrance versus Genetic Variation:

Interspecific hybrid crosses often produce offspring with reduced but non-zero survivorship. In this paper we ask why such partial inviability occurs. This partial inviability could arise from incomplete penetrance of lethal Dobzhansky-Muller incompatibilities (DMIs) shared by all members of a hybrid cross. Alternatively, siblings may differ with respect to the presence or number of DMIs, leading to genotype-dependent variation in viability and hence non-Mendelian segregation of parental alleles in surviving F1 hybrids. We used amplified fragment length polymorphisms (AFLPs) to test for segregation distortion in one hybrid cross between green and longear sunfish (Lepomis cyanellus and L. megalotis). Hybrids showed partial viability, and twice as much segregation distortion (36.8%) of AFLPs as an intraspecific control cross (18.8%). Incomplete penetrance of DMIs, which should cause genotype-independent mortality, is insufficient to explain the observed segregation distortion. We conclude that F1 hybrid sunfish are polymorphic for DMIs, either due to sex-linked DMI loci (causing Haldane’s Rule), or polymorphic autosomal DMI loci. Because few AFLP markers were sex-linked (2%), the most parsimonious conclusion is that parents may have been heterozygous for loci causing hybrid inviability.

Does Time Really Slow Down during a Frightening Event?:

Observers commonly report that time seems to have moved in slow motion during a life-threatening event. It is unknown whether this is a function of increased time resolution during the event, or instead an illusion of remembering an emotionally salient event. Using a hand-held device to measure speed of visual perception, participants experienced free fall for 31 m before landing safely in a net. We found no evidence of increased temporal resolution, in apparent conflict with the fact that participants retrospectively estimated their own fall to last 36% longer than others’ falls. The duration dilation during a frightening event, and the lack of concomitant increase in temporal resolution, indicate that subjective time is not a single entity that speeds or slows, but instead is composed of separable subcomponents. Our findings suggest that time-slowing is a function of recollection, not perception: a richer encoding of memory may cause a salient event to appear, retrospectively, as though it lasted longer.

Researchers Can Read Thoughts To Decipher What A Person Is Actually Seeing:

Following ground-breaking research showing that neurons in the human brain respond in an abstract manner to particular individuals or objects, University of Leicester researchers have now discovered that, from the firing of this type of neuron, they can tell what a person is actually seeing.

Are Humans Evolving Faster? Findings Suggest We Are Becoming More Different, Not Alike:

Researchers have discovered genetic evidence that human evolution is speeding up — and has not halted or proceeded at a constant rate, as had been thought — indicating that humans on different continents are becoming increasingly different.

Eating More Red And Processed Meats Linked To Greater Risk For Bowel And Lung Cancer, Findings Suggest:

New findings provide evidence that people who eat a lot of red and processed meats have greater risk of developing bowel and lung cancer than people who eat small quantities. The research by Amanda Cross and colleagues at the US National Cancer Institute is published in the latest issue of PLoS Medicine.

For The Fruit Fly, Everything Changes After Sex:

Barry Dickson, director of the Research Institute of Molecular Pathology (IMP) in Austria, and his group are interested in the genetic basis of innate behaviour. They focus on the reproductive behaviour of the fruit fly Drosophila melanogaster. Two years ago, the team was able to identify the fruitless gene as a key regulator of mating behaviour.

Threatened Birds May Be Rarer Than Geographic Range Maps Suggest:

Geographic range maps that allow conservationists to estimate the distribution of birds may vastly overestimate the actual population size of threatened species and those with specific habitats, according to a study published online this week in the journal Conservation Biology.

On Monday nights, it is time to see what is new in PLoS Medicine and PLoS Biology:
Meat Consumption and Cancer Risk:

Meat consumption in relation to cancer risk has been reported in over a hundred epidemiological studies from many countries with diverse diets. The association between meat intake and cancer risk has been evaluated by looking both at broad groupings of total meat intake, and also at finer categorizations, particularly intakes of red meat, which includes beef, lamb, pork, and veal, and also more specifically processed meats, which includes meats preserved by salting, smoking, or curing.

A Prospective Study of Red and Processed Meat Intake in Relation to Cancer Risk:

Background.
Every year, there are more than 10 million new cases of cancer around the world. These cases are not spread evenly across the globe. The annual incidence of cancer (the number of new cases divided by the population size) and the type of cancer most commonly diagnosed varies widely among countries. Much of the global variation in cancer incidence and type is thought to be due to environmental influences. These include exposure to agents in the air or water that cause cancer, and lifestyle factors such as smoking and diet. Researchers identify environmental factors that affect cancer risk by measuring the exposure of a large number of individuals to a specific environmental factor and then monitoring these people for several years to see who develops cancer. The hope is that by identifying the environmental factors that cause or prevent cancer, the global burden of cancer can be reduced.
Why Was This Study Done?
Diet is thought to influence the incidence of several cancers but it is very difficult to unravel which aspects of diet are important. Being overweight, for example, is strongly associated with an increased risk of developing several types of cancer, but the evidence that the intake of red meat (beef, pork, and lamb) and of processed meat (for example, bacon, ham, and sausages) is linked to cancer risk is much weaker. Although several studies have linked a high intake of red meat and processed meat to an increased risk of colorectal cancer (the colon is the large bowel; the rectum is the final few inches of the large bowel before the anus), whether this aspect of diet affects the risk of other types of cancer is unclear. In this prospective study, the researchers have examined the association between meat intake and the incidence of a wide range of cancers.
What Did the Researchers Do and Find?
In 1995-1996, nearly half a million US men and women aged 50-71 y joined the NIH-AARP Diet and Health Study. The participants in this study–none of whom had had cancer previously–completed a questionnaire about their dietary habits over the previous year and provided other personal information such as their age, weight, and smoking history. The researchers used these data and information from state cancer registries to look for associations between the intake of red and processed meat and the incidence of various cancers. They found that people whose red meat intake was in the top fifth of the range of intakes recorded in the study (the highest quintile of consumption) had an increased risk of developing colorectal, liver, lung, and esophageal cancer when compared with people in the lowest quintile of consumption. People in the highest quintile of processed meat intake had an increased risk of developing colorectal and lung cancer. The incidences of other cancers were largely unaffected by meat intake.
What Do These Findings Mean?
These findings provide strong evidence that people who eat a lot of red and processed meats have greater risk of developing colorectal and lung cancer than do people who eat small quantities. They also indicate that a high red meat intake is associated with an increased risk of esophageal and liver cancer, and that one in ten colorectal and one in ten lung cancers could be avoided if people reduced their red and processed meat intake to the lowest quintile. However, although the researchers allowed for factors such as smoking history that might have affected cancer incidences, some of the effects they ascribe to meat intake might be caused by other lifestyle factors. Furthermore, because the study’s definitions of red meat and processed meat overlapped–bacon and ham, for example, were included in both categories–exactly which type of meat is related to cancer remains unclear. Finally, most of the study participants were non-Hispanic white, so these findings may not apply to people with different genetic backgrounds. Nevertheless, they add to the evidence that suggests that decreased consumption of red and processed meats could reduce the incidence of several types of cancer.

Improving Science Education for Sustainable Development:

In recent issues of noteworthy journals, natural scientists have argued for the improvement of science education. Such pleas reflect the growing awareness that high-quality science education is required not only for sustaining a lively scientific community that is able to address global problems like global warming and pandemics, but also to bring about and maintain a high level of scientific literacy in the general population. There is no doubt that effective education can serve as a vehicle for solving global problems. The problem centers on how to achieve more effective education.

Generosity May Be Genetically Programmed:

Are those inclined towards generosity genetically programmed to behave that way? A team of researchers, including Dr. Ariel Knafo of the Psychology Department at the Hebrew University of Jerusalem, believes that this could very well be the case.

Like Humans, Monkey See, Monkey Plan, Monkey Do:

How many times a day do you grab objects such as a pencil or a cup? We perform these tasks without thinking, however the motor planning necessary to grasp an object is quite complex. The way human adults grasp objects is typically influenced more by their knowledge of what they intend to do with the objects than the objects’ immediate appearance. Psychologists call this the “end-state comfort effect,” when we adopt initially unusual, and perhaps uncomfortable, postures to make it easier to actually use an object.

In Fruit Flies, Homosexuality Is Biological But Not Hard-wired, Study Shows:

While the biological basis for homosexuality remains a mystery, a team of neurobiologists reports they may have closed in on an answer — by a nose.

Bacteria Employ Type Of DNA Modification Never Before Seen In Nature:

A team of MIT researchers and others has discovered that bacteria employ a type of DNA modification never before seen in nature.

‘Smart’ Flower Bulbs Pull Themselves To Deeper Ground:

Confused about the right planting depth for flower bulbs? Trust the bulbs! Researchers have discovered that some flower bulbs are actually “smart” enough to adjust themselves to the right planting depth. A recent study published in the Journal of the American Society for Horticultural Science proved that bulbs can adjust their planting position by moving deeper into the ground, apparently in search of moister, more conducive growing conditions.

Young Chimps Top Adult Humans In Numerical Memory:

Young chimpanzees have an “extraordinary” ability to remember numerals that is superior to that of human adults, researchers report.

Artificial Jellyfish, Explosives Sensor Among Projects Being Developed At Undersea Technology Center:

Artificial jellyfish, explosives sensors and seabed batteries are among the diverse research projects under way just nine months after the creation of a Center of Excellence in Undersea Technology in collaboration with the Naval Undersea Warfare Center in Rhode Island.

Heads Or Tails? Scientists Identify Gene That Regulates Polarity In Regenerating Flatworms:

When cut, a planarian flatworm can use a population of stem cells called neoblasts to regenerate new heads, new tails or even entire new organisms from a tiny fragment of its body. Mechanisms have been sought to explain this process of regeneration polarity for over 100 years, but until now, little was known about how planaria can regenerate heads and tails at their proper sites.

Each week, there are new articles published in PLoS Neglected Tropical Diseases, Pathogens, Computational Biology and Genetics. Check them out. Today’s pick:
The Role of Carcinine in Signaling at the Drosophila Photoreceptor Synapse:

During signaling in the nervous system, individual nerve cells transfer information to one another by a complex process called synaptic transmission. This communication involves the release of a specific neurotransmitter into the synaptic cleft, which then triggers signaling in the downstream neuron by binding to and activating specific cell surface receptors. In order to terminate the neuronal signal, the neurotransmitter must be rapidly removed from the synaptic cleft. This is done by two mechanisms: the neurotransmitter can be degraded or modified, or the transmitter can be taken up by the presynaptic neuron and packaged into vesicles for reuse. In the compound eye of the fruitfly D. melanogaster, the photoreceptor cell responds to light and releases histamine into the synaptic cleft. This signal is terminated by the removal of histamine from the synapse and the enzymatic conversion of histamine to carcinine. We have shown that it is not sufficient just to modify the histamine neurotransmitter, but it is also important to remove carcinine from the photoreceptor synapse. The failure to adequately remove carcinine results in defects in the visual transduction process. Moreover, the work suggests that carcinine itself modulates vision by regulating histamine release into the synapse.

Humans Appear Hardwired To Learn By ‘Over-Imitation’:

Children learn by imitating adults–so much so that they will rethink how an object works if they observe an adult taking unnecessary steps when using that object, according to a new Yale study.

Subliminal Smells Bias Perception About A Person’s Likeability:

Anyone who has bonded with a puppy madly sniffing with affection gets an idea of how scents, most not apparent to humans, are critical to a dog’s appreciation of her two-legged friends. Now new research from Northwestern University suggests that humans also pick up infinitesimal scents that affect whether or not we like somebody.

Free Software Brings Affordability, Transparency To Mathematics:

Until recently, a student solving a calculus problem, a physicist modeling a galaxy or a mathematician studying a complex equation had to use powerful computer programs that cost hundreds or thousands of dollars. But an open-source tool based at the University of Washington won first prize in the scientific software division of Les Trophées du Libre, an international competition for free software.

Brain Systems Become Less Coordinated With Age, Even In The Absence Of Disease:

Some brain systems become less coordinated with age even in the absence of Alzheimer’s disease, according to a new study from Harvard University. The results help to explain why advanced age is often accompanied by a loss of mental agility, even in an otherwise healthy individual.

Pass The Popcorn! Study Finds That Film Enjoyment Is Contagious:

Loud commentary and cell phone fumbling may be distracting, but new research suggests that the presence of other people may enhance our movie-watching experiences. Over the course of the film, movie-watchers influence one another and gradually synchronize their emotional responses. This mutual mimicry also affects each participant’s evaluation of the overall experience — the more in sync we are with the people around us, the more we like the movie.

Optimism Isn’t Always Healthy:

People are generally optimistic, believing they’ll do better in the future than they’ve done in the past. This time around, I’ll actually use that gym membership. I’m sticking to the diet this time. Now is the time to start saving for a down payment on a house. However, a new study reveals that this “optimism bias” can lead us to make immediate choices that go against our long-term goals.

Fighting Diseases Of Aging By Wasting Energy, Rather Than Dieting — Works For Mice:

By making the skeletal muscles of mice use energy less efficiently, researchers report that they have delayed the animals’ deaths and their development of age-related diseases, including vascular disease, obesity, and one form of cancer. Those health benefits, driven by an increased metabolic rate, appear to come without any direct influence on the aging process itself, according to the researchers.

Gene Implicated In Human Language Affects Song Learning In Songbirds:

Do special “human” genes provide the biological substrate for uniquely human traits, like language?

Chipmunks And Shrews, Not Just Mice, Harbor Lyme Disease:

A study led by a University of Pennsylvania biologist in the tick-infested woods of the Hudson Valley is challenging the widely held belief that mice are the main animal reservoir for Lyme disease in the U.S.

Flies’ Evasive Move Traced To Sensory Neurons:

When fruit fly larvae are poked or prodded, they fold themselves up and corkscrew their bodies around, a behavior that appears to be the young insects’ equivalent of a “judo move,” say researchers. They now trace that rolling behavior to neurons resembling those that sense pain.

Pheromones Identified That Trigger Aggression Between Male Mice:

A family of proteins commonly found in mouse urine is able to trigger fighting between male mice, a new study has found. The study is the first to identify protein pheromones responsible for the aggression response in mice. Pheromones are chemical cues that are released into the air, secreted from glands, or excreted in urine and picked up by animals of the same species, initiating various social and reproductive behaviors.

Tuesday night – time to see what’s new in PLoS ONE – 28 new papers:
Reporting Science and Conflicts of Interest in the Lay Press:

Forthright reporting of financial ties and conflicts of interest of researchers is associated with public trust in and esteem for the scientific enterprise. We searched Lexis/Nexis Academic News for the top news stories in science published in 2004 and 2005. We conducted a content analysis of 1152 newspaper stories. Funders of the research were identified in 38% of stories, financial ties of the researchers were reported in 11% of stories, and 5% reported financial ties of sources quoted. Of 73 stories not reporting on financial ties, 27% had financial ties publicly disclosed in scholarly journals. Because science journalists often did not report conflict of interest information, adherence to gold-standard recommendations for science journalism was low. Journalists work under many different constraints, but nonetheless news reports of scientific research were incomplete, potentially eroding public trust in science.

Structure of the Scientific Community Modelling the Evolution of Resistance:

Faced with the recurrent evolution of resistance to pesticides and drugs, the scientific community has developed theoretical models aimed at identifying the main factors of this evolution and predicting the efficiency of resistance management strategies. The evolutionary forces considered by these models are generally similar for viruses, bacteria, fungi, plants or arthropods facing drugs or pesticides, so interaction between scientists working on different biological organisms would be expected. We tested this by analysing co-authorship and co-citation networks using a database of 187 articles published from 1977 to 2006 concerning models of resistance evolution to all major classes of pesticides and drugs. These analyses identified two main groups. One group, led by ecologists or agronomists, is interested in agricultural crop or stock pests and diseases. It mainly uses a population genetics approach to model the evolution of resistance to insecticidal proteins, insecticides, herbicides, antihelminthic drugs and miticides. By contrast, the other group, led by medical scientists, is interested in human parasites and mostly uses epidemiological models to study the evolution of resistance to antibiotic and antiviral drugs. Our analyses suggested that there is also a small scientific group focusing on resistance to antimalaria drugs, and which is only poorly connected with the two larger groups. The analysis of cited references indicates that each of the two large communities publishes its research in a different set of literature and has its own keystone references: citations with a large impact in one group are almost never cited by the other. We fear the lack of exchange between the two communities might slow progress concerning resistance evolution which is currently a major issue for society.

Repeated Exposure to Media Violence Is Associated with Diminished Response in an Inhibitory Frontolimbic Network:

Media depictions of violence, although often claimed to induce viewer aggression, have not been shown to affect the cortical networks that regulate behavior. Using functional magnetic resonance imaging (fMRI), we found that repeated exposure to violent media, but not to other equally arousing media, led to both diminished response in right lateral orbitofrontal cortex (right ltOFC) and a decrease in right ltOFC-amygdala interaction. Reduced function in this network has been previously associated with decreased control over a variety of behaviors, including reactive aggression. Indeed, we found reduced right ltOFC responses to be characteristic of those subjects that reported greater tendencies toward reactive aggression. Furthermore, the violence-induced reduction in right ltOFC response coincided with increased throughput to behavior planning regions. These novel findings establish that even short-term exposure to violent media can result in diminished responsiveness of a network associated with behaviors such as reactive aggression.

Time Processing in Huntington’s Disease: A Group-Control Study:

Huntington’s disease (HD) is a genetically inherited neurological disorder. The disease affects circuits in the brain that are involved in timing tasks. Beste and colleagues report that HD patients performed worse than healthy controls in both time estimation and time discrimination tasks. However, individuals who carried the gene variant responsible for HD but who did not have symptoms did worse than controls only in time estimation tasks. These results help elucidate the progression of disease in HD and suggest possible outcomes for evaluating disease status in clinical trials.

Infectious Offspring: How Birds Acquire and Transmit an Avian Polyomavirus in the Wild:

Avian polyomaviruses, a group of DNA-based viruses, are known to cause disease in some bird species. In this study, Potti and colleagues show that such viruses follow an “upwards vertical” route of transmission in a host population of pied flycatchers. The virus seems to spread from the parasitic fly larvae that infect the nests to the nestlings, which, in turn, pass on the virus to their parents through the parents’ disposal of the nestlings’ feces. The results suggest a possible cost associated with parental care; this cost may differ between the sexes as a result of their different roles in breeding tasks.

Oxygen Reperfusion Damage in an Insect:

The effects of oxygen reperfusion damage to organs and tissues following periods of oxygen starvation are well documented in higher organisms like mammals. In this study, Lighton and colleagues induced oxygen reperfusion in Drosophila melanogaster, to determine the resulting functional damage in an invertebrate. The results show the potential of Drosophila as a model organism for further research into reperfusion injury.

Dynamic Perceptual Changes in Audiovisual Simultaneity:

The timing at which sensory input reaches the level of conscious perception is an intriguing question still awaiting an answer. It is often assumed that both visual and auditory percepts have a modality specific processing delay and their difference determines perceptual temporal offset. Here, we show that the perception of audiovisual simultaneity can change flexibly and fluctuates over a short period of time while subjects observe a constant stimulus. We investigated the mechanisms underlying the spontaneous alternations in this audiovisual illusion and found that attention plays a crucial role. When attention was distracted from the stimulus, the perceptual transitions disappeared. When attention was directed to a visual event, the perceived timing of an auditory event was attracted towards that event. This multistable display illustrates how flexible perceived timing can be, and at the same time offers a paradigm to dissociate perceptual from stimulus-driven factors in crossmodal feature binding. Our findings suggest that the perception of crossmodal synchrony depends on perceptual binding of audiovisual stimuli as a common event.

I thought the name sounded familiar when I checked the newest papers published in PLoS Biology today – yup, that’s him, my SciBling and friend Alex Palazzo:
The Signal Sequence Coding Region Promotes Nuclear Export of mRNA by Alexander F. Palazzo, Michael Springer, Yoko Shibata, Chung-Sheng Lee, Anusha P. Dias and Tom A. Rapoport:

In eukaryotic cells, precursors of messenger RNAs (mRNAs) are synthesized and processed in the nucleus. During processing, noncoding introns are spliced out, and a cap and poly-adenosine sequence are added to the beginning and end of the transcript, respectively. The resulting mature mRNA is exported from the nucleus to the cytoplasm by crossing the nuclear pore. Both the introns and the cap help to recruit factors that are necessary for nuclear export of an mRNA. Here we provide evidence for a novel mRNA export pathway that is specific for transcripts coding for secretory proteins. These proteins contain signal sequences that target them for translocation across the endoplasmic reticulum membrane. We made the surprising observation that the signal sequence coding region (SSCR) can serve as a nuclear export signal of an mRNA that lacks an intron or functional cap. Even the export of an intron-containing natural mRNA was enhanced by its SSCR. The SSCR export signal appears to be characterized in vertebrates by a low content of adenines. Our discovery of an SSCR-mediated pathway explains the previously noted amino acid bias in signal sequences, and suggests a link between nuclear export and membrane targeting of mRNAs.

And check out the editorial synposis as well: Secretory Protein mRNA Finds Another Way Out

In Promiscuous Antelopes, The ‘Battle Of The Sexes’ Gets Flipped:

In some promiscuous species, sexual conflict runs in reverse, reveals a new study. Among African topi antelopes, females are the ones who aggressively pursue their mates, while males play hard to get.

(which Kate explained a few days ago – is ScienceDaily that slow?)
Dinosaur Mummy Found With Fossilized Skin And Soft Tissues:

The amazing discovery of one of the finest and rarest dinosaur specimens ever unearthed — a partially intact dino mummy found in the Hell Creek Formation Badlands of North Dakota was made by 16-year-old fossil hunter Tyler Lyson on his uncle’s farm.

Skin Aging Reversed In Mice By Blocking Action Of Single Protein:

Researchers at the Stanford University School of Medicine have reversed the effects of aging on the skin of mice, at least for a short period, by blocking the action of a single critical protein.

Rodent Fossils Provide Data On Climate Six Million Years Ago:

How did the rodents which inhabited the south of the Iberian Peninsula live six million years ago? The researcher of the UGR Raef Minwer-Barakat has attempted to answer this question through his doctoral thesis “Rodents and insectivorous of Upper Turoliense and the Pliocene of the central section of the Guadix basin”, supervised by doctors Elvira Martín and César Viseras, of the Department of Stratigraphy y Palaeontology of the Universidad de Granada. His studied has concluded with the discovering of three new species of rodents and insectivores (Micromys caesaris, Blarinoides aliciae and Archaeodesmana elvirae) and the finding, for the first time in the region, of nine more species.

Choosing Dry Or Wet Food For Cats Makes Little Difference When It Comes To Feline Diabetes:

Although society is accustomed to seeing Garfield-sized cats, obese, middle-aged cats can have a variety of problems including diabetes mellitus, which can be fatal. The causes of diabetes mellitus in cats remain unknown, although there has been a strong debate about whether a dry food diet puts cats at greater risk for diabetes. A new study from a University of Missouri-Columbia veterinarian suggests that weight gain, not the type of diet, is more important when trying to prevent diabetes in cats.

Honey A Better Option For Childhood Cough Than Over The Counter Medications:

A new study by a Penn State College of Medicine research team found that honey may offer parents an effective and safe alternative than over the counter children’s cough medicines.

Fossils Excavated From Bahamian Blue Hole May Give Clues Of Early Life:

Long before tourists arrived in the Bahamas, ancient visitors took up residence in this archipelago off Florida’s coast and left remains offering stark evidence that the arrival of humans can permanently change — and eliminate — life on what had been isolated islands, says a University of Florida researcher.

Malaria Parasite In Patient Blood Finds Distinct Physiological States:

The malaria parasite has been studied for decades, but surprisingly, little is known about how it behaves in humans to cause disease. In a groundbreaking study in Nature, an international research team has for the first time measured which of the parasite’s genes are turned on or off during actual infection in humans, not in cell cultures, unearthing surprising behaviors and opening a window on the most critical aspects of parasite biology.

Coral Reefs Living In Sites With Variable Temperatures Better Able To Survive Warm Water:

Finally, some good news about the prospects of coral reefs in the age of climate change. According to a new study by the Wildlife Conservation Society, corals may actually survive rising ocean temperatures in ‘tough love’ seas with wide-ranging temperatures.

Let’s see what is new in PLoS Pathogens, PLoS Genetics, PLoS Computational Biology and PLoS Neglected Tropical Diseases:
A new installment in the “Ten Simple Rules” series: Ten Simple Rules for Graduate Students

Choosing to go to graduate school is a major life decision. Whether you have already made that decision or are about to, now it is time to consider how best to be a successful graduate student. Here are some thoughts from someone who holds these memories fresh in her mind (JG) and from someone who has had a whole career to reflect back on the decisions made in graduate school, both good and bad (PEB). These thoughts taken together, from former student and mentor, represent experiences spanning some 25 or more years. For ease, these experiences are presented as ten simple rules, in approximate order of priority as defined by a number of graduate students we have consulted here in the US; but we hope the rules are more globally applicable, even though length, method of evaluation, and institutional structure of graduate education varies widely. These rules are intended as a companion to earlier editorials covering other areas of professional development.

Computational Biology in Cuba: An Opportunity to Promote Science in a Developing Country:

Computational biology can be considered a supradisciplinary field of knowledge that merges biology, chemistry, physics, and computer science into a broad-based science that is important to furthering our understanding of the life sciences. Although a relatively new area of research, it is recognized as a crucial field for scientific advancement in developing countries. This Perspective introduces our vision of the role of computational biology in biomedical research and teaching in Cuba. Except where individuals are directly quoted, any opinions expressed herein should be considered those of the authors.

Fortunately, nobody from PLoS will have to go prison for publishing research originating in Cuba.
Measuring the Burden of Neglected Tropical Diseases: The Global Burden of Disease Framework:

Governments and international agencies are faced with setting priorities for health research and investment in health systems and health interventions in a context of increasing health care costs, increasing availability of effective interventions, and numerous and diverse priorities and interest groups. Evidence on the magnitude and trends of diseases and their causes should be a critical input to decision making at the global, national, and local levels. Broad evaluation of the effectiveness of health systems and major health programs and policies also requires assessments of the causes of loss of health that are comparable not only across populations, but also over time.

Lessons from “Lower” Organisms: What Worms, Flies, and Zebrafish Can Teach Us about Human Energy Metabolism:

A pandemic of metabolic diseases (atherosclerosis, diabetes mellitus, and obesity), unleashed by multiple social and economic factors beyond the control of most individuals, threatens to diminish human life span for the first time in the modern era. Given the redundancy and inherent complexity of processes regulating the uptake, transport, catabolism, and synthesis of nutrients, magic bullets to target these diseases will be hard to find. Recent studies using the worm Caenorhabditis elegans, the fly Drosophila melanogaster, and the zebrafish Danio rerio indicate that these “lower” metazoans possess unique attributes that should help in identifying, investigating, and even validating new pharmaceutical targets for these diseases. We summarize findings in these organisms that shed light on highly conserved pathways of energy homeostasis.

Ocean Fertilization ‘Fix’ For Global Warming Discredited By New Research:

Scientists have revealed an important discovery that raises doubts concerning the viability of plans to fertilize the ocean to solve global warming, a projected $100 billion venture.

Separating The Therapeutic Benefits Of Cannabis From Its Mood-altering Side-effects:

Scientists from Queen Mary, University of London, have discovered a new way to separate the therapeutic benefits of cannabis from its mood-altering side-effects.

Human Genome Has Four Times More Imprinted Genes Than Previously Identified:

Scientists at Duke University have created the first map of imprinted genes throughout the human genome, and they say a modern-day Rosetta stone — a form of artificial intelligence called machine learning — was the key to their success. The study revealed four times as many imprinted genes as had been previously identified.

More Than One-quarter Of US Bird Species Imperiled, Report States:

One hundred seventy-eight species in the continental U.S. and 39 in Hawaii have the dubious distinction of landing on the newest and most scientifically sound list of America’s most imperiled birds. WatchList 2007, a joint effort of Audubon and American Bird Conservancy, reflects a comprehensive analysis of population size and trends, distribution, and threats for 700 bird species in the U.S. It reveals those in greatest need of immediate conservation help simply to survive amid a convergence of environmental challenges, including habitat loss, invasive species and global warming.

Endangered Brazilian Ocelot Kitten Born: Birth Significant For Species:

An endangered Brazilian ocelot kitten was born at the Louisville Zoo Sept. 23. This was the first offspring for mom Miguela and second for father Itirapua.

Gene Study Supports Single Main Migration Across Bering Strait:

Did a relatively small number of people from Siberia who trekked across a Bering Strait land bridge some 12,000 years ago give rise to the native peoples of North and South America?

Greg Laden and Jake Young comment.
Dogs Can Classify Complex Photos In Categories Like Humans Do:

Like us, our canine friends are able to form abstract concepts. Friederike Range and colleagues from the University of Vienna in Austria have shown for the first time that dogs can classify complex color photographs and place them into categories in the same way that humans do. And the dogs successfully demonstrate their learning through the use of computer automated touch-screens, eliminating potential human influence.

Using Beetle Biology To Protect Beehives:

A new way to lessen damage from small hive beetles in honey bee colonies has been developed by Agricultural Research Service (ARS) scientists in Gainesville, Fla. Small hive beetles (Aethina tumida) began appearing in U.S. hives during the past 15 to 20 years and now infest bee colonies throughout the East.

Stopping for Deer: Sensing, Movement And Behavior Illuminated:

Driving down a country road at night your car’s headlights illuminate a deer in your path, and the creature doesn’t move. Depending on your speed and other conditions, chances are good you will hit the deer. And if you do, it’s because you are in what is fittingly defined as the “collision mode,” according to a Northwestern University study.

There are 35 brand new papers on PLoS ONE tonight and it is difficult for me to pick the most exciting for the week. So, here is one on the effects of night-shift, one on melanopsin and light perception, one on time perception, one on limb regeneration in the Axolotl, a meta-analysis of the soil ecology literature and, a first for PLoS ONE, an article by a prominent philosopher of science that I expect to be discussed on blogs over the next few days:
Acute Sleep Deprivation and Circadian Misalignment Associated with Transition onto the First Night of Work Impairs Visual Selective Attention:

Overnight operations pose a challenge because our circadian biology promotes sleepiness and dissipates wakefulness at night. Since the circadian effect on cognitive functions magnifies with increasing sleep pressure, cognitive deficits associated with night work are likely to be most acute with extended wakefulness, such as during the transition from a day shift to night shift. To test this hypothesis we measured selective attention (with visual search), vigilance (with Psychomotor Vigilance Task [PVT]) and alertness (with a visual analog scale) in a shift work simulation protocol, which included four day shifts followed by three night shifts. There was a nocturnal decline in cognitive processes, some of which were most pronounced on the first night shift. The nighttime decrease in visual search sensitivity was most pronounced on the first night compared with subsequent nights (p = .04), and this was accompanied by a trend towards selective attention becoming ‘fast and sloppy’. The nighttime increase in attentional lapses on the PVT was significantly greater on the first night compared to subsequent nights (p<.05) indicating an impaired ability to sustain focus. The nighttime decrease in subjective alertness was also greatest on the first night compared with subsequent nights (p<.05). These nocturnal deficits in attention and alertness offer some insight into why occupational errors, accidents, and injuries are pronounced during night work compared to day work. Examination of the nighttime vulnerabilities underlying the deployment of attention can be informative for the design of optimal work schedules and the implementation of effective countermeasures for performance deficits during night work.

Brain Responses to Violet, Blue, and Green Monochromatic Light Exposures in Humans: Prominent Role of Blue Light and the Brainstem:

Melanopsin is a pigment that responds to light and is found in specialised light sensitive cells of the retina. In this paper, Maquet and colleagues investigated the spectral sensitivity of immediate brain responses to light by measuring brain activity in participants exposed to different wavelengths. Their results reveal that short exposures to light induce changes in brain activity and that the melanopsin system provides the most important contribution to these changes.

The Effect of Predictability on Subjective Duration:

Events can sometimes appear longer or shorter in duration than other events of equal length. For example, in a repeated presentation of auditory or visual stimuli, an unexpected object of equivalent duration appears to last longer. Illusions of duration distortion beg an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? In other words, what entailments do duration distortions have with respect to other timing judgments? We here show that when a sound or visual flicker is presented in conjunction with an unexpected visual stimulus, neither the pitch of the sound nor the frequency of the flicker is affected by the apparent duration dilation. This demonstrates that subjective time in general is not slowed; instead, duration judgments can be manipulated with no concurrent impact on other temporal judgments. Like spatial vision, time perception appears to be underpinned by a collaboration of separate neural mechanisms that usually work in concert but are separable. We further show that the duration dilation of an unexpected stimulus is not enhanced by increasing its saliency, suggesting that the effect is more closely related to prediction violation than enhanced attention. Finally, duration distortions induced by violations of progressive number sequences implicate the involvement of high-level predictability, suggesting the involvement of areas higher than primary visual cortex. We suggest that duration distortions can be understood in terms of repetition suppression, in which neural responses to repeated stimuli are diminished.

Transforming Growth Factor: β Signaling Is Essential for Limb Regeneration in Axolotls:

The axolotl limb has been widely studied in developmental biology because of its unusual ability to regenerate following injury. In this study, the authors investigated the role of the transforming growth factor-beta (TGF-β) family members in axolotl limb regeneration. Their results show that the inhibition of TGF-β stopped the redevelopment process, thus suggesting that TGF-β is essential in limb regeneration.

A Tale of Four Stories: Soil Ecology, Theory, Evolution and the Publication System:

Soil ecology has produced a huge corpus of results on relations between soil organisms, ecosystem processes controlled by these organisms and links between belowground and aboveground processes. However, some soil scientists think that soil ecology is short of modelling and evolutionary approaches and has developed too independently from general ecology. We have tested quantitatively these hypotheses through a bibliographic study (about 23000 articles) comparing soil ecology journals, generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. We have shown that soil ecology is not well represented in generalist ecology journals and that soil ecologists poorly use modelling and evolutionary approaches. Moreover, the articles published by a typical soil ecology journal (Soil Biology and Biochemistry) are cited by and cite low percentages of articles published in generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. This confirms our hypotheses and suggests that soil ecology would benefit from an effort towards modelling and evolutionary approaches. This effort should promote the building of a general conceptual framework for soil ecology and bridges between soil ecology and general ecology. We give some historical reasons for the parsimonious use of modelling and evolutionary approaches by soil ecologists. We finally suggest that a publication system that classifies journals according to their Impact Factors and their level of generality is probably inadequate to integrate “particularity” (empirical observations) and “generality” (general theories), which is the goal of all natural sciences. Such a system might also be particularly detrimental to the development of a science such as ecology that is intrinsically multidisciplinary.

Beyond the Gene by Evelyn Fox Keller and David Harel:

This paper is a response to the increasing difficulty biologists find in agreeing upon a definition of the gene, and indeed, the increasing disarray in which that concept finds itself. After briefly reviewing these problems, we propose an alternative to both the concept and the word gene–an alternative that, like the gene, is intended to capture the essence of inheritance, but which is both richer and more expressive. It is also clearer in its separation of what the organism statically is (what it tangibly inherits) and what it dynamically does (its functionality and behavior). Our proposal of a genetic functor, or genitor, is a sweeping extension of the classical genotype/phenotype paradigm, yet it appears to be faithful to the findings of contemporary biology, encompassing many of the recently emerging–and surprisingly complex–links between structure and functionality.

Bear Hunting Altered Genetics More Than Ice Age Isolation:

It was not the isolation of the Ice Age that determined the genetic distribution of bears, as has long been thought. This is shown by an international research team led from Uppsala University in Sweden in the latest issue of Molecular Ecology. One possible interpretation is that the hunting of bears by humans and human land use have been crucial factors.

Mediterranean Sea: Most Dangerous Place On Earth For Sharks And Rays:

The first complete IUCN Red List assessment of the status of all Mediterranean sharks and rays has revealed that 42% of the species are threatened with extinction. Overfishing, including bycatch (non-target species caught incidentally), is the main cause of decline, according to the research.

Nicotine May Enhance Attention And Working Memory In Recovering Alcoholics:

Detoxified alcoholics in the early stages of recovery tend to have impaired cognitive functioning. Many alcoholics also smoke, and nicotine is known to have enhancing effects on attentional processes. New findings indicate that nicotine patches can enhance cognitive function among newly recovering alcoholics with a history of smoking.

Facial Expressions Have Greater Impact On Kids With Bipolar Disorder:

Children with bipolar disorder respond differently to facial expressions than children without psychiatric disorders, according to a new study led by a Bradley Hospital researcher. These findings provide additional insight into the neurobiology of pediatric bipolar disorder.

Why Age Doesn’t Matter For Motherhood:

The assumption that those born to mothers outside the optimum age for reproduction are disadvantaged has been challenged by scientists at the University of Exeter. Their research found that mothers adjust their pre and post-natal care to compensate for any health problems their babies might face as a result of them being below or above the best age to give birth.

Ripening Secrets Of The Vine Revealed:

Whether you prefer a Cabernet Sauvignon or a Pinot Noir grape variety, two new research articles offer a host of new genetic information on fruit ripening for this economically important fruit crop.

Environmental Researchers Propose Radical ‘Human-centric’ Map Of The World:

Ecologists pay too much attention to increasingly rare “pristine” ecosystems while ignoring the overwhelming influence of humans on the environment, say researchers from McGill University and the University of Maryland, Baltimore County (UMBC).

Are Current Projections Of Climate Change Impacts On Biodiversity Misleading?:

Are patterns of current climate sufficient to explain and predict the diversity of life? This is the urgent question arising from the study “Quaternary climate changes explain diversity among reptiles and amphibians,” published in the journal Ecography. The new theory proposes that historical climate patterns are of strong importance to diversity prediction.

Yup, it’s Monday evening:
Light Activates Output from Evening Neurons and Inhibits Output from Morning Neurons in the Drosophila Circadian Clock:

Living organisms have evolved circadian clocks that anticipate daily changes in their environment. Their clockwork is fully endogenous, but can be reset by external cues. (Light is the most efficient cue.) The circadian neuronal network of the fruit fly (Drosophila) brain perceives light through the visual system and a dedicated photoreceptor molecule, cryptochrome. Flies exhibit a bimodal locomotor activity pattern that peaks at dawn and dusk in light-dark conditions. These morning and evening activity bouts are controlled by two distinct neuronal clocks in the fly brain. By using flies with a deficient cryptochrome pathway, we have uncovered an unexpected role for light in the circadian system. In addition to synchronizing the two oscillators to solar time, light also controls their behavioral output. The morning oscillator can periodically rouse the fly when in constant darkness, but not in constant light, whereas the evening oscillator can do the same in constant light, but not in constant darkness. This suggests the existence of a light-dependent switch between oscillators that appears to require the visual system. Such a mechanism likely contributes to better separate the active periods of the fly at dawn and dusk, and may help the animal to adapt to seasonal changes in day length.

How Can We Draw the Line between Clinical Care and Medical Research:

A Policy Forum published in this month’s PLoS Medicine highlights an issue that the PLoS Medicine editors have often debated: when research takes place within the context of clinical care, how can we distinguish which activities constitute care, and which research? The World Medical Association Code of Medical Ethics declares that a physician must always “act in the patient’s best interest when providing medical care” [1]. Yet increasingly physicians also undertake research, which involves possibly unknown risks and benefits. These risks, and the uncertainty of benefit, might therefore conflict with a patient’s best interests.

Bioclocks Work By Controlling Chromosome Coiling:

There is a new twist on the question of how biological clocks work. In recent years, scientists have discovered that biological clocks help organize a dizzying array of biochemical processes in the body. Despite a number of hypotheses, exactly how the microscopic pacemakers in every cell in the body exert such a widespread influence has remained a mystery.
Now, a new study provides direct evidence that biological clocks can influence the activity of a large number of different genes in an ingenious fashion, simply by causing chromosomes to coil more tightly during the day and to relax at night.

Is The Beauty Of A Sculpture In The Brain Of The Beholder?:

Is there an objective biological basis for the experience of beauty in art? Or is aesthetic experience entirely subjective? This question has been addressed in a new article by Cinzia Di Dio, Emiliano Macaluso and Giacomo Rizzolatti. The researchers used fMRI scans to study the neural activity in subjects with no knowledge of art criticism, who were shown images of Classical and Renaissance sculptures.

Carnivorous Plants Use Pitchers Of ‘Slimy Saliva’ To Catch Their Prey:

Carnivorous plants supplement the meager diet available from the nutrient-poor soils in which they grow by trapping and digesting insects and other small arthropods. Pitcher plants of the genus Nepenthes were thought to capture their prey with a simple passive trap but in a paper in PLoS One, Laurence Gaume and Yoel Forterre, a biologist and a physicist from the CNRS, working respectively in the University of Montpellier and the University of Marseille, France show that they employ slimy secretions to doom their victims.

Horses Disperse Alien Plants Along Recreational Trails:

Plant invasions are rapidly becoming a threat to wildlands. One of the ways these aliens are dispersed is through large mammals that forage and excrete seeds in new locations. A new study has found horses to be a source of dispersal along recreational trails in Colorado.

Polar Bears Threatened By Hunting Policy Favoring The Killing Of Male Bears:

Policies that encourage hunters to go after male polar bears in order to conserve females, could make it harder for the animals to find mates. University of Alberta researchers determined there is a critical threshold in the male-to-female ratio. Below it, their model predicts a sudden and rapid collapse in fertilization rates.

Giant Fossil Sea Scorpion Bigger Than Man:

The discovery of a giant fossilised claw from an ancient sea scorpion indicates that when alive it would have been about two and a half meters long, much taller than the average man.

Unraveling the Silky Spider Web:

Web-making spiders employ a host of silk glands to synthesize a variety of silk filaments with different mechanical properties. Although it is widely believed that the aciniform glands are one such silk factory, there has been no hard evidence linking aciniform-derived proteins and silk –until now.

There are 34 articles published in PLoS ONE this week. As always, look around, read, rate, comment, annotate…. Here are my picks for the week (no need to repeat the dinosaur paper here, of course):
A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants:

Carnivorous pitcher plants supplement their nutrient intake by trapping and digesting insects in what were thought to be passive pitfall traps. But in this study, the authors show that the pitchers of plants Nepenthes rafflesiana in fact employ highly specialized secretions to doom their victims. They show that this fluid, even when diluted, has the perfect viscoelastic properties to prevent the escape of any small creatures that come into contact with it.

The Golden Beauty: Brain Response to Classical and Renaissance Sculptures:

Speculation and debate often surround the question of whether the experience of beauty in art is based upon objective biological factors or individual subjective perception. In this study, a group of researchers attempted to answer this question by measuring brain activity in people who were exposed to original and modified images of masterpieces of Classical and Renaissance sculpture. The results suggest that in naïve art observers, a sense of beauty is determined by both objective beauty and emotional experiences.

The Effect of Real-World Personal Familiarity on the Speed of Face Information Processing:

In this study, Balas and colleagues investigated whether people’s ability to process basic information about other individuals’ faces (for example, making a decision on the individual’s gender, identity, or orientation of the image) is affected by whether they know that person. The results showed, surprisingly, that real-world familiarity with an individual helps a person to process visual cues relating to that individual faster, even if identity is not required for performing that task. These findings highlight the importance of experience and familiarity in determining visual recognition processes.

Reappraisal of Vipera aspis Venom Neurotoxicity:

The variation of venom composition with geography is an important aspect of intraspecific variability in the Vipera genus, although causes of this variability remain unclear. The diversity of snake venom is important both for our understanding of venomous snake evolution and for the preparation of relevant antivenoms to treat envenomations. A geographic intraspecific variation in snake venom composition was recently reported for Vipera aspis aspis venom in France. Since 1992, cases of human envenomation after Vipera aspis aspis bites in south-east France involving unexpected neurological signs were regularly reported. The presence of genes encoding PLA2 neurotoxins in the Vaa snake genome led us to investigate any neurological symptom associated with snake bites in other regions of France and in neighboring countries. In parallel, we used several approaches to characterize the venom PLA2 composition of the snakes captured in the same areas. We conducted an epidemiological survey of snake bites in various regions of France. In parallel, we carried out the analysis of the genes and the transcripts encoding venom PLA2s. We used SELDI technology to study the diversity of PLA2 in various venom samples. Neurological signs (mainly cranial nerve disturbances) were reported after snake bites in three regions of France: Languedoc-Roussillon, Midi-Pyrénées and Provence-Alpes-Côte d’Azur. Genomes of Vipera aspis snakes from south-east France were shown to contain ammodytoxin isoforms never described in the genome of Vipera aspis from other French regions. Surprisingly, transcripts encoding venom neurotoxic PLA2s were found in snakes of Massif Central region. Accordingly, SELDI analysis of PLA2 venom composition confirmed the existence of population of neurotoxic Vipera aspis snakes in the west part of the Massif Central mountains. The association of epidemiological studies to genetic, biochemical and immunochemical analyses of snake venoms allowed a good evaluation of the potential neurotoxicity of snake bites. A correlation was found between the expression of neurological symptoms in humans and the intensity of the cross-reaction of venoms with anti-ammodytoxin antibodies, which is correlated with the level of neurotoxin (vaspin and/or ammodytoxin) expression in the venom. The origin of the two recently identified neurotoxic snake populations is discussed according to venom PLA2 genome and transcriptome data.

Season of Birth and Dopamine Receptor Gene Associations with Impulsivity, Sensation Seeking and Reproductive Behaviors:

Season of birth (SOB) has been associated with many physiological and psychological traits including novelty seeking and sensation seeking. Similar traits have been associated with genetic polymorphisms in the dopamine system. SOB and dopamine receptor genetic polymorphisms may independently and interactively influence similar behaviors through their common effects on the dopaminergic system. Based on a sample of 195 subjects, we examined whether SOB was associated with impulsivity, sensation seeking and reproductive behaviors. Additionally we examined potential interactions of dopamine receptor genes with SOB for the same set of traits. Phenotypes were evaluated using the Sociosexual Orientation Inventory, the Barratt Impulsivity Scale, the Eysenck Impulsivity Questionnaire, the Sensation Seeking Scale, and the Delay Discounting Task. Subjects were also asked about their age at first sex as well as their desired age at the birth of their first child. The dopamine gene polymorphisms examined were Dopamine Receptor D2 (DRD2) TaqI A and D4 (DRD4) 48 bp VNTR. Primary analyses included factorial gender×SOB ANOVAs or binary logistic regression models for each dependent trait. Secondary analysis extended the factorial models by also including DRD2 and DRD4 genotypes as independent variables. Winter-born males were more sensation seeking than non-winter born males. In factorial models including both genotype and season of birth as variables, two previously unobserved effects were discovered: (1) a SOB×DRD4 interaction effect on venturesomeness and (2) a DRD2×DRD4 interaction effect on sensation seeking. These results are consistent with past findings that SOB is related to sensation seeking. Additionally, these results provide tentative support for the hypothesis that SOB modifies the behavioral expression of dopaminergic genetic polymorphism. These findings suggest that SOB should be included in future studies of risky behaviors and behavioral genetic studies of the dopamine system.

‘Noah’s Flood’ Kick-started European Farming?:

The flood believed to be behind the Noah’s Ark myth kick-started European agriculture, according to new research by the Universities of Exeter, UK and Wollongong, Australia. New research assesses the impact of the collapse of the North American (Laurentide) Ice Sheet, 8000 years ago. The results indicate a catastrophic rise in global sea level led to the flooding of the Black Sea and drove dramatic social change across Europe.

Earliest Chocolate Drink Of The New World:

The earliest known use of cacao–the source of our modern day chocolate–has been pushed back more than 500 years, to somewhere between 1400 and 1100 B.C.E., thanks to new chemical analyses of residues extracted from pottery excavated at an archaeological site at Puerto Escondido in Honduras. The new evidence also indicates that, long before the flavor of the cacao seed (or bean) became popular, it was the sweet pulp of the chocolate fruit, used in making a fermented (5% alcohol) beverage, which first drew attention to the plant in the Americas.

Octopus And Kin Inspire New Camouflage Strategies For Military Applications:

Researchers are studying the remarkable shape- and color-changing abilities of the octopus and its close relatives in an effort to understand one of nature’s most remarkable feats of camouflage and self-preservation.

New Evidence For Female Control In Reproduction:

Adding another layer of competition to the mating game, scientists are reporting possible biochemical proof that the reproductive system of female mammals can “sense” the presence of sperm and react to it by changing the uterine environment. This may be the molecular mechanism behind post-copulatory sexual selection, in which females that have mated with several partners play a role in determining which sperm fertilizes their egg.

Earlier Bites By Uninfected Mosquitoes Boost West Nile Deaths In Lab Mice:

There’s one more reason to try to avoid being bitten by mosquitoes, scientists have discovered: bites from mosquitoes that aren’t infected by the West Nile virus may make the disease worse in people who acquire it later from West Nile-infected mosquitoes.

Sunbathing Tree Frogs’ Future Under A Cloud:

Animal conservationists in Manchester are turning to physics to investigate whether global warming is responsible for killing sun-loving South American tree frogs.

Like Father, Like Son: Attractiveness Is Hereditary:

Sexy dads produce sexy sons, in the insect world at least. While scientists already knew that specific attractive traits, from cricket choruses to peacocks’ tails, are passed on to their offspring, the heritability of attractiveness as a whole is more contentious. Now, new research by the University of Exeter shows that attractiveness is hereditary.

Evolution Is Deterministic, Not Random, Biologists Conclude From Multi-species Study:

A multi-national team of biologists has concluded that developmental evolution is deterministic and orderly, rather than random, based on a study of different species of roundworms.

Greg Laden explains.
Telecommuting Has Mostly Positive Consequences For Employees And Employers:

Telecommuting is a win-win for employees and employers, resulting in higher morale and job satisfaction and lower employee stress and turnover. These were among the conclusions of psychologists who examined 20 years of research on flexible work arrangements.

Yes, I know. It’s true.
Gene In Male Fish Lures Females Into Sex:

A gene has been found in male cichlid fish that evolved to lure female fish so that male cichlids can deposit sperm in the females mouths. A study in the online open access journal BMC Biology reveals that the gene is associated with egg-like markings on the fins of cichlid fishes and uncovers the evolutionary history of these markings, which are central to the success of the fishes’ exotic oral mating behaviour.

Evolutionary Biology Research On Plant Shows Significance Of Maternal Effects:

When habitat changes, animals migrate. But how do immobile organisms like plants cope when faced with alterations to their environment? This is an increasingly important question in light of new environmental conditions brought on by global climate change.

Monday night is the time when new articles on PLoS Medicine and PLoS Biology get published. My picks for this week:
Who Needs Cause-of-Death Data:

More than half of the world’s deaths pass by undocumented as to cause. Whilst the appropriate focus of health services may well be the care of the living, consistent and reliable cause-of-death data also constitute a crucial and major resource for health planning and prioritisation, and their lack in many settings is a major concern.

Complex Regulation of cyp26a1 Creates a Robust Retinoic Acid Gradient in the Zebrafish Embryo:

The formation of gradients of morphogens, signaling molecules that determine cell fates in a concentration-dependent manner, is a fundamental process in developmental biology. Several morphogens pattern the anterior-posterior (head to tail) axis of the vertebrate nervous system, including the vitamin A derivative, retinoic acid (RA) and fibroblast growth factors (Fgfs). However, it remains unclear how the activities of such morphogen gradients are coordinated. We have addressed this question by combining genetic experiments in zebrafish and computational analyses. We show that RA acts as a graded signal over long distances and that its gradient is shaped, to a large extent, by local control of RA degradation. In particular, RA promotes and Fgf suppresses RA degradation, thereby linking the shapes of RA and Fgf gradients. Computational models suggest that this linkage helps make RA-mediated patterning robust to changes in the rate at which RA is synthesized (which may vary with levels of dietary vitamin A) as well as in the size and shape of the embryo during development. Analogous regulatory loops may be used for similar purposes in other tissues in which RA and Fgfs interact, as well as in other morphogen systems.

Hormone Of Darkness: Melatonin Could Hurt Memory Formation At Night:

What do you do when a naturally occurring hormone in your body turns against you? What do you do when that same hormone – melatonin – is a popular supplement you take to help you sleep? A University of Houston professor and his team of researchers may have some answers.

Self-organized Traffic Light Control System Could Improve Traffic Flow 95 Percent:

Traffic flows account for as much as one-third of global energy consumption. But unconventional changes in managing traffic flow could significantly reduce such waste and lower harmful CO2 emissions, says Dirk Helbing.

Genital Arousal Disorder Adversely Impacts Women’s Lives:

New research shows that women suffering from Persistent Genital Arousal Disorder (PGAD), a condition marked by unprovoked, intrusive and persistent sensations of genital arousal that are unrelieved by one or several orgasms, are likely to experience a variety of associated psychological conditions. Women who have this rare and often distressing condition often experience related depression, anxiety, panic attacks and frequently show a past history of sexual victimization.

Using Neural Signals To Predict Sensory Decisions:

The rodent whisker sensory system is particularly intriguing because it is “active”: the animal generates sensory signals by palpating objects through self-controlled whisker motion (just as we move our fingertips along surfaces to measure their tactile features).

Delay In Autumn Color Caused By Increased Carbon Dioxide Not Global Warming:

The delay in autumnal leaf coloration and leaf fall in trees is caused by rising levels of carbon dioxide (CO2) in the atmosphere and not by increased global temperatures, suggests a new study by researchers at the University of Southampton.

Zeroing In On Cellular Machinery That Enables Neurons To Fire:

If you ever had a set of Micronauts — toy robots with removable body parts — you probably had fun swapping their heads, imagining how it would affect their behavior. Scientists supported by the National Institutes of Health have been performing similar experiments on ion channels — pores in our nerve cells — to sort out the channels’ key functional parts.

Mud, Mud, Glorious Mud?:

Mother bats know exactly what’s good for them and their young: During pregnancy and lactation female bats are in great need of minerals. Dr. Christian Voigt from the Leibniz Institute for Zoo and Wildlife Research and colleagues found out how fruit-eating bats in the Ecuadorian rainforest cover their mineral requirements.

Trumpeter Swans Re-established In Ontario, Canada:

Originally native to Ontario, the trumpeter swan disappeared from Eastern Canada early in the 20th century. Restoration efforts were initiated in the early 1980s to reintroduce the trumpeter swan to its former range. Through conservation efforts the Ontario population has reached 1000, with at least 131 breeding pairs, and the future looks bright.

Your Homework: come up with a set of experiments that can be published in a single paper that can reasonably cite all the above studies.

How Poisonous Mushrooms Cook Up Toxins:

Alpha-amanitin is the poison of the death cap mushroom, Amanita phalloides. The Michigan State University plant biology research associate was looking for a big gene that makes a big enzyme that produces alpha-amanitin, since that’s how other fungi produce similar compounds. But after years of defeat, she and her team called in the big guns — new technology that sequences DNA about as fast as a death cap mushroom can kill. The results: The discovery of remarkably small genes that produce the toxin — a unique pathway previously unknown in fungi.

Brain Matures A Few Years Late In ADHD, But Follows Normal Pattern:

In youth with attention deficit hyperactivity disorder (ADHD), the brain matures in a normal pattern but is delayed three years in some regions, on average, compared to youth without the disorder, an imaging study by researchers at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has revealed. The delay in ADHD was most prominent in regions at the front of the brain’s outer mantle (cortex), important for the ability to control thinking, attention and planning. Otherwise, both groups showed a similar back-to-front wave of brain maturation with different areas peaking in thickness at different times.

Tool-wielding Chimps Provide A Glimpse Of Early Human Behavior:

Chimpanzees inhabiting a harsh savanna environment and using bark and stick tools to exploit an underground food resource are giving scientists new insights to the behaviors of the earliest hominids who, millions of years ago, left the African forests to range the same kinds of environments and possibly utilize the same foods.

Tiny Fish Can Yield Big Clues To Delaware River Health:

Where have all the bridle shiner gone? That’s the mystery The Academy of Natural Sciences’ fish scientists are trying to answer, and the outcome will shed light on the environmental health of the Upper Delaware River.

Changing Environment Organizes Genetic Structure:

What is the fundamental creative force behind life on Earth? It’s a question that has vexed mankind for millennia, and thanks to theory and almost a year’s worth of number-crunching on a supercomputer, Rice University physicist and bioengineer Michael Deem thinks he has the answer: A changing environment may organize the structure of genetic information itself.

ECGC In Green Tea Is Powerful Medicine Against Severe Sepsis, Lab Study Suggests:

A major component of green tea could prove the perfect elixir for severe sepsis, an abnormal immune system response to a bacterial infection. In a new laboratory study, Haichao Wang, PhD, of The Feinstein Institute for Medical Research, and his colleagues have been studying the therapeutic powers of dozens of Chinese herbal compounds in reversing a fatal immune response that kills 225,000 Americans every year. They found that an ingredient in green tea rescued mice from lethal sepsis — and the findings could pave the way to clinical trials in patients.

How Global Is The Global Biodiversity Information Facility?:

Biologists and computer scientists have appealed for more information on the world’s biodiversity to be stored digitally so it may better be used to understand the impact of climate change on the Earth’s flora and fauna.

‘Time-sharing’ Tropical Birds Key To Evolutionary Mystery:

Whereas most birds are sole proprietors of their nests, some tropical species “time share” together – a discovery that helps clear up a 150-year-old evolutionary mystery, says Biology professor Vicki Friesen.

There are 27 brand-new articles, just uploaded on PLoS ONE. Here are a couple of titles that drew my immediate attention:
Maternal Enrichment during Pregnancy Accelerates Retinal Development of the Fetus:

Although much is known about the harmful effects parental stress has on offspring, little is understood about how enriching a mother’s environment affects fetal development. In this paper, the authors experiment on developing rat embryos and find that an enriched environment speeds up the development of the nervous system. The results suggest that development of the visual system is sensitive to environmental stimulation during prenatal life.

Prior Exposure to Uninfected Mosquitoes Enhances Mortality in Naturally-Transmitted West Nile Virus Infection:

West Nile Virus has the potential to cause serious disease in humans; the virus is spread by infected mosquitoes and typically infection either results in no symptoms or in mild feverish symptoms. In this study, Higgs and colleagues found that mice that had already been exposed to the saliva from uninfected mosquitoes were subsequently more likely to die upon being infected with West Nile Virus. These findings suggest that prior exposure to mosquito saliva could potentially result in a worse outcome from West Nile Virus infection.

Gene Expression in Human Hippocampus from Cocaine Abusers Identifies Genes which Regulate Extracellular Matrix Remodeling:

People who have abused drugs in the past find it hard to avoid relapse because they remember the euphoria linked to previous drug use. In order to see if past drug abuse is associated with molecular changes in the brain, the researchers here carried out microarray analysis of samples of the hippocampus from individuals addicted to cocaine, and from control individuals. The microarray data identifies a number of genes which are up- or down-regulated in response to cocaine exposure.

Incidence and Tracking of Escherichia coli O157:H7 in a Major Produce Production Region in California:

Fresh vegetables have become associated with outbreaks caused by Escherichia coli O157:H7 (EcO157). Between 1995-2006, 22 produce outbreaks were documented in the United States, with nearly half traced to lettuce or spinach grown in California. Outbreaks between 2002 and 2006 induced investigations of possible sources of pre-harvest contamination on implicated farms in the Salinas and San Juan valleys of California, and a survey of the Salinas watershed. EcO157 was isolated at least once from 15 of 22 different watershed sites over a 19 month period. The incidence of EcO157 increased significantly when heavy rain caused an increased flow rate in the rivers. Approximately 1000 EcO157 isolates obtained from cultures of>100 individual samples were typed using Multi-Locus Variable-number-tandem-repeat Analysis (MLVA) to assist in identifying potential fate and transport of EcO157 in this region. A subset of these environmental isolates were typed by Pulse Field Gel Electrophoresis (PFGE) in order to make comparisons with human clinical isolates associated with outbreak and sporadic illness. Recurrence of identical and closely related EcO157 strains from specific locations in the Salinas and San Juan valleys suggests that transport of the pathogen is usually restricted. In a preliminary study, EcO157 was detected in water at multiple locations in a low-flow creek only within 135 meters of a point source. However, possible transport up to 32 km was detected during periods of higher water flow associated with flooding. During the 2006 baby spinach outbreak investigation, transport was also detected where water was unlikely to be involved. These results indicate that contamination of the environment is a dynamic process involving multiple sources and methods of transport. Intensive studies of the sources, incidence, fate and transport of EcO157 near produce production are required to determine the mechanisms of pre-harvest contamination and potential risks for human illness.

Different Neurophysiological Mechanisms Underlying Word and Rule Extraction from Speech:

The initial process of identifying words from spoken language and the detection of more subtle regularities underlying their structure are mandatory processes for language acquisition. Little is known about the cognitive mechanisms that allow us to extract these two types of information and their specific time-course of acquisition following initial contact with a new language. We report time-related electrophysiological changes that occurred while participants learned an artificial language. These changes strongly correlated with the discovery of the structural rules embedded in the words. These changes were clearly different from those related to word learning and occurred during the first minutes of exposition. There is a functional distinction in the nature of the electrophysiological signals during acquisition: an increase in negativity (N400) in the central electrodes is related to word-learning and development of a frontal positivity (P2) is related to rule-learning. In addition, the results of an online implicit and a post-learning test indicate that, once the rules of the language have been acquired, new words following the rule are processed as words of the language. By contrast, new words violating the rule induce syntax-related electrophysiological responses when inserted online in the stream (an early frontal negativity followed by a late posterior positivity) and clear lexical effects when presented in isolation (N400 modulation). The present study provides direct evidence suggesting that the mechanisms to extract words and structural dependencies from continuous speech are functionally segregated. When these mechanisms are engaged, the electrophysiological marker associated with rule-learning appears very quickly, during the earliest phases of exposition to a new language.

As always, look around, read, rate, comment, annotate and send trackbacks…

As always on Monday nights, there are new articles published in PLoS Biology and PLoS Medicine. My picks:
Professional Uncertainty and Disempowerment Responding to Ethnic Diversity in Health Care: A Qualitative Study

In a qualitative study published this week in PLoS Medicine, Joe Kai and colleagues have identified opportunities to empower health professionals to respond more effectively to challenges in their work with patients from diverse ethnic communities. A related perspective showcases the challenges that physicians face in providing culturally appropriate care.

Omnidirectional Sensory and Motor Volumes in Electric Fish:

Most animals, including humans, have sensory and motor capabilities that are biased in the forward direction. The black ghost knifefish, a nocturnal, weakly electric fish from the Amazon, is an interesting exception to this general rule. We demonstrate that these fish have sensing and motor capabilities that are omnidirectional. By combining video analysis of prey capture trajectories with computational modeling of the fish’s electrosensory capabilities, we were able to quantify and compare the 3-D volumes for sensation and movement. We found that the volume in which prey are detected is similar in size to the volume needed by the fish to stop. We suggest that this coupling may arise from constraints that the animal faces when using self-generated energy to probe its environment. This is similar to the way in which the angular coverage and range of an automobile’s headlights are designed to match certain motion characteristics of the vehicle, such as its typical cruising speed, turning angle, and stopping distance. We suggest that the degree of overlap between sensory and movement volumes can provide insight into the types of control strategies that are best suited for guiding behavior.

Also read the related synopsis. Interestingly, electroreception is the only sensory modality studied so far which does not exhibit centrifugal control, i.e., there is no “tuning” by the central nervous system – it is always tuned the same. In other senses (including some weird ones, e.g., magnetoreception), the brain modulates the sensitivity of the sensory organ. In all those cases, one of those modulations is by the circadian clock. Thus, all the senses except electroreception are more or less sensitive depending on the time of day. I wonder about the other active senses, i.e., senses in which animal emits something into the environment and then senses how the environment responds to it (e.g., sonar in dolphins, ultrasonic emitions of bats, etc.) as I am not sure those were studied.

How Well Do Dogs See At Night?:

A lot better than we do, says Paul Miller, clinical professor of comparative ophthalmology at University of Wisconsin-Madison.

Why Quitting Smoking Is So Difficult:

New findings clarify the brain mechanisms that explain many aspects of dependency on nicotine, the addictive substance in tobacco. Among them: Individual differences in brain chemistry can have a profound effect on a person’s susceptibility to addiction, and smoking may predispose adolescents to mental disorders in adolescence and adulthood. In addition, researchers have identified a potential neural network that regulates the body’s craving response and have demonstrated how smoking may affect decision-making.

For Migrating Sparrows, Kids Have A Compass, But Adults Have The Map:

Even bird brains can get to know an entire continent — but it takes them a year of migration to do so, suggests a Princeton research team.

One In Five Young Britons Has Sex With Someone New While Abroad:

Around one in five young Britons has sex with a new partner while overseas, finds research published ahead of print in the journal Sexually Transmitted Infections.

How The Brain Sends Eyeballs Bouncing:

All vision, including reading this sentence, depends on a constant series of infinitesimal jumps by the eyeball that centers the retina on target objects–words or phrases in the case of reading. Such jumps, or saccades, are critical to vision because only the small central region of the retina, called the fovea, produces the clear image necessary for perception. Such saccades take place several times a second and are generated within a brain region known as the frontal eye field (FEF).

Why Teens Are Such Impulsive Risk-takers:

Teenagers and adults often don’t see eye to eye, and new brain research is now shedding light on some of the reasons why. Although adolescence is often characterized by increased independence and a desire for knowledge and exploration, it also is a time when brain changes can result in high-risk behaviors, addiction vulnerability, and mental illness, as different parts of the brain mature at different rates.

When To Have A Child? A New Approach To The Decision:

Women seeking to balance career, social life and family life in making the decision on when to have a child may benefit from applying formal decision-making science to this complex emotional choice.

Bug-Zapper: A Dose Of Radiation May Help Knock Out Malaria:

How are physicists helping an effort to eradicate malaria, the mosquito-borne disease that kills more than one million people every year” Researchers at the National Institute of Standards and Technology (NIST) used their expertise in radiation science to help a young company create weakened, harmless versions of the malaria-causing parasite. These parasites, in turn, are being used to create a new type of vaccine that shows promise of being more effective than current malaria vaccines.

Why Dinosaurs Had ‘Fowl’ Breath:

Scientists have discovered how dinosaurs used to breathe in what provides clues to how they evolved and how they might have lived.

Sexist Humor No Laughing Matter, Psychologist Says:

A research project led by a Western Carolina University psychology professor indicates that jokes about blondes and women drivers are not just harmless fun and games; instead, exposure to sexist humor can lead to toleration of hostile feelings and discrimination against women.

Recreational Cocaine Use May Impair Inhibitory Control:

The recreational use of cocaine has rapidly increased in many European countries over the past few years. One cause of this is the fall in the price of the drug on the street from 100 Euros for one gram (about 5 lines) in 2000 to 50 Euros in the Netherlands today. One line of cocaine is, thus, now as cheap as a tablet of ecstasy. This means cocaine is no longer considered an “elite” drug but is affordable for all, especially for recreational use. It is therefore likely that the recreational use of cocaine will become a public health issue in the next few years, which is already the case for the recreational use of ecstasy.

To Fight Disease, Animals — Like Plants — Can Tolerate Parasites:

Animals, like plants, can build tolerance to infections at a genetic level, and these findings could provide a better understanding of the epidemiology and evolution of infectious disease, according to evolutionary biologists.

Lack Of Critical Lubricant Causes Wear In Animal Joints:

Mice that don’t produce lubricin, a thin film of protein found in the cartilage of joints, showed early wear and higher friction in their joints, a new study led by Brown University researchers shows.

Evolution: When Are Genes ‘Adventurous’ And When Are They Conservative?:

Taking a chance on an experiment – this is one of the impulses that drive evolution. Living cells are, from this angle, great subjects for experimentation: Changes in one molecule can have all sorts of interesting consequences for many other molecules in the cell. Such experiments on genes and proteins have led the cell, and indeed all life, on a long and fascinating evolutionary journey.

As always on Tuesdays late in the evening, there is a bunch of new papers published in PLoS ONE and here are my personal favourites of the week:
Oxytocin Increases Generosity in Humans:

Human beings routinely help strangers at costs to themselves. Sometimes the help offered is generous–offering more than the other expects. The proximate mechanisms supporting generosity are not well-understood, but several lines of research suggest a role for empathy. In this study, participants were infused with 40 IU oxytocin (OT) or placebo and engaged in a blinded, one-shot decision on how to split a sum of money with a stranger that could be rejected. Those on OT were 80% more generous than those given a placebo. OT had no effect on a unilateral monetary transfer task dissociating generosity from altruism. OT and altruism together predicted almost half the interpersonal variation in generosity. Notably, OT had twofold larger impact on generosity compared to altruism. This indicates that generosity is associated with both altruism as well as an emotional identification with another person.

Impaired Inhibitory Control in Recreational Cocaine Users:

Chronic use of cocaine is associated with impairment in response inhibition but it is an open question whether and to which degree findings from chronic users generalize to the upcoming type of recreational users. This study compared the ability to inhibit and execute behavioral responses in adult recreational users and in a cocaine-free-matched sample controlled for age, race, gender distribution, level of intelligence, and alcohol consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop-signals than non users. Interestingly, the magnitude of the inhibitory deficit was positively correlated with the individuals lifetime cocaine exposure suggesting that the magnitude of the impairment is proportional to the degree of cocaine consumed.

Processing of Abstract Rule Violations in Audition:

The ability to encode rules and to detect rule-violating events outside the focus of attention is vital for adaptive behavior. Our brain recordings reveal that violations of abstract auditory rules are processed even when the sounds are unattended. When subjects performed a task related to the sounds but not to the rule, rule violations impaired task performance and activated a network involving supratemporal, parietal and frontal areas although none of the subjects acquired explicit knowledge of the rule or became aware of rule violations. When subjects tried to behaviorally detect rule violations, the brain’s automatic violation detection facilitated intentional detection. This shows the brain’s capacity for abstraction – an important cognitive function necessary to model the world. Our study provides the first evidence for the task-independence (i.e. automaticity) of this ability to encode abstract rules and for its immediate consequences for subsequent mental processes.

DNA Barcoding in the Cycadales: Testing the Potential of Proposed Barcoding Markers for Species Identification of Cycads:

The use of DNA barcoding to describe species that lack diagnostic features is becoming increasingly important for animal and plant conservation. In this paper, Specht and colleagues tested various genomic regions from a specific group of plants, the Cycadales, to see how effective these might be in providing unique species identifiers. The results enabled the researchers to suggest a workflow for producing and testing DNA barcoding data, which is an essential requirement to the establishment of a universal DNA barcode for plants.

A Major Ingredient of Green Tea Rescues Mice from Lethal Sepsis Partly by Inhibiting HMGB1:

The pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., TNF, IL-1, and IFN-γ) and late (e.g., HMGB1) pro-inflammatory cytokines. Our recent discovery of HMGB1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. We previously reported that green tea brewed from the leaves of the plant Camellia sinensis is effective in inhibiting endotoxin-induced HMGB1 release. Here we demonstrate that its major component, (-)-epigallocatechin-3-gallate (EGCG), but not catechin or ethyl gallate, dose-dependently abrogated HMGB1 release in macrophage/monocyte cultures, even when given 2-6 hours post LPS stimulation. Intraperitoneal administration of EGCG protected mice against lethal endotoxemia, and rescued mice from lethal sepsis even when the first dose was given 24 hours after cecal ligation and puncture. The therapeutic effects were partly attributable to: 1) attenuation of systemic accumulation of proinflammatory mediator (e.g., HMGB1) and surrogate marker (e.g., IL-6 and KC) of lethal sepsis; and 2) suppression of HMGB1-mediated inflammatory responses by preventing clustering of exogenous HMGB1 on macrophage cell surface. Taken together, these data suggest a novel mechanism by which the major green tea component, EGCG, protects against lethal endotoxemia and sepsis.

The Biomechanics of Amnion Rupture: An X-Ray Diffraction Study:

Pre-term birth is the leading cause of perinatal and neonatal mortality, 40% of which are attributed to the pre-term premature rupture of amnion. Rupture of amnion is thought to be associated with a corresponding decrease in the extracellular collagen content and/or increase in collagenase activity. However, there is very little information concerning the detailed organisation of fibrillar collagen in amnion and how this might influence rupture. Here we identify a loss of lattice like arrangement in collagen organisation from areas near to the rupture site, and present a 9% increase in fibril spacing and a 50% decrease in fibrillar organisation using quantitative measurements gained by transmission electron microscopy and the novel application of synchrotron X-ray diffraction. These data provide an accurate insight into the biomechanical process of amnion rupture and highlight X-ray diffraction as a new and powerful tool in our understanding of this process.

Unexpected High Losses of Anopheles gambiae Larvae Due to Rainfall:

Immature stages of the malaria mosquito Anopheles gambiae experience high mortality, but its cause is poorly understood. Here we study the impact of rainfall, one of the abiotic factors to which the immatures are frequently exposed, on their mortality. We show that rainfall significantly affected larval mosquitoes by flushing them out of their aquatic habitat and killing them. Outdoor experiments under natural conditions in Kenya revealed that the additional nightly loss of larvae caused by rainfall was on average 17.5% for the youngest (L1) larvae and 4.8% for the oldest (L4) larvae; an additional 10.5% (increase from 0.9 to 11.4%) of the L1 larvae and 3.3% (from 0.1 to 3.4%) of the L4 larvae were flushed away and larval mortality increased by 6.9% (from 4.6 to 11.5%) and 1.5% (from 4.1 to 5.6%) for L1 and L4 larvae, respectively, compared to nights without rain. On rainy nights, 1.3% and 0.7% of L1 and L4 larvae, respectively, were lost due to ejection from the breeding site. This study demonstrates that immature populations of malaria mosquitoes suffer high losses during rainfall events. As these populations are likely to experience several rain showers during their lifespan, rainfall will have a profound effect on the productivity of mosquito breeding sites and, as a result, on the transmission of malaria. These findings are discussed in the light of malaria risk and changing rainfall patterns in response to climate change.

Austro-Asiatic Tribes of Northeast India Provide Hitherto Missing Genetic Link between South and Southeast Asia:

Northeast India, the only region which currently forms a land bridge between the Indian subcontinent and Southeast Asia, has been proposed as an important corridor for the initial peopling of East Asia. Given that the Austro-Asiatic linguistic family is considered to be the oldest and spoken by certain tribes in India, Northeast India and entire Southeast Asia, we expect that populations of this family from Northeast India should provide the signatures of genetic link between Indian and Southeast Asian populations. In order to test this hypothesis, we analyzed mtDNA and Y-Chromosome SNP and STR data of the eight groups of the Austro-Asiatic Khasi from Northeast India and the neighboring Garo and compared with that of other relevant Asian populations. The results suggest that the Austro-Asiatic Khasi tribes of Northeast India represent a genetic continuity between the populations of South and Southeast Asia, thereby advocating that northeast India could have been a major corridor for the movement of populations from India to East/Southeast Asia.

Population Response to Habitat Fragmentation in a Stream-Dwelling Brook Trout Population:

Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameterize a size-class and location-based population projection model, allowing us to test effects of fragmentation on population dynamics at local (i.e., subpopulation) and system-wide (i.e., metapopulation) scales, and to identify demographic rates which influence the persistence of isolated and fragmented populations. In the naturally-isolated tributary, persistence was associated with higher early juvenile survival (~45% greater), shorter generation time (one-half) and strong selection against large body size compared to the open system, resulting in a stage-distribution skewed towards younger, smaller fish. Simulating barriers to upstream migration into two currently-connected tributary populations caused rapid (2-6 generations) local extinction. These local extinctions in turn increased the likelihood of system-wide extinction, as tributaries could no longer function as population sources. Extinction could be prevented in the open system if sufficient immigrants from downstream areas were available, but the influx of individuals necessary to counteract fragmentation effects was high (7-46% of the total population annually). In the absence of sufficient immigration, a demographic change (higher early survival characteristic of the isolated tributary) was also sufficient to rescue the population from fragmentation, suggesting that the observed differences in size distributions between the naturally-isolated and open system may reflect an evolutionary response to isolation. Combined with strong genetic divergence between the isolated tributary and open system, these results suggest that local adaptation can ‘rescue’ isolated populations, particularly in one-dimensional stream networks where both natural and anthropogenically-mediated isolation is common. However, whether rescue will occur before extinction depends critically on the race between adaptation and reduced survival in response to fragmentation.

Randomised, Controlled, Assessor Blind Trial Comparing 4% Dimeticone Lotion with 0.5% Malathion Liquid for Head Louse Infestation:

Malathion 0.5% has been the most prescribed pediculicide in the United Kingdom for around 10 years, and is widely used in Europe and North America. Anecdotal reports suggest malathion treatments are less effective than formerly, but this has not been confirmed clinically. This study was designed to determine whether malathion is still effective and if 4% dimeticone lotion is a more effective treatment for head louse infestation. We designed this study as an assessor blinded, randomised, controlled, parallel group trial involving 58 children and 15 adults with active head louse infestation. Each participant received two applications 7 days apart of either 4% dimeticone lotion, applied for 8 hours or overnight, or 0.5% malathion liquid applied for 12 hours or overnight. All treatment and check-up visits were conducted in participants’ homes. Cure of infestation was defined as no evidence of head lice after the second treatment. Some people were found free from lice but later reinfested. Worst case, intention to treat, analysis found dimeticone was significantly more effective than malathion, with 30/43 (69.8%) participants cured using dimeticone compared with 10/30 (33.3%) using malathion (p<0.01, difference 36.4%, 95% confidence interval 14.7% to 58.2%). Per protocol analysis showed cure rates of 30/39 (76.9%) and 10/29 (34.5%) respectively. Irritant reactions were observed in only two participants, both treated with malathion. We concluded that, although malathion liquid is still effective for some people, dimeticone lotion offers a significantly more effective alternative treatment for most people.

Thermal Disruption of Mushroom Body Development and Odor Learning in Drosophila:

Environmental stress (nutritive, chemical, electromagnetic and thermal) has been shown to disrupt central nervous system (CNS) development in every model system studied to date. However, empirical linkages between stress, specific targets in the brain, and consequences for behavior have rarely been established. The present study experimentally demonstrates one such linkage by examining the effects of ecologically-relevant thermal stress on development of the Drosophila melanogaster mushroom body (MB), a conserved sensory integration and associative center in the insect brain. We show that a daily hyperthermic episode throughout larval and pupal development (1) severely disrupts MB anatomy by reducing intrinsic Kenyon cell (KC) neuron numbers but has little effect on other brain structures or general anatomy, and (2) greatly impairs associative odor learning in adults, despite having little effect on memory or sensory acuity. Hence, heat stress of ecologically relevant duration and intensity can impair brain development and learning potential.

How Global Is the Global Biodiversity Information Facility?:

There is a concerted global effort to digitize biodiversity occurrence data from herbarium and museum collections that together offer an unparalleled archive of life on Earth over the past few centuries. The Global Biodiversity Information Facility provides the largest single gateway to these data. Since 2004 it has provided a single point of access to specimen data from databases of biological surveys and collections. Biologists now have rapid access to more than 120 million observations, for use in many biological analyses. We investigate the quality and coverage of data digitally available, from the perspective of a biologist seeking distribution data for spatial analysis on a global scale. We present an example of automatic verification of geographic data using distributions from the International Legume Database and Information Service to test empirically, issues of geographic coverage and accuracy. There are over 1/2 million records covering 31% of all Legume species, and 84% of these records pass geographic validation. These data are not yet a global biodiversity resource for all species, or all countries. A user will encounter many biases and gaps in these data which should be understood before data are used or analyzed. The data are notably deficient in many of the world’s biodiversity hotspots. The deficiencies in data coverage can be resolved by an increased application of resources to digitize and publish data throughout these most diverse regions. But in the push to provide ever more data online, we should not forget that consistent data quality is of paramount importance if the data are to be useful in capturing a meaningful picture of life on Earth.

As always, go and read, rate, comment, annotate and trackback your blog posts….

Circadian Disorders And Adjusting To The Night Shift: Guide For Professionals:

Practice parameters are a guide to the appropriate assessment and treatment of circadian rhythm sleep disorders (CRSDs). The standards will have a positive impact on professional behavior, patient outcomes and possibly health care costs.

Sleep-related Breathing Disorder Linked To Increased Heart Rate Variability:

A sleep-related breathing disorder, common in heart failure, increases one’s heart rate variability. Further, central sleep apnea (CSA) and obstructive sleep apnea (OSA) produce different patterns of heart rate variability, which are likely to reflect the different pathophysiological mechanisms involved, according to a new study.

For Migrating Sparrows, Kids Have A Compass, But Adults Have The Map:

Even bird brains can get to know an entire continent — but it takes them a year of migration to do so, suggests a Princeton research team.

Smell You Later: Scientists Reveal How Mice Recognize Each Other:

Scientists at the University of Liverpool have discovered that mice rely on a special set of proteins to recognise each other. Previous study assumed that another set of genes that influence smell in vertebrates might be used by animals that identify each other through scent. The team found, however, that mice use a highly specialised set of proteins in their urine to recognise different individuals, suggesting that this may also be true of other animals.

New Species Of Peccary –pig-like Animal — Discovered In Amazon Region:

Dutch biologist Marc van Roosmalen has discovered a new species of peccary, a member of the pig family, in the basin of the Rio Aripuanã in the south-eastern Amazon region. The divergence time from the already known peccary species (the time which has passed since the evolutionary division) has been set at one to 1.2 million years.

Mice Influenced By Traumatic ‘Childhood’ Experiences:

How does the experience of traumatic stress in childhood affect one’s life in subsequent years? Leo Enthoven, a PhD student at the Leiden / Amsterdam Center for Drug Research (LACDR) and Leiden University Medical Center (LUMC) studied this subject in a laboratory animal model. He has achieved some remarkable results with mice, but cannot yet say anything about humans.

Tiger Numbers Could Be Doubled In South Asia:

Researchers at the Wildlife Conservation Society and other institutions declare that improvements in management of existing protected areas in South Asia could double the number of tigers currently existing in the region.

All Male or All Female Litter? Sex-ratio Meiotic Drive System Identified In Fruit Flies:

If you met a person who had 10 children, all of whom were girls, you would probably find this surprising. Yet this kind of distorted sex ratio does occur in groups as diverse as mammals, insects, and plants, where some parents consistently produce litters in which the sex ratio is dramatically skewed.

Rest For The Racehorse After Exercise:

Equine muscle glycogen stores require sufficient time for post-exercise repletion. Repletion cannot be hastened in any way other than rest.

Earliest Birds Acted More Like Turkeys Than Common Cuckoos:

The earliest birds acted more like turkeys than common cuckoos, according to a new report. By comparing the claw curvatures of ancient and modern birds, the researchers provide new evidence that the evolutionary ancestors of birds primarily made their livings on the ground rather than in trees.

Flying Lemurs Are The Closest Relatives Of Primates:

While the human species is unquestionably a member of the Primate group, the identity of the next closest group to primates within the entire class of living mammals has been hotly debated. Now, new molecular and genomic data gathered by a team including Webb Miller, a professor of biology and computer science and engineering at the Penn State University, has shown that the colugos — nicknamed the flying lemurs — is the closest group to the primates.

Anne-Marie has more.
Fossil Record Reveals Elusive Jellyfish More Than 500 Million Years Old:

Using recently discovered “fossil snapshots” found in rocks more than 500 million years old, three University of Kansas researchers have described the oldest definitive jellyfish ever found.

How Old Tree Rings And Ancient Wood Are Helping Rewrite History:

Cornell archaeologists are rewriting history with the help of tree rings from 900-year-old trees, wood found on ancient buildings and through analysis of the isotopes (especially radiocarbon dating) and chemistry they can find in that wood.

Burrowing Mammals Dig For A Living, But How Do They Do That?:

Next time you see a mole digging in tree-root-filled soil in search of supper, take a moment to ponder the mammal’s humerus bones. When seen in the lab, they are nothing like the long upper arm bones of any other mammal, says Samantha Hopkins, a paleontologist at the University of Oregon.

Hanging Around With Lemurs, The Planet’s Most Primitive Primates:

Nayuta Yamashita’s office is in the Alan Hancock Foundation Building, right in the heart of USC’s campus. But her lab, in the truest sense, is halfway around the world.

Tangled Web Of The Insect, Plant And Parasite Arms Race:

New insights into the evolutionary relationship between plant-dwelling insects and their parasites are revealed in the online open access journal BMC Biology. Researchers shed light on how sawflies evolved to escape their parasites and gain themselves an ‘enemy-free space’ for millions of years.

Fossilized Spider, 50 Million Years Old, Clear As Life:

A 50-million-year-old fossilised spider has been brought back to life in stunning 3D by a scientist at The University of Manchester.

Fossilized Body Imprints Of Amphibians Found In 330 Million-year-old Rocks:

Unprecedented fossilized body imprints of amphibians have been discovered in 330 million-year-old rocks from Pennsylvania. The imprints show the unmistakably webbed feet and bodies of three previously unknown, foot-long salamander-like critters that lived 100 million years before the first dinosaurs.

Volcanic Eruptions, Not Meteor, May Have Killed The Dinosaurs:

A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico. The eruptions, which created the gigantic Deccan Traps lava beds of India, are now the prime suspect in the most famous and persistent paleontological murder mystery, say scientists who have conducted a slew of new investigations honing down eruption timing.

Genetics Of Coat Color In Dogs May Help Explain Human Stress And Weight:

A discovery about the genetics of coat color in dogs could help explain why humans come in different weights and vary in our abilities to cope with stress, a team led by researchers from the Stanford University School of Medicine reports.

Drug Commonly Used To Treat Bipolar Disorder Dramatically Increases Lifespan In Worms:

Nematode worms treated with lithium show a 46 percent increase in lifespan, raising the tantalizing question of whether humans taking the mood affecting drug are also taking an anti-aging medication.

Whales For The Saving: Research Demonstrates Need For Speed Restrictions:

Dal research demonstrates need for speed restrictions to protect North Atlantic Right Whales in Canadian waters. There are less than 400 of them left in the world, and many of them travel to Canadian waters each year to feed. The North Atlantic Right Whale is one of the most endangered whales in the world.

Efficient Crowd Control In Bacterial Colonies:

Bacterial cells form colonies with complex organization (aka biofilms), particularly in response to hostile environmental conditions. Recent studies have shown that biofilm development occurs when bacterial cells seek out small cavities and populate them at high densities.

Rosemary Chicken Protects Your Brain From Free Radicals:

Rosemary not only tastes good in culinary dishes such as Rosemary chicken and lamb, but scientists have now found it is also good for your brain. A collaborative group from the Burnham Institute for Medical Research (Burnham Institute) in La Jolla, CA and in Japan, report that the herb rosemary contains an ingredient that fights off free radical damage in the brain.

Big Fossil ‘Raptor’ Tracks Show Group Behavior:

Everyone knows that “raptor” dinosaurs walked with their deadly sickle-shaped foot claws held off the ground and that they moved in packs … right? After all, it was in “Jurassic Park.” But until now, there was no direct evidence of either of these things. Now, an international team of Chinese, British, American and Japanese paleontologists reported fossilized footprints made by two different kinds of “raptors” from 120 million year old rocks in Shandong Province, China.

Resistance To Thoughts Of Chocolate Is Futile:

A research project carried out by a University of Hertfordshire academic has found that thought suppression can lead people to engage in the very behaviour they are trying to avoid. It also found that men who think about chocolate end up eating more of it than women who have the same thoughts.

Primates: Extinction Threat Growing For Mankind’s Closest Living Relatives:

Mankind’s closest living relatives — the world’s apes, monkeys, lemurs and other primates — are under unprecedented threat from destruction of tropical forests, illegal wildlife trade and commercial bushmeat hunting, with 29 percent of all species in danger of going extinct, according to a new report.

Why Do Autumn Leaves Turn Red? Soil May Dictate Fall Colors:

Soils may dictate the array of fall colors as much as the trees rooted in them, according to a forest survey out of North Carolina.

Social Standing Influences Elephant Movement:

When resources are scarce, who you know and where you’re positioned on the social totem pole affects how far you’ll go to search for food. At least that’s the case with African elephants, according to a study led by ecologists at the University of California, Berkeley, who collaborated with researchers at Save the Elephants, a non-profit research organization based in Kenya, and at the University of Oxford in England.

Longest Living Animal? Clam — 400 Years Old — Found In Icelandic Waters:

A clam dredged from Icelandic waters had lived for 400 years – is this the longest-lived animal known to science?