A Blog Around The Clock

Now that PLoS ONE is publishing daily (OK, not really, only on work-days, i.e., 5 times a week), I have been pointing to my picks every day. Let’s look at what has been published there last night and tonight as well as what’s new in other PLoS journals. As always, you should rate the articles, post notes and comments and send trackbacks when you blog about the papers.
Courtship Initiation Is Stimulated by Acoustic Signals in Drosophila melanogaster:

Finding a mating partner is a critical task for many organisms. It is in the interest of males to employ multiple sensory modalities to search for females. In Drosophila melanogaster, vision is thought to be the most important courtship stimulating cue at long distance, while chemosensory cues are used at relatively short distance. In this report, we show that when visual cues are not available, sounds produced by the female allow the male to detect her presence in a large arena. When the target female was artificially immobilized, the male spent a prolonged time searching before starting courtship. This delay in courtship initiation was completely rescued by playing either white noise or recorded fly movement sounds to the male, indicating that the acoustic and/or seismic stimulus produced by movement stimulates courtship initiation, most likely by increasing the general arousal state of the male. Mutant males expressing tetanus toxin (TNT) under the control of Gr68a-GAL4 had a defect in finding active females and a delay in courtship initiation in a large arena, but not in a small arena. Gr68a-GAL4 was found to be expressed pleiotropically not only in putative gustatory pheromone receptor neurons but also in mechanosensory neurons, suggesting that Gr68a-positive mechanosensory neurons, not gustatory neurons, provide motion detection necessary for courtship initiation. TNT/Gr68a males were capable of discriminating the copulation status and age of target females in courtship conditioning, indicating that female discrimination and formation of olfactory courtship memory are independent of the Gr68a-expressing neurons that subserve gustation and mechanosensation. This study suggests for the first time that mechanical signals generated by a female fly have a prominent effect on males’ courtship in the dark and leads the way to studying how multimodal sensory information and arousal are integrated in behavioral decision making.

Hyaluronidase of Bloodsucking Insects and Its Enhancing Effect on Leishmania Infection in Mice:

Hyaluronidases are enzymes degrading the extracellular matrix of vertebrates. Bloodsucking insects use them to cleave the skin of the host, enlarge the feeding lesion and acquire the blood meal. In addition, resulting fragments of extracellular matrix modulate local immune response of the host, which may positively affect transmission of vector-borne diseases, including leishmaniasis. Leishmaniases are diseases with a wide spectrum of clinical forms, from a relatively mild cutaneous affection to life-threatening visceral disease. Their causative agents, protozoans of the genus Leishmania, are transmitted by phlebotomine sand flies. Sand fly saliva was described to enhance Leishmania infection, but the information about molecules responsible for this exacerbating effect is still very limited. In the present work we demonstrated hyaluronidase activity in salivary glands of various Diptera and in fleas. In addition, we showed that hyaluronidase exacerbates Leishmania lesions in mice and propose that salivary hyaluronidase may facilitate the spread of other vector-borne microorganisms.

A Publish-Subscribe Model of Genetic Networks:

We present a simple model of genetic regulatory networks in which regulatory connections among genes are mediated by a limited number of signaling molecules. Each gene in our model produces (publishes) a single gene product, which regulates the expression of other genes by binding to regulatory regions that correspond (subscribe) to that product. We explore the consequences of this publish-subscribe model of regulation for the properties of single networks and for the evolution of populations of networks. Degree distributions of randomly constructed networks, particularly multimodal in-degree distributions, which depend on the length of the regulatory sequences and the number of possible gene products, differed from simpler Boolean NK models. In simulated evolution of populations of networks, single mutations in regulatory or coding regions resulted in multiple changes in regulatory connections among genes, or alternatively in neutral change that had no effect on phenotype. This resulted in remarkable evolvability in both number and length of attractors, leading to evolved networks far beyond the expectation of these measures based on random distributions. Surprisingly, this rapid evolution was not accompanied by changes in degree distribution; degree distribution in the evolved networks was not substantially different from that of randomly generated networks. The publish-subscribe model also allows exogenous gene products to create an environment, which may be noisy or stable, in which dynamic behavior occurs. In simulations, networks were able to evolve moderate levels of both mutational and environmental robustness.

[11C]CHIBA-1001 as a Novel PET Ligand for α7 Nicotinic Receptors in the Brain: A PET Study in Conscious Monkeys:

The α7 nicotinic acetylcholine receptors (nAChRs) play an important role in the pathophysiology of neuropsychiatric diseases such as schizophrenia and Alzheimer’s disease. However, there are currently no suitable positron emission tomography (PET) radioligands for imaging α7 nAChRs in the intact human brain. Here we report the novel PET radioligand [11C]CHIBA-1001 for in vivo imaging of α7 nAChRs in the non-human primate brain. A receptor binding assay showed that CHIBA-1001 was a highly selective ligand at α7 nAChRs. Using conscious monkeys, we found that the distribution of radioactivity in the monkey brain after intravenous administration of [11C]CHIBA-1001 was consistent with the regional distribution of α7 nAChRs in the monkey brain. The distribution of radioactivity in the brain regions after intravenous administration of [11C]CHIBA-1001 was blocked by pretreatment with the selective α7 nAChR agonist SSR180711 (5.0 mg/kg). However, the distribution of [11C]CHIBA-1001 was not altered by pretreatment with the selective α4β2 nAChR agonist A85380 (1.0 mg/kg). Interestingly, the binding of [11C]CHIBA-1001 in the frontal cortex of the monkey brain was significantly decreased by subchronic administration of the N-methyl-D-aspartate (NMDA) receptor antagonist phencyclidine (0.3 mg/kg, twice a day for 13 days); which is a non-human primate model of schizophrenia. The present findings suggest that [11C]CHIBA-1001 could be a novel useful PET ligand for in vivo study of the receptor occupancy and pathophysiology of α7 nAChRs in the intact brain of patients with neuropsychiatric diseases such as schizophrenia and Alzheimer’s disease.

Toward Comprehensive Interventions to Improve the Health of Women of Reproductive Age:

In lesser-developed countries (LDCs), the causes of anaemia during pregnancy are multi-factorial, yet much of the aetiological fraction of disease is attributable to a few entities. Iron deficiency is the most common cause of anaemia among pregnant women, resulting from both dietary insufficiency of iron as well as losses through the gastrointestinal tract. These losses are largely due to hookworm infection, but schistosomiasis at higher intensities of infection may also lead to blood loss [1].
The argument for hookworm treatment during pregnancy as proposed by Brooker et al. [2] and the WHO [3] is based largely on expected consequences of hookworm-related iron deficiency anaemia for both mother and newborn. It is beyond the scope of this commentary to address the complex relationship between hemoglobin levels assessed at different stages of pregnancy and peri-natal morbidity [4]. However, the relationship between iron status early in pregnancy and birth outcomes is clearer and more relevant here. It is fairly well established that iron deficiency anaemia present during the first trimester of pregnancy is associated with a 2-fold risk of low birth weight [5]. This risk is much lower among women with non-iron deficiency anaemia during the first trimester, arguing for an important mechanistic role for iron per se, discussed in greater detail in recent reviews [6]. In addition to its effects on birth weight, transfer of iron to the developing fetus is compromised among women with depleted iron stores [7]. Maternal iron deficiency is related to decreased newborn and infant iron stores, as well as increased risk of anaemia during infancy [4]. Given the established relationship between hookworm and iron deficiency, hookworm treatment is likely to positively affect maternal and infant health, though the timing of treatment as well as provision of micro-nutrient supplementation are key factors discussed further below.

It’s All In The Hips: Early Whales Used Well Developed Back Legs For Swimming, Fossils Show:

The crashing of the enormous fluked tail on the surface of the ocean is a “calling card” of modern whales. Living whales have no back legs, and their front legs take the form of flippers that allow them to steer. Their special tails provide the powerful thrust necessary to move their huge bulk. Yet this has not always been the case.

Researchers Suppress ‘Hunger Hormone’ In Pigs: New Minimally Invasive Method Yields Result As Good As Bariatric Surgery:

Johns Hopkins scientists report success in significantly suppressing levels of the “hunger hormone” ghrelin in pigs using a minimally invasive means of chemically vaporizing the main vessel carrying blood to the top section, or fundus, of the stomach. An estimated 90 percent of the body’s ghrelin originates in the fundus, which can’t make the hormone without a good blood supply.

Report Offers Advice To McCain, Obama On Science And Technology Appointments:

The importance of research in solving many of our national challenges, including economic ones, is emphasized in a new report titled Science and Technology for America’s Progress: Ensuring the Best Presidential Appointments in the New Administration.

Signals From Blood Of Mother Enhance Maturation Of Brain:

The maturation of the brain of unborn infants is given a gentle “prod” by its mother. A protein messenger from the mother’s blood is transferred to the embryo and stimulates the growth and wiring of the neurons in the brain.

Almost 7 Million Pregnant In Sub-Saharan Africa Infected With Hookworms:

A study published in the open-access journal PLoS Neglected Tropical Diseases reveals that between a quarter and a third of pregnant women in sub-Saharan Africa, or almost 7 million, are infected with hookworms and at increased risk of developing anaemia.

Blanket Ban On Bushmeat Could Be Disastrous For Forest Dwellers In Central Africa, Says New Report:

A new report from the Center for International Forestry Research (CIFOR), the Secretariat of the Convention on Biological Diversity (CDB) and partners warns that an upsurge in hunting bushmeat–including mammals, birds, reptiles and amphibians — in tropical forests is unsustainable and that it poses serious threats to food security for poor inhabitants of forests in Africa, who rely largely on bushmeat for protein.

Criminals Who Eat Processed Foods More Likely To Be Discovered, Through Fingerprint Sweat Corroding Metal:

The inventor of a revolutionary new forensic fingerprinting technique claims criminals who eat processed foods are more likely to be discovered by police through their fingerprint sweat corroding metal.

Scientists Behind ‘Doomsday Seed Vault’ Ready World’s Crops For Climate Change:

As climate change is credited as one of the main drivers behind soaring food prices, the Global Crop Diversity Trust is undertaking a major effort to search crop collections–from Azerbaijan to Nigeria–for the traits that could arm agriculture against the impact of future changes. Traits, such as drought resistance in wheat, or salinity tolerance in potato, will become essential as crops around the world have to adapt to new climate conditions.

The Greening Of Sub-Saharan Africa:

The green revolution that has led to food being far more abundant now than forty years ago in South America and Asia has all-but bypasses Sub-Saharan Africa as that region’s population trebled over that time period.

Fastest Flights In Nature: High-speed Spore Discharge Mechanisms Among Fungi:

Microscopic coprophilous or dung-loving fungi help make our planet habitable by degrading the billions of tons of feces produced by herbivores. But the fungi have a problem: survival depends upon the consumption of their spores by herbivores and few animals will graze on grass next to their own dung.

Also check this, this, this, this and this.
Watch And Learn: Time Teaches Us How To Recognize Visual Objects:

In work that could aid efforts to develop more brain-like computer vision systems, MIT neuroscientists have tricked the visual brain into confusing one object with another, thereby demonstrating that time teaches us how to recognize objects.

Photosynthesizing Bacteria With A Day-night Cycle Contain Rare Chromosome:

Researchers sequencing the DNA of blue-green algae found a linear chromosome harboring genes important for producing biofuels. Simultaneously analyzing the complement of proteins revealed more genes on the linear and the typical circular chromosomes then they’d have found with DNA sequencing alone.

Replacing The Coach Doesn’t Solve Problems:

Bringing in a new coach rarely solves problems, regardless of when it is done. This is the conclusion of a study from Mid Sweden University about hiring and firing coaches in the Swedish Elite Series ice-hockey league during the period 1975/76-2005/06. Despite this fact, coaches are nevertheless very publicly fired. The study shows that it is a mistake to replace the coach.

Consumers Think Differently About Close And Distant Purchases:

If you are deciding on a major vacation for next year, you’ll use different criteria than if you are planning a trip this weekend, according to a new study in the Journal of Consumer Research.

New Insights Into Teenagers And Anxiety Disorders:

Can scientists predict who will develop anxiety disorders years in advance? UCLA psychology professor Michelle Craske thinks so. She is four years into an eight-year study evaluating 650 students, who were 16 when the study began, to identify risk factors for the development of anxiety and depression — the most comprehensive study of its kind.

Seize The Day! New Research Helps Tightwads ‘Live A Little’:

Some people have trouble indulging, and they regret it later. There’s hope for those people, according to a new study.

New Music Software Can Create Accompaniment To Any Melody, In Style Of Any Artist:

It’s an archetypal exchange in musical performance. A vocalist stands poised to perform. The guitarist alongside is ready to add depth and harmony to the melody.

There are 9 new articles in PLoS ONE today and all nine are amazing and quite bloggable (hint, hint).
As always, you should rate the articles, post notes and comments and send trackbacks when you blog about the papers. Here are my own picks for the week – you go and look for your own favourites:
The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi:

A variety of spore discharge processes have evolved among the fungi. Those with the longest ranges are powered by hydrostatic pressure and include “squirt guns” that are most common in the Ascomycota and Zygomycota. In these fungi, fluid-filled stalks that support single spores or spore-filled sporangia, or cells called asci that contain multiple spores, are pressurized by osmosis. Because spores are discharged at such high speeds, most of the information on launch processes from previous studies has been inferred from mathematical models and is subject to a number of errors. In this study, we have used ultra-high-speed video cameras running at maximum frame rates of 250,000 fps to analyze the entire launch process in four species of fungi that grow on the dung of herbivores. For the first time we have direct measurements of launch speeds and empirical estimates of acceleration in these fungi. Launch speeds ranged from 2 to 25 m s−1 and corresponding accelerations of 20,000 to 180,000 g propelled spores over distances of up to 2.5 meters. In addition, quantitative spectroscopic methods were used to identify the organic and inorganic osmolytes responsible for generating the turgor pressures that drive spore discharge. The new video data allowed us to test different models for the effect of viscous drag and identify errors in the previous approaches to modeling spore motion. The spectroscopic data show that high speed spore discharge mechanisms in fungi are powered by the same levels of turgor pressure that are characteristic of fungal hyphae and do not require any special mechanisms of osmolyte accumulation.

Watch the accompanying movie – it is astonishing!

Also see Carl Zimmer’s take on the paper. And re-visit my old post on the topic.
Female-Biased Dispersal and Gene Flow in a Behaviorally Monogamous Mammal, the Large Treeshrew (Tupaia tana):

Female-biased dispersal (FBD) is predicted to occur in monogamous species due to local resource competition among females, but evidence for this association in mammals is scarce. The predicted relationship between FBD and monogamy may also be too simplistic, given that many pair-living mammals exhibit substantial extra-pair paternity. I examined whether dispersal and gene flow are female-biased in the large treeshrew (Tupaia tana) in Borneo, a behaviorally monogamous species with a genetic mating system characterized by high rates (50%) of extra-pair paternity. Genetic analyses provided evidence of FBD in this species. As predicted for FBD, I found lower mean values for the corrected assignment index for adult females than for males using seven microsatellite loci, indicating that female individuals were more likely to be immigrants. Adult female pairs were also less related than adult male pairs. Furthermore, comparison of Bayesian coalescent-based estimates of migration rates using maternally and bi-parentally inherited genetic markers suggested that gene flow is female-biased in T. tana. The effective number of migrants between populations estimated from mitochondrial DNA sequence was three times higher than the number estimated using autosomal microsatellites. These results provide the first evidence of FBD in a behaviorally monogamous species without mating fidelity. I argue that competition among females for feeding territories creates a sexual asymmetry in the costs and benefits of dispersal in treeshrews.

Population and Individual Elephant Response to a Catastrophic Fire in Pilanesberg National Park:

In predator-free large herbivore populations, where density-dependent feedbacks occur at the limit where forage resources can no longer support the population, environmental catastrophes may play a significant role in population regulation. The potential role of fire as a stochastic mass-mortality event limiting these populations is poorly understood, so too the behavioural and physiological responses of the affected animals to this type of large disturbance event. During September 2005, a wildfire resulted in mortality of 29 (18% population mortality) and injury to 18, African elephants in Pilanesberg National Park, South Africa. We examined movement and herd association patterns of six GPS-collared breeding herds, and evaluated population physiological response through faecal glucocorticoid metabolite (stress) levels. We investigated population size, structure and projected growth rates using a simulation model. After an initial flight response post-fire, severely injured breeding herds reduced daily displacement with increased daily variability, reduced home range size, spent more time in non-tourist areas and associated less with other herds. Uninjured, or less severely injured, breeding herds also shifted into non-tourist areas post-fire, but in contrast, increased displacement rate (both mean and variability), did not adjust home range size and formed larger herds post-fire. Adult cow stress hormone levels increased significantly post-fire, whereas juvenile and adult bull stress levels did not change significantly. Most mortality occurred to the juvenile age class causing a change in post-fire population age structure. Projected population growth rate remained unchanged at 6.5% p.a., and at current fecundity levels, the population would reach its previous level three to four years post-fire. The natural mortality patterns seen in elephant populations during stochastic events, such as droughts, follows that of the classic mortality pattern seen in predator-free large ungulate populations, i.e. mainly involving juveniles. Fire therefore functions in a similar manner to other environmental catastrophes and may be a natural mechanism contributing to population limitation. Welfare concerns of arson fires, burning during “hot-fire” conditions and the conservation implications of fire suppression (i.e. removal of a potential contributing factor to natural population regulation) should be integrated into fire management strategies for conservation areas.

Selective Breeding for a Behavioral Trait Changes Digit Ratio:

The ratio of the length of the second digit (index finger) divided by the fourth digit (ring finger) tends to be lower in men than in women. This 2D:4D digit ratio is often used as a proxy for prenatal androgen exposure in studies of human health and behavior. For example, 2D:4D ratio is lower (i.e. more “masculinized”) in both men and women of greater physical fitness and/or sporting ability. Lab mice have also shown variation in 2D:4D as a function of uterine environment, and mouse digit ratios seem also to correlate with behavioral traits, including daily activity levels. Selective breeding for increased rates of voluntary exercise (wheel running) in four lines of mice has caused correlated increases in aerobic exercise capacity, circulating corticosterone level, and predatory aggression. Here, we show that this selection regime has also increased 2D:4D. This apparent “feminization” in mice is opposite to the relationship seen between 2D:4D and physical fitness in human beings. The present results are difficult to reconcile with the notion that 2D:4D is an effective proxy for prenatal androgen exposure; instead, it may more accurately reflect effects of glucocorticoids, or other factors that regulate any of many genes.

Updated Three-Stage Model for the Peopling of the Americas:

We re-assess support for our three stage model for the peopling of the Americas in light of a recent report that identified nine non-Native American mitochondrial genome sequences that should not have been included in our initial analysis. Removal of these sequences results in the elimination of an early (i.e. ~40,000 years ago) expansion signal we had proposed for the proto-Amerind population. Bayesian skyline plot analysis of a new dataset of Native American mitochondrial coding genomes confirms the absence of an early expansion signal for the proto-Amerind population and allows us to reduce the variation around our estimate of the New World founder population size. In addition, genetic variants that define New World founder haplogroups are used to estimate the amount of time required between divergence of proto-Amerinds from the Asian gene pool and expansion into the New World. The period of population isolation required for the generation of New World mitochondrial founder haplogroup-defining genetic variants makes the existence of three stages of colonization a logical conclusion. Thus, our three stage model remains an important and useful working hypothesis for researchers interested in the peopling of the Americas and the processes of colonization.

A Reevaluation of the Native American MtDNA Genome Diversity and Its Bearing on the Models of Early Colonization of Beringia:

The Americas were the last continents to be populated by humans, and their colonization represents a very interesting chapter in our species’ evolution in which important issues are still contentious or largely unknown. One difficult topic concerns the details of the early peopling of Beringia, such as for how long it was colonized before people moved into the Americas and the demography of this occupation. A recent work using mitochondrial genome (mtDNA) data presented evidence for a so called “three-stage model” consisting of a very early expansion into Beringia followed by ~20,000 years of population stability before the final entry into the Americas. However, these results are in disagreement with other recent studies using similar data and methods. Here, we reanalyze their data to check the robustness of this model and test the ability of Native American mtDNA to discriminate details of the early colonization of Beringia. We apply the Bayesian Skyline Plot approach to recover the past demographic dynamic underpinning these events using different mtDNA data sets. Our results refute the specific details of the “three-stage model”, since the early stage of expansion into Beringia followed by a long period of stasis could not be reproduced in any mtDNA data set cleaned from non-Native American haplotypes. Nevertheless, they are consistent with a moderate population bottleneck in Beringia associated with the Last Glacial Maximum followed by a strong population growth around 18,000 years ago as suggested by other recent studies. We suggest that this bottleneck erased the signals of ancient demographic history from recent Native American mtDNA pool, and conclude that the proposed early expansion and occupation of Beringia is an artifact caused by the misincorporation of non-Native American haplotypes.

Neural Correlates of Perceiving Emotional Faces and Bodies in Developmental Prosopagnosia: An Event-Related fMRI-Study:

Many people experience transient difficulties in recognizing faces but only a small number of them cannot recognize their family members when meeting them unexpectedly. Such face blindness is associated with serious problems in everyday life. A better understanding of the neuro-functional basis of impaired face recognition may be achieved by a careful comparison with an equally unique object category and by a adding a more realistic setting involving neutral faces as well facial expressions. We used event-related functional magnetic resonance imaging (fMRI) to investigate the neuro-functional basis of perceiving faces and bodies in three developmental prosopagnosics (DP) and matched healthy controls. Our approach involved materials consisting of neutral faces and bodies as well as faces and bodies expressing fear or happiness. The first main result is that the presence of emotional information has a different effect in the patient vs. the control group in the fusiform face area (FFA). Neutral faces trigger lower activation in the DP group, compared to the control group, while activation for facial expressions is the same in both groups. The second main result is that compared to controls, DPs have increased activation for bodies in the inferior occipital gyrus (IOG) and for neutral faces in the extrastriate body area (EBA), indicating that body and face sensitive processes are less categorically segregated in DP. Taken together our study shows the importance of using naturalistic emotional stimuli for a better understanding of developmental face deficits.

Arctic Sea Ice At Lowest Recorded Level Ever:

Arctic sea ice may well have reached its lowest volumes ever, as summer ice coverage of the Arctic Sea looks set to be close to last year’s record lows, with thinner ice overall.

How Memories Are Made, And Recalled:

What makes a memory? Single cells in the brain, for one thing. For the first time, scientists at UCLA and the Weizmann Institute of Science in Israel have recorded individual brain cells in the act of calling up a memory, thus revealing where in the brain a specific memory is stored and how the brain is able to recreate it.

Don’t Throw The Candy Out: Temptation Leads To Moderation:

Banishing tempting goodies may not be the best way to keep from eating them. Tempting foods can actually increase willpower, according to new research. Although it seems counterintuitive, consumers show more self-control after they’ve spent some time in the presence of a treat.

Fantastic Photographs Of Fluorescent Fish:

Scientists have discovered that certain fish are capable of glowing red. Due to absorption of ‘red’ wavelengths of sunlight by sea-water, objects which look red under normal conditions appear grey or black at depths below 10m. This has contributed to the belief among marine biologists that red colours are of no importance to fish.

Why Some Primates, But Not Humans, Can Live With Immunodeficiency Viruses And Not Progress To AIDS:

Key differences in immune system signaling and the production of specific immune regulatory molecules may explain why some primates are able to live with an immunodeficiency virus infection without progressing to AIDS-like illness, unlike other primate species, including rhesus macaques and humans, that succumb to disease.

Whale Songs Are Heard For First Time Around New York City Waters:

For the first time in waters surrounding New York City, the beckoning calls of endangered fin, humpback and North Atlantic right whales have been recorded, according to experts from the Bioacoustics Research Program at the Cornell Lab of Ornithology and the New York State Department of Environmental Conservation (DEC).

Houses Made Of Hemp Could Help Combat Climate Change:

Houses made of hemp, timber or straw could help combat climate change by reducing the carbon footprint of building construction, according to researchers at the University of Bath.

Mice Missing ‘Fear’ Gene Slow To Protect Offspring:

First, he discovered a gene that controls innate fear in animals. Now Rutgers geneticist Gleb Shumyatsky has shown that the same gene promotes “helicopter mom” behavior in mice. The gene, known as stathmin or oncoprotein 18, motivates female animals to protect newborn pups and interact cautiously with unknown peers.

Oil Palm Plantations Are No Substitute For Tropical Rainforests, New Study Shows:

The continued expansion of oil palm plantations will worsen the dual environmental crises of climate change and biodiversity loss, unless rainforests are better protected, warn scientists in the most comprehensive review of the subject to date.

A Morning-Specific Phytohormone Gene Expression Program underlying Rhythmic Plant Growth:

In plants, stems elongate faster at dawn. This time-of-day-specific growth is controlled by integration of environmental cues and the circadian clock. The specific effectors of growth in plants are the phytohormones: auxin, ethylene, gibberellins, abscisic acid, brassinosteroids, and cytokinins. Each phytohormone plays an independent as well as an overlapping role in growth, and understanding the interactions of the phytohormones has dominated plant research over the past century. The authors present a model in which the circadian clock coordinates growth by synchronizing phytohormone gene expression at dawn, allowing a plant to control growth in a condition-specific manner. Furthermore, the results presented provide a new framework for future experiments aimed at understanding the integration and crosstalk of the phytohormones.

Informed Consent in the Genomics Era:

Since the Nuremberg trials, informed consent (IC) has been recognized as a basic ethical requirement for research involving human participants [1] (Table 1). Such consent encompasses two distinct elements: (1) researchers communicate detailed information about study procedures, outcomes, risks, and benefits for the participating individual or community, and (2) after understanding and careful consideration, the participants consent to take part under these conditions. However, the suitability of IC for genomic studies has been recently challenged [2,3]. Because the research protocol for such studies may evolve over time, the condition in IC of providing detailed information for a well-defined protocol is not easily satisfied.
Large amounts of data stored as electronic records allow multiple post-hoc analyses, which in many cases were not foreseen at the beginning of a study. The potential for analysis is constantly growing and recently has increased dramatically with the development of high-throughput sequencing and genotyping technologies. More than one million genetic variants of an individual may be determined within hours–and even the full genetic sequence within weeks [3]. Such technical advances expose participants to a new class of risk different from the physical harm usually considered in ethical reviews [4,5]. Release of genetic information could lead to uninsurability, unemployability, discrimination, and the breakdown of family relationships by unintentionally demonstrating missing or unknown relatedness. Moreover, participants usually do not get any direct benefit from the research. All of these concerns raise the question: are IC procedures still in accordance with the currently accepted ethical standards of autonomy, beneficence, and non-maleficence?

There are 9 new articles in PLoS ONE today. As always, you should rate the articles, post notes and comments and send trackbacks when you blog about the papers. Here are my own picks for the week – you go and look for your own favourites:
Snake Cathelicidin from Bungarus fasciatus Is a Potent Peptide Antibiotics:

Cathelicidins are a family of antimicrobial peptides acting as multifunctional effector molecules of innate immunity, which are firstly found in mammalians. Recently, several cathelicidins have also been found from chickens and fishes. No cathelicidins from other non-mammalian vertebrates have been reported. In this work, a cathelicidin-like antimicrobial peptide named cathelicidin-BF has been purified from the snake venoms of Bungarus fasciatus and its cDNA sequence was cloned from the cDNA library, which confirm the presence of cathelicidin in reptiles. As other cathelicidins, the precursor of cathelicidin-BF has cathelin-like domain at the N terminus and carry the mature cathelicidin-BF at the C terminus, but it has an atypical acidic fragment insertion between the cathelin-like domain and the C-terminus. The acidic fragment is similar to acidic domains of amphibian antimicrobial precursors. Phylogenetic analysis revealed that the snake cathelicidin had the nearest evolution relationship with platypus cathelicidin. The secondary structure of cathelicidin-BF investigated by CD and NMR spectroscopy in the presence of the helicogenic solvent TFE is an amphipathic α-helical conformation as many other cathelicidins. The antimicrobial activities of cathelicidin BF against forty strains of microorganisms were tested. Cathelicidin-BF efficiently killed bacteria and some fungal species including clinically isolated drug-resistance microorganisms. It was especially active against Gram-negative bacteria. Furthermore, it could exert antimicrobial activity against some saprophytic fungus. No hemolytic and cytotoxic activity was observed at the dose of up to 400 µg/ml. Cathelicidin-BF could exist stably in the mice plasma for at least 2.5 hours. Discovery of snake cathelicidin with atypical structural and functional characterization offers new insights on the evolution of cathelicidins. Potent, broad spectrum, salt-independent antimicrobial activities make cathelicidin-BF an excellent candidate for clinical or agricultural antibiotics.

Mitochondrial and Nuclear Genes Suggest that Stony Corals Are Monophyletic but Most Families of Stony Corals Are Not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria):

Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ß-tubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent “robust” and “complex” clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils.

How Corals Adapt To Day And Night:

Researchers have uncovered a gene in corals that responds to day/night cycles, which provides some tantalizing clues into how symbiotic corals work together with their plankton partners. Corals are fascinating animals that form the largest biological constructions in the world, sprawling coral reefs that cover less than 0.2 % of the seafloor yet provide habitats for more than 30% of marine life. In shallow waters that don’t have abundant food, corals have developed a close relationship with small photosynthetic critters called dinoflagellates.

Giant Honeybees Use Shimmering ‘Mexican Waves’ To Repel Predatory Wasps:

The phenomenon of “shimmering” in giant honeybees, in which hundreds–or even thousands–of individual honeybees flip their abdomens upwards within a split-second to produce a Mexican Wave-like pattern across the bee nest, has received much interest but both its precise mode of action and its purpose have long remained a mystery.

Newer Antipsychotics No Better Than Older Drug In Treating Child And Adolescent Schizophrenia, Study Finds:

Nearly every child who receives an antipsychotic medicine is first prescribed one of the second-generation, or “atypical” drugs, such as olanzapine and risperidone. However, there has never been evidence that these drugs are more effective than the older, first-generation medications.

The ‘Satellite Navigation’ In Our Brains:

Our brains contain their own navigation system much like satellite navigation (“sat-nav”), with in-built maps, grids and compasses, neuroscientist Dr Hugo Spiers told the BA Festival of Science at the University of Liverpool on September 11.

Economic Value Of Insect Pollination Worldwide Estimated At U.S. $217 Billion:

INRA and CNRS French scientists and a UFZ German scientist found that the worldwide economic value of the pollination service provided by insect pollinators, bees mainly, was €153 billion* in 2005 for the main crops that feed the world.

Zebra Finches Vary Immune Response According To Age, Sex And Costs:

Is it always good to respond maximally when pathogens or disease strike, or should individuals vary their immune response to balance immediate and future costs?

New Ant Species Discovered In The Amazon Likely Represents Oldest Living Lineage Of Ants:

A new species of blind, subterranean, predatory ant discovered in the Amazon rainforest by University of Texas at Austin evolutionary biologist Christian Rabeling is likely a descendant of the very first ants to evolve.

Hotline To The Cowshed:

A wireless measuring system, consisting of sensors and transmission units, helps to keep livestock healthier with a minimum use of resources.