Monthly Archives: July 2008

Missing Link Found Between Circadian Clock And Metabolism:

Two new research studies have discovered a long sought molecular link between our metabolism and components of the internal clock that drives circadian rhythms, keeping us to a roughly 24-hour schedule. The findings appear in the July 25th issue of the journal Cell.

Dinosaurs Did Not Evolve Quickly In Last 50 Million Years, New Dinosaur Super-tree Shows:

It has long been debated whether dinosaurs were part of the ‘Terrestrial Revolution’ that occurred some 100 million years ago during the Cretaceous when birds, mammals, flowering plants, insects and reptiles all underwent a rapid expansion.

Parasites Vastly Outweigh Predators In Estuaries: Could Have Significant Ecological Implications:

In a study of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California, a team of researchers from the University of California, Santa Barbara, the United States Geological Survey, and Princeton University has determined that parasite biomass in those habitats exceeds that of top predators, in some cases by a factor of 20.

Parasitic Worm Infections Increase Susceptibility To AIDS Viruses:

Persons infected with schistosomes, and possibly other parasitic worm infections, may be more likely to become infected with HIV than persons without worm infections, according to a new study.

Glia Guide Brain Development In Worms:

Again and again, experiments confirmed it. Without glia, neurons die. So scientists who wanted to study in living animals what glia — the most abundant brain cells — do for neurons besides keep them alive were out of luck. But now, a breakthrough.

Serious School Failure Is Depressing For Girls, But Not Boys:

Adolescent girls who had a serious school failure by the 12th grade — being expelled, suspended or dropping out — were significantly more likely to have suffered a serious bout of depression at the age of 21 than girls who did not have these problems.

Viagra Works For Antidepressant-related Sexual Dysfunction In Women, Study Suggests:

Women with sexual dysfunction caused by the use of antidepressants experienced a reduction in adverse sexual effects with use of sildenafil, commonly known as the erectile dysfunction medication Viagra, according to a new study.

Age-old Magic Tricks Can Provide Clues For Modern Science:

Revealing the science behind age-old magic tricks will help us better understand how humans see, think, and act, according to researchers at the University of British Columbia and Durham University in the U.K.

Licking Your Wounds: Scientists Isolate Compound In Human Saliva That Speeds Wound Healing:

A report by scientists from The Netherlands identifies a compound in human saliva that greatly speeds wound healing. This research may offer hope to people suffering from chronic wounds related to diabetes and other disorders, as well as traumatic injuries and burns. In addition, because the compounds can be mass produced, they have the potential to become as common as antibiotic creams and rubbing alcohol.

Milkweed’s Evolutionary Approach To Caterpillars: Counter Appetite With Fast Repair:

The adage that your enemies know your weaknesses best is especially true in the case of plants and predators that have co-evolved: As the predators evolve new strategies for attack, plants counter with their own unique defenses.

Controlling Invasive Cane Grass With Wasps?:

Researchers at The University of Texas at Austin will work with the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) to investigate biological control for an invasive cane grass that is choking waterways across North America.

Sex And Lifespan Linked In Worms:

A group of scientists who set out to study sex pheromones in a tiny worm found that the same family of pheromones also controls a stage in the worms’ life cycle, the long-lived dauer larva.

There are 51 new papers in PLoS ONE this week – check them out for stuff you are interested in (and post comments, notes and ratings and send trackbacks), but here are my personal picks:
Sample Size and Precision in NIH Peer Review:

The Working Group on Peer Review of the Advisory Committee to the Director of NIH has recommended that at least 4 reviewers should be used to assess each grant application. A sample size analysis of the number of reviewers needed to evaluate grant applications reveals that a substantially larger number of evaluators are required to provide the level of precision that is currently mandated. NIH should adjust their peer review system to account for the number of reviewers needed to provide adequate precision in their evaluations.

Measuring Co-Authorship and Networking-Adjusted Scientific Impact:

Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. In this competitive environment, the number of authors per paper is increasing and apparently some co-authors don’t satisfy authorship criteria. Listing of individual contributions is still sporadic and also open to manipulation. Metrics are needed to measure the networking intensity for a single scientist or group of scientists accounting for patterns of co-authorship. Here, I define I1 for a single scientist as the number of authors who appear in at least I1 papers of the specific scientist. For a group of scientists or institution, In is defined as the number of authors who appear in at least In papers that bear the affiliation of the group or institution. I1 depends on the number of papers authored Np. The power exponent R of the relationship between I1 and Np categorizes scientists as solitary (R>2.5), nuclear (R = 2.25-2.5), networked (R = 2-2.25), extensively networked (R = 1.75-2) or collaborators (R<1.75). R may be used to adjust for co-authorship networking the citation impact of a scientist. In similarly provides a simple measure of the effective networking size to adjust the citation impact of groups or institutions. Empirical data are provided for single scientists and institutions for the proposed metrics. Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles.

Circadian Genes Are Expressed during Early Development in Xenopus laevis:

Circadian oscillators are endogenous time-keeping mechanisms that drive twenty four hour rhythmic changes in gene expression, metabolism, hormone levels, and physical activity. We have examined the developmental expression of genes known to regulate circadian rhythms in order to better understand the ontogeny of the circadian clock in a vertebrate. In this study, genes known to function together in part of the core circadian oscillator mechanism (xPeriod1, xPeriod2, and xBmal1) as well as a rhythmic, clock-controlled gene (xNocturnin) were analyzed using in situ hybridization in embryos from neurula to late tailbud stages. Each transcript was present in the developing nervous system in the brain, eye, olfactory pit, otic vesicle and at lower levels in the spinal cord. These genes were also expressed in the developing somites and heart, but at different developmental times in peripheral tissues (pronephros, cement gland, and posterior mesoderm). No difference was observed in transcript levels or localization when similarly staged embryos maintained in cyclic light were compared at two times of day (dawn and dusk) by in situ hybridization. Quantitation of xBmal1 expression in embryonic eyes was also performed using qRT-PCR. Eyes were isolated at dawn, midday, dusk, and midnight (cylic light). No difference in expression level between time-points was found in stage 31 eyes (p = 0.176) but stage 40 eyes showed significantly increased levels of xBmal1 expression at midnight (RQ = 1.98+/−0.094) when compared to dawn (RQ = 1+/−0.133; p = 0.0004). We hypothesize that when circadian genes are not co-expressed in the same tissue during development that it may indicate pleiotropic functions of these genes that are separate from the timing of circadian rhythm. Our results show that all circadian genes analyzed thus far are present during early brain and eye development, but rhythmic gene expression in the eye is not observed until after stage 31 of development.

Disturbed Clockwork Resetting in Sharp-1 and Sharp-2 Single and Double Mutant Mice:

The circadian system provides the basis to anticipate and cope with daily recurrent challenges to maintain the organisms’ homeostasis. De-synchronization of circadian feedback oscillators in humans causes ‘jet lag’, likely contributes to sleep – , psychiatric – , metabolic disorders and even cancer. However, the molecular mechanisms leading to the disintegration of tissue-specific clocks are complex and not well understood. Based on their circadian expression and cell culture experiments, the basic Helix-Loop-Helix (bHLH) transcription factors SHARP-1(Dec2) and SHARP-2(Stra13/Dec1) were proposed as novel negative regulators of the molecular clock. To address their function in vivo, we generated Sharp-1 and Sharp-2 single and double mutant mice. Our experiments reveal critical roles for both factors in regulating period length, tissue-specific control of clock gene expression and entrainment to external cues. Light-pulse experiments and rapid delays of the light-dark cycle (experimental jet lag) unravel complementary functions for SHARP-1 and SHARP-2 in controlling activity phase resetting kinetics. Moreover, we show that SHARP-1 and 2 can serve dual functions as repressors and co-activators of mammalian clock gene expression in a context-specific manner. This correlates with increased amplitudes of Per2 expression in the cortex and liver and a decrease in the suprachiasmatic nucleus (SCN) of double mutant mice. The existence of separate mechanisms regulating phase of entrainment, rhythm amplitude and period length has been postulated before. The differential effects of Sharp-deficiency on rhythmicity and behavioral re-entrainment, coupled to tissue-dependent regulatory functions, provide a new mechanistic basis to further understand the complex process of clock synchronizations.

Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity:

The evolutionary basis for high species diversity in tropical regions of the world remains unresolved. Much research has focused on the biogeography of speciation in the Amazon Basin, which harbors the greatest diversity of terrestrial life. The leading hypotheses on allopatric diversification of Amazonian taxa are the Pleistocene refugia, marine incursion, and riverine barrier hypotheses. Recent advances in the fields of phylogeography and species-distribution modeling permit a modern re-evaluation of these hypotheses. Our approach combines comparative, molecular phylogeographic analyses using mitochondrial DNA sequence data with paleodistribution modeling of species ranges at the last glacial maximum (LGM) to test these hypotheses for three co-distributed species of leafcutter ants (Atta spp.). The cumulative results of all tests reject every prediction of the riverine barrier hypothesis, but are unable to reject several predictions of the Pleistocene refugia and marine incursion hypotheses. Coalescent dating analyses suggest that population structure formed recently (Pleistocene-Pliocene), but are unable to reject the possibility that Miocene events may be responsible for structuring populations in two of the three species examined. The available data therefore suggest that either marine incursions in the Miocene or climate changes during the Pleistocene–or both–have shaped the population structure of the three species examined. Our results also reconceptualize the traditional Pleistocene refugia hypothesis, and offer a novel framework for future research into the area.

Marine Biofilm Bacteria Evade Eukaryotic Predation by Targeted Chemical Defense:

Many plants and animals are defended from predation or herbivory by inhibitory secondary metabolites, which in the marine environment are very common among sessile organisms. Among bacteria, where there is the greatest metabolic potential, little is known about chemical defenses against bacterivorous consumers. An emerging hypothesis is that sessile bacterial communities organized as biofilms serve as bacterial refuge from predation. By testing growth and survival of two common bacterivorous nanoflagellates, we find evidence that chemically mediated resistance against protozoan predators is common among biofilm populations in a diverse set of marine bacteria. Using bioassay-guided chemical and genetic analysis, we identified one of the most effective antiprotozoal compounds as violacein, an alkaloid that we demonstrate is produced predominately within biofilm cells. Nanomolar concentrations of violacein inhibit protozoan feeding by inducing a conserved eukaryotic cell death program. Such biofilm-specific chemical defenses could contribute to the successful persistence of biofilm bacteria in various environments and provide the ecological and evolutionary context for a number of eukaryote-targeting bacterial metabolites.

Changes in Gray Matter Induced by Learning–Revisited:

Recently, activation-dependant structural brain plasticity in humans has been demonstrated in adults after three months of training a visio-motor skill. Learning three-ball cascade juggling was associated with a transient and highly selective increase in brain gray matter in the occipito-temporal cortex comprising the motion sensitive area hMT/V5 bilaterally. However, the exact time-scale of usage-dependant structural changes occur is still unknown. A better understanding of the temporal parameters may help to elucidate to what extent this type of cortical plasticity contributes to fast adapting cortical processes that may be relevant to learning. Using a 3 Tesla scanner and monitoring whole brain structure we repeated and extended our original study in 20 healthy adult volunteers, focussing on the temporal aspects of the structural changes and investigated whether these changes are performance or exercise dependant. The data confirmed our earlier observation using a mean effects analysis and in addition showed that learning to juggle can alter gray matter in the occipito-temporal cortex as early as after 7 days of training. Neither performance nor exercise alone could explain these changes. We suggest that the qualitative change (i.e. learning of a new task) is more critical for the brain to change its structure than continued training of an already-learned task.

Genetic Variation and De Novo Mutations in the Parthenogenetic Caucasian Rock Lizard Darevskia unisexualis:

Unisexual all-female lizards of the genus Darevskia that are well adapted to various habitats are known to reproduce normally by true parthenogenesis. Although they consist of unisexual lineages and lack effective genetic recombination, they are characterized by some level of genetic polymorphism. To reveal the mutational contribution to overall genetic variability, the most straightforward and conclusive way is the direct detection of mutation events in pedigree genotyping. Earlier we selected from genomic library of D. unisexualis two polymorphic microsatellite containg loci Du281 and Du215. In this study, these two loci were analyzed to detect possible de novo mutations in 168 parthenogenetic offspring of 49 D. unisexualis mothers and in 147 offspring of 50 D. armeniaca mothers . No mutant alleles were detected in D. armeniaca offspring at both loci, and in D. unisexualis offspring at the Du215 locus. There were a total of seven mutational events in the germ lines of four of the 49 D. unisexualis mothers at the Du281 locus, yielding the mutation rate of 0.1428 events per germ line tissue. Sequencing of the mutant alleles has shown that most mutations occur via deletion or insertion of single microsatellite repeat being identical in all offspring of the family. This indicates that such mutations emerge at the early stages of embryogenesis. In this study we characterized single highly unstable (GATA)n containing locus in parthenogenetic lizard species D. unisexualis. Besides, we characterized various types of mutant alleles of this locus found in the D. unisexualis offspring of the first generation. Our data has shown that microsatellite mutations at highly unstable loci can make a significant contribution to population variability of parthenogenetic lizards.

Universal Scaling in the Branching of the Tree of Life:

Understanding the patterns and processes of diversification of life in the planet is a key challenge of science. The Tree of Life represents such diversification processes through the evolutionary relationships among the different taxa, and can be extended down to intra-specific relationships. Here we examine the topological properties of a large set of interspecific and intraspecific phylogenies and show that the branching patterns follow allometric rules conserved across the different levels in the Tree of Life, all significantly departing from those expected from the standard null models. The finding of non-random universal patterns of phylogenetic differentiation suggests that similar evolutionary forces drive diversification across the broad range of scales, from macro-evolutionary to micro-evolutionary processes, shaping the diversity of life on the planet.

The Male Sex Pheromone of the Butterfly Bicyclus anynana: Towards an Evolutionary Analysis:

Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies. Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP. This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.

Neutrality and the Response of Rare Species to Environmental Variance:

Neutral models and differential responses of species to environmental heterogeneity offer complementary explanations of species abundance distribution and dynamics. Under what circumstances one model prevails over the other is still a matter of debate. We show that the decay of similarity over time in rocky seashore assemblages of algae and invertebrates sampled over a period of 16 years was consistent with the predictions of a stochastic model of ecological drift at time scales larger than 2 years, but not at time scales between 3 and 24 months when similarity was quantified with an index that reflected changes in abundance of rare species. A field experiment was performed to examine whether assemblages responded neutrally or non-neutrally to changes in temporal variance of disturbance. The experimental results did not reject neutrality, but identified a positive effect of intermediate levels of environmental heterogeneity on the abundance of rare species. This effect translated into a marked decrease in the characteristic time scale of species turnover, highlighting the role of rare species in driving assemblage dynamics in fluctuating environments.

Cheating on the Edge:

We present the results of an individual agent-based model of antibiotic resistance in bacteria. Our model examines antibiotic resistance when two strategies exist: “producers”-who secrete a substance that breaks down antibiotics-and nonproducers (“cheats”) who do not secrete, or carry the machinery associated with secretion. The model allows for populations of up to 10,000, in which bacteria are affected by their nearest neighbors, and we assume cheaters die when there are no producers in their neighborhood. Each of 10,000 slots on our grid (a torus) could be occupied by a producer or a nonproducer, or could (temporarily) be unoccupied. The most surprising and dramatic result we uncovered is that when producers and nonproducers coexist at equilibrium, nonproducers are almost always found on the edges of clusters of producers.

Network Evolution of Body Plans:

One of the major goals in evolutionary developmental biology is to understand the relationship between gene regulatory networks and the diverse morphologies and their functionalities. Are the diversities solely triggered by random events, or are they inevitable outcomes of an interplay between evolving gene networks and natural selection? Segmentation in arthropod embryogenesis represents a well-known example of body plan diversity. Striped patterns of gene expression that lead to the future body segments appear simultaneously or sequentially in long and short germ-band development, respectively. Moreover, a combination of both is found in intermediate germ-band development. Regulatory genes relevant for stripe formation are evolutionarily conserved among arthropods, therefore the differences in the observed traits are thought to have originated from how the genes are wired. To reveal the basic differences in the network structure, we have numerically evolved hundreds of gene regulatory networks that produce striped patterns of gene expression. By analyzing the topologies of the generated networks, we show that the characteristics of stripe formation in long and short germ-band development are determined by Feed-Forward Loops (FFLs) and negative Feed-Back Loops (FBLs) respectively, and those of intermediate germ-band development are determined by the interconnections between FFL and negative FBL. Network architectures, gene expression patterns and knockout responses exhibited by the artificially evolved networks agree with those reported in the fly Drosophila melanogaster and the beetle Tribolium castaneum. For other arthropod species, principal network architectures that remain largely unknown are predicted. Our results suggest that the emergence of the three modes of body segmentation in arthropods is an inherent property of the evolving networks.

Does Pathogen Spillover from Commercially Reared Bumble Bees Threaten Wild Pollinators?:

The conservation of insect pollinators is drawing attention because of reported declines in bee species and the ‘ecosystem services’ they provide. This issue has been brought to a head by recent devastating losses of honey bees throughout North America (so called, ‘Colony Collapse Disorder’); yet, we still have little understanding of the cause(s) of bee declines. Wild bumble bees (Bombus spp.) have also suffered serious declines and circumstantial evidence suggests that pathogen ‘spillover’ from commercially reared bumble bees, which are used extensively to pollinate greenhouse crops, is a possible cause. We constructed a spatially explicit model of pathogen spillover in bumble bees and, using laboratory experiments and the literature, estimated parameter values for the spillover of Crithidia bombi, a destructive pathogen commonly found in commercial Bombus. We also monitored wild bumble bee populations near greenhouses for evidence of pathogen spillover, and compared the fit of our model to patterns of C. bombi infection observed in the field. Our model predicts that, during the first three months of spillover, transmission from commercial hives would infect up to 20% of wild bumble bees within 2 km of the greenhouse. However, a travelling wave of disease is predicted to form suddenly, infecting up to 35-100% of wild Bombus, and spread away from the greenhouse at a rate of 2 km/wk. In the field, although we did not observe a large epizootic wave of infection, the prevalences of C. bombi near greenhouses were consistent with our model. Indeed, we found that spillover has allowed C. bombi to invade several wild bumble bee species near greenhouses. Given the available evidence, it is likely that pathogen spillover from commercial bees is contributing to the ongoing decline of wild Bombus in North America. Improved management of domestic bees, for example by reducing their parasite loads and their overlap with wild congeners, could diminish or even eliminate pathogen spillover.

Commercial Bees Spreading Disease To Wild Pollinating Bees:

Bees provide crucial pollination service to numerous crops and up to a third of the human diet comes from plants pollinated by insects. However, pollinating bees are suffering widespread declines in North America and scientists warn that this could have serious implications for agriculture and food supply. While the cause of these declines has largely been a mystery, new research reveals an alarming spread of disease from commercial bees to wild pollinators.

Unique Fossil Discovery Shows Antarctic Was Once Much Warmer:

A new fossil discovery- the first of its kind from the whole of the Antarctic continent- provides scientists with new evidence to support the theory that the polar region was once much warmer.

New Population Of Highly Threatened Greater Bamboo Lemur Found In Madagascar:

Researchers in Madagascar have confirmed the existence of a population of greater bamboo lemurs more than 400 kilometers (240 miles) from the only other place where the Critically Endangered species is known to live, raising hopes for its survival.

Some Earthworms Make Septic Systems Work Better, Others Do The Opposite:

The right earthworms can make home septic systems work better. The wrong ones could do the opposite.

Hormone Oxytocin May Inhibit Social Phobia:

Swedish and British scientists have shown using functional magnetic resonance imaging (fMRI) that the hormone oxytocin can inhibit feelings of anxiety in specific individuals. Their discovery might lead to a better understanding and the improved treatment of psychiatric affections in which people feel distressed when meeting others, such as in cases of autism and social phobia.

Pollination Habits Of Endangered Texas Rice Revealed To Help Preservation:

A type of wild rice that only grows in a small stretch of the San Marcos River is likely so rare because it plays the sexual reproduction game poorly, a study led by the Lady Bird Johnson Wildflower Center at The University of Texas at Austin has revealed.

Genetics Of White Horses Unraveled: One Mutation Makes Ordinary Horses Turn Grey, Then White, Very Young:

The white horse is an icon for dignity which has had a huge impact on human culture across the world. An international team led by researchers at Uppsala University has now identified the mutation causing this spectacular trait and show that white horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago.

Environmental Factors Linked To Sex Ratio Of Plants Discovered:

Environmental factors can transform the ratio of females to males in plant populations according to new research out of the University of Toronto.

90 Billion Tons Of Microbial Organisms Live In Deep Marine Subsurface: More Archaea Than Bacteria:

Biogeoscientists show evidence of 90 billion tons of microbial organisms–expressed in terms of carbon mass–living in the deep biosphere, in a research article published online by Nature, July 20, 2008. This tonnage corresponds to about one-tenth of the amount of carbon stored globally in tropical rainforests.

Female Monkeys More Dominant In Groups With Relatively More Males:

Female monkeys are more dominant when they live in groups with a higher percentage of males. This is caused by self-organisation. This surprising discovery was made by researchers at the University of Groningen. What makes the study particularly interesting is that the researchers used a computer model which can simulate interaction between monkeys.

For Your Eyes Only: Custom Interfaces Make Computer Clicking Faster, Easier:

Insert your key in the ignition of a luxury car and the seat and steering wheel will automatically adjust to preprogrammed body proportions. Stroll through the rooms of Bill Gates’ mansion and each room will adjust its lighting, temperature and music to accommodate your personal preference. But open any computer program and you’re largely subject to a design team’s ideas about button sizes, fonts and layouts.

Pregnant Mice Block Odor Of Strange Male’s Urine To Protect Their Pups:

Mouse mothers-to-be have a remarkable way to protect their unborn pups. Because the smell of a strange male’s urine can cause miscarriage and reactivate the ovulatory cycle, pregnant mice prevent the action of such olfactory stimuli by blocking their smell. Researchers from the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, have now revealed the nature of this ability. A surge of the chemical signal dopamine in the main olfactory bulb – one of the key brain areas for olfactory perception — creates a barrier for male odours, they report in the current issue of Nature Neuroscience.

Suckling Infants Trigger Surges Of Trust Hormone In Mothers’ Brains:

Researchers from the University of Warwick, in collaboration with other universities and institutes in Edinburgh, France and Italy, have for the first time been able to show exactly how, when a baby suckles at a mother’s breast, it starts a chain of events that leads to surges of the “trust” hormone oxytocin being released in their mothers brains.

Common Wisdom About Troubled Youth Falls Apart When Race Considered:

One of the most widely accepted beliefs about the differences between troubled boys and girls may need to be revised, according to new research. Experts have long believed that girls tend to internalize their problems, becoming depressed or anxious, while boys externalize, turning to violence against people or property.

Ultrasonic Frogs Can Tune Their Ears To Different Frequencies:

Researchers have discovered that a frog that lives near noisy springs in central China can tune its ears to different sound frequencies, much like the tuner on a radio can shift from one frequency to another. It is the only known example of an animal that can actively select what frequencies it hears, the researchers say.

Across the Curious Parallel of Language and Species Evolution:

In February 1837–even before he sailed on the Beagle–Charles Darwin wrote to his sister Caroline, discussing the linguist Sir John Herschel’s idea that modern languages were descended from a common ancestor. If this were really the case, it cast doubt on the Biblical chronology of the world: “[E]veryone has yet thought that the six thousand odd years has been the right period but Sir J. thinks that a far greater number must have passed since the Chinese [and] the Caucasian languages separated from one stock”.

The Effects of International Monetary Fund Loans on Health Outcomes:

What kind of impact might IMF loans, and their conditionalities, have upon health outcomes? A new study in this issue of PLoS Medicine attempts to address this question by examining IMF programs and tuberculosis (TB) outcomes in post-communist countries [1].
Critics of the IMF charge that IMF conditionalities have helped undermine the health of some of the world’s most vulnerable populations. They argue that health outcomes suffer from reduced government spending on health care and on other inputs to health, such as food, as well as from the capping of public sector wages. IMF policies are also cited as having led to the diversion of foreign aid intended for health to the repayment of domestic debt. Such an outcome could serve as a strong disincentive for external funders to increase future health financing.

WikiPathways: Pathway Editing for the People:

The exponential growth of diverse types of biological data presents the research community with an unprecedented challenge and opportunity. The challenge is to stay afloat in the flood of biological data, keeping it as accessible, up-to-date, and integrated as possible. The opportunity is to cultivate new models of data curation and exchange that take advantage of direct participation by a greater portion of the community.
This combination of challenge and opportunity is especially relevant to the task of collecting biological pathway information. Pathways are critical to understanding the functions of individual genes and proteins in terms of systems and processes that contribute to normal physiology and to disease. Each biological pathway must be hewn from a mass of biological information distributed across multiple publications and databases.

Visuomotor Transformation in the Fly Gaze Stabilization System:

Many behavioral tasks rely on sensory information. This information, however, needs to be transformed into a format that is compatible with the requirements of motor systems. In this study we characterize the neural basis of such a sensorimotor transformation in a model system. Flies, like humans, stabilize their gaze to keep their eyes level, even when the body is rotating. An identified population of fly brain neurons called lobula plate tangential cells (LPTCs) contributes to this task. These cells analyze the wide-field retinal image shifts generated when the fly is moving relative to its environment. We have characterized the visual receptive fields of motor neurons that use the information encoded by LPTCs to control gaze-stabilizing head movements. Our results suggest that the motor neurons use their LPTC inputs in a comparatively simple and direct way: they combine inputs from both sides of the brain to increase the motor neurons’ selectivity for rotations. Such a mechanism enables a specific, fast, and surprisingly simple sensorimotor transformation in which visual information contributes to gaze stabilization.

Social Behavior In Ants Influenced By Small Number Of Genes:

Understanding how interactions between genes and the environment influence social behavior is a fundamental research goal. In a new study, researchers at the University of Lausanne and the University of Georgia have shed light on the numbers and types of genes that may control social organization in fire ant colonies.

Regular Walking Protects The Masai — Who Eat High Fat Diet — From Cardiovascular Disease:

Scientists have long been puzzled by how the Masai can avoid cardiovascular disease despite having a diet rich in animal fats. Researchers at Karolinska Institutet believe that their secret is in their regular walking.

Dust Storms In Sahara Desert Sustain Life In Atlantic Ocean:

Research at the University of Liverpool has found how Saharan dust storms help sustain life over extensive regions of the North Atlantic Ocean.

Changes In Winds Could Have Been Cause Of Abrupt Glacial Climatic Change:

Spanish and German researchers have carried out a collaborative study that shows how during the last glacial period, small variations in the surface winds could have induced significant changes in the oceanic currents of the North Atlantic, and could even have played a role in the abrupt climate change that occurred at the time.

Spotted Hyenas Can Increase Survival Rates By Hunting Alone:

Recent research by Michigan State University doctoral student Jennifer Smith has shed new light on the way spotted hyenas live together and – more importantly – hunt for their food alone.

How A Simple Mathematic Formula Is Starting To Explain The Bizarre Prevalence Of Altruism In Society:

Why do humans cooperate in things as diverse as environment conservation or the creation of fairer societies, even when they don’t receive anything in exchange or, worst, they might even be penalized? This is a question that has puzzled academics for centuries, especially since in evolution the basis for the “survival of the fittest” is, after all, selfishness.

Loud Music Can Make You Drink More, In Less Time, In A Bar:

Commercial venues are very aware of the effects that the environment — in this case, music — can have on in-store traffic flow, sales volumes, product choices, and consumer time spent in the immediate vicinity. A study of the effects of music levels on drinking in a bar setting has found that loud music leads to more drinking in less time.

Horse Racecourse In Ancient Olympia Discovered After 1600 Years:

The site of the ancient hippodrome course in Olympia, where the emperor Nero competed for Olympian laurels, has been discovered. The hippodrome was discovered in Olympia by a research team that included Professor Norbert Müller (a sports historian from Mainz), Dr Christian Wacker (a sports archaeologist from Cologne) and PD Dr Reinhard Senff (chief excavator of the German Archaeological Institute – DAI.

Second Life Improves Real-life Social Skills:

Social interaction is enhanced rather than diminished by online interfaces, according to new research on the virtual program Second Life. Eryn Grant, a PhD student in Queensland University of Technology’s School of Humanities, recently completed a study which took an in-depth look at social order in emergent online environments.

Semantics Gives The Web Meaning – For Machines:

Where would we be without the web? It is such an immense and rich source of information; we feel that every answer is out there. All it takes is a bit of searching…

Lionfish Decimating Tropical Fish Populations, Threatening Coral Reefs:

The invasion of predatory lionfish in the Caribbean region poses yet another major threat there to coral reef ecosystems — a new study has found that within a short period after the entry of lionfish into an area, the survival of other reef fishes is slashed by about 80 percent.

If Northern Trees Suffer Because Of Global Warming, Southern Trees May Still Be Slow To Replace Them:

If a warmer Wisconsin climate causes some northern tree species to disappear in the future, it’s easy to imagine that southern species will just expand their range northward as soon as the conditions suit them.

How Birds Spot The Cuckoo In The Nest:

It’s not always easy spotting the cuckoo in the nest. But if you don’t, you pay a high price raising someone else’s chick. How hosts distinguish impostor eggs from their own has long puzzled scientists. The problem remained largely unsolved while looking at it through our own eyes. It was only when people started thinking from the birds’ perspective that they began to understand how hosts recognise a cuckoo egg in the nest.

Natural Selection May Not Produce The Best Organisms:

“Survival of the fittest” is the catch phrase of evolution by natural selection. While natural selection favors the most fit organisms around, evolutionary biologists have long wondered whether this leads to the best possible organisms in the long run.

Distribution Of Creatures Great And Small Can Be Predicted Mathematically:

In studying how animals change size as they evolve, biologists have unearthed several interesting patterns. For instance, most species are small, but the largest members of a taxonomic group — such as the great white shark, the Komodo dragon, or the African elephant — are often thousands or millions of times bigger than the typical species. Now for the first time two SFI researchers explain these patterns within an elegant statistical framework.

Bees Go ‘Off-color’ When They Are Sickly:

Bumble-bees go ‘off colour’ and can’t remember which flowers have the most nectar when they are feeling under the weather, a new study from the University of Leicester reveals.

Tips On How To Build A Better Home For Biological Parts:

Researchers at the Virginia Bioinformatics Institute (VBI) at Virginia Tech have compiled a series of guidelines that should help researchers in their efforts to design, develop and manage next-generation databases of biological parts. The stakes are high: the concept of biological parts is essential if methods developed in other fields of engineering are to be applied to biology. If successful, this approach will result in significant productivity gains for the biotechnology industry.

New Model Explains Why We Overestimate Our Future Choices:

When people make choices for future consumption, they select a wider variety than when they plan to immediately consume the products. A new study examines the reasons behind this diversification of choices.

Paradoxical Relationship Discovered Between Dengue Hemorrhagic Fever And Its Carrier Mosquitoes:

A study by researchers in Thailand, Japan, and the UK has shown a negative correlation between dengue hemorrhagic fever (DHF) and the density of the Aedes mosquitoes that transmit the virus. The study explains how current efforts to reduce the mosquitoes may actually increase the incidence of the potentially fatal viral disease.

Leatherback Turtles’ Newly Discovered Migration Route May Be Roadmap To Salvation:

With a name like “Leatherback Turtle” you might think the sea turtles could stand up to just about anything the ocean can throw at them, and for more than a hundred million years, they have. But tough, long-lived critters though they are, the population of leatherbacks in the eastern Pacific Ocean has plummeted by over 90 percent in the last 20 years.

Pathologists Believe They Have Pinpointed Achilles Heel Of HIV:

Human Immunodeficiency Virus (HIV) researchers at The University of Texas Medical School at Houston believe they have uncovered the Achilles heel in the armor of the virus that continues to kill millions.

Farming At Young Age May Lead To Bone Disease In Adulthood:

Although farm chores are likely to keep young boys in shape and out of trouble, University of Cincinnati (UC) environmental health experts caution that it could be harmful to overall bone health if done too often at a young age.

Volcanic Eruptions May Have Wiped Out Ocean Life 94 Million Years Ago:

Undersea volcanic activity triggered a mass extinction of marine life and buried a thick mat of organic matter on the sea floor about 93 million years ago, which became a major source of oil, according to a new study.

Distribution Of A Species Of Butterfly Predicted Using Geometric Variables:

Biologists have recently explored the distribution of the butterfly Iolana iolas, one of the endangered species in the Madrid region whose population dynamics are determined by its host plant. The study, prepared by scientists from the King Juan Carlos University in Madrid, proposes a new path for designing conservation plans for the species using geometric variables.

Good News For Veggies: Personal Values Deceive Taste Buds:

Many heavy meat eaters believe they eat a lot of meat because of the taste. But according to groundbreaking new research the reason that a beef burger tastes better than a veggie burger to some people has more to do with values than actual taste.