Category Archives: Science News

Tiny Cellular Antennae Trigger Neural Stem Cells:

Yale University scientists today reported evidence suggesting that the tiny cilia found on brain cells of mammals, thought to be vestiges of a primeval past, actually play a critical role in relaying molecular signals that spur creation of neurons in an area of the brain involved in mood, learning and memory.

Picking Out Specific Sounds In A Complex Scene: Researchers Study ‘Cocktail Party Effect’, Measure Auditory Dynamics Of Selective Attention:

Call it the cocktail party effect: how an individual can participate in a one-on-one conversation within a cluster of people, switch to another, pick up important comments while tuning out others, change topics and return to the first conversation.

Starting Kindergarten Later Gives Students Only A Fleeting Edge, Study Finds:

New research challenges a growing trend toward holding kids out of kindergarten until they’re older, arguing that academic advantages are short-lived and come at the expense of delaying entry into the workforce and other costs.

Part Of The In-group? A Surprising New Strategy Helps Reduce Unhealthy Behaviors:

Public health campaigns intended to reduce unhealthy behaviors like binge drinking and eating junk food often focus on the risks of those behaviors. But a new study in the Journal of Consumer Research suggests a relatively simple but surprisingly effective strategy to improve consumer health.

79 Million US Adults Have Medical Bill Problems Or Are Paying Off Medical Debt:

The proportion of working-age Americans who have medical bill problems or who are paying off medical debt climbed from 34 percent to 41 percent between 2005 and 2007, bringing the total to 72 million, according to recent survey findings from The Commonwealth Fund. In addition, 7 million adults age 65 and over also had problems paying medical bills, for a total of 79 million adults with medical bill problems or medical debt.

Foul Owls Use Feces To Show They Are In Fine Feather:

Some years ago, within the Department of Conservation Biology of the Estación Biológica de Doñana (EBD-Consejo Superior de Investigaciones Científicas; Seville, Spain), a recently established group (colloquially named the Night Ecology Group) started to explore the possibility of visual communication in crepuscular and nocturnal birds.

Exploding Chromosomes Fuel Research About Evolution Of Genetic Storage:

Human cells somehow squeeze two meters of double-stranded DNA into the space of a typical chromosome, a package 10,000 times smaller than the volume of genetic material it contains.

Fish Cancer Gene Linked To Pigment Pattern That Attracts Mates:

Though skin cancer is deadly to male fish, it also has one perk: The black melanoma splotches arise from attractive natural markings that lure female mates. A new study published in the Proceedings of the National Academy of Sciences this week shows that the melanoma gene can be conserved in swordtail fish because of its beneficial role in sexual selection.

Addiction Treatment Proves Successful In Animal Weight Loss Study:

Vigabatrin, a medication proposed as a potential treatment for drug addiction by scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, also leads to rapid weight loss and reduced food intake according to a new animal study from the same research group.

Insomnia: Changing Your Bedtime Habits Could Help:

Many people sleep better when they are on holiday and wish that they could sleep as well all the time. But according to the German Institute for Quality and Efficiency in Health Care (IQWiG), it is not only being free of daily worries that can make a difference to sleep. Good bedtime habits can help people to sleep well all year round. Medication provides short-term relief at best.

Snacks In Small Packages May Lead To Overeating:

Tempting treats are being offered in small package sizes these days, presumably to help consumers reduce portion sizes. Yet new research found that people actually consume more high-calorie snacks when they are in small packages than large ones. And smaller packages make people more likely to give in to temptation in the first place.

With Skate Eyes, Scientists Peer Into Human Disease:

Paradoxically, the photoreceptor cells in our retinas release more of their neurotransmitter, glutamate, in the dark, when there is nothing to see, than they do in the light. This is doubly surprising since although glutamate is a major signaling molecule in the retina and throughout the central nervous system, it is also a potent cytotoxin that, in large doses, can kill nearby cells.

New Algorithm Significantly Boosts Routing Efficiency Of Networks:

A time-and-money-saving question shared by commuters in their cars and networks sharing ever-changing Internet resources is: “What’s the best way to get from here to there?”

New And Improved Test For West Nile Virus In Horses:

A new test for West Nile virus in horses that could be modified for use on humans and wildlife may help track the spread of the disease, according to an article in the September issue of the Journal of Medical Microbiology.

Insomnia: Changing Your Bedtime Habits Could Help:

Many people sleep better when they are on holiday and wish that they could sleep as well all the time. But according to the German Institute for Quality and Efficiency in Health Care (IQWiG), it is not only being free of daily worries that can make a difference to sleep. Good bedtime habits can help people to sleep well all year round. Medication provides short-term relief at best.

Hormone Replacement Therapy Improves Sleep, Sexuality And Joint Pain In Older Women:

One of the world’s longest and largest trials of hormone replacement therapy (HRT) has found that post-menopausal women on HRT gain significant improvements in quality of life.

Is It Possible To Teach Experience? European Researchers Say Yes:

Business veterans claim you cannot teach ‘experience’, but European researchers say you can. The team developed software that helps players acquire real-life skills and realistic experiences through game playing. But this game is no executive toy.

Genome Of Simplest Animal Reveals Ancient Lineage, Confounding Array Of Complex Capabilities:

As Aesop said, appearances are deceiving–even in life’s tiniest critters. From first detection in the 1880s, clinging to the sides of an aquarium, to its recent characterization by the U.S. Department of Energy Joint Genome Institute (DOE JGI), a simple and primitive animal, Trichoplax adhaerens, appears to harbor a far more complex suite of capabilities than meets the eye.

Genes And Nutrition Influence Caste In Unusual Species Of Harvester Ant:

Researchers trying to determine whether nature or nurture determines an ant’s status in the colony have found a surprising answer. Both.

There are 7 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:

Continue reading →

Face Recognition: Nurture Not Nature:

Researchers have discovered that our society can influence the way we recognise other people’s faces. Because face recognition is effortlessly achieved by people from all different cultures it was considered to be a basic mechanism universal among humans. However, by using analyses inspired by novel brain imaging technology, researchers at the University of Glasgow have discovered that cultural differences cause us to look at faces differently.

Manes, Trains And Antlers Explained: How Showy Male Traits Evolved:

For Charles Darwin, the problem of the peacock’s tail, in light of his theory of natural selection, was vexing in the extreme. Indeed, in 1860, writing to Asa Gray, his most ardent American champion, Darwin confessed: “The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick!” In his struggle to explain why such extravagant and seemingly burdensome features existed, the great English naturalist struck upon the idea of sexual selection — that showy traits such as the Peacock’s ornamentation were an advantage in the mating game that outweighed other disadvantages.

Shipwrecks On Coral Reefs Harbor Unwanted Species:

Shipwrecks on coral reefs may increase invasion of unwanted species, according to a recent U.S. Geological Survey study. These unwanted species can completely overtake the reef and eliminate all the native coral, dramatically decreasing the diversity of marine organisms on the reef. This study documents for the first time that a rapid change in the dominant biota on a coral reef is unambiguously associated with man-made structures.

Genetics Reveals Big Fish That Almost Got Away:

Researchers from the University of Hawaii, the Wildlife Conservation Society, Smithsonian Tropical Research Institute, National Marine Fisheries Service and Projecto Meros do Brazil discovered a new species of fish–a grouper that reaches more than six feet in length and can weigh nearly 1,000 pounds. This newly discovered species can be found roaming the tropical reefs of the Eastern Pacific Ocean.

Kids With Pets Grow Up To Be Snorers:

A predisposition to adult snoring can be established very early in life. New research describes possible childhood risk factors, including exposure to animals, early respiratory or ear infections and growing up in a large family.

Research Shows Pollsters How The Undecided Will Vote:

As the American Presidential election approaches, pollsters are scrambling to predict who will win. A study by a team of researchers at The University of Western Ontario, Canada, and the University of Padova, Italy, may give pollsters a new way to determine how the undecided will vote, even before the voters know themselves.

Trees Kill Odors And Other Emissions From Poultry Farms:

Planting just three rows of trees around poultry farms can cut nuisance emissions of dust, ammonia, and odors from poultry houses and aid in reducing neighbor complaints, according to scientists from the University of Delaware.

Dietary Supplements For Horses, Dogs And Cats Need Better Regulation, New Report Says:

The growing use of animal dietary supplements has raised several concerns, including the safety of specific supplements and the approaches taken to determine their safeness.

There are 10 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:
A Dominant X-Linked QTL Regulating Pubertal Timing in Mice Found by Whole Genome Scanning and Modified Interval-Specific Congenic Strain Analysis:

Pubertal timing in mammals is triggered by reactivation of the hypothalamic-pituitary-gonadal (HPG) axis and modulated by both genetic and environmental factors. Strain-dependent differences in vaginal opening among inbred mouse strains suggest that genetic background contribute significantly to the puberty timing, although the exact mechanism remains unknown. We performed a genome-wide scanning for linkage in reciprocal crosses between two strains, C3H/HeJ (C3H) and C57BL6/J (B6), which differed significantly in the pubertal timing. Vaginal opening (VO) was used to characterize pubertal timing in female mice, and the age at VO of all female mice (two parental strains, F1 and F2 progeny) was recorded. A genome-wide search was performed in 260 phenotypically extreme F2 mice out of 464 female progeny of the F1 intercrosses to identify quantitative trait loci (QTLs) controlling this trait. A QTL significantly associated was mapped to the DXMit166 marker (15.5 cM, LOD = 3.86, p<0.01) in the reciprocal cross population (C3HB6F2). This QTL contributed 2.1 days to the timing of VO, which accounted for 32.31% of the difference between the original strains. Further study showed that the QTL was B6-dominant and explained 10.5% of variation to this trait with a power of 99.4% at an alpha level of 0.05.The location of the significant ChrX QTL found by genome scanning was then fine-mapped to a region of ~2.5 cM between marker DXMit68 and rs29053133 by generating and phenotyping a panel of 10 modified interval-specific congenic strains (mISCSs). Such findings in our study lay a foundation for positional cloning of genes regulating the timing of puberty, and also reveal the fact that chromosome X (the sex chromosome) does carry gene(s) which take part in the regulative pathway of the pubertal timing in mice.

Elusive Origins of the Extra Genes in Aspergillus oryzae:

The genome sequence of Aspergillus oryzae revealed unexpectedly that this species has approximately 20% more genes than its congeneric species A. nidulans and A. fumigatus. Where did these extra genes come from? Here, we evaluate several possible causes of the elevated gene number. Many gene families are expanded in A. oryzae relative to A. nidulans and A. fumigatus, but we find no evidence of ancient whole-genome duplication or other segmental duplications, either in A. oryzae or in the common ancestor of the genus Aspergillus. We show that the presence of divergent pairs of paralogs is a feature peculiar to A. oryzae and is not shared with A. nidulans or A. fumigatus. In phylogenetic trees that include paralog pairs from A. oryzae, we frequently find that one of the genes in a pair from A. oryzae has the expected orthologous relationship with A. nidulans, A. fumigatus and other species in the subphylum Eurotiomycetes, whereas the other A. oryzae gene falls outside this clade but still within the Ascomycota. We identified 456 such gene pairs in A. oryzae. Further phylogenetic analysis did not however indicate a single consistent evolutionary origin for the divergent members of these pairs. Approximately one-third of them showed phylogenies that are suggestive of horizontal gene transfer (HGT) from Sordariomycete species, and these genes are closer together in the A. oryzae genome than expected by chance, but no unique Sordariomycete donor species was identifiable. The postulated HGTs from Sordariomycetes still leave the majority of extra A. oryzae genes unaccounted for. One possible explanation for our observations is that A. oryzae might have been the recipient of many separate HGT events from diverse donors.

Progesterone from the Cumulus Cells Is the Sperm Chemoattractant Secreted by the Rabbit Oocyte Cumulus Complex:

Sperm chemotaxis in mammals have been identified towards several female sources as follicular fluid (FF), oviduct fluid, and conditioned medium from the cumulus oophorus (CU) and the oocyte (O). Though several substances were confirmed as sperm chemoattractant, Progesterone (P) seems to be the best chemoattractant candidate, because: 1) spermatozoa express a cell surface P receptor, 2) capacitated spermatozoa are chemotactically attracted in vitro by gradients of low quantities of P; 3) the CU cells produce and secrete P after ovulation; 4) a gradient of P may be kept stable along the CU; and 5) the most probable site for sperm chemotaxis in vivo could be near and/or inside the CU. The aim of this study was to verify whether P is the sperm chemoattractant secreted by the rabbit oocyte-cumulus complex (OCC) in the rabbit, as a mammalian animal model. By means of videomicroscopy and computer image analysis we observed that only the CU are a stable source of sperm attractants. The CU produce and secrete P since the hormone was localized inside these cells by immunocytochemistry and in the conditioned medium by enzyme immunoassay. In addition, rabbit spermatozoa express a cell surface P receptor detected by western blot and localized over the acrosomal region by immunocytochemistry. To confirm that P is the sperm chemoattractant secreted by the CU, the sperm chemotactic response towards the OCC conditioned medium was inhibited by three different approaches: P from the OCC conditioned medium was removed with an anti-P antibody, the attractant gradient of the OCC conditioned medium was disrupted by a P counter gradient, and the sperm P receptor was blocked with a specific antibody. We concluded that only the CU but not the oocyte secretes P, and the latter chemoattract spermatozoa by means of a cell surface receptor. Our findings may be of interest in assisted reproduction procedures in humans, animals of economic importance and endangered species.

Reverse and Conventional Chemical Ecology Approaches for the Development of Oviposition Attractants for Culex Mosquitoes:

Synthetic mosquito oviposition attractants are sorely needed for surveillance and control programs for Culex species, which are major vectors of pathogens causing various human diseases, including filariasis, encephalitis, and West Nile encephalomyelitis. We employed novel and conventional chemical ecology approaches to identify potential attractants, which were demonstrated in field tests to be effective for monitoring populations of Cx. p. quinquefasciatus in human dwellings. Immunohistochemistry studies showed that an odorant-binding protein from this species, CquiOBP1, is expressed in trichoid sensilla on the antennae, including short, sharp-tipped trichoid sensilla type, which house an olfactory receptor neuron sensitive to a previously identified mosquito oviposition pheromone (MOP), 6-acetoxy-5-hexadecanolide. CquiOBP1 exists in monomeric and dimeric forms. Monomeric CquiOBP1 bound MOP in a pH-dependent manner, with a change in secondary structure apparently related to the loss of binding at low pH. The pheromone antipode showed higher affinity than the natural stereoisomer. By using both CquiOBP1 as a molecular target in binding assays and gas chromatography-electroantennographic detection (GC-EAD), we identified nonanal, trimethylamine (TMA), and skatole as test compounds. Extensive field evaluations in Recife, Brazil, a region with high populations of Cx. p. quinquefasciatus, showed that a combination of TMA (0.9 µg/l) and nonanal (0.15 ng/µl) is equivalent in attraction to the currently used infusion-based lure, and superior in that the offensive smell of infusions was eliminated in the newly developed synthetic mixture.

Prefrontal Norepinephrine Determines Attribution of “High” Motivational Salience:

Intense motivational salience attribution is considered to have a major role in the development of different psychopathologies. Numerous brain areas are involved in “normal” motivational salience attribution processes; however, it is not clear whether common or different neural mechanisms also underlie intense motivational salience attribution. To elucidate this a brain area and a neural system had to be envisaged that were involved only in motivational salience attribution to highly salient stimuli. Using intracerebral microdialysis, we found that natural stimuli induced an increase in norepinephrine release in the medial prefrontal cortex of mice proportional to their salience, and that selective prefrontal norepinephrine depletion abolished the increase of norepinephrine release in the medial prefrontal cortex induced by exposure to appetitive (palatable food) or aversive (light) stimuli independently of salience. However, selective norepinephrine depletion in the medial prefrontal cortex impaired the place conditioning induced exclusively by highly salient stimuli, thus indicating that prefrontal noradrenergic transmission determines approach or avoidance responses to both reward- and aversion-related natural stimuli only when the salience of the unconditioned natural stimulus is high enough to induce sustained norepinephrine outflow. This affirms that prefrontal noradrenergic transmission determines motivational salience attribution selectively when intense motivational salience is processed, as in conditions that characterize psychopathological outcomes.

Tailor-made Functional Garments For Olympic Horses:

When the horses and competitors go through their paces at the Summer Olympics in Hong Kong in 2008, it will be very hot and very humid – just as it is every summer there. Three special blankets will offer the Swiss teams’ tournament horses some respite from the elements.

Tracing Origins Of Critical Step In Animal Evolution — The Development Of Nerves:

University of Queensland researchers have traced the origins of one of the most important steps in animal evolution – the development of nerves.

Future Impact Of Global Warming Is Worse When Grazing Animals Are Considered, Scientists Suggest:

The impact of global warming in the Arctic may differ from the predictions of computer models of the region, according to a pair of Penn State biologists. The team — which includes Eric Post, a Penn State associate professor of biology, and Christian Pederson, a Penn State graduate student — has shown that grazing animals will play a key role in reducing the anticipated expansion of shrub growth in the region, thus limiting their predicted and beneficial carbon-absorbing effect.

One Sleepless Night Increases Dopamine In The Human Brain:

ust one night without sleep can increase the amount of the chemical dopamine in the human brain, according to new imaging research in the August 20 issue of The Journal of Neuroscience. Because drugs that increase dopamine, like amphetamines, promote wakefulness, the findings offer a potential mechanism explaining how the brain helps people stay awake despite the urge to sleep.

There are 12 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:
Seeing without Seeing? Degraded Conscious Vision in a Blindsight Patient:

Blindsight patients, whose primary visual cortex is lesioned, exhibit preserved ability to discriminate visual stimuli presented in their “blind” field, yet report no visual awareness hereof. Blindsight is generally studied in experimental investigations of single patients, as very few patients have been given this “diagnosis”. In our single case study of patient GR, we ask whether blindsight is best described as unconscious vision, or rather as conscious, yet severely degraded vision. In experiment 1 and 2, we successfully replicate the typical findings of previous studies on blindsight. The third experiment, however, suggests that GR’s ability to discriminate amongst visual stimuli does not reflect unconscious vision, but rather degraded, yet conscious vision. As our finding results from using a method for obtaining subjective reports that has not previously used in blindsight studies (but validated in studies of healthy subjects and other patients with brain injury), our results call for a reconsideration of blindsight, and, arguably also of many previous studies of unconscious perception in healthy subjects.

The Early ANTP Gene Repertoire: Insights from the Placozoan Genome:

The evolution of ANTP genes in the Metazoa has been the subject of conflicting hypotheses derived from full or partial gene sequences and genomic organization in higher animals. Whole genome sequences have recently filled in some crucial gaps for the basal metazoan phyla Cnidaria and Porifera. Here we analyze the complete genome of Trichoplax adhaerens, representing the basal metazoan phylum Placozoa, for its set of ANTP class genes. The Trichoplax genome encodes representatives of Hox/ParaHox-like, NKL, and extended Hox genes. This repertoire possibly mirrors the condition of a hypothetical cnidarian-bilaterian ancestor. The evolution of the cnidarian and bilaterian ANTP gene repertoires can be deduced by a limited number of cis-duplications of NKL and “extended Hox” genes and the presence of a single ancestral “ProtoHox” gene.

Clinical Characteristics of 26 Human Cases of Highly Pathogenic Avian Influenza A (H5N1) Virus Infection in China:

While human cases of highly pathogenic avian influenza A (H5N1) virus infection continue to increase globally, available clinical data on H5N1 cases are limited. We conducted a retrospective study of 26 confirmed human H5N1 cases identified through surveillance in China from October 2005 through April 2008. Data were collected from hospital medical records of H5N1 cases and analyzed. The median age was 29 years (range 6-62) and 58% were female. Many H5N1 cases reported fever (92%) and cough (58%) at illness onset, and had lower respiratory findings of tachypnea and dyspnea at admission. All cases progressed rapidly to bilateral pneumonia. Clinical complications included acute respiratory distress syndrome (ARDS, 81%), cardiac failure (50%), elevated aminotransaminases (43%), and renal dysfunction (17%). Fatal cases had a lower median nadir platelet count (64.5×109 cells/L vs 93.0×109 cells/L, p = 0.02), higher median peak lactic dehydrogenase (LDH) level (1982.5 U/L vs 1230.0 U/L, p = 0.001), higher percentage of ARDS (94% [n = 16] vs 56% [n = 5], p = 0.034) and more frequent cardiac failure (71% [n = 12] vs 11% [n = 1], p = 0.011) than nonfatal cases. A higher proportion of patients who received antiviral drugs survived compared to untreated (67% [8/12] vs 7% [1/14], p = 0.003). The clinical course of Chinese H5N1 cases is characterized by fever and cough initially, with rapid progression to lower respiratory disease. Decreased platelet count, elevated LDH level, ARDS and cardiac failure were associated with fatal outcomes. Clinical management of H5N1 cases should be standardized in China to include early antiviral treatment for suspected H5N1 cases.

There are 45 new articles in PLoS ONE this week. 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, including the first one which tests one of Darwin’s own hypotheses:
Resource Competition Triggers the Co-Evolution of Long Tongues and Deep Corolla Tubes:

It is normally thought that deep corolla tubes evolve when a plant’s successful reproduction is contingent on having a corolla tube longer than the tongue of the flower’s pollinators, and that pollinators evolve ever-longer tongues because individuals with longer tongues can obtain more nectar from flowers. A recent model shows that, in the presence of pollinators with long and short tongues that experience resource competition, coexisting plant species can diverge in corolla-tube depth, because this increases the proportion of pollen grains that lands on co-specific flowers. We have extended the model to study whether resource competition can trigger the co-evolution of tongue length and corolla-tube depth. Starting with two plant and two pollinator species, all of them having the same distribution of tongue length or corolla-tube depth, we show that variability in corolla-tube depth leads to divergence in tongue length, provided that increasing tongue length is not equally costly for both species. Once the two pollinator species differ in tongue length, divergence in corolla-tube depth between the two plant species ensues. Co-evolution between tongue length and corolla-tube depth is a robust outcome of the model, obtained for a wide range of parameter values, but it requires that tongue elongation is substantially easier for one pollinator species than for the other, that pollinators follow a near-optimal foraging strategy, that pollinators experience competition for resources and that plants experience pollination limitation.

Owls May Use Faeces and Prey Feathers to Signal Current Reproduction:

Many animals communicate by marking focal elements of their home range with different kinds of materials. Visual signaling has been demonstrated to play a previously unrecognized role in the intraspecific communication of eagle owls (Bubo bubo), in both territorial and parent-offspring contexts. Visual signals may play a role in a variety of circumstances in this crepuscular and nocturnal species. Here, we report that a large amount of extremely visible white faeces and prey feathers appear during the breeding season on posts and plucking sites in proximity to the nest, potentially representing a way for eagle owls to mark their territory. We present descriptive and experimental evidence showing that faeces and prey remains could act as previously unrecognized visual signals in a nocturnal avian predator. This novel signaling behavior could indicate the owls’ current reproductive status to potential intruders, such as other territorial owls or non-breeding floaters. Faeces and prey feather markings may also advertise an owl’s reproductive status or function in mate-mate communication. We speculate that faeces marks and plucking may represent an overlooked but widespread method for communicating current reproduction to conspecifics. Such marking behavior may be common in birds, and we may now be exploring other questions and mechanisms in territoriality.

Phase Shift from a Coral to a Corallimorph-Dominated Reef Associated with a Shipwreck on Palmyra Atoll:

Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives.

Adaptive Melanin Response of the Soil Fungus Aspergillus niger to UV Radiation Stress at “Evolution Canyon”, Mount Carmel, Israel:

Adaptation is an evolutionary process in which traits in a population are tailored by natural selection to better meet the challenges presented by the local environment. The major discussion relating to natural selection concerns the portraying of the cause and effect relationship between a presumably adaptive trait and selection agents generating it. Therefore, it is necessary to identify trait(s) that evolve in direct response to selection, enhancing the organism’s fitness. “Evolution Canyon” (EC) in Israel mirrors a microcosmic evolutionary system across life and is ideal to study natural selection and local adaptation under sharply, microclimatically divergent environments. The south-facing, tropical, sunny and xeric “African” slope (AS) receives 200%-800% higher solar radiation than the north-facing, temperate, shady and mesic “European” slope (ES), 200 meters apart. Thus, solar ultraviolet radiation (UVR) is a major selection agent in EC influencing the organism-environment interaction. Melanin is a trait postulated to have evolved for UV-screening in microorganisms. Here we investigate the cause and effect relationship between differential UVR on the opposing slopes of EC and the conidial melanin concentration of the filamentous soil fungus Aspergillus niger. We test the working hypothesis that the AS strains exhibit higher melanin content than strains from the ES resulting in higher UV resistance. We measured conidial melanin concentration of 80 strains from the EC using a spectrophotometer. The results indicated that mean conidial melanin concentration of AS strains were threefold higher than ES strains and the former resisted UVA irradiation better than the latter. Comparisons of melanin in the conidia of A. niger strains from sunny and shady microniches on the predominantly sunny AS and predominantly shady ES indicated that shady conditions on the AS have no influence on the selection on melanin; in contrast, the sunny strains from the ES displayed higher melanin concentrations. We conclude that melanin in A. niger is an adaptive trait against UVR generated by natural selection.

The Silkworm (Bombyx mori) microRNAs and Their Expressions in Multiple Developmental Stages:

MicroRNAs (miRNAs) play crucial roles in various physiological processes through post-transcriptional regulation of gene expressions and are involved in development, metabolism, and many other important molecular mechanisms and cellular processes. The Bombyx mori genome sequence provides opportunities for a thorough survey for miRNAs as well as comparative analyses with other sequenced insect species. We identified 114 non-redundant conserved miRNAs and 148 novel putative miRNAs from the B. mori genome with an elaborate computational protocol. We also sequenced 6,720 clones from 14 developmental stage-specific small RNA libraries in which we identified 35 unique miRNAs containing 21 conserved miRNAs (including 17 predicted miRNAs) and 14 novel miRNAs (including 11 predicted novel miRNAs). Among the 114 conserved miRNAs, we found six pairs of clusters evolutionarily conserved cross insect lineages. Our observations on length heterogeneity at 5′ and/or 3′ ends of nine miRNAs between cloned and predicted sequences, and three mature forms deriving from the same arm of putative pre-miRNAs suggest a mechanism by which miRNAs gain new functions. Analyzing development-related miRNAs expression at 14 developmental stages based on clone-sampling and stem-loop RT PCR, we discovered an unusual abundance of 33 sequences representing 12 different miRNAs and sharply fluctuated expression of miRNAs at larva-molting stage. The potential functions of several stage-biased miRNAs were also analyzed in combination with predicted target genes and silkworm’s phenotypic traits; our results indicated that miRNAs may play key regulatory roles in specific developmental stages in the silkworm, such as ecdysis. Taking a combined approach, we identified 118 conserved miRNAs and 151 novel miRNA candidates from the B. mori genome sequence. Our expression analyses by sampling miRNAs and real-time PCR over multiple developmental stages allowed us to pinpoint molting stages as hotspots of miRNA expression both in sorts and quantities. Based on the analysis of target genes, we hypothesized that miRNAs regulate development through a particular emphasis on complex stages rather than general regulatory mechanisms.

Matched Filters, Mate Choice and the Evolution of Sexually Selected Traits:

Fundamental for understanding the evolution of communication systems is both the variation in a signal and how this affects the behavior of receivers, as well as variation in preference functions of receivers, and how this affects the variability of the signal. However, individual differences in female preference functions and their proximate causation have rarely been studied. Calling songs of male field crickets represent secondary sexual characters and are subject to sexual selection by female choice. Following predictions from the “matched filter hypothesis” we studied the tuning of an identified interneuron in a field cricket, known for its function in phonotaxis, and correlated this with the preference of the same females in two-choice trials. Females vary in their neuronal frequency tuning, which strongly predicts the preference in a choice situation between two songs differing in carrier frequency. A second “matched filter” exists in directional hearing, where reliable cues for sound localization occur only in a narrow frequency range. There is a strong correlation between the directional tuning and the behavioural preference in no-choice tests. This second “matched filter” also varies widely in females, and surprisingly, differs on average by 400 Hz from the neuronal frequency tuning. Our findings on the mismatch of the two “matched filters” would suggest that the difference in these two filters appears to be caused by their evolutionary history, and the different trade-offs which exist between sound emission, transmission and detection, as well as directional hearing under specific ecological settings. The mismatched filter situation may ultimately explain the maintenance of considerable variation in the carrier frequency of the male signal despite stabilizing selection.

Evidence of the Importance of Host Habitat Use in Predicting the Dilution Effect of Wild Boar for Deer Exposure to Anaplasma spp:

Foci of tick-borne pathogens occur at fine spatial scales, and depend upon a complex arrangement of factors involving climate, host abundance and landscape composition. It has been proposed that the presence of hosts that support tick feeding but not pathogen multiplication may dilute the transmission of the pathogen. However, models need to consider the spatial component to adequately explain how hosts, ticks and pathogens are distributed into the landscape.
In this study, a novel, lattice-derived, behavior-based, spatially-explicit model was developed to test how changes in the assumed perception of different landscape elements affect the outcome of the connectivity between patches and therefore the dilution effect. The objective of this study was to explain changes in the exposure rate (ER) of red deer to Anaplasma spp. under different configurations of suitable habitat and landscape fragmentation in the presence of variable densities of the potentially diluting host, wild boar. The model showed that the increase in habitat fragmentation had a deep impact on Habitat Sharing Ratio (HSR), a parameter describing the amount of habitat shared by red deer and wild boar, weighted by the probability of the animals to remain together in the same patch (according to movement rules), the density of ticks and the density of animals at a given vegetation patch, and decreased the dilution effect of wild boar on deer Anaplasma ER.
The model was validated with data collected on deer, wild boar and tick densities, climate, landscape composition, host vegetation preferences and deer seropositivity to Anaplasma spp. (as a measure of ER) in 10 study sites in Spain. However, although conditions were appropriate for a dilution effect, empirical results did not show a decrease in deer ER in sites with high wild boar densities. The model showed that the HSR was the most effective parameter to explain the absence of the dilution effect. These results suggest that host habitat usage may weaken the predicted dilution effect for tick-borne pathogens and emphasize the importance of the perceptual capabilities of different hosts in different landscapes and habitat fragmentation conditions for predictions of dilution effects.

Stochastic and Regulatory Role of Chromatin Silencing in Genomic Response to Environmental Changes:

Phenotypic diversity and fidelity can be balanced by controlling stochastic molecular mechanisms. Epigenetic silencing is one that has a critical role in stress response. Here we show that in yeast, incomplete silencing increases stochastic noise in gene expression, probably owing to unstable chromatin structure. Telomere position effect is suggested as one mechanism. Expression diversity in a population achieved in this way may render a subset of cells to readily respond to various acute stresses. By contrast, strong silencing tends to suppress noisy expression of genes, in particular those involved in life cycle control. In this regime, chromatin may act as a noise filter for precisely regulated responses to environmental signals that induce huge phenotypic changes such as a cell fate transition. These results propose modulation of chromatin stability as an important determinant of environmental adaptation and cellular differentiation.

Culture Shapes How We Look at Faces:

Face processing, amongst many basic visual skills, is thought to be invariant across all humans. From as early as 1965, studies of eye movements have consistently revealed a systematic triangular sequence of fixations over the eyes and the mouth, suggesting that faces elicit a universal, biologically-determined information extraction pattern. Here we monitored the eye movements of Western Caucasian and East Asian observers while they learned, recognized, and categorized by race Western Caucasian and East Asian faces. Western Caucasian observers reproduced a scattered triangular pattern of fixations for faces of both races and across tasks. Contrary to intuition, East Asian observers focused more on the central region of the face. These results demonstrate that face processing can no longer be considered as arising from a universal series of perceptual events. The strategy employed to extract visual information from faces differs across cultures.

Habitat-Specific Population Growth of a Farmland Bird:

To assess population persistence of species living in heterogeneous landscapes, the effects of habitat on reproduction and survival have to be investigated. We used a matrix population model to estimate habitat-specific population growth rates for a population of northern wheatears Oenanthe oenanthe breeding in farmland consisting of a mosaic of distinct habitat (land use) types. Based on extensive long-term data on reproduction and survival, habitats characterised by tall field layers (spring- and autumn-sown crop fields, ungrazed grasslands) displayed negative stochastic population growth rates (log λs: −0.332, −0.429, −0.168, respectively), that were markedly lower than growth rates of habitats characterised by permanently short field layers (pastures grazed by cattle or horses, and farmyards, log λs: −0.056, +0.081, −0.059). Although habitats differed with respect to reproductive performance, differences in habitat-specific population growth were largely due to differences in adult and first-year survival rates, as shown by a life table response experiment (LTRE). Our results show that estimation of survival rates is important for realistic assessments of habitat quality. Results also indicate that grazed grasslands and farmyards may act as source habitats, whereas crop fields and ungrazed grasslands with tall field layers may act as sink habitats. We suggest that the strong decline of northern wheatears in Swedish farmland may be linked to the corresponding observed loss of high quality breeding habitat, i.e. grazed semi-natural grasslands.

Gene Expression Disruptions of Organism versus Organ in Drosophila Species Hybrids:

Hybrid dysfunctions, such as sterility, may result in part from disruptions in the regulation of gene expression. Studies of hybrids within the Drosophila simulans clade have reported genes expressed above or below the expression observed in their parent species, and such misexpression is associated with male sterility in multigenerational backcross hybrids. However, these studies often examined whole bodies rather than testes or had limited replication using less-sensitive but global techniques. Here, we use a new RNA isolation technique to re-examine hybrid gene expression disruptions in both testes and whole bodies from single Drosophila males by real-time quantitative RT-PCR. We find two early-spermatogenesis transcripts are underexpressed in hybrid whole-bodies but not in assays of testes alone, while two late-spermatogenesis transcripts seem to be underexpressed in both whole-bodies and testes alone. Although the number of transcripts surveyed is limited, these results provide some support for a previous hypothesis that the spermatogenesis pathway in these sterile hybrids may be disrupted sometime after the expression of the early meiotic arrest genes.

Sweets Make Young Horses Harder To Train, Study Finds:

Young horses may be easier to train if they temporarily lay off the sweets, says a Montana State University study where two-year-olds wore pedometers, wrist watches and Ace bandages. A commercial mixture of corn, oats, barley and molasses — sometimes called “sweet grain” or “sweet feed” — gives horses the glossy coat and lively spirit that makes them attractive to prospective buyers, said Jan Bowman, an animal nutritionist at MSU.

Mirror Self-recognition In Magpie Birds:

Self-recognition, it has been argued, is a hallmark of advanced cognitive abilities in animals. It was previously thought that only the usual suspects of higher cognition–some great apes, dolphins, and elephants–were able to recognize their own bodies in a mirror.

DEET’s Not Sweet To Mosquitoes, Groundbreaking Research Shows:

Spray yourself with a DEET-based insect repellent and the mosquitoes will leave you alone. But why? They flee because of their intense dislike for the smell of the chemical repellent and not because DEET jams their sense of smell, report researchers at the University of California, Davis.

Key Photosynthesis Step Replicated: Scientists Learn From Nature To Split Water Into Hydrogen And Oxygen:

An international team of researchers led by Monash University has used chemicals found in plants to replicate a key process in photosynthesis paving the way to a new approach that uses sunlight to split water into hydrogen and oxygen.

Trees, Forests And The Eiffel Tower Reveal Theory Of Design In Nature:

What do a tree and the Eiffel Tower have in common? According to a Duke University engineer, both are optimized for flow. In the case of trees, the flow is of water from the ground throughout the trunk, branches and leaves, and into the air. The Eiffel Tower’s flow carries stresses throughout the structure without collapsing under its own weight or being downed by the wind.

Light Receptors In Eye Play Key Role In Setting Biological Clock, Study Shows:

Biologists at the University of Virginia have discovered a switching mechanism in the eye that plays a key role in regulating the sleep/wake cycles in mammals.

A Therapy For Baby Boomers To Sleep On: New Drug For Insomniacs Over 55:

If you’re over 55 and have spent more than a few sleepless nights, you’re not alone — insomnia affects about half of all people over 55 — but you may also be at increased risk for physical and mental ailments.

Why An Exciting Book Is Just As Thrilling As A Hair-raising Movie:

Watching Keanu Reeves walk along the ledge of a skyscraper and lose his footing in The Matrix can make us skip a heartbeat or sweat, as if we were risking our own life. This sharing of other people’s emotions in movies has been shown to depend on the fact that observers the same brain regions are activated in the observers when they feel an emotion and when they see someone else experience a similar emotion.

Parents’ Expectations, Styles Can Harm College Students’ Self-esteem:

Mom and Dad are going to flip out over my 3.3 GPA and failure to land a top internship. Such anxieties, common among college students, can harm self-esteem and make it more difficult to adjust to school. But a new University of Central Florida study has found that students’ anxieties often are based on exaggerated perceptions of what their parents expect.

Study Examines The Psychology Behind Students Who Don’t Cheat:

While many studies have examined cheating among college students, new research looks at the issue from a different perspective – identifying students who are least likely to cheat.

Antidepressants May Impair Driving Ability, New Research Finds:

People taking prescription antidepressants appear to drive worse than people who aren’t taking such drugs, and depressed people on antidepressants have even more trouble concentrating and reacting behind the wheel.

Playing Video Games Offers Learning Across Life Span, Say Studies:

Certain types of video games can have beneficial effects, improving gamers’ dexterity as well as their ability to problem-solve – attributes that have proven useful not only to students but to surgeons, according to research recently discussed at the Annual Convention of the American Psychological Association.

Adults Easily Fooled By Children’s False Denials, Study Finds:

Adults are easily fooled when a child denies that an actual event took place, but do somewhat better at detecting when a child makes up information about something that never happened, according to new research from the University of California, Davis.

Aboriginal Kids Can Count Without Numbers:

Knowing the words for numbers is not necessary to be able to count, according to a new study of aboriginal children by UCL (University College London) and the University of Melbourne. The study of the aboriginal children – from two communities which do not have words or gestures for numbers – found that they were able to copy and perform number-related tasks.

Young Children’s ‘Theory Of Mind’ Linked To Subsequent Metacognitive Development In Adolescence:

Metacognition refers to the awareness of one’s knowledge in different areas. The more comprehensive and accurate this metacognitive knowledge, the better one is able to reflect about his or her own actions and behaviors. “Theory of Mind” (ToM) deals with very young children’s understanding of mental life and the ability to estimate mental states.

Some really cool stuff just got published a few minutes ago in PLoS Biology:
A cool paper: Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition:

A crucial step in the emergence of self-recognition is the understanding that one’s own mirror reflection does not represent another individual but oneself. In nonhuman species and in children, the “mark test” has been used as an indicator of self-recognition. In these experiments, subjects are placed in front of a mirror and provided with a mark that cannot be seen directly but is visible in the mirror. Mirror self-recognition has been shown in apes and, recently, in dolphins and elephants. Although experimental evidence in nonmammalian species has been lacking, some birds from the corvid family show skill in tasks that require perspective taking, a likely prerequisite for the occurrence of mirror self-recognition. Using the mark test, we obtained evidence for mirror self-recognition in the European Magpie, Pica pica. This finding shows that elaborate cognitive skills arose independently in corvids and primates, taxonomic groups with an evolutionary history that diverged about 300 million years ago. It further proves that the neocortex is not a prerequisite for self-recognition.

Read the accompanying ‘Primer’ by Frans B. M. de Waal: The Thief in the Mirror:

The Eurasian magpie (Pica pica) has a poor reputation. As a child, I learned never to leave small shiny objects, such as teaspoons, unattended outdoors as these raucous birds will steal anything they can put their beaks on. This folklore even inspired a Rossini opera, “La gazza ladra” (“The Thieving Magpie”). Nowadays, this view has been replaced with one that is more sensitive to ecological balance, in which magpies are depicted as murderous plunderers of the nests of innocent songbirds. Either way, they are black-and-white gangsters.
But no one has ever accused a magpie of being stupid. The bird belongs to the Corvidae, a worldwide family (also including crows, ravens, jackdaws, jays, and nutcrackers) marked by an exceptionally large forebrain, which permits innovative foraging [1]. In recent years, this family has begun to pose a challenge to the idea that primates constitute the pinnacle of cognitive evolution by showing creative tool-use, visual perspective-taking, foresight, and so on.

And a book review: Redefining “Natural” in Agriculture:

The place of genetically modified crops in sustainable agriculture has been the subject of heated debate for decades. A new book takes an innovative approach to this debate by presenting the perspectives of an unlikely pair of co-authors [1]. Pam Ronald is a plant molecular biologist, genetic engineer, and supporter of genetically engineering crops for the benefit of humanity. Raoul Adamchak is an organic farmer. Given the known antagonism of many organic advocates to genetically engineered (GE) crops, one would not have thought these two authors would be able to provide an agreed text. But Adamchak is married to Ronald and, to judge from the text, happily so. The authorship of the individual chapters alternates between the two. The subject matter deals with organic farming methods, GE methods, questions of environmental conservation, risk, trust, and ownership of seeds and genes. The last chapter, and the only one written jointly, concludes that some marriage of organic and GE technology will represent the agriculture of the future.

Snooze Button For Body’s Circadian Clock:

We may use the snooze button to fine-tune our sleep cycles, but our cells have a far more meticulous and refined system. Humans, and most other organisms, have 24-hour rhythms that are regulated by a precise molecular clock that ticks inside every cell. After decades of study, researchers are still identifying all the gears involved in running this “circadian” clock and are working to put each of the molecular cogs in its place. A new study by Rockefeller University scientists now shows how two of the key molecules interact to regulate the clock’s cycle and uncovers how that switch can go haywire, identifying one potential cause of heritable sleep disorders.

Stone Age Graveyard Reveals Lifestyles Of A ‘Green Sahara’:

The largest Stone Age graveyard found in the Sahara, which provides an unparalleled record of life when the region was green, has been discovered in Niger by National Geographic Explorer-in-Residence and University of Chicago Professor Paul Sereno, whose team first happened on the site during a dinosaur-hunting expedition.

Big-brained Animals Evolve Faster:

Ever since Darwin, evolutionary biologists have wondered why some lineages have diversified more than others. A classical explanation is that a higher rate of diversification reflects increased ecological opportunities that led to a rapid adaptive radiation of a clade.

Burmese Pythons Will Find Little Suitable Habitat Outside South Florida, Study Suggests:

Burmese Pythons – one of the largest snakes in the world – may have chosen Florida as a vacation destination, but are unlikely to expand further, according to a new study by researchers at the City University of New York (CUNY. Although the United States Geological Survey (USGS) earlier this year released ‘climate maps’ indicating that the pythons could potentially inhabit up to thirty two states in the continental U.S., new research indicates that the snakes are unlikely to expand out of south Florida.

In The Long Run, Exertion Regulation Wins The Day For Marathon Runners:

Long-distance running is widely seen as one of the great physical challenges a human can undertake and as the 2008 Summer Olympics commence in Beijing on August 8, many eager sports fans will await with baited breath the last event of the Games – the men’s marathon, held on August 24.

Timing Of Political Messages Influences Voter Preferences, Researcher Finds:

In political campaigns, timing is almost everything. Candidates communicate with voters over a long period of time before voters actually vote. What candidates say to these voters is, of course, important, but it turns out that when they say it also influences voter preferences. Why Obama’s reliance on lofty rhetoric has succeeded thus far is a puzzle addressed in the paper “It’s Time to Vote: The Effect of Matching Message Orientation and Temporal Frame on Political Persuasion,” forthcoming in the Journal of Consumer Research. The research, co-authored by the University of Minnesota’s Akshay Rao, Hakkyun Kim (Concordia) and Angela Lee (Northwestern), demonstrates that the timing and content of political messages affects voters, particularly swing voters.

Distinguishing Between Two Birds Of A Feather:

The bird enthusiast who chronicled the adventures of a flock of red-headed conures in his book “The Wild Parrots of Telegraph Hill” knows most of the parrots by name, yet most of us would be hard pressed to tell one bird from another. While it has been known for a long time that we can become acutely attuned to our day-to-day environment, the underlying neural mechanism has been less clear.

Resistant Prions: Can They Be Transmitted By Environment As Well As Direct Contact?:

Prions, the pathogens that cause scrapie in sheep, can survive in the ground for several years, as researchers have discovered. Animals can become infected via contaminated pastures. It is not yet known whether the pathogens that cause BSE and CWD are equally resistant.

New Bird Species Discovered In Gabon, Africa:

Scientists at the Smithsonian Institution have discovered a new species of bird in Gabon, Africa, that was, until now, unknown to the scientific community.

Hybrid ‘Muttsucker’ Has Genes Of Three Species:

If you have driven Wyoming Highway 789 between Creston Junction and Baggs, you’ve seen Muddy Creek. Or maybe you haven’t. “It’s a pretty inconspicuous stream,” says David B. McDonald, an associate professor in the University of Wyoming’s Department of Zoology and Physiology. “In fact, when you look at the creek, a lot of times you have trouble even seeing any water.” What’s happening in the murky waters of the appropriately-named creek also is not readily noticeable: An introduced species of fish is threatening the existence of two native Wyoming fish species — the flannelmouth sucker and the bluehead sucker.

So, let’s see what’s new in PLoS Genetics, PLoS Computational Biology, PLoS Pathogens and PLoS Neglected Tropical Diseases this week. 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:

Continue reading →

Sleep Selectively Preserves Emotional Memories:

As poets, songwriters and authors have described, our memories range from misty water-colored recollections to vividly detailed images of the times of our lives. Now, a study led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and Boston College offers new insights into the specific components of emotional memories, suggesting that sleep plays a key role in determining what we remember – and what we forget.

Hard Day’s Night? Enhancing The Work-life Balance Of Shift Workers:

Introducing a Compressed Working Week may enhance the work-life balance of shift workers without damaging productivity or competitiveness suggests a new systematic review published in the Journal of Epidemiology and Community Health.

Causes For Sexual Dysfunction Change As People Age:

Sexual dysfunction is not an inevitable part of aging, but it is strongly related a number of factors, such as mental and physical health, demographics and lifetime experiences, many of which are interrelated, according to a new study by researchers at the University of Chicago.

Microbes, By Latitudes And Altitudes, Shed New Light On Life’s Diversity:

Microbial biologists, including the University of Oregon’s Jessica L. Green, may not have Jimmy Buffett’s music from 1977 in mind, but they are changing attitudes about evolutionary diversity on Earth, from oceanic latitudes to mountainous altitudes.

Is It Too Late To Save The Great Migrations?:

Long gone are the days when hundreds of thousands of bison grazed the Great Plains, millions of passenger pigeons darkened the skies while migrating to and from their breeding grounds, and some 12.5 trillion Rocky Mountain locusts crowded an area exceeding the size of California.

How Flesh-eating Bacteria Attack The Body’s Immune System:

“Flesh-eating” or “Strep” bacteria are able to survive and spread in the body by degrading a key immune defense molecule, according to researchers at the University of California, San Diego, School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences.

How DNA Repairs Can Reshape Genome, Spawn New Species:

Researchers at Duke University Medical Center and at the National Institute of Environmental Health Sciences (NIEHS) have shown how broken sections of chromosomes can recombine to change genomes and spawn new species.

Cocaine-induced Synaptic Plasticity Linked To Persistent Addictive Behaviors:

The persistent nature of addiction is its most devastating feature. Understanding the mechanism underlying this phenomenon is the key for designing efficient therapy.

Oil And Gas Projects In Western Amazon Threaten Biodiversity And Indigenous Peoples:

The western Amazon, home to the most biodiverse and intact rainforest left on Earth, may soon be covered with oil rigs and pipelines.

Southern Ocean Seals Dive Deep For Climate Data:

According to a paper published today by a team of French, Australian, US and British scientists in the Proceedings of the National Academy of Sciences, elephant seals fitted with special oceanographic sensors are providing a 30-fold increase in data recorded in parts of the Southern Ocean rarely observed using traditional ocean monitoring techniques.

Birds Move Farther North; Climate Change Link Considered:

A study by researchers at the SUNY College of Environmental Science and Forestry (ESF) has documented, for the first time in the northeastern United States, that a variety of bird species are extending their breeding ranges to the north, a pattern that adds to concerns about climate change. Focusing on 83 species of birds that have traditionally bred in New York state, the researchers compared data collected in the early 1980s with information gathered between 2000 and 2005. They discovered that many species had extended their range boundaries, some by as much as 40 miles.

How Non-stick Bugs Evade Natural Fly Paper:

There are few things more irritating than a fly buzzing around the house. South Africans have an unconventional solution to the problem. They hang up a bunch of Roridula gorgonias leaves. Attracted to the shiny adhesive droplets on the leaf’s hairs, the hapless pest is soon trapped by the natural flypaper.

New Group Of Plant Hormones Discovered:

Scientists from the Wageningen University Laboratory of Plant Physiology and an international team of scientists have discovered a new group of plant hormones, the so-called strigolactones. This group of chemicals is known to be involved in the interaction between plants and their environment.

Global Warming Will Do Little To Change Hurricane Activity, According To New Model:

In a study published in the July 2008 issue of Geophysical Research Letters, Drs. David S. Nolan and Eric D. Rappin from the University of Miami’s Rosenstiel School of Marine and Atmospheric Science describe a new method for evaluating the frequency of hurricane formation in present and future tropical climates.

Contraceptive Pill Influences Partner Choice:

The contraceptive pill may disrupt women’s natural ability to choose a partner genetically dissimilar to themselves, research at the University of Liverpool has found.

Levels Of C-reactive Protein In The Blood Do Not Cause Diabetes:

Eric Brunner from the Royal Free and University College London Medical School, London, and colleagues, examine the association between levels of C-reactive protein, a marker for inflammation in the blood, and the risk of type 2 diabetes.

High-Altitude Small Mammals Of The Great Basin Are Not Completely Isolated:

The term “sky islands” sounds intriguing, but it may be more lyrical than useful when discussing mammal distributions, according to new research from Eric Waltari of the Sackler Institute of Comparative Genomics at the American Museum of Natural History and Robert Guralnick from the University of Colorado at Boulder.

Smells Like Bees’ Spirit:

Bumblebees choose whether to search for food according to how stocked their nests are, say scientists from Queen Mary, University of London.

Water Is No Passive Spectator Of Biological Processes: It Is An Active Participant:

Water is no passive spectator of biological processes; it is an active participant. Protein folding is thus a self-organized process in which the actions of the solvent play a key role. So far, the emphasis in studies of protein folding processes has been on observation of the protein backbone and its side chains.

With Skate Eyes, Scientists Peer Into Human Disease:

Paradoxically, the photoreceptor cells in our retinas release more of their neurotransmitter, glutamate, in the dark, when there is nothing to see, than they do in the light. This is doubly surprising since although glutamate is a major signaling molecule in the retina and throughout the central nervous system, it is also a potent cytotoxin that, in large doses, can kill nearby cells.

There are 57 new articles in PLoS ONE this week. 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:
How Do Humans Control Physiological Strain during Strenuous Endurance Exercise?:

Distance running performance is a viable model of human locomotion. To evaluate the physiologic strain during competitions ranging from 5-100 km, we evaluated heart rate (HR) records of competitive runners (n = 211). We found evidence that: 1) physiologic strain (% of maximum HR (%HRmax)) increased in proportional manner relative to distance completed, and was regulated by variations in running pace; 2) the %HRmax achieved decreased with relative distance; 3) slower runners had similar %HRmax response within a racing distance compared to faster runners, and despite differences in pace, the profile of %HRmax during a race was very similar in runners of differing ability; and 4) in cases where there was a discontinuity in the running performance, there was evidence that physiologic effort was maintained for some time even after the pace had decreased. The overall results suggest that athletes are actively regulating their relative physiologic strain during competition, although there is evidence of poor regulation in the case of competitive failures.

Oil and Gas Projects in the Western Amazon: Threats to Wilderness, Biodiversity, and Indigenous Peoples:

The western Amazon is the most biologically rich part of the Amazon basin and is home to a great diversity of indigenous ethnic groups, including some of the world’s last uncontacted peoples living in voluntary isolation. Unlike the eastern Brazilian Amazon, it is still a largely intact ecosystem. Underlying this landscape are large reserves of oil and gas, many yet untapped. The growing global demand is leading to unprecedented exploration and development in the region. We synthesized information from government sources to quantify the status of oil development in the western Amazon. National governments delimit specific geographic areas or “blocks” that are zoned for hydrocarbon activities, which they may lease to state and multinational energy companies for exploration and production. About 180 oil and gas blocks now cover ~688,000 km2 of the western Amazon. These blocks overlap the most species-rich part of the Amazon. We also found that many of the blocks overlap indigenous territories, both titled lands and areas utilized by peoples in voluntary isolation. In Ecuador and Peru, oil and gas blocks now cover more than two-thirds of the Amazon. In Bolivia and western Brazil, major exploration activities are set to increase rapidly. Without improved policies, the increasing scope and magnitude of planned extraction means that environmental and social impacts are likely to intensify. We review the most pressing oil- and gas-related conservation policy issues confronting the region. These include the need for regional Strategic Environmental Impact Assessments and the adoption of roadless extraction techniques. We also consider the conflicts where the blocks overlap indigenous peoples’ territories.

Claims of Potential Expansion throughout the U.S. by Invasive Python Species Are Contradicted by Ecological Niche Models:

Recent reports from the United States Geological Survey (USGS) suggested that invasive Burmese pythons in the Everglades may quickly spread into many parts of the U.S. due to putative climatic suitability. Additionally, projected trends of global warming were predicted to significantly increase suitable habitat and promote range expansion by these snakes. However, the ecological limitations of the Burmese python are not known and the possible effects of global warming on the potential expansion of the species are also unclear. Here we show that a predicted continental expansion is unlikely based on the ecology of the organism and the climate of the U.S. Our ecological niche models, which include variables representing climatic extremes as well as averages, indicate that the only suitable habitat in the U.S. for Burmese pythons presently occurs in southern Florida and in extreme southern Texas. Models based on the current distribution of the snake predict suitable habitat in essentially the only region in which the snakes are found in the U.S. Future climate models based on global warming forecasts actually indicate a significant contraction in suitable habitat for Burmese pythons in the U.S. as well as in their native range. The Burmese python is strongly limited to the small area of suitable environmental conditions in the United States it currently inhabits due to the ecological niche preferences of the snake. The ability of the Burmese python to expand further into the U.S. is severely limited by ecological constraints. Global warming is predicted to significantly reduce the area of suitable habitat worldwide, underscoring the potential negative effects of climate change for many species.

Ocean Surface Winds Drive Dynamics of Transoceanic Aerial Movements:

Global wind patterns influence dispersal and migration processes of aerial organisms, propagules and particles, which ultimately could determine the dynamics of colonizations, invasions or spread of pathogens. However, studying how wind-mediated movements actually happen has been hampered so far by the lack of high resolution global wind data as well as the impossibility to track aerial movements. Using concurrent data on winds and actual pathways of a tracked seabird, here we show that oceanic winds define spatiotemporal pathways and barriers for large-scale aerial movements. We obtained wind data from NASA SeaWinds scatterometer to calculate wind cost (impedance) models reflecting the resistance to the aerial movement near the ocean surface. We also tracked the movements of a model organism, the Cory’s shearwater (Calonectris diomedea), a pelagic bird known to perform long distance migrations. Cost models revealed that distant areas can be connected through “wind highways” that do not match the shortest great circle routes. Bird routes closely followed the low-cost “wind-highways” linking breeding and wintering areas. In addition, we found that a potential barrier, the near surface westerlies in the Atlantic sector of the Intertropical Convergence Zone (ITCZ), temporally hindered meridional trans-equatorial movements. Once the westerlies vanished, birds crossed the ITCZ to their winter quarters. This study provides a novel approach to investigate wind-mediated movements in oceanic environments and shows that large-scale migration and dispersal processes over the oceans can be largely driven by spatiotemporal wind patterns.

A Thirty Million Year-Old Inherited Heteroplasmy:

Due to essentially maternal inheritance and a bottleneck effect during early oogenesis, newly arising mitochondrial DNA (mtDNA) mutations segregate rapidly in metazoan female germlines. Consequently, heteroplasmy (i.e. the mixture of mtDNA genotypes within an organism) is generally resolved to homoplasmy within a few generations. Here, we report an exceptional transpecific heteroplasmy (predicting an alanine/valine alloacceptor tRNA change) that has been stably inherited in oniscid crustaceans for at least thirty million years. Our results suggest that this heteroplasmy is stably transmitted across generations because it occurs within mitochondria and therefore escapes the mtDNA bottleneck that usually erases heteroplasmy. Consistently, at least two oniscid species possess an atypical trimeric mitochondrial genome, which provides an adequate substrate for the emergence of a constitutive intra-mitochondrial heteroplasmy. Persistence of a mitochondrial polymorphism on such a deep evolutionary timescale suggests that balancing selection may be shaping mitochondrial sequence evolution in oniscid crustaceans.

Sleep Modulates the Neural Substrates of Both Spatial and Contextual Memory Consolidation:

It is known that sleep reshapes the neural representations that subtend the memories acquired while navigating in a virtual environment. However, navigation is not process-pure, as manifold learning components contribute to performance, notably the spatial and contextual memory constituents. In this context, it remains unclear whether post-training sleep globally promotes consolidation of all of the memory components embedded in virtual navigation, or rather favors the development of specific representations. Here, we investigated the effect of post-training sleep on the neural substrates of the consolidation of spatial and contextual memories acquired while navigating in a complex 3D, naturalistic virtual town. Using fMRI, we mapped regional cerebral activity during various tasks designed to tap either the spatial or the contextual memory component, or both, 72 h after encoding with or without sleep deprivation during the first post-training night. Behavioral performance was not dependent upon post-training sleep deprivation, neither in a natural setting that engages both spatial and contextual memory processes nor when looking more specifically at each of these memory representations. At the neuronal level however, analyses that focused on contextual memory revealed distinct correlations between performance and neuronal activity in frontal areas associated with recollection processes after post-training sleep, and in the parahippocampal gyrus associated with familiarity processes in sleep-deprived participants. Likewise, efficient spatial memory was associated with posterior cortical activity after sleep whereas it correlated with parahippocampal/medial temporal activity after sleep deprivation. Finally, variations in place-finding efficiency in a natural setting encompassing spatial and contextual elements were associated with caudate activity after post-training sleep, suggesting the automation of navigation. These data indicate that post-training sleep modulates the neural substrates of the consolidation of both the spatial and contextual memories acquired during virtual navigation.

A Semantic Web Management Model for Integrative Biomedical Informatics:

Data, data everywhere. The diversity and magnitude of the data generated in the Life Sciences defies automated articulation among complementary efforts. The additional need in this field for managing property and access permissions compounds the difficulty very significantly. This is particularly the case when the integration involves multiple domains and disciplines, even more so when it includes clinical and high throughput molecular data. The emergence of Semantic Web technologies brings the promise of meaningful interoperation between data and analysis resources. In this report we identify a core model for biomedical Knowledge Engineering applications and demonstrate how this new technology can be used to weave a management model where multiple intertwined data structures can be hosted and managed by multiple authorities in a distributed management infrastructure. Specifically, the demonstration is performed by linking data sources associated with the Lung Cancer SPORE awarded to The University of Texas MDAnderson Cancer Center at Houston and the Southwestern Medical Center at Dallas. A software prototype, available with open source at http://www.s3db.org, was developed and its proposed design has been made publicly available as an open source instrument for shared, distributed data management. The Semantic Web technologies have the potential to addresses the need for distributed and evolvable representations that are critical for systems Biology and translational biomedical research. As this technology is incorporated into application development we can expect that both general purpose productivity software and domain specific software installed on our personal computers will become increasingly integrated with the relevant remote resources. In this scenario, the acquisition of a new dataset should automatically trigger the delegation of its analysis.

Controlling Population Evolution in the Laboratory to Evaluate Methods of Historical Inference:

Natural populations of known detailed past demographic history are extremely valuable to evaluate methods of historical inference, yet are extremely rare. As an alternative approach, we have generated multiple replicate microsatellite data sets from laboratory-cultured populations of a gonochoric free-living nematode, Caenorhabditis remanei, that were constrained to pre-defined demographic histories featuring different levels of migration among populations or bottleneck events of different magnitudes. These data sets were then used to evaluate the performances of two recently developed population genetics methods, BAYESASS+, that estimates recent migration rates among populations, and BOTTLENECK, that detects the occurrence of recent bottlenecks. Migration rates inferred by BAYESASS+ were generally over-estimates, although these were often included within the confidence interval. Analyses of data sets simulated in-silico, using a model mimicking the laboratory experiments, produced less biased estimates of the migration rates, and showed increased efficiency of the program when the number of loci and sampled genotypes per population was higher. In the replicates for which the pre-bottleneck laboratory-cultured populations did not significantly depart from a mutation/drift equilibrium, an important assumption of the program BOTTLENECK, only a portion of the bottleneck events were detected. This result was confirmed by in-silico simulations mirroring the laboratory bottleneck experiments. More generally, our study demonstrates the feasibility, and highlights some of the limits, of the approach that consists in generating molecular genetic data sets by controlling the evolution of laboratory-reared nematode populations, for the purpose of validating methods inferring population history.

Towards Zero Training for Brain-Computer Interfacing:

Electroencephalogram (EEG) signals are highly subject-specific and vary considerably even between recording sessions of the same user within the same experimental paradigm. This challenges a stable operation of Brain-Computer Interface (BCI) systems. The classical approach is to train users by neurofeedback to produce fixed stereotypical patterns of brain activity. In the machine learning approach, a widely adapted method for dealing with those variances is to record a so called calibration measurement on the beginning of each session in order to optimize spatial filters and classifiers specifically for each subject and each day. This adaptation of the system to the individual brain signature of each user relieves from the need of extensive user training. In this paper we suggest a new method that overcomes the requirement of these time-consuming calibration recordings for long-term BCI users. The method takes advantage of knowledge collected in previous sessions: By a novel technique, prototypical spatial filters are determined which have better generalization properties compared to single-session filters. In particular, they can be used in follow-up sessions without the need to recalibrate the system. This way the calibration periods can be dramatically shortened or even completely omitted for these ‘experienced’ BCI users. The feasibility of our novel approach is demonstrated with a series of online BCI experiments. Although performed without any calibration measurement at all, no loss of classification performance was observed.

Relaxation of Selective Constraints Causes Independent Selenoprotein Extinction in Insect Genomes:

Selenoproteins are a diverse family of proteins notable for the presence of the 21st amino acid, selenocysteine. Until very recently, all metazoan genomes investigated encoded selenoproteins, and these proteins had therefore been believed to be essential for animal life. Challenging this assumption, recent comparative analyses of insect genomes have revealed that some insect genomes appear to have lost selenoprotein genes. In this paper we investigate in detail the fate of selenoproteins, and that of selenoprotein factors, in all available arthropod genomes. We use a variety of in silico comparative genomics approaches to look for known selenoprotein genes and factors involved in selenoprotein biosynthesis. We have found that five insect species have completely lost the ability to encode selenoproteins and that selenoprotein loss in these species, although so far confined to the Endopterygota infraclass, cannot be attributed to a single evolutionary event, but rather to multiple, independent events. Loss of selenoproteins and selenoprotein factors is usually coupled to the deletion of the entire no-longer functional genomic region, rather than to sequence degradation and consequent pseudogenisation. Such dynamics of gene extinction are consistent with the high rate of genome rearrangements observed in Drosophila. We have also found that, while many selenoprotein factors are concomitantly lost with the selenoproteins, others are present and conserved in all investigated genomes, irrespective of whether they code for selenoproteins or not, suggesting that they are involved in additional, non-selenoprotein related functions. Selenoproteins have been independently lost in several insect species, possibly as a consequence of the relaxation in insects of the selective constraints acting across metazoans to maintain selenoproteins. The dispensability of selenoproteins in insects may be related to the fundamental differences in antioxidant defense between these animals and other metazoans.

Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production:

The epidemic of bovine spongiform encephalopathy (BSE) has led to a world-wide drop in the market for beef by-products, such as Meat-and-Bone Meal (MBM), a fat-containing but mainly proteinaceaous product traditionally used as an animal feed supplement. While normal rendering is insufficient, the production of biodiesel from MBM has been suggested to destroy infectivity from transmissible spongiform encephalopathies (TSEs). In addition to producing fuel, this method simultaneously generates a nutritious solid residue. In our study we produced biodiesel from MBM under defined conditions using a modified form of alkaline methanolysis. We evaluated the presence of prion in the three resulting phases of the biodiesel reaction (Biodiesel, Glycerol and Solid Residue) in vitro and in vivo. Analysis of the reaction products from 263K scrapie infected MBM led to no detectable immunoreactivity by Western Blot. Importantly, and in contrast to the biochemical results the solid MBM residue from the reaction retained infectivity when tested in an animal bioassay. Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.

Survival Of The Fittest: Even Cancer Cells Follow The Laws Of Evolution:

Scientists from The Institute of Advanced Studies at Princeton and the University of California discovered that the underlying process in tumor formation is the same as for life itself–evolution. After analyzing a half million gene mutations, the researchers found that although different gene mutations control different cancer pathways, each pathway was controlled by only one set of gene mutations.

New Report Details Historic Mass Extinction Of Amphibians; Humans Worsen Spread Of Deadly Emerging Infectious Disease:

Amphibians, reigning survivors of past mass extinctions, are sending a clear, unequivocal signal that something is wrong, as their extinction rates rise to unprecedented levels, according to a paper published by the Proceedings of the National Academy of Sciences (PNAS). Humans are exacerbating two key natural threats – climate change and a deadly disease that is jumping from one species to another.

Anything But Modest: The Mouse Continues To Contribute To Humankind:

“Big things come in small packages,” the saying goes, and it couldn’t be more true when discussing the mouse. This little creature has become a crucial part of human history through its contributions in understanding human genetics and disease.

If A Street Tree Falls … What Does It Take To Make Sound Policy?:

There’s little debate that, when a tree falls near a city street, it makes a sound. But other questions are more difficult to answer: Who is affected by the falling tree and how? Who is liable for the damage? And who is responsible for deciding how to replace the tree?

Egg P Bodies Protect Maternal Gene Messages:

A cell decides what proteins to make based on the messages it receives from its genome. Sometimes messages are held back to be read later, and in most cell types these delayed messages are stored and eventually marked for destruction in P bodies (processing bodies).

Elephant Memories May Hold Key To Survival:

A recent study by the Wildlife Conservation Society and the Zoological Society of London (ZSL) suggests that old female elephants–and perhaps their memories of distant, life-sustaining sources of food and water–may be the key to survival during the worst of times.

Fry Me Kangaroo Brown, Sport:

Skippy could be on more menus following a report that expanding the kangaroo industry would significantly cut greenhouse gases.

‘Lost Tribe’ Of Clinician-scientists: Medical Doctors Who Do Research Could Be A Dying Breed:

The road from disease research to disease cure isn’t usually a smooth one. One role which bridges the laboratory and the clinic is that of the “clinician-scientist” – a doctor who understands disease both in the patient and in the Petri dish. Yet an editorial published in Disease Models & Mechanisms (DMM), contends that clinician-scientists in the UK and elsewhere are not prospering, but rather are “under threat in a hostile environment.”

Complex Decision? Don’t Sleep On It:

Neither snap judgements nor sleeping on a problem are any better than conscious thinking for making complex decisions, according to new research.

Are Pronghorns Smarter Than Classical European Royalty?:

Over the past two decades, John Byers has proven that female pronghorns are smarter than many humans when it comes to mate selection. Rather than going for the male with the biggest body or most impressive horns, female pronghorns expend a ton of energy searching for the most vigor and best stamina; traits that will give their offspring the greatest chance of success.

Bugs Put The Heat In Chili Peppers:

If you’re a fan of habañero salsa or like to order Thai food spiced to five stars, you owe a lot to bugs, both the crawling kind and ones you can see only with a microscope. New research shows they are the ones responsible for the heat in chili peppers.

Humans Implicated In Prehistoric Animal Extinctions With New Evidence:

Research led by UK and Australian scientists sheds new light on the role that our ancestors played in the extinction of Australia’s prehistoric animals. The new study provides the first evidence that Tasmania’s giant kangaroos and marsupial ‘rhinos’ and ‘leopards’ were still roaming the island when humans first arrived.

Olympic Games: Researchers Explore What Makes Better Athletes, The Physiology Of Performance, And More:

The world-record pace for the marathon continues to improve for both men and women. For men, the record pace for the marathon is now about as fast as the record pace for the 10,000-meter run just after World War II. Today, champion athletes are running more than four times farther at speeds of well under five minutes per mile.

Neurobiologists Discover Individuals Who ‘Hear’ Movement:

Individuals with synesthesia perceive the world in a different way from the rest of us. Because their senses are cross-activated, some synesthetes perceive numbers or letters as having colors or days of the week as possessing personalities, even as they function normally in the world.

Humans’ Response To Risk Can Be Unnecessarily Dangerous:

The traffic light ahead of you is turning yellow. Do you gun the engine and speed through the intersection, trusting that others will wait for their green, or do you slow down and wait your turn?

Perfectly Proportioned Legs Keep Water Striders Striding:

The amazing water strider — known for its ability to walk on water — came within just a hair of sinking into evolutionary oblivion. Scientists in France and the United Kingdom are reporting that the insect’s long, flexible legs have an optimal length that keeps it afloat.

Entomologists Use ‘Love Potion’ To Detect Hidden Cerambycid Beetles:

Cerambycid beetles, also known as long-horned beetles, can cause severe damage to standing trees, logs and lumber. How then might they be promptly detected and their numbers swiftly controlled?

Gene For Sexual Switching In Melons Provides Clues To Evolution Of Sex:

A newly discovered function for a hormone in melons suggests it plays a role in how sexual systems evolve in plants. The study, conducted by French and American scientists, appeared recently in the journal Science.

Nine To Twenty Individual Fire Ant Queens Started U.S. Fire Ant Population:

The current U.S. population of red imported fire ants–which infest millions of acres across the southern states–can be traced back to nine to 20 queens in Mobile, Ala.

For The Birds Or For Me? Why Do Conservationists Really Help Wildlife?:

Volunteers who take part in conservation efforts may do it more for themselves than the wildlife they are trying to protect, a University of Alberta case study shows.

Duck-billed Dinosaurs Outgrew Predators To Survive:

With long limbs and a soft body, the duck-billed hadrosaur had few defenses against predators such as tyrannosaurs. But new research on the bones of this plant-eating dinosaur suggests that it had at least one advantage: It grew to adulthood much faster than its predators, giving it superiority in size.

Massive Numbers Of Critically Endangered Western Lowland Gorillas Discovered In Republic Of Congo:

The world’s population of critically endangered western lowland gorillas recently received a huge boost when the Wildlife Conservation Society released a census showing massive numbers of these secretive great apes alive and well in the Republic of Congo.

Less REM Sleep Associated With Being Overweight Among Children And Teens:

Children and teens who get less sleep, especially those who spend less time in rapid eye movement (REM) sleep, may be more likely to be overweight, according to a new report.

Why The Slow-Paced World Could Make It Difficult To Catch A Ball:

BBSRC researchers at the University of Birmingham have uncovered new information about the way that we perceive fast moving, incoming objects – such as tennis or cricket balls.

Why Some Smokers Become Addicted With Their First Cigarette:

New research from The University of Western Ontario reveals how the brain processes the ‘rewarding’ and addictive properties of nicotine, providing a better understanding of why some people seemingly become hooked with their first smoke.

Acidification Of Sea Hampers Reproduction Of Marine Species:

By absorbing carbon dioxide from the atmosphere, and from the human use of fossil fuels, the world’s seas function as a giant buffer for the Earth’s life support system. The chemical balance of the sea has long been regarded as immovable.

Next Generation Tool For Visualizing Genomic Data Introduced:

Researchers are collecting vast amounts of diverse genomic data with ever-increasing speed, but effective ways to visualize these data in an integrated manner have lagged behind the ability to generate them.

Hot Peppers Really Do Bring The Heat:

Chili peppers can do more than just make you feel hot; the active chemical in peppers can directly induce thermogenesis, the process by which cells convert energy into heat, according to a new study.

Female Guppies Risk Death To Avoid Sexual Harassment:

Sexual harassment from male guppies is so bad that long-suffering females will risk their lives to escape it, according to new research from Dr Safi Darden and Dr Darren Croft from Bangor University.

There are 69 new articles in PLoS ONE this week. 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:
Comparison of Pattern Detection Methods in Microarray Time Series of the Segmentation Clock:

While genome-wide gene expression data are generated at an increasing rate, the repertoire of approaches for pattern discovery in these data is still limited. Identifying subtle patterns of interest in large amounts of data (tens of thousands of profiles) associated with a certain level of noise remains a challenge. A microarray time series was recently generated to study the transcriptional program of the mouse segmentation clock, a biological oscillator associated with the periodic formation of the segments of the body axis. A method related to Fourier analysis, the Lomb-Scargle periodogram, was used to detect periodic profiles in the dataset, leading to the identification of a novel set of cyclic genes associated with the segmentation clock. Here, we applied to the same microarray time series dataset four distinct mathematical methods to identify significant patterns in gene expression profiles. These methods are called: Phase consistency, Address reduction, Cyclohedron test and Stable persistence, and are based on different conceptual frameworks that are either hypothesis- or data-driven. Some of the methods, unlike Fourier transforms, are not dependent on the assumption of periodicity of the pattern of interest. Remarkably, these methods identified blindly the expression profiles of known cyclic genes as the most significant patterns in the dataset. Many candidate genes predicted by more than one approach appeared to be true positive cyclic genes and will be of particular interest for future research. In addition, these methods predicted novel candidate cyclic genes that were consistent with previous biological knowledge and experimental validation in mouse embryos. Our results demonstrate the utility of these novel pattern detection strategies, notably for detection of periodic profiles, and suggest that combining several distinct mathematical approaches to analyze microarray datasets is a valuable strategy for identifying genes that exhibit novel, interesting transcriptional patterns.

Response Properties of the Auditory Telencephalon in Songbirds Change with Recent Experience and Season:

The caudomedial nidopallium (NCM) is a telencephalic auditory area that is selectively activated by conspecific vocalizations in zebra finches and canaries. We recently demonstrated that temporal and spectral dynamics of auditory tuning in NCM differ between these species [1]. In order to determine whether these differences reflect recent experience, we exposed separate groups of each species and sex to different housing conditions. Adult birds were housed either in an aviary with conspecifics (NORM), with heterospecifics (canary subjects in a zebra finch aviary, and vice versa: (CROSS)), or in isolation (ISO) for 9 days prior to testing. We then recorded extracellular multi-unit electrophysiological responses to simple pure tone stimuli (250-5000 Hz) in awake birds from each group and analyzed auditory tuning width using methods from our earlier studies. Relative to NORM birds, tuning was narrower in CROSS birds, and wider in ISO birds. The trend was greater in canaries, especially females. The date of recording was also included as a covariate in ANCOVAs that analyzed a larger set of the canary data, including data from birds tested outside of the breeding season, and treated housing condition and sex as independent variables. These tests show that tuning width was narrower early in the year and broader later. This effect was most pronounced in CROSS males. The degree of the short-term neural plasticity described here differs across sexes and species, and may reflect differences in NCM’s anatomical and functional organization related to species differences in song characteristics, adult plasticity and/or social factors. More generally, NCM tuning is labile and may be modulated by recent experience to reflect the auditory processing required for behavioral adaptation to the current acoustic, social or seasonal context.

Consumption of Bt Maize Pollen Expressing Cry1Ab or Cry3Bb1 Does Not Harm Adult Green Lacewings, Chrysoperla carnea (Neuroptera: Chrysopidae):

Adults of the common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), are prevalent pollen-consumers in maize fields. They are therefore exposed to insecticidal proteins expressed in the pollen of insect-resistant, genetically engineered maize varieties expressing Cry proteins derived from Bacillus thuringiensis (Bt). Laboratory experiments were conducted to evaluate the impact of Cry3Bb1 or Cry1Ab-expressing transgenic maize (MON 88017, Event Bt176) pollen on fitness parameters of adult C. carnea. Adults were fed pollen from Bt maize varieties or their corresponding near isolines together with sucrose solution for 28 days. Survival, pre-oviposition period, fecundity, fertility and dry weight were not different between Bt or non-Bt maize pollen treatments. In order to ensure that adults of C. carnea are not sensitive to the tested toxins independent from the plant background and to add certainty to the hazard assessment, adult C. carnea were fed with artificial diet containing purified Cry3Bb1 or Cry1Ab at about a 10 times higher concentration than in maize pollen. Artificial diet containing Galanthus nivalis agglutinin (GNA) was included as a positive control. No differences were found in any life-table parameter between Cry protein containing diet treatments and control diet. However, the pre-oviposition period, daily and total fecundity and dry weight of C. carnea were significantly negatively affected by GNA-feeding. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources as well as the uptake by C. carnea was confirmed. These results show that adults of C. carnea are not affected by Bt maize pollen and are not sensitive to Cry1Ab and Cry3Bb1 at concentrations exceeding the levels in pollen. Consequently, Bt maize pollen consumption will pose a negligible risk to adult C. carnea.

Three-Dimensional Analysis of Vascular Development in the Mouse Embryo:

Key vasculogenic (de-novo vessel forming) and angiogenic (vessel remodelling) events occur in the mouse embryo between embryonic days (E) 8.0 and 10.0 of gestation, during which time the vasculature develops from a simple circulatory loop into a complex, fine structured, three-dimensional organ. Interpretation of vascular phenotypes exhibited by signalling pathway mutants has historically been hindered by an inability to comprehensively image the normal sequence of events that shape the basic architecture of the early mouse vascular system. We have employed Optical Projection Tomography (OPT) using frequency distance relationship (FDR)-based deconvolution to image embryos immunostained with the endothelial specific marker PECAM-1 to create a high resolution, three-dimensional atlas of mouse vascular development between E8.0 and E10.0 (5 to 30 somites). Analysis of the atlas has provided significant new information regarding normal development of intersomitic vessels, the perineural vascular plexus, the cephalic plexus and vessels connecting the embryonic and extraembryonic circulation. We describe examples of vascular remodelling that provide new insight into the mechanisms of sprouting angiogenesis, vascular guidance cues and artery/vein identity that directly relate to phenotypes observed in mouse mutants affecting vascular development between E8.0 and E10.0. This atlas is freely available at http://www.mouseimaging.ca/research/mouse_atlas.html and will serve as a platform to provide insight into normal and abnormal vascular development.

Characterization of a Nonclassical Class I MHC Gene in a Reptile, the Galápagos Marine Iguana (Amblyrhynchus cristatus):

Squamates are a diverse order of vertebrates, representing more than 7,000 species. Yet, descriptions of full-length major histocompatibility complex (MHC) genes in this group are nearly absent from the literature, while the number of MHC studies continues to rise in other vertebrate taxa. The lack of basic information about MHC organization in squamates inhibits investigation into the relationship between MHC polymorphism and disease, and leaves a large taxonomic gap in our understanding of amniote MHC evolution. Here, we use both cDNA and genomic sequence data to characterize a class I MHC gene (Amcr-UA) from the Galápagos marine iguana, a member of the squamate subfamily Iguaninae. Amcr-UA appears to be functional since it is expressed in the blood and contains many of the conserved peptide-binding residues that are found in classical class I genes of other vertebrates. In addition, comparison of Amcr-UA to homologous sequences from other iguanine species shows that the antigen-binding portion of this gene is under purifying selection, rather than balancing selection, and therefore may have a conserved function. A striking feature of Amcr-UA is that both the cDNA and genomic sequences lack the transmembrane and cytoplasmic domains that are necessary to anchor the class I receptor molecule into the cell membrane, suggesting that the product of this gene is secreted and consequently not involved in classical class I antigen-presentation. The truncated and conserved character of Amcr-UA lead us to define it as a nonclassical gene that is related to the few available squamate class I sequences. However, phylogenetic analysis placed Amcr-UA in a basal position relative to other published classical MHC genes from squamates, suggesting that this gene diverged near the beginning of squamate diversification.

More….

Continue reading →

Novel Kind Of Learning Gene Discovered:

Scientists at the Freie Universität Berlin have come one step closer to unraveling the molecular basis of learning. A team led by neurobiologist Björn Brembs has discovered the first gene for operant conditioning in the fruit fly Drosophila.

Family Type Has Less-than-expected Impact On Parental Involvement, Study Finds:

Children in step-families and in other non-traditional families get just as much quality time with their parents as those in traditional families, with only a few exceptions, according to research to be presented at the annual meeting of the American Sociological Association today.

Homeownership In Disadvantaged Neighborhoods Linked To Increased Political Participation:

Homeowners in disadvantaged neighborhoods are more likely to vote than renters and those who own homes in more privileged communities, according to research to be presented at the annual meeting of the American Sociological Association (ASA).

Teacher-student Relationships Key To Learning Health And Sex Education:

When it comes to learning life-changing behaviors in high school health classes, the identity of the person teaching may be even more important than the curriculum, a new study suggests.

Paradox Of Higher Education, Crime: Male College Students More Likely Than Less-educated Peers To Commit Property Crimes, Study Finds:

Men who attend college are more likely to commit property crimes during their college years than their non-college-attending peers, according to research to be presented at the annual meeting of the American Sociological Association.

New Role Found For A ‘Foxy Old Gene’:

Researchers at the University of Pennsylvania School of Medicine have discovered that a protein called FOXA2 controls genes that maintain the proper level of bile in the liver. FOXA2 may become the focus for new therapies to treat diseases that involve the regulation of bile salts. The study was published online this week in Nature Medicine.

Extinction Threat To Monkeys And Other Primates Due To Habitat Loss, Hunting:

Mankind’s closest relatives – the world’s monkeys, apes and other primates – are disappearing from the face of the Earth, with some literally being eaten into extinction.

Memory, Depression, Insomnia — And Worms?:

Researchers have spent decades probing the causes of depression, schizophrenia and insomnia in humans. But a new study may have uncovered key insights into the origins of these and other conditions by examining a most unlikely research subject: worms.

Little Teeth Suggest Big Jump In Primate Timeline:

Tiny fossilized teeth excavated from an Indian open-pit coal mine could be the oldest Asian remains ever found of anthropoids, the primate lineage of today’s monkeys, apes and humans, say researchers from Duke University and the Indian Institute of Technology.

It’s Monday afternoon, time to take a look at the brand new articles in PLoS Medicine and PLoS Biology:
Tasting the Bitter Sunlight:

Have you ever had that gut reaction to your surroundings, some physical sensation that something isn’t quite right? Maybe a squirmy, uneasy feeling in your stomach or an acrid taste on your tongue that makes you want to leave the scene? When the nematode C. elegans encounters an offensive sensation–whether a pungent, potentially dangerous odor (such as those associated with fungal parasites), extreme temperature, or the poking probe of a researcher–it wastes no time in making a hasty retreat. Researchers have elucidated the mechanisms of avoidance in these tiny worms to remarkable molecular and cellular detail (a much clearer picture than the often mysterious avoidance behaviors of humans).
In a new study, Stacey L. Edwards, Kenneth G. Miller, and colleagues expand the level of our understanding by describing a striking new behavior and mechanism of sensory detection for these microscopic animals. They demonstrate that short-wavelength light, such as blue-violet and ultraviolet (UV), is a potent avoidance cue, stimulating a robust acceleration of locomotion when the tail or body is illuminated, while head illumination drives reversal locomotion. After identifying and characterizing this new behavior, Edwards et al. used classic forward genetics (whereby animals are mutagenized and screened for defective phenotypes) to identify mutants that are unresponsive to UV light. Surprisingly, the mutations mapped to a gene that encodes a protein unrelated to any of the known phototransduction systems in nature. The authors named this new protein LITE-1 and showed that it functions as a UV light receptor. Interestingly, LITE-1 is related to the large family of insect Gustatory receptors that mediate taste responses. The closest homology is to that of fly Gustatory receptors, which detect water-soluble sugars and carbon dioxide.

Can a Topical Microbicide Prevent Rectal HIV Transmission?:

Animal models are critical tools for the preclinical evaluation of drugs. Yet in the HIV field, the value of such models for predicting the success of preventive drug and vaccination strategies in humans has been disappointing. For example, animal models were unable to predict the failure of vaginal microbicides in large clinical trials in humans [1,2]. However, two recently published studies have provided encouraging results. Using a repeat, low-dose exposure macaque model, Walid Heneine and colleagues found that systemic pre-exposure prophylaxis (PrEP), using a combination of the nucleoside analogue reverse transcriptase inhibitors emtricitabine and tenofovir, protected macaques against rectal challenge with simian HIV [3]. Most prior macaque studies used single high-dose virus challenges, which are less representative of viral exposure in humans. Another study by J. Victor Garcia and colleagues introduced an improved mouse model of vaginal HIV transmission [4]. Mice engineered to stably exhibit extensive infiltration of organs and tissues, including the female reproductive tract, with a broad range of human blood cells were protected from intravaginal HIV infection by PrEP with emtricitabine/tenofovir. This mouse model opened the way for larger-scale comparative assessments in vivo, which is impossible in macaques due to the prohibitively high costs.
A third key study by Martin Cranage and colleagues is published in this issue of PLoS Medicine [5]. The researchers investigated whether rectal simian immunodeficiency virus (SIV) transmission in macaques could be prevented by the topical pre-exposure application of tenofovir gel. Rectal SIV or HIV challenge bears a much higher transmission probability than vaginal challenge. With some caveats, as discussed further below, successful prevention of rectal transmission is therefore likely to have a better predictive value for human trials than vaginal challenge models. Moreover, anal intercourse in heterosexual populations has been underestimated in the past, and means to prevent rectal HIV transmission are thus urgently needed for both women and men who have unprotected anal intercourse.

Sleep Apnea Linked To Increased Risk Of Death:

Sleep-disordered breathing (also known as sleep apnea) is associated with an increased risk of death, according to new results from the Wisconsin Sleep Cohort, an 18-year observational study supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.

World’s Smallest Snake Found In Barbados:

The world’s smallest species of snake, with adults averaging just under four inches in length, has been identified on the Caribbean island of Barbados. The species — which is as thin as a spaghetti noodle and small enough to rest comfortably on a U.S. quarter –was discovered by Blair Hedges, an evolutionary biologist at Penn State.

Long Work Hours Widen The Gender Gap:

Working overtime has a disproportionate impact on women in dual-earner households, exacerbating gender inequality and supporting the “separate sphere” phenomenon in which men are the breadwinners while women tend to the home, according to research to be presented at the annual meeting of the American Sociological Association.

Australian Bird Research Could Rewrite ‘Ring Theory’ Of Speciation:

New research has uncovered how different populations of the bird crimson rosella are related to each other – a discovery which has important implications for research into how climate change may affect Australia’s biodiversity.

Plant Parasite ‘Wiretaps’ Host:

A parasitic plant that sucks water and nutrients from its plant host also taps into its communications traffic, a new report finds. The research could lead to new ways to combat parasites that attack crop plants.

Fungi Expert Finds New Species In Aberdeen City Centre, Scotland:

A leading fungi expert has accidentally stumbled upon a new species in Scotland – as he walked home from work.

Cellular Symmetry: What Cues Tell A Cell To Divide At The Center:

Cells are intrinsically artistic. When the right signals tell a cell to divide, it usually splits down the middle, resulting in two identical daughter cells. (Stem cells are the exception to the rule.) This natural symmetry is visible on the macroscopic scale as well. All living creatures, be they mushrooms or humans, are visibly symmetric, a product of our cells’ preference for equilibrium.

Emerging Scientific Discipline Of Aeroecology:

Aeroecology is the emerging discipline for studying how airborne organisms — birds, bats, arthropods and microbes — depend on the support of the lower atmosphere that is closest to the Earth’s surface.

Fruit-fly Study Adds Weight To Theories About Another Type Of Adult Stem Cell:

It turns out that an old dog – or at least an old fruit-fly cell – can learn new tricks. Researchers at the Stanford University School of Medicine have found that mature, specialized cells naturally regress to serve as a kind of de facto stem cell during the fruit-fly life cycle.

Brain Plays Key Role In Appetite By Regulating Free Radicals:

Researchers at Yale School of Medicine have found the brain’s appetite center uses fat for fuel by involving oxygen free radicals–molecules associated with aging and neurodegeneration. The findings, reported in the journal Nature, suggest that antioxidants could play a role in weight control.

How ‘Hidden Mutations’ Contribute To HIV Drug Resistance:

One of the major reasons that treatment for HIV/AIDS often doesn’t work as well as it should is resistance to the drugs involved. Now, scientists at McGill University have revealed how mutations hidden in previously ignored parts of the HIV genome play an important role in the development of drug resistance in AIDS patients.

The Power Of Peter Piper: How Alliteration Enhances Poetry, Prose, And Memory:

From nursery rhymes to Shakespearian sonnets, alliterations have always been an important aspect of poetry whether as an interesting aesthetic touch or just as something fun to read. But a recent study suggests that this literary technique is useful not only for poetry but also for memory.

Evolution Of Skull And Mandible Shape In Cats:

In a new study published in the online-open access journal PLoS ONE, Per Christiansen at the Zoological Museum in Copenhagen, Denmark, reports the finding that the evolution of skull and mandible shape in sabercats and modern cats were governed by different selective forces, and the two groups evolved very different adaptations to killing.

Newly Discovered Monkey Is Threatened With Extinction:

Just three years after it was discovered, a new species of monkey is threatened with extinction according to the Wildlife Conservation Society, which recently published the first-ever census of the endangered primate. Known as the “kipunji,” the large, forest-dwelling primate hovers at 1,117 individuals, according to a study released in the July issue of the journal Oryx.

Virus Behind Mysterious Parrot Disease Identified:

Researchers at the University of California, San Francisco, have identified a virus behind the mysterious infectious disease that has been killing parrots and exotic birds for more than 30 years.

Brain Tweak Lets Sleep-deprived Flies Stay Sharp:

Staying awake slows down our brains, scientists have long recognized. Mental performance is at its peak after sleep but inevitably trends downward throughout the day, and sleep deprivation only worsens these effects.

Aging Impairs The ‘Replay’ Of Memories During Sleep:

Aging impairs the consolidation of memories during sleep, a process important in converting new memories into long-term ones, according to new animal research in the July 30 issue of The Journal of Neuroscience. The findings shed light on normal memory mechanisms and how they are disrupted by aging.

Biological Fathers Not Necessarily The Best, Social Dads Parent Well Too:

A large number of U.S. children live or will live with a “social father,” a man who is married to or cohabiting with the child’s mother, but is not the biological father.

Continue reading →

So, let’s see what’s new in PLoS Genetics, PLoS Computational Biology, PLoS Pathogens and PLoS Neglected Tropical Diseases this week. 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:
Patterns of Positive Selection in Six Mammalian Genomes:

Populations evolve as mutations arise in individual organisms and, through hereditary transmission, gradually become “fixed” (shared by all individuals) in the population. Many mutations have essentially no effect on organismal fitness and can become fixed only by the stochastic process of neutral drift. However, some mutations produce a selective advantage that boosts their chances of reaching fixation. Genes in which new mutations tend to be beneficial, rather than neutral or deleterious, tend to evolve rapidly and are said to be under positive selection. Genes involved in immunity and defense are a well-known example; rapid evolution in these genes presumably occurs because new mutations help organisms to prevail in evolutionary “arms races” with pathogens. Many mammalian genes show evidence of positive selection, but open questions remain about the overall impact of positive selection in mammals. For example, which key differences between species can be attributed to positive selection? How have patterns of selection changed across the mammalian phylogeny? What are the effects of population size and gene expression patterns on positive selection? Here we attempt to shed light on these and other questions in a comprehensive study of ~16,500 genes in six mammalian genomes.

Engaging the Community: An Interview with Uche Amazigo:

Walking purposefully towards the shabby grey concrete structure that functions as the main health centre of Kyenjojo district in western Uganda, public health doctor Andrew Byamungu makes a trip he has done many times before since joining the vector control department of the Ugandan Ministry of Health. Fighting his way through the crowds of waiting patients and relatives, he greets the tired-looking health staff who, among their many other duties, are responsible for education and drug distribution in the country’s onchocerciasis control programme, which is one of the most advanced of the 19 country projects of the African Programme for Onchocerciasis Control (APOC).

H5N1 and 1918 Pandemic Influenza Virus Infection Results in Early and Excessive Infiltration of Macrophages and Neutrophils in the Lungs of Mice:

Patients who succumbed to influenza during the pandemic from 1918 to 1919 had severe lung pathology marked by extensive inflammatory infiltrate, indicating a robust immune response in the lung. Similar findings have been reported from H5N1-infected patients, raising the question as to why people expire in the presence of a strong immune response. We addressed this question by characterizing the immune cell populations in the mouse lung following infection with the 1918 pandemic virus and two H5N1 viruses isolated from fatal cases. We found that certain cells of the innate immune system, specifically macrophages and neutrophils, increase significantly early during infection but that the cells responsible for bridging the innate and adaptive immune responses, dendritic cells and the orchestrators of viral clearance, T cells, did not differ significantly between infection groups. Dendritic cells and mouse lung macrophages were shown to be susceptible to 1918 and H5N1 virus infection in vitro, suggesting a possible mechanism of pathogenesis. Our data shows excessive immune cell infiltration in the lungs contributing to severe consolidation and tissue architecture destruction in mice infected with highly pathogenic influenza viruses, supporting the histopathological observations of lung tissue from 1918 and H5N1 fatalities. Identification of the precise inflammatory cells associated with lung inflammation will be important for the development of treatments that could potentially enhance or modulate host innate immune responses.

Rise of the Machines:

Until recently, sequencing the entire genome of an organism was a major endeavor. New technologies are transforming this task into routine practice and launching a new assault on whole-genome sequencing.
It is more than 30 years since Sir Fred Sanger and colleagues published their method for sequencing DNA [1]. This Nobel Prize-winning work formed the basis of the vast majority of subsequent sequencing methodologies, albeit with some crucial technical innovations. Despite the great utility of Sanger sequencing, its scalability is inherently limited, and therefore the creation of warehouse-sized facilities was required to accomplish whole-genome sequencing projects. As a result, sequencing more than a few kilobases of DNA–a requirement for all but the simplest genomes–has long remained the province of a few dedicated sequencing centers. Within the last year, however, things have begun to change in dramatic ways. New sequencing technologies are emerging, announced in an assortment of reports, conference presentations, and press releases. In this issue of PLoS Genetics, Srivatsan et al. [2] report the resequencing of several genomes of the bacterium Bacillus subtilis using one of these new technologies. A new battle at the frontier of DNA sequencing has commenced.

A Model of Stimulus-Specific Neural Assemblies in the Insect Antennal Lobe:

It has been proposed that synchronized neural assemblies in the antennal lobe of insects encode the identity of olfactory stimuli. In response to an odor, some projection neurons exhibit synchronous firing, phase-locked to the oscillations of the field potential, whereas others do not. Experimental data indicate that neural synchronization and field oscillations are induced by fast GABAA-type inhibition, but it remains unclear how desynchronization occurs. We hypothesize that slow inhibition plays a key role in desynchronizing projection neurons. Because synaptic noise is believed to be the dominant factor that limits neuronal reliability, we consider a computational model of the antennal lobe in which a population of oscillatory neurons interact through unreliable GABAA and GABAB inhibitory synapses. From theoretical analysis and extensive computer simulations, we show that transmission failures at slow GABAB synapses make the neural response unpredictable. Depending on the balance between GABAA and GABAB inputs, particular neurons may either synchronize or desynchronize. These findings suggest a wiring scheme that triggers stimulus-specific synchronized assemblies. Inhibitory connections are set by Hebbian learning and selectively activated by stimulus patterns to form a spiking associative memory whose storage capacity is comparable to that of classical binary-coded models. We conclude that fast inhibition acts in concert with slow inhibition to reformat the glomerular input into odor-specific synchronized neural assemblies.

High-Precision, Whole-Genome Sequencing of Laboratory Strains Facilitates Genetic Studies:

In this manuscript, we describe novel applications of the newly developed Solexa sequencing technology. We aim to provide insights into the following questions: (1) Can whole-genome sequencing, while rapidly surveying mega-bases of genome information, also reliably identify variations at the base-pair resolution? (2) Can it be used to identify the differences between isolates of the same laboratory strain and between different laboratory strains? (3) Can it be used as a genetic tool to predict phenotypes and identify suppressors? To this end, we performed whole-genome shotgun sequencing of several related strains of the widely studied model bacterium Bacillus subtilis, we identified genomic variations that potentially underlie strain-specific phenotypes, which occur frequently in biological studies, and we found multiple suppressor mutations within a single strain that are difficult to discern through traditional methods. We conclude that whole-genome sequencing can be directly used to guide genetic studies.

Searching For Shut Eye: Possible ‘Sleep Gene’ Identified:

While scientists and physicians know what happens if you don’t get six to eight hours of shut-eye a night, investigators have long been puzzled about what controls the actual need for sleep. Researchers at the University of Pennsylvania School of Medicine might have an answer, at least in fruit flies. In a recent study of fruit flies, they identified a gene that controls sleep.

Did Dinosaur Soft Tissues Still Survive? New Research Challenges Notion:

Paleontologists in 2005 hailed research that apparently showed that soft, pliable tissues had been recovered from dissolved dinosaur bones, a major finding that would substantially widen the known range of preserved biomolecules.

Lost An Appendage? Grow Another:

Cut off one finger from a salamander and one will grow back. Cut off two and two will grow back. It sounds logical, but how the salamander always regenerates the right number of fingers is still a biological mystery.

Fertility: Newly Discovered Proteins In Seminal Fluid Transferred During Mating May Affect Odds Of Producing Offspring:

Seminal fluid contains protein factors that, when transferred from a male to a female at mating, affect reproductive success. This is true of many different animals, from crickets to primates.

European Birds Flock To Warming Britain, While Some Northern Species Not Faring As Well:

Researchers at Durham, the RSPB and Cambridge University have found that birds such as the Cirl Bunting and Dartford Warbler are becoming more common across a wide range of habitats in Britain as temperatures rise.

The Buzz Of The Chase: Scientists Test Technique Used To Catch Serial Killers … On Bumblebees:

Scientists from Queen Mary, University of London are helping to perfect a technique used to catch serial killers, by testing it on bumblebees.

‘Chicken And Chips’ Theory Of Pacific Migration:

A new study of DNA from ancient and modern chickens has shed light on the controversy about the extent of pre-historic Polynesian contact with the Americas.

Life In A Bubble: Mathematicians Explain How Insects Breathe Underwater:

Hundreds of insect species spend much of their time underwater, where food may be more plentiful. MIT mathematicians have now figured out exactly how those insects breathe underwater.

Olfactory Fine-tuning Helps Fruit Flies Find Their Mates:

Fruit flies fine-tune their olfactory systems by recalibrating the sensitivity of different odor channels in response to changing concentrations of environmental cues, a new study has shown. Disable this calibration system, and flies have trouble finding a mate, the researchers found.

There are 62 new articles in PLoS ONE this week. 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:
Diurnal and Circadian Rhythms in the Tomato Transcriptome and Their Modulation by Cryptochrome Photoreceptors:

Circadian clocks are internal molecular time-keeping mechanisms that provide living organisms with the ability to adjust their growth and physiology and to anticipate diurnal environmental changes. Circadian clocks, without exception, respond to light and, in plants, light is the most potent and best characterized entraining stimulus. The capacity of plants to respond to light is achieved through a number of photo-perceptive proteins including cryptochromes and phytochromes. There is considerable experimental evidence demonstrating the roles of photoreceptors in providing light input to the clock. In order to identify genes regulated by diurnal and circadian rhythms, and to establish possible functional relations between photoreceptors and the circadian clock in tomato, we monitored the temporal transcription pattern in plants entrained to long-day conditions, either by large scale comparative profiling, or using a focused approach over a number of photosensory and clock-related genes by QRT-PCR. In parallel, focused transcription analyses were performed in cry1a- and in CRY2-OX tomato genotypes. We report a large series of transcript oscillations that shed light on the complex network of interactions among tomato photoreceptors and clock-related genes. Alteration of cryptochrome gene expression induced major changes in the rhythmic oscillations of several other gene transcripts. In particular, over-expression of CRY2 had an impact not only on day/night fluctuations but also on rhythmicity under constant light conditions. Evidence was found for widespread diurnal oscillations of transcripts encoding specific enzyme classes (e.g. carotenoid biosynthesis enzymes) as well as for post-transcriptional diurnal and circadian regulation of the CRY2 transcript.

Postglacial Colonisation Patterns and the Role of Isolation and Expansion in Driving Diversification in a Passerine Bird:

Pleistocene glacial cycles play a major role in diversification and speciation, although the relative importance of isolation and expansion in driving diversification remains debated. We analysed mitochondrial DNA sequence data from 15 great reed warbler (Acrocephalus arundinaceus) populations distributed over the vast Eurasian breeding range of the species, and revealed unexpected postglacial expansion patterns from two glacial refugia. There were 58 different haplotypes forming two major clades, A and B. Clade A dominated in Western Europe with declining frequencies towards Eastern Europe and the Middle East, but showed a surprising increase in frequency in Western and Central Asia. Clade B dominated in the Middle East, with declining frequencies towards north in Central and Eastern Europe and was absent from Western Europe and Central Asia. A parsimonious explanation for these patterns is independent postglacial expansions from two isolated refugia, and mismatch distribution analyses confirmed this suggestion. Gene flow analyses showed that clade A colonised both Europe and Asia from a refugium in Europe, and that clade B expanded much later and colonised parts of Europe from a refugium in the Middle East. Great reed warblers in the eastern parts of the range have slightly paler plumage than western birds (sometimes treated as separate subspecies; A. a. zarudnyi and A. a. arundinaceus, respectively) and our results suggest that the plumage diversification took place during the easterly expansion of clade A. This supports the postglacial expansion hypothesis proposing that postglacial expansions drive diversification in comparatively short time periods. However, there is no indication of any (strong) reproductive isolation between clades and our data show that the refugia populations became separated during the last glaciation. This is in line with the Pleistocene speciation hypothesis invoking that much longer periods of time in isolation are needed for speciation to occur.

Evolution of Skull and Mandible Shape in Cats (Carnivora: Felidae):

The felid family consists of two major subgroups, the sabretoothed and the feline cats, to which all extant species belong, and are the most anatomically derived of all carnivores for predation on large prey with a precision killing bite. There has been much controversy and uncertainty about why the skulls and mandibles of sabretoothed and feline cats evolved to become so anatomically divergent, but previous models have focused on single characters and no unifying hypothesis of evolutionary shape changes has been formulated. Here I show that the shape of the skull and mandible in derived sabrecats occupy entirely different positions within overall morphospace from feline cats, and that the evolution of skull and mandible shape has followed very different paths in the two subgroups. When normalised for body-size differences, evolution of bite forces differ markedly in the two groups, and are much lower in derived sabrecats, and they show a significant relationship with size and cranial shape, whereas no such relationship is present in feline cats. Evolution of skull and mandible shape in modern cats has been governed by the need for uniform powerful biting irrespective of body size, whereas in sabrecats, shape evolution was governed by selective pressures for efficient predation with hypertrophied upper canines at high gape angles, and bite forces were secondary and became progressively weaker during sabrecat evolution. The current study emphasises combinations of new techniques for morphological shape analysis and biomechanical studies to formulate evolutionary hypotheses for difficult groups.

Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms:

A scanning electron microscope survey was initiated to determine if the previously reported findings of “dinosaurian soft tissues” could be identified in situ within the bones. The results obtained allowed a reinterpretation of the formation and preservation of several types of these “tissues” and their content. Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time. They represent bacterial biofilms common throughout nature. Biofilms form endocasts and once dissolved out of the bone, mimic real blood vessels and osteocytes. Bridged trails observed in biofilms indicate that a previously viscous film was populated with swimming bacteria. Carbon dating of the film points to its relatively modern origin. A comparison of infrared spectra of modern biofilms with modern collagen and fossil bone coatings suggests that modern biofilms share a closer molecular make-up than modern collagen to the coatings from fossil bones. Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids. Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

From Plants to Birds: Higher Avian Predation Rates in Trees Responding to Insect Herbivory:

An understanding of the evolution of potential signals from plants to the predators of their herbivores may provide exciting examples of co-evolution among multiple trophic levels. Understanding the mechanism behind the attraction of predators to plants is crucial to conclusions about co-evolution. For example, insectivorous birds are attracted to herbivore-damaged trees without seeing the herbivores or the defoliated parts, but it is not known whether birds use cues from herbivore-damaged plants with a specific adaptation of plants for this purpose. We examined whether signals from damaged trees attract avian predators in the wild and whether birds could use volatile organic compound (VOC) emissions or net photosynthesis of leaves as cues to detect herbivore-rich trees. We conducted a field experiment with mountain birches (Betula pubescens ssp. czerepanovii), their main herbivore (Epirrita autumnata) and insectivorous birds. Half of the trees had herbivore larvae defoliating trees hidden inside branch bags and half had empty bags as controls. We measured predation rate of birds towards artificial larvae on tree branches, and VOC emissions and net photosynthesis of leaves. The predation rate was higher in the herbivore trees than in the control trees. This confirms that birds use cues from trees to locate insect-rich trees in the wild. The herbivore trees had decreased photosynthesis and elevated emissions of many VOCs, which suggests that birds could use either one, or both, as cues. There was, however, large variation in how the VOC emission correlated with predation rate. Emissions of (E)-DMNT [(E)-4,8-dimethyl-1,3,7-nonatriene], β-ocimene and linalool were positively correlated with predation rate, while those of highly inducible green leaf volatiles were not. These three VOCs are also involved in the attraction of insect parasitoids and predatory mites to herbivore-damaged plants, which suggests that plants may not have specific adaptations to signal only to birds.

Temperature-Dependent Sex Determination in Fish Revisited: Prevalence, a Single Sex Ratio Response Pattern, and Possible Effects of Climate Change:

In gonochoristic vertebrates, sex determination mechanisms can be classified as genotypic (GSD) or temperature-dependent (TSD). Some cases of TSD in fish have been questioned, but the prevalent view is that TSD is very common in this group of animals, with three different response patterns to temperature. We analyzed field and laboratory data for the 59 fish species where TSD has been explicitly or implicitly claimed so far. For each species, we compiled data on the presence or absence of sex chromosomes and determined if the sex ratio response was obtained within temperatures that the species experiences in the wild. If so, we studied whether this response was statistically significant. We found evidence that many cases of observed sex ratio shifts in response to temperature reveal thermal alterations of an otherwise predominately GSD mechanism rather than the presence of TSD. We also show that in those fish species that actually have TSD, sex ratio response to increasing temperatures invariably results in highly male-biased sex ratios, and that even small changes of just 1-2°C can significantly alter the sex ratio from 1:1 (males:females) up to 3:1 in both freshwater and marine species. We demonstrate that TSD in fish is far less widespread than currently believed, suggesting that TSD is clearly the exception in fish sex determination. Further, species with TSD exhibit only one general sex ratio response pattern to temperature. However, the viability of some fish populations with TSD can be compromised through alterations in their sex ratios as a response to temperature fluctuations of the magnitude predicted by climate change.

And more:

Continue reading →

Piecing Together An Extinct Lemur, Large As A Big Baboon:

Penn State researchers have used computed tomography (CT) technology to virtually glue newly-discovered skull fragments of a rare extinct lemur back into its partial skull, which was discovered over a century ago. Alan Walker, Evan Pugh Professor of Anthropology and Biology at Penn State, and Research Associate in Anthropology Timothy Ryan, led the research. The different fragments of this lemur’s skull are separated by thousands of miles, with the partial skull in Vienna and the pieces of frontal bone in the United States.

Insect Biodiversity In Amazon May Be Result Of Ice Age Climate Change And Ancient Flooding, Not River Barriers:

Ice age climate change and ancient flooding–but not barriers created by rivers–may have promoted the evolution of new insect species in the Amazon region of South America, a new study suggests.

Unexpected Key To Flowering Plants’ Diversity:

What began with an off-the-cuff curiosity eventually led Joe Williams to hang from the limbs of a tree 80 feet above the soil of northeastern Australia. The things Williams, a University of Tennessee, Knoxville, researcher found there may help explain the amazing diversity in the world’s flowering plants, a question that has puzzled scientists from the time of Charles Darwin to today.

Uncertain Future For Elephants Of Thailand:

Worries over the future of Thailand’ s famous elephants have emerged following an investigation by a University of Manchester team.

Endangered European Wild Cat May Protected By Proposed Network Of Corridors:

For the first time an international researcher team has developed a model, which identifies potential habitats and corridors for the European wildcat (Felis silvestris silvestris). Using Rheinland-Pfalz as an example, it was demonstrated that almost half of this German federal state could be suitable for wildcats, enabling a maximum population of 1600 females.

What’s new in PLoS Biology and PLoS Medicine this week? Among else:

Continue reading →

Birdsong Not Just For The Birds: Bio-acoustic Method Also Hears Nature’s Cry For Help:

Switch on the mike, start the recording, the stage is set for the local fauna!

Explosion In Marine Biodiversity Explained By Climate Change:

A global change in climate could explain the explosion in marine biodiversity that took place 460 million years ago. Researchers from Lyon (1) and Canberra (Australia) (2) have found evidence of a progressive ocean cooling of about 15°C over a period of 40 million years during the Ordovician (3). Until now, this geologic period had been associated with a “super greenhouse effect” on our planet.

Plant Steroids Offer New Paradigm For How Hormones Work:

Steroids bulk up plants just as they do human athletes, but the playbook of molecular signals that tell the genes to boost growth and development in plant cells is far more complicated than in human and animal cells.

Acidification Of The Sea Hampers Reproduction Of Marine Species: Decreasing pH The Biggest Threat To Marine Animal Life For Thousands Of Years:

By absorbing carbon dioxide from the atmosphere, and from the human use of fossil fuels, the world’s seas function as a giant buffer for the Earth’s life support system. The chemical balance of the sea has long been regarded as immovable.

Bacteria Reveal Secret Of Adaptation At Evolution Canyon:

Bacteria living on opposite sides of a canyon have evolved to cope with different temperatures by altering the make-up of their ‘skin’, or cell membranes. Scientists have found that bacteria change these complex and important structures to adapt to different temperatures by looking at the appearance of the bacteria as well as their genes. The researchers hope their study, published in the August issue of Microbiology, will start a new trend in research.

Diversity In Primary Schools Promotes Harmony, Study Finds:

For the first time, children as young as 5 have been shown to understand issues regarding integration and separation. The research confirms that the ethnic composition of primary schools has a direct impact on children’s attitudes towards those in other ethnic groups and on their ability to get on with their peers.

Who’s More Likely To Do Sports? White, Middle Class, And Middle-aged:

The comfortably off, white, and middle aged are the most likely to participate in sporting activities, reveals a 10 year study published ahead of print in the British Journal of Sports Medicine.

Older People May Need Less Sleep, Study Finds:

Along with all the other changes that come with age, healthy older people also lose some capacity for sleep, according to a new report published online on July 24th in Current Biology. When asked to stay in bed for 16 hours in the dark each day for several days, younger people get an average of 9 hours of shuteye compared to 7.5 for older people, the researchers report.

Frequent Family Meals Might Reduce Teen Substance Use:

Parents who have regular meals with their adolescent children might help lessen the chances they will start drinking or smoking later in their teen years, according to new research.

Energy Drinks Linked To Risk-taking Behaviors Among College Students:

Over the last decade, energy drinks — such as Red Bull, Monster and Rockstar — have become nearly ubiquitous on college campuses. The global market for these types of drinks currently exceeds $3 billion a year and new products are introduced annually.

New Roadside Beautification Concept Studied:

Travel America’s highways or drive down any city street this summer and you’ll probably see them. From small, manicured beds of flowers maintained by community volunteers to extensive landscaping projects along America’s byways, roadside gardens are taking root.

Isolation-by-Distance and Outbreeding Depression Are Sufficient to Drive Parapatric Speciation in the Absence of Environmental Influences:

A commonly held view in evolutionary biology is that new species form in response to environmental factors, such as habitat differences or barriers to individual movements that sever a population. We have developed a computer model, called EvoSpace, that illustrates how new species can emerge when a species range becomes very large compared with the dispersal distances of its individuals. This situation has been called isolation-by-distance because remote parts of the range can take different evolutionary paths even though there is no particular place where we would expect different populations to separate. When the extent of genetic difference between individuals is coupled with decreasing offspring viability (e.g., resulting from developmental problems), EvoSpace predicts that sharp spatial boundaries can emerge in arbitrary locations, separating subpopulations that occasionally persist long enough to become reproductively incompatible species. The model shows an inherent tendency toward spatial self-organization, in contrast with the traditional view of environmentally forced origins of new species. We think that isolation-by-distance is a common aspect of the evolutionary process and that spatial self-organization of gene pools may often facilitate the evolution of new species.

The Interplay between Entamoeba and Enteropathogenic Bacteria Modulates Epithelial Cell Damage:

In amoebiasis, a human disease that is a serious health problem in many developing countries, efforts have been made to identify responsible factors for the tissue damage inflicted by the parasite Entamoeba histolytica. This amoeba lives in the lumen of the colon without causing damage to the intestinal mucosa, but under unknown circumstances becomes invasive, destroying the intestinal tissue. Bacteria in the intestinal flora have been proposed as inducers of higher amoebic virulence, but the causes or mechanisms responsible for the induction are still undetermined. Mixed intestinal infections with Entamoeba histolytica and enteropathogenic bacteria, showing exacerbated manifestations of disease, are common in endemic countries. We implemented an experimental system to study amoebic virulence in the presence of pathogenic bacteria and its consequences on epithelial cells. Results showed that amoebae that ingested enteropathogenic bacteria became more virulent, causing more damage to epithelial cells. Bacteria induced release of inflammatory proteins by the epithelial cells that attracted amoebae, facilitating amoebic contact to the epithelial cells and higher damage. Our results, although a first approach to this complex problem, provide insights into amoebic infections, as interplay with other pathogens apparently influences the intestinal environment, the behavior of cells involved and the manifestations of the disease.

‘Snow Flea Antifreeze Protein’ Could Help Improve Organ Preservation:

Scientists in Illinois and Pennsylvania are reporting development of a way to make the antifreeze protein that enables billions of Canadian snow fleas to survive frigid winter temperatures. Their laboratory-produced first-of-a-kind proteins could have practical uses in extending the storage life of donor organs and tissues for human transplantation, according to new research.

Freedom’s Just Another Word For Less Sexually Active Teens:

Sophisticated statistical research is providing more evidence of a link between rigid parenting and increased sexual activity in older teens. Although it is difficult to confirm that controlling mothers and fathers cause kids to have more sex, the findings suggest it is wise to give children freedom, said Rebekah Levine Coley, lead author of a new study of nearly 5,000 U.S. teenagers. Coley is an associate professor of applied developmental and educational psychology at Boston College.

Costs Of Climate Change, State-by-state: Billions, Says New Report:

Climate change will carry a price tag of billions of dollars for a number of U.S. states, says a new series of reports from the University of Maryland’s Center for Integrative Environmental Research (CIER). The researchers conclude that the costs have already begun to accrue and are likely to endure.

It Takes Nerves For Flies To Keep A Level Head:

The nerve connections that keep a fly’s gaze stable during complex aerial manoeuvres, enabling it to respond quickly to obstacles in its flight path, are revealed in new detail in research published today (22 July 2008).

Various Species’ Genes Evolve To Minimize Protein Production Errors:

Scientists at Harvard University and the University of Texas at Austin have found that genetic evolution is strongly shaped by genes’ efforts to prevent or tolerate errors in protein production.

Prevailing Theory Of Aging Challenged: Genetic Instructions Found To Drive Aging In Worms:

Age may not be rust after all. Specific genetic instructions drive aging in worms, report researchers at the Stanford University School of Medicine. Their discovery contradicts the prevailing theory that aging is a buildup of tissue damage akin to rust, and implies science might eventually halt or even reverse the ravages of age.

Outdoor Enthusiasts Scaring Off Native Carnivores In Parks:

Even a quiet stroll in the park can dramatically change natural ecosystems, according to a new study by conservation biologists from the University of California, Berkeley. These findings could have important implications for land management policies.

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.

What’s new in PLoS Computational Biology, PLoS Genetics, PLoS Pathogens and PLoS Neglected Tropical Diseases this week? Among else, these papers that caught my eye:
Emergent Synchronous Bursting of Oxytocin Neuronal Network:

When young suckle, they are rewarded intermittently with a let-down of milk that results from reflex secretion of the hormone oxytocin. Oxytocin is a neuropeptide made by specialised neurons in the hypothalamus, and is secreted from nerve endings in the pituitary gland. During suckling, every 5 min or so, each of these neurons discharges a brief, intense burst of action potentials; these are propagated down the axons, and release a pulse of oxytocin into the circulation. Here, we have built a computational model to understand how these bursts arise and how they are synchronized. In our model, bursting is an emergent behaviour of a complex system, involving both positive and negative feedbacks, between many, sparsely connected cells. The oxytocin cells are regulated by independent afferent inputs, but they interact by local release of oxytocin and endocannabinoids. Oxytocin released from the dendrites of these cells has a positive-feedback effect, while endocannabinoids have an inhibitory effect by suppressing the afferent input to the cells. Many neurons make peptides that act as messengers within the brain, and many of these are also released from dendrites, so this model may reflect a common pattern-generating mechanism in the brain.

Genome-Wide Expression Patterns and the Genetic Architecture of a Fundamental Social Trait:

Fundamental research goals for scientists interested in social evolution are to determine the numbers and types of genes that directly regulate individual social behaviors as well as to understand how the social environment indirectly influences the expression of socially relevant traits. The fire ant Solenopsis invicta features a remarkable form of social variation in which the occurrence of two distinct social types that differ in colony queen number is associated with genetic differences at a genomic region marked by the gene Gp-9. Our analyses of gene expression profiles in fire ant workers revealed that differences in Gp-9 genotype are associated with the differential expression of an unexpectedly small number of genes, many of which are predicted to function in chemical communication relevant to the regulation of colony queen number. Surprisingly, worker gene expression profiles are more strongly influenced by indirect effects associated with the social environment within their colony than by the direct effect of their own Gp-9 genotype. These results suggest a complex genetic architecture underlying the control of colony queen number in fire ants, with a single Mendelian factor directly regulating, and the social environment indirectly influencing, the expression of the individual behaviors that, in aggregate, yield an emergent colony social organization.

Tracking the Odysseys of Juvenile Schistosomes to Understand Host Interactions:

The prospects confronting a “new-born” schistosome cercaria are formidable. That some of these microscopic helminths successfully negotiate the tortuous route from snail to human vasculature is a truly remarkable feature of adaptive biology. After escaping the birth pore of its parental sporocyst, a cercaria (at least we infer from studies of other digeneans [1]) swims and crawls through the snail body cavity before it burrows through a pre-formed escape tunnel to the aquatic environment. Once in that milieu, a cyclical suite of swimming behaviours positions the cercaria for its potential assault on the skin of an available host, should one appear. Upon skin penetration, the larva (now called a schistosomulum) sits within the skin for up to 72 hours before tracking to the lung, whereupon it re-enters a second static phase. This journey takes the organism through three distinct environments (five if we include the solid integuments of snail and human hosts), incorporates a wholesale remodelling of the surface membrane, and includes two poorly understood periods of relative immobility in the skin and the lung. Further development in the liver is required before the adults reach their ultimate destination in the vasculature of the intestine or bladder. How the juvenile stages of schistosomes negotiate these environments is of intense interest, not the least because protective immunity in schistosome infections, when it occurs, appears to be directed against the early intra-host stages, with the principal target being the lung stage schistosomulum

Dynamics of Genome Rearrangement in Bacterial Populations:

Whole-genome sequencing has revealed that organisms exhibit extreme variability in chromosome structure. One common type of chromosome structure variation is genome arrangement variation: changes in the ordering of genes on the chromosome. Not only do we find differences in genome arrangement across species, but in some organisms, members of the same species have radically different genome arrangements. We studied the evolution of genome arrangement in pathogenic bacteria from the genus Yersinia. The Yersinia exhibit substantial variation in genome arrangement both within and across species. We reconstructed the history of genome rearrangement by inversion in a group of eight Yersinia, and we statistically quantified the forces shaping their genome arrangement evolution. In particular, we discovered an excess of rearrangement activity near the origin of chromosomal replication and found evidence for a preferred configuration for the relative orientations of the origin and terminus of replication. We also found real inversions to be significantly shorter than expected. Finally, we discovered that no single reconstruction of inversion history is parsimonious with respect to the total number of inversion mutations, but on average, reconstructed genome arrangements favor “balanced” genomes–where the replication origin is positioned opposite the terminus on the circular chromosome.

Computational Biology Resources Lack Persistence and Usability:

Innovation in computational biology research is predicated on the availability of published methods and computational resources. These resources facilitate the generation of new hypotheses and observations both on the part of the creators and the scientists who use them. These methods and resources include Web servers, databases, and software, both complex and simple, that implement a specific procedure or algorithm. Usually, a resource is maintained by the laboratory in which it was initially developed. We would assert that there is a growing level of frustration among scientists who attempt to use many of these resources and find that they no longer exist or are not properly maintained. Whether you agree or disagree with this statement and the evidence that follows, we welcome your thoughts and invite you to add a Comment to this article to share your own experiences and perspectives.