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

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

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

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

Weird Shrimp Has Astounding Vision:

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

Human Vision Inadequate For Research On Bird Vision:

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

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

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

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

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

Teen Helps Design Classroom DNA Experiments Using Common Food Dyes:

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

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

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

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

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

Sticky Gecko Feet: The Role of Temperature and Humidity:

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

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

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

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

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

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College Student Sleep Patterns Could Be Detrimental:

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

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

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

Ancient Protein Offers Clues To Killer Condition:

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

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

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

Psychological Stress Linked To Overeating, Monkey Study Shows:

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

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

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

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

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

Architecture For Fundamental Processes Of Life Discovered:

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

Female Concave-eared Frogs Draw Mates With Ultrasonic Calls:

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

Math Plus ‘Geeky’ Images Equals Deterred Students:

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

Kids Think Eyeglasses Make Other Kids Look Smart:

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

Genetics Confirm Oral Traditions Of Druze In Israel:

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

Worms Triple Sperm Transfer When Paternity Is At Risk:

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

Fish Diet To Avoid Fights With Slightly Larger Rivals:

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

What Does The Label On Your Chicken Really Mean?:

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

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

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

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

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

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

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

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

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

‘Early Birds’ Adapt To Climate Change:

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

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

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

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

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

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

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

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

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

How ‘Horse Tranquilizer’ Stops Depression:

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

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

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

Federal Polar Bear Research Critically Flawed, Forecasting Expert Asserts:

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

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

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

Koalas Under Threat From Climate Change:

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

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

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

Why Face Symmetry Is Sexy Across Cultures And Species:

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

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

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

Biodiversity: It’s In The Water:

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

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

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

Mathematics Simplifies Sleep Monitoring:

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

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

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

Does The Brain Control Muscles Or Movements?:

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

Killer Competition: Neurons Duke It Out For Survival:

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