“Boys Can Be Anything”: Effect of Barbie Play on Girls’ Career Cognitions
Abstract
Play with Barbie dolls is an understudied source of gendered socialization that may convey a sexualized adult world to young girls. Early exposure to sexualized images may have unintended consequences in the form of perceived limitations on future selves. We investigated perceptions of careers girls felt they could do in the future as compared to the number of careers they felt boys could do as a function of condition (playing with a Barbie or Mrs. Potato Head doll) and type of career (male dominated or female dominated) in a sample of 37 U.S. girls aged 4–7 years old residing in the Pacific Northwest. After a randomly assigned 5-min exposure to condition, children were asked how many of ten different occupations they themselves could do in the future and how many of those occupations a boy could do. Data were analyzed with a 2 × 2 × 2 mixed factorial ANOVA. Averaged across condition, girls reported that boys could do significantly more occupations than they could themselves, especially when considering male-dominated careers. In addition, girls’ ideas about careers for themselves compared to careers for boys interacted with condition, such that girls who played with Barbie indicated that they had fewer future career options than boys, whereas girls who played with Mrs. Potato Head reported a smaller difference between future possible careers for themselves as compared to boys. Results support predictions from gender socialization and objectification theories. http://link.springer.com/article/10.1007%2Fs11199-014-0347-y
Fish are losing their survival instinct — even becoming attracted to the smell of their predators — as the world's oceans become more acidic because of climate change, new research said on Monday.
The study of fish in coral reefs off the coast of Papua New Guinea — where the waters are naturally acidic — showed the animals' behaviour became riskier.
"Fish will normally avoid the smell of a predator, that makes perfect sense," lead author Professor Philip Munday from Australia's James Cook University told AFP.
"But they start to become attracted to the smell of the predator. That's incredible.
"They also swim further from shelter and they are more active, they swim around more. That's riskier behaviour for them — they are more likely to be attacked by a predator."
Munday said the research, published in the journal Nature Climate Change, was important given that about 30 percent of the carbon dioxide released into the atmosphere is ultimately absorbed by the ocean, a process which results in the seas becoming more acidic.
Acidification around the reefs studied is at levels predicted to become ocean-wide by the end of the century as the climate changes.
Munday said the fish appeared to have failed to adapt to the conditions, despite living their whole lives exposed to high levels of carbon dioxide.
"They didn't seem to adjust within their lifetime," Munday said. "That tells us that they don't adjust when they are permanently exposed to these higher carbon dioxide levels and we would have to think about whether adaptation would be possible over the coming decades."
Munday said the "seep" to which the fish were exposed — in which carbon dioxide from undersea volcanic activity bubbles to the surface — was the perfect "natural laboratory" for the study.
Close to the seep there is no coral growth, but further away lies a unique coral reef zone with carbon dioxide levels similar to those forecast for future decades.
Co-author Jodie Rummer said while the increased carbon dioxide in the water affected how fish behaved, it did not appear to affect their athletic performance.
"The metabolic rates of fish from the seep area were the same as fish from nearby 'healthy' reefs," she said in a statement.
"So, it seems that future ocean acidification may affect the behaviour of reef fishes more than other aspects of their performance."
The research was conducted by James Cook's Coral Centre of Excellence, the Australian Institute of Marine Science, Georgia Institute of Technology and the National Geographic Society.
Health risks from mobile wireless devices like phones and tablets are growing stronger, and require immediate action, says a new study. According to the BioInitiative Working Group, which released a mid-year update covering new science studies from 2012 to 2014, new studies intensify medical concerns about malignant brain tumours from cell phone use.
"There is a consistent pattern of increased risk for glioma (a malignant brain tumour ) and acoustic neuroma with use of mobile and cordless phones," said Lennart Hardell from Orebro University , Sweden. "Epidemiological evidence shows that radio frequency should be classified as a known human carcinogen. The existing FCC/IEEE and ICNIRP public safety limits are not adequate to protect public health," Hardell said.
The BioInitiative reports nervous system effects in 68% of studies on radio frequency radiation (144 of 211 studies) in 2014. This has increased from 63% in 2012 (93 of 150 studies). Studies of extremely-low frequency radiation are reported to cause nervous system effects in 90% of the 105 studies available in 2014.
Genetic effects (damage to DNA) from radio frequency radiation is reported in 65% (74 of 114 studies); and 83% (49 of 59 studies) of extremely low frequency studies. Wireless devices like phones and tablets are big sources of unnecessary biological stress to the mind and body that can chip away at resilience over time. The report warns against wireless in schools. Schools should provide internet access without Wi-Fi. -Agencies
In a ground-breaking trial, researchers in the UK will test artificial blood made from human stem cells in patients for the first time.
The research, planned for 2016, could pave the way for manufacturing of blood on an industrial scale, which could even supersede donated blood as the main supply for patients.
"We have made red blood cells, for the first time, that are fit to go in a person's body. Before now, we haven't really had that," said Marc Turner, medical director at the Scottish National Blood Transfusion Service, who is leading the 5 million pounds project at the University of Edinburgh. _PTI
Five mutations could make bird flu spread easily Handful of alterations can turn H5N1 avian influenza into virus that infects mammals through the air
Recently, A/H5N1 influenza viruses were shown to acquire airborne transmissibility between ferrets upon targeted mutagenesis and virus passage. The critical genetic changes in airborne A/Indonesia/5/05 were not yet identified. Here, five substitutions proved to be sufficient to determine this airborne transmission phenotype. Substitutions in PB1 and PB2 collectively caused enhanced transcription and virus replication. One substitution increased HA thermostability and lowered the pH of membrane fusion. Two substitutions independently changed HA binding preference from α2,3-linked to α2,6-linked sialic acid receptors. The loss of a glycosylation site in HA enhanced overall binding to receptors. The acquired substitutions emerged early during ferret passage as minor variants and became dominant rapidly. Identification of substitutions that are essential for airborne transmission of avian influenza viruses between ferrets and their associated phenotypes advances our fundamental understanding of virus transmission and will increase the value of future surveillance programs and public health risk assessments. http://www.cell.com/cell/abstract/S0092-8674%2814%2900281-5
Revealing camouflaged bacteria A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so called interferon-induced GTPases reveal and eliminate the bacterium's camouflage in the cell, enabling the cell to recognize the pathogen and to render it innocuous. The findings are published in the current issue of the science magazine Nature. Bacteria have developed countless strategies to hide themselves in order to evade attack by the immune system. In the body, Salmonella bacteria use macrophages as host cells to ensure their survival and to be able to spread within the body. Their survival strategy is to nestle into a vacuole within the cytoplasm of a macrophage, hiding there and multiplying. While they are hidden there, the immune cells cannot detect the bacteria and fight them.
A research team reports in the April 16 Science Translational Medicine that after a small group of ferrets were exposed to the canine distemper virus—a close cousin of measles—and then three days later treated with a newly developed antiviral medication, the disease was completely suppressed. All three of the exposed animals not only survived the virus but developed high amounts of protective antibodies against it, likely protecting them against future exposures (although the research team has not yet explored how long that immunity lasts). “We strongly support vaccination,” says study author Richard Plemper of the Institute for Biomedical Sciences at Georgia State University. “This drug was not developed as an alternative to vaccination but rather as an additional weapon in our arsenal against the virus that may enable us to improve disease management and rapidly silence outbreaks,” he says. The researchers hope that a therapeutic drug will be particularly useful for combating outbreaks in unvaccinated hotspots.
'Could an Oral Measles Drug Help the Unvaccinated?'
A medication designed to inhibit measleslike virus in infected ferrets shows promise http://www.scientificamerican.com/article/could-an-oral-measles-dru...
Opinion: Science Is Running Out of Things to Discover The advancing age when Nobelists receive their prizes could suggest fewer breakthroughs are waiting to happen The latest evidence is a "Correspondence" published today in the journal Nature. A group of six researchers, led by Santo Fortunato, professor of complex systems at Aalto University in Finland, points out that it is taking longer and longer for scientists to receive Nobel Prizes for their work. http://news.nationalgeographic.com/news/2014/04/140409-nobel-prize-...
(What rubbish?! We have lots to discover in life sciences, chemistry and Physics. Just taking into account only Astrophysics to write this article is dumb- Krishna)
Sperm RNA Carries Marks of Trauma Stress alters the expression of small RNAs in male mice and leads to depressive behaviors in later generations
-Nature.com
Pine forests are chock full of wild animals and plant life, but there's an invisible machine underground. Huge populations of fungi are churning away in the soil, decomposing organic matter and releasing carbon into the atmosphere. Despite the vital role these fungi play in ecological systems, their identities have only now been revealed. A Stanford-led team of scientists has generated a genetic map of more than 10,000 species of fungi across North America. The work was published this week in the Proceedings of the National Academy of Sciences. http://esciencenews.com/articles/2014/04/17/stanford.biologists.hel...!+Science+News+-+Popular%29
New Memory Model Explains How Neurons Select Memories Neuroscientists have discovered much about how long-term memories are stored in recent decades. For example, a number of proteins are quickly made in activated brain cells in order to create new memories for significant events, and some of those proteins remain at specific places on certain neurons for a few hours before breaking down.
It is this chain of biochemical occurrences that make it possible for people to remember key details about a particular event. However, one difficulty when it comes to modeling memory storage is trying to explain why only certain details and not everything that happened in that one or two hour window is retained.
Using data from previous research in the field as a starting point, Sejnowski and his colleagues developed a model that bridges the gap between molecular findings and memory systems observations in order to better explain how this 60 to 120 minute memory window works. Their findings, which could provide new insight in dealing with conditions such as Alzheimer’s and PTSD, appear in the latest edition of the journal Neuron. - http://www.cell.com/neuron/home
New evidence of suicide epidemic among India's 'marginalized' farmers: A new study has found that India's shocking rates of suicide are highest in areas with the most debt-ridden farmers who are clinging to tiny smallholdings -- less than one hectare -- and trying to grow 'cash crops', such as cotton and coffee, that are highly susceptible to global price fluctuations. The research supports a range of previous case studies that point to a crisis in key areas of India's agriculture sector following the 'liberalization' of the nation's economy during the 1990s. Researchers say that policy intervention to stabilize the price of cash crops and relieve indebted farmers may help stem the tide of suicide that has swept the Indian countryside.
Suicide rates vary sharply across the different Indian states. Building on the LSHTM study, researchers from Cambridge and UCL analysed suicide figures of 18 Indian states – as well as national crime and census statistics and surveying done by the Ministry of Agriculture – to create data models that investigated whether case studies of "farmer suicide" that concentrate on a few suicide hotspots could be generalised across India.
The team, from the Cambridge University's Department of Sociology and University College London's Department of Political Science, say they have found significant causal links showing that the huge variation in suicide rates between Indian states can largely be accounted for by suicides among farmers and agricultural workers.
Farmers at highest risk have three characteristics: those that grow cash crops such as coffee and cotton; those with 'marginal' farms of less than one hectare; and those with debts of 300 Rupees or more. Indian states in which these characteristics are most prevalent had the highest suicide rates. In fact, these characteristics account for almost 75% of the variability in state-level suicides. Source: The lancet
First Earth-Size Planet That Could Support Life found For the first time, scientists have discovered an Earth-size alien planet in the habitable zone of its host star, an "Earth cousin" that just might have liquid water and the right conditions for life.
The newfound planet, called Kepler-186f, was first spotted by NASA's Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth's sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say. You can learn more about the amazing alien planet find in a video produced by Space.com.
"One of the things we've been looking for is maybe an Earth twin, which is an Earth-size planet in the habitable zone of a sunlike star," Tom Barclay, Kepler scientist and co-author of the new exoplanet research, told Space.com. "This [Kepler-186f] is an Earth-size planet in the habitable zone of a cooler star. So, while it's not an Earth twin, it is perhaps an Earth cousin. It has similar characteristics, but a different parent."
Scientists have identified a long-sought fertility protein that allows sperm to dock to the surface of an egg. The finding, an important step in understanding the process that enables conception, could eventually spawn new forms of birth control and treatments for infertility.“It’s very important, because we now know two of the proteins that are responsible for the binding of sperm to the egg”. - Nature.com
Refining The Language For Chromosomes Researchers propose classification system revolutionizing communication of chromosomal abnormalities for research and clinical settings
'Describing Sequencing Results of Structural Chromosome Rearrangements with a Suggested Next-Generation Cytogenetic Nomenclature' http://www.cell.com/ajhg/abstract/S0002-9297%2814%2900172-4
The cause of neuronal death in Parkinson's disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person's own immune system, similar to the way autoimmune diseases like type I diabetes, celiac disease, and multiple sclerosis attack the body's cells. The study was published April 16, 2014, in Nature Communications. "This is a new, and likely controversial, idea in Parkinson's disease; but if true, it could lead to new ways to prevent neuronal death in Parkinson's that resemble treatments for autoimmune diseases," said the study's senior author, David Sulzer, PhD, professor of neurobiology in the departments of psychiatry, neurology, and pharmacology at Columbia University College of Physicians & Surgeons.
The new hypothesis about Parkinson's emerges from other findings in the study that overturn a deep-seated assumption about neurons and the immune system. http://www.cumc.columbia.edu/
Differences Between Neanderthals And Modern Man Caused By Genetic Switches With Neanderthals and modern humans sharing more than 99.8 percent of their genetic material, the differences in DNA between the two species are fairly minimal and a new study has found that the differences seen in phenotypes are mostly caused by certain genes being “switched on” or “switched off.”
According to the study published in the journal Science, genetic switches that affect the size and shape of limbs, as well as those that affect the development of the brain, are the most pronounced differences.
The study brings up the importance of researching the epigenome, or the genetic aspects that are responsible for switching on or off certain genes. Recent research has revealed how the epigenome can affect everything from cancer risk to the subtle differences between identical twins, each of whom have a copy of the same genetic material. The switching off of genes is typically achieved through a process called methylation – in which a methyl group, comprised of a carbon atom and three hydrogen atoms, is attached to a gene.
To uncover the epigenomic differences between Neanderthals and moderns humans, scientists took genetic material from limb bones of a living person, a Neanderthal and a Denisovan – an extinct Stone Age human that lived in Eurasia.
The study team was able to find approximately 2,200 regions that were triggered in today’s humans, but switched off in either or both extinct species, or the other way around. One of the main differences identified by the team was a group of five genes called HOXD, which impacts the appearance and size of limbs. It was mainly silenced in both ancient species, the scientists said. The HOXD differences could explain Neanderthals’ characteristic shorter limbs, bowleggedness and oversized hands and fingers.
Chris Stringer of the Natural History Museum in London, who was not directly involved in the study, told Reuters that the HOXD gene finding “may help to explain how these ancient humans were able to build stronger bodies, better adapted to the physical rigors of Stone Age life.”
The study team noted that the epigenome can be affected by lifestyle and environmental factors. This means that the differences observed could be unique to the individual sampled – rather than being representative on an entire species.
The researchers also found major epigenomic differences with respect to genes known to be related to neurological and psychiatric disorders such as autism and Alzheimer’s disease. These genes were silenced in the Neanderthal samples.
A groundbreaking study published in PLOS ONE by Prof. Iris Berent of Northeastern University and researchers at Harvard Medical School shows the brains of individual speakers are sensitive to language universals. Syllables that are frequent across languages are recognized more readily than infrequent syllables. Simply put, this study shows that language universals are hardwired in the human brain.
LANGUAGE UNIVERSALS
Language universals have been the subject of intense research, but their basis remains elusive. Indeed, the similarities between human languages could result from a host of reasons that are tangential to the language system itself. Syllables like lbog, for instance, might be rare due to sheer historical forces, or because they are just harder to hear and articulate. A more interesting possibility, however, is that these facts could stem from the biology of the language system. Could the unpopularity of lbogs result from universal linguistic principles that are active in every human brain? http://www.northeastern.edu/cos/2014/04/iris-berent/
Older women with gumption score high on compassion
Researchers at the University of California, San Diego School of Medicine report that older women, plucky individuals and those who have suffered a recent major loss are more likely to be compassionate toward strangers than other older adults.
The study is published in this month’s issue of the International Journal of Geriatric Psychiatry.
Northwestern synthetic biology team has created a new technology for modifying human cells to create programmable therapeutics that could travel the body and selectively target cancer and other sites of disease.
Engineering cell-based, biological devices that monitor and modify human physiology is a promising frontier in clinical synthetic biology. However, no existing technology enabled bioengineers to build such devices that sense a patient’s physiological state and respond in a customized fashion.
“The project addressed a key gap in the synthetic biology toolbox,” says Joshua Leonard, assistant professor of chemical and biological engineering in Northwestern’s McCormick School of Engineering and Applied Science. “There was no way to engineer cells in a manner that allowed them to sense key pieces of information about their environment, which could indicate whether the engineered cell is in healthy tissue or sitting next to a tumor.”
The extent to which biodiversity change in local assemblages contributes to global biodiversity loss is poorly understood. We analyzed 100 time series from biomes across Earth to ask how diversity within assemblages is changing through time. We quantified patterns of temporal α diversity, measured as change in local diversity, and temporal β diversity, measured as change in community composition. Contrary to our expectations, we did not detect systematic loss of α diversity. However, community composition changed systematically through time, in excess of predictions from null models. Heterogeneous rates of environmental change, species range shifts associated with climate change, and biotic homogenization may explain the different patterns of temporal α and β diversity. Monitoring and understanding change in species composition should be a conservation priority. --
Biodiversity Survives Extinctions for Now
A meta-analysis of ecosystems finds that species losses in any given place do not yet translate to large changes in the number of different species in that place. http://www.scientificamerican.com/podcast/episode/biodiversity-surv...
What Is the Deep Web? The internet is huge. I'm sure many of you know that, but it's almost unbelievable that when Googling the term "cat videos" that Google can serve up nearly a billion hits from all across the web. Now keep in mind there are 7 billion people on the planet. It's mind boggling.
But what if I were to tell you that Google and other search engines can only search a fraction of the web. This number varies from source to source, but the most generous term that I've heard is that Google can search about 10% of the world wide web. So what's in the other 90%?
Well I can assure you it's probably not another billion cat videos!
Tech Talker will be talking about the dark side of the web that Google won't show you.
This other 90% of the web goes by many different names: Dark Net, Invisible Web, Dark Web, Deep Web, Deep Net.
Biofuels from crop residue can reduce soil carbon and increase CO2 emissions Biofuels made using corn waste could release 7 percent more greenhouse gases in the early years compared to conventional gasoline. As a result, this type of cellulosic ethanol could be inelligible to meet quotas under the 2007 Energy Independence and Security Act (EISA).
According to a new study published yesterday in Nature Climate Change, this type of cellulosic biofuel could result in a 7% net increase in emissions. The government-funded research states that the main cause of this increase comes down to absolute changes in soil carbon content.
The carbon content of soil is broadly a function of new inputs (plant and animal material) and losses (predominately via erosion and respiration). Conventionally, corn crop residue is left on the field after harvest in order to reduce soil erosion and maintain the carbon stocks and soil fertility.
By removing corn waste from fields, models indicate that soil carbon content will decrease over time. In turn, corn-waste ethanol will effectively produce 7% more carbon dioxide equivalent than conventional gasoline in the short-term. While the results vary according to the amount of carn residue that is removed, any removal resulted in a net increase in emissions in the model.
In the longer-term, the study says that these types of biofuels will result in a net emissions decrease. However, the short term increase is enough to keep this type of biofuel from complying with regulations in the 2007 Energy Independence and Security Act (EISA). This Act requires that biofuels produce 60% less pollution than conventional gasoline. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2...
Elections 2014: Politicians told to do more for science and technology The scientific community demands that the next government at the centre set aside a bigger chunk of the budget for research and development, create infrastructure for "continuous innovations" and boost science movements among the electorate and dovetail this with the private sector's aid. http://gadgets.ndtv.com/science/news/election-2014-politicians-told...
The connection between heart attack fight and birds A new study into how the world's highest flying bird, bar-headed geese, is able to survive at extreme altitudes may have future implications for low-oxygen medical conditions in humans. An international team of scientists recently tracked bar-headed geese while they migrated across the Himalayas. They found that these birds are able to tolerate running at top speed while breathing only 7% oxygen.
Lucy Hawkes of the University of Exeter, along with colleagues Charles Bishop (Bangor University) and Pat Butler (University of Birmingham) tested how the geese were at coping with exercise in reduced oxygen environments by simulating the conditions of Mt Everest in a clear box and then getting the birds to run as fast as possible on a treadmill inside the box. The air on the highest mountains is made up of 7% oxygen compared with 21% at sea level.
Hawkes said, "It all seems to come down to how much oxygen bar-headed geese can supply to their heart muscles. The more they supply, the faster their heart beats and keeps the supply of oxygen to the rest of the body going." He added, "The wider implications of these findings are for low-oxygen medical conditions in humans, such as heart attack and stroke — suggesting what adaptations might help prevent problems in the first place and learning how animals have managed to cope with really extreme environments." -TNN
Antibiotics: A new spanner in the works of bacterial transcription A promising molecular target that is unlikely to develop antibiotic resistance has been identified in bacteria. http://elifesciences.org/content/3/e02840
Cow poop promotes the spread of antibiotic resistant bacteria
Manure from dairy cows has been defined as an increasing source of bacteria that can become resistant to antibiotics. These findings are the result of the work of Fabienne Wichmann and colleagues at Yale University in New Haven, Connecticut. The research was published in the April 22, 2014, edition of the journal mBio®.
Bacteria that are antibiotic resistant reach the food chain of humans through the use of cow manure as fertilizer. The manure may or may not contain bacteria that are antibiotic resistant. If the manure does contain an antibiotic resistant strain of bacteria then there is a potential for transmission to humans that eat food that was fertilized with cow manure. The food plants can even become a source of antibiotic resistance due to the phenomenon of gene exchange between species.
A more prominent and more likely transfer of new antibiotic bacterial species to humans is through infection of cow farmers by new bacterial strains. The dairy cow farmers can transmit a new disease directly to other humans through physical contact or through airborne distribution during coughing or sneezing. The more humans that come into contact with a potentially antibiotic resistant type of bacteria increases the probability that the bacteria will become resistant to antibiotics due in part to the high level of use of antibiotics by humans.
The researchers found that only five samples of cow manure contained 80 unique and functional antibiotic resistance genes. The scientists created a laboratory cultured strain of Escherichia coli that was resistant to one of the four major types of antibiotics used to treat humans from the 80 genes. The scientists also found a never before known family of antibiotic resistant genes that conferred resistance to the same group of antibiotics.
A primary source of antibiotic resistant bacteria origination is the use of antibiotics to keep cattle healthy. The potential for transfer of antibiotic resistance to humans through food crops depends on whether the cow manure has antibiotic resistant bacteria or genes. It is possible that a new antibiotic resistant disease could be contracted by people simply by using cow manure as fertilizer for their house plants or home garden. Source: http://www.examiner.com/article/cow-poop-promotes-the-spread-of-ant...
Citizen scientists pitch new uses for paper microscope Ten thousand ‘print-and-fold’ paper microscopes initially designed as low-cost medical diagnostic tools are being given away to researchers and citizen scientists who come up with novel ways to use them to test their ideas.
The goal of the Ten Thousand Microscopes initiative, funded by the Gordon and Betty Moore Foundation, is to create a crowdsourced lab manual for Foldscope, the low-cost microscope launched earlier this year by a US bioengineering team that combines pragmatic, origami design with sophisticated micro-optics.
The idea is to make “microscopy for everyone”, says Manu Prakash, a bioengineering researcher at Stanford University, United States, who led the development of the frugal innovation to address the lack of cheap, easy-to-use diagnostic tools for diseases in remote and impoverished communities. http://www.scidev.net/global/biotechnology/news/citizen-scientists-...
Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity Researchers from Singapore and Germany have found a new way to study the curious properties observed at the interface of materials.
An international team led by researchers at the National University of Singapore (NUS) has developed a technique to study the interface between materials, shedding light on the curious properties that arise when two materials are put together.
Studying material interfaces is part of a research area known as condensed matter physics. When matter is condensed, mutual interactions between particles alters physical behavior, giving rise to exotic properties. A better understanding of how materials interface allows scientists to tweak material properties to possibly develop better solar cells, superconductors and smaller hard drives.
“If you put two materials together, you can create completely new properties. For instance, two non-conducting, non-magnetic insulators can become conducting and in some cases ferromagnetic and superconducting at their interface,” explains NUS Assistant Professor Andrivo Rusydi, who led the research.
The team investigated the electrical conductivity of strontium titanate and lanthanum aluminate, two insulators that become conductors at their interface. They observed that conductivity was ten-fold less than what was predicted theoretically, meaning that 90 percent of the expected electrons were missing.
To find the missing electrons, the team used high-energy reflectivity and spectroscopic ellipsometry experiments which flooded the interface with a wide range of energy. This revealed electrons that were bound within the molecular lattice, which prevented them from moving and explained the observed low conductivity.
The team’s new approach and insights, which culminated in a recent publication with Nature Communications, will be used for further investigations on the basic interface characteristics among materials.
Research at the University of Adelaide has shed new light onto the possible causes of sudden infant death syndrome (SIDS), which could help to prevent future loss of children’s lives.
Researchers in the University’s School of Medical Sciences have found that telltale signs in the brains of babies that have died of SIDS are remarkably similar to those of children who died of accidental asphyxiation. 'β-Amyloid precursor protein staining of the brain in sudden infant and early childhood death' http://onlinelibrary.wiley.com/doi/10.1111/nan.12109/abstract;jsess...
Parts of Antarctica, one of the coldest places on Earth, were as warm as today's California coast about 40 million years ago with temperatures as high as 17 degrees Celsius, a new study has found.
Researchers also found that the polar regions of the southern Pacific Ocean once registered 21st-century Florida heat.
The findings underscore the potential for increased warmth at Earth's poles and the associated risk of melting polar ice and rising sea levels, the researchers said.
Led by scientists at Yale University, the study focused on Antarctica during the Eocene epoch, 40-50 million years ago, a period with high concentrations of atmospheric CO2 and consequently a greenhouse climate.
Today, Antarctica is year-round one of the coldest places on Earth, and the continent's interior is the coldest place, with annual average land temperatures far below zero degrees Fahrenheit.
The new measurements can help improve climate models used for predicting future climate, according to co-author Hagit Affek, associate professor of geology & geophysics at Yale. -PTI
Agenetic disease has been cured in living, adult animals for the first time using a revolutionary genome-editing technique that can make the smallest changes to the vast database of the DNA molecule with pinpoint accuracy.
Scientists have used the genome-editing technology to cure adult laboratory mice of an inherited liver disease by correcting a single "letter" of the genetic alphabet which had been mutated in a vital gene involved in liver metabolism. A similar mutation in the same gene causes the equivalent inherited liver disease in humans — and the successful repair of the genetic defect in laboratory mice raises hopes that the first clinical trials on patients could begin within a few years, scientists said.
The success is the latest achievement in the field of genome editing. This has been transformed by the discovery of Crispr, a technology that allows scientists to make almost any DNA changes at precisely defined points on the chromosomes of animals or plants.
Crispr — pronounced "crisper" — was initially discovered in 1987 as an immune defence used by bacteria against invading viruses. Its powerful genome-editing potential in higher animals, including humans, was only fully realised in 2012 and 2013 when scientists showed that it can be combined with a DNAsniping enzyme called Cas9 and used to edit the human genome . Since then there has been an explosion of interest in the technology because it is such a simple method of changing the individual letters of the human genome — the 3 billion "base pairs" of the DNA molecule — with an accuracy equivalent to correcting a single misspelt word in a 23-volume encyclopaedia.
In the latest study, scientists at the Massachusetts Institute of Technology (MIT) used Crispr to locate and correct the single mutated DNA base pair in a liver gene known as LAH, which can lead to a fatal build-up of the amino acid tyrosine in humans and has to be treated with drugs and a special diet. The researchers effectively cured mice suffering from the disease by altering the genetic make-up of about a third of their liver cells using the Crispr technique, which was delivered by high-pressure intravenous injections.
"We basically showed you could use the Crispr system in an animal to cure a genetic disease, and the one we picked was a disease in the liver which is very similar to one found in humans," said professor Daniel Anderson of MIT, who led the study.
"The disease is caused by a single point mutation and we showed that the Crispr system can be delivered in an adult animal and result in a cure. We think it's an important proof of principle that this technology can be applied to animals to cure disease," Anderson said. "The fundamental advantage is that you are repairing the defect , you are actually correcting the DNA itself," he said. "What is exciting about this approach is that we can actually correct a defective gene in a living adult animal."
Jennifer Doudna, of the University of California, Berkeley , who was one of the codiscoverers of the Crispr technique , said professor Anderson's study is a "fantastic advance" because it demonstrates that it is possible to cure adult animals living with a genetic disorder.
"Obviously there would be numerous hurdles before such an approach could be used in people, but the simplicity of the approach, and the fact that it worked, really are very exciting," professor Doudna said. "I think there will be a lot of progress made in the coming one to two years in using this approach for therapeutics and other real-world applications," she added. ''Scientists ‘edit’ DNA to correct adult genes and cure diseases '' http://www.independent.co.uk/news/science/revealed-scientists-edit-...
The dual-allergen exposure hypothesis is the theory that exposure to food allergens through the skin can lead to allergy, while consumption of these foods at an early age may actually result in tolerance. Depending on the balance of these exposures, either tolerance or allergy will “win.” Children with eczema, for example, have a disrupted skin barrier that could allow exposure to food proteins in the environment – such as peanut oil in creams or peanut residue on tables. Under the hypothesis, if these children avoid peanuts but are still exposed to them in the environment, they might be more likely to develop peanut allergy.
Despite efforts to prevent food allergy (FA) in children, IgE-mediated FAs are increasing in westernized countries. Previous preventive strategies, such as prolonged exclusive breast-feeding and delayed weaning onto solid foods, have recently been called into question. The present review considers possible risk factors and theories for the development of FA. An alternative hypothesis is proposed, suggesting that early cutaneous exposure to food protein through a disrupted skin barrier leads to allergic sensitization and that early oral exposure to food allergen induces tolerance. Novel interventional strategies to prevent the development of FA are also discussed. http://www.ncbi.nlm.nih.gov/pubmed/22464642
Animal Kingdom Communication UM researcher discovers the most effective animal signal strategies.
There are all sorts of signaling strategies in nature. Peacocks puff out their feathers and spread their colorful tails; satin bowbirds build specialized stick structures, called bowers, and decorate them with blue and shiny objects; and European bitterling males show off bright nuptial coloration during spawning season. Each species has evolved a unique method to communicate with others.
“Signaling can have profound fitness implications for individuals that are either signaling or receiving the signal,” says Gavin M. Leighton, author of a new study on the effectiveness of signaling systems.
“For instance, individuals may signal to attract mates, or they may signal to rivals in order to defend a territory. Additionally, many biological models of cooperative behavior require individuals to signal how cooperative they were in past interactions.” Effective communication is not just about the signaler, according to the study, the receiver also needs to assess the signaler efficiently. For instance, one of the most effective strategies from the perspective of female birds is assessing groups of males called leks, where females can assess multiple males in a short period of time.
“When receivers had to assess individual signalers one at a time, the accuracy of their ranking of signalers decreased compared to when all the signalers could be observed simultaneously.”
The study also shows that individuals that used non-food items, like a twig, in their signaling display had the least effective strategy. Surprisingly, individuals that invest in ecological structures, such as building a nest, improved the ability of the females to rank signalers, but the effect was fairly weak.
“The most unexpected finding was that investing in some sort of temporally stable structure only weakly improved the ability for receivers to assess signalers,” Leighton, said. “I originally suspected that investing in a structure would allow individuals to quickly convey their signaling effort over time in a single, observable feature. While I did find that structures helped, the effect was not as strong as other the other variables.”
In order to investigate specific characteristics of systems and provide the ranking of signalers by receivers, Leighton designed a computer model that represents salient features of many signaling systems, across a variety of scenarios. The model is called an agent-based model. It allows the researcher to program individual entities with specified behaviors. Then, the software provides the ranking information to the researcher. Included in the analyses were different species of birds, fishes and insects.
“The study systematically models a series of behavioral and ecological conditions. To the best of my knowledge no one has performed a general analysis of these different types of signaling systems.” The study assumes that in every scenario individuals had perfect memory. In other words, when a receiver saw a signaling individual, they were able to unambiguously assign this effort to a specific individual. In nature, individuals probably make errors in assigning signaling effort or forget the effort of individuals over time.
“By itself, this seems like an unwarranted assumption, however, it is not easy to compare across signaling systems where memory also varies with the species in question,” Leighton says.
In the future, the researcher would like to include variation in the memory of individual receivers in these models. “There may be effects of imperfect memory that influence signaling effectiveness and I think this would be a good next step.” http://www.miami.edu/index.php/news/releases/animal_kingdom_communi...
Virus-Inspired Coating Protects DNA Nanostructures In The Body Nanomedicine: A lipid coating could protect DNA drug carriers in the bloodstream
Nanomedicines made from self-assembling DNA structures could last longer inside the bloodstream with a lipid bilayer coating similar to the ones worn by some viruses (ACS Nano 2014, DOI: 10.1021/nn5011914). This protection strategy could make it possible to test new kinds of DNA nanotherapies in animals and bring them to the clinic, the developers say.
DNA is a versatile building block for making nanoparticles with precise shapes that can perform complex tasks. For example, in 2012, researchers used DNA to fashion a drug-carrying box with two locks made from DNA; the box opens to release the drug only if both locks are bound to certain proteins on a target cell (Science, DOI: 10.1126/science.1214081). But researchers struggle to test this and other DNA nanotechnology in animals. Any free-floating DNA in the bloodstream is rapidly destroyed by enzymes. Researchers haven’t yet figured out how to package these DNA machines so that they can survive long enough in the body to do their work.
To solve this problem, William M. Shih, a synthetic biologist at Harvard University, looked to nature for inspiration. Viruses, which are essentially groups of genes that use living cells to replicate, have already developed strategies to endure in the bloodstream. One is to coat themselves with a protective lipid bilayer.
Shih decided to mimic this strategy. He first designed a simple octahedron-shaped wireframe of DNA using software his group had previously developed. Given the dimensions of a structure, this software generates a recipe list of DNA strands that will self-assemble into the desired shape. A DNA synthesis company makes the strands, and the researchers mix them in the lab.
Each strut in the DNA octahedron is made up of six 28-nm-long double helices held together by shorter strands. The Harvard group created attachment points on the interior and exterior surfaces of the octahedron using single-stranded pieces of DNA. On the interior, these handles bind to complementary DNA strands that carry fluorescent dyes so that the scientists could track the particles in animals. The exterior handles bind to complementary strands carrying lipids.
This created a 50-nm-diameter DNA octahedron with “greasy plugs” on it, Shih says. “Then we take this hairball and mix it with a solution of giant liposomes in surfactant.” The lipids from the liposomes stick to the plugs, eventually creating a continuous coating on the DNA frame. The completed structure is about 70 to 80 nm in diameter.
Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, have developed a design structure for composite materials that is more impact resistant and tougher than the standard used in airplanes.
Neuroscientists Discover Brain Circuits Involved in Emotion
Neuroscientists have discovered a brain pathway that underlies the emotional behaviours critical for survival. New research by the University of Bristol, published in the Journal of Physiology today [23 April], has identified a chain of neural connections which links central survival circuits to the spinal cord, causing the body to freeze when experiencing fear.
Understanding how these central neural pathways work is a fundamental step towards developing effective treatments for emotional disorders such as anxiety, panic attacks and phobias.
An important brain region responsible for how humans and animals respond to danger is known as the PAG (periaqueductal grey), and it can trigger responses such as freezing, a high heart rate, increase in blood pressure and the desire for flight or fight.
This latest research has discovered a brain pathway leading from the PAG to a highly localised part of the cerebellum, called the pyramis. The research went on to show that the pyramis is involved in generating freezing behaviour when central survival networks are activated during innate and learnt threatening situations.
The pyramis may therefore serve as an important point of convergence for different survival networks in order to react to an emotionally challenging situation. -Journal of Physiology
Royal Statistical Society looking for volunteer scientists Date: 22 Apr 2014
The Royal Statistical Society (RSS) is looking for volunteer scientists to take part in their programme of delivering science and statistics training to journalists.
Volunteers attend a ‘train the trainer’ workshop before signing up to deliver sessions at news outlets and journalism schools throughout the UK. Having successfully run the course for three years, the RSS is looking to widen their pool of volunteers.
Anyone interested in taking part should contact Vinet Campbell, National Coordinator for Science Journalism Training at V.Campbell@rss.org.uk. More information can also be found at their website. http://www.statslife.org.uk/resources/for-journalists
Breakthrough harnesses light for controlled chemical reaction When chemist Tehshik Yoon looks out his office window, he sees a source of energy to drive chemical reactions. Plants "learned" to synthesize chemicals with sunlight eons ago; Yoon came to the field a bit more recently. But this week, in the journal Science, he and three collaborators detail a way to use sunlight and two catalysts to create molecules that are difficult to make with conventional techniques.
In chemistry, heat and ultraviolet (UV) light are commonly used to drive reactions. Although light can power reactions that heat cannot, UV has disadvantages, says Yoon, a chemistry professor at University of Wisconsin-Madison. The UV often used in industry carries so much energy that "it's dangerous to use, unselective, and prone to making unwanted by-products."
Many chemicals exist in two forms that are mirror images of each other, and Yoon is interested in reactions that make only one of those images.
"It's like your hands," Yoon says. "They are similar, but not identical; a left-hand glove does not fit the right hand. It's the same way with molecules in biology; many fail unless they have the correct 'handedness,' or 'chirality.'"
The pharmaceutical industry, in particular, is concerned about controlling chirality in drugs, but making those shapes is a hit-or-miss proposition with UV light, Yoon says.
He says the new technique answers a question posed by a French chemist in 1874, who suggested using light to make products with controlled chirality. "Chemists could never do that efficiently, and so the prejudice was that it was too difficult to do." - University of Wisconsin-Madison
Ocean microbes display remarkable genetic diversity Scientists in MIT's Department of Civil and Environmental Engineering (CEE) recently performed a cell-by-cell genomic analysis on a wild population of Prochlorococcus living in a milliliter -- less than a quarter teaspoon -- of ocean water, and found hundreds of distinct genetic subpopulations.
- Massachusetts Institute of Technology
Dr. Krishna Kumari Challa
“Boys Can Be Anything”: Effect of Barbie Play on Girls’ Career Cognitions
Abstract
Play with Barbie dolls is an understudied source of gendered socialization that may convey a sexualized adult world to young girls. Early exposure to sexualized images may have unintended consequences in the form of perceived limitations on future selves. We investigated perceptions of careers girls felt they could do in the future as compared to the number of careers they felt boys could do as a function of condition (playing with a Barbie or Mrs. Potato Head doll) and type of career (male dominated or female dominated) in a sample of 37 U.S. girls aged 4–7 years old residing in the Pacific Northwest. After a randomly assigned 5-min exposure to condition, children were asked how many of ten different occupations they themselves could do in the future and how many of those occupations a boy could do. Data were analyzed with a 2 × 2 × 2 mixed factorial ANOVA. Averaged across condition, girls reported that boys could do significantly more occupations than they could themselves, especially when considering male-dominated careers. In addition, girls’ ideas about careers for themselves compared to careers for boys interacted with condition, such that girls who played with Barbie indicated that they had fewer future career options than boys, whereas girls who played with Mrs. Potato Head reported a smaller difference between future possible careers for themselves as compared to boys. Results support predictions from gender socialization and objectification theories.
http://link.springer.com/article/10.1007%2Fs11199-014-0347-y
Apr 15, 2014
Dr. Krishna Kumari Challa
Behavioural impairment in reef fishes caused by ocean acidification at CO2 seeps
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2...
Fish are losing their survival instinct — even becoming attracted to the smell of their predators — as the world's oceans become more acidic because of climate change, new research said on Monday.
The study of fish in coral reefs off the coast of Papua New Guinea — where the waters are naturally acidic — showed the animals' behaviour became riskier.
"Fish will normally avoid the smell of a predator, that makes perfect sense," lead author Professor Philip Munday from Australia's James Cook University told AFP.
"But they start to become attracted to the smell of the predator. That's incredible.
"They also swim further from shelter and they are more active, they swim around more. That's riskier behaviour for them — they are more likely to be attacked by a predator."
Munday said the research, published in the journal Nature Climate Change, was important given that about 30 percent of the carbon dioxide released into the atmosphere is ultimately absorbed by the ocean, a process which results in the seas becoming more acidic.
Acidification around the reefs studied is at levels predicted to become ocean-wide by the end of the century as the climate changes.
Munday said the fish appeared to have failed to adapt to the conditions, despite living their whole lives exposed to high levels of carbon dioxide.
"They didn't seem to adjust within their lifetime," Munday said. "That tells us that they don't adjust when they are permanently exposed to these higher carbon dioxide levels and we would have to think about whether adaptation would be possible over the coming decades."
Munday said the "seep" to which the fish were exposed — in which carbon dioxide from undersea volcanic activity bubbles to the surface — was the perfect "natural laboratory" for the study.
Close to the seep there is no coral growth, but further away lies a unique coral reef zone with carbon dioxide levels similar to those forecast for future decades.
Co-author Jodie Rummer said while the increased carbon dioxide in the water affected how fish behaved, it did not appear to affect their athletic performance.
"The metabolic rates of fish from the seep area were the same as fish from nearby 'healthy' reefs," she said in a statement.
"So, it seems that future ocean acidification may affect the behaviour of reef fishes more than other aspects of their performance."
The research was conducted by James Cook's Coral Centre of Excellence, the Australian Institute of Marine Science, Georgia Institute of Technology and the National Geographic Society.
Apr 15, 2014
Dr. Krishna Kumari Challa
Health risks from mobile wireless devices like phones and tablets are growing stronger, and require immediate action, says a new study. According to the BioInitiative Working Group, which released a mid-year update covering new science studies from 2012 to 2014, new studies intensify medical concerns about malignant brain tumours from cell phone use.
"There is a consistent pattern of increased risk for glioma (a malignant brain tumour ) and acoustic neuroma with use of mobile and cordless phones," said Lennart Hardell from Orebro University , Sweden. "Epidemiological evidence shows that radio frequency should be classified as a known human carcinogen. The existing FCC/IEEE and ICNIRP public safety limits are not adequate to protect public health," Hardell said.
The BioInitiative reports nervous system effects in 68% of studies on radio frequency radiation (144 of 211 studies) in 2014. This has increased from 63% in 2012 (93 of 150 studies). Studies of extremely-low frequency radiation are reported to cause nervous system effects in 90% of the 105 studies available in 2014.
Genetic effects (damage to DNA) from radio frequency radiation is reported in 65% (74 of 114 studies); and 83% (49 of 59 studies) of extremely low frequency studies. Wireless devices like phones and tablets are big sources of unnecessary biological stress to the mind and body that can chip away at resilience over time. The report warns against wireless in schools. Schools should provide internet access without Wi-Fi.
-Agencies
Apr 15, 2014
Dr. Krishna Kumari Challa
In a ground-breaking trial, researchers in the UK will test artificial blood made from human stem cells in patients for the first time.
The research, planned for 2016, could pave the way for manufacturing of blood on an industrial scale, which could even supersede donated blood as the main supply for patients.
"We have made red blood cells, for the first time, that are fit to go in a person's body. Before now, we haven't really had that," said Marc Turner, medical director at the Scottish National Blood Transfusion Service, who is leading the 5 million pounds project at the University of Edinburgh.
_PTI
Apr 15, 2014
Dr. Krishna Kumari Challa
Apr 16, 2014
Dr. Krishna Kumari Challa
Five mutations could make bird flu spread easily
Handful of alterations can turn H5N1 avian influenza into virus that infects mammals through the air
Recently, A/H5N1 influenza viruses were shown to acquire airborne transmissibility between ferrets upon targeted mutagenesis and virus passage. The critical genetic changes in airborne A/Indonesia/5/05 were not yet identified. Here, five substitutions proved to be sufficient to determine this airborne transmission phenotype. Substitutions in PB1 and PB2 collectively caused enhanced transcription and virus replication. One substitution increased HA thermostability and lowered the pH of membrane fusion. Two substitutions independently changed HA binding preference from α2,3-linked to α2,6-linked sialic acid receptors. The loss of a glycosylation site in HA enhanced overall binding to receptors. The acquired substitutions emerged early during ferret passage as minor variants and became dominant rapidly. Identification of substitutions that are essential for airborne transmission of avian influenza viruses between ferrets and their associated phenotypes advances our fundamental understanding of virus transmission and will increase the value of future surveillance programs and public health risk assessments.
http://www.cell.com/cell/abstract/S0092-8674%2814%2900281-5
Apr 16, 2014
Dr. Krishna Kumari Challa
Revealing camouflaged bacteria
A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so called interferon-induced GTPases reveal and eliminate the bacterium's camouflage in the cell, enabling the cell to recognize the pathogen and to render it innocuous. The findings are published in the current issue of the science magazine Nature. Bacteria have developed countless strategies to hide themselves in order to evade attack by the immune system. In the body, Salmonella bacteria use macrophages as host cells to ensure their survival and to be able to spread within the body. Their survival strategy is to nestle into a vacuole within the cytoplasm of a macrophage, hiding there and multiplying. While they are hidden there, the immune cells cannot detect the bacteria and fight them.
Apr 17, 2014
Dr. Krishna Kumari Challa
Apr 17, 2014
Dr. Krishna Kumari Challa
The recommendations include increasing hepatitis C screening, liver damage mitigation and how to select appropriate treatment for chronic infections.
WHO Issues First Hepatitis C Guidelines
Guidelines for the screening, care and treatment of persons with hepatitis C infection
http://www.who.int/hiv/pub/hepatitis/hepatitis-c-guidelines/en/
Apr 17, 2014
Dr. Krishna Kumari Challa
A research team reports in the April 16 Science Translational Medicine that after a small group of ferrets were exposed to the canine distemper virus—a close cousin of measles—and then three days later treated with a newly developed antiviral medication, the disease was completely suppressed.
All three of the exposed animals not only survived the virus but developed high amounts of protective antibodies against it, likely protecting them against future exposures (although the research team has not yet explored how long that immunity lasts). “We strongly support vaccination,” says study author Richard Plemper of the Institute for Biomedical Sciences at Georgia State University. “This drug was not developed as an alternative to vaccination but rather as an additional weapon in our arsenal against the virus that may enable us to improve disease management and rapidly silence outbreaks,” he says. The researchers hope that a therapeutic drug will be particularly useful for combating outbreaks in unvaccinated hotspots.
'Could an Oral Measles Drug Help the Unvaccinated?'
A medication designed to inhibit measleslike virus in infected ferrets shows promise
http://www.scientificamerican.com/article/could-an-oral-measles-dru...
Apr 18, 2014
Dr. Krishna Kumari Challa
Opinion: Science Is Running Out of Things to Discover
The advancing age when Nobelists receive their prizes could suggest fewer breakthroughs are waiting to happen
The latest evidence is a "Correspondence" published today in the journal Nature. A group of six researchers, led by Santo Fortunato, professor of complex systems at Aalto University in Finland, points out that it is taking longer and longer for scientists to receive Nobel Prizes for their work.
http://news.nationalgeographic.com/news/2014/04/140409-nobel-prize-...
(What rubbish?! We have lots to discover in life sciences, chemistry and Physics. Just taking into account only Astrophysics to write this article is dumb- Krishna)
Apr 18, 2014
Dr. Krishna Kumari Challa
Sperm RNA Carries Marks of Trauma
Stress alters the expression of small RNAs in male mice and leads to depressive behaviors in later generations
-Nature.com
Apr 18, 2014
Dr. Krishna Kumari Challa
Call for alternative identification methods for endangered species
http://esciencenews.com/articles/2014/04/17/call.alternative.identi...
Apr 18, 2014
Dr. Krishna Kumari Challa
Pine forests are chock full of wild animals and plant life, but there's an invisible machine underground. Huge populations of fungi are churning away in the soil, decomposing organic matter and releasing carbon into the atmosphere. Despite the vital role these fungi play in ecological systems, their identities have only now been revealed. A Stanford-led team of scientists has generated a genetic map of more than 10,000 species of fungi across North America. The work was published this week in the Proceedings of the National Academy of Sciences.
http://esciencenews.com/articles/2014/04/17/stanford.biologists.hel...!+Science+News+-+Popular%29
Apr 18, 2014
Dr. Krishna Kumari Challa
Clean air: Fewer sources for self-cleaning
http://esciencenews.com/articles/2014/04/17/clean.air.fewer.sources...
Apr 18, 2014
Dr. Krishna Kumari Challa
New Memory Model Explains How Neurons Select Memories
Neuroscientists have discovered much about how long-term memories are stored in recent decades. For example, a number of proteins are quickly made in activated brain cells in order to create new memories for significant events, and some of those proteins remain at specific places on certain neurons for a few hours before breaking down.
It is this chain of biochemical occurrences that make it possible for people to remember key details about a particular event. However, one difficulty when it comes to modeling memory storage is trying to explain why only certain details and not everything that happened in that one or two hour window is retained.
Using data from previous research in the field as a starting point, Sejnowski and his colleagues developed a model that bridges the gap between molecular findings and memory systems observations in order to better explain how this 60 to 120 minute memory window works. Their findings, which could provide new insight in dealing with conditions such as Alzheimer’s and PTSD, appear in the latest edition of the journal Neuron.
- http://www.cell.com/neuron/home
Apr 18, 2014
Dr. Krishna Kumari Challa
New evidence of suicide epidemic among India's 'marginalized' farmers:
A new study has found that India's shocking rates of suicide are highest in areas with the most debt-ridden farmers who are clinging to tiny smallholdings -- less than one hectare -- and trying to grow 'cash crops', such as cotton and coffee, that are highly susceptible to global price fluctuations. The research supports a range of previous case studies that point to a crisis in key areas of India's agriculture sector following the 'liberalization' of the nation's economy during the 1990s. Researchers say that policy intervention to stabilize the price of cash crops and relieve indebted farmers may help stem the tide of suicide that has swept the Indian countryside.
Suicide rates vary sharply across the different Indian states. Building on the LSHTM study, researchers from Cambridge and UCL analysed suicide figures of 18 Indian states – as well as national crime and census statistics and surveying done by the Ministry of Agriculture – to create data models that investigated whether case studies of "farmer suicide" that concentrate on a few suicide hotspots could be generalised across India.
The team, from the Cambridge University's Department of Sociology and University College London's Department of Political Science, say they have found significant causal links showing that the huge variation in suicide rates between Indian states can largely be accounted for by suicides among farmers and agricultural workers.
Farmers at highest risk have three characteristics: those that grow cash crops such as coffee and cotton; those with 'marginal' farms of less than one hectare; and those with debts of 300 Rupees or more. Indian states in which these characteristics are most prevalent had the highest suicide rates. In fact, these characteristics account for almost 75% of the variability in state-level suicides.
Source: The lancet
Apr 18, 2014
Dr. Krishna Kumari Challa
First Earth-Size Planet That Could Support Life found
For the first time, scientists have discovered an Earth-size alien planet in the habitable zone of its host star, an "Earth cousin" that just might have liquid water and the right conditions for life.
The newfound planet, called Kepler-186f, was first spotted by NASA's Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth's sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say. You can learn more about the amazing alien planet find in a video produced by Space.com.
"One of the things we've been looking for is maybe an Earth twin, which is an Earth-size planet in the habitable zone of a sunlike star," Tom Barclay, Kepler scientist and co-author of the new exoplanet research, told Space.com. "This [Kepler-186f] is an Earth-size planet in the habitable zone of a cooler star. So, while it's not an Earth twin, it is perhaps an Earth cousin. It has similar characteristics, but a different parent."
http://www.space.com/25530-earthsize-exoplanet-kepler-186f-habitabl...
Apr 19, 2014
Dr. Krishna Kumari Challa
Apr 19, 2014
Dr. Krishna Kumari Challa
Scientists have identified a long-sought fertility protein that allows sperm to dock to the surface of an egg. The finding, an important step in understanding the process that enables conception, could eventually spawn new forms of birth control and treatments for infertility.“It’s very important, because we now know two of the proteins that are responsible for the binding of sperm to the egg”.
- Nature.com
Apr 19, 2014
Dr. Krishna Kumari Challa
Refining The Language For Chromosomes
Researchers propose classification system revolutionizing communication of chromosomal abnormalities for research and clinical settings
'Describing Sequencing Results of Structural Chromosome Rearrangements with a Suggested Next-Generation Cytogenetic Nomenclature'
http://www.cell.com/ajhg/abstract/S0002-9297%2814%2900172-4
Apr 19, 2014
Dr. Krishna Kumari Challa
The cause of neuronal death in Parkinson's disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person's own immune system, similar to the way autoimmune diseases like type I diabetes, celiac disease, and multiple sclerosis attack the body's cells. The study was published April 16, 2014, in Nature Communications. "This is a new, and likely controversial, idea in Parkinson's disease; but if true, it could lead to new ways to prevent neuronal death in Parkinson's that resemble treatments for autoimmune diseases," said the study's senior author, David Sulzer, PhD, professor of neurobiology in the departments of psychiatry, neurology, and pharmacology at Columbia University College of Physicians & Surgeons.
The new hypothesis about Parkinson's emerges from other findings in the study that overturn a deep-seated assumption about neurons and the immune system.
http://www.cumc.columbia.edu/
Apr 19, 2014
Dr. Krishna Kumari Challa
Differences Between Neanderthals And Modern Man Caused By Genetic Switches
With Neanderthals and modern humans sharing more than 99.8 percent of their genetic material, the differences in DNA between the two species are fairly minimal and a new study has found that the differences seen in phenotypes are mostly caused by certain genes being “switched on” or “switched off.”
According to the study published in the journal Science, genetic switches that affect the size and shape of limbs, as well as those that affect the development of the brain, are the most pronounced differences.
The study brings up the importance of researching the epigenome, or the genetic aspects that are responsible for switching on or off certain genes. Recent research has revealed how the epigenome can affect everything from cancer risk to the subtle differences between identical twins, each of whom have a copy of the same genetic material. The switching off of genes is typically achieved through a process called methylation – in which a methyl group, comprised of a carbon atom and three hydrogen atoms, is attached to a gene.
To uncover the epigenomic differences between Neanderthals and moderns humans, scientists took genetic material from limb bones of a living person, a Neanderthal and a Denisovan – an extinct Stone Age human that lived in Eurasia.
The study team was able to find approximately 2,200 regions that were triggered in today’s humans, but switched off in either or both extinct species, or the other way around. One of the main differences identified by the team was a group of five genes called HOXD, which impacts the appearance and size of limbs. It was mainly silenced in both ancient species, the scientists said. The HOXD differences could explain Neanderthals’ characteristic shorter limbs, bowleggedness and oversized hands and fingers.
Chris Stringer of the Natural History Museum in London, who was not directly involved in the study, told Reuters that the HOXD gene finding “may help to explain how these ancient humans were able to build stronger bodies, better adapted to the physical rigors of Stone Age life.”
The study team noted that the epigenome can be affected by lifestyle and environmental factors. This means that the differences observed could be unique to the individual sampled – rather than being representative on an entire species.
The researchers also found major epigenomic differences with respect to genes known to be related to neurological and psychiatric disorders such as autism and Alzheimer’s disease. These genes were silenced in the Neanderthal samples.
http://www.redorbit.com/news/science/1113124657/epigenome-neanderth...
Apr 19, 2014
Dr. Krishna Kumari Challa
A groundbreaking study published in PLOS ONE by Prof. Iris Berent of Northeastern University and researchers at Harvard Medical School shows the brains of individual speakers are sensitive to language universals. Syllables that are frequent across languages are recognized more readily than infrequent syllables. Simply put, this study shows that language universals are hardwired in the human brain.
LANGUAGE UNIVERSALS
Language universals have been the subject of intense research, but their basis remains elusive. Indeed, the similarities between human languages could result from a host of reasons that are tangential to the language system itself. Syllables like lbog, for instance, might be rare due to sheer historical forces, or because they are just harder to hear and articulate. A more interesting possibility, however, is that these facts could stem from the biology of the language system. Could the unpopularity of lbogs result from universal linguistic principles that are active in every human brain?
http://www.northeastern.edu/cos/2014/04/iris-berent/
Apr 19, 2014
Dr. Krishna Kumari Challa
Older women with gumption score high on compassion
Researchers at the University of California, San Diego School of Medicine report that older women, plucky individuals and those who have suffered a recent major loss are more likely to be compassionate toward strangers than other older adults.
The study is published in this month’s issue of the International Journal of Geriatric Psychiatry.
http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291099-1166
Apr 19, 2014
Dr. Krishna Kumari Challa
Northwestern synthetic biology team has created a new technology for modifying human cells to create programmable therapeutics that could travel the body and selectively target cancer and other sites of disease.
Engineering cell-based, biological devices that monitor and modify human physiology is a promising frontier in clinical synthetic biology. However, no existing technology enabled bioengineers to build such devices that sense a patient’s physiological state and respond in a customized fashion.
“The project addressed a key gap in the synthetic biology toolbox,” says Joshua Leonard, assistant professor of chemical and biological engineering in Northwestern’s McCormick School of Engineering and Applied Science. “There was no way to engineer cells in a manner that allowed them to sense key pieces of information about their environment, which could indicate whether the engineered cell is in healthy tissue or sitting next to a tumor.”
http://pubs.acs.org/journal/asbcd6
Apr 19, 2014
Dr. Krishna Kumari Challa
Genetic Study Tackles Slow Plant Domestication Mystery
http://www.redorbit.com/news/science/1113124568/slow-plant-domestic...
Apr 20, 2014
Dr. Krishna Kumari Challa
Apr 22, 2014
Dr. Krishna Kumari Challa
The extent to which biodiversity change in local assemblages contributes to global biodiversity loss is poorly understood. We analyzed 100 time series from biomes across Earth to ask how diversity within assemblages is changing through time. We quantified patterns of temporal α diversity, measured as change in local diversity, and temporal β diversity, measured as change in community composition. Contrary to our expectations, we did not detect systematic loss of α diversity. However, community composition changed systematically through time, in excess of predictions from null models. Heterogeneous rates of environmental change, species range shifts associated with climate change, and biotic homogenization may explain the different patterns of temporal α and β diversity. Monitoring and understanding change in species composition should be a conservation priority.
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Biodiversity Survives Extinctions for Now
A meta-analysis of ecosystems finds that species losses in any given place do not yet translate to large changes in the number of different species in that place.
http://www.scientificamerican.com/podcast/episode/biodiversity-surv...
http://www.sciencemag.org/content/344/6181/296
Apr 22, 2014
Dr. Krishna Kumari Challa
What Is the Deep Web?
The internet is huge. I'm sure many of you know that, but it's almost unbelievable that when Googling the term "cat videos" that Google can serve up nearly a billion hits from all across the web. Now keep in mind there are 7 billion people on the planet. It's mind boggling.
But what if I were to tell you that Google and other search engines can only search a fraction of the web. This number varies from source to source, but the most generous term that I've heard is that Google can search about 10% of the world wide web. So what's in the other 90%?
Well I can assure you it's probably not another billion cat videos!
http://www.quickanddirtytips.com/tech/web/what-is-the-deep-web
Apr 22, 2014
Dr. Krishna Kumari Challa
Biofuels from crop residue can reduce soil carbon and increase CO2 emissions
Biofuels made using corn waste could release 7 percent more greenhouse gases in the early years compared to conventional gasoline. As a result, this type of cellulosic ethanol could be inelligible to meet quotas under the 2007 Energy Independence and Security Act (EISA).
According to a new study published yesterday in Nature Climate Change, this type of cellulosic biofuel could result in a 7% net increase in emissions. The government-funded research states that the main cause of this increase comes down to absolute changes in soil carbon content.
The carbon content of soil is broadly a function of new inputs (plant and animal material) and losses (predominately via erosion and respiration). Conventionally, corn crop residue is left on the field after harvest in order to reduce soil erosion and maintain the carbon stocks and soil fertility.
By removing corn waste from fields, models indicate that soil carbon content will decrease over time. In turn, corn-waste ethanol will effectively produce 7% more carbon dioxide equivalent than conventional gasoline in the short-term. While the results vary according to the amount of carn residue that is removed, any removal resulted in a net increase in emissions in the model.
In the longer-term, the study says that these types of biofuels will result in a net emissions decrease. However, the short term increase is enough to keep this type of biofuel from complying with regulations in the 2007 Energy Independence and Security Act (EISA). This Act requires that biofuels produce 60% less pollution than conventional gasoline.
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2...
Apr 22, 2014
Dr. Krishna Kumari Challa
Elections 2014: Politicians told to do more for science and technology
The scientific community demands that the next government at the centre set aside a bigger chunk of the budget for research and development, create infrastructure for "continuous innovations" and boost science movements among the electorate and dovetail this with the private sector's aid.
http://gadgets.ndtv.com/science/news/election-2014-politicians-told...
Apr 22, 2014
Dr. Krishna Kumari Challa
The connection between heart attack fight and birds
A new study into how the world's highest flying bird, bar-headed geese, is able to survive at extreme altitudes may have future implications for low-oxygen medical conditions in humans. An international team of scientists recently tracked bar-headed geese while they migrated across the Himalayas. They found that these birds are able to tolerate running at top speed while breathing only 7% oxygen.
Lucy Hawkes of the University of Exeter, along with colleagues Charles Bishop (Bangor University) and Pat Butler (University of Birmingham) tested how the geese were at coping with exercise in reduced oxygen environments by simulating the conditions of Mt Everest in a clear box and then getting the birds to run as fast as possible on a treadmill inside the box. The air on the highest mountains is made up of 7% oxygen compared with 21% at sea level.
Hawkes said, "It all seems to come down to how much oxygen bar-headed geese can supply to their heart muscles. The more they supply, the faster their heart beats and keeps the supply of oxygen to the rest of the body going." He added, "The wider implications of these findings are for low-oxygen medical conditions in humans, such as heart attack and stroke — suggesting what adaptations might help prevent problems in the first place and learning how animals have managed to cope with really extreme environments."
-TNN
Apr 22, 2014
Dr. Krishna Kumari Challa
Apr 23, 2014
Dr. Krishna Kumari Challa
Antibiotics: A new spanner in the works of bacterial transcription
A promising molecular target that is unlikely to develop antibiotic resistance has been identified in bacteria.
http://elifesciences.org/content/3/e02840
Apr 23, 2014
Dr. Krishna Kumari Challa
Cow poop promotes the spread of antibiotic resistant bacteria
Manure from dairy cows has been defined as an increasing source of bacteria that can become resistant to antibiotics. These findings are the result of the work of Fabienne Wichmann and colleagues at Yale University in New Haven, Connecticut. The research was published in the April 22, 2014, edition of the journal mBio®.
Bacteria that are antibiotic resistant reach the food chain of humans through the use of cow manure as fertilizer. The manure may or may not contain bacteria that are antibiotic resistant. If the manure does contain an antibiotic resistant strain of bacteria then there is a potential for transmission to humans that eat food that was fertilized with cow manure. The food plants can even become a source of antibiotic resistance due to the phenomenon of gene exchange between species.
A more prominent and more likely transfer of new antibiotic bacterial species to humans is through infection of cow farmers by new bacterial strains. The dairy cow farmers can transmit a new disease directly to other humans through physical contact or through airborne distribution during coughing or sneezing. The more humans that come into contact with a potentially antibiotic resistant type of bacteria increases the probability that the bacteria will become resistant to antibiotics due in part to the high level of use of antibiotics by humans.
The researchers found that only five samples of cow manure contained 80 unique and functional antibiotic resistance genes. The scientists created a laboratory cultured strain of Escherichia coli that was resistant to one of the four major types of antibiotics used to treat humans from the 80 genes. The scientists also found a never before known family of antibiotic resistant genes that conferred resistance to the same group of antibiotics.
A primary source of antibiotic resistant bacteria origination is the use of antibiotics to keep cattle healthy. The potential for transfer of antibiotic resistance to humans through food crops depends on whether the cow manure has antibiotic resistant bacteria or genes. It is possible that a new antibiotic resistant disease could be contracted by people simply by using cow manure as fertilizer for their house plants or home garden.
Source: http://www.examiner.com/article/cow-poop-promotes-the-spread-of-ant...
Apr 23, 2014
Dr. Krishna Kumari Challa
Citizen scientists pitch new uses for paper microscope
Ten thousand ‘print-and-fold’ paper microscopes initially designed as low-cost medical diagnostic tools are being given away to researchers and citizen scientists who come up with novel ways to use them to test their ideas.
The goal of the Ten Thousand Microscopes initiative, funded by the Gordon and Betty Moore Foundation, is to create a crowdsourced lab manual for Foldscope, the low-cost microscope launched earlier this year by a US bioengineering team that combines pragmatic, origami design with sophisticated micro-optics.
The idea is to make “microscopy for everyone”, says Manu Prakash, a bioengineering researcher at Stanford University, United States, who led the development of the frugal innovation to address the lack of cheap, easy-to-use diagnostic tools for diseases in remote and impoverished communities.
http://www.scidev.net/global/biotechnology/news/citizen-scientists-...
Apr 23, 2014
Dr. Krishna Kumari Challa
Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
Researchers from Singapore and Germany have found a new way to study the curious properties observed at the interface of materials.
An international team led by researchers at the National University of Singapore (NUS) has developed a technique to study the interface between materials, shedding light on the curious properties that arise when two materials are put together.
Studying material interfaces is part of a research area known as condensed matter physics. When matter is condensed, mutual interactions between particles alters physical behavior, giving rise to exotic properties. A better understanding of how materials interface allows scientists to tweak material properties to possibly develop better solar cells, superconductors and smaller hard drives.
“If you put two materials together, you can create completely new properties. For instance, two non-conducting, non-magnetic insulators can become conducting and in some cases ferromagnetic and superconducting at their interface,” explains NUS Assistant Professor Andrivo Rusydi, who led the research.
The team investigated the electrical conductivity of strontium titanate and lanthanum aluminate, two insulators that become conductors at their interface. They observed that conductivity was ten-fold less than what was predicted theoretically, meaning that 90 percent of the expected electrons were missing.
To find the missing electrons, the team used high-energy reflectivity and spectroscopic ellipsometry experiments which flooded the interface with a wide range of energy. This revealed electrons that were bound within the molecular lattice, which prevented them from moving and explained the observed low conductivity.
The team’s new approach and insights, which culminated in a recent publication with Nature Communications, will be used for further investigations on the basic interface characteristics among materials.
http://www.nature.com/ncomms/2014/140414/ncomms4663/full/ncomms4663...
Apr 23, 2014
Dr. Krishna Kumari Challa
Research at the University of Adelaide has shed new light onto the possible causes of sudden infant death syndrome (SIDS), which could help to prevent future loss of children’s lives.
Researchers in the University’s School of Medical Sciences have found that telltale signs in the brains of babies that have died of SIDS are remarkably similar to those of children who died of accidental asphyxiation.
'β-Amyloid precursor protein staining of the brain in sudden infant and early childhood death'
http://onlinelibrary.wiley.com/doi/10.1111/nan.12109/abstract;jsess...
Apr 23, 2014
Dr. Krishna Kumari Challa
Parts of Antarctica, one of the coldest places on Earth, were as warm as today's California coast about 40 million years ago with temperatures as high as 17 degrees Celsius, a new study has found.
Researchers also found that the polar regions of the southern Pacific Ocean once registered 21st-century Florida heat.
The findings underscore the potential for increased warmth at Earth's poles and the associated risk of melting polar ice and rising sea levels, the researchers said.
Led by scientists at Yale University, the study focused on Antarctica during the Eocene epoch, 40-50 million years ago, a period with high concentrations of atmospheric CO2 and consequently a greenhouse climate.
Today, Antarctica is year-round one of the coldest places on Earth, and the continent's interior is the coldest place, with annual average land temperatures far below zero degrees Fahrenheit.
The new measurements can help improve climate models used for predicting future climate, according to co-author Hagit Affek, associate professor of geology & geophysics at Yale.
-PTI
Apr 23, 2014
Dr. Krishna Kumari Challa
Agenetic disease has been cured in living, adult animals for the first time using a revolutionary genome-editing technique that can make the smallest changes to the vast database of the DNA molecule with pinpoint accuracy.
Scientists have used the genome-editing technology to cure adult laboratory mice of an inherited liver disease by correcting a single "letter" of the genetic alphabet which had been mutated in a vital gene involved in liver metabolism. A similar mutation in the same gene causes the equivalent inherited liver disease in humans — and the successful repair of the genetic defect in laboratory mice raises hopes that the first clinical trials on patients could begin within a few years, scientists said.
The success is the latest achievement in the field of genome editing. This has been transformed by the discovery of Crispr, a technology that allows scientists to make almost any DNA changes at precisely defined points on the chromosomes of animals or plants.
Crispr — pronounced "crisper" — was initially discovered in 1987 as an immune defence used by bacteria against invading viruses. Its powerful genome-editing potential in higher animals, including humans, was only fully realised in 2012 and 2013 when scientists showed that it can be combined with a DNAsniping enzyme called Cas9 and used to edit the human genome . Since then there has been an explosion of interest in the technology because it is such a simple method of changing the individual letters of the human genome — the 3 billion "base pairs" of the DNA molecule — with an accuracy equivalent to correcting a single misspelt word in a 23-volume encyclopaedia.
In the latest study, scientists at the Massachusetts Institute of Technology (MIT) used Crispr to locate and correct the single mutated DNA base pair in a liver gene known as LAH, which can lead to a fatal build-up of the amino acid tyrosine in humans and has to be treated with drugs and a special diet. The researchers effectively cured mice suffering from the disease by altering the genetic make-up of about a third of their liver cells using the Crispr technique, which was delivered by high-pressure intravenous injections.
"We basically showed you could use the Crispr system in an animal to cure a genetic disease, and the one we picked was a disease in the liver which is very similar to one found in humans," said professor Daniel Anderson of MIT, who led the study.
"The disease is caused by a single point mutation and we showed that the Crispr system can be delivered in an adult animal and result in a cure. We think it's an important proof of principle that this technology can be applied to animals to cure disease," Anderson said. "The fundamental advantage is that you are repairing the defect , you are actually correcting the DNA itself," he said. "What is exciting about this approach is that we can actually correct a defective gene in a living adult animal."
Jennifer Doudna, of the University of California, Berkeley , who was one of the codiscoverers of the Crispr technique , said professor Anderson's study is a "fantastic advance" because it demonstrates that it is possible to cure adult animals living with a genetic disorder.
"Obviously there would be numerous hurdles before such an approach could be used in people, but the simplicity of the approach, and the fact that it worked, really are very exciting," professor Doudna said. "I think there will be a lot of progress made in the coming one to two years in using this approach for therapeutics and other real-world applications," she added.
''Scientists ‘edit’ DNA to correct adult genes and cure diseases ''
http://www.independent.co.uk/news/science/revealed-scientists-edit-...
Apr 23, 2014
Dr. Krishna Kumari Challa
Apr 25, 2014
Dr. Krishna Kumari Challa
Risk factors for food allergy.
The dual-allergen exposure hypothesis is the theory that exposure to food allergens through the skin can lead to allergy, while consumption of these foods at an early age may actually result in tolerance. Depending on the balance of these exposures, either tolerance or allergy will “win.” Children with eczema, for example, have a disrupted skin barrier that could allow exposure to food proteins in the environment – such as peanut oil in creams or peanut residue on tables. Under the hypothesis, if these children avoid peanuts but are still exposed to them in the environment, they might be more likely to develop peanut allergy.
http://blogs.scientificamerican.com/food-matters/2014/04/23/prevent...
Despite efforts to prevent food allergy (FA) in children, IgE-mediated FAs are increasing in westernized countries. Previous preventive strategies, such as prolonged exclusive breast-feeding and delayed weaning onto solid foods, have recently been called into question. The present review considers possible risk factors and theories for the development of FA. An alternative hypothesis is proposed, suggesting that early cutaneous exposure to food protein through a disrupted skin barrier leads to allergic sensitization and that early oral exposure to food allergen induces tolerance. Novel interventional strategies to prevent the development of FA are also discussed.
http://www.ncbi.nlm.nih.gov/pubmed/22464642
Apr 25, 2014
Dr. Krishna Kumari Challa
Animal Kingdom Communication
UM researcher discovers the most effective animal signal strategies.
There are all sorts of signaling strategies in nature. Peacocks puff out their feathers and spread their colorful tails; satin bowbirds build specialized stick structures, called bowers, and decorate them with blue and shiny objects; and European bitterling males show off bright nuptial coloration during spawning season. Each species has evolved a unique method to communicate with others.
“Signaling can have profound fitness implications for individuals that are either signaling or receiving the signal,” says Gavin M. Leighton, author of a new study on the effectiveness of signaling systems.
“For instance, individuals may signal to attract mates, or they may signal to rivals in order to defend a territory. Additionally, many biological models of cooperative behavior require individuals to signal how cooperative they were in past interactions.”
Effective communication is not just about the signaler, according to the study, the receiver also needs to assess the signaler efficiently. For instance, one of the most effective strategies from the perspective of female birds is assessing groups of males called leks, where females can assess multiple males in a short period of time.
“When receivers had to assess individual signalers one at a time, the accuracy of their ranking of signalers decreased compared to when all the signalers could be observed simultaneously.”
The study also shows that individuals that used non-food items, like a twig, in their signaling display had the least effective strategy. Surprisingly, individuals that invest in ecological structures, such as building a nest, improved the ability of the females to rank signalers, but the effect was fairly weak.
“The most unexpected finding was that investing in some sort of temporally stable structure only weakly improved the ability for receivers to assess signalers,” Leighton, said. “I originally suspected that investing in a structure would allow individuals to quickly convey their signaling effort over time in a single, observable feature. While I did find that structures helped, the effect was not as strong as other the other variables.”
In order to investigate specific characteristics of systems and provide the ranking of signalers by receivers, Leighton designed a computer model that represents salient features of many signaling systems, across a variety of scenarios. The model is called an agent-based model. It allows the researcher to program individual entities with specified behaviors. Then, the software provides the ranking information to the researcher. Included in the analyses were different species of birds, fishes and insects.
“The study systematically models a series of behavioral and ecological conditions. To the best of my knowledge no one has performed a general analysis of these different types of signaling systems.”
The study assumes that in every scenario individuals had perfect memory. In other words, when a receiver saw a signaling individual, they were able to unambiguously assign this effort to a specific individual. In nature, individuals probably make errors in assigning signaling effort or forget the effort of individuals over time.
“By itself, this seems like an unwarranted assumption, however, it is not easy to compare across signaling systems where memory also varies with the species in question,” Leighton says.
In the future, the researcher would like to include variation in the memory of individual receivers in these models. “There may be effects of imperfect memory that influence signaling effectiveness and I think this would be a good next step.”
http://www.miami.edu/index.php/news/releases/animal_kingdom_communi...
Apr 25, 2014
Dr. Krishna Kumari Challa
Virus-Inspired Coating Protects DNA Nanostructures In The Body
Nanomedicine: A lipid coating could protect DNA drug carriers in the bloodstream
Nanomedicines made from self-assembling DNA structures could last longer inside the bloodstream with a lipid bilayer coating similar to the ones worn by some viruses (ACS Nano 2014, DOI: 10.1021/nn5011914). This protection strategy could make it possible to test new kinds of DNA nanotherapies in animals and bring them to the clinic, the developers say.
DNA is a versatile building block for making nanoparticles with precise shapes that can perform complex tasks. For example, in 2012, researchers used DNA to fashion a drug-carrying box with two locks made from DNA; the box opens to release the drug only if both locks are bound to certain proteins on a target cell (Science, DOI: 10.1126/science.1214081). But researchers struggle to test this and other DNA nanotechnology in animals. Any free-floating DNA in the bloodstream is rapidly destroyed by enzymes. Researchers haven’t yet figured out how to package these DNA machines so that they can survive long enough in the body to do their work.
To solve this problem, William M. Shih, a synthetic biologist at Harvard University, looked to nature for inspiration. Viruses, which are essentially groups of genes that use living cells to replicate, have already developed strategies to endure in the bloodstream. One is to coat themselves with a protective lipid bilayer.
Shih decided to mimic this strategy. He first designed a simple octahedron-shaped wireframe of DNA using software his group had previously developed. Given the dimensions of a structure, this software generates a recipe list of DNA strands that will self-assemble into the desired shape. A DNA synthesis company makes the strands, and the researchers mix them in the lab.
Each strut in the DNA octahedron is made up of six 28-nm-long double helices held together by shorter strands. The Harvard group created attachment points on the interior and exterior surfaces of the octahedron using single-stranded pieces of DNA. On the interior, these handles bind to complementary DNA strands that carry fluorescent dyes so that the scientists could track the particles in animals. The exterior handles bind to complementary strands carrying lipids.
This created a 50-nm-diameter DNA octahedron with “greasy plugs” on it, Shih says. “Then we take this hairball and mix it with a solution of giant liposomes in surfactant.” The lipids from the liposomes stick to the plugs, eventually creating a continuous coating on the DNA frame. The completed structure is about 70 to 80 nm in diameter.
http://cen.acs.org/articles/92/web/2014/04/Virus-Inspired-Coating-P...
Apr 25, 2014
Dr. Krishna Kumari Challa
Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, have developed a design structure for composite materials that is more impact resistant and tougher than the standard used in airplanes.
Apr 25, 2014
Dr. Krishna Kumari Challa
Neuroscientists Discover Brain Circuits Involved in Emotion
Neuroscientists have discovered a brain pathway that underlies the emotional behaviours critical for survival.
New research by the University of Bristol, published in the Journal of Physiology today [23 April], has identified a chain of neural connections which links central survival circuits to the spinal cord, causing the body to freeze when experiencing fear.
Understanding how these central neural pathways work is a fundamental step towards developing effective treatments for emotional disorders such as anxiety, panic attacks and phobias.
An important brain region responsible for how humans and animals respond to danger is known as the PAG (periaqueductal grey), and it can trigger responses such as freezing, a high heart rate, increase in blood pressure and the desire for flight or fight.
This latest research has discovered a brain pathway leading from the PAG to a highly localised part of the cerebellum, called the pyramis. The research went on to show that the pyramis is involved in generating freezing behaviour when central survival networks are activated during innate and learnt threatening situations.
The pyramis may therefore serve as an important point of convergence for different survival networks in order to react to an emotionally challenging situation.
-Journal of Physiology
Apr 25, 2014
Dr. Krishna Kumari Challa
Royal Statistical Society looking for volunteer scientists
Date: 22 Apr 2014
The Royal Statistical Society (RSS) is looking for volunteer scientists to take part in their programme of delivering science and statistics training to journalists.
Volunteers attend a ‘train the trainer’ workshop before signing up to deliver sessions at news outlets and journalism schools throughout the UK. Having successfully run the course for three years, the RSS is looking to widen their pool of volunteers.
Anyone interested in taking part should contact Vinet Campbell, National Coordinator for Science Journalism Training at V.Campbell@rss.org.uk. More information can also be found at their website.
http://www.statslife.org.uk/resources/for-journalists
Apr 25, 2014
Dr. Krishna Kumari Challa
Breakthrough harnesses light for controlled chemical reaction
When chemist Tehshik Yoon looks out his office window, he sees a source of energy to drive chemical reactions. Plants "learned" to synthesize chemicals with sunlight eons ago; Yoon came to the field a bit more recently. But this week, in the journal Science, he and three collaborators detail a way to use sunlight and two catalysts to create molecules that are difficult to make with conventional techniques.
In chemistry, heat and ultraviolet (UV) light are commonly used to drive reactions. Although light can power reactions that heat cannot, UV has disadvantages, says Yoon, a chemistry professor at University of Wisconsin-Madison. The UV often used in industry carries so much energy that "it's dangerous to use, unselective, and prone to making unwanted by-products."
Many chemicals exist in two forms that are mirror images of each other, and Yoon is interested in reactions that make only one of those images.
"It's like your hands," Yoon says. "They are similar, but not identical; a left-hand glove does not fit the right hand. It's the same way with molecules in biology; many fail unless they have the correct 'handedness,' or 'chirality.'"
The pharmaceutical industry, in particular, is concerned about controlling chirality in drugs, but making those shapes is a hit-or-miss proposition with UV light, Yoon says.
He says the new technique answers a question posed by a French chemist in 1874, who suggested using light to make products with controlled chirality. "Chemists could never do that efficiently, and so the prejudice was that it was too difficult to do."
- University of Wisconsin-Madison
Apr 25, 2014
Dr. Krishna Kumari Challa
Ocean microbes display remarkable genetic diversity
Scientists in MIT's Department of Civil and Environmental Engineering (CEE) recently performed a cell-by-cell genomic analysis on a wild population of Prochlorococcus living in a milliliter -- less than a quarter teaspoon -- of ocean water, and found hundreds of distinct genetic subpopulations.
- Massachusetts Institute of Technology
Apr 25, 2014