Implantable wireless devices trigger -- and may block -- pain signals

Implanted microLED devices light up, activating peripheral nerve cells in mice. The devices are being developed and studied by researchers at Washington University School of Medicine in St. Louis and the University of Illinois at Urbana-Champaign as a potential treatment for pain that does not respond to other therapies.

Building on wireless technology that has the potential to interfere with pain, scientists have developed flexible, implantable devices that can activate -- and, in theory, block -- pain signals in the body and spinal cord before those signals reach the brain.

The researchers, at Washington University School of Medicine in St. Louis and the University of Illinois at Urbana-Champaign, said the implants one day may be used in different parts of the body to fight pain that doesn't respond to other therapies.

"Our eventual goal is to use this technology to treat pain in very specific locations by providing a kind of 'switch' to turn off the pain signals long before they reach the brain," said co-senior investigator Robert W. Gereau IV, PhD, the Dr. Seymour and Rose T. Brown Professor of Anesthesiology and director of the Washington University Pain Center.

The study is published online Nov. 9 in the journal Nature Biotechnology.

Because the devices are soft and stretchable, they can be implanted into parts of the body that move, Gereau explained. The devices previously developed by the scientists had to be anchored to bone.

"But when we're studying neurons in the spinal cord or in other areas outside of the central nervous system, we need stretchable implants that don't require anchoring," he said.

The new devices are held in place with sutures. Like the previous models, they contain microLED lights that can activate specific nerve cells. Gereau said he hopes to use the implants to blunt pain signals in patients who have pain that cannot be managed with standard therapies.

The researchers experimented with mice that were genetically engineered to have light-sensitive proteins on some of their nerve cells. To demonstrate that the implants could influence the pain pathway in nerve cells, the researchers activated a pain response with light. When the mice walked through a specific area in a maze, the implanted devices lit up and caused the mice to feel discomfort. Upon leaving that part of the maze, the devices turned off, and the discomfort dissipated. As a result, the animals quickly learned to avoid that part of the maze.

The experiment would have been very difficult with older optogenetic devices, which are tethered to a power source and can inhibit the movement of the mice.

Because the new, smaller, devices are flexible and can be held in place with sutures, they also may have potential uses in or around the bladder, stomach, intestines, heart or other organs, according to co-principal investigator John A. Rogers, PhD, professor of materials science and engineering at the University of Illinois.

"They provide unique, biocompatible platforms for wireless delivery of light to virtually any targeted organ in the body," he said.

Rogers and Gereau designed the implants with an eye toward manufacturing processes that would allow for mass production so the devices could be available to other researchers. Gereau, Rogers and Michael R. Bruchas, PhD, associate professor of anesthesiology at Washington University, have launched a company called NeuroLux to aid in that goal.

Source :  Washington University School of Medicine

An arms race among venomous animals?

This is an Anderson's Pitviper (Trimeresurus Andersoni), a highly venomous snake, photographed by Dr. Kartik Sunagar in the Andaman Islands of India.

In a new study published in the journalPLOS Genetics, scientists at the Hebrew University of Jerusalem have revealed new discoveries about how animal venom evolves.

Venom is a complex mixture of proteins and other toxic chemicals produced by animals such as snakes and spiders, either to incapacitate their prey or to defend against predators. The influence of positive selection (the process by which a protein changes rapidly over evolutionary time scales) in expanding and diversifying animal venoms is widely recognized.

This process was hypothesized to result from an evolutionary chemical arms race, in which the invention of potent venom in the predatory animals and the evolution of venom resistance in their prey animals, exert reciprocal selection pressures.

In contrast to positive selection, the role of purifying selection (also known as negative selection, which is the selective removal of deleterious genetic changes from a population) has rarely been considered in venom evolution.

Moreover, venom research has mostly neglected ancient animal groups in favor of focusing on venomous snakes and cone snails, which are both "young" animal groups that originated only recently in evolutionary timescales, approximately 50 million years ago. Consequently, it was concluded that venom evolution is mostly driven by positive selection.

In the new study, Dr. Yehu Moran at the Hebrew University's Department of Ecology, Evolution and Behavior and the guest scientist Dr. Kartik Sunagar examined numerous venom genes in different animals in order to unravel the unique evolutionary strategies of toxin gene families.

The researchers analyzed and compared the evolutionary patterns of over 3500 toxin sequences from 85 gene families. These toxins spanned the breadth of the animal kingdom, including ancient venomous groups such as centipedes, scorpions, spiders, coleoids (octopus, cuttlefish and squids) and cnidarians (jellyfish, sea anemones and hydras).

Unexpectedly, despite their long evolutionary histories, ancient animal groups were found to have only accumulated low variation in their toxins.

The analysis also revealed a striking contrast between the evolution of venom in ancient animal groups as compared to evolutionarily "young" animals. It also highlighted the significant role played by purifying selection in shaping the composition of venoms.

According to Dr. Yehu Moran, "Our research shows that while the venoms of ancient lineages evolve more slowly through purifying selection, the venoms in more recent lineages diversify rapidly under the influence of positive selection."

The findings enable the postulation of a new theory of venom evolution. According to this theory, toxin-producing genes in young venomous groups that enter a novel ecological niche, experience a strong influence of positive selection that diversifies their toxins, thus increasing their chances to efficiently paralyze relevant prey and predatory species in the new environment.

However, in the case of the ancient venomous groups, where the venom is already "optimized" and highly suitable for the ecological niche, the venom's rate of accumulating variations slows down under the influence of purifying selection, which preserves the potent toxins generated previously.

The proposed "two-speed" mode of venom evolution highlights the fascinating evolutionary dynamics of this complex biochemical cocktail, by showing for the first time the significant roles played by different forces of natural selection in shaping animal venoms.

According to Drs. Moran and Sunagar, "The 'two-speed' mode of evolution of animal venoms involves an initial period of expansion, resulting in the rapid diversification of the venom arsenal, followed by longer periods of purifying selection that preserve the now potent toxin pharmacopeia. However, species that have entered the stage of purification and fixation may re-enter the period of expansion if they experience a major shift in ecology and/or environment."

Source : Journal PLOS Genetics (http://dx.doi.org/10.1371/journal.pgen.1005596)

First-of-its-kind study of puberty timing in men

In the largest genomic analysis of puberty timing in men, new research conducted by scientists at the University of Cambridge and 23andMe* shows that the timing of puberty in males and females is influenced by many of the same-shared genetic factors. The study results are the first to quantify the strongly shared genetic basis for puberty timing between the sexes.

Published this week in Nature Communications, the study is the largest genomic analysis of puberty to look at both men and women. Previous work had identified 106 genetic variants that alter puberty timing in females, and the current study shows that those same genetic factors have very similar effects on male puberty timing. The study looked at genetic information of more than 55,000 male 23andMe customers who consented to participate in research. Following this first analysis, the collected data was compared to existing data from more than 250,000 women. The study focused on the genetic regions that influence age at voice breaking - a distinct developmental milestone that happens to young men as their larynx (voice box) lengthens when exposed to male hormones.

"Our study shows that although there are obvious physical differences in pubertal development between boys and girls, many of the underlying biological processes governing it are the same. It also shows that the age when men's voices break, even when recalled decades after the event, is an informative measure of puberty timing," says co-author Dr. Felix Day from the MRC Epidemiology Unit at the University of Cambridge.

"Until now, most of our understanding of the biological regulation of puberty timing has come from large studies of healthy women, in whom the stages of puberty are usually easier to remember, or studies of patients affected by rare disorders. Research has been scarce in men, largely because investigators have disregarded the accuracy that men can recall pubertal events," explains study lead Dr. John Perry (also from the MRC Epidemiology Unit at the University of Cambridge).

In addition, the study finds five new genetic variants associated with puberty timing, some acting through known hormone pathways, others through previously overlooked hormone pathways.

One of the main aims of this study was to look at the relevance of male puberty timing in impacting health and the development of diseases. The study found that many of the genes involved in puberty timing were also shared with diseases that appear later in life. For most diseases, earlier puberty appeared genetically linked to poorer health outcomes.

Co-lead Dr. Ken Ong (also from the MRC Epidemiology Unit at the University of Cambridge) concludes, "There was already good evidence in women that earlier puberty timing leads to higher risks for health outcomes later in life such as Type 2 diabetes, obesity and cardiovascular disease. We now show that the same is true in men. The next steps will be to understand how to prevent early puberty in boys and girls, possibly by reducing childhood overweight and obesity, or by other means."

Source : Nature Communications (http://dx.doi.org/10.1038/ncomms9842)

Meat -- and how it's cooked -- may impact kidney cancer risk

A new study indicates that a meat-rich diet may increase the risk of developing kidney cancer through mechanisms related to particular cooking compounds. Also, these associations may be modified by genetic susceptibility to kidney cancer. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the study illustrates how diet and genetics may interact to impact cancer risk.

The incidence of renal cell carcinoma (RCC), the most common form of kidney cancer in adults, has been increasing in the United States and other developed nations. Investigators suspect that factors related to a western lifestyle--such as a diet high in meats, processed foods, and starches--may play an important role in this trend. To investigate, a team led by Xifeng Wu, MD, PhD, of The University of Texas MD Anderson Cancer Center in Houston, studied the dietary intake and genetic risk factors of 659 patients newly diagnosed with RCC and 699 healthy controls.

The researchers found that kidney cancer patients consumed more red and white meat compared with cancer-free individuals. Also, cancer patients consumed more cancer-causing chemicals that are produced when meat is cooked at high temperatures or over an open flame (particularly pan-frying or barbequing). Finally, the investigators discovered that individuals with certain genetic variants were more susceptible to the harmful effects of these cancer-causing chemicals.

"Our study provides additional evidence for the role of red meat, white meat, and 2-amino-1-methyl-6-phenyl-imidazo(4,5-b)pyridine (PhIP) in RCC etiology and is the first study of dietary intake of mutagenic compounds and RCC risk to suggest an association with 2-amino-3,8-dimethylimidazo(4,5-f) quinoxaline (MeIQx), one of the most abundant heterocyclic amines commonly created in grilling, barbequing, and pan-frying meats at high temperatures," said Dr. Wu. "Also, our study is the first to evaluate the impact of RCC susceptibility variants, identified via genome-wide association studies, on the association between intake of mutagenic compounds and RCC risk."

While the study was small and limited to non-Hispanic whites, the findings suggest that reducing consumption of meat, especially when cooked at high temperatures or over an open flame, might serve as a public health intervention to reduce the risk of developing RCC. In addition, genetic testing might help to identify individuals at especially high risk.

Source : Journal CANCER (http://dx.doi.org/10.1002/cncr.29543)

Energy drink increases blood pressure, norepinephrine levels

Anna Svatikova, M.D., Ph.D., of the Mayo Clinic, Rochester, Minn., and colleagues randomly assigned 25 healthy volunteers (age 18 years or older) to consume a can (480 mL; 16 fl. oz.) of a commercially available energy drink (Rockstar; Rockstar Inc) and placebo drink within 5 minutes, in random order on 2 separate days, maximum 2 weeks apart. The placebo drink, selected to match the nutritional constituents of the energy drink, was similar in taste, texture, and color but lacked caffeine and other stimulants of the energy drink (240 mg of caffeine, 2,000 mg of taurine, and extracts of guarana seed, ginseng root, and milk thistle). This JAMA study is being released to coincide with its presentation at the American Heart Association's Scientific Sessions 2015.

Energy drink consumption has been associated with serious cardiovascular events, possibly related to caffeine and other stimulants. The researchers examined the effect of energy drink consumption on hemodynamic changes, such as blood pressure and heart rate. Participants were fasting and abstained from caffeine and alcohol 24 hours prior to each study day. Serum levels of caffeine, plasma glucose, and norepinephrine (noradrenaline) were measured and blood pressure and heart rate were obtained at baseline and 30 minutes after drink ingestion.

Caffeine levels remained unchanged after the placebo drink, but increased significantly after energy drink consumption. Consumption of the energy drink elicited a 6.2 percent increase in systolic blood pressure; diastolic blood pressure increased by 6.8 percent; average blood pressure increased after consumption of the energy drink by 6.4 percent. There was no significant difference in heart rate increase between the 2 groups. The average norepinephrine level increased from 150 pg/mL to 250 pg/mL after consumption of the energy drink and from 140 pg/mL to 179 pg/mL after placebo (change rate: 74 percent vs 31 percent, respectively).

"These acute hemodynamic and adrenergic changes may predispose to increased cardiovascular risk," the authors write. "Further research in larger studies is needed to assess whether the observed acute changes are likely to increase cardiovascular risk."

Source : JAMA (http://dx.doi.org/10.1001/jama.2015.13744)

Research reveals main reasons why people go to work when ill

High job demands, stress and job insecurity are among the main reasons why people go to work when they are ill, according to new research by an academic at the University of East Anglia (UEA).

The study aims to improve understanding of the key causes of employees going to work when sick, known as presenteeism, and to help make managers more aware of the existence of the growing phenomenon, what triggers the behaviour and what can be done to improve employees' health and productivity.

A key finding of the study, published today in the Journal of Occupational Health Psychology, is that presenteeism not only stems from ill health and stress, but from raised motivation, for example high job satisfaction and a strong sense of commitment to the organisation. This may motivate people to 'go the extra-mile', causing them to work more intensively, even when sick.

One of the significant links to presenteeism is the severity of organisational policies used to monitor or reduce staff absence, such as strict trigger points for disciplinary action, job insecurity, limited paid sick leave, or few absence days allowed without a medical certificate.

Lead author Dr Mariella Miraglia, a lecturer in organisational behaviour at UEA's Norwich Business School, argues that presenteeism is associated with work and personal factors, not just medical conditions. Also, that these factors are more strongly related to, and so more able to predict, presenteeism than absenteeism.

In previous research presenteeism has been associated with both negative and positive effects on employee productivity and welfare, with contradictory causes and consequences for individuals and organisations. It has been linked to errors, lower performance, exacerbating health problems and affecting wellbeing, with more productivity loss than absenteeism. The Centre for Mental Health calculated that presenteeism from mental ill health alone costs the UK economy £15.1 billion a year.

"This study sheds light on the controversial act of presenteeism, uncovering both positive and negative underlying processes," said Dr Miraglia, who worked with Dr Gary Johns of Concordia University in Montreal, Canada. "It demonstrates that presenteeism is associated with work features and personal characteristics and not only dictated by medical conditions, in contrast to the main perspective of occupational medicine and epidemiology.

"Working while ill can compound the effects of the initial illness and result in negative job attitudes and withdrawal from work. However, the possible negative consequences of being absent can prompt employees to show up ill or to return to work when not totally recovered. Organisations may want to carefully review attendance policies for features which could decrease absence at the cost of increased presenteeism."

The research analysed data from 61 previous studies involving more than 175,960 participants, including the European Working Conditions Survey which sampled employees from 34 countries. Dr Miraglia developed an analytical model to identify the most significant causes of presenteeism and absenteeism, with work and personal characteristics relating differently to presenteeism depending on whether they followed a 'health impairment' or 'attitudinal/motivational' path.

Job demands, such as workload, understaffing, overtime and time pressure, along with difficulty of finding cover and personal financial difficulties, were found to be key reasons why people might not take a day off. Conflict between work and family, and vice versa, and being exposed to harassment, abuse, and discrimination at work were also positively related to presenteeism. This is because these negative experiences can exacerbate stress and harm health, requiring employees to choose between going to work and staying away.

Those who had a supportive work environment, for example supportive colleagues and a good relationship with managers, felt they did not have to go to work when ill, and were both more satisfied with their jobs and healthier. Optimism was linked to presenteesim, in that those with a positive outlook were more willing to carry on with their work while ill.

"Because presenteeism is more predictable than absenteeism, it is easy to modify by management actions," said Dr Miraglia. "Workplace wellness and health programmes may be desirable to reduce stress and work-related illness. Furthermore, although increasing job resources, such as job control and colleague, supervisor, and organisational support, can be helpful in tackling presenteeism through their positive impact on health, our results suggest that controlling job demands represents a key line of defence against the behaviour.

"Organisations may benefit from well-designed jobs that limit the level of demands to which employees are exposed to every day, for example by reducing excessive workload, time pressure and overtime work, as well as making sure they have the resources they need."

Dr Miraglia said further research was needed to understand when going to work while ill could be a "sustainable" and positive choice, for example in the case of a gradual recovery from long-term sickness, to improve self-esteem in the face of chronic illness or being an example of citizenship behaviour.

"It could be a good thing for some people, a way of integrating back into work again," she added. "But it would depend how much the individual and organisation wanted it and were prepared to be flexible, for example by modifying job descriptions or offering flexy time."

Source :  Journal of Occupational Health Psychology (http://dx.doi.org/10.1037/ocp0000015), University of East Anglia

The No. 1 killer is invisible to most women

Even though heart disease and stroke are the No. 1 killer of women in the U.S., most women say they don't have a personal connection to cardiovascular disease, according to research presented at the American Heart Association's Scientific Sessions 2015.

A 2014 nationally representative survey of 1,011 adult women found that those who know another woman with heart disease are 25 percent more likely to be concerned about it for themselves and 19 percent more likely to bring up heart health with their doctors. The survey was developed and conducted by the Women's Heart Alliance.

"Since women who report knowing another woman with heart disease are more apt to express concern and importantly -- bring up this issue with their doctor -- awareness of heart disease is crucial," said lead author C. Noel Bairey Merz, M.D., director of the Barbra Streisand Women's Heart Center and professor of medicine at Cedars-Sinai Medical Center in Los Angeles, California.

Yet, only 27 percent of women can name a woman in their lives with heart disease and only 11 percent can name a woman who has died from heart disease. Among those age 25 to 49, about 23 percent know a woman with heart disease, compared to 37 percent of women aged 50 to 60.

In addition, the survey found that healthcare providers more often focused on a woman's weight rather than other cardiovascular disease risk factors, compared to men who were more likely to be told their cholesterol or blood pressure is too high by their doctors.

"We are stalled on women's awareness of heart disease, partly because women say they put off going to the doctor until they've lost a few pounds. This is clearly a gendered issue," Bairey Merz said.

The survey underscores the disconnect most women experience between the widespread nature of women's heart disease and their personal perceptions.

One in three women die from heart disease and stroke in the U.S. every year. Although heart disease and stroke death rates among men have dropped steadily over the last 25 years, women's rates have fallen at a much slower rate.

Professional surveyors questioned a random sampling of women ages 25 to 60 across the country. The survey covered about 97 percent of U.S. households and took about 15 minutes. Women answered online questions and were provided computers and internet access if unavailable. Researchers factored out the effects of age, region, race, ethnicity, education and income.

A risk calculator developed jointly by the American Heart Association and the American College of Cardiology in 2013 helps identify women at risk of heart disease.

"Women should be screened for heart disease, including finding out their atherosclerotic cardiovascular disease (ASCVD) score - also called the "A-risk score," Bairey Merz said. "This figure uses your age, sex, race, blood pressure, cholesterol levels, blood pressure medication use, diabetes status and smoking status to get a 10-year cardiovascular disease risk and a lifetime risk score."

Her advice to women: "Talk to your doctor about heart disease. Every woman 40 and older needs to get their A-risk score. If you're under 40 you still need to know your blood pressure and cholesterol," Bairey Merz said.

Source : Heart Association

France : gay men can donate their blood if they haven't sex since 12 months

France has decided to end a more than 30-year-old law that banned gay men from donating blood, a measure originally put in place to stop the spread of diseases such as HIV. Health Minister Marisol Touraine said on Wednesday discrimination against potential blood donors on the basis of sexual orientation was unacceptable because it presumed that gay men all had HIV.

After a review of the measure since 2012, Touraine opted to lift the exclusion that has been in place since 1983 and was subsequently reinforced three times. "Giving blood is a generous act that cannot be conditioned by sexual orientation," Touraine said in a speech dedicated to the issue. "On the basis of proposals that were made to me ... I have decided to put an end to the exclusion from blood donation of men that have sex with men."

Touraine said blood donation from gay men would be allowed in France from next spring and would be monitored under strict conditions already in place. Men, who will not have had any sexual relation or who had some but with only one man in the past 12 months, will be allowed to donate their blood, the French health ministry said.

Well, this law is so dumb that it is more discriminatory than the previous one. It's like saying: Dear gay, you can give blood only if you are not too gay.

Oil confirmed under Africa's oldest wildlife park Virunga: DRC govt

Seismic tests in Democratic Republic of Congo's Virunga National Park, Africa's oldest wildlife reserve which is famed for its mountain gorillas, have confirmed the presence of oil, the Congolese government said Friday. Tests carried out by British oil company Soco had returned "positive" on the presence of oil deposits, Minister of Hydrocarbons Aime Ngoy Mukena told AFP by telephone.

On the question of "whether there is an oil field" underneath the park, the study answered "yes", he said, without giving further details. The announcement was likely to reignite a heated debate within DRC over the merits of exploring for oil in the vast park, which covers some 7,800 square kilometres (3,010 square miles) of lush forest, glaciated peaks and savannah in the restive eastern province of North Kivu.
The UNESCO world heritage site reopened to tourists last year after being closed for two years because of militia violence in the region.

UNESCO has warned several times that any exploration for oil in the park would be "incompatible" with its heritage status. The Congolese government has in the past promoted prospecting for oil in Virunga as offering a chance to lift the vast country out of poverty. Critics warn, however, that the oil business would only exacerbate the armed conflicts that have torn North Kivu apart for more than two decades.
"If the government tried to exploit this oil, for us it will be death," the head of a local environmental NGO, Bantu Lukambo, told AFP.

In 2010, the government awarded several oil concessions straddling the park's boundaries, including giving "block V" to Soco, but suspended the permits following a domestic and international outcry.
London-based Soco was accused of corruption and intimidation by several NGOs—charges it denies—and a statement on the company's website said it no longer holds the licence for the block.
Soco has since been allowed to carry out tests to establish the environmental impact of possible oil exploration in the park, however, and opponents fear the government may award the licences to another company.

Queen's University professor to unveil self-levitating displays called BitDrones

An interactive swarm of flying 3D pixels (voxels) developed at Queen's University's Human Media Lab is set to revolutionize the way people interact with virtual reality. The system, called BitDrones, allows users to explore virtual 3D information by interacting with physical self-levitating building blocks.

Queen's professor Roel Vertegaal and his students are unveiling the BitDrones system on Monday, Nov. 9 at the ACM Symposium on User Interface Software and Technology in Charlotte, North Carolina. BitDrones is the first step towards creating interactive self-levitating programmable matter - materials capable of changing their 3D shape in a programmable fashion - using swarms of nano quadcopters. The work highlights many possible applications for the new technology, including real-reality 3D modeling, gaming, molecular modeling, medical imaging, robotics and online information visualization.

"BitDrones brings flying programmable matter, such as featured in the futuristic Disney movie Big Hero 6, closer to reality," says Dr. Vertegaal. "It is a first step towards allowing people to interact with virtual 3D objects as real physical objects."

Dr. Vertegaal and his team at the Human Media Lab created three types of BitDrones, each representing self-levitating displays of distinct resolutions. "PixelDrones" are equipped with one LED and a small dot matrix display. "ShapeDrones" are augmented with a light-weight mesh and a 3D printed geometric frame, and serve as building blocks for complex 3D models. "DisplayDrones" are fitted with a curved flexible high resolution touchscreen, a forward-facing video camera and Android smartphone board. All three BitDrone types are equipped with reflective markers, allowing them to be individually tracked and positioned in real time via motion capture technology. The system also tracks the user's hand motion and touch, allowing users to manipulate the voxels in space.

"We call this a Real Reality interface rather than a Virtual Reality interface. This is what distinguishes it from technologies such as Microsoft HoloLens and the Oculus Rift: you can actually touch these pixels, and see them without a headset," says Dr. Vertegaal.

Dr. Vertegaal and his team describe a number of possible applications for this technology. In one scenario, users could physically explore a file folder by touching the folder's associated PixelDrone. When the folder opens, its contents are shown by other PixelDrones flying in a horizontal wheel below it. Files in this wheel are browsed by physically swiping drones to the left or right.

Users would also be able to manipulate ShapeDrones to serve as building blocks for a real-time 3D model. Finally, the BitDrone system will allow for remote telepresence by allowing users to appear locally through a DisplayDrone with Skype. The DisplayDrone would be capable of automatically tracking and replicating all of the remote user's head movements, allowing a remote user to virtually inspect a location and making it easier for the local user to understand the remote user's actions.

While their system currently only supports dozens of comparatively large 2.5" - 5" sized drones, the team at the Human Media Lab are working to scale up their system to support thousands of drones. These future drones would measure no more than a half inch in size, allowing users to render more seamless, high resolution programmable matter.

Watch a video about BitDrones : http://www.hml.queensu.ca/bitdrones.

What makes a leader? Clues from the animal kingdom

As the American media continues to buzz over who is more or less likely to secure the Republican and Democratic nominations for U.S. President, researchers in the journalTrends in Ecology & Evolution review some interesting perspectives on the nature of leadership. The experts from a wide range of disciplines examined patterns of leadership in a set of small-scale mammalian societies, including humans and other social mammals such as elephants and meerkats.

"While previous work has typically started with the premise that leadership is somehow intrinsically different or more complex in humans than in other mammals, we started without a perceived notion about whether this should be the case," said Jennifer Smith of Mills College in Oakland, California. "By approaching this problem with an open mind and by developing comparable measures to compare vastly different societies, we revealed more similarities than previously appreciated between leadership in humans and non-humans."

Chimpanzees travel together, capuchins cooperate in fights, and spotted hyenas cooperate in hunting, but the common ways that leaders promote those collective actions has remained mysterious, Smith and her colleagues say. It wasn't clear just how much human leaders living in small-scale societies have in common with those in other mammalian societies either.

To consider this issue, a group of biologists, anthropologists, mathematicians, and psychologists gathered at the National Institute for Mathematical and Biological Synthesis. These experts reviewed the evidence for leadership in four domains--movement, food acquisition, within-group conflict mediation, and between-group interactions--to categorize patterns of leadership in five dimensions: distribution across individuals, emergence (achieved versus inherited), power, relative payoff to leadership, and generality across domains.

Despite what those ongoing presidential primaries might lead one to think, the analysis by the scientific experts finds that leadership is generally achieved as individuals gain experience, in both humans and non-humans. There are notable exceptions to this rule: leadership is inherited rather than gained through experience among spotted hyenas and the Nootka, a Native Canadian tribe on the northwest coast of North America.

In comparison to other mammal species, human leaders aren't so powerful after all. Leadership amongst other mammalian species tends to be more concentrated, with leaders that wield more power over the group.

Smith says the similarities probably reflect shared cognitive mechanisms governing dominance and subordination, alliance formation, and decision-making--humans are mammals after all. The differences may be explained in part by humans' tendency to take on more specialized roles within society.

"Even in the least complex human societies, the scale of collective action is greater and presumably more critical for survival and reproduction than in most other mammalian societies," Smith said.

The researchers now plan to further quantify the various dimensions identified in the new work. There's still plenty more to learn. "As ambitious as our task was, we have only just scraped the surface in characterizing leadership across mammalian societies and some of the most exciting aspects of the project are still yet to come as biologists and anthropologists implement our novel scheme for additional taxa and societies," Smith said.

Source : Trends in Ecology & Evolution, Smith et al.: "Leadership in Mammalian Societies: Emergence, Distribution, Power, and Payoff" http://dx.doi.org/10.1016/j.tree.2015.09.013

The largest to have existed - giant rat fossils

Archaeologists with The Australian National University (ANU) have discovered fossils of seven giant rat species on East Timor, with the largest up to 10 times the size of modern rats.

Dr Julien Louys of the ANU School of Culture, History and Language, who is helping lead the project said these are the largest known rats to have ever existed.

"They are what you would call mega-fauna. The biggest one is about five kilos, the size of a small dog," Dr Louys said.

"Just to put that in perspective, a large modern rat would be about half a kilo."

The work is part of the From Sunda to Sahul project which is looking at the earliest human movement through Southeast Asia. Researchers are now trying to work out exactly what caused the rats to die out.

Dr Louys said the earliest records of humans on East Timor date to around 46,000 years ago, and they lived with the rats for thousands of years.

"We know they're eating the giant rats because we have found bones with cut and burn marks," he said.

"The funny thing is that they are co-existing up until about a thousand years ago. The reason we think they became extinct is because that was when metal tools started to be introduced in Timor, people could start to clear forests at a much larger scale."

Dr Louys said the project team is hoping to get an idea of when humans first moved through the islands of Southeast Asia, how they were doing it and what impact they had on the ecosystems. The information can then be used to inform modern conservation efforts.

"We're trying to find the earliest human records as well as what was there before humans arrived," Dr Louys said.

"Once we know what was there before humans got there, we see what type of impact they had."

Dr Louys returned from the project's latest expedition to East Timor in August and has presented the findings at the Meetings of the Society of Vertebrate Palaeontology in Texas.

Source : Australian National University

A new dimension to high-temperature superconductivity discovered

A team led by scientists at the Department of Energy's SLAC National Accelerator Laboratory combined powerful magnetic pulses with some of the brightest X-rays on the planet to discover a surprising 3-D arrangement of a material's electrons that appears closely linked to a mysterious phenomenon known as high-temperature superconductivity.

This unexpected twist marks an important milestone in the 30-year journey to better understand how materials known as high-temperature superconductors conduct electricity with no resistance at temperatures hundreds of degrees Fahrenheit above those of conventional metal superconductors but still hundreds of degrees below freezing. The study was published today in Science.
The study also resolves an apparent mismatch in data from previous experiments and charts a new course for fully mapping the behaviors of electrons in these exotic materials under different conditions. Researchers have an ultimate goal to aid the design and development of new superconductors that work at warmer temperatures.

'Totally Unexpected' Physics

"This was totally unexpected, and also very exciting. This experiment has identified a new ingredient to consider in this field of study. Nobody had seen this 3-D picture before," said Jun-Sik Lee, a SLAC staff scientist and one of the leaders of the experiment conducted at SLAC's Linac Coherent Light Source (LCLS) X-ray laser. "This is an important step in understanding the physics of high-temperature superconductors."
The dream is to push the operating temperature for superconductors to room temperature, he added, which could lead to advances in computing, electronics and power grid technologies.
There are already many uses for standard superconducting technology, from MRI machines that diagnose brain tumors to a prototype levitating train, the CERN particle collider that enabled the Nobel Prize-winning discovery of the Higgs boson and ultrasensitive detectors used to hunt for dark matter, the invisible constituent believed to make up most of the mass of the universe. A planned upgrade to the LCLS, known as LCLS-II, will include a superconducting particle accelerator.

The New Wave in Superconductivity

 he 3-D effect that scientists observed in the LCLS experiment, which occurs in a superconducting material known as YBCO (yttrium barium copper oxide), is a newly discovered type of 'charge density wave.' This wave does not have the oscillating motion of a light wave or a sound wave; it describes a static, ordered arrangement of clumps of electrons in a superconducting material. Its coexistence with superconductivity is perplexing to researchers because it seems to conflict with the freely moving electron pairs that define superconductivity.

The 2-D version of this wave was first seen in 2012 and has been studied extensively. The LCLS experiment revealed a separate 3-D version that appears stronger than the 2-D form and closely tied to both the 2-D behavior and the material's superconductivity.

The experiment was several years in the making and required international expertise to prepare the specialized samples and construct a powerful customized magnet that produced magnetic pulses compressed to thousandths of a second. Each pulse was 10-20 times stronger than those from the magnets in a typical medical MRI machine.

A Powerful Blend of Magnetism and Light

Those short but intense magnetic pulses suppressed the superconductivity of the YBCO samples and provided a clearer view of the charge density wave effects. They were immediately followed at precisely timed intervals by ultrabright LCLS X-ray laser pulses, which allowed scientists to measure the wave effects.
"This experiment is a completely new way of using LCLS that opens up the door for a whole new class of future experiments," said Mike Dunne, LCLS director.

Researchers conducted many preparatory experiments at SLAC's Stanford Synchrotron Radiation Lightsource (SSRL), which also produces X-rays for research. LCLS and SSRL are DOE Office of Science User Facilities. Scientists from SIMES, the Stanford Institute for Materials and Energy Sciences at SLAC, and SSRL and LCLS were a part of the study.

 Researchers discover a new dimension to high-temperature superconductivity
A view of the X-ray Correlation Spectroscopy experimental station at SLAC's Linac Coherent Light Source (LCLS) X-ray laser.

"I've been excited about this experiment for a long time," said Steven Kivelson, a Stanford University physics professor who contributed to the study and has researched high-temperature superconductors since 1987. Kivelson said the experiment sets very clear boundaries on the temperature and strength of the magnetic field at which the newly observed 3-D effect emerges. "There is nothing vague about this," he said. "You can now make a definitive statement: In this material a new phase exists." The experiment also adds weight to the growing evidence that charge density waves and superconductivity "can be thought of as two sides of the same coin," he added.

In Search of Common Links

But it is also clear that YBCO is incredibly complex, and a more complete map of all of its properties is required to reach any conclusions about what matters most to its superconductivity, said Simon Gerber of SIMES and Hoyoung Jang of SSRL, the lead authors of the study.

Follow-up experiments are needed to provide a detailed visualization of the 3-D effect, and to learn whether the effect is universal across all types of high-temperature superconductors, said SLAC staff scientist and SIMES investigator Wei-Sheng Lee, who co-led the study with Jun-Sik Lee of SSRL and Diling Zhu of LCLS. "The properties of this material are much richer than we thought," Lee said.
"We continue to make new and surprising observations as we develop new experimental tools," Zhu added.

China state-owned firm to build $15 bn chip plant

A state-owned Chinese company said Friday it plans to pour nearly $15 billion into a giant memory chip factory, as Beijing seeks to create homegrown semiconductor champions to reduce reliance on foreign technology.

Tongfang Guoxin Electronics Co. aims to invest 93.8 billion yuan ($14.8 billion) in the plant, it said in a filing with the Shenzhen stock exchange.

Tongfang Guoxin is controlled by Tsinghua Holdings Co., the commercial arm of Tsinghua University in Beijing, and ultimately China's education ministry.

China is regularly accused of cyberspying by the West but says it is a victim of hacking, and it has been encouraging research and development of homegrown semiconductor technologies as part of its "national information security strategy".

China needed to overcome "long-time restrictions imposed by the United States, Japan and Europe" over semiconductor materials and equipment, the ministry of industry and information technology said in a statement in June.

In the stock exchange filing, Tongfang Guoxin said: "China will only be able to effectively guarantee its information security by making its own... integrated circuits."

The company will raise up to 80 billion yuan by selling new shares to eight companies and employees, it said, in what could be one of the world's biggest private placement deals.

Six of the eight corporate buyers in the placement are themselves affiliates of Tsinghua Holdings, according to the statement.

Most of the proceeds will go towards the new plant—which will take two years to go into trial operations—while 25 percent will be used to acquire firms in the semiconductor industry, it added.

Martian desiccation

Mars has been all over the news, from the blockbuster finding of seasonal water on the Red Planet to the wildly successful film, The Martian. Now, researchers--including those at the University of Iowa--have learned more about what happened to the climate on Mars since it was a warm and watery planet billions of years ago.

The researchers announced on Thursday that NASA's MAVEN (Mars Atmosphere and Volatile Evolution) mission has determined the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind. Loss of gas to space appears to have been an important part of why the Martian climate went from an early, warm, wet one that might have been able to support life at the surface to the cold, dry, desert planet we see today.

Jasper Halekas, associate professor in physics and astronomy at the UI and principal investigator of the Solar Wind Ion Analyzer instrument on MAVEN, took part in a NASA media briefing in which the agency gave its first results from the mission.

Halekas explains the sun has played a role in the planet's loss of atmosphere and water to space, by the solar wind accelerating ions (electrically charged gas atoms) in the Martian upper atmosphere and stripping them from the planet altogether. He says that powerful solar storms, called coronal mass ejections, can multiply the ions' escape by as much as a factor of 20.

Halekas adds that the coronal mass ejections produce such a pronounced effect because the solar storms collapsed the Martian magnetosphere, reducing its size by approximately 600 miles, and exposing more of the planet's atmosphere to the solar wind.

"The removal of atmosphere from Mars by episodic extreme events may have been very important over Mars' history, just as a single tsunami can remove a portion of the ocean shore that would have taken millennia to erode by the steady lapping of the tides," Halekas says.

The first scientific results from the MAVEN mission were published online on Thursday in a series of papers in the journals Science and Geophysical Research Letters. Halekas and Suranga Ruhunusiri, a post-doctoral researcher in physics and astronomy at the UI, are co-authors on 21 of the papers and are lead authors on three manuscripts.

MAVEN measurements have demonstrated that the solar wind is able to strip away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second. The loss comes from three different regions around the planet: above the Martian poles in a "polar plume"; down the "tail," where the solar wind flows behind Mars; and from the extended cloud of gas that always surrounds Mars.

A series of dramatic solar storms hit Mars' atmosphere in March 2015, and MAVEN found that the loss was accelerated. The combination of greater loss rates and increased solar storms in the past suggests that loss of atmosphere to space was likely a major process in changing the Martian climate.

"Like the theft of a few coins from a cash register every day, the loss becomes significant over time," says MAVEN Principal Investigator Bruce Jakosky, of the University of Colorado. "More importantly, with MAVEN we've seen that the atmospheric erosion increases significantly during solar storms. So we think that the loss rate was much higher billions of years ago when the sun was young and more active. As a result, we expect that loss of atmosphere to space was likely to have been a major process in changing the Martian climate."

The mission's goal is to determine how much of the planet's atmosphere and water has been lost to space. Scientists are interested in the history of liquid water on Mars because it has had a major geological impact on the surface over time and because it is necessary for life as we know it to exist at the surface.

MAVEN has been operating at Mars for just over a year and is about to complete its primary science mission on November 16, 2015.

Adults' happiness on the decline

Are you less happy than your parents were at the same age? It may not be all in your head. Researchers led by San Diego State University professor Jean M. Twenge found adults over age 30 are not as happy as they used to be, but teens and young adults are happier than ever.

Researchers -- including Ryne A. Sherman of Florida Atlantic University and Sonja Lyubomirsky of University of California, Riverside -- analyzed data from four nationally representative samples of 1.3 million Americans ages 13 to 96 taken from 1972 to 2014.

They found that after 2010, the age advantage for happiness found in prior research vanished. There is no longer a positive correlation between age and happiness among adults, and adults older than 30 are no longer significantly happier than those ages 18 to 29.

"Our current culture of pervasive technology, attention-seeking, and fleeting relationships is exciting and stimulating for teens and young adults, but may not provide the stability and sense of community that mature adults require," said Twenge, who is also the author of "Generation Me."

Data showed that 38 percent of adults older than 30 said they were "very happy" in the early 1970s, which shrunk to 32 percent in the 2010s. Twenty-eight percent of adults ages 18 to 29 said they were "very happy" in the early 1970s, versus 30 percent in the 2010s.

Over the same time, teens' happiness increased: 19 percent of 12th graders said they were "very happy" in the late 1970s, versus 23 percent in the 2010s.

"American culture has increasingly emphasized high expectations and following your dreams-- things that feel good when you're young," Twenge said. "However, the average mature adult has realized that their dreams might not be fulfilled, and less happiness is the inevitable result. Mature adults in previous eras might not have expected so much, but expectations are now so high they can't be met."

That drop in happiness occurred for both men and women, said Twenge. "A previous study in 2008 got quite a bit of attention when it found that women's happiness had declined relative to men's. We now find declines in both men's and women's happiness, especially after 2010."

The results were published in Social Psychological and Personality Science