Culture

Although socio-economic status is known to influence health, strong evidence of the association between economic vulnerability in childhood and the health of older adults was still missing. As part of the "National centre of Competence in Research - NCCR LIVES" funded by the Swiss National Science Foundation, researchers at the University of Geneva (UNIGE) examined data from more than 24,000 people aged 50 to 96 living in 14 European countries. Socio-economically disadvantaged individuals in childhood were found to be at greater risk of low muscle strength at an older age - a good indicator of their overall health status. Moreover, this risk is not offset by an improvement in their socio-economic status as adults, which proves that the first years of life are indeed critical. This would mean that inequalities in childhood are biologically embodied to literally "get into the skin". Why? The scientists suggest that a physiological deregulation caused by chronic stress in childhood might change the body's ability to maintain good health along time. These findings can be read in Age and Ageing.

How do social inequalities express themselves in terms of objectively measurable health outcomes, over a very long time? Boris Cheval and Stéphane Cullati, researchers at the NCCR LIVES and at the UNIGE Faculty of Medicine, sought to answer this question. To do so, they analysed nearly 100,000 data from the Survey of Health, Ageing and Retirement in Europe, a 12-year population survey conducted by the European Union to study the economic, social and health status of older people.

Thus, 24,179 participants, half of them men and half women, were included in the analysis. Participants' gripping strength was assessed with portable dynamometer - data that well predicts the overall health status - and compared to a measure of four socio-economic indicators of participants at age 10. The indicators were: the occupation of the primary breadwinner, the number of books at home - a surprisingly reliable indicator of children's future health - the quality of housing and the number of people living in it compared to the number of rooms. "The results showed that people who faced poor socio-economic circumstances in childhood had on average less muscular strength than those who were better off in their early years," explains Boris Cheval. "Even when adjusted to take into account socioeconomic factors and health behaviours (physical activity, tobacco, alcohol, nutrition) in adulthood, associations remained very significant, especially among women, who were often less susceptible to benefit from social mobility."

From social life to biology: stress seems at stake

Social epidemiology studies often point to the indirect effects of social determinants of health: behaviours, for example, are not the same according to socio-economic status. "Beyond that, our study suggests a direct, biological and lasting effect of a poor start in life,» says Boris Cheval. "To explain our findings, we hypothesize a physiological deregulation induced by chronic stress due to the difficult circumstances of childhood." Many studies indeed show that the physiological response to stress develops in childhood. Early and lasting stress can therefore alter the system's response to stress, affecting in particular the functioning of the immune and inflammatory systems, and the general health status. Similarly, the level of household income in adulthood - a major stress factor in the event of financial problems - strongly correlates with objective muscle strength. "A growing body of scientific evidence indicates that the social is incarnated in the body, and thus shows the urgency, when it comes to health, to consider individuals under all of their life circumstances," adds Stéphane Cullati. "In addition, our results show a notable difference between countries: Scandinavians are generally in better health, regardless of their socio-economic level. They also live in the most egalitarian countries in terms of access to health care and education." Researchers will continue their analysis to determine how socio-economic systems mitigates the correlation between underprivileged childhood and poor health in old age and influences health trajectories.

Researchers have unlocked the genetic code behind some of the brightest and most vibrant colours in nature. The paper, published in the journal PNAS, is the first study of the genetics of structural colour - as seen in butterfly wings and peacock feathers - and paves the way for genetic research in a variety of structurally coloured organisms.

The study is a collaboration between the University of Cambridge and Dutch company Hoekmine BV and shows how genetics can change the colour, and appearance, of certain types of brightly-coloured bacteria. The results open up the possibility of harvesting these bacteria for the large-scale manufacturing of nanostructured materials: biodegradable, non-toxic paints could be 'grown' and not made, for example.

Flavobacterium is a type of bacteria that packs together in colonies that produce striking metallic colours, which come not from pigments, but from their internal structure, which reflects light at certain wavelengths. Scientists are still puzzled as to how these intricate structures are genetically engineered by nature, however.

"It is crucial to map the genes responsible for the structural colouration for further understanding of how nanostructures are engineered in nature," said first author Villads Egede Johansen, from Cambridge's Department of Chemistry. "This is the first systematic study of the genes underpinning structural colours -- not only in bacteria, but in any living system."

The researchers compared the genetic information to optical properties and anatomy of wild-type and mutated bacterial colonies to understand how genes regulate the colour of the colony.

By genetically mutating the bacteria, the researchers changed their dimensions or their ability to move, which altered the geometry of the colonies. By changing the geometry, they changed the colour: they changed the original metallic green colour of the colony in the entire visible range from blue to red. They were also able to create duller colouration or make the colour disappear entirely.

"We mapped several genes with previously unknown functions and we correlated them to the colonies' self-organisational capacity and their colouration," said senior author Dr Colin Ingham, CEO of Hoekmine BV.

"From an applied perspective, this bacterial system allows us to achieve tuneable living photonic structures that can be reproduced in abundance, avoiding traditional nanofabrication methods," said co-senior author Dr Silvia Vignolini from the Cambridge's Department of Chemistry. "We see a potential in the use of such bacterial colonies as photonic pigments that can be readily optimised for changing colouration under external stimuli and that can interface with other living tissues, thereby adapting to variable environments. The future is open for biodegradable paints on our cars and walls -- simply by growing exactly the colour and appearance we want!"

Thousands of appointments cancelled; effects greatest when emergency care withdrawn

The 2016 junior doctors strikes in England had a 'significant' impact on the provision of healthcare, with thousands of appointments cancelled, and significantly fewer admissions and A&E attendances than expected, reveals research published in the online journal BMJ Open.

The effects were greatest during the last of the periods of industrial action, when junior doctors withdrew emergency care. But there was no obvious change in the death rate during any of the strikes.

In the first four months of 2016, junior doctors from all specialties across England went on strike in protest against contractual changes brought in by the government. Before these strikes there had been only one other strike in the previous 40 years--in 2012.

Each of the four strikes lasted 24-48 hours: 12 January; 10 February; 9-10 March; and 26-27 April. This last was the only strike that included withdrawal of emergency care.

Gaps in routine care offer an opportunity to assess the effectiveness of current systems and pinpoint weaknesses in response to staff shortages.

The researchers therefore compared hospital activity the week of each of the strikes with that from the preceding and following weeks. They focused on numbers of admissions, outpatient appointments, and A&E attendances.

During the 12 weeks of the study, there were 3.4 million admissions, 27 million outpatient appointments, and 3.4 million A&E attendances.

Compared with the weeks preceding and following the strikes, there were over 9 percent (31,651) fewer admissions, nearly 7 percent (23,895) fewer A&E attendances, and 6 percent (173,462) fewer outpatient appointments than expected.

April's strike had the largest impact on services: there were over 15 percent (18,194) fewer admissions, including nearly 8 per cent (3383) fewer emergency admissions, and almost 20 percent fewer planned admissions.

Hospitals scheduled 11 percent (109,915) fewer outpatient appointments during this strike, while patients kept 134,711 (just over 17%) fewer of them. The number of outpatient appointments cancelled by hospitals also rose by almost 67 percent (43,823).

During all four strikes, hospitals cancelled nearly 300,000 outpatient appointments--52 percent higher than the volume expected for this period--possibly to protect more critical services, suggest the researchers.

Certain regions seemed to be disproportionately affected. The proportion of cancelled appointments increased to between 66 and 68 percent in Yorkshire and the Humber, South East Coast, and London. These regions also had the largest proportions of missed appointments.

The impact on emergency admissions was smaller, but greatest in the South West and the West Midlands.

The number of recorded deaths didn't change significantly during the strikes and wasn't higher than expected, due to relatively small numbers. But hospital mortality is likely to be the least sensitive outcome for quality and safety concerns in this context, the researchers point out.

This is because deaths caused by poor care aren't likely to show up immediately, nor is it clear whether patient health might have worsened as a result of delayed appointments and procedures, they explain.

But these issues, along with the financial impact, might be fertile avenues to explore in future research, they suggest.

They accept that they didn't assess the impact of the strikes on patients who didn't attend A&E, or the potential impact on the so-called 'weekend effect,' or how patients felt about their delayed care.

But they nevertheless conclude: "Industrial action by junior doctors during early 2016 caused a significant impact on the provision of healthcare provided by English hospitals."

A new online game puts players in the shoes of an aspiring propagandist to give the public a taste of the techniques and motivations behind the spread of disinformation - potentially "inoculating" them against the influence of so-called fake news in the process.

Researchers at the University of Cambridge have already shown that briefly exposing people to tactics used by fake news producers can act as a "psychological vaccine" against bogus anti-science campaigns.

While the previous study focused on disinformation about climate science, the new online game is an experiment in providing "general immunity" against the wide range of fake news that has infected public debate.

The game encourages players to stoke anger, mistrust and fear in the public by manipulating digital news and social media within the simulation.

Players build audiences for their fake news sites by publishing polarizing falsehoods, deploying twitter bots, photo-shopping evidence, and inciting conspiracy theories in the wake of public tragedy - all while maintaining a "credibility score" to remain as persuasive as possible.

A pilot study conducted with teenagers in a Dutch high school used an early paper-and-pen trial of the game, and showed the perceived "reliability" of fake news to be diminished in those that played compared to a control group.

The research and education project, a collaboration between Cambridge researchers and Dutch media collective DROG, is launching an English version of the game online today at http://www.fakenewsgame.org.

The psychological theory behind the research is called "inoculation":

"A biological vaccine administers a small dose of the disease to build immunity. Similarly, inoculation theory suggests that exposure to a weak or demystified version of an argument makes it easier to refute when confronted with more persuasive claims," says Dr Sander van der Linden, Director of Cambridge University's Social Decision-Making Lab.

"If you know what it is like to walk in the shoes of someone who is actively trying to deceive you, it should increase your ability to spot and resist the techniques of deceit. We want to help grow 'mental antibodies' that can provide some immunity against the rapid spread of misinformation."

Based in part on existing studies of online disinformation, and taking cues from actual conspiracy theories about organisations such as the United Nations, the game is set to be translated for countries such as Ukraine, where disinformation casts a heavy shadow.

There are also plans to adapt the framework of the game for anti-radicalisation purposes, as many of the same manipulation techniques - using false information to provoke intense emotions, for example - are commonly deployed by recruiters for religious extremist groups.

"You don't have to be a master spin doctor to create effective disinformation. Anyone can start a site and artificially amplify it through twitter bots, for example. But recognising and resisting fake news doesn't require a PhD in media studies either," says Jon Roozenbeek, a researcher from Cambridge's Department of Slavonic Studies and one of the game's designers.

"We aren't trying to drastically change behavior, but instead trigger a simple thought process to help foster critical and informed news consumption."

Roozenbeek points out that some efforts to combat fake news are seen as ideologically charged. "The framework of our game allows players to lean towards the left or right of the political spectrum. It's the experience of misleading through news that counts," he says.

The pilot study in the Netherlands using a paper version of the game involved 95 students with an average age of 16, randomly divided into treatment and control.

This version of the game focused on the refugee crisis, and all participants were randomly presented with fabricated news articles on the topic at the end of the experiment.

The treatment group were assigned roles - alarmist, denier, conspiracy theorist or clickbait monger - and tasked with distorting a government fact sheet on asylum seekers using a set of cards outlining common propaganda tactics consistent with their role.

They found fake news to be significantly less reliable than the control group, who had not produced their own fake article. Researchers describe the results of this small study as limited but promising. The study has been accepted for publication in the Journal of Risk Research.

The team are aiming to take their "fake news vaccine" trials to the next level with today's launch of the online game.

With content written mostly by the Cambridge researchers along with Ruurd Oosterwoud, founder of DROG, the game only takes a few minutes to complete. The hope is that players will then share it to help create a large anonymous dataset of journeys through the game.

The researchers can then use this data to refine techniques for increasing media literacy and fake news resilience in a 'post-truth' world. "We try to let players experience what it is like to create a filter bubble so they are more likely to realize they may be living in one," adds van der Linden.

For the first four billion years of Earth's history, our planet's continents would have been devoid of all life except microbes.

All of this changed with the origin of land plants from their pond scum relatives, greening the continents and creating habitats that animals would later invade.

The timing of this episode has previously relied on the oldest fossil plants which are about 420 million years old.

New research, published today in the journal Proceedings of the National Academy of Sciences USA, indicates that these events actually occurred a hundred million years earlier, changing perceptions of the evolution of the Earth's biosphere.

Plants are major contributors to the chemical weathering of continental rocks, a key process in the carbon cycle that regulates Earth's atmosphere and climate over millions of years.

The team used 'molecular clock' methodology, which combined evidence on the genetic differences between living species and fossil constraints on the age of their shared ancestors, to establish an evolutionary timescale that sees through the gaps in the fossil record.

Dr Jennifer Morris, from the University of Bristol's School of Earth Sciences and co-lead author on the study, explained: "The global spread of plants and their adaptations to life on land, led to an increase in continental weathering rates that ultimately resulted in a dramatic decrease the levels of the 'greenhouse gas' carbon dioxide in the atmosphere and global cooling.

"Previous attempts to model these changes in the atmosphere have accepted the plant fossil record at face value - our research shows that these fossil ages underestimate the origins of land plants, and so these models need to be revised."

Co-lead author Mark Puttick described the team's approach to produce the timescale. He said: "The fossil record is too sparse and incomplete to be a reliable guide to date the origin of land plants. Instead of relying on the fossil record alone, we used a 'molecular clock' approach to compare differences in the make-up of genes of living species - these relative genetic differences were then converted into ages by using the fossil ages as a loose framework.

"Our results show the ancestor of land plants was alive in the middle Cambrian Period, which was similar to the age for the first known terrestrial animals."

One difficulty in the study is that the relationships between the earliest land plants are not known. Therefore the team, which also includes members from Cardiff University and the Natural History Museum, London, explored if different relationships changed the estimated origin time for land plants.

Leaders of the overall study, Professor Philip Donoghue and Harald Schneider added: "We used different assumptions on the relationships between land plants and found this did not impact the age of the earliest land plants.

"Any future attempts to model atmospheric changes in deep-time must incorporate the full range of uncertainties we have used here."

DALLAS, Feb. 19, 2018 -- Mental stress was more likely to cause chest pain in young women who have had a heart attack compared to a comparable group of men, according to a study published in a special issue of Circulation, a journal of the American Heart Association that also includes an additional 10 original studies and research letters about the unique role gender plays in heart health.

This is the second Go Red For Women issue of Circulation, celebrating the Association's focus on women during the month of February. It includes studies about heart disease linked to pregnancy, spontaneous preterm delivery, pre-eclampsia, mental stress, risk factors, stroke and other topics.

"In the United States, 1 in 4 women die from heart disease, yet the vast majority of women remain unaware that the single greatest risk to their health and longevity is heart disease," said Joseph Hill, M.D., Ph.D., editor-in-chief of Circulation and professor of medicine and molecular biology at U.T. Southwestern in Dallas, Texas. "With this issue we shine a bright light on some of the best science emerging in the domain of women's cardiovascular health," he said.

Editorial by Sharon C. Reimold, M.D. and Joseph A. Hill, M.D., Ph.D.

Joseph A. Hill, M.D., Ph.D., editor-in-chief of Circulation; professor of medicine and molecular biology and chief of cardiology at UT Southwestern Medical Center, Dallas, Texas
After Feb. 19, view editorial online

Highlighted studies include:

Mental stress Induced-myocardial ischemia in young patients with recent myocardial infarction: sex differences and mechanisms

Myocardial ischemia is defined as inadequate blood flow to the heart muscle due to reduction in blood flow to the heart, which can be caused by blockages (plaque) in the major coronary arteries or by microvascular dysfunction, which means dysfunction of the small arteries leading to the heart.

This study included 306 patients (150 women and 156 men) under 61 years of age who were hospitalized for heart attacks in the previous 8 months and 112 community controls (58 women and 54 men) matched for sex and age to the heart attack patients.

The researchers measured how well the participants' blood vessels functioned at rest and 30 minutes after mental stress caused by a public speaking task. They found that young female heart attack survivors had twice the risk of experiencing myocardial ischemia induced by mental stress.

Viola Vaccarino, M.D., Ph.D., professor of medicine, Rollins School of Public Health, Emory University, Atlanta, Georgia
After Feb. 19, view the manuscript online

Sex differences in the presentation and perception of symptoms among young patients with myocardial infarction: evidence from the VIRGO study

Some studies report that women are less likely to have chest pain during a heart attack. For this study, researchers interviewed 2,009 women and 976 men aged 18-55 hospitalized for heart attacks regarding symptoms they experienced during their heart attack.

Approximately 90 percent of both women and men experienced chest pain (defined as pain, pressure, tightness or discomfort) during their heart attack. However, women were more likely to report additional symptoms compared to men, such as nausea, palpitations and pain or discomfort in the jaw, neck, arms or between the shoulder blades.

Approximately 29.5 percent of women and 22.1 percent of men sought medical care for similar symptoms before their hospitalization, but 53 percent of the women reported that their healthcare provider did not think these symptoms were heart related as compared with 37 percent of men.

Judith Lichtman, M.D., associate professor, Yale School of Public Health, New Haven, Connecticut
After Feb. 19, view the manuscript online

Additional original articles and research letters that appear in the second Go Red For Women issue of Circulation are available to the public and include:

Female sex is a risk modifier rather than a risk factor for stroke in atrial fibrillation: Should we use a CHA2DS2-VA score rather than CHA2DS2-VASc?

Peter Brønnum Nielsen, Ph.D., professor, Aalborg University Hospital, Skovvej, Denmark
After Feb. 19, view the manuscript online

Metabolic predictors of incident coronary heart disease in women

Nina P. Paynter, Ph.D, assistant professor of medicine, Harvard Medical School, Boston, Massachusetts
After Feb. 19, view the manuscript online

Sex difference in patients with ischemic heart failure undergoing surgical revascularization: results from the STICH trial

lleana L. Piña, M.D.; M.P.H., professor of medicine, epidemiology and population health, Albert Einstein College of Medicine, New York, New York
After Feb. 19, view the manuscript online

Pregnancy outcome in women with rheumatic mitral valve disease: Results from the registry of pregnancy and cardiac disease (ROPAC)

J.W. Roos-Hesselink, M.D, Ph.D., professor of adult congenital cardiology, The Erasmus University Medical Center, Rotterdam, The Netherlands
After Feb. 19, view the manuscript online

Myocardial scar is prevalent and associated with subclinical myocardial dysfunction in women with suspected ischemia but no obstructive coronary artery disease: From the women's ischemia syndrome evaluation - coronary vascular dysfunction study

Janet Wei, M.D., assistant professor of medicine and biomedical sciences, Cedars-Sinai Heart Institute, Los Angeles, California
After Feb. 19, view the manuscript online

Genetics, lifestyle, and LDL cholesterol in young and apparently healthy women

Jan Albert Kuivenhoven, associate professor, University Medical Center, Groningen, University of Groningen, The Netherlands
After Feb. 19, view the manuscript online

Prevalence of subclinical coronary artery disease assessed by coronary computed tomography angiography among women with a history of preeclampsia aged 45 to 55 years

Gerbrand A. Zoet, M.D., Ph.D., University Medical Center Utrecht, The Netherlands
After Feb. 19, view the manuscript online

Long-term analysis of sex differences in prestigious authorships in cardiovascular research supported by the NIH

Carolin Lerchenmüller, M.D.; Harvard University School of Medicine, Boston, Massachusetts
After Feb. 19, view the manuscript online

A thousand-year-old tooth has provided genetic evidence that the so-called "Taíno", the first indigenous Americans to feel the full impact of European colonisation after Columbus arrived in the New World, still have living descendants in the Caribbean today.

Researchers were able to use the tooth of a woman found in a cave on the island of Eleuthera in the Bahamas to sequence the first complete ancient human genome from the Caribbean. The woman lived at some point between the 8th and 10th centuries, at least 500 years before Columbus made landfall in the Bahamas.

The results provide unprecedented insights into the genetic makeup of the Taíno - a label commonly used to describe the indigenous people of that region. This includes the first clear evidence that there has been some degree of continuity between the indigenous peoples of the Caribbean and contemporary communities living in the region today.

Such a link had previously been suggested by other studies based on modern DNA. None of these, however, was able to draw on an ancient genome. The new research finally provides concrete proof that indigenous ancestry in the region has survived to the present day.

Comparing the ancient Bahamian genome to those of contemporary Puerto Ricans, the researchers found that they were more closely related to the ancient Taíno than any other indigenous group in the Americas. However, they argue that this characteristic is unlikely to be exclusive to Puerto Ricans alone and are convinced that future studies will reveal similar genetic legacies in other Caribbean communities.

The findings are likely to be especially significant for people in the Caribbean and elsewhere who have long claimed indigenous Taíno heritage, despite some historical narratives that inaccurately brand them "extinct". Such misrepresentations have been heavily criticised by historians and archaeologists, as well as by descendant communities themselves, but until now they lacked clear genetic evidence to support their case.

The study was carried out by an international team of researchers led by Dr Hannes Schroeder and Professor Eske Willerslev within the framework of the ERC Synergy project NEXUS1492. The findings are published in the journal Proceedings of the National Academy of Sciences (PNAS).

Lead author Schroeder, from the University of Copenhagen who carried out the research as part of the NEXUS1492 project, said: "It's a fascinating finding. Many history books will tell you that the indigenous population of the Caribbean was all but wiped out, but people who self-identify as Taíno have always argued for continuity. Now we know they were right all along: there has been some form of genetic continuity in the Caribbean."

Willerslev, who has dual posts at St John's College, University of Cambridge, and the University of Copenhagen, said: "It has always been clear that people in the Caribbean have Native American ancestry, but because the region has such a complex history of migration, it was difficult to prove whether this was specifically indigenous to the Caribbean, until now."

The researchers were also able to trace the genetic origins of the indigenous Caribbean islanders, showing that they were most closely related to Arawakan-speaking groups who live in parts of northern South America today. This suggests that the origins of at least some the people who migrated to the Caribbean can be traced back to the Amazon and Orinoco Basins, where the Arawakan languages developed.

The Caribbean was one of the last parts of the Americas to be populated by humans starting around 8,000 years ago. By the time of European colonization, the islands were a complex patchwork of different societies and cultures. The "Taíno" culture was dominant in the Greater, and parts of the Lesser Antilles, as well as the Bahamas, where the people were known as Lucayans.

To trace the genetic origins of the Lucayans the researchers compared the ancient Bahamian genome with previously published genome-wide datasets for over 40 present-day indigenous groups from the Americas. In addition, they looked for traces of indigenous Caribbean ancestry in present-day populations by comparing the ancient genome with those of 104 contemporary Puerto Ricans included in the 1000 Genomes Project. The 10-15% of Native American ancestry in this group was shown to be closely related to the ancient Bahamian genome.

Jorge Estevez, a Taíno descendant who works at the National Museum of the American Indian in New York and assisted the project team, said that as a boy growing up in the United States, he was told stories about his Taíno ancestors at home, but at school was taught that the same ancestors had died out. "I wish my grandmother were alive today so that I could confirm to her what she already knew," he added. "It shows that the true story is one of assimilation, certainly, but not total extinction. I am genuinely grateful to the researchers. Although this may have been a matter of scientific inquiry for them, to us, the descendants, it is truly liberating and uplifting."

Although indigenous Caribbean communities were island-based, the researchers found very little genomic evidence of isolation or inbreeding in the ancient genome. This reinforces earlier genetic research led by Willerslev, which suggests that early human communities developed surprisingly extensive social networks, long before the term had digital connotations. It also echoes ongoing work by researchers at the Faculty of Archaeology in Leiden and others indicating the connectedness of indigenous Caribbean communities.

Professor Corinne Hofman from Leiden University and PI of the NEXUS1492 project, said: "Archaeological evidence has always suggested that large numbers of people who settled the Caribbean originated in South America, and that they maintained social networks that extended far beyond the local scale. Historically, it has been difficult to back this up with ancient DNA because of poor preservation, but this study demonstrates that it is possible to obtain ancient genomes from the Caribbean and that opens up fascinating new possibilities for research."

New research shows that the loss of biodiversity can increase the risk of "extinction cascades", where an initial species loss leads to a domino effect of further extinctions.

The researchers, from the University of Exeter, showed there is a higher risk of extinction cascades when other species are not present to fill the "gap" created by the loss of a species.

Even if the loss of one species does not directly cause knock-on extinctions, the study shows that this leads to simpler ecological communities that are at greater risk of "run-away extinction cascades" with the potential loss of many species.

With extinction rates at their highest levels ever and numerous species under threat due to human activity, the findings are a further warning about the consequences of eroding biodiversity.

"Interactions between species are important for ecosystem (a community of interacting species) stability," said Dr Dirk Sanders, of the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall. "And because species are interconnected through multiple interactions, an impact on one species can affect others as well.

"It has been predicted that more complex food webs will be less vulnerable to extinction cascades because there is a greater chance that other species can step in and buffer against the effects of species loss.

"In our experiment, we used communities of plants and insects to test this prediction."

The researchers removed one species of wasp and found that it led to secondary extinctions of other, indirectly linked, species at the same level of the food web.

This effect was much stronger in simple communities than for the same species within a more complex food web.

Dr Sanders added: "Our results demonstrate that biodiversity loss can increase the vulnerability of ecosystems to secondary extinctions which, when they occur, can then lead to further simplification causing run-away extinction cascades."

The study, supported by France's Sorbonne Université, is published in the journal Proceedings of the National Academy of Sciences.

The paper is entitled: "Trophic redundancy reduces vulnerability to extinction cascades."

How extinction cascades work

The loss of a predator can initiate a cascade, such as in the case of wolves, where their extinction on one mountain can cause a large rise in the number of deer. This larger number of deer then eats more plant material than they would have before. This reduction in vegetation can cause extinctions in any species that also relies on the plants, but are potentially less competitive, such as rabbits or insects.

ANN ARBOR, Mich. -- Without a doctor or dentist's guidance, some parents don't follow national recommendations for early dental care for their children, a new national poll finds.

One in 6 parents who did not receive advice from a health care provider believed children should delay dentist visits until age 4 or older - years later than what experts recommend - according to this month's C.S. Mott Children's Hospital National Poll on Children's Health.

The American Academy of Pediatrics and the American Dental Association both recommend starting dental visits around age one when baby teeth emerge.

"Visiting the dentist at an early age is an essential part of children's health care," says Mott poll co-director Sarah Clark. "These visits are important for the detection and treatment of early childhood tooth decay and also a valuable opportunity to educate parents on key aspects of oral health."

"Our poll finds that when parents get clear guidance from their child's doctor or dentist, they understand the first dental visit should take place at an early age. Without such guidance, some parents turn to family or friends for advice. As recommendations change, they may be hearing outdated information and not getting their kids to the dentist early enough."

The nationally representative poll is based on responses from 790 parents with at least one child aged 0-5

More than half of parents did not receive guidance from their child's doctor or a dentist about when to start dentist visits. Among parents who were not prompted by a doctor or dentist, only 35 percent believed dentist visits should start when children are a year or younger as is recommended.

Over half of parents (60 percent) reported their child has had a dental visit with most parents (79 percent) believing the dentist visit was worthwhile.

Among the 40 percent of parents whose child has not had a dental visit, common reasons for not going were that the child is not old enough (42 percent), the child's teeth are healthy (25 percent), and the child would be scared of the dentist (15 percent).

Experts say starting dental visits early helps set children up for healthy oral hygiene, with parents learning about correct brushing techniques, the importance of limiting sugary drinks, and the need to avoid putting children to bed with a bottle.

Early childhood caries (dental decay in baby teeth) may also be detected at young ages, allowing for treatment of decay to avoid more serious problems. In young children with healthy teeth, dentists may apply fluoride varnish to prevent future decay.

A quarter of parents who had delayed dental visits said their child's teeth are healthy but Clark notes it is unlikely that a parent could detect early tooth decay.

"Parents may not notice decay until there's discoloration, and by then the problem has likely become significant," she says. "Immediate dental treatment at the first sign of decay can prevent more significant dental problems down the road, which is why having regular dentist visits throughout early childhood is so important."

Another factor that may delay dental care is that healthcare recommendations for early childhood are often focused on well-child visits with medical providers, Clark notes.

"Parents hear clear guidelines on when they should begin well-child visits for their child's health and often schedule the first visit before they even bring their baby home from the hospital. Doctors typically prompt parents to stick to a standard schedule for immunizations and other preventive care," she says.

"Parents get much less guidance, however, on when to start taking their child to the dentist, with less than half saying they have received professional advice. This lack of guidance may mean many parents delay the start of dental visits past the recommended age."

Parents with higher income and education, and those with private dental insurance, were more likely to report that a doctor or dentist provided guidance on when to start dental visits.

"Our poll suggests that families who are low-income, less educated, and on Medicaid are less likely to receive professional guidance on dental care. This is particularly problematic because low-income children have higher rates of early childhood tooth decay and would benefit from early dental care," Clark says.

"Providers who care for at-risk populations should dedicate time to focus on the importance of dental visits. Parents should also ask their child's doctor or their own dentist about when to start dentist visits and how to keep their child's teeth healthy."

Punishing a wrongdoer may be more rewarding to the brain than supporting a victim. That is one suggestion of new research published in JNeurosci, which measured the brain activity of young men while they played a "justice game."

Study participants played a game in which two players -- a "Taker" and a "Partner" -- each start out with 200 chips. The Taker can steal up to 100 of the Partner's chips, and then the Partner can retaliate by spending up to 100 chips to reduce the Taker's stash by up to 300 chips. Participants played as either a Partner or an Observer, who could either punish the Taker or help the Partner by spending chips to increase the Partner's stash.

Mirre Stallen and colleagues found that participants were more willing to punish the Taker when they experienced injustice directly as a Partner as opposed to a third-party Observer. The decision to punish was associated with activity in the ventral striatum, a brain region involved in reward processing, and distinguishable from the severity of the punishment. Before beginning the experiment, all participants were given a nasal spray, with some randomly assigned to receive the hormone oxytocin, which has been suggested to have a role in punishing. Participants in the oxytocin group chose to give more frequent, but less intense, punishments. This finding implicates oxytocin in corrective punishments akin to a "slap on the wrist" to maintain fairness.

BOSTON -- (Feb. 19, 2018) -- Every cell in your body responds to the hormone insulin, and if that process starts to fail, you get diabetes. In an unexpected finding, scientists at Joslin Diabetes Center have identified four viruses that can produce insulin-like hormones that are active on human cells. The discovery brings new possibilities for revealing biological mechanisms that may cause diabetes or cancer.

"Our research may help open up a new field that we might call microbial endocrinology," says Emrah Altindis, PhD, a Joslin research fellow and lead author on a paper in the journal PNAS on the work. "We show that these viral insulin-like peptides can act on human and rodent cells. With the very large number of microbial peptides to which we are exposed, there is a novel window for host-microbe interactions. We hope that studying these processes will help us to better understand the role of microbes in human disease."

"Indeed, the discovery of the viral insulin-like hormones raises the question of what their role might be in diabetes, as well as autoimmune disease, cancer and other metabolic conditions," says C. Ronald Kahn, MD, Joslin's chief academic officer and senior author on the paper.

The key idea for the investigation came when Altindis, whose previous research focused on creating vaccines against bacteria, attended a Joslin seminar that discussed potential causes of the autoimmune reaction that drives type 1 diabetes. He began to hypothesize whether bacteria or viruses could create insulin-like peptides (small versions of proteins) that could help to trigger the disease.

By analyzing large public research databases that hold viral genomic sequences, he and his colleagues at Joslin found that various viruses can produce peptides that are similar in whole or in part to 16 human hormones and regulatory proteins.

"What really caught our attention were four viruses that had insulin-like sequences," says Kahn, who is also the Mary K. Iacocca Professor of Medicine at Harvard Medical School.

These viruses were from a family of viruses known to infect fish. To find out if they could be active in mammals, the Joslin team collaborated with Richard DiMarchi, professor of chemistry at Indiana University, whose lab chemically synthesized these viral insulin-like peptides (VILPs).

Experimenting in mouse and human cells, the scientists studied whether the VILPs could act like hormones. Their experiments proved that the VILPs could indeed bind to human insulin receptors and receptors for a closely related hormone called IGF-1 (insulin-like growth factor 1). These are the critical proteins on the cells that tell them to take up glucose and to grow. Additionally, the peptides could stimulate all of the signaling pathways inside the cells that were stimulated by human insulin and IGF-1. And mice injected with the viral peptides exhibited lower levels of blood glucose, another sign of insulin action. Moreover, analysis of databases of viruses found in the human intestine showed evidence that humans are exposed to these viruses.

"These viruses are definitely known to infect fish and amphibians, but they are not known to infect humans," Kahn points out. "However, it's possible that humans get exposed to these viruses through just eating fish. Nobody has checked directly whether under some conditions the viruses could either infect cells or be at least partly absorbed through the gut intestine."

The scientists now will broaden their search for other viruses that produce human-like hormones. "This finding is the tip of an iceberg," Kahn says. "There are thought to be more than 300,000 viruses that can infect or be carried in mammals, and only 7,500 or so of these, or about 2.5%, have been sequenced. Thus, we certainly expect to find many more viral hormones, including more viral insulins, in the future."

"This research also opens up a new aspect to study in type 1 diabetes and autoimmunity," he says. "It may be that these or similar microbial insulin-like molecules could be an environmental trigger to start the autoimmune reaction in type 1 diabetes. On the other hand, you could also imagine that this might desensitize the immune response and could be protective."

A similar question is open for metabolic diseases such as type 2 diabetes and obesity, in which the body fails to respond properly to insulin. "You could envision that these viral peptides could either protect from or contribute to insulin resistance," Kahn says.

These or similar viruses might also be a factor in certain human cancers. "If these viruses are inside the gut, could the VILPs they produce stimulate growth of gut cells so that you get polyps or tumors of the gut?" Kahn asks. "Or if they're absorbed or become infectious, could they infect any organ in the body?"

Analyzing such viral peptides may eventually help drug companies to design new forms of synthesized human insulins. "We might be able to learn something, for example, about making insulins that don't need refrigeration and can be stored for long periods of time, or insulins that are absorbed more quickly or degrade more slowly," he suggests.

Given Altindis's earlier research on infectious disease rather than in endocrinology, "our discovery gives an example of how work in one field can stimulate thought in another field," Kahn adds. "It really underlines the importance of cross-fertilization in the scientific discovery process, which is so valuable but so underappreciated."

Bees? Great. Ants? Hit or miss. Slime mold amoebas? Fail. Though nature offers excellent design inspirations in some information technology systems, in other systems, it can bomb.

Known for his work on The Honey Bee Algorithm, which tamed web traffic instabilities on servers by mimicking the behavior of bee colonies, systems researcher Craig Tovey has seen plenty of nature-inspired technological feats, but also foibles. He's sharing them in a talk on Sunday, February 18, at the annual meeting of the American Association for the Advancement of Science in Austin, Texas.

(To attend, see: "What Systems Engineers Can Learn from Honey Bees and Other Organisms, 4:30 p.m. Central, Austin Convention Center, room 18B.)

In 2016, the bee-inspired algorithm garnered Tovey and his collaborators a Golden Goose Award, which commends curiosity-driven research as it blossoms to palpably benefit society. The Honey Bee Algorithm, for example, significantly reduced web hosting costs.

"We lucked out with the bees and web hosting," said Tovey, who hopes that along with practical takeaways on naturally inspired technology, his audience will also share in his own awe and affection for nature's solutions.

When algorithms are eternal

"When you study swarming bees, you discover truths that are lasting. The algorithms that guide them evolved over millions of years, and will hopefully still be there for millions of years to come," said Tovey, a co-director of Georgia Tech's Center for Biologically Inspired Design. "Compare that with when you design a new microcircuit. Three years later it's gone, forever lost; replaced by new designs."

Whether mimicking nature is prudent in a particular engineering job depends a lot on the problem to be solved. Often, it's just better to use something off the shelf or adapt it.

"When the real-life problem is static and well-defined with predictable data, then the nature-inspired methods are usually much weaker, much worse than classical optimization methods," Tovey said.

When boring is better

The "Traveling Salesman Problem" is a typical example. A researcher tries to compute the best pathways a proverbial salesperson should travel, and in which order, to visit hundreds, thousands, or tens of thousands of proverbial cities on a map.

The goal is to travel the shortest possible total distance.

"Nature-inspired approaches will find good solutions for 100 or so cities, but not optimal ones,” said Tovey, who is also a professor and Stewart Faculty Fellow in Georgia Tech’s Stewart School of Industrial and Systems Engineering. “By contrast, the top researchers can solve 20,000 or 50,000 locations optimally with a classical algorithm, and do it really quickly."

When ants miss and hit

"People have imitated ants to find the optimal pathways through a static system, and when you compare that method with classical optimization methods, then the classical methods are about 10 billion times better."

But life is fickle, which can make it a great teacher in science and engineering. "Every living creature is very good at solving a number of different problems, otherwise it would have gone extinct," Tovey said.

Toss unpredictability into an engineering problem, and natural algorithms that direct the movements of ants or bees can be better equipped to cope than classical solutions.

"In the Traveling Salesman Problem, the cities don't move around. But when you're chasing a moving target, and your data isn't perfectly complete, then you can have great success by imitating insect swarms. You can get real-time control on data that's quite literally on the fly," Tovey said.

When bees know best

That counts for a lot in a pinch. When a hurricane looms, people check their weather apps much more frequently as the tempest encroaches. When markets tank, people sell off stocks, and data surges in and out of financial servers.

"If the patterns of user demand on the web never changed, and the requests to a server always stayed the same, all would be well without imitating honeybees," Tovey said. "But that notion is ridiculous, as we all know."

"Bees have evolved to deal with flower patches that have changing characteristics. A patch that is great to visit at 10 o'clock in the morning may have its flowers closed-up at one o'clock in the afternoon, or it may be raining."

Algorithms steering bee behavior make the insect swarms adjust to supply and demand fluxes similar to those that confront a web server. The honeybees handed Tovey and his fellow researchers valuable insights for their web hosting algorithm.

When slime flops but amazes

Though classic algorithms beat nature in simple situations, watching natural algorithms in even the simplest organisms can be awe-inspiring. Take slime mold, a non-cellular organism related to amoebas.

"If you put down lumps of food near it, the slime mold will extend to reach the lumps and connect them with each other."

The mold makes very efficient connections that adapt well to differing constellations of food dabs.

"Some researchers placed food sources in spots corresponding to the locations of cities in Japan that were connected by rail lines, and sure enough, the slime mold eventually settled on a configuration connecting the spots that nearly perfectly matched the rail network that actually connected the cities," Tovey said.

Again here, classic algorithms do the job better, but still, that slime is just amazing.

For all his awe of bees, Tovey has had to avoid making their acquaintance in person and leave the bee-handling to his collaborators. "I and my whole family are all extremely allergic to bee stings," Tovey said. "We keep EpiPens around the house."

AUSTIN, Texas -- Building on the success of 10 years of investigation into the production of renewable fuels from plants, the Great Lakes Bioenergy Research Center (GLBRC), led by the University of Wisconsin-Madison, recently embarked on a new mission: to develop sustainable alternatives to transportation fuels and products currently derived from petroleum.

On Feb. 18 at the Annual Meeting of the American Association for the Advancement of Science in Austin, Texas, Tim Donohue, GLBRC director and UW-Madison professor of bacteriology, highlighted a decade of developing economically viable bioenergy technologies, while looking forward to the next five years of establishing a production pipeline of advanced fuels and bioproducts.

When most people think of biofuel, it's a first-generation version of ethanol that comes to mind. Corn kernels, harvested for their sugar, are broken down and fermented at a refinery. The resulting product, ethanol, becomes 10 percent of what we put in our gas tanks.

When the U.S. Department of Energy's Bioenergy Research Centers were conceived just over ten years ago, GLBRC had a goal of turning more of the corn plant -- the stalk and leaves that makes up the stover -- into ethanol, while developing perennial plants like switchgrass and miscanthus (also called silvergrass) into potential feedstocks.

"The result was almost 1,100 publications, 154 invention disclosures, 168 U.S. and international patents applications, 89 licenses and options and five startup companies relating to improved biomass crops, plant deconstruction and the development of next generation catalysts and microbes for conversion," Donohue says.

Now, GLBRC is taking its mission one step further. Instead of producing ethanol, GLBRC's goal is centered on designing advanced biofuels, such as isobutanol. These "drop-in" fuels could be used to replace gasoline without engine modification. By engineering bioenergy crops to enhance their environmental and economic value, and conducting research to generate multiple products from plant biomass, these advancements could optimize the bioenergy field-to-product pipeline.

Breaking down the more complex biological components of woody biomass to extract the sugars for fermentation into fuel is one step of the process. James Dumesic, a GLBRC researcher and UW-Madison professor of chemical and biological engineering, found a way to do just that with gamma valerolactone, a chemical derived from plants themselves.

GLBRC scientists and engineers are also improving the yield and processing traits of dedicated bioenergy crops for cultivation on marginal, or non-agricultural, land. With smart management, these crops have the potential to benefit the ecosystem, help mitigate climate change, and provide farmers with an additional source of revenue.

Donohue's specialty at GLBRC is in studying how microbes can digest these broken-down pieces of the plant to produce valuable products.

"We're trying to re-task native pathways and engineer next-generation microbial factories that can manufacture valuable fuels and chemicals from renewable wastes," he says.

The oil industry isn't profitable merely because of production of fuel that keeps us warm and makes our cars go vroom. It's sustained by the production of almost 200 chemicals that go in everything from cosmetics to crayons, and from plastics to paper cups.

GLBRC is focused on enabling a new and different biorefinery, one that is both economically viable and environmentally sustainable. Realizing this goal will mean increasing the efficiency of biomass conversion and generating a mix of specialty biofuels and environmentally-friendly bioproducts, from as much of a plant's biomass as possible. One such discovery, breaks down lignin's six-carbon rings -- the "aromatics" -- into individual components. Traditionally sourced from petroleum, aromatics are used in a wide variety of products, including plastic soda bottles, Kevlar, pesticides, and pharmaceuticals, and are essential components of jet fuel.

"We are in a unique position to not only address a major societal challenge," Donohue says, "but to create new revenue sources and economic opportunities for farmers, rural communities and a new generation of bio-refineries."

WASHINGTON, D.C., Feb. 18, 2018 -- Phospholipids are water insoluble "building blocks" that define the membrane barrier surrounding cells and provide the structural scaffold and environment where membrane proteins reside. During the 62nd Biophysical Society Annual Meeting, held Feb. 17-21, in San Francisco, California, William Dowhan from the University of Texas-Houston McGovern Medical School will present his group's work exploring how the membrane protein phospholipid environment determines its structure and function.

There are two types of membrane proteins inside the phospholipid environment. "Hydrophilic (water-loving) are exposed on the membrane surface where they stably interact with the aqueous environment surrounding membranes, and hydrophobic (water-repelling) are exposed to the interior of membranes," Dowhan said.

Because of this balance of hydrophilic and hydrophobic proteins on the inside and outside side of the cell membrane, the conditions remain stable. "For example, the hydrophilic (proteins) on one side of the membrane shouldn't flip through the hydrophobic core of the membrane to the other side," Dowhan said.

This made Dowhan wonder why "cells maintain thousands of unique phospholipid species." To find out, his group constructed mutants of the bacterium Escherichia coli and the yeast Saccharomyces cerevisiae in which the composition of these "building blocks" could be varied. "As we varied the membrane phospholipid composition, we adversely affected cellular functions." Dowhan said.

These are significant findings, because "membrane proteins are initially made in the endoplasmic reticulum (inside cell), then transported to other membranes where they function," Dowhan said. "So, a change in phospholipid environment during this transport process ... within a membrane, can change a protein's structure and function. The importance of dynamic changes in membrane protein function related to phospholipid composition is an unrecognized way of controlling cellular processes."

How cells regulate various processes is central to maintaining cell viability, and it's a unique property of each cell type. "To fully understand life, we not only need to define each chemical reaction within a cell but also how each is regulated and integrated with each other," Dowhan said.

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Animal traffickers are taking advantage of remote ivory trade routes to smuggle pangolins - one of the world's most endangered animals - out of Central Africa, a new study has found.

The solitary mammals - sought after for their meat and scales - are being transported across remote forest borders in a largely successful attempt to avoid increased law enforcement, according to groundbreaking research led by the University of Stirling.

In the first ever study to investigate how criminals are sourcing pangolins from African forests, experts found that local hunters in Gabon are selling increasing numbers of the animals to Asian workers stationed on the continent for major logging, oil exploration and agro-industry projects.

In another significant finding, the team discovered that the price for giant pangolins has risen at more than 45 times the rate of inflation between 2002 and 2014.

The study is published in the African Journal of Ecology today, World Pangolin Day, and experts believe it will help law enforcers tackle the increasing problem.

Dr Katharine Abernethy, of the Faculty of Natural Sciences, led the work, which also involved the University of Sussex, Gabonese researchers and other industry partners.

"This is the first study of how illegally traded pangolins may be being sourced from African forests and it shows that the high value paid internationally for large giant pangolin scales is probably affecting their price, even in very remote villages," Dr Abernethy said.

"However, local subsistence hunters are probably not the primary suppliers - this is likely to be criminal hunting organisations, possibly those who are also trading in ivory in the region, as the demand markets are similar."

Found in Asia and Africa, pangolins are scaled, primarily nocturnal animals, which feed predominantly on ants and termites. The eight species of pangolin range from vulnerable to critically endangered, with their meat and scales in high demand, especially in Asia.

With the decline of the Asian species in recent years, there has been a significant increase in the number of African pangolins seized in Asia. Consequently, in 2016, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - a multilateral treaty to protect endangered plants and animals - banned all international trade in the African species in a bid to restrict wildlife losses.

The new study focused on Gabon, in Central Africa, where, as in many other countries, domestic hunting and eating of certain species of pangolin is legal.

The team visited communities using pangolins and other wildlife for food, as well as markets in provincial towns and the capital, Libreville, to assess the numbers sold and prices. They found that the relative value of pangolins has increased significantly since 2002 - more than the price for other species and higher than expected under inflation. In Libreville, giant pangolin prices increased 211 per cent over the period, while arboreal pangolin prices rose 73 per cent - despite inflation going up by just 4.6 per cent.

People with Asian connections were significantly more likely to ask for pangolins than any other species, the researchers found. However, illegally-traded pangolins were not detected by law enforcers controlling traditional meat trade chains, but found associated with ivory trading across forest borders.

The study concluded that the high international price of scales was driving up local costs, with hunters increasingly targeting pangolins to sell them on, rather than for home consumption.

Dr Abernethy said: "We conclude that whilst there is clear potential and likelihood that a wild pangolin export trade is emerging from Gabon, traditional bushmeat trade chains may not be the primary support route.

"We recommend adjusting conservation policies and actions to impede further development of illegal trade within and from Gabon.

"As in the ivory trade, law enforcement and international efforts to save pangolins need to target specialised criminal hunters, rather than putting pressure on the subsistence community."

Daniel Ingram, who was involved in the research whilst at the University of Sussex, said: "We are still learning about the scale of trafficking in pangolin meat and scales but every new finding adds very concerning new details about this trade.

"The link between Asian industrial workers working on major projects in Africa and requests for pangolins is worrying, and warrants further investigation."