Earth

Thanks to photos and films featuring clouds of stunning orange and black monarch butterflies flying across North America, many people today are familiar with how monarchs migrate. The migration patterns of other insects, however, remain more mysterious, for both the public and scientists alike. A new paper in Biology Letters describes a dragonfly's full life cycle for the first time, in compelling detail.

The researchers explain how the common green darner--a large, abundant dragonfly found across North America--takes three generations to complete its annual cycle. One generation migrates north in spring, the second south in fall, and the third is resident in the southern part of the species' range over winter. These insects have a wingspan of just 7.5 cm (3 inches), but they migrate an average of over 600 km (373 miles), with some individuals covering more than 2,500 km (1,553 miles).

"We know that a lot of insects migrate, but we have full life history and full migration data for only a couple. This is the first dragonfly in the Western Hemisphere for which we know this," says Colin Studds, assistant professor of geography and environmental systems at University of Maryland, Baltimore County (UMBC) and senior author on the paper. "We've solved the first piece of a big mystery."

The common green darner is indeed very common, and not currently a threatened species. Understanding their life cycle is important, though, because of the global context. "There are massive insect declines going on around the world," says Peter Marra, director of the Smithsonian Migratory Bird Center and second author on the paper, "so understanding these complex biological patterns is essential to determine why different populations might be declining."

Insects are a critical driver of food webs, so figuring out why their populations are falling dramatically is important for the future success of a wide range of species, from rodents to raptors.

The research team used a combination of data sets, including 21 years of citizen science data, more than 800 dragonfly wing specimens from museums going back 140 years, and specimens caught in the wild. Collaborators Kent McFarland and Sara Zahendra of the Vermont Center for Ecostudies spent nearly two years collecting dragonflies from Florida to Ontario, Canada, and working with museums to get permission to analyze their specimens.

The team's creative analysis included looking at the prevalence of different forms of hydrogen in the dragonflies. The ratio of three forms of hydrogen in the atmosphere shifts with latitude. Dragonflies pick up an imprint of the hydrogen ratio at their birthplace, so a scientist can determine where a dragonfly came from by looking at how much of each hydrogen type is present in a tiny piece of the dragonfly's wing. That information enabled the team to discern the three-generation migration system.

The citizen science data--information collected by members of the general public--helped the scientists learn what factors cue the dragonflies to migrate or to emerge as flying adults after their aquatic juvenile stage. It turns out temperature plays a big role: the dragonflies both emerge and initiate migration at around 9 degrees Celsius (48 degrees Fahrenheit).

"With climate change we could see dragonflies migrating north earlier and staying later in the fall, which could alter their entire biology and life history," says Michael Hallworth, postdoctoral fellow at the Smithsonian Migratory Bird Center and first author on the paper. Studds adds, "Climate change is a threat to all kinds of migration systems, and this could be one of them."

Studds emphasizes that this discovery is the beginning of a long path toward better understanding insect migrations. Revealing the three-generation process, with two migratory generations and one resident, was, itself, "remarkable," he says. "How it actually happens is a tremendous new mystery that brings together ecology and evolution," Studds reflects, "and there's a lot more to understand."

Hamilton, ON (December 18, 2018) - Where you live in Canada may play a role in your risk of major diseases like cardiovascular disease, diabetes and cancer.

Researchers at McMaster University have identified trends linking health and lifestyle factors like access to public transit, the variety of fresh fruits and vegetables in grocery stores, the prices of popular foods, the availability and prices of cigarettes and alcohol, and the promotion, or lack thereof, of healthy foods in restaurants.

The study findings, based on detailed data collected across Canada's 10 provinces, were published today in the journal Cities and Health. An interactive online map for public use showing the data by postal code is available at: http://cvcdcontextual.mcmaster.ca.

"We found there are significant differences in environmental factors that may contribute to health, and that these differed between urban and rural communities, as well as when we compared eastern with western, and northern with southern communities," said Russell de Souza, first author of the study and assistant professor in the Department of Health Research Methods, Evidence, and Impact at McMaster.

He is also a research associate at the Population Health Research Institute (PHRI) of McMaster and Hamilton Health Sciences.

"We believe that this information shows there are factors outside of a person's control that influence the individual's health, and these factors likely differ depending on where they live."

The main findings of the study are:

provincial and urban-rural differences exist in availability of fruits and vegetables, and advertising differs between provinces more so than between urban and rural communities;

rural communities face higher food prices, are more subject to seasonal variation in fruit and vegetable selection, and generally see less promotion of healthy restaurant options and availability of nutritional information at restaurants than urban communities;

in-store advertising for sweet drinks, and junk food are more frequent than in-store advertisements for tobacco products;

cigarette prices are lower and the variety of brands is greater in urban than in rural tobacco stores; and are lowest in central Canada, where there is both more in-store advertising for cigarettes and signage prohibiting smoking in stores; and

alcohol prices are lowest in Quebec.

More than 2,000 on-the-ground assessments conducted in all of the provinces were collected by trained auditors between 2014 and 2016. The assessment tool was adapted from the McMaster-led Prospective Urban and Rural Epidemiological (PURE) study that simultaneously assesses multiple contextual factors within communities and has been used internationally.

De Souza said the research was driven by concern about health trends in the nation.

"The rapid increase of overweight and obese Canadians and the associated consequences, including hypertension and diabetes, is a major health problem and threatens to halt the declines in cardiovascular disease deaths that Canada has experienced in the past 30 years," said de Souza.

"Knowledge gaps exist regarding the impact of the built environment - or the human-made physical surroundings - on how someone develops risk factors like high blood pressure, and the variation of these built environments across Canada by region and rurality."

The researchers were unsurprised to find that the environmental factor trends aligned with health outcomes tracked in other studies.

"Previous Canadian studies have shown that people living in the east have a higher risk of developing heart disease than people living in the west," said de Souza.

"We also see people who live in rural environments tend to have poorer health than people who live in urban environments.

"This study helps us to understand what we call the 'causes of the causes' of diseases like cardiovascular disease. For example, what are the factors that lead to the development of high blood pressure, which can later lead to a stroke or high cholesterol, which later turns into a heart attack?"

De Souza said the researchers decided at the start of the study the data would be presented in an online, interactive map to convey the information from the community contextual health audits.

"We think presenting our data in this way offers a platform for policy makers, public health professionals and community members to collaborate to build healthier environments and fix the problems," de Souza said.

"By understanding how the built environment plays a role, we can intervene both at an individual level, as well as at a community level. It's one thing for your doctor to tell you that you need to eat more fruits and vegetables to lower your blood pressure, but what if your grocery store prices are so high that you cannot afford them? Or if to get to your grocery store, you have to drive for 30 minutes? If five to 10 servings of fruit and/or vegetables are recommended daily, we should advocate for everyone to be able to afford and access those servings."

The study was a component of the Canadian Alliance for Healthy Hearts and Minds (CAHHM), led by Sonia Anand, professor of medicine at McMaster, senior scientist of PHRI, and vascular medicine specialist at Hamilton Health Sciences.

CAHHM is a multi-ethnic cohort study being conducted in Canada. The study aims to understand the association of socio-environmental and contextual factors, such as societal structure, activity, nutrition, social and tobacco environments, and access to health services, in relation to risk factors of cardiovascular and other chronic diseases.

"This study is unique because it will enable comparisons between communities within a region, province, and across the country. Place matters as our environment affects our health behaviours without our realizing it," said Anand, the Heart and Stroke Foundation / Michael G. DeGroote Chair in Population Health Research McMaster.

"We are making these data available to other researchers and health planners so they can further quantify the impact of the built environment on health, and to help in the building of healthier communities," she added.

As for the best place to live in Canada's 10 provinces based on study results, de Souza said it depends on your health habits and preferences.

"I would want to live somewhere that makes it easiest to change any behaviour that may be harming my health," he said. "For example, if I were a smoker, I would want to live in a place where it was hard for me to get cigarettes. If I were having a difficult time eating healthy, I would want to live somewhere where it was easy for me to walk to a grocery store and buy affordable fresh fruits and vegetables."

De Souza noted the three territories were not included in the study due to geographical limitations for the research team.

The CAHHM project is funded by Canadian Partnership Against Cancer, Heart and Stroke Foundation of Canada, and the Canadian Institutes of Health Research (CIHR) through the Canadian Urban Environmental Health Research Consortium.

Anne Simard, chief mission and research officer of the Heart and Stroke Foundation of Canada, said: "This study demonstrates that rural, including northern and remote communities continue to face inequities with respect to access to healthy food options and even nutrition information in restaurants. This underscores the need for policies to improve nutrition in these communities."

Craig Earle, vice president of cancer control with the Canadian Partnership Against Cancer, added: "The importance of these findings is that they highlight disparities that contribute to different health outcomes depending on where you live. There are things we can collectively take action on today."

In a review of registry data for more than 5,300 liver transplants performed in children nationwide, Johns Hopkins Medicine researchers identify the type of patient who is most likely to survive a split liver transplant--receiving only part of a donor's liver--with no additional long-term health risks, which could allow for an increase in the availability of organs. A report on the new study is published in the December issue of the journal Liver Transplantation.

"Kids dying while on the waitlist is the worst possible outcome," says Douglas Mogul, M.D., Ph.D., medical director of the Pediatric Liver Transplant Program at Johns Hopkins Children Center and assistant professor of pediatric gastroenterology, hepatology and nutrition at the Johns Hopkins University School of Medicine.

Split liver transplants have been performed for nearly 30 years, according to Mogul, and using the liver's natural structure, a split liver transplant can use a 35 to 40 percent section, making split liver transplant ideal for children whose smaller weights accommodate smaller livers. "An SLT essentially could allow two transplants from a single liver," says Mogul.

Using data from the Scientific Registry of Transplant Recipients, Mogul, colleague Dorry Segev, M.D., professor of surgery at the Johns Hopkins University School of Medicine, and their teams examined the medical records of 5,345 pediatric patients who had received their first--either split or whole--liver transplant in the United States between March 2002 and December 2015.

"We already knew from previous studies that variables including the donor's age and cause of death along with the health of the recipient can influence outcomes," says Mogul. "But understanding which of these variables could impact the outcomes from transplanting a split liver versus a whole liver could help guide the increased use of split livers and identify which patients will do best after split or whole liver transplants, thereby being more strategic about matching donor organs with recipients."

Using a statistical analysis that relates variables with an event or outcome, the team looked at the relationship between the type of liver--split or whole--and transplant success after adjusting a number of variables, including many that had previously been reported as influencing organ transplant success. Those variables included organ donor age, cause of death, recipient weight at transplant, underlying disease and how sick the recipient is.

Of the 5,345 pediatric liver recipient records examined, 1,694 or roughly 31 percent received a split liver while 3,651 or roughly 68 percent received a whole liver. Split liver recipients were less likely than whole liver recipients to receive an organ from another pediatric patient, 59 percent versus 83 percent, respectively, and more likely to have received their liver from a donor between ages 18 and 50, 38 percent versus 13 percent, respectively. Split liver recipients were less likely than whole liver recipients to have a donor who suffered from lack of oxygen, but more likely to have a donor with head trauma.

On the surface, it appears that split liver transplants fared worse. However, after adjusting the data for donor age, recipient weight, other recipient health problems as well as surgical approach, there was no difference in outcomes for split versus whole liver recipients. More importantly, what the team found was that groups defined by certain characteristics that had the highest overall transplant failure were actually not further negatively impacted by having a split versus whole liver, implying that these sickest children would be good candidates for split livers. "One might anticipate that patients with the highest likelihood of graft failure would do worse if they got a split compared to a whole. But we saw the opposite: These people were not further impacted by getting a split," says Mogul.

Recipients who weighed less than 10 kilograms had higher rates of transplant failures in general, regardless of whether they received split or whole livers; suggesting that body weight less than 10 kilograms may be a factor for considering split liver transplantation. In contrast, recipients who weighed between 10 and 35 kilograms had an overall lower risk of transplant failure, but the failure rate after receiving a split liver was 1.46 times that of receiving a whole liver, suggesting recipients in this weight range should be considered for whole livers.

Overall, Mogul says, waiting children with lower body weights, who were in relatively worse health and whose donor livers spent more time on ice or in transit, had the same potential for a successful transplant with a split liver as they would have with a whole liver. The researchers estimate that 22 children on the liver transplant list could have benefited from split liver transplant but instead died while waiting.

"We hope these findings can help guide surgical decision-making and support policy changes that promote the increased use of SLT for selected children," says Mogul. From their study, optimal recipients could include children weighing under 10 kilograms, with a rare disease of the bile ducts known as biliary atresia, acute hepatic necrosis or sudden liver death, autoimmune disease and tumor.

"The better understanding of SLT learned from this study and our most recent research is a critical step toward the goal of significantly increasing access to transplantation," says Segev. "If they wanted to, UNOS--the United Network for Organ Sharing, the entity responsible for U.S. organ allocation policies--could institute policies within one to two years that would have huge impacts on children waiting for liver transplants."

Climate change threatens plants as the risks of flooding increase. A new study from Stockholm University shows that special genes are key to keeping plants from withering, remaining healthy and resistant to a lack of oxygen when they are underwater for a period of long time. Developing tolerant plant varieties that have this gene will increase harvest and will be increasingly important as the changing climate leads to more rainfall.

Plants, like humans, are deprived of oxygen when underwater. Sylvia Lindberg, professor at Stockholm University, investigates how plants become more resistant to surviving this oxygen deficiency. When plants lack oxygen, special genes signal danger and that the plant must activate other genes to help defend itself. One of these genes is PLD, which forms the enzyme phospholipase D. Until now, the key role it plays in the plants' oxygen deficiency signal systems was unknown.

"We suspected that this gene was involved, as it is in other types of stress that plants are exposed to, for example, high salinity, cold, drought and fungal infection", says Professor Sylvia Lindberg.

When plants are deprived of oxygen, they grow less, and their leaves turn yellow. Sylvia Lindberg and her research team used mutant plants that lacked the potentially protective gene to see if it was worse off during a simulated flood. The study showed that the leaves of the mutant plants turned yellow and died - meaning that the gene plays a role in keeping the plant in good health.

"We are studying the plant rockcress, Arabidospis, which is a common model plant because all genes are identified for it", says Sylvia Lindberg.

Some of the plant mutants produced less calcium compared to the wild plant, when exposed to a lack of oxygen. It is therefore possible that the amount of calcium also protects the plant. Calcium is an important signal substance that increases within the cells for all types of stress that were examined.

"For example, rice is very tolerant to oxygen deficiency and increases its cellular calcium levels much more than wheat does, which is highly sensitive to oxygen deficiency and does not increase its calcium levels to the same extent. So, crops vary in how vulnerable they are to oxygen deficiency", says Sylvia Lindberg.

The plant mutants also produced less phosphatidic acid, which is also an important second messenger during times of stress in plants. The next step is to investigate how the plants would react to oxygen deficiency if you instead rise the amount of the modified gene PLD.

"Then maybe more protective calcium and phosphatidic acid will be formed to counteract the effect of oxygen deficiency. I hope more research will be done in this area. It is real detective work but important for developing new tolerant crops", says Sylvia Lindberg.

A first-of-its-kind retrospective study concludes that environmental cleanup projects can provide high value to society, making them economically viable alternatives to coastal development projects. The analysis of Boston Harbor suggests the capitalized value of restored ecosystem services now stands at between $30 and $100 billion -- far outweighing the $5 billion cleanup cost. Published in Frontiers in Marine Science, the study demonstrates that the post-cleanup value of healthy ecosystems and their associated benefits should be considered when evaluating options for coastal areas.

"The Boston Harbor cleanup led to a significant increase in private investment, and economic growth along the waterfront has outpaced the city's overall rate of increase," says Dr Di Jin, lead author of the study from the Woods Hole Oceanographic Institution, USA. "This shows that we need to give more consideration to ecosystem service benefits when evaluating policy options."

Boston Harbor was infamous as 'the dirtiest harbor in America.' By the 1980s, heavy pollution from raw sewage and wastewater discharges had severely constrained recreational activity, affected marine habitat and left water quality poor. Following a court-ordered re-vamp in 1986, a new treatment plant was constructed and various cleanup projects were undertaken -- which turned the filthy harbor into the 'Great American jewel' it is known as today.

The cleanup -- which was never expected to be cost-effective -- gave researchers a rare opportunity to retrospectively analyze the profitability of a completed environmental restoration.

"Most environmental cleanup cost-benefit analyses are for proposed future projects, using projected benefits rather than known outcomes," says Jin. "Decision makers consider the value of an area at the time of proposal, when the area is most polluted, rather than the value an unpolluted area could have post-cleanup."

By assuming polluted coastal areas offer little value to society, such analyses often lead to industrial or residential developments being favored over environmental cleanup projects.

Dr Jin and colleagues wanted to demonstrate the importance of considering the environmental value of an area post-cleanup rather than pre-cleanup.

They studied the healthy ecosystem that Boston Harbor is today, compared to how it was at its most polluted when the original cost-benefit analyses were conducted.

To do so, the researchers developed an economic evaluation model based on the value of services that healthy ecosystems can provide to society. It works by considering each type of land cover in a study area -- such as beaches, salt marshes and oyster beds in the case of Boston Harbor -- and estimating the overall value that each ecosystem in the area can have. For example, the value of clean water includes being able to support fish stocks as well as coastal recreational activities.

Using the model, the researchers estimated the current ecosystem value of Boston Harbor at between $30 and $100 billion dollars.

"The costly project used almost 5 billion dollars of taxpayers' money," says Jin. "Yet this represents just 5%-16% of the total capitalized value of the ecosystem."

The authors hope their work highlights the potential benefits of environmental cleanup and ecosystem restoration.

"Pollution control and cleanup is a common challenge facing many urban harbors around the world," says Jin. "We hope that our study will provide useful information to decision makers and the public facing similar decisions on the viability of ecosystem restoration projects."

More than one in eight U.S. adults (12.6 percent) used benzodiazepines in the past year, up from previous reports. Misuse of the prescription drugs accounted for more than 17 percent of overall use, according to a study published online today in Psychiatric Services in Advance. The researchers defined misuse as any way a doctor did not direct, including using the drug without a prescription or more often or longer than prescribed. Misuse was highest among young adults 18 to 25 (5.6 percent) and was as common as prescribed use.

Benzodiazepines are a class of medications used to treat conditions such as anxiety and insomnia. They include Alprazolam (Xanax, Niravam) diazepam (Valium), clonazepam (Klonopin), lorazepam (Ativan) and others. Researchers analyzed data from the 2015 and 2016 National Survey on Drug Use and Health.

Although there were differences in the studies, research from 2013 and 2014 found about 4 to 6 percent of adults used benzodiazepines. Previous national estimates of use have not accounted for misuse. In addition to finding that overall use has increased, today's study is the first analysis to find the highest benzodiazepine use among adults 50 to 64 years (13 percent); previous studies found the highest use was among those 65 and older. Whereas women were more likely than men to report any use of benzodiazepines, men were more likely than women to report misuse. Benzodiazepine use has come under increasing scrutiny given the associated harms and safer alternatives, particularly in light of the opioid epidemic. The study found benzodiazepine misuse was strongly associated with misuse of or dependence on prescription opioids or stimulants.

When asked about the reasons for misuse, nearly half said to relax or relieve tension and just over a quarter said to help with sleep. Among people taking benzodiazepines without a prescription, the most common source was a friend or relative.

The authors, led by Donovan Maust, M.D., with the University of Michigan, Ann Arbor, suggest that patients also prescribed stimulants or opioids should be monitored for benzodiazepine misuse. They also note that some misuse may reflect limited access to health care generally and behavioral treatments specifically and suggest that some misuse could be reduced with improved access to behavioral interventions for sleep or anxiety.

Ann Arbor, December 17, 2018 - A new study published in the American Journal of Preventive Medicine provides detailed insights on the increased risk of self-directed violence that patients aged 15-29 years visiting the emergency department (ED) for medical complaints subsequently experience. This underscores the importance of EDs in suicide prevention. The broad number of physical health conditions associated with an increased risk of self-directed violence may serve to support expanded or broader screening among teens and young adults.

Suicide is the second leading cause of death for youth, with mental disorders and substance abuse as the two leading risk factors. Approximately 40 percent of suicide decedents aged 16 and older visit EDs in the year prior to their deaths; 60 percent of them receive medical diagnoses other than mental health or substance abuse.

"Young people presenting to the ED for certain medical conditions are at an increased risk of subsequent self-directed violence," explained lead investigator Jing Wang, MD, MPH, Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA, USA, in the study's findings. "An awareness of these medical encounters may help guide screening efforts for suicide prevention in clinical settings."

This study addresses important gaps in prior research by identifying the medical reasons triggering youth ED visits that are associated with higher risk of subsequent suicidal behavior. Using 2011-2013 data from six states (Florida, New York, Nebraska, Vermont, Iowa, and Massachusetts) from databases sponsored by the Agency for Healthcare Research and Quality, investigators followed more than two million teens and young adults (aged 15-29) who visited EDs for medical reasons during 2012-2013. Of that group, nearly 8,500 subsequently engaged in self-directed violence within six months of the initial visit; anyone who exhibited suicidal behavior in 2011 was excluded from the study.

Teens and young adults who presented with diagnoses of epilepsy or seizures, or visited two or more times for various types of pain, syncope (fainting), or vomiting had a 3-9 fold increased risk of suicidal behavior in the following six months. Individuals who visited three or more times for dental complaints were also found to be more likely to engage in subsequent self-directed violence. ED visitors in the group who received diagnoses of minor infections served as a reference group.

The findings also showed that half of the self-directed violence events occurred within 42 days of the initial ED visit. Identification of the heightened risk for suicide following visits for these medical conditions provides ED clinicians with a critical window of opportunity for detection, assessment, and intervention. The broad number of physical health conditions associated with an increased risk of subsequent suicidal behavior may help inform and support expanded screening and suicide prevention strategies in EDs.

A limitation of the study is that about 70 percent of people who engage in self-directed violence do not seek medical assistance.

Children of parents who have alcohol use disorder are more likely to get married under the age of 25, less likely to get married later in life, and more likely to marry a person who has alcohol use disorder themselves, according to a new study by researchers at Virginia Commonwealth University and Lund University in Sweden.

"There are many pathways through which a parent's alcohol problems can influence our own risk for alcohol problems. One important pathway, of course, has to do with the genes that parents pass to their children," said the study's lead author, Jessica E. Salvatore, Ph.D., an assistant professor in the Department of Psychology in the College of Humanities and Sciences at VCU. "But another important pathway, which we demonstrate here, is through the social environment."

The study, "Parental Alcohol Use Disorder and Offspring Marital Outcomes," was published in the most recent issue of the journal Addiction. It is based on data from legal, medical and pharmacy registries with detailed information on 1.17 million people in Sweden who were born between 1965 and 1975.

"Although there have been many studies along these lines in the past, there were some key methodological limitations to these prior studies, including the reliance on small samples," Salvatore said. "We were able to leverage the Swedish national registries to look at these questions in a large sample of over 1 million people."

The researchers set out to discover if alcohol use disorder (AUD) -- which affects an estimated 16 million people in the United States -- among parents would predict their adult offspring's likelihood of marriage and marriage to a spouse with alcohol use disorder.

"We know from previous research that who you marry plays a big part in whether you develop an alcohol problem," Salvatore said. "What we found in this study is that who you marry is not random -- and, in fact, the people who are at greatest risk for developing an alcohol problem (because they have an affected parent) are most likely to end up with a spouse who is going to exacerbate this risk."

Researchers found that parental alcohol use disorder is associated with a higher probability of marriage at younger ages, a lower probability of marriage at older ages and a higher likelihood of marriage to an affected spouse compared with no parental alcohol use disorder.

"In this case, we found that you do marry someone who is like your parents," Salvatore said.

The researchers also found that most of these effects become stronger when the number of parents with alcohol use disorder increases from one to two. Most effects also held after statistically controlling for parents' socioeconomic status, marital history, other externalizing disorders, and the offspring's own alcohol use disorder status.

Additionally, daughters of affected mothers are more likely to have an affected spouse, the researchers found.

The researchers were interested in their findings because previous research has shown that forming and maintaining romantic relationships with "prosocial" spouses reduces one's risk of developing alcohol use disorder.

"And what we find here is that people who are at risk of developing AUD (by virtue of growing up with an AUD-affected parent) are less likely to find themselves in these types of protective marital environments," Salvatore said.

From a practical standpoint, she said, the study's findings could be useful for clinicians and others who work with the offspring of parents with alcohol use disorder to raise awareness of how parental AUD can influence the types of social environments that can increase one's risk for alcohol use disorder.

"There are large international organizations, like Al-Anon and Alateen, that are geared towards helping and supporting the family members, and in particular children of people affected by alcohol use disorders," Salvatore said. "I think that there is a role for findings like ours as part of these types of family education programs. Specifically, becoming aware of how a parent's alcohol problem might shape one's own likelihood of ending up in the kind of marriage that will increase risk for alcohol problems may help people choose differently."

ANN ARBOR--A new electronic device can developed at the University of Michigan can directly model the behaviors of a synapse, which is a connection between two neurons.

For the first time, the way that neurons share or compete for resources can be explored in hardware without the need for complicated circuits.

"Neuroscientists have argued that competition and cooperation behaviors among synapses are very important. Our new memristive devices allow us to implement a faithful model of these behaviors in a solid-state system," said Wei Lu, U-M professor of electrical and computer engineering and senior author of the study in Nature Materials.

Memristors are electrical resistors with memory--advanced electronic devices that regulate current based on the history of the voltages applied to them. They can store and process data simultaneously, which makes them a lot more efficient than traditional systems. They could enable new platforms that process a vast number of signals in parallel and are capable of advanced machine learning.

The memristor is a good model for a synapse. It mimics the way that the connections between neurons strengthen or weaken when signals pass through them. But the changes in conductance typically come from changes in the shape of the channels of conductive material within the memristor. These channels--and the memristor's ability to conduct electricity--could not be precisely controlled in previous devices.

Now, the U-M team has made a memristor in which they have better command of the conducting pathways.They developed a new material out of the semiconductor molybdenum disulfide--a "two-dimensional" material that can be peeled into layers just a few atoms thick. Lu's team injected lithium ions into the gaps between molybdenum disulfide layers.

They found that if there are enough lithium ions present, the molybdenum sulfide transforms its lattice structure, enabling electrons to run through the film easily as if it were a metal. But in areas with too few lithium ions, the molybdenum sulfide restores its original lattice structure and becomes a semiconductor, and electrical signals have a hard time getting through.

The lithium ions are easy to rearrange within the layer by sliding them with an electric field. This changes the size of the regions that conduct electricity little by little and thereby controls the device's conductance.

"Because we change the 'bulk' properties of the film, the conductance change is much more gradual and much more controllable," Lu said.

In addition to making the devices behave better, the layered structure enabled Lu's team to link multiple memristors together through shared lithium ions--creating a kind of connection that is also found in brains. A single neuron's dendrite, or its signal-receiving end, may have several synapses connecting it to the signaling arms of other neurons. Lu compares the availability of lithium ions to that of a protein that enables synapses to grow.

If the growth of one synapse releases these proteins, called plasticity-related proteins, other synapses nearby can also grow--this is cooperation. Neuroscientists have argued that cooperation between synapses helps to rapidly form vivid memories that last for decades and create associative memories, like a scent that reminds you of your grandmother's house, for example. If the protein is scarce, one synapse will grow at the expense of the other--and this competition pares down our brains' connections and keeps them from exploding with signals.

Lu's team was able to show these phenomena directly using their memristor devices. In the competition scenario, lithium ions were drained away from one side of the device. The side with the lithium ions increased its conductance, emulating the growth, and the conductance of the device with little lithium was stunted.

In a cooperation scenario, they made a memristor network with four devices that can exchange lithium ions, and then siphoned some lithium ions from one device out to the others. In this case, not only could the lithium donor increase its conductance--the other three devices could too, although their signals weren't as strong.

Lu's team is currently building networks of memristors like these to explore their potential for neuromorphic computing, which mimics the circuitry of the brain.

EAST LANSING, Mich. - Hundreds of dams are being proposed for Mekong River basin in Southeast Asia. The negative social and environmental consequences - affecting everything from food security to the environment - greatly outweigh the positive changes of this grand-scale flood control, according to new research by Michigan State University.

The results, published in the current issue of Scientific Reports, are the first to tackle the potential environmental changes that the overall basin could experience from harnessing the region's hydropower.

"The Mekong River is one of the few large and complex river systems that remains mostly undammed," said Yadu Pokhrel, assistant professor of civil and environmental engineering and the study's lead author. "However, the rapid socio-economic growth, increasing energy demands and geopolitical opportunities have led to basin-wide construction of large hydropower dams."

In the basin's upper portion, dozens of mega dams are in the process of being built. In the lower region, hundreds of tributary dams are planned, and some larger ones also are being constructed.

While there are many positive effects of flood control, the researchers focused on the reduction of monsoon-driven floods that would be held back by the dams. These annual pulses provide much-needed water and nutrients to downstream regions.

"Any major alterations of the seasonal pulses could easily change the area's floodplain dynamics," Pokhrel said. "This could severely affect a wide range of ecosystems and undermine regional food security."

One waterway in particular, the Tonle Sap River that connects the Mekong River and Tonle Sap Lake, is one of the world's most-productive freshwater fisheries. Monsoons flood the Tonle Sap and actually reverse the river's flow each year. This brings water and sediments from the Mekong River into the Tonle Sap River as well as Tonle Sap Lake.

During the dry season, the flow normalizes and the lake drains into its namesake river, which eventually dumps into the Mekong River.

"Flow regulations could disrupt the flood dynamics of the Tonle Sap River," Pokhrel said. "In fact, our models indicate that TSR flow reversal could cease completely if the Mekong River flood pulse is dampened by 50 percent and delayed by one month."

The team of MSU scientists who were part of this study included Sanghoon Shin, Zihan Lin and Jiaguo Qi. Dai Yamazaki, from the University of Tokyo, also contributed to this research.

A study led by Prof. Juan Casado, from the Department of Physical Chemistry of the UMA, in collaboration with the University of Oregon (U.S.A.) and Osaka (Japan), which has proved that lone pair electrons that characterize sulfur atom can also repel unpaired or itinerant electrons that are present in their environment.

"This study evidences that the conventional conciliatory behavior of sulfur -electron donor- also shows a hostile side", explains the researcher from the UMA, who adds that these findings demonstrate that sulfur, under some circumstances, can also cause "magnetic repulsion".

Organic diradicals

According to this expert, the diradical molecules (a molecular species with two electrons occupying two "degenerated" molecular orbitals) used in the study -more stable, functional and durable- are critically important in chemistry, as well as in other sciences. For instance, they are associated with the chemical reactivity in combustion or are present in the persistence cycles of tropospheric ozone, and, also, in the future, they will be part of "magnetic plastic".

Whether by land or by sea, mammals live in a diverse variety of protective skins adapted against the elements, from swimming in the deepest azure oceans to climbing precipitous mountain peaks.

Now, Medical University of Vienna professor Leopold Eckhart and colleagues have performed one of the largest comparative genomic studies to help determine the key molecular and evolutionary origins of mammalian adaptations seen in skin proteins.

In a new study appearing recently in the advanced online edition of the journal Molecular Biology and Evolution, Eckhart's team homed in on which genes, among the dozens of mammalian keratin genes, are required for living on land or in the sea. The products of these keratin genes assemble to form the girders of the cytoskeleton in skin cells, called keratinocytes, that maintain a tight barrier between the body and the outside world.

"The results of the present study provide important new data on the evolution of keratins that control the mechanical stability of the epidermis, the outermost layer of the skin," said Eckhart.

In terrestrial mammals, the epidermis depends on different keratins to maintain the barrier to the environment and to regenerate the epidermis if the skin is wounded. The new report proposes that fully aquatic mammals continuously use the epidermal regeneration program and therefore require only one of the two sets of epidermal keratins.

"It is surprising that the main proteins of the outermost skin layers of terrestrial mammals, including humans, are dispensable in aquatic mammals, such as dolphins, whales, and manatees," said Eckhart. "And it is remarkable that a stress response program was the starting point of an evolutionary innovation: the new architecture of the epidermis in aquatic mammals."

The epidermis of dolphins is approximately 50 times thicker than normal human epidermis. Keratins K1, K2, and K10 have been lost and replaced by keratins K6 and K17 in dolphins.

Both the thickening of the epidermis and the key roles of K6 and K17 are also found in human skin wound healing and in lesional skin of patients with psoriasis. In this common skin disease, so-far-unknown genetic factors predispose skin cells to trigger the evolutionarily ancient wound healing program of the epidermis.

"At this point evolutionary biology meets dermatological research, and we hope that this type of 'translational research' will yield further insights for the benefit of patients in the future," said Eckhart.

The research team at the Medical University of Vienna also discovered previously underestimated complexity in the epidermal keratin composition due to so-called "alternative splicing" keratin K10 mRNA and adaptations of keratin gene sets in terrestrial mammals. However, an entire remodeling of the keratin cytoskeleton has occurred only in fully aquatic mammals.

"Our data point to a general pattern of skin evolution: proteins of innermost skin layers are the most conserved, and proteins of the outermost layers are the most diverse," said Eckhart. "The interactions between keratins and other epidermal proteins need further studies. With progress in comparative genomics and new lines of experimental research, the evolution of the skin will remain an exciting and fruitful research topic."

About 3 million people in the US are diagnosed every year with bipolar disorder, a psychiatric condition characterized by dramatic shifts in mood from depression to mania. Currently, the standard treatment includes a combination of psychotherapy and prescription medications such as mood stabilizers and antipsychotics.

However, an emerging field of research is exploring the use of probiotics--often thought of as "good bacteria"--as a potential new avenue for treatment of bipolar and other psychiatric mood disorders. And a new study from Baltimore's Sheppard Pratt Health System, conducted by a research team led by Faith Dickerson, finds that a probiotic supplement may reduce inflammation of the gut, which is known to exacerbate bipolar disorder. Probiotic organisms are non-pathogenic bacteria that, when present in the gut flora, are known to improve the overall health of the host.

In recent years, research has demonstrated a strong link between the gastrointestinal tract and the central nervous system. This connection, named the "gut-brain axis" (GBA), allows for crosstalk between the endocrine, immune, and autonomic nervous systems. The GI tract is also home to the intestinal microbiome, a complex population of roughly 100 trillion microorganisms (more than ten times the number of cells that make up the human body) that interacts with the mucosal lining of the GI tract. Studies have shown that the intimate association between the gut microbiome and GI tissue has a significant effect on the GBA.

There is also mounting evidence linking imbalances in the microbial species that make up the gut microbiome to a number of health problems including allergies, autoimmune disorders, and psychiatric mood disorders.

In the case of bipolar disorder and the GBA, previous studies have shown that inflammation, or overstimulation of the body's immune system, is a contributing factor in the disease. With this in mind, researchers developed a probiotic supplement aimed at reducing inflammation caused by microbial imbalances in the gut.

A group of patients recently hospitalized for mania participated in a 6-month study to track the effects of probiotic treatment on both their mood and the status of their immune system.

The patients were randomly selected to receive either the probiotic supplement or a placebo in addition to their usual medications. The results showed that the group receiving the probiotic supplement, on average, didn't return to the hospital as quickly and required less in-patient treatment time compared to the placebo group. The beneficial effects were most pronounced in those patients who exhibited abnormally high levels of inflammation at the beginning of the study.

Overall, these results indicate that changes in intestinal inflammation can alter the trajectory of psychiatric mood disorders and that modulating the intestinal microbiota may be a new avenue of treatment for patients suffering from these diseases.

URBANA, Ill. - When humans experience stress, their inner turmoil may not be apparent to an outside observer. But many animals deal with stressful circumstances - overcrowded conditions, not enough food - by completely remodeling their bodies. These stress-induced forms, whether they offer a protective covering or more camouflaged coloration, can better withstand the challenge and help the animal survive until conditions improve.

Until now, it wasn't clear what molecular trigger was pulled to allow this structural remodeling in times of stress. But researchers at the University of Illinois and the University of Pennsylvania have discovered the protein responsible in the roundworm C. elegans.

"We're using a really simple animal system to understand basic biological questions that have implications not only for nematodes, including important crop parasites, but also for higher animals, including humans," says Nathan Schroeder, assistant professor in the Department of Crop Sciences at U of I, and author of the new study published in Genetics.

When C. elegans larvae are stressed, they stop eating, their development halts, and they enter a stress-resistant stage known as dauer. In this form, their bodies become distinctly thinner and longer and develop an outer cuticle with ridges from tip to tail.

Schroeder and his team were investigating a protein called DEX-1 for an unrelated project when they noticed worms without the protein were "dumpy" in the dauer phase: they remained relatively short and round. Intrigued, the researchers decided to characterize the protein and its function in seam cells, the cells responsible for dauer remodeling.

"When we disrupted the DEX-1 protein, the seam cells did not remodel during dauer," Schroeder says. "Seam cells have stem cell-like properties. We usually think about stem cells as controlling cell division, but we found that these cells are actually regulating their own shape through this protein, and that has an impact on overall body shape in response to stress."

DEX-1 is an example of an extracellular matrix protein, a type that is extruded to form the mortar between cells. These proteins exist in every multicellular organism, not only keeping cells together but also facilitating interaction between cells. Not always in a good way; it turns out many extracellular matrix proteins, including a DEX-1 analogue, are associated with human diseases, such as metastatic breast cancer.

Schroeder says his group is interested in looking more closely at metastasis in cancers due to these proteins, but as a nematologist, he gets more excited about the prospect of understanding the basic biology and genetics of nematodes themselves, particularly parasitic species that affect crops.

"For many parasitic nematodes, when they're ready to enter the infective stage, they have a similar process. Many of the genes regulating the decision to go into or come out of that infective stage also regulate the decision to enter dauer," he says. "This research gives us insight into their biology and how they make these developmental decisions."

When young children experience violence or poverty, the effect can last well into adulthood. But new research from the Emory School of Medicine suggests that a strong parental relationship could override some of these effects, by changing how children perceive the environmental cues that help them distinguish between what's safe or dangerous.

To study the impact of the caregiver relationship, a research team led by Jennifer Stevens and Tanja Jovanovic used functional magnetic resonance imaging (fMRI) to observe activity in the amygdala, a key area of the brain that processes fear and emotion. The researchers showed children aged 8-13 a series of photos of adult faces that were either neutral or expressing fear. The amygdalae of children who had experienced violence in their lives grew more active in response to both types of faces, which suggests that these children may engage emotional, fight-or-flight responses even for social cues that are not particularly threatening. This may be an adaptive response to growing up in an unpredictable or dangerous environment. In children who hadn't experienced violence, amygdalae were more only active in response to the fearful faces.

In another part of the experiment, the researchers had children and their mothers collaborate on a challenging Etch-a-Sketch task and rated the mothers' expressions during the interaction. Then they had the children look at photos of faces. When the mothers had been more positive towards their children, the amygdalae of the younger children, aged 8-10, showed a decrease over time in response to the fearful faces . This suggests that in young children, the relationship with a mother affects the brain's response to potential environmental threats. The same effect wasn't observed in older children.

The findings build on earlier research by the same team, which established that the physical distance between young children and their mothers can influence how the children assess danger. In the previous study, young children who were physically nearer to their mothers were better able to differentiate between safe and threatening stimuli. Once again, older children didn't show the same effect.

The findings indicate that even if a child grows up in a stressful environment, parental relationships can protect them, says Stevens. "Interventions such as parent training designed to help parents respond positively to young children, might be especially important in situations that are really challenging or where there are low resources," she says.