Tech

For the first time, a soft and stretchable organic thermoelectric module has been created that can harvest energy from body heat. The breakthrough was enabled by a new composite material that may have widespread use in smart clothing, wearable electronics and electronic skin.

Researchers at the Laboratory of Organic Electronics at Linköping University have developed an organic composite material with unique properties - not only is it soft and stretchable, it also has a high electrical conductivity and good thermoelectric properties. This makes it ideal for many wearable applications.

The researchers have published the result in Nature Communications, together with colleagues from Belgium, New Zealand and California.

Nara Kim, postdoc and principal research engineer in the Laboratory of Organic Electronics, has combined three materials: the conducting polymer PEDOT:PSS, a water-soluble polyurethane rubber, and an ionic liquid. The result is a composite with unique properties. The PEDOT:PSS gives it thermoelectric properties, the rubber provides elasticity, and the ionic liquid ensures softness.

Nara Kim has carried out the research under the leadership of Professor Xavier Crispin and Senior Lecturer Klas Tybrandt, both at the Laboratory of Organic Electronics.

"Xavier Crispin is a pioneer in organic thermoelectric materials; Klas Tybrandt is an expert in soft electronic materials; and I contribute my knowledge of organic composites. We came up with the idea for the new material together", she says.

PEDOT:PSS is the most common conducting polymer and is used in many applications, not least due to its good thermoelectric properties. But thick polymer film is too hard and brittle to be successfully integrated into wearable electronics.

"Our material is 100 times softer and 100 times more stretchable than PEDOT:PSS", says Klas Tybrandt, who leads the group of Soft Electronics at the Laboratory of Organic Electronics.

"The ability to control the structure of the material both at the nanoscale and the microscale allows us to combine the excellent properties of the different materials in a composite", he says.

The new composite is also printable.

"The composite was formulated by water-based solution blending and it can be printed onto various surfaces. When the surface flexes or folds, the composite follows the motion. And the process to manufacture the composite is cheap and environmentally friendly", says Nara Kim.

The researchers see a huge range of new possibilities using the material to create soft and elastic organic conducting materials.

"There are many ionic liquids, conducting polymers and traditional elastomers that can be combined to give new nanocomposites for many applications, such as thermoelectric generators, supercapacitors, batteries, sensors, and in wearable and implantable applications that require thick, elastic and electrically conducting materials", says Xavier Crispin.

Certain forms of epilepsy are accompanied by inflammation of important brain regions. Researchers at the University of Bonn have now identified a mechanism that explains this link. Their results may also pave the way to new therapeutic options in the medium term. They have now been published in the renowned scientific journal "Annals of Neurology".

Epilepsy can be hereditary. In other cases, patients only develop the disease later in life: as a result of a brain injury, after a stroke or triggered by a tumor. Inflammation of the meninges or the brain itself can also result in epilepsy.

Particularly dangerous are inflammatory reactions affecting the so-called hippocampus, which is a brain structure that plays an important role in memory processes and the development of emotions. Doctors call this condition limbic encephalitis. "However, in many cases it is still not clear what causes such inflammation," explains Prof. Dr. Albert Becker, who heads the Section for Translational Epilepsy Research at the University Hospital Bonn.

Researchers have now identified an autoantibody that is believed to be responsible for encephalitis in some patients. Unlike normal antibodies, it is not directed against molecules that have entered the organism from outside, but against the body's own structures - hence the prefix "auto", which can be translated as "self". The researchers discovered it in the spinal fluid of epilepsy patients suffering from acute inflammation of the hippocampus. The autoantibody is directed against the protein Drebrin. Drebrin ensures that the contact points between nerve cells function correctly. At these so-called synapses, the neurons are interconnected and pass on their information.

When the autoantibody encounters a Drebrin molecule, it knocks it out of action and thereby disrupts the transmission of information between nerve cells. At the same time it alerts the immune system, which is then activated and switches to an inflammatory mode, while simultaneously producing even more autoantibodies. "However, Drebrin is located inside the synapses, whereas the autoantibody is located in the tissue fluid," says Dr. Julika Pitsch, who heads a junior research group in Prof. Becker's department. "These two should therefore normally never come into contact with each other." The autoantibody seems to use a back door to enter the cell. This is actually intended for completely different molecules: the so-called neurotransmitters.

Into the nerve cell by Trojan horse

Information processing in the brain is electrical. The synapses themselves however communicate via chemical messengers, the aforementioned neurotransmitters: In response to an electrical pulse, the transmitter synapse emits transmitters that then dock to certain receptors of the receiver synapse, where they in turn also generate electrical pulses.

The synaptic vesicles - the packaging of the neurotransmitters - are absorbed again and recycled. "The autoantibody seems to use this route to sneak into the cell, as with a Trojan horse," explains Becker's colleague Prof. Dr. Susanne Schoch McGovern.

In cell culture experiments, the researchers were able to show what happens next: Shortly after the addition of the autoantibody, the neurons in the Petri dish begin to fire machine gun-like rapid bursts of electrical impulses. "We know that this form of electrical excitation is contagious, so to speak," emphasizes Prof. Becker. "With nerve cells, which are interconnected to form a network, all the nerve cells involved suddenly start firing wildly." This may then result in an epileptic seizure.

The results also give hope for new therapeutic approaches. For instance, active substances such as cortisone can suppress the immune system and thereby possibly also prevent the massive production of autoantibodies. It may also be possible to intercept and incapacitate them specifically with certain drugs. But there is still a long way to go before treatment becomes available, stresses Prof. Dr. Rainer Surges, Director of the Department of Epileptology at the University Hospital Bonn. Moreover, it would primarily benefit patients with this particular form of the disease. For them, however, the benefit would probably be huge: In contrast to congenital epilepsies, those based on inflammation may possibly be cured in the future with the appropriate therapy.

China's fast economic growth and accompanying rise in food demand is driving an increase in water use for agriculture and industry, thus threatening the country's water security. The findings of a new study underscore the value and potential of technological adoptions to help design targets and incentives for water scarcity mitigation measures.

Over the last century, people's water use has been increasing at more than twice the rate of the global population itself, with around 77% of this growth taking place in developing countries. According to the authors of the study published in the Proceedings of the National Academy of Sciences (PNAS), a lack of spatially detailed datasets however limits our understanding of historical water use trends and its key drivers, which makes future projections unreliable. As there are currently very few observation-based studies aimed at understanding the dynamics of historical water use, the authors endeavored to provide a detailed picture of how water use has been evolving amid socioeconomic, technological, and policy impacts, specifically in China. They provide evidence of the deceleration of human water use in the country and also attempted to identify the importance of water-conserving technological adoptions.

"The key question we wanted to address was how human water use responds to socioeconomic development, climate change, and policy interventions over time and space. We looked at China, not only because the country has transitioned from an underdeveloped country to the second largest economy in the world, but also because it is home to some of the Earth's most water-stressed regions. Diverse water conservancy measures were developed since the 1980s to avoid a long term water crisis, but it is not well known how water use is influenced by economic growth, structural transitions, and policy interventions," explains study lead author Feng Zhou, an Associate Professor at Peking University in China.

The researchers found that although China's water use doubled between 1965 and 2013, there was a widespread slowdown in the growth rates from 10.66 km3 per year before 1975, to 6.23 km3 per year in 1975 to 1992, and further down to 3.59 km3 per year in the following years. These decelerations were attributed to reduced water-use in irrigation and industry, which partly offset the increase driven by pronounced socioeconomic growth. The adoption of highly efficient irrigation techniques such as drip or sprinkler irrigation systems and industrial water recycling technologies explained most of the observed reduction of water-use intensities across China. Without these technologies, China's freshwater withdrawals would have been 80% more than the actual water use over the last two decades.

While water-conserving technological adoptions can deliver benefits of decoupling water use from socioeconomic development, studies in other countries have revealed an opposite relationship where technological adoption has led to an increase in intensive farming and thereby an increase in water use. According to the study, the first reason for these inconsistent results could be that intensive farming, such as high planting density and more sequential cropping had already been well developed in many Chinese prefectures. The second reason may lie in the nature of land institution in China where additional intensification requiring a change in irrigation infrastructure has been difficult to adopt due to the high fixed costs of the small fields allocated to farmers.

The authors explain that in China, the technological adoptions were accompanied by policy interventions including about 40 laws, regulations, programs, and action plans. In addition, the growth of China's water use is very likely to continue to slow down, as the latest policy interventions provide a more stringent constraint to approach a peak of water withdrawal. However, uncertainties and potential future water scarcity will come from three aspects:

First, China's land institution is undergoing a rapid transition towards large-scale farming through the farmland transfer system issued in 2014 alongside the adoption of water-conserving irrigation planned to cover 75% of the irrigated area in 2030. These ongoing transitions may lead farmers to expand irrigated areas or shift to water-intensive crops, which could offset the savings due to future improvement of irrigation efficiency.

The results further indicate that the westward development of the industrial sector has worsened water scarcity in many arid and semi-arid regions. High industrial water recycling has already been adopted in almost all these regions (>88%) except in Xinjiang, so that the potential for further water conservation would be limited. Without a stronger enforcement of capping water withdrawal, the industrial sector may become the most important driver continuing to increase water use.

Lastly, China is urbanizing at an unprecedented rate and the increasing per-capita income, coupled with generalized tap water accessibility, will likely stimulate more water-intensive lifestyles and thereby increase domestic water use.

The deceleration of water use revealed in this study partly challenges the results from global hydrological models, which commonly suggest an increase of total water use across China over the period 1971 to 2010. Zhou points out that one reason for this bias may be that technological change factors were prescribed as constant over space and time without consideration of policy interventions and actual technological adoption. It might however also be that socioeconomic activities data on China were simply disaggregated from national-scale statistics. The authors recommend that to improve model drivers, survey-based reconstruction datasets of water use ? like those presented in this study ? are valuable, and should be extended to other regions. In addition, the linkages between changes in water use and technological adoptions identified may be also be useful in the design of more realistic future water withdrawal scenarios, with the ultimate goal to improve global models used to assess water use targets and water scarcity mitigation.

"Modeling water use is very complex and we need much more regional data and coordination to improve our understanding of people and how they use water. The modeling community should work together to achieve this as it is crucial to identify the key drivers and mechanisms behind changing water use patterns across the world that help make future projections more reliable. Future policies to underpin water targets in for example, the UN Sustainable Development Goals framework, will be key to addressing the challenge of decoupling water use from socioeconomic development in China and other water-stressed countries," concludes study coauthor and IIASA Acting Water Program Director, Yoshihide Wada.

CHAMPAIGN, Ill. -- A bacterial protein fragment instigates lung tissue death in pulmonary fibrosis, a mysterious disease affecting millions of people worldwide, according to a new study from researchers at the University of Illinois at Urbana-Champaign and Mie University in Japan.

Led by Illinois microbiology and animal sciences professor Isaac Cann and Mie University immunology professor Dr. Esteban Gabazza, the researchers published their findings in the journal Nature Communications. Cann and Gabazza are affiliates of the Carl R. Woese Institute for Genomic Biology at Illinois.

"We discovered salt-loving bacteria in the lungs of patients with pulmonary fibrosis, and these bacteria secrete a peptide that marks the lung cells it touches for death," Cann said.

In people with pulmonary fibrosis, lung tissue becomes progressively more scarred and stiffened, with a prognosis of only three to five years of life after diagnosis. Certain environmental factors, infections or medications are linked to disease onset; however, the majority of cases are of unknown origin. These mysterious cases are called idiopathic pulmonary fibrosis. About 50,000 patients in the U.S. die of IPF every year - more than die from breast cancer, according to the IPF Foundation.

The disease progresses slowly until a point when a patient experiences a rapid worsening of breathing and loss of lung function, a phase called acute exacerbation. Yet doctors do not know what triggers acute exacerbation in a stable patient.

"More than half of the patients with IPF die because of acute exacerbation of the disease," Gabazza said. Of those who survive an acute exacerbation event, only 50% live more than four months, he said.

Previous studies found that certain bacteria, such as strains of Halomonas, Staphylococcus and Streptococcus, proliferate in the lungs of IPF patients, likely as a result of high amounts of salt in the lining of patients' lungs. The researchers wondered if the bacteria played a role in acute exacerbation, so they cultured bacteria associated with fibrotic lung tissue in a salty environment and studied what the bacteria secreted.

They found a small peptide, secreted by Staphylococcus nepalensis, that rapidly kills lung cells. They named the peptide corisin.

To confirm that corisin was the exacerbating culprit, Gabazza's group ran an experiment on mice with IPF. They compared mice given corisin itself, those infected with corisin-secreting Staphylococcus nepalensis, those infected with a Staph strain that did not secrete corisin, and an untreated control group. They found that the mice given corisin or the bacterium that secretes it showed much greater signs of acute exacerbation.

They also looked at lung tissue samples from human patients and found that those who had undergone acute exacerbation had higher levels of corisin in their lungs.

Cann's group then searched the genome of Staphylococcus nepalensis to figure out where corisin comes from. They found that it is a fragment cut from a larger protein. They tested the larger protein on lung tissue and found it did not have the destructive properties of the fragment.

"It's like a Trojan horse," Cann said. "Anybody trying to characterize the large protein to find what it does would never know it has this destructive element hidden inside it. The microbe makes the polypeptide and then it cuts out that small piece of it, the corisin, and that is very deadly."

Next, the researchers hope to identify the enzyme that cuts corisin out of its larger protein. They aim to create agents to block it - effectively bolting shut the door of the Trojan horse. They also plan to identify which other strains of bacteria produce corisin or similar peptides, and to study other types of fibrosis, such as in the kidneys and liver, to see if corisin or other bacterial agents play a role in those diseases.

"Knowing that a cause of the acute exacerbation is a bacteria-derived factor gives us a fightable enemy," Gabazza said. "On the patient side, this new discovery could mitigate the psychological stress of fighting against an 'unknown intruder,' while on the physician side, this can stimulate the development of strategies for treatment and drug discovery."

Men are more prone to competitive risk taking and violent behavior, so what happens when the number of men is greater than the number of women in a population?  

According to research by Florida State University Professor of Psychology Jon Maner, the answers might not be what you expect. 

"When men outnumber women in a given ecology, intuition might suggest that rates of violent crime would skyrocket, marriages would destabilize and many children would be born out of wedlock," he said. "Intriguingly, the opposite has been observed." 

Maner's study, "Ecological Sex Ratios and Human Mating," was published in the journal Trends in Cognitive Sciences. The study was based on a review and analysis of previous work on the topic conducted by Maner and others. 

Although ecological sex ratios have been investigated extensively in nonhuman species, they play a crucial role in humans as well. Many factors can produce sex ratio imbalances, including wars, which kill more men than women, and sex-differentiated migration patterns.  

"One of the central ideas is that when there is an imbalance in sex ratios, whichever sex is in the majority faces a lot more competition when it comes to finding and retaining romantic partners," he said. "One way in which that competition expresses itself is in the way both men and women shift their overall mating strategy toward the typical mating strategy of the other gender." 

In order to compete, many male species will often resort to competitive risk taking or violent behaviors to attract females. In human males this means attention-grabbing, riskier behaviors like overextending financially to purchase status symbols, riding motorcycles and fighting.  

But there are other male responses that are lesser known and, Maner pointed out, more typical of females.   

"Another  way men can compete with one another is by being quicker to settle down with one woman, get married and really devote himself more fully to having kids and being a good parent," he said. "On the other hand, if he isn't able to find a partner, he might be inclined to compete in other ways and that's where you might find increased violence, risk taking and competition with other men." 

Maner said his study also revealed this crisscross of traits works in the opposite direction with women adopting behavior more typical of men when they are in the overrepresented population.  

"When women are more abundant, they are more open to casual sexual relationships, less likely to get married," he said. "They are essentially catering to what is often the trait among men, which is to play the field." 

For those in overrepresented populations who might already have trouble finding a mate, competition to win a mate's affections can get especially difficult. Maner mentioned men of low socioeconomic status as an example. 

"They are generally less desirable to potential partners and their mating opportunities are limited," he said. "They face especially fierce competition, so they are especially inclined to find a partner and settle down quickly."  

Despite increasing awareness of how critical sleep is to our health, getting a good night's rest remains increasingly difficult in a world that's always "on" -- responding to emails at all hours, news cycles that change with every tweet and staring endlessly into the blue light of cell phone, tablet and computers screens.

Scientists have stressed the importance of healthy sleep habits, recommending at least seven hours each night, and have linked lack of sleep to an increased risk in numerous health conditions, including diabetes, stroke and cardiovascular disease.

Now a new study shows whether or not you go to bed on time could also have an effect on your health. Researchers at the University of Notre Dame studied the correlation between bedtime regularity and resting heart rate (RHR) and found that individuals going to bed even 30 minutes later than their usual bedtime presented a significantly higher resting heart rate that lasted into the following day.

"We already know an increase in resting heart rate means an increased risk to cardiovascular health," said Nitesh Chawla, the Frank M. Freimann professor of Computer Science and Engineering at Notre Dame, director of the Center for Network and Data Science and a lead author of the study. "Through our study, we found that even if you get seven hours of sleep a night, if you're not going to bed at the same time each night, not only does your resting heart rate increase while you sleep, it carries over into the next day."

Chawla and his team analyzed data collected via Fitbit from 557 college students over the course of four years. They recorded 255,736 sleep sessions -- measuring bedtimes, sleep and resting heart rate. Significant increases in RHR were observed when individuals went to bed anywhere between one and 30 minutes later than their normal bedtime. Normal bedtime was defined as the one-hour interval surrounding a person's median bedtime. The later they went to bed, the higher the increase in RHR. Rates remained elevated into the following day.

Surprisingly, going to bed earlier than one's standard bedtime also showed signs of increasing RHR, though it depended on just how early. Going to bed 30 minutes earlier than usual appeared to have little effect, while going to bed more than a half hour earlier significantly increased RHR. In cases of earlier bedtimes, however, RHR leveled out during the sleep session. Circadian rhythms, medications and lifestyle factors all come into play when it comes to healthy sleep habits, but Chawla said it's vital to consider consistency as well.

"For some, it may be a matter of maintaining their regular 'work week' bedtime through the weekend," said Chawla. "For shift workers and those who travel frequently, getting to bed at the same time each night is a challenge. Establishing a healthy bedtime routine -- as best you can -- is obviously step number one. But sticking to it is just as important."

ITHACA, N.Y. - People who tend to recognize similarities between people they know and people depicted in the media are more likely to believe common myths about sexual assault, according to a new study co-led by a Cornell researcher.

The data, culled from more than 280 interviews with students at eight community colleges in the southeastern United States, suggests that media literacy education could help raise awareness about sexual violence, and improve sexual violence prevention programs on college campuses.

"There is work establishing connections between media that people consume and their beliefs about rape, but less is known about how people make sense of those media messages," said Kristen Elmore, assistant director of the Program for Research on Youth Development and Engagement in the College of Human Ecology's Bronfenbrenner Center for Translational Research. "And what we found is that there's a positive relationship between 'seeing other people I know in media,' and beliefs that endorse the myths that women who are raped are 'asking for it,' or that men never really intended to do it."

Elmore is first author of "Rape Myth Acceptance Reflects Perceptions of Media Portrayals as Similar to Others, But Not the Self," which published March 23 in the journal Violence Against Women. It was co-authored with researchers at Innovation Research and Training, an independent social sciences research firm in Durham, North Carolina, who conducted the survey in 2015.

"In that dataset was an opportunity to explore these questions about beliefs in rape myths and how they might be related to representations of rape in the media," Elmore said. "It helps us try to answer a question that many of us have been thinking about since the #MeToo movement began, which is: Where do these myths about rape come from?"

The researchers asked participants to rate their agreement with 13 statements associated with rape. They then asked them whether people portrayed in various types of media, including music, movies and television, were similar to them, similar to people they knew, or realistic portrayals, and whether they aspired to be like the people depicted in media. The survey also asked about religious background and past experience with dating violence.

They found men were more likely than women to believe three rape myths - that women who are raped were "asking for it"; that men "didn't mean to rape" but couldn't help themselves; and that "it wasn't really rape" unless it was by a stranger. For two of the three rape myths, they found that both men and women were more likely to believe them if they reported seeing similarities between people they knew and people they saw in the media.

The fact that there was no correlation between belief in rape myths and seeing themselves in media could reflect what's known as "optimism bias," Elmore said - people's belief that good things are more likely to happen to them and bad things are more likely to happen to others.

Elmore said that although the study doesn't show that perceptions of the media cause belief in rape myths, it suggests that depictions of rape in media could shape people's views.

"If I know something about how people interpret media," Elmore said, "I can at least predict something about their beliefs about rape, though there may be some third variable influencing both of those things."

Because the survey was conducted before most of the recent revelations arising from the #MeToo movement, future work will assess whether portrayals of sexual violence in the media - as well as people's perceptions of rape myths - have changed for the better, Elmore said.

"We're at this interesting time where media narratives about sexual assault may be changing in really important ways," she said, "and there seems to be more space for discussion that challenges common rape myths."

HOUSTON - (March 24, 2020) - Barack Obama's election to the nation's highest office in 2008 improved the mental health of black men, according to new research from Rice University.

"'Yes We Can!' The Mental Health Significance for U.S. Black Adults of Barack Obama's 2008 Presidential Election" is available online and will appear in an upcoming volume of the journal Sociology of Race and Ethnicity.

Lead researcher Tony Brown, a professor of sociology at Rice, said sociologists typically focus on how negative events such as disasters, job losses, interpersonal discrimination, food insecurity and poverty impact people's lives and health. What they don't often think about is how positive events impact people.

"This is one major reason we pursued this study -- we wanted to know if there were any health implications from this momentous occasion in U.S. history," he said.

Brown and his co-authors examined black adults' mental health for 30 days prior to and 30 days following the 2008 election. The data came from the Behavioral Risk Factor Surveillance System, a nationally representative survey of 400,000 U.S. adults evaluating different health aspects. The researchers found the election resulted in a statistically significant mental health benefit for black men.

One survey question asked, "Now thinking about your mental health, which includes stress, depression and problems with emotions, for how many days during the past 30 days was your mental health not good?" On average, black men said they experienced about four poor mental health days leading up to the election. Following the election, that number dropped to three.

To demonstrate the significance of this finding, Brown referenced another study examining mental health harm caused when black adults were exposed to nearby police shootings of unarmed blacks. That study's survey participants reported a 0.14-day increase in mental health problems.

"The study's findings are important because we do not fully understand what factors protect mental health," Brown said. "Specifically, the findings demonstrate that sociopolitical shifts matter for the health of black men and that everyday conditions of life act as social determinants of health."

However, black women did not experience the same mental health benefit from the 2008 election as black men. During the 30 days before the election, black women reported, on average, 4.6 poor mental health days. Following the election, that went up to five days. While Brown could not pinpoint a specific reason for this slight mental health decline, he theorizes that there could be a few possible explanations.

"Black women could have faced an internal conflict over not being able to vote for Hillary Clinton, a woman," Brown said. "They could also have been concerned over the uptick in death threats just 10 days following Obama's election, worrying about the new president-elect in the same way they would worry about their own husbands, fathers or sons. They might also have been concerned over how President Obama would deal with discrimination against black men versus black women." Finally, Brown said black women may have worried that Obama's election would result in a backlash in years to come, resulting in the country moving back toward a racist "status quo."

As the 2020 presidential election approaches, Brown said health researchers should take shifts in the sociopolitical climate into account.

"Groups of voters are symbolically empowered or disempowered by the biography, blind spots and biases of those wining presidential elections," he said.

Brown and his co-authors are interested in future work on the mental health impact of other election results, including the effect of Donald Trump's 2016 presidential election on white women.

Belying their slimy natures, the sticky patches of bacteria called biofilms often form intricate, starburst-like patterns as they grow. Now, researchers at Princeton University have combined expertise in molecular biology, mechanical engineering and mathematical modeling to unravel the physical processes underlying these curious crinkles.

"At a certain point, patterns appear: stripes, zigzags and rings," said co-author Ned Wingreen, the Howard A. Prior Professor in the Life Sciences and a professor of molecular biology and the Lewis-Sigler Institute for Integrative Genomics. "It's been one of those things that has personally always puzzled me."

The study, published Mar. 19 in the Proceedings of the National Academy of Sciences, helps illuminate how bacteria grow in diverse environments, and could also aid investigations into the physical forces that govern growth and morphing of human tissues.

"This adds to a body of work coming from a mechanical perspective that says what we're seeing is the playing out of physical laws," said Wingreen. "It will help us understand to what extent some of these patterns influence the biofilm properties that are important biologically and medically."

The work is the latest to stem from a collaboration among four faculty members investigating biofilms from multiple perspectives. Along with Wingreen, the team includes Andrej Košmrlj, an assistant professor of mechanical and aerospace engineering; Howard Stone, the Donald R. Dixon '69 and Elizabeth W. Dixon Professor of Mechanical and Aerospace Engineering; and Bonnie Bassler, the Squibb Professor in Molecular Biology. They previously worked together to develop a method for peeling biofilms off surfaces.

In this study, the researchers analyzed biofilm formation of the bacterium Vibrio cholerae, which is widespread in watery environments and can cause the disease cholera when ingested by humans. On a soft substrate, the biofilms initially grow as a flat layer but later become wrinkled, with radial and zigzag patterns of peaks and valleys. The study showed that these patterns depend on the relative softness or stiffness of the biofilm's substrate, which the researchers manipulated by varying the concentration of agar, a seaweed-derived substance commonly used to fill Petri dishes.

On a stiffer substrate, wrinkles first appear at a biofilm's center and propagate outward, while on a softer substrate wrinkles begin to form at the edges and propagate toward the center. In both cases, biofilms end up with zigzag wrinkle patterns at their centers and a more ordered pattern of radial stripes at their outer edges.

This process is driven by a nexus of influences, including each bacterium's uptake of nutrients from the substrate, which leads to uneven growth as nutrients are depleted in the biofilm's center. The bacteria produce new extracellular matrix components as they grow and they also produce molecules that make the bacteria stick to each other and to the substrate.

"This is a very complicated process involving growth and mechanics," said lead author Chenyi Fei, a graduate student in the Lewis-Sigler Institute. "To understand it, we built what we call a chemo-mechanical model. We take into account the nutrients and the nonuniform growth of the biofilm, and how those features translate into the mechanical forces or stresses that accumulate."

The model allowed the researchers to predict which regions of the biofilm would experience maximum stress at particular points in time, and thus to predict where wrinkles would form. The predictions corresponded well with experimental measurements of three-dimensional shapes of actual biofilms, said Fei, whose graduate work is co-advised by Wingreen and Bassler.

"Chenyi cleverly integrated a lot of different mechanisms that are normally studied separately," said Košmrlj.

A key aspect of the model is its adoption of classic engineering analyses of mechanical instabilities, which have previously been applied to such problems as the buckling of railroad tracks in extreme temperatures. A similar type of instability causes soft materials like biofilms to form wrinkles.

"In the previous century, mechanical instabilities were being studied with a focus on trying to prevent failure mechanisms in structures," said co-author Sheng Mao, a former postdoctoral researcher at Princeton who is now an assistant professor at Peking University. "But in a new wave of studies, we are trying to exploit these mechanical instabilities to make tunable structures for various purposes," such as soft materials being developed to treat injuries and diseases through tissue engineering.

In addition to advancing knowledge of how growing cells interact with soft substrates, the researchers plan to build on their findings to further investigate bacterial life cycles, including the dispersal stage in which some bacterial cells detach from a biofilm, exit the structure, and colonize new areas.

Bacteria such as V. cholerae "are opportunists," said Wingreen. "They come in, grab some territory, expand, eat everything they can, and then leave. But this last aspect, dispersal, is understudied, and the physics and mechanics of dispersal are going to offer some interesting challenges."

Scientists are preparing a massive computer model of the coronavirus that they expect will give insight into how it infects in the body. They've taken the first steps, testing the first parts of the model and optimizing code on the Frontera supercomputer at the University of Texas at Austin's Texas Advanced Computing Center (TACC). The knowledge gained from the full model can help researchers design new drugs and vaccines to combat the coronavirus.

Rommie Amaro is leading efforts to build the first complete all-atom model of the SARS-COV-2 coronavirus envelope, its exterior component. "If we have a good model for what the outside of the particle looks like and how it behaves, we're going to get a good view of the different components that are involved in molecular recognition." Molecular recognition involves how the virus interacts with the angiotensin converting enzyme 2 (ACE2) receptors and possibly other targets within the host cell membrane. Amaro is a professor of chemistry and biochemistry at the University of California, San Diego.

The coronavirus model is anticipated by Amaro to contain roughly 200 million atoms, a daunting undertaking, as the interaction of each atom with one another has to be computed. Her team's workflow takes a hybrid, or integrative modeling approach.

"We're trying to combine data at different resolutions into one cohesive model that can be simulated on leadership-class facilities like Frontera," Amaro said. "We basically start with the individual components, where their structures have been resolved at atomic or near atomic resolution. We carefully get each of these components up and running and into a state where they are stable. Then we can introduce them into the bigger envelope simulations with neighboring molecules."

On March 12-13, 2020, the Amaro Lab ran molecular dynamics simulations on up to 4,000 nodes, or about 250,000 processing cores, on Frontera. Frontera, the #5 top supercomputer in the world and #1 academic supercomputer according to November 2019 rankings of the Top500 organization, is the leadership-class high performance computing system supported by the National Science Foundation.

"Simulations of that size are only possible to run on a machine like Frontera or on a machine possibly at the Department of Energy," Amaro said. "We straightaway contacted the Frontera team, and they've been very gracious in giving us priority status for benchmarking and trying to optimize the code so that these simulations can run as efficiently as possible, once the system is actually up and running."

"It's exciting to work on one of these brand new machines, for sure. Our experience so far has been very good. The initial benchmarks have been really impressive for this system. We're going to continue to optimize the codes for these ultra large systems so that we can ultimately get even better performance. I would say that working with the team at Frontera has also been fantastic. They're at the ready to help and have been extremely responsive during this critical time window. It's been a very positive experience," Amaro said.

"TACC is proud to support this critical and groundbreaking research," said Dan Stanzione, Executive Director of TACC and Principal Investigator of the Frontera supercomputer project. "We will continue to support Amaro's simulations and other important work related to understanding and finding a way to defeat this new threat."

Amaro's work with the coronavirus builds on her success with an all-atom simulation of the influenza virus envelope, published in ACS Central Science, February 2020. She said that the influenza work will have a remarkable number of similarities to what they're now pursuing with the coronavirus.

"It's a brilliant test of our methods and our abilities to adapt to new data and to get this up and running right off the fly," Amaro said. "It took us a year or more to build the influenza viral envelope and get it up and running on the national supercomputers. For influenza, we used the Blue Waters supercomputer, which was in some ways the predecessor to Frontera. The work, however, with the coronavirus obviously is proceeding at a much, much faster pace. This is enabled, in part because of the work that we did on Blue Waters earlier."

Said Amaro: "These simulations will give us new insights into the different parts of the coronavirus that are required for infectivity. And why we care about that is because if we can understand these different features, scientists have a better chance to design new drugs; to understand how current drugs work and potential drug combinations work. The information that we get from these simulations is multifaceted and multidimensional and will be of use for scientists on the front lines immediately and also in the longer term. Hopefully the public will understand that there's many different components and facets of science to push forward to understand this virus. These simulations on Frontera are just one of those components, but hopefully an important and a gainful one."

Fears that electric cars could actually increase carbon emissions are unfounded in almost all parts of the world, new research shows.

Media reports have regularly questioned whether electric cars are really "greener" once emissions from production and generating their electricity are taken into account.

But a new study by the universities of Exeter, Nijmegen and Cambridge has concluded that electric cars lead to lower carbon emissions overall, even if electricity generation still involves substantial amounts of fossil fuel.

Already under current conditions, driving an electric car is better for the climate than conventional petrol cars in 95% of the world, the study finds.

The only exceptions are places like Poland, where electricity generation is still mostly based on coal.

Average lifetime emissions from electric cars are up to 70% lower than petrol cars in countries like Sweden and France (which get most of their electricity from renewables and nuclear), and around 30% lower in the UK.

In a few years, even inefficient electric cars will be less emission-intensive than most new petrol cars in most countries, as electricity generation is expected to be less carbon-intensive than today.

The study projects that in 2050, every second car on the streets could be electric. This would reduce global CO2 emissions by up to 1.5 gigatons per year, which is equivalent to the total current CO2 emissions of Russia.

The study also looked at electric household heat pumps, and found they too produce lower emissions than fossil-fuel alternatives in 95% of the world.

Heat pumps could reduce global CO2 emissions in 2050 by up to 0.8 gigatons per year - roughly equal to Germany's current annual emissions.

"We started this work a few years ago, and policy-makers in the UK and abroad have shown a lot of interest in the results," said Dr Jean-Francois Mercure, of the Global Systems Institute at the University of Exeter.

"The answer is clear: to reduce carbon emissions, we should choose electric cars and household heat pumps over fossil-fuel alternatives."

"In other words, the idea that electric vehicles or electric heat pumps could increase emissions is essentially a myth," said Dr Florian Knobloch, of the Environmental Science Department at the University of Nijmegen (The Netherlands), the lead author of the study.

"We've seen a lot of discussion about this recently, with lots of disinformation going around.

"Here is a definitive study that can dispel those myths. We have run the numbers for all around the world, looking at a whole range of cars and heating systems.

"Even in our worst-case scenario, there would be a reduction in emissions in almost all cases. This insight should be very useful for policy-makers."

The study examined the current and future emissions of different types of vehicles and home heating options worldwide.

It divided the world into 59 regions to account for differences in power generation and technology.

In 53 of these regions - including all of Europe, the US and China - the findings show electric cars and heat pumps are already less emission-intensive than fossil-fuel alternatives.

These 53 regions represent 95% of global transport and heating demand and, with energy production decarbonising worldwide, Dr Mercure said the "last few debatable cases will soon disappear".

The researchers carried out a life-cycle assessment in which they not only calculated greenhouse gas emissions generated when using cars and heating systems, but also in the production chain and waste processing.

"Taking into account emissions from manufacturing and ongoing energy use, it's clear that we should encourage the switch to electric cars and household heat pumps without any regrets," Dr Knobloch concluded.

A quantum internet could be used to send unhackable messages, improve the accuracy of GPS, and enable cloud-based quantum computing. For more than twenty years, dreams of creating such a quantum network have remained out of reach in large part because of the difficulty to send quantum signals across large distances without loss.

Now, Harvard and MIT researchers have found a way to correct for signal loss with a prototype quantum node that can catch, store and entangle bits of quantum information. The research is the missing link towards a practical quantum internet and a major step forward in the development of long-distance quantum networks.

"This demonstration is a conceptual breakthrough that could extend the longest possible range of quantum networks and potentially enable many new applications in a manner that is impossible with any existing technologies," said Mikhail Lukin, the George Vasmer Leverett Professor of Physics and a co-Director of Harvard Quantum Initiative. "This is the realization of a goal that has been pursued by our quantum science and engineering community for more than two decades."

The research is published in Nature.

Every form of communication technology-- from the first telegraph to today's fiber optic internet -- has had to address the fact that signals degrade and are lost when transmitted over distances. The first repeaters, which receive and amplify signals to correct for this loss, were developed to amplify fading wire telegraph signals in the mid-1800s. Two hundred years later, repeaters are an integral part of our long-distance communications infrastructure.

In a classical network, if Alice in New York wants to send Bob in California a message, the message travels from coast to coast in more or less a straight line. Along the way, the signal passes through repeaters, where it is read, amplified and corrected for errors. The whole process is at any point vulnerable to attacks.

If Alice wants to send a quantum message, however, the process is different. Quantum networks use quantum particles of light - individual photons - to communicate quantum states of light over long distances. These networks have a trick that classical systems don't: entanglement.

Entanglement -- what Einstein called "spooky action at a distance" -- allows bits of information to be perfectly correlated across any distance. Because quantum systems can't be observed without changing, Alice could use entanglement to message Bob without any fear of eavesdroppers. This notion is the foundation for applications such quantum cryptography -- security that is guaranteed by the laws of quantum physics.

Quantum communication over long distances, however, is also affected by conventional photon losses, which is one of the major obstacles for realizing large-scale quantum internet. But, the same physical principle that makes quantum communication ultra-secure also makes it impossible to use existing, classical repeaters to fix information loss.

How can you amplify and correct a signal if you can't read it? The solution to this seemingly impossible task involves a so-called quantum repeater. Unlike classical repeaters, which amplify a signal through an existing network, quantum repeaters create a network of entangled particles through which a message can be transmitted.

In essence, a quantum repeater is a small, special-purpose quantum computer. At each stage of such a network, quantum repeaters must be able to catch and process quantum bits of quantum information to correct errors and store them long enough for the rest of the network to be ready. Until now, that has been impossible for two reasons: First, single photons are very difficult to catch. Second, quantum information is notoriously fragile, making it very challenging to process and store for long periods of time.

Lukin's lab, in collaboration with Marko Loncar, the Tiantsai Lin Professor of Electrical Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS),

Hongkun Park, Mark Hyman Jr. Professor of Chemistry at the Harvard Faculty of Arts and Sciences (FAS), and Dirk Englund, Associate Professor of Electrical Engineering and Computer Science at Massachusetts Institute of Technology (MIT), has been working to harness a system that can perform both of these tasks well -- silicon-vacancy color centers in diamonds.

These centers are tiny defects in a diamond's atomic structure that can absorb and radiate light, giving rise to a diamond's brilliant colors.

"Over the past several years, our labs have been working to understand and control individual silicon-vacancy color centers, particularly around how to use them as quantum memory devices for single photons," said Mihir Bhaskar, a graduate student in the Lukin group.

The researchers integrated an individual color-center into a nanofabricated diamond cavity, which confines the information-bearing photons and forces them to interact with the single color-center. They then placed the device in a dilution refrigerator, which reaches temperatures close to absolute zero, and sent individual photons through fiber optic cables into the refrigerator, where they were efficiently caught and trapped by the color-center.

The device can store the quantum information for milliseconds -- long enough for information to be transported over thousands of kilometers. Electrodes embedded around the cavity were used to deliver control signals to process and preserve the information stored in the memory.

"This device combines the three most important elements of a quantum repeater -- a long memory, the ability to efficiently catch information off photons, and a way to process it locally," said Bart Machielse, a graduate student in the Laboratory for Nanoscale Optics. "Each of those challenges have been addressed separately but no one device has combined all three."

"Currently, we are working to extend this research by deploying our quantum memories in real, urban fiber-optic links," said Ralf Riedinger, a postdoctoral candidate in the Lukin group. "We plan to create large networks of entangled quantum memories and explore the first applications of the quantum internet."

"This is the first system-level demonstration, combining major advances in nanofabrication, photonics and quantum control, that shows clear quantum advantage to communicating information using quantum repeater nodes. We look forward to starting to explore new, unique applications using these techniques," said Lukin.

Around four in a thousand people worldwide suffer from schizophrenia, according to scientific estimates. The disease affects people from all walks of life, including Vincent van Gogh, the painter Agnes Martin, mathematician John Nash and Eduard Einstein, a son of the great physicist. The disease touches men and women equally.

Despite its prevalence, however, schizophrenia has remained a mystery. Diagnosis has relied on patient behavior, such as hallucinations, delusions and disordered thinking, rather than on quantitative biomarkers. As a result, psychiatrists' ability to objectively diagnose and treat people with the illness has been impaired.

New research, led by Prof. LIU Bing and Prof. JIANG Tianzi from the Institute of Automation of the Chinese Academy of Sciences and their collaborators, may change this situation, though. The scientists have recently developed a novel imaging marker that may help in the personalized medicine of psychiatric disorders.

The study, published in Nature Medicine on Mar. 23, shows that abnormal striatal function can be a promising biomarker for the diagnosis of schizophrenia and treatment response.

In their search for suitable biomarkers, the scientists collected multimodal neuroimaging data from a total of 1100 individuals with schizophrenia and healthy controls from 2010-15.

Using the large dataset, the researchers first proposed the concept of "functional striatal abnormalities." They then used artificial intelligence technology on resting state fMRI data to map striatal dysfunction at the individual level.

The researchers showed, for the first time, that striatal dysfunction was effective in distinguishing schizophrenia patients and that such dysfunction was also responsible for poorer antipsychotic response.

Based on the newly developed biomarker, the researchers extended their research to other neuropsychiatric disorders. They showed that individuals with bipolar disorder also showed striatal dysfunction that overlapped with the dysfunction associated with schizophrenia.

After combining different levels of data, the researchers suggested that striatal dysfunction is related to the dopaminergic system and polygenic genetic risk for schizophrenia.

The study also evaluated using this biomarker to predict diagnostic labels and treatment responses across several different hospitals.

The scientists hope research on the biological underpinnings of psychiatric disorders will increase understanding of disease mechanisms as well as guide new drug development.

The Arctic polar night is a time when the sun remains below the horizon for a full 24-hour cycle. It is dark, but not completely. Nevertheless, the lack of light has long led researchers to assume that the organisms that live through this dark period are mostly dormant.

For a decade, an international team of researchers has been exploring the polar night to see exactly how organisms survive in the dark.

Over the course of their surveys, they've learned the only way they can really understand what's going on is to turn out the lights on their research vessels and rely on autonomous underwater vehicles that need no light to do their work.

And when they've done that, they've found birds that dive into the nearly pitch-black ocean to feast on bioluminescent plankton and krill, and deepwater fishes that normally live at great depths foraging in kelp beds just 2 metres deep, to name just a few.

"As the sun becomes less and less visible on the sky, the relative importance of the moon, the stars and even the aurora borealis becomes more and more important," says Jørgen Berge, a biologist at UiT - The Arctic University of Norway and the Norwegian University of Science and Technology (NTNU) who headed the international research team.

Now, Berge and his team, which also includes scientists from the UK, Canada and the US, has been able to quantify just how much light can affect the behaviour of all these creatures. Their results have been published in Communications Biology.

It turns out it doesn't take much light to affect organisms at all, the researchers found. Some reacted to light levels as low as one millionth that of daylight, including algal cells that entered a photoactive state a full six weeks before the return of sunlight. So much so that all previous biological surveys of everything from plankton to fish stocks may be fundamentally wrong, the researchers say.

"We have been able to document light-regulated biological processes that are still ongoing throughout the polar night," Berge said. "Many species of fish and zooplankton remain active and migrate vertically in the water column over a 24-hour period. These migrations are fully regulated by small changes in either sunlight or moonlight."

Geir Johnsen, a biologist at NTNU who was one of the authors of the paper, says this sensitivity was surprisingly extreme -- and has important consequences.

"Even the light from a research vessel, or a vessel estimating the stock size of zooplankton and fish, can influence organisms down to 200 metres below the ocean surface. They can either be attracted to the light or flee from it," Johnsen said. "All of this makes it very difficult to say anything accurate about behaviour or populations, and stock assessments of fish may be influenced by this at nighttime all over the world."

Johnsen is a key scientist at NTNU's "Autonomous Marine Operations and Systems (AMOS) Centre of Excellence, where he describes his role as "trying to merge enabling technology with the natural sciences.

In this situation, he says, where light is so critically important, the researchers need to use autonomous robots that don't need any artificial light and that can give them information that is not affected by artificial light.

This ability to study the dark without disturbing it is how the team was able to determine how profoundly light could upset behaviours that were normally tuned to the polar darkness.

This picture is complicated by global warming, the researchers say. Arctic sea ice is melting faster than at any time in recorded history, and growing human activity in the Arctic, with respect to fisheries, oil and gas, mineral extraction, new transport routes and tourism, is rapidly increasing as areas become free of ice.

Consequently, light pollution is pouring into the Arctic, and is now thought to be among the fastest growing sources of pollution in the region.

Johnsen says it's critical for researchers to learn as much as they can about how this ecosystem works before it is irreparably changed.

"About 50 percent of the oxygen that we breathe is from these microscopic algae in the world's oceans. Without those key groups there would be no life. Simple as that," he says.

Over this past year, the research team has also worked on the movie project "Into the Dark", which attempts to unravel the mystery of the polar night.

The movie mostly follows Berge, who is head of the Polar Night project and includes David McKee from the University of Strathclyde, Glasgow, and Johnsen. It premiered in Tromsø, Norway; in mid-January and will be shown at a number of film festivals throughout the year.

In order to colonize other organs and grow into metastases, tumor cells that detach from the parent tumor need to manipulate their new microenvironment and create a 'metastatic niche'. Scientists from the German Cancer Research Center and the Heidelberg Institute for Stem Cell Technology and Experimental Medicine* have now discovered that some cancer cells stimulate connective tissue cells in their environment to release transmitters that promote metastasis. This discovery plays a key role in better understanding how these dangerous metastases arise.

If cancer cells detach from a tumor and move around the body, they are entering enemy territory. Many detached cancer cells do actually die before they manage to colonize other tissues and form metastases, because the body's immune system is geared toward protecting healthy tissue from intruders of all kinds. Moreover, these migrant cancer cells can only survive if they manage to manipulate the cells in their new environment to create a metastatic niche that helps the migrant cancer cells survive.

Thordur Oskarsson and his team at the German Cancer Research Center (DKFZ) and at the Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH) are investigating how this metastatic niche arises. The scientists have now discovered both in cell cultures and in mice that some particularly aggressive breast cancer cells induce a situation similar to inflammation in lung tissue. This ultimately ensures that they can colonize the tissue and grow into metastases.

Specifically, the detached tumor cells release two inflammatory signaling molecules, known as interleukins, which stimulate fibroblasts in the lung to release two further inflammatory signaling molecules into the microenvironment: CXCL9 and CXCL10. In turn, these attach to a receptor molecule that several aggressive migrant cancer cells carry on their surface, marking a decisive step in the process of growing into a metastasis. These aggressive breast cancer cells thus benefit directly from the inflammation and from the signaling molecules CXCL9 and CXCL10.

"Interestingly, the very tumor cells that stimulate the fibroblasts to produce CXCL9 and CXCL10 also have the relevant receptor for these cytokines and thus benefit from the process," explained Maren Pein, lead author of the study. "That underlines how crucial the cellular communication between the detached cancer cells and the fibroblasts in their new microenvironment is for metastasis."

Furthermore, the scientists prevented metastasis in the lung in an experimental setting by treating mice with an inhibitor that blocked the receptor molecule on the cancer cells.

Tumor tissue samples from patients show that this cellular interaction probably plays a role in breast cancer patients too: Thus cancer cells that carry the relevant surface receptor and can therefore harness the interaction with fibroblasts to form metastases are also found in patients with metastatic breast cancer.

Oskarsson emphasized that it was still too early to identify a new treatment approach from these findings. "Our work is initially designed to help understand the underlying mechanisms that are necessary for metastases to actually arise," he explained. "But we obviously hope that this better understanding will lead to us being able to prevent metastases some time in the future."