Culture

A recent study examining perceptions of power suggests that individuals with lower socioeconomic statuses are more likely to have a negative view of policy or decision-makers.

Leanne ten Brinke, an assistant professor of psychology in the Irving K. Barber Faculty of Arts and Social Sciences and study co-author, says the study was inspired by her time living in the United States during the 2016 presidential election.

"I was a post-doc at University of California Berkley and remember being so struck by the different approaches to power being used by then-candidates Hillary Clinton and Donald Trump," she explains. "It occurred to me then that people have very different perspectives on what it takes to get to the top."

In a survey of over 1,000 participants, the study looked at their perceptions of two viable paths to power--one through the use of coercion, manipulation and fear-mongering, and the other rooted in collaboration and respect.

"We were interested in how socioeconomic status might affect one's view on how power is gained and maintained," says ten Brinke. "We also wondered how identifying with a theory of power might be associated with one's interpersonal and societal trust."

Results showed those with lower socioeconomic statuses were generally less-trusting and more inclined to hold a more coercive and less collaborative view of power, while people with higher socioeconomic statuses were more trusting and embraced the opposite view.

"We also found that people held one theory of power or the other--but not both simultaneously," explains ten Brinke. "As income inequality continues to rise, and we have a widening gap between the powerful and powerless, these results help us understand how these groups view the human hierarchy in which they live."

Though it's unclear exactly where the 'cut-off' is for one to have the income and status that leads to a more positive view on power, ten Brinke says this research provides much-needed insight into why people carry such differing views.

"I think a lot of it comes down to trust. If we can change peoples' theories of power, perhaps we can increase trust where it's due," she says, adding that further investigation may be helpful in understanding involvement in the democratic process or why some follow public health guidelines when others don't.

"There's considerable research that shows low socioeconomic individuals are less likely to vote than high," she says.

"Part of that is structural--it may be more difficult for them to get time off work--but I suspect theories of power play into it as well. If you think powerful people are coercive and corrupt and you can't trust any of them, perhaps you think it doesn't matter who is in office--but that's not a healthy democracy, so I see this research as a building block for future work in this area."

Forest leaves are teeming with bacterial life - but despite the vast extent of bacteria-covered foliage across the world, this habitat, known as the phyllosphere, remains full of mysteries. How do bacteria spread from tree to tree? Do certain types of bacteria only live on certain types of trees?

A new paper published in the Ecological Society of America's journal Ecological Monographs addresses some of these questions. The findings reveal that the leaf microbiomes of sugar maple trees vary across the species' range, changing in accordance with the types of trees in the surrounding "neighborhood."

Geneviève Lajoie, now a post-doctoral researcher at the University of British Columbia and the paper's lead author, performed the research as a Ph.D. student at the Université du Québec à Montréal. She and her field assistant spent a summer in hot pursuit of bacteria-covered foliage, camping at remote parks and rushing to get their leaf samples back to the lab for analysis before new conditions altered the leaves' resident microbes.

The team sampled foliage at sites across Québec, Ontario and the northeastern United States. Lajoie's analysis zeroed in on the iconic sugar maple - a species that is abundant at the southern end of the study range, but tapers off at more northern latitudes where conifers dominate the landscape. In fact, at the northern reaches of the study range, at sites like Monts-Valin National Park, sugar maples become anomalous enough that tracking them down among their evergreen neighbors was a challenge.

"To reach the site, we drove up north from Québec City and witnessed the gradual transition from the mixed deciduous forest of the Saint Lawrence Valley to a boreal landscape dominated by conifers," Lajoie said. "Going sampling over the next days, we were looking for sugar maple populations - our focal species. Even though we knew it could be found in the park despite it being the northern limit of its range, encountering these beautiful trees seemingly out of place but still thriving were particularly amazing moments for me."

However, despite being outliers on a conifer-dominated landscape, these northernmost sugar maple trees had adopted leaf microbiomes that blended in with their coniferous neighbors. LaJoie found a pattern along the latitudinal gradient of her study area: southern sugar maples, which are surrounded by lots of other sugar maples, tended to share a relatively similar microbiome - one that was distinct from other tree species in the area. But in more northern areas, where sugar maple trees are few and far between, the species hosted bacterial communities that resembled the microbiomes of other more dominant species.

The observations echo similar patterns that have been observed among animal microbiomes. Ground-dwelling animals, for instance, tend to have relatively similar microbiomes, possibly through increased contact with the feces of other animals, while canopy-dwelling animals have gut microbiomes that are less similar to each other.

While gut microbiomes are a hot research topic in the human health sciences, the forest phyllosphere remains a study system that is not well understood - and according to Lajoie, the fields of plant ecology and microbiology have been growing mostly in parallel for many years. This study's findings provide a more complete picture of the plant-microbe relationship: what kinds of bacteria go on which trees, and how this pattern varies depending on how well a tree fits in with the crowd.

It is already possible to produce food with a 3D printer, potentially delivering products that suit consumer preferences regarding taste, texture, cost, convenience, and nutrition. In the near future, it will be possible to produce food with personalized shapes, textures, flavors, and colors considered attractive and healthy for children and the elderly, for example.

A group of researchers at the University of São Paulo's Luiz de Queiroz College of Agriculture (ESALQ-USP) in Brazil, partnering with colleagues in France at Nantes Atlantic College of Veterinary Medicine, Food Science and Engineering (Oniris) and the National Institute for Research on Agriculture, Food and Environment (INRAE), have made strides toward achieving this goal. They are developing hydrogels based on modified starch for use as "ink" in 3D printing of foods.

Recent results of the project, supported by FAPESP (São Paulo Research Foundation), are published in the journal Food Research International. "In the past few years we've developed different technologies to modify starch and obtain gels with ideal characteristics for use as 'ink' to produce food by 3D printing," Pedro Esteves Duarte Augusto, a professor at ESALQ-USP and principal investigator for the project, told Agência FAPESP.

The first gels produced by the researchers were based on cassava starch. They themselves developed the method used to modify the structure and properties of the starch with ozone during a previous project also supported by FAPESP.

They produced ozone by applying an electrical discharge to oxygen, bubbled the gas in a container with a mixture of water and cassava starch in suspension, and dried the mixture by removing the water. The result was modified starch.

By varying aspects of the process such as ozone concentration, temperature, and time, they were able to obtain gels with different properties in terms of the right consistency for use in 3D printing.

"Control of the conditions enabled us to obtain weaker gels for other applications and firmer gels that are ideal for 3D printing because they retain the shape of the printed structure without flowing or losing moisture," Augusto said.

In the past two years, the researchers have developed another starch modification method. This involves dry heating of cassava and wheat starch in an oven while controlling both temperature and time.

Using the new method they were also able to obtain gels based on modified starch that displayed optimal printability, defined as the ability to make a 3D object by additive manufacturing (layer-by-layer deposition) and to maintain its structure once printed. Dry heat treatment also extended the textural possibilities of printed samples based on wheat starch hydrogels.

"We obtained good results with both methods. They're simple, cheap and easy to implement on an industrial scale," Augusto said.

Samples of gel based on cassava and wheat starch were printed at Oniris and INRAE in France via a project to develop functional starch-based gels for 3D printing funded by the Pays de la Loire regional innovation agency under a program called "Food 4 tomorrow".

Through the partnership with French scientists, ESALQ-USP researcher Bianca Chieregato Maniglia conducted postdoctoral research at Oniris and INRAE, applying the ozone and dry heating techniques to produce gels based on modified cassava and wheat starch for 3D printing of foods.

The techniques were developed with the collaboration of other researchers in ESALQ-USP's Process Engineering Research Group (Ge²P).

"The combined experience of all the researchers involved in the project enabled us to obtain gels with better printability, resulting in foods with better shape, definition and texture, which are essential parameters for product acceptability," Maniglia said.

Novel ingredientes

The ESALQ-USP group now plans to study other methods of modification and sources for the production of 3D food printing gels. ESALQ-USP has recently purchased a 3D printer, which they will use to produce the structures developed with the new gels.

The gels based on modified cassava and wheat starch can be used to print other things apart from food, such as biomedical products including drug capsules and nutraceuticals - foods designed not only to nourish but also to confer health benefits.

"We've demonstrated the feasibility of food production by 3D printing and fabrication of tailor-made ingredients. Now we plan to extend the applications and test other raw materials," Augusto said.

HOUSTON - (Dec. 3, 2020) - That carbon nanotubes fluoresce is no longer a surprise. Finding a second level of fluorescence is surprising and potentially useful.

How does it work? Wait for it.

The Rice University lab of Bruce Weisman, a professor of chemistry who led the pioneering discovery of nanotube fluorescence in 2002, found that single-walled nanotubes emit a delayed secondary fluorescence when triggered by a multistep process in a solution with dye molecules and dissolved oxygen.

The delay is only microseconds, but it's enough to be detected with some effort.

The complex process is detailed by Weisman, lead author and Rice alumnus Ching-Wei Lin, and research scientist Sergei Bachilo in the Journal of the American Chemical Society.

The reaction begins when light excites a solution containing a dye called rose bengal. Oxygen molecules dissolved in the solution capture energy from the dye, forming an energized form of O2. These then transfer their energy to nanotubes, where excitons -- quasiparticles made of electrons and electron holes -- are generated in their triplet state. With a bit of added thermal energy, those excitons get promoted to a higher energy singlet state that emits the observed fluorescence.

"For a number of years, we have been looking at interesting effects involving nanotubes and oxygen," Weisman said. "We've found quite a range of things that can happen, from physical effects like this energy transfer or the reversible quenching of fluorescence, to the triggering of chemical reactions between nanotubes and DNA. So this study was part of a larger program of exploration."

Their ability to excite dissolved oxygen molecules prompted the researchers to see how that would affect adjacent nanotubes, Weisman said.

"We make singlet oxygen by exciting a dye molecule with visible light, and then the oxygen deactivates the dye and gets excited itself," he said. "That idea goes back decades in photophysics and is very conventional. What's unusual here is that the singlet oxygen interacts with the nanotube to directly make triplet-state excitations in the tube. Those triplet states have been pretty elusive.

"Triplet states of organic molecules are the longest-lived excited states," Weisman said. "Their lifetimes are orders of magnitude greater than the singlet excited states, so they can hang around long enough to bump into something else and undergo chemical reactions.

"But because nanotube triplet states don't emit light or directly absorb light very well, they are tricky to study and not too much is known about them," he said. "What we've been doing is trying to understand them a little better."

Triggering fluorescence still required an extra step. "Just by random thermal agitation in their surroundings, these guys can sometimes get kicked up to the bright singlet state, and then they can tell you they're there by spitting out a photon," Weisman said.

Because the triplet state can last 10 microseconds or so, that upconverted emission is called delayed fluorescence.

The researchers had to find a way to detect the relatively weak effect amid the nanotubes' bright primary fluorescence. "It was like trying to see a dim object right after being blinded by a bright camera flash," Weisman said. "We had to devise some special instrumentation."

One device "is basically a fast mechanical shutter" that covers the short-wave infrared (SWIR) spectrometer during the bright flash and then quickly opens up, a kind of reverse camera that goes from covered to open in seven microseconds. The other device, he said, is a sensitive detector that's triggered with an electronic signal and measures how the weak emission fades away over time. "These systems were both built by Ching-Wei, who's a terrific experimentalist," he said.

Weisman and colleagues have employed nanotube fluorescence in medical imaging technologies and in nanotube-based smart skin to measure strain in surfaces, among other applications. He said the new discovery could eventually find its way into optoelectronics and solar energy.

"There's not a direct step where somebody's going to read this and make a new, more efficient device," Weisman said. "But this fundamental knowledge of processes and properties is the foundation on which new technologies are built."

More than 40 years since they launched, the Voyager spacecraft are still making discoveries.

In a new study, a team of physicists led by the University of Iowa report the first detection of bursts of cosmic ray electrons accelerated by shock waves originating from major eruptions on the sun. The detection, made by instruments onboard both the Voyager 1 and Voyager 2 spacecraft, occurred as the Voyagers continue their journey outward through interstellar space, thus making them the first craft to record this unique physics in the realm between stars.

These newly detected electron bursts are like an advanced guard accelerated along magnetic field lines in the interstellar medium; the electrons travel at nearly the speed of light, some 670 times faster than the shock waves that initially propelled them. The bursts were followed by plasma wave oscillations caused by lower-energy electrons arriving at the Voyagers' instruments days later--and finally, in some cases, the shock wave itself as long as a month after that.

The shock waves emanated from coronal mass ejections, expulsions of hot gas and energy that move outward from the sun at about one million miles per hour. Even at those speeds, it takes more than a year for the shock waves to reach the Voyager spacecraft, which have traveled further from the sun (more than 14 billion miles and counting) than any human-made object.

"What we see here specifically is a certain mechanism whereby when the shock wave first contacts the interstellar magnetic field lines passing through the spacecraft, it reflects and accelerates some of the cosmic ray electrons," says Don Gurnett, professor emeritus in physics and astronomy at Iowa and the study's corresponding author. "We have identified through the cosmic ray instruments these are electrons that were reflected and accelerated by interstellar shocks propagating outward from energetic solar events at the sun. That is a new mechanism."

The discovery could help physicists better understand the dynamics underpinning shock waves and cosmic radiation that come from flare stars (which can vary in brightness briefly due to violent activity on their surface) and exploding stars. The physics of such phenomena would be important to consider when sending astronauts on extended lunar or Martian excursions, for instance, during which they would be exposed to concentrations of cosmic rays far exceeding what we experience on Earth.

The physicists believe these electrons in the interstellar medium are reflected off of a strengthened magnetic field at the edge of the shock wave and subsequently accelerated by the motion of the shock wave. The reflected electrons then spiral along interstellar magnetic field lines, gaining speed as the distance between them and the shock increases.

In a 2014 paper in the journal Astrophysical Letters, physicists J.R. Jokipii and Jozsef Kota described theoretically how ions reflected from shock waves could be accelerated along interstellar magnetic field lines. The current study looks at bursts of electrons detected by the Voyager spacecraft that are thought to be accelerated by a similar process.

"The idea that shock waves accelerate particles is not new," Gurnett says. "It all has to do with how it works, the mechanism. And the fact we detected it in a new realm, the interstellar medium, which is much different than in the solar wind where similar processes have been observed. No one has seen it with an interstellar shock wave, in a whole new pristine medium."

Scientists have created an evolutionary model to predict how animals should react in stressful situations.

Almost all organisms have fast-acting stress responses, which help them respond to threats - but being stressed uses energy, and chronic stress can be damaging.

The new study - by an international team including the University of Exeter - suggests most animals remain stressed for longer than is optimal after a stress-inducing incident.

The reasons for this are not clear, but one possibility is that there is a limit to how quickly the body can remove stress hormones from circulation.

"We have created one of the first mathematical models to understand how organisms have evolved to deal with stressful events," said Dr Tim Fawcett, of the University of Exeter.

"It combines existing research on stress physiology in a variety of organisms with analysis of optimal responses that balance the costs and benefits of stress.

"We know stress responses vary hugely between different species and even among individuals of the same species - as we see in humans.

"Our study is a step towards understanding why stress responses are so variable."

The researchers define stress as the process of an organism responding to "stressors" (threats and challenges in their environment), including both detection and the stress response itself.

A key point highlighted in the study is the importance of how predictable threats are.

The model suggests that an animal living in a dangerous environment should have a high "baseline" stress level, while an animal in a safer environment would benefit from being able to raise and reduce stress levels rapidly.

"Our approach reveals environmental predictability and physiological limits as key factors shaping the evolution of stress responses," said lead author Professor Barbara Taborsky, of the University of Bern.

"More research is needed to advance scientific understanding of how this core physiological system has evolved."

A new study reveals how bacteria control the chemicals produced from consuming 'food.' The insight could lead to organisms that are more efficient at converting plants into biofuels.

The study, authored by scientists at UC Riverside and Pacific Northwest National Laboratory, has been published in the Journal of the Royal Society Interface.

In the article, the authors describe mathematical and computational modeling, artificial intelligence algorithms and experiments showing that cells have failsafe mechanisms preventing them from producing too many metabolic intermediates.

Metabolic intermediates are the chemicals that couple each reaction to one another in metabolism. Key to these control mechanisms are enzymes, which speed up chemical reactions involved in biological functions like growth and energy production.

"Cellular metabolism consists of a bunch of enzymes. When the cell encounters food, an enzyme breaks it down into a molecule that can be used by the next enzyme and the next, ultimately generating energy," explained study co-author, UCR adjunct math professor and Pacific Northwest National Laboratory computational scientist William Cannon.

The enzymes cannot produce an excessive amount of metabolic intermediates. They produce an amount that is controlled by how much of that product is already present in the cell.

"This way the metabolite concentrations don't get so high that the liquid inside the cell becomes thick and gooey like molasses, which could cause cell death," Cannon said.

One of the barriers to creating biofuels that are cost competitive with petroleum is the inefficiency of converting plant material into ethanol. Typically, E. coli bacteria are engineered to break down lignin, the tough part of plant cell walls, so it can be fermented into fuel.

Mark Alber, study co-author and UCR distinguished math professor, said that the study is a part of the project to understand the ways bacteria and fungi work together to affect the roots of plants grown for biofuels.

"One of the problems with engineering bacteria for biofuels is that most of the time the process just makes the bacteria sick," Cannon said. "We push them to overproduce proteins, and it becomes uncomfortable -- they could die. What we learned in this research could help us engineer them more intelligently."

Knowing which enzymes need to be prevented from overproducing can help scientists design cells that produce more of what they want and less of what they don't.

The research employed mathematical control theory, which learns how systems control themselves, as well as machine learning to predict which enzymes needed to be controlled to prevent excessive buildup of metabolites.

While this study examined central metabolism, which generates the cell's energy, going forward, Cannon said the research team would like to study other aspects of a cell's metabolism, including secondary metabolism -- how proteins and DNA are made -- and interactions between cells.

"I've worked in a lab that did this kind of thing manually, and it took months to understand how one particular enzyme is regulated," Cannon said. "Now, using these new methods, this can be done in a few days, which is extremely exciting."

The U.S. Department of Energy, seeking to diversify the nation's energy sources, funded this three-year research project with a $2.1 million grant.

The project is also a part of the broader initiatives under way in the newly established UCR Interdisciplinary Center for Quantitative Modeling in Biology.

Though this project focused on bacterial metabolism, the ability to learn how cells regulate and control themselves could also help develop new strategies for combatting diseases.

"We're focused on bacteria, but these same biological mechanisms and modeling methods apply to human cells that have become dysregulated, which is what happens when a person has cancer," Alber said. "If we really want to understand why a cell behaves the way it does, we have to understand this regulation."

SPOKANE, Wash. - Scientists used human white blood cell membranes to carry two drugs, an antibiotic and an anti-inflammatory, directly to infected lungs in mice.

The nano-sized drug delivery method developed at Washington State University successfully treated both the bacterial growth and inflammation in the mice's lungs. The study, recently published in Communications Biology, shows a potential new strategy for treating infectious diseases, including COVID-19.

"If a doctor simply gives two drugs to a patient, they don't go directly to the lungs. They circulate in the whole body, so potentially there's a lot of toxicity," said Zhenjia Wang, the study's corresponding author and an associate professor in WSU's College of Pharmacy and Pharmaceutical Sciences. "Instead, we can load the two types of drugs into these vesicles that specifically target the lung inflammation."

Wang and his research team have developed a method to essentially peel the membrane from neutrophils, the most common type of white blood cells that lead the body's immune system response. Once emptied, these membranes can be used as nanovesicles, tiny empty sacks only 100 to 200 nanometers wide, which scientists can then fill with medicine.

These nanovesicles retain some of the properties of the original white blood cells, so when they are injected into a patient, they travel directly to the inflamed area just as the cells would normally, but these nanovesicles carry the medicines that the scientists implanted to attack the infection.

In this study, first author Jin Gao, a WSU research associate, loaded the nanovesicles with an antibiotic and resolvinD1, an anti-inflammatory derived from Omega 3 fatty acids, to treat lungs infected by P. aeruginosa, a common potentially fatal pathogen patients can catch in hospital settings. The researchers used two drugs because lung infections often create two problems, the infection itself and inflammation created by a strong immune system response.

Toxicity studies and clinical trials would have to be conducted before this method could be used in human patients, but this study provides evidence that the innovation works for lung inflammation. If the method is ultimately proven safe and effective for humans, Wang said the nanovesicles could be loaded with any type of drug to treat a range of infectious diseases, including COVID-19.

"I think it's possible to translate this technology to help treat COVID-19," said Wang. "COVID-19 is a virus, not a bacterial pathogen, but it also causes an inflammation response in the lung, so we could load an antiviral drug like remdesivir into the nanovesicle, and it would target that inflammation."

Scientists have identified 3 bacteriophages, 47 bacterial species, and 50 fecal metabolites that were significantly more or less abundant in people with major depressive disorder (MDD) compared with healthy controls, according to a study in 311 individuals. The findings provide evidence that MDD may be characterized by gut microbiome disturbances. Jian Yang and colleagues also developed a marker panel based on the bacterial, viral, and metabolic MDD signatures they uncovered, which effectively differentiated between patients with MDD and controls. A similar biomarker-based diagnostic tool may help physicians better diagnose MDD, offering a companion to clinical interviews, which frequently result in misdiagnosis. While previous studies have observed gut microbiome disturbances in people with MDD, researchers had not yet identified the bacterial species that differ in people with this common mental disorder or explored whether intestinal viruses are also disrupted in MDD. To learn more about how MDD specifically affects microbial and viral communities in the gut, as well as fecal metabolic signatures, Yang et al. analyzed genetic material from 311 fecal samples taken from 156 patients with MDD and 155 healthy controls and performed large-scale gas chromatography-mass spectrometry-based analyses of the fecal metabolites. The researchers found distinct differences in the bacterial composition of MDD patients compared with controls, observing that they contained higher levels of bacterial species belonging to the genus Bacteroides and lower levels of species belonging to Blautia and Eubacterium. A greater Bacteroides presence in the gut microbiome could account for previous observations that people with MDD have higher cytokine levels and increased inflammation, while fewer Blautia would result in a loss of anti-inflammatory benefits. Although Yang et al. did not find significant differences between the viral composition of the MDD and control groups, they did identify 3 bacteriophages that were less abundant in MDD patients. The authors suggest future studies explore the role of these phages.

Despite the increase in use of e-cigarettes among adolescents, cigarette and smokeless tobacco prevalence declined more rapidly between 2012 and 2019 than in previous periods, according to a new study.

The analysis by the University of Michigan and Georgetown University shows that past 30-day and daily use of both cigarettes and smokeless tobacco fell more rapidly since 2012, even as e-cigarette use began to increase--leading to historical low levels of both cigarette use and smokeless tobacco among teens in the United States.

"While the increases in e-cigarettes are indeed concerning and is something we need to address and reverse, the decreases in other tobacco products, in particular, cigarettes--the most concerning form of tobacco use--are accelerating," said lead researcher Rafael Meza, associate professor of epidemiology and global health at U-M's School of Public Health.

"We are in a stage where cigarette smoking is going away. That's something that we need to highlight and celebrate. This acceleration in the decrease occurs across grades, across races, across sexes. So it's really occurring across the board and suggests that it's a general pattern, that kids are just not into smoking anymore."

Meza and colleagues wanted to understand long-term and recent trends in cigarette smoking and smokeless tobacco product use among adolescents by grade (8th, 10th, 12th), gender and race. Utilizing data from the nationally representative Monitoring the Future survey at U-M from 1991 to 2019, they examined the use prevalence of tobacco products in the last 30 days among key sociodemographic groups, identifying change of trend years for U.S. secondary and high schools.

They found that daily smoking prevalence among 12th grade boys increased 4.9% annually 1991 to 1998, but saw annual declines of 8% between 1998 and 2006 and 1.6% from 2006 to 2012. However, from 2012 to 2019, prevalence declined at a 17% annual rate. Overall, Daily smoking prevalence among 12th graders fell to about 2% by 2019.

"This is an astoundingly low rate, and our goal from a public health perspective should be to keep smoking at this rate or lower," said researcher David Levy, professor of oncology at Georgetown.

Similar results were observed for both boys and girls in all grades and for both African American and white teens. Smokeless tobacco use showed more variability through 2012, followed by consistent declines in the last five years. MTF data also shows similar rapid decreases in cigar and cigarillo use among adolescents in recent years, suggesting a general pattern across traditional tobacco products.

Meza said the results are important because while e-cigarettes are concerning on their own, there have been concerns that the increase in use of e-cigarettes could result in an uptick in the use of other tobacco products, including cigarette smoking that could potentially upend the declines we've seen the last couple of decades.

"But in contrast, what we found is that the decline in smoking has accelerated," he said. "So I think the good news is that the rapid increase in e-cigarette use has not yet resulted in a reversal of the decreasing trends of cigarette smoking and smokeless tobacco use, and if anything, those trends have accelerated."

Almost a decade of civil and military unrest has left Syrian children mentally scarred, angry and traumatised, according to new research.

In the largest such survey yet carried out, researchers questioned more than 1,300 secondary school children in the Syrian capital, Damascus, about the impact that nine years of exposure to the conflict has had.

They found negative impacts in more than half, with high levels of post-traumatic stress disorder (PTSD), problematic anger and other, significant mental health issues.

The impact appeared worse in girls, who reported a higher predominance of PTSD and a worse quality of life.

The report suggests that the longer the crisis continues, the more persistent the impact will be, making mental recovery even harder.

The study, Posttraumatic stress disorder (PTSD), anger, and mental health of school students in Syria after nine years of conflict: a large-scale school-based study, provides a detailed analysis of the mental damage caused by war, the disparities between girls and boys, and the overall condition of Syrian students.

Looking at the extent of the damage, the study involved a total of 1,369 students, in grades 10 and above, living and studying for the past nine years in the city of Damascus.

Published in the Cambridge journal, Psychological Medicine, it looks at children who have grown up during the war and experienced daily traumatic events from the conflict and a deteriorating economy.

The study was carried out in seven schools over 12 months, starting in March 2019. Questionnaires were distributed and completed in class, with experienced data collectors on hand to ensure anonymity and to explain if anything was unclear to the students.

The survey covered students' socio-economic status; their health-related quality of life, including general, physical and mental health; the kinds of social and emotional support available to them; whether they had been in danger or distress, or suffered other traumatic events like the loss of a home or people close to them; and questions designed to assess their levels of anger and the likelihood of PTSD.

The answers revealed that around half of the students had changed where they lived due to war, with 58% reporting that they had been directly endangered, 40% saying they had lost someone close, and 61% reporting distress from war noises.

Analysis showed more than half of the students, 53%, had probable PTSD, while 62% suffered from problematic anger. Around 46% declared having a fair or worse general health, and 61% moderate or severe mental health issues.

Dr. Ameer Kakaje, lead author on the paper, believes the true prevalence of these problems could be even higher, as the study was only in Damascus, not in areas where populations may be even more severely affected. It was also unable to reach children who had dropped out of school.

He said: "I am a Syrian who lived most of his life in Syria and witnessed most of the suffering in person, especially as my last three years at high school and all of my university studies were during the war.

"The critically high prevalence of PTSD and problematic anger shocked me. We are talking about young people who are 18 and under and who should be healthy. But these high numbers are just a glimpse of what is going on in the Syrian community and how much they are mentally suffering without any means of dealing with it."

Further analysis found girls reported worse mental and physical health than boys, had a higher probability of PTSD and a worse quality of life. Again, Dr Kakaje suspects the figures may hide the true scale of the problem.

He said: "When screening for problematic anger, there was no difference between genders, which could indicate that due to gender stigma, boys might have underestimated their symptoms when they filled in the self-reporting scales. As anger is not stigmatised, they were free to declare their problems and thus both genders might have been severely affected. This may also mean that both genders may suffer mentally, but boys might have not expressed these feelings in ways other than through anger."

PITTSBURGH, Dec. 2, 2020 - A mutation in the gene regulating circadian rhythms increases self-administration of cocaine in mice, University of Pittsburgh Schools of the Health Sciences researchers found in a paper published today in the Journal of Neuroscience. The study reveals a molecular basis for the deep and fundamental connection between the disruption in circadian rhythms and predisposition to substance abuse.

The scientists trained mice carrying a mutation in the NPAS2 gene--one of the key genes that controls sleep and wake cycles--to self-administer a dose of cocaine. To examine the role of NPAS2 in drug-taking, researchers then recorded changes in the mice's behavior related to developing a psychostimulant disorder.

Mice with NPAS2 mutation showed increased self-administration of cocaine. Female mice generally had a greater response than males, and it further increased at night--an active phase of the mouse's daily activity cycle.

"We were surprised to see just how much the NPAS2 mutation affected drug-taking behaviors," said lead author Lauren DePoy, Ph.D., a postdoctoral fellow at the Center for Neuroscience at Pitt. "It emphasizes that any kind of disruption in circadian rhythms, either environmental or genetic, can cause profound changes to the brain that predispose individuals to substance abuse."

Circadian disruptions, or disturbances in the internal biological clock in cells and tissues of the body, are closely linked to substance use disorders. Previous studies have shown that chronic drug abuse alters circadian rhythms and that disrupted circadian genes can alter drug sensitivity, both feeding into the vicious cycle of substance use vulnerability.

To approximate the way a psychostimulant addiction develops in humans, researchers chose to use a model of cocaine self-administration in mice. Animals were implanted with a jugular intravenous catheter which supplied a fixed dose of cocaine into the bloodstream whenever a mouse would push on a lever inside the experimental chamber.

A push of the lever was timed with noise and light cues, which allowed researchers to study if presentation of cues alone was enough to trigger drug-seeking behavior, and how long it took for the animal to change their behavior if cues and drug weren't present.

In addition to finding sex-based differences in behavioral changes related to cocaine administration, the researchers found that striatum--a critical component of the reward system of the brain--was preferentially activated in NPAS2-mutant females.

Scientists say that even though humans do not harbor the same mutation in the NPAS2 gene, other genetic variances in circadian genes are linked to differences in sleep-wake patterns and predisposition to psychiatric disorders, such as depression or seasonal affective disorder.

"Circadian genes are expressed in regions of the brain that control reward, motivation and mood," said senior author Colleen McClung, Ph.D., professor of psychiatry and clinical and translational science at Pitt. "Defining the mechanisms of how those genes control activity and function of the brain can help us develop interventions that can bring disturbed rhythms back to normal and fix downstream consequences of psychostimulant disorders."

The origin of glass beads dates back to early ancient times. The chemical composition of the beads and their morphological and technical characteristics can reveal where they come from; this information can then be used to reconstruct the trade channels between glass production areas and the sites where the beads were used at different times. Archaeologists from the University of Geneva (UNIGE), working in partnership with the Institut de Recherche sur les Archéomatériaux at the Centre Ernest-Babelon in Orléans, France, analysed 16 archaeological glass beads found at three rural sites in Mali and Senegal from between the 7th and 13th centuries AD. In the journal Plos One, the scientists demonstrate that the glass they are made of probably came from Egypt, the Levantine coast and the Middle East. The results show that international trade linking Africa to Europe and Asia during the development of the large West African state configurations did not stop at the great urban centres located along the Niger River: it also connected with local and regional trade. In this way, an extensive network including sub-Saharan rural areas and trans-Saharan trade routes took shape.

The glass beads uncovered in Africa do not only come from the well-known junk cargoes shipped by boat to be exchanged for slaves around the 18th century. Their provenance is much older and their places of origin many and diverse. In western sub-Saharan Africa, the beads have been found in urban archaeological sites from the mediaeval period along the Niger River. Several Arabic texts describe these trade routes crossing the Sahara and connecting the African continent to Europe and Asia. &laquoTrans-Saharan caravans traded horses, guns, luxury objects and salt for ivory, gold and slaves», explains Anne Mayor, a researcher in the Anthropology Unit in UNIGE's Faculty of Sciences.

Members of the &laquoArchaeology and Population in Africa Laboratory of UNIGE have been carrying out archaeological excavations for several decades at sites in central Mali and eastern Senegal, including old cemeteries and villages. They have investigated the evolution of lifestyles and techniques. A total of 16 glass beads has been unearthed at three of these sites dating from between the 7th and 13th centuries AD. To understand their provenance and form a picture of what trade was like at a time when the first African kingdoms were developing, the archaeologists embarked on an analysis of their morphological and technical characteristics together with their chemical composition.

Beads: a type of &laquocrystal ball»

Three main components are required for the production of glass. The primary ingredient is silica, which is obtained from quartz ore or sand. This has to be melted, but since its melting point is too high, mineral or vegetable &laquoflux» is added to help the process. Finally, lime from limestone rocks or shells serves as a stabiliser for the glass structure. &laquoBy analysing the chemical composition of the glass, we can begin to understand the origin of the raw materials used to manufacture it and, in some cases, the period when it was produced», states the first author of the study, Miriam Truffa Giachet, for whom this work is an integral part of her UNIGE doctoral thesis.

&laquoIt's also important to understand that the production of glass beads involves several stages, generally located in different places,» continues the Geneva-based researcher. The first step consists of collecting the raw materials, which are then transported to a primary production centre where the raw glass is made. This is then transported to secondary centres to manufacture glass objects before being distributed to various sites through trade. The scientists cross-referenced the results of the chemical analysis of the beads with historical sources and data from archaeological excavations, thereby obtaining precise information about the origin of the beads.

The lab meets the field

The study's originality lies in the cross-analysis of archaeological field data and laboratory data to further our understanding of African archaeological objects. The scientists used laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to evaluate the chemical composition of the beads without damaging them, thanks to laser sampling that tests very small quantities of material. In this way, the probable origins of the beads were identified: Egypt, the Levantine coast and the Middle East.

It follows that sub-Saharan agropastoralists (whose dwellings and tombs archaeological excavations have found traces of) were incorporated into very broad trade networks, as revealed by the presence of objects from distant sources. These locations were in a peripheral position in relation to the regional power centres, but at least one of them, in eastern Senegal, was close to gold mines - a resource that made a significant contribution to their wealth. It is interesting to note that none of the beads analysed had the characteristics typical of the solitary African primary production centre active at the time, in Nigeria, despite the fact that there was internal east-west trade.

Sub-Saharan Africa: connected to the rest of the world

The study adds weight to the idea that at this time prestigious goods circulated through trade routes linking sub-Saharan Africa to the rest of the world. &laquoThe western popular imagination thinks that Africa was disconnected beyond the Sahara, but this was clearly not the case! It was fully integrated into a large international network that linked Africa, Europe and Asia. It was connected to local trade that brought goods of distant origin to the hinterland,» concludes Dr Mayor.

Replacing red meat with high quality plant foods such as beans, nuts, or soy may be associated with a modestly reduced risk of coronary heart disease (CHD), suggests a study published by The BMJ today.

Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.

Substantial evidence suggests that high consumption of red meat, especially processed red meat, such as bacon, hot dogs, sausages and salami, is associated with an increased risk of death and major chronic diseases, including coronary heart disease.

Studies that show inconsistent results often fail to compare red meat with similar protein and energy sources.

To address these problems in study design and analysis, a team of US researchers examined the relation between total, processed, and unprocessed red meat and risk of CHD and estimate the effects of substituting other protein sources for red meat with CHD risk.

Their findings are based on data from 43,272 US men (average age 53) from the Health Professionals Follow-Up Study who were free from cardiovascular disease and cancer when they enrolled.

Participants filled in a detailed diet questionnaire in 1986 and every four years thereafter, up to 2016, and provided information on their medical history and lifestyle.

Medical records were used to track CHD events (fatal and non-fatal) over this 30-year period. During this time, 4,456 CHD events were documented of which 1,860 were fatal.

After taking account of other cardiovascular disease risk factors, the researchers found that for every one serving per day, total red meat was associated with a modest (12%) higher risk of CHD. Similar associations were seen for unprocessed (11% higher risk) and processed red meat (15% higher risk).

However, compared with red meat, intake of one serving per day of combined plant protein sources, including nuts, legumes (such as peas, beans and lentils), and soy was associated with a 14% lower risk of CHD.

This risk was lower still (18%) among men over the age of 65, and when compared with processed red meat (17%).

Substituting whole grains and dairy products (such as milk, cheese and yoghurt) for total red meat and eggs for processed red meat were also associated with lower CHD risk. This association was particularly strong among younger men, in whom the replacement of red meat with egg was associated with a 20% lower risk of CHD.

Replacing red meat with total fish was not associated with CHD risk. But the researchers say this could be due to cooking method (ie. deep frying) and the fact that this food group also included processed fish products.

This is an observational study, so can't establish cause, and despite adjusting for important personal and lifestyle factors, the researchers can't rule out the possibility that other unmeasured factors might have influenced their results.

What's more, study participants were mainly white health professionals so the findings may not be more widely applicable.

Nevertheless, this was a large study with repeated measures of diet during 30 years of follow-up, suggesting that the findings withstand scrutiny.

As such, they say their study shows that greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.

Substituting whole grains or dairy products for total red meat and substituting eggs for processed red meat were also associated with a lower CHD risk, they add.

"These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources," they explain.

This would also have important environmental benefits, they conclude.

A new research study from the March of Dimes Prematurity Research Center led by investigators at the University of Chicago has identified new genetic markers associated with gestational length, providing new insights into potential risk factors for preterm birth.

In a collaboration between multiple labs and funded through March of Dimes, the investigators set out to map important gene regulatory regions and genetic markers relevant to preterm birth. Their first challenge was addressing the lack of functional genomics data in pregnancy-relevant tissue types.

"When you're studying a disease, there are typically a lot of genetic and tissue resources available in public databases," said co-senior author Carole Ober, PhD, Chair of Human Genetics at UChicago. "But pregnancy related conditions, like preterm birth, get much less attention or funding, and as a result pregnancy-relevant tissues are not well represented in those databases."

The paper, published on Dec. 2, 2020 in Science Advances, focused on decidualized cells derived from the endometrial cells attached to the placenta. Decidualized cells line the uterus during the latter half of the menstrual cycle, preparing it for implantation and supporting the growth and development of the placenta and fetus throughout pregnancy.

The investigators collected placental tissue donated by patients who had given birth and isolated the decidualized cells in the lab. Genetic analysis of these cells identified two new candidate preterm birth genes, HAND2 and GATA2.

"These genes are both important transcription factors that regulate the expression of several other genes," said co-first author Ivy Aneas, PhD, a research associate professor of human genetics at UChicago. "HAND2 mediates the effect of progesterone on the uterine epithelium while GATA2 is involved in stem cell maintenance."

Both of these processes and the genes that control them are known to be important for endometrial decidualization and embryo implantation.

"The fact that we identified a link between these two genes and the duration of gestation suggests that their roles in pregnancy may be more important than previously anticipated," said co-first author Noboru Sakabe, PhD, a staff scientist at UChicago.

Understanding how these genes contribute to the length of pregnancy could be a key to developing new preventions against preterm birth.

"Researchers have recognized a number of factors that can lead to preterm birth, ranging from environmental to infectious disease and beyond, but what is vexing is that we haven't been successful in preventing it," said co-senior author Marcelo Nobrega, MD, PhD, professor of human genetics at UChicago. "Our research took a look at the genetics and allowed us to pull out some links that might illuminate genetic pathways and signaling molecules involved in the decidualization process, which in turn might provide new targets for therapies."

The researchers were able to leverage combined expertise in human genetics, genomics and statistical analysis to combine data gathered from human endometrial cells in the lab with data from existing genome-wide association studies (GWAS) to zero in on key genetic variations that may be linked to preterm birth.

"Only six or seven genomic regions have been linked to preterm birth and gestational length," said co-senior author Xin He, PhD, assistant professor of human genetics at UChicago. "We don't know which genes are involved or how that influences cell function and risk of preterm birth. With our approach, we integrated genomics data generated from our center and integrated it with other databases to identify the underlying genetic interactions. This can lead us to genes that may be involved in this condition, which gives us a hint to the underlying biology."

While genetic factors are thought to play only a small role in the risk of preterm birth, the investigators were glad to see such clear results in their study.

"Preterm birth is so common, and some people experience it repeatedly," said Ober. "If you have a preterm birth, it doesn't matter if it's genetic or not, you just don't want to experience one again. We can now use this information to better understand some of the genetic component and how it plays a role in the condition."

Future research will investigate other kinds of cells that may play key roles in pregnancy and preterm birth, such as the immune cells that reside at the maternal-fetal interface, and grow the "roadmap" of genomic variations in endometrial cells by examining the effects of varied environmental conditions on gene expression.

The study, "Transcriptome and regulatory maps of decidua-derived stromal cells inform gene discovery in preterm birth," was supported by the March of Dimes Foundation. Additional authors include Nicholas Knoblauch, Debora R. Sobreira, Cristina Paz, Cynthia Horth, Ryan Ziffra, Harjot Kaur, Xiao Liu, Rebecca Anderson, Jean Morrison, Sarosh Rana, and Vincent J. Lynch at the University of Chicago; Nicole Clark, Chad Grotegut, Timothy E. Reddy, Amy Murtha, and Gregory E. Crawford at Duke University; Virginia C. Cheung, John Kessler, and William Grobman at Northwestern University; Bo Jacobsson at the University of Gotenberg; Mikko Hallman at Olu University Hospital; Kari Teramo at Helsinki University Central Hospital and University of Helskinki; and Ge Zhang and Louis J. Muglia at Cincinnati Children's Hospital Medical Center.