Culture

An international research team led by Professor Charles Gauthier from the Institut national de la recherche scientifique (INRS) has discovered a new molecule with potential to revolutionize the biosurfactant market. The team's findings have been published in Chemical Science, the Royal Society of Chemistry's flagship journal.

Surfactants are synthesized from petroleum and are the main active ingredient in most soaps, detergents, and shampoos. Biosurfactants, produced by bacteria, are safer and can replace synthetic surfactants.

Rhamnolipid molecules are some of the safest surfactants known and are particularly attractive, thanks to their biodegradability, minimal toxicity, and amenability to be produced from industrial waste. But there's a problem. They are made using Pseudomonas aeruginosa, a pathogenic bacterium harmful to humans.

"If we want to fully gain the benefits of rhamnolipids, we need to grow these pathogenic bacteria on a huge scale. And because that's a health risk, the industry is looking for alternatives," explained Professor Gauthier. The molecules produced by these bacteria are usually mixed with other compounds or virulence factors, making them trickier to use.

To address the problem, the research team identified molecules that resemble rhamnolipids in Pantoea ananatis, a non-pathogenic bacterium. The team was then able to chemically synthesize these molecules, called ananatosides, in the laboratory, raising the possibility that they could be produced on a larger scale than using bacteria. The industry is already showing interest in these promising new biosurfactants.

A look at the structure

The new molecule comes in two different forms, A and B. Ananatoside A structure is described as closed, while B is open. The molecule A is closed in on itself to form a loop. The process that closes the loop is called lactonization, and it has also been achieved with rhamnolipids to create new molecules.

The team has shown that the lactonized form has a large impact on the biological action of the molecules. It minimizes the surface-active properties of rhamnolipids and renders them toxic.

Now the researchers want to characterize further new biosurfactants and make the molecules more stable.

An interdisciplinary team

INRS professor Éric Déziel helped with the research as an expert on biosurfactants. His team produced and isolated ananatosides produced naturally from the bacteria Pantoea.

Mayri Alejandra Dìaz De Rienzo, a lecturer at the Liverpool John Moores University in England, also took part as an INRS guest professor. Her expertise in the fermentation and downstream processing of biosurfactants helped the team identify the surface-active properties of these new biosurfactants.

Maude Cloutier, a PhD student and recipient of a Vanier Canada Graduate Scholarship, and Marie-Joëlle Prévost, a recipient of a summer scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC), aided the team with their chemical synthesis work in the laboratory.

The nerve cells, also called neurons, in our brain control all the basic processes of our body. For this reason, there are different types of neurons distributed over specific regions of the brain. Researchers at the Max Planck Institute for Metabolic Research and the CECAD Cluster of Excellence in Aging Research of the University of Cologne have developed an approach that allows them to show that neurons that are supposedly the same are actually very different: they not only sense different hormones for the body's energy state, but also have a different influence on food intake. This can have a direct effect on our metabolism, for example by differentially restraining our appetite.

The brain processes our sensory perceptions, controls our behaviour and stores our memories. Because of these many functions, different types of nerve cells with specific tasks exist in different regions of our brain. One such type of nerve cells are the so-called POMC neurons, which play an important role in the metabolism of our body. "POMC neurons are critically involved in the control of appetite, energy expenditure and metabolism," explains Nasim Biglari, a recently graduated PhD and first author of the study. "In recent years, it has been increasingly confirmed that POMC neurons are more diverse than previously thought." Such differences result, for example, from a different response to hormones secreted by the body and are only noticeable when individual POMC neurons are compared with each other. In such a case, scientists refer to different subtypes of neurons. "Whether the different subtypes also play a different role in metabolism has not been clarified so far," says Nasim Biglari.

Same nerve cell - different influence on food intake

"We have now succeeded in making different subtypes of neurons visible in mice at the genetic level and thus were able to subject them to more detailed investigation", says Nasim Biglari. "Using this new, genetic approach, we were able to describe two different subtypes of POMC neurons in detail for the first time. For example, our results show a different distribution of the two subtypes within the same specific brain region. Moreover, they sense different hormones for the body's energy state. The two subtypes even act differently on food intake, with one part of the POMC neurons suppressing appetite more potently than the other." Because of the influence of POMC neurons on metabolism and food intake, these observations could also be relevant to diseases such as obesity and diabetes.

"We were able to show for the first time that the diversity of POMC neurons is important for their function in the control of metabolism. In further experiments, we would like to increasingly address the questions of how the two subtypes of POMC neurons influence metabolism in detail and which neuronal circuits in the brain they engage to carry out their effects", Nasim Biglari is looking forward to future experiments. "More generally, however, the approach we have developed can also be used to identify cell subtypes in other organs and for other types of cells. This could lead to many more insights into the diversity of our body's cells."

For young plants, timing is just about everything. Now, scientists have found that herbivores, animals that consume plants, have a lot to say about evolution at this vulnerable life stage.

Once a plant seedling breaches the soil surface and begins to grow, a broad range of factors will determine whether it thrives or perishes.

Scientists have long perceived that natural selection favors early rising seeds. Seedlings that emerge early in the growing season should have a competitive advantage in monopolizing precious soil resources. Early growth also should mean more access to light, since early growers can block sunlight for seedlings that emerge later in the season.

Despite plenty of proof that germinating early is highly advantageous, many plants germinate later. Why?

University of California San Diego researchers found in a recent study that herbivores have a lot to say in determining how germination time contributes to plant growth.

Research published in the journal Evolution Letters by former UC San Diego graduate student Joseph Waterton and Division of Biological Sciences Professor Elsa Cleland has shown that certain vertebrate herbivores--including mice, rabbits and birds--play an underappreciated role in shaping natural selection in plant growth. Due to earlier seasonal growth patterns emerging from climate change, the new findings may factor into evolutionary responses to global environmental changes.

"Germination timing is a really important trait that influences the fitness of plants and their ability to survive and reproduce," said Waterton, who received his PhD in Biological Sciences and is now at Indiana University. "Until this study we didn't understand the role herbivores played in the evolution of this trait--we had very little idea of what shaped this trait besides aspects of the abiotic environment, such as climate."

In field studies using two California grass species, Waterton and Cleland found that early emerging seedlings were more impacted by vertebrate herbivores compared to those that emerged later, likely because they were the first and biggest bits of greenery available on the landscape at the start of the growing season when not much else was growing. They found that such early season consumption by herbivores shrinks the benefit of early seedling emergence.

Conducted at the UC San Diego Biology Field Station in early 2018, the researchers' study examined native Stipa pulchra and non?native Bromus diandrus grasses, common California grass species with vastly different origins and growth strategies, in neighboring plots that either excluded or allowed access to vertebrate herbivores. Herbivores consistently weakened the success of early emergers in both grass species, the results showed.

With climate change forces shifting the timing of many plant life stages earlier in the year, the new study shows that herbivores are likely working as a counteracting force.

"Plants that germinate earlier than their neighbors tend to win out. But our study shows that herbivory early in the growing season can counteract the advantage of early germination," said Cleland, a professor in the Ecology, Behavior and Evolution Section. "This is important because in order to persist and keep pace with climate change, many species will need to shift their seasonal timing. Our study shows that we can't accurately estimate the strength of natural selection on key traits if we don't account for realistic forces acting in nature, such as herbivory on plants."

No matter one's age, race, gender, socioeconomic status or political party, COVID-19 has impacted everyone at some level. That impact has been especially palpable for the approximately 1.3 million elderly Americans who reside in the country's 15,600 nursing homes.

Inside these facilities, the forced isolation caused by COVID-19 disrupted daily routines and left many of the residents with higher-then-normal levels of stress, anxiety and depression. Because many of these elderly individuals lack the resources or knowledge to use communications tools such as FaceTime or Zoom, their family and friends had no way to visit them except through a facility window.

What these family members couldn't see as they peered through their loved one's glass frame was the mental toll the pandemic was taking on the facility's health care staff.

To better understand this toll, Ashish Sarangi, M.D., recently conducted research into the mental health consequences of COVID-19 geriatric care in a nursing home setting. His research, "A Descriptive Study Evaluating the Impact of COVID-19 on Delivery of Care and Mental Health of Geriatric Nursing Home Staff," was published in the April issue of the American Journal of Geriatric Psychiatry. The study also was presented in March during the honors alumni session at the American Association of Geriatric Psychiatry's annual meeting.

Sarangi, co-chief psychiatry resident at the Texas Tech University Health Sciences Center (TTUHSC) School of Medicine, conducted his research at a nursing home facility in Lubbock, Texas using an online survey that was distributed to staff physicians, registered nurses and LVNs.

"What we found is that there was a lot of mental health impact on the staff members, and the reasons were anywhere from working through optimally long hours to they didn't have enough PPE (personal protective equipment) available," Sarangi said. "They're fearful of contracting COVID and taking it home to their families and there was just, overall, a lot of stress and negative mood as well."

Many of the facility's staff members did indeed contract COVID-19, requiring them to quarantine at home while others worked extended shifts to cover the time missed. The stress of working longer shifts was compounded by the lack of PPE.

"That was very challenging for them," Sarangi said. "Also, there were no visitors allowed either for the patients or staff members. It was pretty much a lockdown facility for 10 to 12 hours a day and they didn't have any kind of mental support; there was no counseling or anything like that going on."

The facility employed telemedicine and other electronic platforms to help offset staff concerns about contracting the virus and ease the sense of isolation among staff and residents. However, Sarangi said, many residents and staff found the use of technology unhelpful. Most residents simply weren't able to successfully navigate the platforms and staff found that it added to their sanitation burden. The more equipment the technology required, the more time they had to spend sanitizing it before its next use.

In addition, the same stress that was causing mental health issues for staff and residents also was affecting their physical health. Sarangi said this is important because stress, no matter its source, can predispose people to cardiovascular conditions such as heart attacks and strokes.

"Even if you're perfectly healthy or don't have any pre-existing conditions, stress can also lead to diabetes and actually increase your risk for infections like COVID-19," Sarangi added. "And if you are chronically stressed, it can affect your immune system and predispose you to COVID-19 as well."

The availability of vaccines have eased some of the stress related to COVID-19, but Sarangi said staff still work under a cloud of fear that will likely remain until the pandemic ends. They worry every day about whether they've contracted the disease, or worse, passed it on to a family member at home or to an elderly nursing home resident.

"It's like walking into a fire sometimes because some of these long-term care facilities, at least in the heat of the pandemic, they were pretty much hotspots for COVID-19," Sarangi emphasized. "It's something that we don't really think about in Lubbock, but it also happens here a lot. We still have a lot of nursing homes and long-term care facilities here and I think they need the mental health support; they need resources. I think that would be the main take-home point of this study."

VANCOUVER, Wash. - Employer COVID-19 safety measures influenced worker precautions even when they were not on the clock, according to a new study out of Washington State University.

The study found that workplace cultures that adopted COVID-19 prevention measures, such as daily health checks and encouraging sick workers to stay home, resulted in less "sickness presenteeism" or going places when feeling ill. The effect was found both inside and outside of work - meaning fewer employees with COVID-19 symptoms showed up to work and other public places like grocery stores, gyms and restaurants.

The same held true for attitudes toward the COVID-19 prevention measures recommended by the Centers for Disease Control and Prevention such as mask wearing and social distancing: employees working for companies with strong COVID-19 prevention measures were more likely to have positive attitudes toward the CDC guidelines.

"The workplace COVID-19 climate had a direct effect on shaping employee attitudes towards the personal, preventative health actions that the CDC recommends," said Tahira Probst, WSU psychology professor and lead author of the study published in the Journal of Occupational and Environmental Medicine. "Public health officials and employers should be aware of the impact that organizations and workplaces can have on stemming the tide of the pandemic. It's not just that employers have an impact on transmission that occurs within the workplace, but they are also influencing those same employees' attitudes and behaviors outside of the workplace."

For the study, the researchers surveyed more than 300 working adults recruited on the Amazon Mechanical Turk crowdsourcing website in three waves during the pandemic holiday surge. They first surveyed the workers in October 2020 to assess the COVID-19 climate of their workplaces; then in December 2020, about their attitudes toward the CDC prevention guidelines, and finally in February 2021, about their work and non-work behaviors when sick or exposed to COVID-19.

The study found a significant connection between the workplace COVID-19 climate, employee attitudes toward the pandemic prevention measures, and ultimately whether they showed up to work or other public places while feeling ill with COVID-19 symptoms or following known exposure to the virus.

The respondents came from 44 U.S. states and Washington D.C. While the survey did not use a nationally representative sample, the respondents' demographics--with a median age of 40, 59% male and 76% white--aligned well with the general labor force with a median age of 40-44, 53% male and 78% white. However, the survey group was generally more highly educated with 67% reporting having a college degree or higher, compared to 40% in the general labor force.

During the survey period, about half of the respondents were working onsite and half remotely. Interestingly, the study found that even the remote workers were influenced by their employers' COVID-19 workplace climate. Remote workers were less likely to frequent public spaces after exposure to the virus or while ill when working for a company with strong prevention measures in place.

The researchers noted that the many U.S. organizations have long-standing cultures stigmatizing sick leave and encouraging sickness presenteeism. The good news, the authors point out, is that workplaces can help curb the spread of COVID-19 by actively encouraging sick employees to stay home, instituting daily health checks, and adopting other CDC workplace health and safety precautions.

The pandemic has forced some organizations to examine their culture around sick leave, and Probst is interested to see if this will become a long-term change.

"One of the more enduring consequences of the pandemic might be that organizations not only offer more sick leave but also encourage employees to stay home if they're sick," said Probst. "Frankly, prior to COVID-19, a lot of our culture has been: 'unless you're gravely ill and can't get out of bed, you should be at work.' That behavior spreads diseases and ultimately reduces productivity. We're hopeful that the pandemic might institute a re-thinking of this norm moving forward."

Researchers from Case Western Reserve University have identified a potential new approach to better controlling epileptic seizures.

Lin Mei, professor and chair of the Department of Neurosciences at the Case Western Reserve School of Medicine, who led the new study in mouse models, said the team found a new chemical reaction that could help control epileptic seizures.

Their findings were recently published in The Journal of Clinical Investigation.

Epilepsy is a neurological disorder in which abnormal brain activity causes seizures or periods of unusual behavior, sensations and sometimes loss of awareness.

A human brain contains about 86 billion nerve cells, also known as neurons. Eighty percent of them--known as excitatory neurons--send messages to bundles of nerves that control muscles, typically calling on them to do something. In a healthy brain, activity that excitatory neurons inspire is managed by the remaining 20% of nerve cells, called inhibitory neurons.

"This balance between excitatory and inhibitory neurons is absolutely important for everything that we do,'' Mei said. "When the balance is tilted, so that excitatory neurons are super active, there will be a problem. It's highly likely there will be epilepsy.''

Two mechanisms cause epilepsy: One is genetic; the other is environmental.

In Dravet syndrome, a genetic type of epilepsy that is among the more severe forms of the condition, the sodium channel--a membrane pore critical for inhibiting neuron activation--is mutated and allows excitatory neurons to misfire, causing seizures.

"It would be great if you could find a mechanism to make the sodium channels more stable,'' Mei said.

He and his colleagues found that a chemical reaction in the brain, called neddylation, stabilizes the sodium channel in mouse models. When the researchers produced a mouse that lacked the protein required for neddylation in inhibitory neurons, it developed epilepsy. The surprising emergence of the condition inspired the team to explore the neddylation process in more depth; eventually they discovered that neddylation plays a critical role of for the sodium channel.

"If we have that chemical reaction in check," he said, "you could help control epilepsy.''

Mei said the research provided evidence that a mutation in patients with epilepsy had a problem with neddylation, suggesting "neddylation theory" may apply to human patients.

The next step in their research, he said, is to identify drugs or approaches that can manipulate this chemical reaction to stabilize the sodium channel. The researchers are also conducting further experiments to determine whether this applies to patients with other types of epilepsy, not just Dravet patients.

"Our finding that neddylation can prevent epilepsy in mouse models represents a new direction for future research," he said. "With this new lead, scientists or pharmaceutical companies can look for chemicals to boost neddylation. The concept is still in an early stage and much needs to be done to make a difference for patients."

This chemical reaction--neddylation--has also been considered a target for cancer research, Mei said, so it could have applications beyond epilepsy.

Researchers have developed a tool to help governments and other organizations with limited budgets spend money on building repairs more wisely.

The new tool uses artificial intelligence (AI) and text mining techniques to analyze written inspection reports and determine which work is most urgently needed.

"Those assessments are now largely subjective, the opinions of people based on experience and training," said Kareem Mostafa, an engineering PhD student at the University of Waterloo who led the project. "We're using actual data on buildings to make spending decisions more objective."

Researchers looked at inspection reports on the roofs of 400 schools managed by the Toronto District School Board. A computer model was developed to search the one- to two-page reports for about 30 keywords, including words such as 'damage' and 'leaks.'

By analyzing the frequency of the keywords, plus factors including the age of roofs, the AI software divided the schools into four categories based on the urgency of repair or replacement. The goal was to give the school board an objective way to target its limited funds, speeding up the assessment process and helping it spend money where it makes the most sense.

"We're playing Moneyball with building assets," Mostafa said. "By using data on buildings instead of opinions, our model also takes potential political headaches out of the process."

Although the software was developed to assess the need for roof repairs, it can be tweaked to help prioritize other kinds of work for organizations with budget limitations and many buildings to maintain.

Mostafa is also working to incorporate other kinds of data, including AI analysis of photographs, into the assessment model.

Tarek Hegazy, a professor of civil and environmental engineering at Waterloo, and Ahmed Attalla, a project manager with the school board, collaborated on the study.

AURORA, Colo. (May 6, 2021) - Scientists examining the remains of 36 bubonic plague victims from a 16th century mass grave in Germany have found the first evidence that evolutionary adaptive processes, driven by the disease, may have conferred immunity on later generations of people from the region.

"We found that innate immune markers increased in frequency in modern people from the town compared to plague victims," said the study's joint-senior author Paul Norman, PhD, associate professor in the Division of Personalized Medicine at the University of Colorado School of Medicine. "This suggests these markers might have evolved to resist the plague."

The study, done in conjunction with the Max Planck Institute in Germany, was published online Thursday in the journal Molecular Biology and Evolution.

The researchers collected DNA samples from the inner ear bones of individuals in a mass grave in the southern German city of Ellwangen which experienced bubonic plague outbreaks in the 16th and 17th centuries. Then they took DNA samples from 50 current residents of the town.

They compared their frequency spectra - the distribution of gene variants in a given sample - for a large panel of immunity-related genes.

Among the current inhabitants, the team found evidence that a pathogen, likely Yersinia pestis which causes bubonic plague, prompted changes in the allele distribution for two innate pattern-recognition receptors and four Human Leukocyte Antigen molecules, which help initiate and direct immune response to infection. An allele is a variant form of a gene.

"We propose that these frequency changes could have resulted from Y.pestis plague exposure during the 16th century," Norman said.

The findings are the first evidence that evolutionary processes, prompted by Y. pestis, may have been shaping certain human immunity-relevant genes in Ellwangen and possibly throughout Europe for generations.

And since the plague tormented Europe for nearly 5,000 years, the study suggests that these immunity genes may have been pre-selected in the population long ago but recently became selected through epidemic events.

"Although the lethality of the plague is very high without treatment it remains likely that specific individuals are protected from, or more susceptible to, severe disease through polymorphism in the determinants of natural immunity," the study said. "In this case, any change in allele frequencies that occurred during a given epidemic crisis could be evident as genetic adaptation and detectable in modern day individuals."

Later simulations showed that natural selection likely drove these allele frequency changes.

"I think this study shows that we can focus on these same families of genes in looking at immunity in modern pandemics," Norman said. "We know these genes were heavily involved in driving resistance to infections."

The study also demonstrates that, so far, no matter how deadly the pandemic there are always survivors.

"It sheds light on our own evolution," Norman said. "There will always be people who have some resistance. They just don't get sick and die and the human population bounces back."

Still, he doesn't want people to get the wrong message, especially in the era of Covid-19.

"I wouldn't want to discourage anyone from taking a vaccine for the current pandemic," Norman said. "It's a much safer bet than counting on your genes to save you."

Monash University researchers have engineered new antimicrobial surfaces that can significantly reduce the formation of bacteria on medical instruments, such as urinary catheters, and reduce the risk of patient infection while in hospital.

This world-first study demonstrates the potential for 3D engineered surfaces in preventing the initial formation of microcolonies of Escherichiacoli (E.coli), Klebsiellapneumoniae and Pseudomonas aeruginosa - the three most common urinary tract bacterial infections (UTIs) associated with catheters.

The study team, led by Dr Victor Cadarso, from Monash University's Department of Mechanical and Aerospace Engineering and the Centre to Impact AMR, engineered surfaces with smooth, 3D micro features, instead of the traditional sharp cross-sectional ones, to reduce the potential for harmful bacteria to attach on these surfaces in large numbers.

The tested surfaces demonstrated reduction in both attachment of bacteria and biofilm formation. One of the surfaces, P01, presented excellent properties against E.coli, K.pneumoniae, and P. aeruginosa with 55 per cent, 69 per cent and 68 per cent less bacterial cells attached, and 53 per cent, 77 per cent and 66 per cent less microcolonies being formed, respectively.

Urinary tract infections (UTIs), associated with urinary catheters, are the most common type of healthcare-associated infections. They have been identified by the World Health Organization (WHO) as an urgent global health threat.

Approximately one in five of hospitalised patients globally are administered urinary catheters during their hospital stay. It is estimated that 13,000 people across the world die each year from UTIs, and a further 700,000 die from associated antimicrobial resistance infections because of the resistance of superbugs to antibiotics and current sterilisation methods.

The study was published in the international journal ACS Applied Materials & Interfaces. Researchers from Monash University's Department of Microbiology were also involved and part of the work was done at the Melbourne Centre for Nanofabrication.

"Using E.coli as an example, we found bacterial cells that form on surfaces do so mostly on the sharp corners. By removing these sharp features, the bacteria can no longer colonise the surface as effectively. This same effect has been demonstrated for the two other pathogens in this study," said Sara Ghavamian, from the Monash Department of Mechanical and Aerospace Engineering, who created these surfaces.

"High-touch surfaces within hospitals, such as catheters and ventilators, are a significant source of microbial spread and healthcare-associated infections.

"Infection control through physically altering the micro architecture of these surfaces, rather than the traditional use of chemical agents, is not only a more durable approach but also an effective strategy for combating antimicrobial resistance."

The bacterial colonisation of surfaces takes place over time. Once bacteria attach to a surface, a series of cellular responses are triggered. After this initial phase, including a few rounds of cell division by this bacteria, microcolonies of hundreds of bacterial cells are formed.

After successful colonisation, the bacteria form a biofilm - a large population of bacteria in a 'secreted cellular matrix' that binds together and protects the cells from antibiotics and the immune system. This might create a superbug that can cause long-term health implications for patients.

Researchers demonstrated that their 3D engineered microtopographies with varying heights and smooth curved cross-sections can simultaneously deter both the initial attachment and the formation of biofilms for three clinically relevant bacteria.

Through an extensive screening process, researchers identified that the sharp corners of the vertical side walls within the conventional micropatterned surfaces gifted bacteria with perfect hiding spots to shelter themselves against the flow of fluids which could wash them away.

The researchers hypothesise that by smoothing out these corners, the bacteria would be left with nowhere to hide.

"After equivalent incubation periods with the same bacteria, we discovered that while the micropatterned surfaces were indeed successful in reducing the number of microcolonies formed they, problematically, increased the number of attached bacteria compared with traditional micro-flat surfaces," Sara said.

"Opposite the conventional sharp micropatterned surfaces, our smooth design demonstrated a simultaneous decrease in both the number of bacterial attachment and microcolony formation compared to the standard flat surfaces.

"Developing strategies to prevent the bacterial colonisation of surfaces, such as catheters, without requiring antimicrobial drugs or chemicals is critical to stop biofilm formation and the potential spread of harmful diseases."

A new survey study suggests that, for adolescents who received unplanned distance education due to the COVID-19 pandemic, experiencing one's own competence was linked to positive emotion, self-motivation to learn, and pro-learning behaviors. Feeling connected to others was also linked to positive emotion. Julia Holzer of the University of Vienna, Austria, and colleagues present these findings in the open-access journal PLOS ONE.

The new research draws on a psychological theory known as self-determination theory, which outlines three basic psychological needs for well-being: autonomy, connection to others, and experiencing one's own competence. Previous research has provided much evidence in support of this theory, but it was previously unclear how it applies to adolescents receiving distance education, which poses risks for well-being and learning.

To explore self-determination theory in the context of distance education, Holzer and colleagues conducted a survey study of 25,305 adolescents from eight countries in Europe, Asia, and North America. The survey ran from April to June 2020 and included questions about the three basic psychological needs, well-being, and learning behaviors. Links between these factors were uncovered by statistical mediation analyses of the survey data.

Across all eight countries, experiencing one's own competence--for example, being able to complete most of one's schoolwork--was linked to positive emotion, self-driven motivation to learn, and active learning behavior in the form of engagement and persistence. Perceived connectedness to others was also consistently linked to positive emotion. These findings were in line with the researchers' initial hypotheses.

Additional connections were found between the basic needs, well-being, and learning behaviors, but these were less consistent between countries. Additionally, contrary to initial hypotheses, adolescents' perceived autonomy was not strongly linked to positive emotion or motivation to learn.

Together, these findings could help inform the design of distance education programs, such as by incorporating ways to promote feelings of connection to others, or providing regular feedback and opportunities for improvement to promote experiences of competence. Further research could also help confirm or expand on these results.

The authors add: "Given the risks and challenges of the COVID-19 pandemic for adolesecents, the present research identifies characteristics that relate to adolescents' psychological well-being and learning quality during the pandemic. The sample encompasses students from altogether eight countries in Europe, Asia and North America, thus enabling to derive common conclusions applicable across different cultural contexts."

Almost 1 in 4 COVID-19 patients have another bacterial, viral or fungal infection simultaneously or subsequently, with such patients experiencing worse disease outcomes.

Tsukuba, Japan - Autoimmune diseases occur when an individual's immune system fights their own body as if it was a foreign invader. However, in healthy people, these responses are prevented by a process known as immune tolerance. Many complex biological mechanisms maintain the necessary balance between immune activation and suppression to ensure immune tolerance does not prevent the body from effectively fighting pathogens.

In a new study published in PNAS, a group of researchers from the University of Tsukuba uncovered how the relationship between two receptors called DNAM-1 and TIGIT helps preserve the balance for optimal immune function. Both of these molecules have previously been studied in a subset of immune cells called regulatory T cells, or Tregs.

Tregs are crucial mediators of immune tolerance and autoimmunity prevention. Treg activity is typically inhibited during inflammatory reactions to infection to allow the body to efficiently fight and clear the invader. However, the molecular mechanisms that control this balance in Treg behavior are not fully understood. When a specific activating molecule (CD155) binds to the receptors DNAM-1 and TIGIT, they trigger signals that tell the T cells how to behave and what functions to perform.

The Tsukuba team found that DNAM-1 and TGIT compete for CD155 under inflammatory conditions. When CD155 binds to DNAM-1, this receptor sends messages that tell the immune system to wake up and activate. However, when CD155 binds to TIGIT, this receptor acts the opposite way and suppresses the immune system, thereby telling the T cells to stop activating.

To investigate the molecular interplay between DNAM-1 and TIGIT, the researchers studied mice (an acute graft-versus-host disease mouse model) infused with either Tregs lacking DNAM-1 or normal Tregs. "We found that the absence of DNAM-1 resulted in enhanced TIGIT-mediated signaling. This shift in balance occurs because more CD155 is available to bind to TIGIT when DNAM-1 is not present. This help the Tregs maintain immune suppression during periods of inflammation," explains Professor Kazuko Shibuya, senior author of the study. "We observed similar dynamics in a humanized mouse model, supporting the relevance of these findings to humans." In short, this mechanism helps tell the Tregs to not block the immune system when a true danger is lurking.

Given that Tregs play an important role in autoimmune diseases, the results suggest that the balance between DNAM-1 and TIGIT may be improperly regulated in individuals suffering from autoimmunity. This potential disease mechanism will be the focus of future research. These findings in mice suggest DNAM-1 could be used as a novel molecular target for treating autoimmune diseases.

Recently published in the scientific journal Brain Communications, a new study distinguished structural patterns between individuals with corpus callosum dysgenesis (CCD), a congenital condition that consists of the absence or incomplete development in the connecting structure between the two brain hemispheres. The research was carried out by the D'Or Institute for Research and Education (IDOR), the University of Pittsburgh, Oswaldo Cruz Foundation (Fiocruz), and the Federal University of Rio de Janeiro (UFRJ).

Investigating CCD is an arduous task for doctors and neuroscientists. There aren't many patients available for research, and the anatomical variability of brains with CCD creates a broad clinical spectrum. Due to brain plasticity - the organ's ability to create alternative connections to ensure its functioning in adverse situations -, the clinical scenario range from the complete lack of symptoms to epilepsy and psychomotor retardation, in addition to being commonly found in autism spectrum disorder. "The CCD is one of the greatest mysteries of neuroscience. To this day, researchers don't fully know how this neuroplasticity occurs. But we've had new discoveries in the past years, mainly through in vivo methods that analyze these patients' brain connections via imaging", informs the study's corresponding author, Dr. Fernanda Tovar-Moll, M.D., radiologist and president of IDOR.

Considering the challenges presented by this pathological plurality, the study's researchers analyzed the structural and neurological alterations of 11 patients with CCD, men and women aged from 4 to 33 years old. Of these, 6 had a complete absence of the corpus callosum (agenesis) and the other 5 were characterized by its hypoplasia, which is the underdevelopment of the structure.

The research was carried out through functional and structural magnetic resonance imaging. The images were first evaluated by a neuroradiologist to confirm the diagnosis of CCD and then were examined again to map the patients' neural connections, which were compared with a control group composed of 45 healthy individuals.

As expected, the results showed that structural connectivity in individuals with agenesis or hypoplasia of the corpus callosum differed from the images in the control group. However, clear differences were also noted within the groups with CCD. 

Despite having fewer connections when compared to the other two groups, patients with agenesis connected brain regions in a functionally similar way to healthy patients, while individuals with hypoplasia showed a broader, but abnormal and variant reorganization between brain connections, which would justify the worsening of symptoms in patients with this type of CCD. "The hypoplastic corpus callosum usually connects regions of the brain that it shouldn't connect. Instead of positive neuroplasticity, this characteristic could be the cause of symptoms", explains Diego Szczupak, Ph.D. and the study's first author.

Although previous studies have already described the anatomical heterogeneity in brains with CCD, the different types of dysgenesis have not yet been widely compared to each other, and the distinctions between their adaptive brain plasticity are still unfamiliar. These findings show that the hypoplasia and agenesis in CCD have unique fingerprints and use distinct plastic mechanisms to compensate for the partial or complete lack of the corpus callosum. But the authors emphasize that this does not necessarily mean that the coherence, speed, and precision of these connections reflect the same brain functioning as in healthy individuals.

Dr. Fernanda Tovar-Moll is also part of an international research consortium, the IRC5, whose mission is to discover the causes, consequences, and possible interventions for corpus callosum dysgenesis and associated brain connectivity disorders. From June 27th to July 2nd, IDOR is organizing an IRC5 meeting addressed to family members, doctors, neuroscientists, and psychologists interested in the topic. Information about the event will be available soon on the website http://www.idor.org and on IDOR's social networks.

Philadelphia, May 18, 2021 - Many socioeconomically disadvantaged children face poor cognitive and mental health outcomes, and researchers are working to determine the specific factors that link childhood conditions to those poor outcomes, including how they might shape brain circuitry. In a new study, researchers have examined how "neighborhood disadvantage" can affect the developing brain, including the brain's connectivity between regions.

The study appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, published by Elsevier.

Sarah Whittle, PhD, and Divyangana Rakesh, lead authors of the study, studied existing brain scans from 7,618 children aged 9-10 collected as part of the Adolescent Brain Cognitive Development (ABCD) Study. Previous studies have identified differences in some brain regions in disadvantaged children, but the current study used magnetic resonance imaging (MRI) to measure functional connectivity, or how well different regions of the brain are connected with one another, at rest.

Rather than considering a single measure of status such as household income, the new study classified children according to neighborhood disadvantage, which encompasses multiple risk factors such as pollution, crime, and access to lower-quality education and healthcare.

Dr. Whittle said the purpose of the study was to "inform us of the mechanisms through which disadvantage impacts children's development and functioning." The team also wanted to investigate the role of factors such as positive home and school environments that may help reduce the harmful effects of disadvantage.

Analysis of the brain scans revealed that, in children with higher scores reflecting greater disadvantage, functional connectivity was reduced both between and within several brain networks.

"Our findings suggest that growing up in a disadvantaged neighborhood indeed impacts the brain. Importantly, however, findings suggest that providing children with better home and school environments where they feel supported, receive positive feedback, and have opportunities to engage in different activities, can offset some of the negative effects of neighborhood disadvantage on children's brain development," Ms. Rakesh said.

The findings have policy implications in the context of designing interventions and policies targeted at youth and families exposed to disadvantage; they suggest a need to shift attention from a sole focus on family-level factors to community-level research and policies.

Cameron Carter, MD, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, said of the study, "These remarkable results show that improvements in the home and school environments can mitigate against the otherwise deleterious effects of growing up in a disadvantaged setting, providing a powerful message for the importance of public policies that provide more support at home and at school."

EUGENE, Ore. -- May 19, 2021 -- High-resolution imaging of fruit flies at the University of Oregon has captured mechanical motions that stem cells use to make neurons, the cells that make up the brain.

These motions coordinate cell division with differentiation, where newly born cells become neurons. Differentiation is essential for building the brain circuitry in complex organisms that underlies human cognition and emotions, said Ken Prehoda, a professor in the UO's Department of Chemistry and Biochemistry.

Prehoda was principal investigator of a project published online May 18 in the journal Cell Reports.

Drosophila fly brains have some 100,000 neurons, while human brains have more than 50 billion. Developmental research in Drosophila often leads to advances in human medicine.

The discovery, Prehoda said, suggests that the mechanical process is vital to understanding brain development and, potentially, for regenerating neurons and their connections following injuries.

"To make so many neurons, the developing brain acts like a factory with individual stem cell 'machines' continually producing neurons," Prehoda said. "We discovered that stem cells have more in common with real machines on a factory floor than previously appreciated in that they undergo a mechanical cycle when producing each neuron."

In the project, Bryce LaFoya, a postdoctoral researcher in the UO's Institute of Molecular Biology, used spinning-disk confocal microscopy to examine fruit fly brains with their stem cell membranes embedded with fluorescent markers. That unveiled the membrane dynamics of neural stem cells and their progeny at high resolution, revealing the mechanical cycle as each neuron was produced.

To make neurons, Prehoda said, neural stem cells must place special molecules, proteins called fate determinants, into one of two daughter cells that result from division. How that was done had been unclear despite many previous studies of physical interactions in which fate determinants are involved.

In a 2019 study in the journal eLife, Prehoda and Krystal Oon, a graduate student in the Institute of Molecular Biology, reported that proteins undergo movements along the membrane, but what drove the movement was known.

"Mechanical forces within the cell segregate components that are responsible for cellular identity after division," LaFoya said. "After the cell divides in two, because of these forces, one cell will remain a stem cell while the other will go on to become a neuron."

The cellular-scale mechanical forces revealed in the imagery were so strong that surrounding cell membranes became highly distorted before returning to normal, Prehoda added. Understanding the process from beginning to end, he said, could have implications for regenerative therapies.

"Our results indicate that the neuroblast membrane plays a role in polarity initiation and maintenance," LaFoya and Prehoda wrote in their conclusion, describing the process that the neural stem cells use to make neurons.