Earth

Antoine Champreux, a PhD student in the Global Ecology Lab at Flinders University, has catalogued the discovery of the new fern-like plant species as part of an international effort to examine the Australian fossil in greater detail.

The fossil was found in the 1960s by amateur geologist Mr John Irving, on the bank of the Manilla River in Barraba, New South Wales. The fossil was exposed after major flooding events in 1964, and Mr Irving gave the fossil to the geological survey of New South Wales, where it remained for more than 50 years without being studied.

It was dated from the end of the Late Devonian period, approximately 372-to-359 million years ago - a time when Australia was part of the Southern hemisphere super-continent Gondwana. Plants and animals had just started to colonise continents, and the first trees appeared. Yet while diverse fish species were in the oceans, continents had no flowering plants, no mammals, no dinosaurs, and the first plants had just acquired proper leaves and the earliest types of seeds.

Well-preserved fossils from this era are rare - elevating the significance of the Barraba plant fossil.

The fossil is currently in France, where Brigitte Meyer-Berthaud, an international expert studying the first plants on Earth, leads a team at the French laboratory of Botany and Modelling of Plant Architecture and Vegetation (AMAP) in Montpellier. This French laboratory is particularly interested in further examination of Australian fossils from the Devonian-Carboniferous geological period, to build a more detailed understanding of plant evolution during this era.

Mr Champreux studied the fern-like fossil during his master's degree internship at AMAP and completed writing his research paper during his current PhD studies at Flinders University.

"It's nothing much to look at - just a fossilised stick - but it's far more interesting once we cut it and had a look inside," says Mr Champreux. "The anatomy is preserved, meaning that we can still observe the walls of million-year-old cells. We compared the plant with other plants from the same period based on its anatomy only, which provide a lot of information."

He found that this plant represents a new species, and even a new genus of plant, sharing some similarities with modern ferns and horsetails.

"It is an extraordinary discovery, since such exquisitely-preserved fossils from this period are extremely rare," he says. "We named the genus Keraphyton (like the horn plant in Greek), and the species Keraphyton mawsoniae, in honour of our partner Professor Ruth Mawson, a distinguished Australian palaeontologist who died in 2019."

An article describing the new plant - Keraphyton gen. nov., a new Late Devonian fern-like plant from Australia, by A Champreux, B Meyer-Berthaud and A-L Decombeix - has been published in the scientific journal PeerJ and It reinforces the partnership between the lab AMAP (Montpellier, France) and Flinders University.

Research out today identifies traits among high-risk adolescents associated with increased risk for gun use. Among high-risk adolescents, those with greater callous-unemotional traits were more likely to carry a gun and to use a gun during a crime over a four-year period following an initial arrest, according to a study published online in the American Journal of Psychiatry.

Callous-unemotional traits refer to individuals with limited guilt, reduced empathy, reduced displays of appropriate emotion, and a lack of concern over performance in important activities. An estimated 25% - 30% of adolescents with serious conduct problems have callous-unemotional traits and they have more persistent and severe aggression and worse treatment outcomes than adolescents without callous-unemotional traits.

Gun violence is a serious public health concern in the U.S. and reducing gun violence by youth is of particular concern. Nearly 40,000 people in the U.S. died of gun-related violence in 2018, according to the Centers for Disease Control and Prevention (CDC). Approximately 30% of gun-related homicides were committed by adolescents and young adults ages 12-24.

The study, led by researchers at the Louisiana State University, involved more than 1,200 high-risk adolescents, or male juvenile offenders from three regions of the U.S. They were assessed after their first arrest and then reassessed every six months for three years and at four years. Callous-unemotional traits were measured through a standardized self-report inventory after the first arrest. The use of a gun during a crime and peer gun carrying and ownership were self-reported.

After accounting for other factors (such as lifetime offending, impulse control, parental monitoring and exposure to violence) the study found teens with greater callous-unemotional traits were more likely to carry a gun and to use a gun during a crime in the four years after their initial arrest. Lead author Emily L. Robertson, M.A, and colleagues also found that the teens with greater callous-unemotional traits were less likely to be influenced by their peers owning/carrying guns compared to teens with less callous-unemotional traits, suggesting the known influence of peer gun carrying and ownership may have been underestimated
in past research.

The authors conclude that "callous-unemotional traits predicted increased frequency of gun carrying and a higher likelihood of using a gun in a violent crime." They note, however, callous-unemotional traits were not as strong of a predictor of carrying a gun as other risk factors (such as lifetime offending and exposure to violence).

Yale scientists may have found a cause for the sudden onset of obsessive-compulsive disorder (OCD) in some children, they report.

Pediatric autoimmune neuropsychiatric disorders, or PANDAS, were first proposed in the 1990s. Thought to be triggered by streptococcal infections, they account for an unknown portion of youth OCD cases. But the biology underpinning this disorder has baffled scientists.

The new Yale research, published June 16 in the American Journal of Psychiatry, identifies antibodies that bind to particular brain cells called interneurons as an explanation.

"It is really OCD plus," said senior author Christopher Pittenger, assistant chair for translational research, associate professor of psychiatry and a researcher in the Yale Child Study Center. "These children have OCD, but they can also have severe separation anxiety, subtle motor symptoms, and show frequent need to urinate. Many refuse to eat."

While 1% to 3% of children will be diagnosed with OCD by the age of 17, the fraction of OCD cases that can be attributed to PANDAS is unknown. Some doctors say there is not enough evidence to support PANDAS as a distinct diagnosis from OCD. Others, including many parents of children with the syndrome, argue it may account for a large subset of children with OCD.

Pittenger and his team decided to explore the biology of the disorder in a series of experiments involving 27 children who met the strictest criteria for a PANDAS diagnosis and 23 control subjects.

They found that many children with a PANDAS diagnosis possess high levels of an antibody that can attack specific interneurons -- neurons that modify the signaling of other nearby cells. These antibodies are concentrated in the striatum, an area of the brain that is associated with voluntary motor control, among other functions, and is known to be involved in OCD. When the antibody binds to these neurons, it reduces their activity.

PANDAS is "real, but probably rare," Pittenger said.

Adults with Tourette syndrome, a related syndrome characterized by vocal and motor tics, lack the same specific striatal interneurons, suggesting that problems with these cells may play a role in several conditions, Pittenger noted.

His lab aims to explore this biology in other children with OCD and Tourette syndrome to see how widespread interneuron-binding antibodies are in this group of related conditions.

In 2017, Stanford University researchers presented a new device that mimics the brain's efficient and low-energy neural learning process. It was an artificial version of a synapse - the gap across which neurotransmitters travel to communicate between neurons - made from organic materials. In 2019, the researchers assembled nine of their artificial synapses together in an array, showing that they could be simultaneously programmed to mimic the parallel operation of the brain.

Now, in a paper published June 15 in Nature Materials, they have tested the first biohybrid version of their artificial synapse and demonstrated that it can communicate with living cells. Future technologies stemming from this device could function by responding directly to chemical signals from the brain. The research was conducted in collaboration with researchers at Istituto Italiano di Tecnologia (Italian Institute of Technology – IIT) in Italy and at Eindhoven University of Technology (Netherlands).

"This paper really highlights the unique strength of the materials that we use in being able to interact with living matter," said Alberto Salleo, professor of materials science and engineering at Stanford and co-senior author of the paper. "The cells are happy sitting on the soft polymer. But the compatibility goes deeper: These materials work with the same molecules neurons use naturally."

While other brain-integrated devices require an electrical signal to detect and process the brain's messages, the communications between this device and living cells occur through electrochemistry - as though the material were just another neuron receiving messages from its neighbor.

How neurons learn

The biohybrid artificial synapse consists of two soft polymer electrodes, separated by a trench filled with electrolyte solution - which plays the part of the synaptic cleft that separates communicating neurons in the brain. When living cells are placed on top of one electrode, neurotransmitters that those cells release can react with that electrode to produce ions. Those ions travel across the trench to the second electrode and modulate the conductive state of this electrode. Some of that change is preserved, simulating the learning process occurring in nature.

"In a biological synapse, essentially everything is controlled by chemical interactions at the synaptic junction. Whenever the cells communicate with one another, they're using chemistry," said Scott Keene, a graduate student at Stanford and co-lead author of the paper. "Being able to interact with the brain's natural chemistry gives the device added utility."

This process mimics the same kind of learning seen in biological synapses, which is highly efficient in terms of energy because computing and memory storage happen in one action. In more traditional computer systems, the data is processed first and then later moved to storage.

To test their device, the researchers used rat neuroendocrine cells that release the neurotransmitter dopamine. Before they ran their experiment, they were unsure how the dopamine would interact with their material - but they saw a permanent change in the state of their device upon the first reaction.

"We knew the reaction is irreversible, so it makes sense that it would cause a permanent change in the device's conductive state," said Keene. "But, it was hard to know whether we'd achieve the outcome we predicted on paper until we saw it happen in the lab. That was when we realized the potential this has for emulating the long-term learning process of a synapse."

A first step

This biohybrid design is in such early stages that the main focus of the current research was simply to make it work.

"It's a demonstration that this communication melding chemistry and electricity is possible," said Salleo. "You could say it's a first step toward a brain-machine interface, but it's a tiny, tiny very first step."

Now that the researchers have successfully tested their design, they are figuring out the best paths for future research, which could include work on brain-inspired computers, brain-machine interfaces, medical devices or new research tools for neuroscience. Already, they are working on how to make the device function better in more complex biological settings that contain different kinds of cells and neurotransmitters.

Pathological protein clumps are characteristic of a series of diseases, such as Alzheimer's disease, Parkinson's disease, and type 2 diabetes. Scientists at Forschungszentrum Jülich, Heinrich Heine University Düsseldorf, and Maastricht University have now used cryo-electron microscopy to obtain a sharp image for the first time of how individual molecules are arranged in protein strings, which constitute the deposits typical for diabetes. The structure of the fibrils is very similar to that of Alzheimer's fibrils. These findings are in line with other commonalities that researchers have discovered in the last few years.

Around 120 years ago, US doctor Eugene Lindsay Opie discovered unusual protein deposits in the pancreases of patients with type 2 diabetes that were similar to those found in the brain for many neurodegenerative diseases. Type 2 diabetes is one of the most widespread diseases, formerly known as adult-onset diabetes. The deposits, known as islet amyloid, comprise tiny protein threads known as fibrils. In the case of diabetes, they consist of the peptide hormone IAPP. In the pancreas, they contribute to the death and dysfunction of beta cells that are responsible for producing insulin. The hormone plays an important role in reducing blood sugar levels.

"These amyloid fibrils have been intensively researched for many years. For a long time, however, it was only possible to draw on very low-resolution structures," explains Gunnar Schröder from Forschungszentrum Jülich and Heinrich Heine University Düsseldorf. In 2017, together with partners and colleagues, Schröder presented one of the first-ever atomic-level 3D models of such a fibril: in this instance an Alzheimer's fibril comprising an amyloid beta peptide (Abeta).

"For the first time, we have succeeded in achieving a 3D reconstruction of an IAPP fibril typical for diabetes in comparable resolution," Schröder says. The resolution achieved by the team of 4 angstroms, corresponding to 0.4 nanometres, is within the magnitude of atomic radii and atomic bond lengths. In addition to other details, the precise arrangement of the molecules in the fibrils is thus made visible for the first time. The model shows how individual IAPP molecules are stacked on top of each other to form fibres with an S-shaped cross section. The structure is similar to that of the S-shaped fold in Abeta fibrils that are typical for Alzheimer's.

"This similarity is interesting. There is an epidemiological correlation between Alzheimer's and diabetes: Alzheimer's patients have a greater risk of contracting diabetes and vice versa," explains Wolfgang Hoyer, who also conducts research at Heinrich Heine University Düsseldorf and Forschungszentrum Jülich. There are also other correlations. For example, scientists have already detected small impurities of "foreign" IAPP peptides that are typical of diabetes in the amyloid deposits of Alzheimer's patients. Furthermore, when one of the type of fibrils is added, there is increased growth of deposits of the other type, as researchers discovered in tests on mice.

The new high-resolution fibril model now provides a platform for gaining a better understanding of the formation of the fibrils in the case of diabetes and for developing drugs that can directly tackle the cause of the disease. "Inhibitors can now be developed, for instance, in a targeted manner to suppress the formation of the fibrils," explains Hoyer, who has been researching binding proteins in this field for a number of years now. Such proteins prevent individual molecules from forming amyloids and can thus delay, or even halt, the outbreak of diabetes, Alzheimer's, and Parkinson's. Another approach is the development of substitutes for the IAPP peptide that are not prone to the formation of fibrils. Among the functions that IAPP assumes is that of an appetite-suppressing hormone in the body. The substitutes are not only interesting therefore for the treatment of type 2 diabetes but also the treatment of other diseases such as type 1 diabetes and morbid obesity.

Background: cryo-electron microscopy

Cryo-electron microscopy is still a relatively new research method for determining the structure of biomolecules on the atomic level. Jacques Dubochet, Joachim Frank, and Richard Henderson were awarded the 2017 Nobel Prize in Chemistry for developing this method.

Cryo-electron microscopy fulfils similar tasks to the long-established methods of X-ray crystallography and NMR spectroscopy. With X-ray crystallography, biomolecules such as proteins, DNA, or bacteria and viruses first have to be converted into crystalline form. By contrast, with cryo-electron microscopy and NMR spectroscopy, the protein building blocks can be investigated in their natural state. In the case of cryo-electron microscopy, the specimens are first dissolved in water, then flash frozen, and finally investigated with an electron microscope. This method has particular advantages when it comes to investigating large structures composed of hundreds or thousands of proteins.

People born small for gestational age (SGA) have a lower IQ throughout development, however the differences in IQ to those born appropriate for gestational age (AGA) reduce by adulthood. The effects of SGA on IQ are nearly as large as being born into lower socio-economic status or receiving poor parenting in infancy.

It has been previously determined by researchers from the University of Warwick that those with a smaller head circumference at birth and subsequent poor head growth have a lower IQ. This research has now led them to look at whether cognitive performance from infancy to adulthood is affected by being born small for gestational age.

The researchers also determined whether other aspects such as being very preterm/very low birth weight, socioeconomic status and parent-infant relationship influence SGA's effect on cognitive performance.

In the paper, 'Small for Gestational Age - Cognitive Performance from Infancy to Adulthood: An Observational Study', published in the journal British Journal of Obstetrics and Gynaecology researchers from the Department of Psychology at the University of Warwick have found that those born small at gestational age have a lower IQ throughout development.

The researchers followed 203 VP/VLBW (under 32 weeks gestational age and/or under 1500g) and 198 term born children (between 37 and 41 weeks gestation) in Germany born in 1985-6 into adulthood.

They determined SGA using 2 different methods, growth charts based on birth weight and growth charts normed on ultrasound measurement in pregnancy (foetal reference). They also assessed the parent's socioeconomic status and parent-infant relationship before the infant was 5 months old, and had participants do a developmental and IQ tests on six occasions, from 5 months to 26 years old.

While the foetal reference classified more infants as SGA than the neonatal reference, SGA using either reference was associated with an IQ -8 points lower than those born appropriate for gestational age (AGA), with the difference narrowing into adulthood.

Independent of being SGA, being born very preterm or very low birth weight was associated with IQ -16 points lower than term-born participants. Furthermore coming from a low socioeconomic family was associated with -14 point lower IQ than those from a high socioeconomic status.

It was also found that a poor parent-infant relationship was associated with IQ-10 lower than those with a good Professor Dieter Wolke, from the Department of Psychology at the University of Warwickrelationship between infant and parent.

Professor Dieter Wolke, from the Department of Psychology at the University of Warwick comments:

"SGA, whether born preterm or at term, seems to have adverse effects on cognitive development that are long lasting. Reassuring is that there is some catch-up in IQ into adulthood."

"In contrast, being very preterm, into a lower socio-economic status or having experienced poor parent-infant relationship has further and even more severe adverse effects on IQ."

Robert Eves, the first author from the Department of Psychology at the University of Warwick adds: "This shows us that those born SGA need extra interventions to ensure their cognitive development is not put at jeopardy, especially if social risk factors are also experienced by the infant.

"Such interventions could include optimised nutrition to ensure optimal catch up growth following SGA birth or interventions for improving the parent-infant relationships"

There is a clear link between improved gut microbiota and one of our most common cholesterol-lowering drug groups: statins. This is evident from a European study involving researchers from the University of Gothenburg.

Scientists have previously found an association between the gut microbiota and various metabolism-related and cardiovascular diseases. Now the current study, published in the journal Nature, shows improvement in gut microbiota in the participant group who were taking statins.

The direct mechanisms have not been identified. Nonetheless, in this first major publication from MetaCardis (Metagenomics in Cardiometabolic Diseases), a collaborative EU-based project involving 14 research groups from six countries, the results are unequivocal.

One of the authors is Fredrik Bäckhed, Professor of Molecular Medicine at Sahlgrenska Academy, University of Gothenburg, who focuses on the role of gut microbiota in metabolism.

"Although the study does not provide a causal link," he says, "it's exciting to see how a well-established and clinically used drug can change the gut microbiota. Time will tell whether statins affect bacteria in the gut directly or whether these drugs affect both gut and immune cells that, in turn, help modify the microbiota."

The purpose of MetaCardis is to clarify whether and how gut microbiota may be linked to cardiovascular disease. In the project, more than 2,000 Europeans with varying degrees of metabolic and cardiovascular disease have been meticulously investigated.

The gut microbiota is divided into various main groups, known as enterotypes, that vary among individuals. One of these, labeled Bact2, has fewer bacteria in terms of number and composition alike. Microbes lacking in Bact2 include anti-inflammatory bacteria like Faecalibacterium, one effect of which is to strengthen the immune system.

Bact2 is more common in patients with inflammatory bowel disease (IBD), multiple sclerosis and depression. In the current study, the scientists found this enterotype also to be significantly more prevalent in patients with obesity (18%) than people without it (4%) -- an observation verified in an independent Belgian study.

The positive and hitherto unknown effect of statins identified by the researchers was that the proportion of individuals with Bact2 decreased in the group given statin therapy, resulting in a more normal gut microbiota. Together, the various study findings open up for new forms of treatment in the future, in which drugs can be used to alter the gut microbiota.

"Perhaps drugs like statins can be used to change the ecology in the gut. But that calls for further studies," Bäckhed notes.

Researchers at the Francis Crick Institute have found two genes that regulate the differentiation of stem cells in the small intestine, offering valuable insight into how the body develops and maintains a healthy gut.

Cells in the lining of the small intestine are replaced around every five days, the quickest rate for any organ in the body. This fast replacement helps the lining cope with the damage it suffers as a result of breaking down food and absorbing nutrients.

This process, which is important for the healthy functioning of the small intestine, is supported by the stem cells in a part of the small intestine called the crypt.

In their study, published in Gastroenterology, the researchers found two genes, MTG8 and MTG16, which are highly expressed in cells that have just left the stem cell zone. These genes 'switch off' signals that keep these cells in a multipotent or 'immature' state, leading them to start to differentiate.

When the team analysed intestinal tissue and small intestine organoids grown from mice lacking these genes, they found there were many more stem cells, indicating that the process of differentiation was impeded.

Anna Baulies, lead author and postdoctoral training fellow in the Stem Cell and Cancer Biology lab at the Crick says: "These genes maintain the flow of cells which are needed for the healthy functioning of the small intestine, starting the stem cells on the road to become enterocyte cells which are needed to absorb nutrients."

Importantly, by working with human small intestine organoids, the researchers also found that while the stem cells are still in the crypt, these genes are repressed by a key developmental pathway, Notch signalling. This ensures the stem cells do not differentiate too early.

Vivian Li, senior author and group leader of the Stem Cell and Cancer Biology lab at the Crick says, "Understanding the role these genes play in healthy tissue will also help us to understand how the intestine regularly regenerates and also if these genes are a helpful or harmful force in the presence of disease."

"For example, loss of these genes may increase the number of stem cells and contribute to colorectal cancer progression. Further study on the underlying mechanism might be helpful to limit the number of stem cells in the cancer."

The signal that these genes repress, Wnt signalling, also keeps stem cells in a multipotent state in many other tissues, including the skin, stomach, liver and brain. These findings could therefore help other research into stem cell differentiation outside of the small intestine.

The researchers will continue this work, looking to understand more about the mechanism these two genes use to regulate stem cell differentiation and regeneration.

The discovery of a tiny insect fossil is unearthing big questions about the global movement of animals and the connection to changes in climate and shifting continents across deep time. The fossil, estimated to be 50 million years old, was found in rocks near the city of Kamloops, British Columbia, but today its relatives live exclusively in Australia.

The finding is the latest in a pattern of discoveries that are leading experts to contemplate a Canada-Australia connection not previously considered. Paleontologists Bruce Archibald of Simon Fraser University and the Royal British Columbia Museum and Vladimir Makarkin of the Russian Academy of Sciences in Vladivostok published their findings in The Canadian Entomologist.

According to Makarkin, the fossil is part of the "split-footed lacewing" family. Little is known about this group over the 66-million-years following the extinction of the dinosaurs. "These fossils are rare," he says. "This is only the fourth one found from this time-span world-wide, and it's the most completely preserved. It adds important information to our knowledge of how they became modern."

The paleontologists identified the fossil by the characteristic network of veins covering its wings. They emphasize that fossils like the new lacewing species help in understanding large-scale patterns of the modern distribution of life across the globe.

Previous fossil insects of this age found in B.C. and neighbouring Washington have shown connections with Pacific-coastal Russia to the west and with Europe to the east - patterns that are not surprising since the northern continents were connected then.

"Fifty million years ago, sea levels were lower, exposing more land between North America and Asia, and the Atlantic Ocean had not widened, leaving Europe and North America still joined across high latitudes," says Archibald. He explains that the far-north experienced warmer climates then as well, helping a variety of animals and plants to disperse freely between northern continents.

The Australian connection is more puzzling though, as there is no such clear land connection. That continent was closer to Antarctica then and farther from Asia than today, leaving formidable ocean barriers for life to disperse between it and Canada's west coast.

This lacewing joins other insect fossils from B.C. and Washington whose modern relatives only live in the Australian region. These include bulldog ants, a family of termites, and a kind of parasitoid wasp.

Archibald says that "a pattern is emerging that we don't quite understand yet, but has interesting implications."

The researchers suggest that the answer might be connected to climate. The forests of the ancient British Columbian temperate upland where this lacewing lived had very mild winters, in fact, probably without frost days.

The climate of modern Australia shares these mild winters even in temperate regions. "It could be that these insect groups are today restricted to regions of the world where climates in key ways resemble those 50 million years ago in the far western Canadian mountains," says Archibald.

Archibald and Makarkin emphasise that it's important to understand the little things in order to appreciate the big picture. "The more we know about these insects, the more we can piece together the history of how climate and the movement of continents have shaped global patterns of the distributions of life that we see in our modern world," says Makarkin.

"To understand where we are today and where we may be going with the big changes that we are seeing in global climates, we need to understand what's happened in the deep past."

Widespread hot extremes are seen across the world in recent years, causing heat-related mortality and harmed crops and livestock. In summer 2018, a record-breaking heat wave swept large areas of Northeast Asia. The China Meteorological Administration issued high-temperature warnings for 33 consecutive days. In Japan, at least 71,266 required hospitalization for heat stroke.

To make it worse, 2018 heat wave was probably not a random or an individual case according to a new study published in Environmental Research Letters.

In the study, 2018 heat wave was used as a rear-view mirror to investigate what has caused more extreme summer heat event over Northeast Asia, and in particular, to look into the role of anomalous anticyclone over Northeast Asia.

An anticyclone is an area of high atmospheric pressure, which causes settled weather conditions, and, in summer, clear skies and high temperatures. But how much the anomalous anticyclone circulation would contribute to extreme heat events over Northeast Asia still remains unknown.

"Our study, for the first time, gave a quantitative estimation of the contribution of circulation to such a heat event over Northeast Asia, by using the flow analogue method," said Liwen Ren, the lead author, a Ph.D student from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences and University of Chinese Academy of Sciences. "We found that anomalous anticyclone over Northeast Asia was responsible for nearly half of the magnitude in extreme heat events of 2018."

The researchers found that such anomalous anticyclones similar to that in 2018 became worse and more common in recent decades (1991-2017) than the past (1958-1990).

Further, this kind of dynamical (anticyclone) change in recent decades, together with thermodynamical change (e.g. mean temperature shift towards to warmer state with increasing greenhouse gases) have made such kind of extreme heat events more likely happen over Northeast Asia.

"We also found that, the more extreme the heat event is, the larger contribution of thermodynamical change will be, with a contribution of at least 80%," said Prof. Tianjun Zhou, the corresponding author. "This implies that as long as global warming continues, we would face higher risk for extreme heat events over Northeast Asia in the next decades."

Hartford, CT - 91% of LGBTQ adolescents in a US survey report at least one experience of bias-based bullying, according to a new study published in the American Journal of Preventive Medicine by researchers at the Rudd Center for Food Policy and Obesity at the University of Connecticut. This number is more than double estimates from previous studies with predominantly heterosexual youth.

By the time they reach middle school, sexual and gender minority (SGM) adolescents are at heightened risk of suicide, depression, sleep troubles, and eating disorders. These health consequences often stem from the distress of being stigmatized for their sexual and gender identities. Based on this knowledge, researchers wanted to learn whether being mistreated for other reasons (such as their weight, race/ethnicity, religion, disability status) also contributes to their health.

"When considering approaches to reduce health risk, we need to better understand the wide range of bias-based bullying experienced by SGM adolescents," says Leah Lessard, postdoctoral fellow at the Rudd Center and lead author of the study. "Given that multiple forms of bias-based bullying can worsen negative health behaviors, it is critical to understand how school-based interventions, such as Gay Straight Alliances (GSAs), may be able to reduce targeted bullying."

The study reports findings from the LGBTQ National Teen Survey, a comprehensive survey conducted in partnership with the Human Rights Campaign to assess victimization, health behaviors, family relationships, and experiences of LGBTQ adolescents across the United States. Researchers asked participants ages 13-17 questions about school-based GSAs, their experiences of bias-based bullying, and health risk indicators, including stress, sleep problems, depression, and unhealthy weight behaviors.

Key findings include:

* 73% of SGM adolescents surveyed reported experiences of bias-based bullying for reasons beyond their sexual or gender identities, such as being bullied because of their body weight (57%), race/ethnicity (30%) and religion (27%).

* Each type of bullying was positively related to health risk, including depression, sleep problems, stress, and unhealthy weight control behaviors.

* The presence of a Gay Straight Alliance at school was associated with less bullying of students for their weight, gender, religion, disability, and sexuality.

Given these results, GSAs have positive implications for not only students facing LGBTQ-related bullying, but also for those who experience other types of bias-based bullying. By reducing rates of targeted victimization, these organizations may help lower the risk of unhealthy behaviors in vulnerable adolescents.

"The harmful effects and wide range of bias-based bullying experienced by SGM youth calls attention to the importance of promoting broad-reaching inclusion and acceptance within schools, " said Lessard. "Due to the breadth of stigma-reduction across multiple social identities, our results underscore GSAs as a promising avenue to support healthy outcomes for SGM youth."

These findings are particularly important as schools face new challenges in the midst of the COVID-19 pandemic. As smartphones and social media usage increase, the possibility for bias-based cyberbullying does too. Educators and student leaders can host virtual GSA meetings and utilize online learning platforms to continue to foster social inclusion for adolescents at risk for victimization in the absence of in-person meetings.

BOSTON - In its first randomized clinical trial, a drug that targets a protein needed by cancer cells to maintain their dogged growth and division has shown considerable promise in combination with chemotherapy in patients with a common form of ovarian cancer, investigators at Dana-Farber Cancer Institute report.

As detailed in a paper published online today by The Lancet Oncology, patients with high-grade serous ovarian cancer (HGSOC) who were treated with the drug, berzosertib, and chemotherapy lived substantially longer before their disease began to worsen than did those treated with chemotherapy alone. The findings may set the stage for testing berzosertib - an inhibitor of the ATR protein - in a range of other cancers, investigators say.

"Our results in his phase 2 trial suggest that ATR inhibition in combination with chemotherapy has the potential to offer significant benefit to patients with chemotherapy-resistant HGSOC and, potentially, other tumor types where ATR plays a key role," says the study's lead author, Panagiotis Konstantinopoulos, MD, PhD, director of translational research, Gynecologic Oncology, at Dana-Farber.

Berzosertib is designed to take advantage of one of the most glaring vulnerabilities of some cancer cells. Like a tractor run non-stop, a tumor cell, driven by a constant imperative to proliferate, is apt to need frequent repairs. In a tumor cell, that involves fixing broken strands of DNA.

HGSOC, like other types of cancer, relies heavily on the ATR protein in making those repairs. That reliance becomes even greater when these cancers are treated with chemotherapy, which disrupts cells' ability to copy their DNA.

"The unbridled growth of cancer cells places enormous stress on the process of DNA replication," Konstantinopoulos explains. "ATR helps them survive that stress: its job is to coordinate the halting of the cell cycle to check if the DNA is intact or needs repair. Drugs that inhibit ATR - that deprive tumor cells of such repair - have the potential to be particularly effective in some cancers."

In the study, investigators at 11 cancer centers around the country enrolled 70 patients with HGSOC that was resistant to platinum-based chemotherapy. Half the participants were randomly assigned to receive the standard chemotherapy agent gemcitabine alone and half received gemcitabine in combination with berzosertib.

The estimated median progression-free survival of patients receiving gemcitabine alone - the period in which their disease was in retreat or stable - was 14.7 weeks. For those receiving gemcitabine and berzosertib, it was 22.9 weeks. Among patients with the most platinum resistant tumors (i.e. those who had progressed within 3 months from prior platinum-based chemotherapy), the difference was even greater: 9 weeks for gemcitabine versus 27.7 weeks for gemcitabine and berzosertib.

Side effects were similar in the two groups. Those receiving the combination therapy, however, had a higher rate of thrombocytopenia, or low blood platelet levels.

Water and its interactions with other substances are essential to human life. However, understanding the structure of liquid water and its hydrogen-bonding networks has been a challenge.

According to previous studies, all oxygen atoms in water trimers, tetramers, and pentamers with cyclic minimum-energy structures exist in a two-dimensional (2D) plane. In contrast, water hexamers have noncyclic three-dimensional (3D) structures. Therefore, the water hexamer was long considered to be the smallest water droplet with a 3D hydrogen-bonding network.

This understanding has now changed due to work by Chinese scientists.

A research team led by Prof. JIANG Ling and Prof. YANG Xueming from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Prof. LI Jun from Tsinghua University, has now revealed that the noncyclic 3D structure of water clusters begins to exist with pentamers at low finite temperatures.

The study was published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) on June 15.

Profs. JIANG and YANG developed a method of infrared spectroscopy of neutral clusters based on a tunable vacuum ultraviolet free electron laser (VUV-FEL). This method creates a new paradigm for the study of vibrational spectra of a wide variety of neutral clusters that could not be studied before.

They measured IR spectra of size-selected neutral water clusters using the VUV-FEL-based IR scheme. Distinct new OH stretch vibrational fundamentals observed in the 3500-3600 cm-1 region of (H2O)5 provide unique spectral signatures indicating the formation of a noncyclic pentamer.

Prof. LI's team carried out quantum chemical studies to understand the structural and spectral changes in these clusters. A three-center two-electron (3c2e) model was proposed to describe the bonding nature of the hydrogen-bonding network of water clusters.

The results revealed that the striking spectral change in the OH stretch region could be attributed to the appearance of 3D hydrogen-bonding networks in pentamers at finite temperature, suggesting that water clusters exhibit a noncyclic 3D structure beginning with pentamers, not hexamers, as previously thought.

The scientists' findings provide a consistent picture of the structural diversity of the hydrogen-bonding networks that are responsible for the major structural features and properties of water in the condensed phase.

Following two studies that screened thousands of human antibodies to SARS-CoV-2 to identify highly potent pairs, in which both antibodies bind the viral target simultaneously, a resultant antibody cocktail is being tested in human trials. The double-antibody approach, versus use of a single antibody, is designed not only to be effective as a treatment, the authors say, but to protect against antibody resistance that might arise in response to selective pressure from single antibody therapies, which are also being explored to treat COVID-19. With the urgency of developing a therapeutic against COVID-19, researchers have focused on antibodies that target the viral spike and prevent SARS-CoV-2 from entering host cells. Here, using genetically humanized mice as well as B cells derived from recovering COVID-19 patients, Johanna Hansen et al. isolated thousands of fully human antibodies to SARS-CoV-2 with varied binding properties and antiviral activity. From this collection, they sought pairs of highly potent individual antibodies that could simultaneously bind the critical Receptor Binding Domain (RBD) of the virus spike protein; the goal of using a pair of antibodies, versus a single antibody treatment, is to increase the chances the therapy could counter any so-called “virus escape mutants” that might arise in response to selective pressure from a single antibody. Hansen et al. identified several neutralizing antibodies, including pairs that did not compete for binding to the RBD.

In a second study seeking to address concerns about antibody resistance, Alina Baum et al. focused on four of these antibodies. The authors tested them against a breadth of spike RBD variants known to exist in humans. To further explore the potential for resistance to these antibodies, the authors generated a pseudo SARS-Cov-2 virus (VSV-SARS-CoV-2-S) that expresses the spike protein. By growing the pseudovirus with sub-neutralizing concentrations of their top antibodies, they allowed escape mutations to emerge – a proxy for mutations that could arise as the pandemic continues. For some combinations of their four antibodies, virus escape still occurred. This only stopped when they used combinations of antibodies that did not compete or only partially competed for binding on the RBD, they say. The authors of both studies say their data strongly supports use of double (“cocktail”) antibody therapy in which two antibodies were chosen so as to bind to distinct and non-overlapping regions of the viral target. Hansen et al. write: “Inclusion of such antibodies into an antibody cocktail may deliver optimal antiviral potency while minimizing odds of virus escape.” Such an antibody cocktail is now being tested in human trials (clinicaltrials.gov NCT04426695 and NCT04425629).

The communities of tiny picoplankton in oceans reveal a great deal about the health of marine ecosystems and food webs. KAUST researchers have examined how numbers of these organisms vary across the year in both coastal and offshore locations in the Red Sea, while investigating the predators and viruses that control them.

The bacterial elements of plankton largely drive energy flows in the aquatic food web in nutrient-poor regions by photosynthesizing and recycling dissolved carbon and other nutrients. Cyanobacteria are autotrophic, meaning they generate their own food using resources, such as light and carbon dioxide. In turn, heterotrophic bacteria and archaea feed on the dissolved organic matter present in the water. Both groups provide food for other organisms, including grazers like heterotrophic nanoflagellates.

"These two latest studies fill a gap in our understanding of tropical marine ecosystems--how bacterioplankton communities are structured and how they function in these vast, underexplored regions," says Xosé Anxelu G. Morán at KAUST's Red Sea Research Center, who supervised students Eman Sabbagh1 and Najwa Al-Otaibi2, and their co-authors.

"Oceanographic research has largely been conducted by countries located in temperate and subpolar regions in the Northern Hemisphere," Morán continues. "It has long been assumed that tropical seas would not have the same seasonal variation in bacterial community dynamics as temperate regions. KAUST's location and resources enable us to investigate bacterioplankton in tropical seas in greater detail than ever before."

Sabbagh's paper focused on shallow coastal waters, analyzing samples from KAUST Harbor every week for a year. They wanted to understand these autotrophic communities and the impact of top-down factors--viral attack and heterotrophic nanoflagellate grazing--as well as the effects of bottom-up factors, such as nutrient availability.

"Our fine-resolution sampling meant we documented direct and sustained predator-prey dynamics between viruses and their bacterial hosts," says Sabbagh. "Mortality due to viruses, along with nanoflagellate grazing, seemed to dominate Red Sea coastal bacterioplankton losses throughout much of the year. This suggests that top-down control is fundamental in regulating bacterial abundance."

Al-Otaibi's paper focused on an offshore site in the central Red Sea, where they collected water samples from fixed depths down to 700 meters periodically over two years. They measured the abundance and cellular characteristics of different autotrophic and heterotrophic picoplankton groups, while monitoring environmental variables.

"Our results showed a clear seasonal variation, particularly in surface groups (the upper 100 meters), with a peak in numbers of autotrophic picoplankton in summer and a lull in winter," says Al-Otaibi. "Importantly, our study is the first detailed account of the effect of vertical gradients on the distribution of picoplankton communities over the seasons. This seasonality should be included in all future studies of the Red Sea pelagic ecosystem."

"Long-term, well-maintained studies of tropical sites will be fundamental to prove current hypotheses about the future directions of change in the hottest water bodies on Earth," says Morán. "In addition, we may gain insight into our future oceans because if we do not slow down climate change, then current conditions in tropical regions will be met shortly in higher latitudes."