Earth

The phenomenon of using DNA from old fossils preserved in amber already inspired Hollywood - in the film Jurassic Park, scientists reproduce the DNA of dinosaurs extracted from a fossil mosquito embedded in a piece of amber and thereby resurrect them. In reality, however, the undertaking is much more difficult: all previous studies in which researchers took DNA samples from insects enclosed in tree resin were the results of modern environmental contamination and, in addition, were unreproducible, subsequently useless under the scientific method. An international team led by researchers at the University of Bonn now detected DNA from ambrosia beetles that were trapped in recent tree resin for less than seven years. The study was published in the journal PLOS ONE.

Using so-called ancient DNA, scientists can draw conclusions about long gone times and the organisms living there. The use of organisms trapped in amber (fossil tree resin) with this finality was thought not to be possible after relatively recent fails in looking for DNA in a few thousand-year-old samples.

"Our new results show that it is indeed possible to genetically study organisms that were embedded in resin, although we do not know the time limit yet" emphasizes study leader Dr. David Peris of the Institute for Geosciences and Meteorology at the University of Bonn. The superordinate aim of the researchers is to dissolve step by step fundamental aspects of the DNA preservation in the resin and to determine the real temporal border, until when DNA in resins remains preserved.

Focus on relatively young resin samples

"Instead of looking for DNA in amber of 100 million years old or more, to dream about the resurrection of dinosaurs, we should start by detecting it in insects trapped a few years ago in resin," highlights David Peris. The resin samples used were six and two years old and came from Madagascar. To detect the DNA, the scientists established a method based on the technique called polymerase chain reaction, which makes it possible to multiply genetic material in a test tube. This method is well-known in criminology and recently became famous, as the basic technology for the detection of the SARS-CoV-2. "This method allowed us to perform several authenticity checks, so that we could say certain that the detected DNA in our experiments was indeed from the beetles preserved in the resin," explains Kathrin Janssen of the Institute of Medical Microbiology, Immunology and Parasitology, also part of University of Bonn, the second lead author.

The researchers found that water is stored in the embedded samples longer than previously thought, which has a negative effect on the stability of the DNA. In the future, the scientists plan to gradually analyze older samples with more sensitive "next generation sequencing" methods. "Investigating the time limit of DNA conservation and many other related issues is the aim of future experiments," summarizes Kathrin Janssen.

Life on Earth is all about strategies for survival, with every organism developing behaviors and bodies that maximize chances of staying alive and reproducing while minimizing the likelihood of being injured or eaten.

Fish are one such example. For millions of years, many species have evolved a safety-in-numbers strategy that confuses predators and ensures the survival of the maximum number of individuals as they move about in the ocean. According to scientists at UC Santa Barbara, the Santa Fe Institute and the University of Washington, however, thanks to modern industrial fishing practices and technologies, schooling behavior may become less common.

"The findings from our model suggest that industrial fishing can decrease the tendency of fish to form large groups," said UCSB graduate student researcher Ana Sofia Guerra, lead author of a paper published in the journal Proceedings of the Royal Society B. This change in behavior has implications for both the fish and their predators, including humans.

"People have been studying fisheries science for centuries," added marine ecologist and paper co-author Douglas McCauley, an associate professor of ecology, evolution and marine biology at UC Santa Barbara. "But we've never considered: Could modern fishing technology be killing schooling behavior?"

Indeed, the capacity to extract large amounts of fish from the ocean has grown in the past several decades, with ships and fleets able to access and fish from even remote areas of the ocean. Purse-seining and trawling both involve deploying enormous nets that target large groups of fish. Drones and spotter planes increase the efficiency of these mass-capture methods.

"One of the reasons schooling behavior exists is to avoid a predator attack, but by developing technology that can capture entire schools, we have turned the tables on that strategy," Guerra said.

To better understand this effect, Guerra and McCauley, along with colleagues Albert Kao from the Santa Fe Institute and Andrew M. Berdahl from the University of Washington, constructed an evolutionary fission-fusion model to simulate the behavior of individual schooling fish faced with different levels of predation, both natural and human. The model describes changes in fishes' preference to form large schools while subjected to different levels of human fishing pressure and natural predation.

The results show that the larger the prevalence of mass-capture practices relative to natural predation, the more individual fish preferences shift toward smaller group sizes.

"Suddenly the sardine in a big school is a lot more vulnerable to a human predator than one that prefers smaller schools or a solitary lifestyle," Guerra said. Collectively, this change in preference will result in smaller groups and more solitary individuals.

In fact, this change could have several impacts, according to the researchers. For one thing, natural predators that rely on these fish also have evolved hunting methods based on the fishes' tendencies to travel in large groups.

"We are not the only predators who have figured out how to exploit schooling fish," Guerra said. Seabirds and pelagic predators often coordinate their attacks. Humpback whales corral herring using 'bubble nets' before swooping in, although their ability to exploit schools is not as effective or expansive as that of humans. "By altering schooling behavior, we could actually impact marine predators that rely on schooling fish," she said.

It's a socioeconomic issue, too. Foragefish, which include anchovies, herring and sardines, are a large segment of the global fishing industry, valued at $16.9 billion. The economy and efficiency of their capture makes them the basis of thousands of livelihoods. Changes in their schooling behavior might require more time, effort and resources to catch them, which puts the fisheries in a vulnerable position.

Is it reversible? Yes, but only after a lag that would allow the fish to evolve their preferences similar to those observed in the absence of fishing, according to the paper.

"If you wanted to reverse the effects of fishing on a fish population's tendency to school, you would have to reduce fishing to a much lower level than what it took to cause the effect in the first place," Guerra said.

Especially worrying is their finding that it is difficult to see these impacts on schooling until it is too late -- data is incomplete at best. For example, data from purse-seining operations will focus on large schools and ignore the smaller schools. "If what happens in these models is actually playing out in the ocean, it means we may keep catching fish schools, thinking everything is fine," McCauley said. "Until we catch the last school. And discover that everything is not fine."

This wouldn't be the first time large-scale fishing has introduced evolutionary pressures into fish populations. For instance, the practice of selecting for the largest individuals, has, generation over generation, produced smaller adults in some species.

"Because we consistently harvest the largest fish in the population, it has become an advantage for them to be smaller -- they are less of a target and therefore more likely to survive and reproduce," Guerra explained. "With intense fishing pressure, it is also advantageous to reproduce earlier at a smaller size." This phenomenon has already occurred with salmon in the Atlantic and Pacific Oceans, in Europe and North America.

This research is an investigation into the area of the behavioral consequences of targeting large schools, a rather underexplored area of fishery science. Most research assumes that fish behaviors do not change.

"Fishery science sometimes tends to treat fish as just numbers on an accounting sheet," McCauley said. "Our work reminds us that fish are not just numbers. They are living animals with behavior.

"We know from many contexts that hunted animals can shift behavior slowly to evade capture -- this seems to be possible for fish as well," he continued. "Our models suggest fishing could very easily be changing fish behavior in ways that affect both fish and fishers."

A study of more than a half-million people in India who were exposed to the novel coronavirus SARS-CoV-2, or COVID-19, suggests that the virus' continued spread is driven by only a small percentage of those who become infected.

Furthermore, children and young adults were found to be potentially much more important to transmitting the virus -- especially within households -- than previous studies have identified, according to a paper by researchers from the United States and India published Sept. 30 in the journal Science.

Researchers from the Princeton Environmental Institute (PEI), Johns Hopkins University and the University of California-Berkeley worked with public health officials in the southeast Indian states of Tamil Nadu and Andhra Pradesh to track the infection pathways and mortality rate of 575,071 individuals who were exposed to 84,965 confirmed cases of SARS-CoV-2. It is the largest contact-tracing study -- which is the process of identifying people who came into contact with an infected person -- conducted in the world for any disease.

Lead researcher Ramanan Laxminarayan, a senior research scholar in PEI, said that the paper is the first large study to capture the extraordinary extent to which COVID-19 hinges on "superspreading," in which a small percentage of the infected population passes the virus on to more people. The researchers found that 71% of infected individuals did not infect any of their contacts, while a mere 8% of infected individuals accounted for 60% of new infections.

"Our study presents the largest empirical demonstration of superspreading that we are aware of in any infectious disease," Laxminarayan said. "Superspreading events are the rule rather than the exception when one is looking at the spread of COVID-19, both in India and likely in all affected places."

The findings provide extensive insight into the spread and deadliness of COVID-19 in countries such as India -- which has experienced more than 96,000 deaths from COVID-19 -- that have a high incidence of resource-limited populations, the researchers reported. They found that coronavirus-related deaths in India occurred, on average, six days after hospitalization compared to an average of 13 days in the United States. Also, deaths from coronavirus in India have been concentrated among people aged 50-64, which is slightly younger than the 60-plus at-risk population in the United States.

The researchers also reported, however, the first large-scale evidence that the implementation of a country-wide shutdown in India led to substantial reductions in coronavirus transmission.

The researchers found that the chances of a person with coronavirus, regardless of their age, passing it on to a close contact ranged from 2.6% in the community to 9% in the household. The researchers found that children and young adults -- who made up one-third of COVID cases -- were especially key to transmitting the virus in resource-limited populations.

"Kids are very efficient transmitters in this setting, which is something that hasn't been firmly established in previous studies," Laxminarayan said. "We found that reported cases and deaths have been more concentrated in younger cohorts than we expected based on observations in higher-income countries."

Children and young adults were much more likely to contract coronavirus from patients their own age, the study found. In general, same-age contacts across all age groups greatly increased the chance of infection, with the probability of catching coronavirus from low- to high-risk contacts ranging from 4.7-10.7%, respectively.

In two states in India, Tamil Nadu and Andhra Pradesh, COVID-19 cases and deaths have been more heavily concentrated in younger cohorts than is seen in high-income countries, among other trends. These results, from a study based on surveillance and contact tracing data, offer a window into the pandemic's trajectory in a low- and middle-income country, where most COVID-19 cases have occurred, and from which insights to guide control measures are urgently needed. While multiple modeling studies have attempted to assess how COVID-19 might affect people and communities in low-and middle-income countries, almost no primary studies of disease dynamics and clinical outcomes of COVID-19 are available from these locations, to validate models and inform intervention strategies. The populations of Andhra Pradesh and Tamil Nadu - states with among the largest healthcare workforces in India - account for approximately 10% of the country's total population. Both states began rigorous disease surveillance and contact tracing early in response to the pandemic. Ramanan Laxminarayan and colleagues analyzed surveillance and contract tracing data from these two states' programs. Epidemiological data and laboratory test results were available from 575,071 tested contacts of 84,965 confirmed cases. Analyzing these and other data, the authors report that cases and deaths in the two Indian states were concentrated in younger cohorts than expected from observations in higher-income countries, findings that "may indicate the identification of less-severe infections through active case-finding," the authors say. Same-age contacts were associated with the greatest infection risk, a pattern strongest among children ages 0-14 years and among adults older than 65 years. Case-fatality ratios spanned 0.05% at ages 5-17 years to 16.6% at ages exceeding 85. The authors note that estimates of time-to-death in both states is rapid compared to what has been observed internationally (for example 13 days to death from the date of hospital admission in the U.S., compared to succumbing to death within six days in the two Indian states, for about half of the cases ascertained in this study). The most prevalent conditions among those who died were diabetes, sustained hypertension, coronary artery disease, and renal disease, with at least one comorbid condition noted among 62.5% of fatalities, in comparison to 22% of fatalities in the United States as of 30 May, 2020. In the two Indian states, only 17.9% of COVID-19 deaths occurring on or before 1 August, 2020 were among people older than 75, compared with 58.1% of COVID-19 deaths in the United States. "While the role of children in transmission has been debated," the authors write, "we identify high prevalence of infection among children who were contacts of cases around their own age." The authors note several implications and limitations of their study. They conclude: "Similar studies are necessary to inform the successful adaption of epidemic control measures in low-resource settings globally."

A new study led by researchers from the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) warns that the negative effects of rapid ocean warming on planktonic communities will be exacerbated by ocean acidification.

The research, recently published in the journal Scientific Reports of Nature, shows that some of the major environmental changes projected for this century in the Mediterranean Sea (e.g., ocean acidification, ocean warming, and the increasingly frequent marine heatwaves in summer) can have adverse effects on the productivity of calcifying phytoplankton communities (coccolithophores).

Carbon dioxide (CO2) emissions by human activities have alarmingly increased in the past decades. A quarter of this anthropogenic CO2 has been absorbed by the ocean, changing the chemistry and ultimately lowering the pH of the seawater, a phenomenon known as ocean acidification.

The extra heat trapped in the atmosphere due to greenhouse gases is also causing the warming of the seawater (which annually absorbs up to 90% of this heat). The process hampers the supply of nutrients to the upper ocean layers, due to a sharp stratification of the surface water column.

"Atmospheric warming is expected to evolve in the Mediterranean area 20% faster than the global average, and marine heatwaves will occur with increasing frequency by the end of the 21st century, with serious consequences for marine biodiversity and production", says Dr Patrizia Ziveri, ICREA Research Professor at the ICTA-UAB.

Coccolithophores, a very abundant group of marine calcifying phytoplankton, play a major role in the biogeochemical cycles and in the regulation of the global climate. These tiny algae, which measure 2 through calcification and photosynthesis.

So far, few studies have analysed how warming and acidification combined may affect the physiological performance and evolutionary success of the coccolithophore communities. Most studies have been carried out in the laboratory on clones of individual species. ICTA-UAB researchers, in collaboration with the Hellenic Centre for Marine Science Research (HCMR), conducted the experiment in mesocosms using plankton communities collected from naturally nutrient-limited waters of the Eastern Mediterranean Sea (offshore Crete Island, Greece), which included cells of calcifying phytoplankton.

The study, led by Patrizia Ziveri, detailed the behaviour of these algae under conditions of water temperature ? 28°C and a pH of approximately 7.8 units. This is the first time a study like this is conducted in the Eastern Mediterranean, a nutrient-limited region.

"The results highlight a clearly negative effect of thermal stress on coccolithophore cell production and calcification. Likewise, anomalous calcification in this group of phytoplankton was associated with ocean acidification. In addition, for the first time we have registered an interesting increase in the productivity of Rhabdosphaera clavigera, a typical species of the Eastern Mediterranean, in response to acidification", first author of the paper Barbara D'Amario comments. This highlights the importance of looking at species-specific responses to climate change and addressing their specific adaptation mechanisms.

Scientists believe that, due to the progressive increase of CO2 emissions in the atmosphere, the risks derived from ocean warming and acidification will become even more acute in the coming decades, thus changing the plankton communities of the Mediterranean. In the future, a clear understanding of the interactions between the different components of the plankton communities will be essential to better understand the future impact of environmental changes on their adaptation and productivity.

PHILADELPHIA -- (Sept. 30, 2020) -- Researchers at The Wistar Institute unraveled a mechanism employed by chronic lymphocytic leukemia (CLL) cells for their survival. According to the study, published online in Cellular & Molecular Immunology, malignant B cells turn down expression of the STING protein to allow for increased expression of B cell receptor on their surface.

STING is located on the membrane of the endoplasmic reticulum (ER), the cell's protein manufacturing and packaging factory, and is critical for sensing the presence of DNA in the cytoplasm, which can be associated with cell anomalies or infection by viruses and intracellular bacteria. In response to these conditions, STING promotes production of type I interferons and other pro-inflammatory molecules to enhance immunity. Because of this function, STING activation has been proposed as a strategy for cancer and infectious disease immunotherapy.

The lab of Chih-Chi Andrew Hu, Ph.D., professor in Wistar's Immunology, Microenvironment & Metastasis Program, studies the role of STING in the context of B cell differentiation and CLL. They previously discovered that STING activation by agonists induce cell death in normal and malignant B cells.

"Malignant CLL cells typically have low STING levels and strong B cell receptor (BCR) signaling that supports their survival," said Hu, who is senior author on the study. "We explored the role of STING in BCR and B cell differentiation and discovered that reduction in STING expression could contribute to the robust BCR signaling phenotype in CLL cells."

To investigate STING function in B cells, Hu and colleagues generated two genetic mouse models harboring a permanently activated STING mutant (STING V154M) and lacking STING in B cells (B cell-specific STING knockout), respectively. B cells purified from STING V154M mice had reduced BCR expression and signaling upon stimulation, due to activated STING that could efficiently cause destruction of the BCR through a mechanism called ER-associated degradation (ERAD). As a result, activated STING in B cells suppressed formation of plasma cells and antibody production. Conversely, B cells purified from B cell-specific STING knockout mice showed higher levels of BCR and more robust BCR signaling in response to stimulation, and STING deficiency in B cells promoted formation of plasma cells and antibody production in mice.

"Our studies point to a novel B cell-intrinsic role of STING in regulating BCR signaling and plasma cell differentiation," said Chih-Hang Anthony Tang, M.D., Ph.D., a staff scientist in the Hu lab and co-corresponding author of the study. "Our findings also suggest that CLL cells may downregulate STING to promote a stronger BCR signaling to support their survival."

While STING downregulation is also present in other cancer types, it serves the tumor through a different, extrinsic function, reducing the production of type I interferons and preventing activation of antitumor immunity.

Teens who have a larger number of friends may be less likely to suffer from depression later in life, especially women, a new MSU research study has found.

For female adolescents, popularity can lead to increased depression during the teen years, but can provide lasting benefits of fewer depressive symptoms later in life. Teens who reported fewer friends show higher rates of depression in adulthood, found Molly Copeland (pictured left), assistant professor of sociology, who co- authored the article "The Long Arm of Social Integration: Gender, Adolescent Social Networks, and Adult Depressive Symptom Trajectories" with lead author Christina Kamis, a sociology doctoral candidate at Duke University. It was published Sept. 14 in the Journal of Health and Social Behavior.

"Adolescence (is) a sensitive period of early life when structural facets of social relationships can have lasting mental health consequences," wrote Copeland.

Overall, the study found for both men and women, naming few friends predicts higher depressive levels through adolescence into adulthood. But these results are not the same for all genders.

"Compared to boys, girls face additional risks from how others view their social position in adolescence," Copeland wrote.

This current study used data from the National Longitudinal Study of Adolescent to Adult Health, specifically social network data asking students to select up to five male friends and five female friends.

They were also asked to indicate how often they felt depressed. Results from both men and women "follow a U-shaped trajectory of depressive symptoms across this period of the life course, where depressive symptoms are highest in adolescence, decline into early adulthood, and then climb into one's early 30s." However, women experience a steeper decline in symptoms around 18-26 followed by a greater increase in symptoms in their early 30s.

When combined, the data show that for women, being named as a friend by peers is associated with increased depression at age 12 but fewer depressive symptoms in adulthood.

"This result suggests that the association between popularity and greater depressive symptoms reverses with age so that women who were more popular in adolescence have fewer depressive symptoms in their mid-20s compared to less popular peers," Copeland wrote.

But men show no association between popularity and depressive symptoms, the study found, only benefits from naming more friends.

Copeland believes this gender difference suggests that gendered expectations and roles that lead to popularity create stress and strain on adolescent girls that does not apply to boys.

"Gender socialization may lead adolescent friendships to become more taxing to girls if the higher emotional intimacy in female friendships means that popularity creates higher emotion or psychological burdens for girls," Copeland wrote.

But the stress of popularity may give these girls psychosocial skills that are beneficial later in life when dealing with higher education and new jobs.

"Greater sociality may also contribute to a sense of belonging that is psychologically important in adolescent development, setting youth on pathways of lower depressive symptoms."

Copeland joined MSU's Department of Sociology this fall following the completion of her doctoral degree from Duke University. Her research joins social network analysis and medical sociology to examine how social relationships can benefit or introduce risks to health across the life course.

Scientists at the Walter Reed Army Institute for Research and Army Research Laboratory have developed a computer-based training to reduce anger, reactive aggression and hostile attribution bias--the tendency to attribute hostile intent to the actions of others--in ambiguous social conflict situations.

Anger and aggression are common reactions to interpersonal provocations. However, not all provocations lead to these reactions. Past scientific research suggests that the extent to which the victim believes the provocateur acted with malice is key to predicting whether the victim will respond with anger and aggression. The tendency to assume malice in the actions of others is called hostile attribution bias.

Hostile attribution bias and unwarranted anger can jeopardize social bonds, team culture and team performance. It is also linked to post-traumatic stress disorder, depression and other behavioral health concerns.

The novel training, named Hostile Bias Modification Training, exposes trainees to three types of word fragments: ambiguous, aggressive and non-aggressive. Ambiguous fragments could form aggressive or non-aggressive words (KI_ _ could become KILL or KIND), aggressive fragments can only form aggressive words (W_ _PON for WEAPON) and non-aggressive fragments can only form non-aggressive words (FR_ END for FRIEND).

Participants are instructed to only form non-aggressive words and not respond if they cannot think of a non-aggressive word. Subsequently, study participants reacted to vignettes where they were wronged: in some vignettes the intent of the wrongdoer was clearly hostile while in others it was ambiguous. A second study linked these findings to real-world situations by analyzing participants' driving and online social media behavior.

Publishing their findings in the journal Cognitive Therapy and Research, the researchers suggest that HBMT results in significantly lower rates of anger, aggression and hostile attribution bias in response to socially frustrating situations compared to control groups in both laboratory and real-world situations. Notably, HBMT did not alter judgements where the intent of the wrongdoer was clearly hostile.

"Though more research is needed, we believe that HBMT could be effective as both a standalone tool for use at home, in field settings, or in concert with other therapeutic options to help mitigate unwarranted anger and aggression," said Capt. Jeffrey Osgood, a research psychologist at WRAIR and lead author of the study. "We are excited about HBMT's potential to both prevent and treat behavioral health concerns."

While researchers followed participants up to 96 hours after HBMT, further research is needed to determine the maximum durability of the training as well as to study it in clinical populations, identify the optimal dosing strategy and test its use alongside other treatments.

SARS-CoV-2, the virus responsible for COVID-19, has wreaked havoc on health care systems, economies and everyday lives worldwide. Scientists are fighting back with multiple strategies, including vaccines, repurposed drugs developed for other diseases and brand-new therapies. Now, researchers reporting in ACS Central Science have identified small molecules that target a structure within the RNA genome of SARS-CoV-2, interfering with viral gene expression and targeting the RNA for destruction.

The SARS-CoV-2 RNA genome folds into unique shapes that can potentially be targeted by drugs. One region of the RNA, called the frameshifting element (FSE), contains a hairpin and other structures that help the virus translate its genes into proteins. Matthew Disney, Hafeez Haniff, Yuquan Tong and colleagues wondered if they could identify a small-molecule drug that could bind to the hairpin and prevent it from doing its job. They also wanted to see if they could increase the drug's potency by adding a component that would attract an RNA-chopping cellular enzyme to destroy the virus' genome.

The researchers began by conducting microarray experiments to identify small molecules that bind to a specific region of the SARS-CoV-2 FSE hairpin. One molecule, which they named compound 5 (C5), decreased the hairpin's efficiency in helping the virus translate its genes by about 25% in cell culture experiments, reducing the ability of SARS-CoV-2 to make essential proteins. To enhance the potency of C5, the team attached a molecule (called a ribonuclease-targeting chimera, or RIBOTAC) that recruits a human enzyme that degrades the viral RNA. In cultured cells, RIBOTAC increased the potency of C5 by about 10-fold. Although much more work is needed to develop the RIBOTAC-containing compound into a drug, these findings suggest that the SARS-CoV-2 genome can be targeted by small molecules that disrupt its function, the researchers say.

European wildcats, thought to be extinct 50 or so years ago in the Jura mountains, have since recolonised part of their former territory. This resurgence in an area occupied by domestic cats has gone hand-in-hand with genetic crosses between the two species. The hybridisation between wild and domesticated organisms is known to endanger the gene pool of wild species. In a study to be published in the journal Evolutionary Applications, a team of biologists from the University of Geneva (UNIGE), in collaboration with the University of Zurich and the University of Oxford, modelled the interactions between the two species to predict the future of the wildcat in the mountainous region of the Swiss Jura. The different scenarios modelled by the scientists show that within 200 to 300 years --a very short time in evolutionary terms-- hybridisation will entail the irreversible genetic replacement of wildcats, making it impossible to distinguish them from their domestic cousins, as is already the case in Scotland and Hungary.

Although the European wildcat (Felis silvestris) or forest cat was once very common, it fell victim to intensive hunting in the 19th and 20th centuries and to the massive deforestation that cut back its natural habitat, resulting in its disappearance in some parts of Europe. In Switzerland, the wildcat was deemed practically extinct, with no trace found for 25 years from 1943 to 1968. Thanks to a federal law that has protected the animal since 1962, the wildcat has recolonised the forests and meadows in the Jura range, where it lives side-by-side with the domestic cat (Felis catus) in particular. Although considered two species --or as different subspecies by some-- wildcats and domestic cats can interbreed and have hybrid, fertile kittens. These have the genome of both species and may give birth to offspring carrying the recombinant genes of each species. These hybridisations pose a new threat to the wildcat, since they prompt gene transfers based on a mechanism known as genetic introgression. This mechanism can quickly result in the dissemination of the genes of the more abundant species in the genome of the rarer species. The risk exists in the short term that the genome of the domestic cat will gradually replace the gene of the wildcat, which is markedly less plentiful than its domestic cousin, leading to the extinction of the wildcat.

Recolonising the territory

Scientists from UNIGE and the University of Zurich demonstrated in earlier studies that there is a greater introgression of the wildcat genome by the domestic cat genes than vice versa. The demographic and territorial expansion of wildcats over the last 50 years was identified as the most likely cause of these introgressions, which tallies with observations in the field. This conclusion was reached using bioinformatic simulation models factoring in ecological and genetic characteristics. It was estimated that about 5-10% of contacts between wild and domestic cats produced hybrid kittens. Following these discoveries, the computer model was refined in order to make projections and define the urgency for intervening and preserving the species.

The only solution: stop crossbreeding

The variable factors in the model incorporated in the new article, whose last author is Mathias Currat, senior researcher at the UNIGE Department of Genetics and Evolution, are the hybridisation rate, competition for resources in the environment and the size of the populations. Irrespective of the scenario put forward while acting on these variables, a very strong introgression of the domestic cat's genome into the genome of the wildcat is predicted. Mathias sounds a warning: "This is strongest with population sizes comparable to today's, but is still very high even if we consider more favourable conditions for the wildcat, such as an increase in its population size or a competitive advantage over the domestic cat in the regions where they coexist." Juan Montoya-Burgos, laboratory director in the Department of Genetics and Evolution at UNIGE, and co-author of the study, warns: "The model leads to an irreversible genetic replacement resulting in the ultimate disappearance of the wildcat. Only the end of crossbreeding between the two species predicts the conservation of the wild species."

Action needed now

It follows that the wildcat remains an endangered species in spite of the positive signs of its recent expansion. The dynamic model put forward in the UNIGE study, which combines the demographic and spatial growth of the wildcat populations, can be used to predict the future of the species. Based on the various scenarios, wildcats will be assimilated to domestic cats in as little as 200 to 300 years, as is already the case in Scotland and Hungary. "A hybridisation event has a proportionally much greater impact on the wildcat population, which consists of a few hundred individuals, than in the domestic population, which numbers over one million individuals in Switzerland", points out Mathias Currat.

One initiative suggested by the authors is to drastically reduce the opportunities for hybridisation on the fringes of the wildcat territories. Campaigns to sterilise domestic cats living near farms or close to forests are just one of the proposals. Females should be the primary target since domestic females mate more readily with male wildcats than male domestic cats with wild females. "Early interventions are likely to be less costly both financially and in environmental terms. If we stay passive, the threat to weigh on wildcats in the Jura risks being irreversible," concludes Juan Montoya-Burgos.

Girls - but not boys - who participate actively in school sports activities in middle childhood show improved behaviour and attentiveness in early adolescence, suggests a new Canadian study published in Preventative Medicine.

"Girls who do regular extracurricular sports between ages 6 and 10 show fewer symptoms of attention-deficit/hyperactivity disorder (ADHD) at age 12, compared to girls who seldom do," said Linda Pagani, a professor at Université de Montréal's School of Psychoeducation.

"Surprisingly, however, boys do not appear to gain any behavioural benefit from sustained involvement in sports during middle childhood," said Pagani, who led the study co-authored by her students Marie-Josée Harbec and Geneviève Fortin and McGill University associate medical professor Tracie Barnett.

As the team prepared their research, "it was unclear to what extent organized physical activity is beneficial for children with ADHD symptoms," recalled Pagani.

"Past studies have varied widely in quality, thus blurring the true association between sport and behavioural development." She added: "On top of that, "past research has not acknowledged that boys and girls are different in how they present ADHD symptoms."

A chance to get organized

ADHD harms children's ability to process information and learn at school, Pagani explained. Sport helps young people develop life skills and supportive relationships with their peers and adults. It offers a chance to get organized under some form of adult influence or supervision.

"Thus, from a public-health perspective, extracurricular sport has the potential to be a positive, non-stigmatizing and engaging approach to promote psychological well-being and could thus be viewed as behaviour therapy for youth with ADHD," Pagani said.

"Sports are especially beneficial if they begin in early childhood. And so, since using concentration and interpersonal skills are essential elements of sport, in our study we undertook to examine whether it would result in reductions in ADHD symptoms over the long term."

Pagani and her team came to their conclusions after examining data from a Quebec cohort of children born in 1997 and 1998, part of the Quebec Longitudinal Study of Child Development coordinated by the Institut de la statistique du Québec.

Parents of the 991 girls and 1,006 boys in the study reported on whether their sons and daughters were in an extracurricular physical activity that required a coach or instructor between ages 6 and 10. At age 12 years, teachers rated the children's behaviour compared to their classmates. Pagani's team then analyzed the data to identify any significant link between sustained participation and later ADHD symptoms, discarding many possible confounding factors.

"Our goal was to eliminate any pre-existing conditions of the children or families that could throw a different light on our results," said Pagani.

'Boys more impulsive'

Why do girls with ADHD benefit from sports, but not boys?

"In childhood, boys with ADHD are more impulsive and more motor-skilled than girls -- as a result, boys are more likely to receive medication for their ADHD, so faster diagnosis and treatment for boys in middle childhood could diminish the detectable benefits of sport," Pagani said. "They might be there; they're just harder to tease out."

"In girls, on the other hand, ADHD is more likely to go undetected -- and girls' difficulties may be even more tolerated at home and in school. Parents of boys, by contrast, might be more inclined to enroll them in sports and other physical activities to help them."

She added: "We know that sporting activities have other numerous benefits for mental health of all children. However, for reducing ADHD symptoms, middle childhood sports in elementary school seem more noteworthy for girls."

That's why structured extracurricular activities that demand physical skill and effort under the supervision of a coach or instructor could be valuable to any official policy aimed at promoting behavioral development, the UdeM researchers maintain.

Concluded Pagani: "Sports activities in early childhood can help girls develop essential social skills that will be useful later and ultimately play a key role in their personal, financial and economic success."

A cooler full of fish might not be the only thing anglers bring back from a trip to the lake. Unknowingly, they may also be transporting small aquatic "hitchhikers" that attach themselves to boats, motors -- and even fishing gear -- when moving between bodies of water.

Considerable research shows that aquatic invasive species can completely transform ecosystems by introducing disease, out-competing and eating native species, altering food webs, changing physical habitat, devastating water-delivery systems and damaging economies. Furthermore, once established, eradication of nuisance species is near impossible, and management can be extremely difficult and costly.

Although preventative measures have been enacted to reduce their introduction and spread, such as mandatory watercraft inspections, educational programs and even dogs trained in sniffing out invasive species, these aquatic stowaways still manage to find their way into new water bodies around the country.

One of the many challenges is identifying how these species spread through human movement. A new University of Washington study uses passive data from a fishing technology company to model the movement of anglers and predict where aquatic invasives may be spreading. The findings were published Sept. 2 in the journal NeoBiota.

"Focusing on anglers allows us to look at a population that uses a wide range of gear on the water; therefore, they have the potential to move a very wide range of species," said Rachel Fricke, a graduate student at the UW School of Aquatic and Fishery Sciences. Fricke's research on invasive species is a continuation of her undergraduate capstone project which she also completed at the school.

The researchers used data provided by ReelSonar, the Seattle-based developer of the pocket-sized fish finder iBobber. The iBobber syncs with an angler's smart device and collects multiple pertinent data points, including fishing location. To date, over five million locations have been recorded from around the world.

"In the past, ecologists have done an incredible job extracting big datasets from the web without necessarily working with the organizations who collected the data in the first place," said co-author Julian Olden, a professor of aquatic and fishery science. "This is to be expected, but I believe that real creativity in the future will come from more authentic collaborations where both ideas and products are co-generated."

Previous studies relied on optional online forms, requiring anglers to log fishing trips from each location they visited. With ReelSonar's passive data, these points are generated automatically, offering researchers an exciting opportunity to further understand where people are moving and when.

The authors specifically looked at location data in the United States and narrowed it down to identify individual trips made by anglers. By quantifying geographic patterns of fishing activities and assessing how these patterns change seasonally, the authors explored angler behavior (fishing frequency and distance traveled) between sites.

"We were predominantly interested in where people were fishing and the amount of time between their trips to different lakes," said Fricke. "The length of time determines the types of species anglers unintentionally move, as each species has very different survival rates out of the water."

The authors were also interested in the routes people were using to travel between fishing locations.

What they found was the vast majority of road distances traveled are over small spatial scales. Most anglers are staying near urban areas, but fishing multiple different lakes or rivers in a small radius over a short amount of time. The authors then focused on "invasion hubs," water bodies that have many linkages via human movement to other nearby water bodies. The timeframe of these movements, which was mostly two days or fewer, fell well within the out-of-water survival threshold for the six invasive species identified in the study.

"Boiled down, people are moving a lot and they're moving quickly from one place to the next, which has the potential to move a number of different invasive species," said Fricke. "I don't think we need to change the preventative measures that we use in light of this data, but it does enable us to better locate those preventative measures in space and time."

Identifying highly trafficked roads near invasion hubs can be valuable from a management perspective and can help influence where roadside inspection stations and educational signage are placed.

"If we see points in these data where invasion hubs exist and where resources are not being allocated, this gives managers the opportunity to identify and implement required boat cleaning and boat inspection stations in those locations," said Fricke. "This kind of data offers a ripe opportunity to reassess where we're enacting preventative measures and to be more strategic about where we do that."

Loved or hated, the humble oat could be the new superfood for cancer patients as international research shows a diet rich in fibre could significantly reduce radiation-induced gut inflammation.

Conducted by the University of Gothenburg, Lund University and the University of South Australia, the preclinical study found that dietary oat bran can offset chronic gastrointestinal damage caused by radiotherapy, contradicting long-held clinical recommendations.

Gastroenterology and oncology researcher UniSA's Dr Andrea Stringer says the research provides critical new insights for radiology patients.

"Cancer patients are often advised to follow a restricted fibre diet. This is because a diet high in fibre is believed to exacerbate bloating and diarrhoea - both common side effects of radiotherapy," Dr Stringer says.

"Yet, this advice is not unequivocally evidence-based, with insufficient fibre potentially being counterproductive and exacerbating gastrointestinal toxicity.

"Our study compared the effects of high-fibre and no-fibre diets, finding that a fibre-free diet is actually worse for subjects undergoing radiotherapy treatment.

"A diet without fibre generates inflammatory cytokines which are present for a long time following radiation, resulting in increased inflammation of the digestive system.

"Conversely, a fibre-rich diet decreases the presence of cytokines to reduce radiation-induced inflammation, both in the short and the long term."

Intestinal issues following radiotherapy are problematic for many cancer survivors.

"In Europe, approximately one million pelvic-organ cancer survivors suffer from compromised intestinal health due to radiation-induced gastrointestinal symptoms," Dr Stringer says.

"This is also commonplace in Australia and around the world with no immediate cure or effective treatment.

"If we can prevent some of inflammation resulting from radiation simply by adjusting dietary fibre levels, we could improve long-term, and possibly life-long, intestinal health among cancer survivors."

Climate warming will alter marine community compositions as species are expected to shift poleward, significantly impacting the Arctic marine ecosystem.

The biodiversity of marine communities in the Pacific Arctic under future climate change scenarios highlights profound changes relative to their present patterns. Alterations in marine species distributions in response to warming and sea ice reduction are likely to increase the susceptibility and vulnerability of Arctic ecosystems. The findings, published by Hokkaido University researchers in the journal Science of the Total Environment, also suggest that there will be potential impacts on the ecosystem function and services.

Fisheries oceanographer Irene Alabia of Hokkaido University's Arctic Research Center along with colleagues in Japan and the US investigated how future climate changes will impact the marine biodiversity in the Bering and Chukchi Seas. These seas extend from Alaska to Russia in the northern Pacific and southern Arctic oceans.

"This area forms a 'biogeographical transition zone': a biodiversity-rich region covering two distinct areas with specific features that encourage the coexistence of species living at or close to their distribution limits," explains Alabia. "These zones are vulnerable to climate warming, and climatic disruptions can create favorable conditions for the shift of warm-water species into previously colder-water zones."

Scientists are interested in understanding how species in biogeographical transition zones are responding to climate changes and other human impacts. This information could help in conservation planning, fisheries management, and in studying the role of evolutionary history in shaping currently existing communities.

Alabia and her team mapped the present and future spatial distributions of 26 fish and invertebrate species in the Bering and Chukchi Seas. Using species records, sea surface temperature, and sea ice concentration data, the authors developed species distribution models to predict the distributional ranges under the present-day (1993-2017) and future (2026-2100) climate conditions. From the model outputs, the changes in species richness and compositional diversity in terms of species' phylogeny and functional traits between time periods and across contrasting levels of warming were elucidated.

The findings suggest that larger, longer-lived and more predatory fish and invertebrates will expand their ranges towards the pole in response to warming waters and sea ice free conditions by the end of the 21st century. These poleward shifts could alter the structure, composition and functions of future Arctic communities, which are currently dominated by smaller and short-lived species. The future species pool in the Arctic waters will also have more similar functions within the ecosystem, impacting regional food webs. It is also likely that there will be considerable socioeconomic impacts, as commercially important species shift northwards, which could increase operational fishing costs.

"These projected impacts are expected to raise challenges for ocean governance, conservation and resource management of shifting fisheries," says Alabia. "Our results provided glimpses of potential futures of the Arctic marine ecosystems, nonetheless, and some of these ecological shifts are already being documented. As such this highlights the need for continued monitoring and improving climate-ready strategies to buffer climate change impacts and maintain the integrity and functioning of vulnerable ecosystems."

(Vienna, 29 September 2020) An antibody for treating advanced prostate cancer improves progression-free survival in patients with metastasised, castration-resistant prostate cancer. This is the finding of the long-term analyses of an international phase 3 clinical trial, recently published in the leading journal European Urology. The study showed that overall survival was 2 - 3 times higher than in the placebo arm.

Ipilimumab is a humanised monoclonal IgG1 antibody that is active against CTLA-4. CTLA-4 is a molecule that controls part of the immune system by down-regulating it. "Cancer cells can evade the endogenous defence of the immune system by deactivating it. An antibody that targets CTLA-4, a so-called checkpoint inhibitor (CPI), can block this deactivation, thereby reactivating the immune system once again. This reactivated immune response can then help the body to destroy cancer cells," explains oncologist Michael Krainer from the Department of Medicine I at MedUni Vienna/Vienna General Hospital and from the Comprehensive Cancer Center (CCC). The internationally renowned "Urological Tumours" working group from the division led by Krainer was invited to participate in the first global clinical phase 3 trial of a CPI in prostate cancer CA184-043, the long-term results of which have now been published in European Urology, the world's most influential urology journal.

The recent trial included a total of 799 men. It was conducted globally: in the USA, Canada, South America, Australia and European countries. Patients were randomised in a 1:1 ratio to receive bone metastasis radiotherapy (a single 8 Gy fraction) followed by either ipilimumab 10 mg/kg or a placebo every three weeks via up to four injections. Although in the first planned analysis, the survival advantage in the treated group was present it was not significant, whereas the recent analysis shows that long-term survival after 3, 4 and 5 years is two - three times higher in the immunotherapy arm as opposed to the placebo arm.

Ipilimumab is already licensed by the European Medicines Agency to treat melanoma, lung cancer and bladder cancer. However, there is still a lack of reliable data for approval to treat prostate cancer, since the first planned analysis did not show any significant survival advantage. In the light of the new long-term results, Krainer says: "Immunotherapy is highly promising and can be used, for example, when chemotherapy options have been exhausted or are undesirable. It can also be expedient to start it at an early stage, since any treatment is more effective if there is little cancer present and the patient is in good general health. We are the first group in Austria to gain such valuable experience and we are now attempting to incorporate immunotherapy into the treatment in the context of international clinical trials."

The working group will soon start on two study protocols using immunotherapy before a chemotherapy that is currently the standard treatment for patients with castration-resistant prostate cancer.