Earth

A ground-breaking method to label and track manufactured nano-plastics could signal a paradigm shift in how we understand and care for environments, finds a new study.

Nano-plastics are particles of at least one dimension below one μm. While there has been growing awareness of the dangers of visible plastic pollution to marine life, nano-plastics are thought to be even more dangerous as unseen, smaller animals and fish can ingest them.

Nano-plastics are suspected of being released into the environment directly by commercial products and by the breakdown of larger pieces of plastic litter.

In a study published by the journal Communications Materials, researchers from the University of Surrey detail a new one-step polymerization method to label nano-polystyrene directly on the carbon backbone of plastic. The new simple method uses 14C-styrene and requires minimal reagents and equipment to create nano-particles in a wide range of sizes for use in simulated lab environments.

The team has used their new method to produce and investigate the behaviour of nano-plastics at low concentrations in a variety of scenarios - including in bivalve mollusc.

Dr Maya Al Sid Cheikh, co-author of the study and Lecturer in Analytical Chemistry at the University of Surrey, said:

"The truth is that the scientific community knows little about the effects and behaviour of nano-plastics in our environment because it's extraordinarily difficult to detect, track and measure such minute particles.

"Our new, simple method is a step in the right direction for correcting this knowledge gap as it allows researchers to replicate scenarios in which commercially produced nano-particles have customarily gone unnoticed."

Scientists from the School of Biomedicine of Far Eastern Federal University (FEFU) with colleagues from Italy, Spain, Romania, and Sweden suggest a way to protect the brain and minimize neurodegenerative processes after concussion head injuries in the presence of extensive previous sleep deprivation. This methodology is especially important given the retirement-age increase that has recently become an international trend. A related article appears in the Progress in Brain Research journal.

The team have modeled brain dysfunctions after a minor head injury in the presence of extensive previous sleep deprivation, identified the hormones and proteins that affect the development of neurogenerative processes, and suggested compensating for them with target drug delivery using TiO2 nanocrystals. The new therapeutic method will protect the neurons and minimize the loss of cognitive functions and degradation of brain tissue.

"Brain dysfunctions of this type are typical for military personnel engaged in special operations and suffering from long sleep deprivation. In situations like this, even a relatively minor head injury can cause the development of complex pathophysiological mechanisms that can negatively affect health. However, such dysfunctions are even more widely spread among middle-aged people with CNS vascular diseases and initial stages of cerebrovascular disturbance--the conditions that could lead to a stroke, if left untreated. In these patients, a concussion or a hypertensive crisis caused by high blood pressure might bring about neurogenerative processes leading to progressive loss of cognitive functions," explains Igor Bryukhovetskiy, the Head of the Laboratory of Molecular and Cellular Neurobiology, Department of Fundamental Medicine of the School of Biomedicine at FEFU.

According to the scientist, about 20% of adults all over the world suffer from sleep disturbances that can cause reduced activity and sleepiness during the day and negatively affect one's decision-making abilities. Among these people, there is military personnel, as well as night-shift workers, including health care specialists. Sleep deprivation increase the risk of neurogenerative processes even in case of a minor head injury.

Studies confirm that both head injuries and long sleep deprivation, as well as a combination of these two factors, lead to reduced production of alpha-melanocyte-stimulating hormone and the so-called brain-derived neurotrophic factor, a protein coded by the BDNF gene. The gene also stimulates and supports neuron development. However, that is possible to compensate the lack of these substances.

The team suggest delivering titanium dioxide capsules with cerebrolysin (a combination of several proteins and peptide fragments) and alpha-melanocyte-stimulating hormone directly to a patient's brain. This procedure comes along with the transplantation of mesenchymal stem cells from the patient's bone marrow to their brain. The new method could help protect brain neurons and limit neurological damage and cognitive dysfunction (i.e. the loss of existing knowledge and skills and inability to acquire new ones).

According to the researchers, titanium dioxide secures the best therapeutic effect of the delivered drugs and reduces the production of the very important extracellular protein called cachectin or tumor necrosis factor-alpha. Its misregulation is associated with various neurodegenerative and autoimmune conditions, such as Alzheimer's disease and psoriasis, respectively.

The team believes in the importance of their work given the retirement-age increase all over the world. The aging of the population in some countries in Europe, Asia, and North America combined with early onsets of hypertension and glucose tolerance malfunction in relatively young people add to this process. To respond to this trend and support people's labor efficiency and cognitive functions, medicine has to develop preventive measures, such as new neuroprotective and organ-saving technologies.

PROVIDENCE, R.I. [Brown University] -- After several decades of improvement, inequality in infant health is once again on the rise in the United States, a pair of Brown University researchers has found.

Between 1989 and 2010, the health gap between infants born to the most socially advantaged mothers -- those who are married, highly educated and white -- and infants born to the least socially advantaged mothers -- those who are unmarried, without a high school diploma and Black -- steadily decreased. But according to a new study, that trend began to reverse in 2010, creating an ever-widening gulf that could last for generations.

"Lots of Americans view the U.S. as a land of equal opportunity where hard work pays off," Emily Rauscher, an associate professor of sociology at Brown. "But equality of opportunity is fundamentally impossible to achieve as long as there is inequality in infant health. When babies are born in under-resourced communities, they are more likely to be born underweight or malnourished. They're already at a disadvantage before they've even had an opportunity to do anything in the world."

Rauscher conducted the study with David Enrique Rangel, an assistant professor of education -- both are affiliated with Brown's Population Studies and Training Center. The results were published in the journal Social Science & Medicine -- Population Health.

The coauthors said they were motivated to investigate the trend in infant health inequality after the possibility of a shift came to their attention in conducting research on how maternal education affects infant health. As they combined data from Rauscher's previous research on the effects of parent education levels on infant health with existing data on the effects of maternal race and ethnicity on infant health, they noticed that the data suggested a recent increase in inequality -- a worrisome departure from the decades-long decline in inequality identified by Brown economist Anna Aizer in an influential 2014 paper.

The trend is a concern, Rauscher and Rangel explained, because multiple studies have shown that when infants are born underweight or more than three weeks before their due date, they may face health complications that could affect mental, physical and economic well-being for years to come. Those health complications are more likely to occur in infants born to mothers who face social and economic disadvantages, studies show, because they are more likely to experience high levels of stress, live in areas with limited access to affordable, nutritious food and come into contact with harmful chemicals in places where they live and work.

"The social conditions of living in an under-resourced community -- more exposure to carcinogens, less access to healthy food, more stress -- result in poorer infant health outcomes, like issues with cognitive development," Rangel said. "That could result in a child struggling in school or an adult struggling to find a job. That could mean a child exhibiting externalizing behaviors -- lashing out at peers."

To confirm that their preliminary findings were correct, the authors analyzed three decades of data from the National Vitality Statistics System, a birth registry that records key infant health statistics and maternal race, marital status and education level. Like Aizer, they found that between 1989 and 2010, health disparities between infants born to mothers at opposite ends of the socioeconomic spectrum had gradually narrowed, leading to better health outcomes for infants born in more disadvantaged communities.

"One of the major reasons why inequality decreased in these decades was because there was an increase in knowledge about what led to good fetal health outcomes," Rauscher said. "Doctors have learned that things like folic acid supplements and routine checkups can make a big difference in infant health. Nowadays, almost every OBGYN in every town has an MRI machine, which allows them to do the ultrasounds that help them catch slow growth early. They know that diabetes, pre-pregnancy hypertension and smoking during pregnancy are all major risk factors."

However, the researchers found that that decades-long pattern of improvement seems to have reversed course in the last few years. Their data show that infant health inequality in the U.S. seems to have grown steadily over the last few years in concert with increasing income inequality, which has now reached a 50-year high. Over the last decade, the researchers observed that gaps in health between Black and white infants remained relatively stable. But health inequality increased between infants born to married and unmarried mothers and between mothers at opposite ends of the educational attainment spectrum.

For example, Rauscher said, the number of pre-term babies born to married mothers increased by 0.6% per decade before 2010, but in the 2010s, it decreased by 1.6%. Conversely, the number of underweight infants born to unmarried mothers decreased by about 0.7% per decade before 2010 but increased by 1.1% per decade after that. In other words, at the same time that health risks improved for infants born to married mothers, they worsened for infants born to unmarried mothers.

The researchers found that the steepest growth in infant health inequality was between mothers who had graduated from college and mothers who did not finish high school. In the two decades before 2010, the health of infants born to mothers with no high school degree remained fairly stable. But after 2010, rates of low birth weight increased by 1.4%. In contrast, before 2010, mothers who had a college degree experienced slight increases in underweight and preterm births -- but after 2010, very low birth weight and pre-term births among college-educated mothers declined by 0.1% and 1.7%, respectively.

"The fact that we found the steepest increase in inequality when we isolated for education level suggests to us that moms without a high school degree have become increasingly marginalized in American society," Rauscher said. "That could be because the population of Americans without a high school degree is becoming smaller and smaller -- so as education levels rise, those with the lowest levels of education face more of a disadvantage in every respect."

Rauscher and Rangel found that the biggest disparity in infant health outcomes was between those whose mothers were white, married and college-educated -- in other words, those who had a socioeconomic advantage due to a combination of their race, marital status and education -- and those whose mothers were Black, unmarried and without a high school degree. In the former group, the rate of low birth weight had been increasing by about 0.3% per decade before 2010, but it decreased by about 0.1% after 2010. In the latter group, the rate of low birth weight declined by about 1% per decade in the 1990s and 2000s, but after 2010, the rate reversed course and increased at a rate of about 1.5% per decade.

The increase in inequality shows that improved medical knowledge alone can't drive away disparities in health outcomes, Rauscher said. The reversal of fortune in 2010 came on the heels of the Great Recession, which disproportionately impacted the most marginalized Americans, including people of color and people living below the poverty line, according to multiple economic studies -- evidence that infant health can't improve until the U.S. solves major systemic issues such as food insecurity, the high cost of health care and homelessness, the researchers said.

"It's really valuable for pregnant women to go to the doctor regularly, but going to the doctor won't solve everything," Rangel said. "We know that factors like stress, poor nutrition and exposure to pollution can have negative implications for fetal development. But doctors can't wave a magic wand and give mothers secure housing or move them out of food deserts."

Both Rauscher and Rangel said they hope their data will prompt policymakers at all levels to consider large-scale reforms that would improve infant health inequality. School districts, for example, should consider improving academic support for disadvantaged high school students to minimize dropout rates, they said, and federal leaders should ponder the economic advantages of implementing a universal basic income.

"To see positive changes, there are going to have to be huge social interventions," Rangel said. "It's more than making sure pregnant women get to the doctor within six weeks. It's providing a complete social safety net, which not only helps disadvantaged mothers stay on their feet but also means the next generation is happier and healthier than the last."

Social media influencers vaping glamorously into their social media feeds are often not doing so for free. And new research suggests that calling out their pay-to-play posts as advertisements in a plain, obvious way might have an impact on young people.

A study of 200 teens and young adults used eye-tracking technology to determine that tagging vaping-related influencer Instagram posts with #ad or #sponsored was effective in grabbing attention. The study appears online in the Journal of Health Communication.

"The e-cigarette industry is paying these social media celebrities to do what they do best -- shape young people's behavior. And our study gives us some hope that placing labels on these posts might be an effective tool to discourage young people from picking up a harmful habit," said Liz Klein, the study's lead author and an associate professor of health behavior and health promotion at The Ohio State University.

"These people are called 'influencers' for a reason. They get an amazing amount of attention, particularly from teens and young adults, and when they post about e-cigarettes they typically make zero reference to the fact they've been paid by the industry to make these posts," she said.

Industry-backed social media activity is considered commercial sponsorship and technically should come with a disclosure in order to comply with Federal Trade Commission regulations, Klein said. And since the study was done, Instagram and Facebook have banned paid influencer posts that promote vaping and other tobacco use on their platforms.

Practically speaking, however, most influencers aren't tagging their e-cigarette posts as advertisements or sponsored content and there have been no details provided on how the bans instituted by the platforms are being enforced, the researchers said.

To understand how attention-grabbing the labels would be, the researchers studied the participants' viewing patterns while the teens and young adults looked at their personal Instagram feeds interspersed with influencer posts about vaping.

Study participants spent an average of 6.6 seconds viewing e-cigarette influencer posts, and about 3.1 seconds on the area labeled #ad, compared to 2.2 seconds on the area of interest labeled #sponsored. Viewers spent about 2 seconds longer -- an average of 8.4 seconds -- on unlabeled influencer posts about vaping.

While the study didn't explore how these observations might impact behavior, the findings support the idea that labels do capture attention, and that's an important step, the researchers said.

"There's no dispute that influencer advertising for harmful products is a problem -- the question is what to do about it. Any policy response should be based on evidence. This is a first step in figuring out whether requiring paid influencers to use hashtags like #sponsored or #ads is likely to be effective," said study co-author Micah Berman, associate professor of law and public health at Ohio State.

"What we found here is that people are noticing the hashtags, particularly -- and somewhat to our surprise -- the #ad one. The next steps include figuring out what people think of these hashtags and whether they have any impact on behaviors."

Previous research has established that labeling advertising as such can have a negative impact on the perceived credibility of messages, Klein said, so it's important for those working to decrease the use of e-cigarettes to figure out how best to leverage that in harm-prevention efforts.

"Product placement, when it's not subtle, can turn people off. But when it's more subtle, and disguised as non-advertising content, young consumers are likely to be more vulnerable to the messaging," she said. "They're essentially being manipulated."

University of Victoria biologists have discovered how some corals managed to survive a globally unprecedented heatwave, in a first-ever study that provides new hope for the long-term survival of coral reefs in the face of climate change.

"The devastating effects of climate change on coral reefs are well known. Finding ways to boost coral survival through marine heatwaves is crucial if coral reefs are to endure the coming decades of climate change," says UVic marine biologist Julia Baum, the study's senior author.

Published today in Nature Communications, the study presents the discoveries made by the international research team as they tracked hundreds of coral colonies on reefs around Christmas Island (Kiritimati), throughout the 2015-2016 El Niño. Heat stress from that El Niño triggered the third-ever global coral bleaching event, causing mass coral bleaching and mortality on reefs around the world. Its epicentre was Christmas Island, where the heatwave lasted an unprecedented 10 months.

Worldwide, coral reef fisheries are worth US$6.8 billion annually, and are a vital source of food and income for hundreds of millions of people in tropical island nations. In the lead-up to the United Nations Decade of Ocean Science for Sustainable Development (2021-2030), there is a renewed and global call to reverse the cycle of decline in ocean health.

"Understanding how some corals can survive prolonged heatwaves could provide an opportunity to mitigate the impact of marine heatwaves on coral reefs, allowing us to buy time as we work to limit greenhouse gas emissions," says Danielle Claar, who led the study as a UVic doctoral student and is now a postdoctoral researcher at the University of Washington.

Climate change threatens the world's coral reefs because corals are highly sensitive to the temperature of their surrounding waters. During a heatwave, corals release the algae that live in their tissues and produce food for them, causing the coral to turn completely white--a phenomenon known as coral bleaching. Prolonged bleaching often causes corals to die from starvation. If they can reclaim their food source within a few weeks, they can usually recover.

To date, coral recovery from bleaching has only ever been observed after heat stress subsides. With global climate models predicting that heatwaves will continue to increase in both frequency and duration, a coral's ability to recover its food source during a prolonged heatwave is essential to its survival.

"Observing corals recovering from bleaching while still baking in hot waters is a game changer," says Baum.

Baum adds that corals only exhibited this capacity if they were not also exposed to other types of human-caused stressors, such as water pollution. Until now it's been unclear if local reef management could help improve corals chances of surviving climate change. "We've found a glimmer of hope that protection from local stressors can help corals," says Baum.

"Although this pathway to survival may not be open to all corals or in all conditions, it demonstrates an innovative strategy for survival that could be leveraged by conservationists to support coral survival," adds Claar.

Epileptic spasms are a type of brief seizures that are the hallmark of catastrophic seizure disorders, which are characterized by severe cognitive and motor deficits. Researchers from Baylor College of Medicine and Texas Children's Hospital now provide evidence that epileptic spasms originate from the pyramidal cells in the deep layers of the neocortex. Further, they uncovered a novel neurophysiological phenomenon that explains how cortical neurons generate spasms. This is also the first study to reveal a hitherto unknown relationship between a normal brain state, like sleep, and spasms. The study was recently published in the Annals of Neurology.

An English physician first described epileptic spasms in the mid-1800s. Since then, neuroscientists have tried to understand the cellular and mechanistic origins of epileptic spasms.

"We are excited to finally have some fundamental insights into where and how spasms originate in the brain," lead author, Dr. John Swann, who is a professor at Baylor College of Medicine, director of the Cain Foundation Laboratories for Pediatric Neurology, and co-director of the Jan and Dan Duncan Neurological Research Institute at Texas Children's, said. "Our findings also reveal a previously unappreciated interplay between wake/sleep brain states and how spasms are generated which opens up new avenues for the development of desperately-needed interventional therapies."

Hyper-activation of pyramidal cells in the brain neocortex generates epileptic spasms

To understand the underlying neurophysiological basis of spasms, Dr. Chih-hong Lee, a former graduate student in the Swann lab (currently at the Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taiwan), induced severe spasms in rodents using the well-established tetrodotoxin (TTX) model which he developed in 2008. He induced spasms by chronically infusing TTX, a sodium channel blocker, in the developing neocortex of rats and used state-of-the art electrophysiological techniques to simultaneously record and analyze neural activity from various brain regions before and during spasms.

The team found epileptic spasms were generated by the pyramidal cells in the deep layer V of the neocortex. This is an important part of the frontal lobe, critical for information processing and higher-order brain functions, such as cognition, sensory perception, generation of motor commands, spatial reasoning and language. Specific activation of only the pyramidal cells of the neocortex also led to marked increases in the occurrence of spasms, supporting the idea that this specific group of neurons is responsible for generating the spasms.

EEG patterns before and at the onset of spasms resemble NREM sleep brain states

After discovering hyper-excitability of pyramidal cells in the neocortex as the source of epileptic spasms, the researchers next focused on how this group of neurons generated epileptic spasms.

"To our great surprise, we observed a dramatic pause in the neuronal activity across the cortex immediately prior to the onset of spasms. This was completely unexpected and unlike what would be anticipated during seizures," Swann said. "This activity pattern closely resembled a phase of the non-rapid eye movement (NREM) sleep cycle. During NREM sleep, a person or animal's brain generates rhythmic slow oscillations and simultaneously cortical neurons undergo alternating 'down' states when neurons stop firing followed by an 'up' state, when the neurons become collectively active. This rhythmic wave continues over and over again during NREM sleep. We found this observation especially intriguing because it is well-documented that many West syndrome patients experience spasms during periods of drowsiness just before sleeping or upon waking up."

The similarity in brain activity as measured using electroencephalogram (EEG) just prior to the onset of, and during spasms, and NREM sleep raised the possibility that the mechanisms that underlie NREM sleep state could predispose the neocortex to generate spasms.

"Upon testing this possibility further, we found the pre-spasm pause closely resembled and shared at least four features with the 'down' states of NREM sleep. Moreover, recordings from epileptic animals also showed the subsequent 'up' states were abnormally intense compared to those in control animals, and these hyperactive 'up' states were actually sufficient to initiate a spasm," Swann said.

Based on these results, the team concluded the activity of the pyramidal cells in the neocortex before and during a spasm closely mirror slow oscillation waves that are common during NREM sleep, with a slight twist - animals prone to spasms had much more intense or exaggerated activity during the 'up' state, which triggered subsequent spasms.

Finally, upon long-term observation of brain activity of these epileptic animals, researchers concluded this 'up' and 'down' sequence of network slow oscillations becomes much more frequent just prior to the onset of spasms. They observed identical EEG patterns, including an increasing crescendo of 'up and down' sequences in the brains of four patients with infantile spasms right before the appearance of spasms, validating their observations in rodents.

"We are hopeful that with our discovery of the fundamental neural circuits and physiological mechanisms involved in spasms, better prognostic tools and therapeutic approaches can be developed for all affected patients, irrespective of their age or the underlying condition from which they suffer," Swann added. "Our results also open many interesting new directions for research to dissect the relationship between normal brain states and epilepsy. For instance, since the slow wave stage of NREM sleep cycle is known to be crucial for optimal learning, memory consolidation and storage, and higher-order executive decisions, we can now begin to address how these processes are impacted by epileptic spasms in the developing brains of children and adults."

Injury or disease that afflicts a relatively small number of brain cells causes a chain reaction that stops activity across a vast network of neural circuits, according to new research from Oregon Health & Science University.

The findings, published today in the journal Neuron, may help to explain why people can suffer from temporary but severe loss of cognitive function in cases of traumatic brain injury or disease.

"Even the so-called bystander neurons that aren't injured or diseased can sense there's been an injury and radically change their function," said senior author Marc Freeman, Ph.D., director of the Vollum Institute at OHSU. "That means that it's not just the broken neurons that are affected when you have a nervous system injury - it's maybe all of the neurons."

Researchers made the discovery working with the fruit fly Drosophila, which despite its tiny size is a well-established model for neural networks in people. They zeroed in on the axon, the threadlike portion of a nerve cell that transmits signals within the nervous system. To simulate the damage that might occur in a discrete head injury, researchers snipped a small number of axons in a larger bundle.

They found that the relatively small injury rippled out beyond the severed axons, suppressing sensory signals among neurons that weren't directly damaged at all.

"A small injury can cause the whole nerve to shut down," Freeman said.

The study attributed this response to glial cells, the abundant but oftentimes overlooked supporting cell within the brain.

"Glial cells are the watch dogs of nervous system health," Freeman said. "Our work suggests that even when there's a relatively small injury to some neurons, they can run out like Paul Revere and shut everything down."

From an evolutionary perspective, Freeman theorizes that this bystander effect may help to conserve energy in large swaths of the nervous system following disease or injury. Bystander neurons then effectively revive once it becomes clear that they are uninjured.

"Our best guess is that it allows the nervous system to pause after an injury," he said. "It enables cells to assess their status and, if they're not healthy, activate programs to destroy themselves. If they're healthy, they recover."

Approximately 200,000 cancer patients are diagnosed with brain metastases each year, yet few treatment options exist because the mechanisms that allow cancer to spread to the brain remain unclear. However, a study recently published in the journal Cancer Cell by VCU Massey Cancer Center scientist Suyun Huang, M.D., Ph.D., offers hope for the development of future therapies by showing how a poorly understood gene known as YTHDF3 plays a significant role in the process.

Huang is renowned for her work in modeling the spread of cancer to the brain. Her most recent findings show that increased YTHDF3 expression correlates with brain cancer metastases and poor survival outcomes in breast cancer patients. They also demonstrated that the gene is required for multiple steps in the brain metastatic process.

"This study could provide a marker to help doctors diagnose brain metastases early, as well as provide a target for the development of new drugs to prevent and treat brain metastases," says Huang, a member of the Cancer Biology research program at Massey and professor in the Department of Human and Molecular Genetics at VCU School of Medicine.

Huang's team discovered that breast cancer brain metastases have increased YTHDF3 gene copy numbers in comparison to primary breast tumors. A gene's copy number refers to the number of times it appears in the genome. Additional copies of YTHDF3 in metastatic tumor DNA show that mutations have occurred as the cancer cells replicated and spread.

Using a variety of techniques, the researchers profiled the gene to develop a comprehensive view of how it facilitates key processes for brain cancer metastasis through its role in the production of various proteins that interact with the brain microenvironment. Through these experiments, they found that YTHDF3 contributed to the expression of a number of genes known to drive cancer development, including ST6GALNAC5, GJA1, EGFR and VEGFA. Mouse models lacking the YTHDF3 gene demonstrated prolonged survival and resistance to brain metastasis development.

"Now that we've shown how critical this gene is to the development of brain metastases, we plan to work on synthesizing drugs that can inhibit its function," says Huang. "This is an urgent need, and we're hopeful this research will eventually help save lives."

Researchers from the DSI/NRF Center for Invasion Biology at Stellenbosch University in South Africa have found that, scarcely a hundred years after Guttural Toads were introduced to the islands of Mauritius and Réunion, their overall body size has been reduced by up to a third compared to their counterparts in South Africa.

The Guttural Toad, a large amphibian species native to Africa, was introduced to Mauritius in 1922 and from there to Réunion in 1927 for biocontrol of cane beetles and malaria-carrying mosquitoes. While studying the history of this introduction, the researchers were amazed by how much smaller the island-based toads had become.

"Dwarfism in amphibians is known to have occurred in many lineages over millions of years, yet this study has identified it occurring in less than a hundred years, which raises questions about the evolutionary mechanisms driving this change," says Dr James Baxter-Gilbert, lead author of the article "Shrinking before our isles: The rapid expression of insular dwarfism in two invasive populations of guttural toad (Sclerophrys gutturalis)", published in the journal Biology Letters recently.

Another important finding is the significant reduction in the length of these amphibians' hindlimbs. According to the researchers, this could be because of changes to their reproductive strategy, or the absence of the toad's native predators. Alternatively, it could also be associated with the fact that once they spread across the islands the need for dispersal is no longer an important driver - similar to trends seen in island birds when they lose their ability to fly.

While biologists are familiar with this type of change occurring when colonising animal populations adapt to island-life, part of a phenomena known as the Island Syndrome, large-scale changes in body size, such as dwarfism or gigantism, have been associated with long evolutionary processes taking place over thousands or millions of years.

Dr Baxter-Gilbert explains: "The Island Rule puts forward the idea that, over time, large-bodied mainland species will dwarf in size as they adapt to island life. We know this from fossil and historic records, such as the miniature hippopotamuses (Hippopotamus creutzburgi) and elephants (Mammathus creticus) from Crete during the Pleistocene; while small-bodied mainland species will grow to become gigantic, such as the oversized and fearless Dodos (Raphus cucllatus) of Mauritius."

He says the research is a fascinating first step in understanding how biological invasions can radically change the biology of this island amphibian invader. "We are now planning to examine the mechanisms driving these changes. It appears that there is still much to learn," he said.

Marine scientists have mapped previously unknown foraging grounds and migratory routes of Western Australia's green turtles to support conservation of the iconic threatened species.

The Australian Institute of Marine Science-led study also examined where turtles spent time during the nesting season which will allow researchers to identify the area's most important to them and to determine where this overlaps with industrial activity.

The project saw researchers tag 20 female green turtles nesting at WA beaches and track them with satellites.

They then combined their data with that from a further 76 turtles tagged in previous studies.

AIMS marine ecologist Dr Luciana Ferreira said the ultimate goal in mapping the green turtle distribution was to provide the knowledge to help reduce the species' potential interactions with human activities in the resource rich areas of Australia's north-west.

"Existing spatial protections underestimate the foraging distribution of green turtles and are missing some important areas. It's really essential for the turtles' protection if we know where they go and what they do," Dr Ferreira said.

The study shows while green turtles use existing protected areas during the nesting season, they then migrate to previously unmapped foraging grounds where they spend most of their time.

This information on the turtles' movement patterns will help scientists, industry and environmental managers protect the species in areas that are important to Australia's economic development.

Most turtles foraged within Australian coastal waters, with only two per cent of the tagged green turtles crossing international boundaries.

"We had one turtle that swam to foraging areas in Indonesia," she said. "And two turtles tagged in WA travelled all the way to the Torres Strait.

"One turtle in the study travelled more than 3000 kilometres from her nesting area.

"Interestingly, 14 per cent remained in their nesting areas--instead of migrating away they just stayed there."

Despite the differences in where the turtles migrated to at the end of the nesting season, the team found two common migratory corridors for green turtles, one in the Pilbara and one in the Kimberley.

AIMS ecologist Dr Michele Thums said collaboration was crucial to the success of the project.

"Satellite tracking is expensive and tracking only a few turtles would not have provided an accurate distribution map," she said.

"Instead, working with industry and turtle scientists in WA we were able to compile data from almost 100 tracked turtles for our analysis."

The research drew on studies from the WA Department of Biodiversity, Conservation and Attractions, INPEX, Woodside Energy and Pendoley Environmental.

DBCA research scientist Dr Sabrina Fossette said turtles hold cultural, spiritual and economic importance for Indigenous Australians and the results are also of enormous interest to them.

"Turtles feature in many stories, ceremonies, traditions and contemporary activities of Indigenous people," she said.

Dr Fossette said the research will help inform the management of green turtles, which are listed as endangered by the International Union of Conservation of Nature (IUCN).

"We have a good idea of where green turtles nest in Western Australia but until now we didn't know a lot about where they go when they leave those areas," she said.

Aurora, Colo. (Dec. 7, 2020) -- Children's Hospital Colorado (Children's Colorado) Center for Cancer and Blood Disorders (CCBD) announced today that a study about the manipulation of bone marrow stem cells into innate lymphoid and natural killer cells will be published in Science Immunology, a well-respected, high-impact medical journal.

It is well established that bone marrow stem cells give rise to all types of blood cells. However, the conditions that drive this process are not understood. The Children's Colorado research conducted on the Anschutz Medical Campus characterizes how the cancer fighting Natural Killer (NK) cells develop. The work also shows how another blood cell type, called "innate lymphoid cells" develop. This latter cell type is involved in many aspects of human health and disease.

By understanding these factors, researchers will be able to manipulate the stem cells and tailor therapies for children and adults who are receiving cancer treatments in the years to come. Based on the results of the Children's Colorado CCBD study, the team applied for intellectual property protection around the methods used in the research, and the paper was accepted by Science Immunology.

"We are very encouraged by the results of this study and believe the results will help us better treat children and adults in the future," said Mike Verneris, MD, professor, Pediatrics-Hematology/Oncology and Bone Marrow Transplantation. "This significant research and subsequent publication in Science Immunology distinguishes Children's Colorado as a leader in the medical community and sets us up for meaningful advances in cancer treatment and therapies in the future."

As the holder of the Barton Family Endowed Chair in Bone Marrow Transplant, Dr. Verneris has relied on philanthropic support to advance his groundbreaking research. In addition to federal research funding, the investment of generous donors played a critical role in this breakthrough.

Scientists at St. Jude Children's Research Hospital recently identified genetic variants in childhood cancer survivors of African ancestry that increase their risk of treatment-related heart problems. The findings, which have implications for how the health of these survivors is monitored, were published online today in Cancer Research, a journal of the American Association for Cancer Research.

"Childhood cancer survivors are a unique population," said corresponding author Yadav Sapkota, Ph.D., of the St. Jude Department of Epidemiology and Cancer Control. "But within that group, survivors of African ancestry are an even more specific population, who until now have generally been excluded from studies looking into the genetic mechanisms behind health outcomes among pediatric cancer survivors."

Cardiomyopathy occurs at significantly higher rates in survivors of childhood cancer than the general population. However, research into the effect of genetic variants on patients' health among racial and ethnic groups is lacking, often because of the rarity of patient data. Researchers at St. Jude used the St. Jude Lifetime Cohort study, a large cohort of childhood cancer survivors followed over time, to study risk of cardiomyopathy in childhood cancer survivors of African ancestry.

The findings showed that when compared to survivors of European ancestry, childhood cancer survivors of African ancestry are 2.5 times more likely to develop cardiomyopathy. The results accounted for known cardiovascular risk factors such as hypertension, diabetes, dyslipidemia, physical activity, alcohol consumption and smoking.

After establishing that African American childhood cancer survivors are at a higher risk of developing cardiomyopathy, the researchers looked for biologic mechanisms that could account for the difference. The scientists identified two distinct genetic variants associated with cardiomyopathy in African American survivors.

"As a group, childhood cancer survivors represent a highly heterogenous population with respect to type of cancer and treatment exposures. Thus, it is often important to investigate treatment-related risks within well-defined subgroups," said author Leslie Robison, Ph.D., chair of the St. Jude Department of Epidemiology and Cancer Control. "The genetic variants identified in this study demonstrate the importance of considering associations within racial or ethnic subgroups."

On chromosome 15q25.3, the variant (rs9788776) occurs only in survivors of African descent and increases cardiomyopathy risk by 4.5 times. On chromosome 1p13.2, the variant (rs6689879) increases cardiomyopathy risk in survivors of African descent by 5 times. The rs6689879 variant does occur in survivors of European descent, but only increases their cardiomyopathy risk by 1.3 times. Additional findings suggested a mechanism by which the 1p13.2 variant leads to cardiomyopathy by up-regulation of the gene PHTF1, a transcription factor.

This study has implications for long-term follow-up and surveillance of childhood cancer survivors of African ancestry.

"All childhood cancer survivors should be monitored for cardiac late effects, but as we gain a more granular understanding of cardiomyopathy risk among different populations, we can start to focus interventions on those individuals with the greatest need," said author Melissa Hudson, M.D., St. Jude Cancer Survivorship Division director.

Despite decades of investigation, Tibet's ancient topography and its role in climatic and biotic evolution remain speculative due to a paucity of quantitative surface height measurements through time and space, and sparse fossil records.

During the Second Tibetan Plateau Scientific Expedition in Tibet, an international research team from the Xishuangbanna Tropical Botanical Garden (XTBG) and the Institute of Vertebrate Paleontology and Paleoanthropology discovered a highly diverse fossil assemblage from the current elevation of 4,850 m in the Bangor Basin in central Tibet.

"These fossils characterize a luxuriant seasonally wet and warm Shangri-La forest that once occupied a deep central Tibetan valley along the Banggong-Nujiang Suture (BNS)," said Dr. SU Tao, who published this research in PNAS.

The 70 plant fossil taxa so far recovered include the first occurrences of several modern Asian lineages and represent a middle Eocene (about 47 million years ago) humid subtropical ecosystem.

Many taxa in the Jianglang flora, e.g., Apocynaceae, Ceratophyllum, Illigera, Lagokarpos, and Vitaceae, represent first discoveries for the plateau, and some are the oldest fossil records for these taxa in Asia, e.g., Apocynaceae, Cedrelospermum, Lagokarpos, and Limnobiophyllum.

"These fossils not only record the diverse composition of the ancient Tibetan biota, but also allow us to constrain the middle Eocene land surface height in central Tibet to 1,500 ± 900 m, and quantify the prevailing thermal and hydrological regime," said Prof. ZHOU Zhekun of XTBG.

By reconstructing ancient climate parameters encoded in leaf morphological traits, the researchers quantified both the climate and elevation of central Tibet in the middle Eocene. They calculated that the forest grew at an elevation of about 1500 meters within an east-west trending valley under a monsoonal climate.

"In the future, the complex topography of Tibet in the geological past needs to be considered when studying the paleoenvironmental and biodiversity histories on the plateau," said Dr. SU Tao.

Rural central Namibia is one of the most important strongholds of the declining global cheetah population. Here, the rarest large African cat lives on privately owned farmland. A traditional conflict poses a threat to them, as they occasionally prey on cattle calves and are therefore rarely welcomed on the farms. New insights into the cheetah's spatial behaviour provide a viable solution to this human-wildlife conflict: In the core areas of male cheetah territories all local males and females frequently meet to exchange information. This results in hotspots of cheetah activity in these "communication hubs" and in substantially less activity in the vast areas between the core areas of the territories. Implementing this knowledge and moving their breeding herds with young calves out of these hotspots, farmers were able to reduce livestock losses by more than 80 percent. These insights are the result of a close and trusting cooperation between scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and farmers in central Namibia. They are published in the scientific journal Proceedings of the National Academy of Sciences of the United States of America.

The cheetah (Acinonyx jubatus) is the rarest big cat species in Africa and its numbers have substantially decreased over the last decades to now less than 7,000 adult individuals. In central Namibia, one of the most important strongholds of the species, the cheetahs live on privately owned farmland, not inside protected areas. This has caused conflict with cattle farmers on whose calves the cheetahs occasionally prey. In the past, they have been removed repeatedly by farmers. "This conflict is an important reason for the decline of the Namibian cheetah population, thus solutions to this conflict that are viable for both farmers and cheetahs needed to be developed," says Dr Jörg Melzheimer, spatial ecologist of the Leibniz-IZW Cheetah Research Project (CRP) in Namibia, which is primarily funded by the Messerli Foundation from Switzerland. To find such solutions, the CRP started a research programme on the spatial ecology of cheetahs in 2002 and established a trusting collaboration with many farmers in Namibia. "Supported by the farmers we caught more than 250 cheetahs and equipped many of them with high resolution GPS collars to thoroughly analyse their spatial behaviour," adds Dr Bettina Wachter, head of the CRP. The collars recorded an average of 96 GPS coordinates per day per cheetah, or several million individual locations across all individuals.

With the help of this enormous dataset, the Leibniz-IZW scientists identified two distinct spatial tactics of male cheetahs. Approximately one third of all males own small territories which they scent-mark at 20 to 40 prominent landmarks such as trees, rocks or termite mounts in the core area. Other males, called floaters, do not own a territory but roam over vast areas. "The territories are not contiguous, but spread evenly across the landscape with a lot of open space between them," Melzheimer explains. "Floaters visit the core areas of the territories frequently to gather information on the current territory holders and to consider their chances of queueing for territory ownership or winning a fight for the territory. At the same time, the females regularly visit these areas in search of mating partners." As a consequence, the core areas of the territories function as communication hubs for the local cheetah population and are effectively hotspots of cheetah activity.

These communication hubs are typically 25 square kilometres in size, situated 20 to 25 kilometres apart and thus make up only 10 percent of the total area. They represent areas with a high local predation risk for livestock, whereas the remaining lands between communication hubs make up 90 percent of the total area and entail only a low predation risk. Although the communication hubs cover only a small part of the study area, mapping of all hotspots revealed that about 30 percent of the cattle farmers are affected to varying degrees by cheetah activity.

Based on these findings the Leibniz-IZW scientists designed an experiment together with the farmers. Where the farmers unwittingly kept breeding herds with young calves within the communication hubs, the scientists suggested to move them to areas with much less cheetah activity. "These experiments were highly successful and reduced the livestock losses of farmers by more than 80 percent," Melzheimer and Wachter sum up. "We demonstrated that cheetahs did not follow the breeding herds, but maintained their spatial system of communication hubs and instead preyed on wildlife occurring naturally on the farms in the hotspot locations. This implies that there are no problem cheetahs, but problem areas with high predation risk".

The key to the new scientific results and their application to the farmer-cheetah conflict was a long-term collaboration of the scientists with the cattle farmers in central Namibia. This collaboration was based on the concept of a "real-world laboratory" where scientists and farmers formulate research questions and goals together, co-develop a research design, collaborate on capturing and collaring cheetahs and collecting data on livestock losses, and thereby co-create knowledge and potential solutions to the conflict. "This allowed us to work as partners on a real-world problem and to find solutions together, as well as to communicate them in the relevant communities, thereby helping to spread the successful application of the solutions", Melzheimer explains. "The future of the cheetah does not lie in the hand of scientists or conservationists, it depends on all stakeholders working together on viable solutions".

In the past 20 years, Central Europe has experienced six summer heat waves and droughts. Until now, however, it was unclear what factors led to these extreme events. Researchers from two Helmholtz Centres (AWI & UFZ) have now discovered that in Central Europe, temperature and precipitation patterns in April play a vital role in determining whether or not the soils are drier than average in the following summer. If the April is too warm, with little precipitation, a large proportion of the moisture stored in the soil evaporates, making a summer drought more likely. The team has also identified one of the reasons for the repeated dry Aprils and the correspondingly increased risk of drought. Decreasing temperature differences between the Arctic and the middle latitudes lead to a shift in the jet stream and the formation of a blocking high-pressure system over the North Sea and parts of Germany. This in turn means that the April weather in Central Europe is getting much too warm and dry, as the researchers report in a study released today in the Nature Partner Journals npj Climate and Atmospheric Science.

Monica Ionita, a climatologist and expert on weather forecasting at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), can still remember it clearly: in late April 2018, it was so hot in Bremen that she put a paddling pool in the garden for her daughter, although it should have been much too early to splash around outdoors. She now knows that the spring heat wave at the time provided the impetus for the following summer being one of the driest in the history of Central Europe.

"Since the turn of the century, Central Europe has experienced repeated summer heat waves and droughts, which have caused damage amounting to millions of Euros. To date, attempts to correctly predict such extreme events have been unsuccessful because the influence of the spring has been underestimated. That is why we decided to closely investigate the links between the weather in spring and that in the subsequent summer - for the entire period for which sufficient records are available. In other words, the last 140 years," the expert reports.

April's pivotal role: Lack of rain coupled with heat causes soils to dry out

For the analysis, Monica Ionita and her colleagues employed climate (and hydrologic) model outputs as well as statistical methods that the AWI researchers have developed; and had already successfully applied in long-term forecasts of river water levels. The findings show: in the last 14 years, the temperature and precipitation trends in April have changed fundamentally. "While there was little change in the months of March and May in the period 2007 to 2020, April was on average 3 degrees Celsius warmer compared to the reference period 1961 to 2000. In extreme years, like 2018, it was so warm in April that the snow that had fallen in winter virtually evaporated before it had the chance to drain into the soil in the form of meltwater. Furthermore, since 2007, in most regions of Central Europe there has only been half as much rain as in the reference period," Ionita explains.

In the past 14 years, the absence of precipitation has only been one of the problems: "Rising April temperatures have led to the moisture stored in the soil evaporating. As a result, in spring there was already a marked lack of moisture in the soils of Central Europe, especially in Germany. As a rule, this deficit couldn't be compensated for in the summer. In other words: the summer drought in the soils was pre-programmed back in April," adds Rohini Kumar, a hydrologist at the Helmholtz Centre for Environmental Research (UFZ) in Leipzig and co-author of the new study.

The causes of dry springs in Central Europe

But which weather conditions over Central Europe cause the repeated record-high temperatures and dry spells in April? "Our analysis shows that a blocking high-pressure system formed over the North Sea and parts of Germany in that period, and this diverted the jet stream northwards, resulting in spells of sunny and dry weather in Central Europe lasting up to two weeks," explains Ionita. There was also a phase with similarly low precipitation in April in the period from 1881 to 1895. But at the time it wasn't as warm, which meant that less moisture evaporated from the soil and there weren't the long-term effects that we're seeing today. "The serious consequences of these spring dry spells are largely due to the rising air temperatures," comments Ionita.

We can't yet say whether blocking high-pressure systems will determine the April weather in Central Europe in the future, since the climate is subject to natural fluctuations. But in their study, the scientists were able to identify one important driver: "One reason for the formation of stable high-pressure areas is the decreasing temperature differences between the Arctic and the middle latitudes in spring. Under these conditions, the jet stream that controls the weather in Central Europe follows a zigzagging course, allowing the high-pressure system to settle over the North Sea," Ionita adds.

According to climate scenarios, these initial conditions will also occur in the future. However, high-pressure systems will form less frequently (be less likely to form) if we succeed in achieving the Paris climate goals and limit global warming to 1.5 degrees Celsius by 2100. "If temperature increases exceed this goal, it is highly likely that such high-pressure areas will form. In Central Europe, the month of April will continue to be warmer and drier than it was 20-30 years ago, thus paving the way for large-scale water shortages and arid soils all summer long," warns the AWI researcher.

"Such a development would have major effects on the soils' water balance and their associated ecosystem services," states Kumar, adding: "In recent years, we've seen a series of summer droughts throughout Central Europe - with severe consequences in terms of plant productivity and low water-levels in rivers. Understanding the conditions under which such dry periods occur is vital to implement precautionary and preventive measures in time."