Earth

Small photosynthetic marine algae are a key component of the Arctic marine ecosystem but their role for the ecology of the Arctic Ocean have been underestimated for decades. That's the conclusion of a team of scientists who synthesized more than half a century of research about the occurrence, magnitude and composition of phytoplankton blooms under Arctic sea ice. The results were published in a special issue of Frontiers in Marine Science devoted to Arctic Ocean research.

Phytoplankton are free-floating microscopic organisms, most of which are single-celled algae. Like terrestrial plants, they use photosynthesis to turn light into chemical energy by consuming carbon dioxide (CO2) and nutrients in the water. Phytoplankton are the basis of the marine food web and play a vital role in the carbon cycle by absorbing CO2 from the atmosphere.

Until roughly a decade ago, most scientists assumed that phytoplankton remained in a sort of stasis throughout the winter and spring until sea ice break-up. Now there is a growing body of evidence that suggests under-ice blooms (UIBs) of phytoplankton, like a sudden spring flowering in a garden, can occur in low-light environments below sea ice.

"There was a long-standing assumption that what was happening under the sea ice in the water column was almost 'on pause' during the polar night and before seasonal sea ice retreat, which is apparently not the case," said lead author Dr Mathieu Ardyna, a postdoctoral Marie Sklodowska-Curie fellow at Stanford University.

The revelation means that phytoplankton production in some regions of the Arctic Ocean may be an order of magnitude greater than originally predicted. That's important for climate modelers who want to know how much atmospheric carbon is being absorbed by these algae.

Few places on Earth are transforming as rapidly as the Arctic due to climate change. Over the past 30 years, the Arctic has warmed at roughly twice the rate as the global average. One of the most visible signs of that change has been in the decline of the sea ice that floats on the ocean surface, with this year's ice cover shrinking to the second lowest extent on record.

It's no surprise that the thinning ice cover has enabled phytoplankton, which require light for photosynthesis, to flourish. What was surprising to Ardyna and his colleagues is that the phenomenon of UIBs occurred well before climate change affected Arctic sea ice.

"Digging up research that occurred from the '50s and prior demonstrates that blooms, albeit not very large, were occurring under thick ice in the central Arctic," he explained. "I think this fact surprised many of us, as models had suggested this was not the case."

The historical observations included a pair of studies during the International Geophysical Year, a global campaign that ushered in the modern scientific era. The authors noted, "The end result of this work was nothing less than an incredible first glimpse of UIBs occurring in the central Arctic."

The paper goes on to describe the variability among UIB events across the Arctic Ocean in terms of occurrence, magnitude, and even the type of organisms present. Some of those findings are based on scientific programs and expeditions dedicated to studying UIBs specifically. In many cases, observations relied on autonomous floats, robotic gliders and even remotely operated vehicles that can swim under the sea ice.

Ardyna said further observations to feed new computer models will be key to more accurately predict how the Arctic carbon cycle will change in the future.

"So many questions remain unanswered about this critical period of spring, for many Arctic species, for their food or their life cycle," he said. "Given the remoteness of the Arctic, one way will definitely be to develop more and better autonomous platforms to give us valuable information."

Cardiovascular disease is the leading cause of mortality and ischemic heart disease is a major cause of death worldwide. Coronary vessels that nourish the heart develop from three main sources, the endocardium on the inner surface of the hearts blood-filled chambers being one of the major contributors. In normal conditions, the adult heart can no longer generate new blood vessels from the endocardium, because the endocardium-to-coronary vessel transition is blocked by a connective tissue wall beneath the endocardium. In the study published this week, an international team led by researchers of the Wihuri Research Institute and the University of Helsinki show that the VEGF-B growth factor can be used to activate the growth of vessels inside of the heart during cardiac ischemic damage.

This novel finding opens the possibility, that vessels emerging from the inner side of the heart could be further developed for the treatment of myocardial infarction, which results from insufficient delivery of oxygen to cardiac tissue. In normal conditions, blood nourishes the adult heart through coronary vessels. The largest coronary vessels are located on the heart surface, and their branches dive into heart muscle to deliver oxygen-rich blood into the inner parts of the heart. Occlusion of the largest coronary arteries due to atherosclerosis and blood clotting is commonly treated by catheter-mediated reopening. However, any remaining blood clots in the small coronary vessels inside the heart cannot be removed, which can lead to local infarction of the heart muscle. Due to the long distance of blood delivery to the inner myocardium, and pressure conditions during heartbeat, infarctions of the inner myocardium are particularly common in patients with hypertension.

Increasing coronary vessels by using VEGF-B

VEGF-B (vascular endothelial growth factor) belongs to a family of growth factors that regulate the formation of blood- and lymphatic vessels. Professor Ulf Eriksson at the Karolinska Institute together with academy professor Kari Alitalo were the first to isolate the VEGF-B gene in 1996. Together with the research group of professor Seppo Ylä-Herttuala, they previously showed that VEGF-B can induce the growth of coronary vasculature.

Earlier attempts to utilize another growth factor gene, VEGF-A, to grow new vessels in the heart have failed, mostly due to the leakiness of the vessels and increased inflammation caused by VEGF-A, but not by VEGF-B.

"The highlight of this study is that by using VEGF-B, we were able to induce the growth of new vessels from the inner surface of the cardiac ventricles during heart development, and again in adult mice, in the ischemic inner parts of the heart", says Markus Räsänen MD, PhD.

"Such kind of a novel "bypass route" could open translational therapeutic possibilities for the treatment of coronary artery disease. Re-activation of the embryonic vessel growth program in adult endocardium could be a new therapeutic strategy for cardiac neovascularization after myocardial infarction. For possible future clinical use, the function of these vessels and their blood flow has to be further studied to ensure that they really increase transport of oxygen and nutrients into the cardiac muscle", confirms the director of Wihuri Research Institute, academy professor Kari Alitalo.

Natural materials like skin, cartilage and tendons are tough enough to support our bodyweight and movements, yet flexible enough that they don't crack easily. Although we take these properties for granted, replicating this unique combination in synthetic materials is much harder than it sounds. Now, scientists at EPFL have developed a new way of making strong, supple composite polymers that more closely mimic materials found in the natural world. Their breakthrough, described in a paper appearing in Advanced Functional Materials, could have applications in fields such as soft robotics and cartilage prosthetic implants.

Normally, synthetic hydrogels fall into two very different material categories. The first type, which includes window glass and some polymers, are hard and load-bearing but notoriously poor at absorbing energy: even the slightest crack can spread through the structure. Materials in the second group are better able to resist cracking, but there's a trade-off: they're extremely soft - so soft, in fact, that they can't bear heavy loads. Yet some natural composites - made from a combination of biological materials and proteins, including collagen - are both strong and crack-resistant. They owe these properties to their highly precise structure, from the nano to the millimeter scales: for example, woven fibers are organized into larger structures, which in turn arrange to form other structures, and so on.

"We're still a long way from being able to control the structure of synthetic materials at so many different scales," says Esther Amstad, an assistant professor at EPFL's Soft Materials Laboratory and the paper's lead author. Yet Matteo Hirsch and Alvaro Charlet - two doctoral assistants working under Amstad's guidance - have devised a new approach to building synthetic composites, taking their cues from the natural world. "In nature, basic building blocks are encapsulated in compartments, which are then released in a highly localized way," explains Amstad. "This process provides greater control over a material's final structure and local composition. We took a similar approach, arranging our own building blocks into compartments then assembling them into a superstructure."

First, the scientists encapsulated monomers in droplets of a water-and-oil emulsion, which serve as the compartments. Inside the droplets, the monomers bind together to form a network of polymers. At this point, the microparticles are stable but the interactions between them are weak, meaning the material doesn't hold together well. Next, the microparticles - which are highly porous like sponges - were soaked in another type of monomer before the material was reduced to form a kind of paste. Its appearance, as Alvaro Charlet puts it, is "a bit like wet sand that can be shaped into a sandcastle".

The scientists then 3D-printed the paste and exposed it to UV radiation. This caused the monomers added at the second step to polymerize. These new polymers intertwined with the ones formed earlier in the process, thereby hardening the paste. That resulted an exceptionally strong, hard-wearing material. The research team showed that a tube measuring just 3 mm across can withstand a tensile load of up to 10 kg and a compressive load of as much as 80 kg with no damage to its structural integrity.

Their discovery has potential uses in soft robotics, where materials that mimic the properties of living tissues are highly sought-after. The ground-breaking process could also be applied to develop biocompatible materials for cartilage prosthetic implants.

Research led by the Centenary Institute, the University of Technology Sydney and the University of Queensland has shown for the first time a link between chronic obstructive pulmonary disease (COPD), an often fatal lung condition, and the gut microbiome.

The findings, published in the high impact science journal 'Nature Communications', suggests that the gut may be helpful in diagnosing COPD and may also be a potential source of new therapeutic targets to help treat the chronic respiratory disorder.

"It's already known that the lung microbiome is a contributing factor in COPD," said Professor Phil Hansbro, senior author of the study and Director of the Centenary UTS Centre for Inflammation.

"We wanted to see if the gut environment was also somehow involved-to determine whether the gut could act as a reliable indicator of COPD or if it was connected in some way to the development of the disease."

In the study, the researchers compared the microbiome and metabolite profiles of stool samples from COPD patients with healthy individuals. Revealed were significant differences between the two groups.

COPD patients exhibited increased levels of the bacteria Streptococcus and Lachnospiraceae in their stool samples. Also identified in individuals with COPD was a unique metabolite signature-formed by the chemical by-products of the metabolic process.

"Our research indicates that the gut of COPD patients is notably different from healthy individuals," said first author on the paper Dr Kate Bowerman, University of Queensland.

"This suggests that stool sampling and analysis could be used to non-invasively diagnose and monitor for COPD," she said.

The study's researchers believe that the altered gut microbiome found in COPD patients could also support the gut as a potential target for new treatments.

"The 'gut-lung axis' describes the common immune system of the lung and gastrointestinal tract. This means that activity in the gut can impact activity in the lung. Our COPD findings suggest that the gut microbiome should now also be considered when looking for new therapeutic targets to help treat lung disease," said Professor Hansbro.

COPD, a life threatening inflammatory disorder of the lungs, is the third most common cause of death globally. More than 3 million lives are lost every year to COPD.

Stopping the replication of SARS-CoV-2 is likely possible thanks to a compound called EBSELEN: a group of researchers from the Politecnico di Milano has communicated aspects relevant to the blocking of replication mechanism in the New Journal of Chemistry.

Two important aspects of the propagation of a virus are its ability to enter the host's cells, that is, to infect the host, and then to replicate in infected cells.

As for SARS-CoV-2, the Mpro protein plays an important role in the replication and transcription of the virus. Mpro therefore represents a particularly promising target for blocking the virus itself because a compound that inhibits Mpro blocks the virus.

EBSELEN proved to be the most potent inhibitor of Mpro in a study examining approximately 10,000 selected compounds. In their study, the researchers at Politecnico elucidate key aspects of the Mpro blocking mechanism by EBSELEN.

"We have identified that the selenium atom of EBSELEN strongly interacts with some groups typically present in proteins via the chalcogen bond, a weak bonding that has been studied for years in our laboratories; this binding may contribute to the inhibition of the virus replication. This represents an important step forward in the fight against COVID-19. " Says Prof. Giuseppe Resnati of the Department of Chemistry, Materials and Chemical Engineering "Giulio Natta" of the Politecnico di Milano.

The article clarifies the details of the EBSELEN / enzyme binding mechanism. It is shown that selenium plays a fundamental role in establishing the interactions that favor the binding of EBSELEN to SARS-CoV-2 and to other pathogenic retroviruses in humans such as those of HIV and Hepatitis C.

When it comes to optimizing “longevity fitness” through attention to social, health, and wealth aspects of life, many Americans face intractable inequities based on the color of their skin, where they live, their sex, and who they love. The COVID-19 pandemic has further demonstrated the additional impacts affecting these demographics through the increased number of cases and mortality rates.

“The Impact of Diversity on Longevity Fitness: A Life-Course Perspective” — the third report in a series developed by The Gerontological Society of America and supported by Bank of America — documents the effects of these inequities and explores the beneficial efforts of corporations and other employers to enhance diversity and inclusion. It uses the term longevity fitness to describe how people can thrive, not just survive, throughout increasingly long life spans by achieving social, health, and wealth equity.

“Our nation’s diversity is one of its great strengths, but we have marginalized certain groups and made it difficult for them to accumulate financial, health, and social equity,” said Richard W. Johnson, PhD, of the Urban Institute, who chaired the workgroup that oversaw content development for the new publication. “This report shows how government and business can work together to help everyone thrive throughout their lives.”

The report calls for deep cultural shifts in the place, race, gender, and sexual orientation/identity aspects of life. It states that in order to promote longevity fitness, the inherent biases in the ways people look at one another and treat each other must be addressed.

“With this research, The Gerontological Society of America has taken an important step to understand how to navigate our journeys in life better in an era of longer life spans, with a particular emphasis on diversity in our society,” said Kai Walker, Inclusion Executive, Retirement and Personal Wealth Solutions, Bank of America. “As we all navigate this current pandemic, this report — together with our own research on life priorities and life stages — provides actionable and inclusive guidance to individuals and families throughout their financial lives.”

Over the past three years, The Gerontological Society of America and Bank of America have explored the increasingly long life spans enjoyed by Americans through economic, fitness, and diversity lenses. The 2018 report, “Longevity Economics: Leveraging the Advantages of an Aging Society,” addressed the problems of systemic ageism and age discrimination and the need for policies and programs that recognize the reality of people living far past the historical retirement age of 65. In 2019, “Longevity Fitness: Financial and Health Dimensions Across the Life Course” detailed how people can thrive, not just survive, throughout longer lifespans by making changes in their lives aimed at maximizing social, health, and wealth equity.

A mutation in the CLCN6 gene is associated with a novel, particularly severe neurodegenerative disorder. Scientists from the Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and the Max Delbrück Center für Molekulare Medizin (MDC), together with an international team of researchers, have now analyzed the effect of a point mutation that was found in three unrelated affected children. ClC-6 is one of nine members of the CLCN gene family of chloride channels and chloride/proton exchangers and, apart from ClC-3, was the only one that could not yet be associated with any human disease. The results have just been published in the American Journal of Human Genetics.

The term "lysosomal storage disease" summarizes a number of genetically determined metabolic diseases that are due to incorrect or insufficient function of lysosomes. These cellular organelles are important both as "cellular waste disposal" and for the regulation of cellular metabolism. If lysosomal function is compromised, substances that normally would be degraded may accumulate in the affected cells. This may impair their function and may eventually lead to cell death. In the central nervous system, which is often affected because adult neurons are unable to regenerate, this can lead to neurodegeneration.

Researchers from the Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and the Max-Delbrück-Centrum für Molekulare Medizin (MDC), in close collaboration with colleagues from Rome, Hamburg and the USA, have now found and characterized the gene defect underlying a novel severe form of neurodegenerative disease: A mutation in the CLCN6 gene in three unrelated children from Italy, Germany and the USA, leads to severe developmental delay, intellectual disability, hypotonia severely affecting muscle tone, respiratory insufficiency, visual impairment, and early-onset brain atrophy.

Ion transporter ClC-6 is a member of the chloride channel family

Human geneticists, including the study's co-leader Marco Tartaglia from Rome and Kerstin Kutsche from Hamburg, independently discovered the same point mutation in their young patients and asked Prof. Thomas Jentsch and his team to examine possible effects of the mutation on the transport properties of ClC-6 and its cellular functions. Jentsch, the discoverer of the CLC chloride channel family, had already found or characterized different disease-causing mutations in almost all nine CLC genes. These are associated with a broad spectrum of different pathologies. Only the genes encoding the ion transporters ClC-3 and ClC-6 had not yet been found to be mutated in human disease. "About fifteen years ago, we had generated a ClC-6 knockout mouse and found that it displayed mild neuronal lysosomal storage. However, our search for patients with similar loss function mutations in ClC-6 was unsuccessful," explains Prof. Jentsch. "Now we have identified a different type of ClC-6 mutation in a much more severe human disease."

The presence of exactly the same mutation in three independent patients displaying the same disease pattern already indicated a causal role of the mutation. But only the functional analysis in cell culture brought final certainty and led to the classification as lysosomal disease. "Our cell cultures experiments clearly show that increased ion transport by the mutated ClC-6 affects lysosomes and thereby prove the deleterious effect of the mutation. Based on these results, and taking into account our previous mouse model, we assume that the novel disease can be classified as lysosomal storage disease," explains Thomas Jentsch. However, definitive proof of this classification would require post-mortem examination of brain slices from patients or a novel mouse model carrying the same mutation.

More chloride uptake leads to abnormally large, lysosome-like vesicles

Unlike the chloride channels ClC-1, -2, -3 and -K, the chloride/proton exchangers ClC-3, -4, -5, -6, and -7 are not located on the plasma membrane but in intracellular membranes, mainly on endosomes and lysosomes. In previous studies, Jentsch and coworkers identified mutations of ClC-7 as the cause of a form of lysosomal storage disease associated with osteopetrosis, and mutations of ClC-4 lead to intellectual deficits. While ClC-7 is found on lysosomes, ClC-6 is predominantly located on late endosomes, kind of lysosome precursors.

The Berlin team found that the patients' mutation, in contrast to the loss of ClC-6 in their previous knock-out mouse model, caused a hyperactive ClC-6: The transport of chloride and protons was highly increased and was no longer modulated by pH. Normally acidic pH, as gradually achieved in the transition from endosomes to lysosomes, inhibits the transporter. This regulation is missing in the disease-causing mutant. The increased, unregulated ion transport - a pathological gain of function - resulted in drastically enlarged, lysosome-like vesicles in cells that were made to produce the mutated ClC-6. According to Jentsch, this pathological gain of function can explain the children's disease. "Vesicles carrying the mutated ClC-6 in their membrane are pathologically enlarged by an increased uptake of chloride, which is later followed by water. This uptake is driven by the ClC-6-mediated exchange for protons which are abundantly present in the acidic interior of vesicles. This severely impairs the function of lysosomes and, in the long run, probably leads to lysosomal storage in neurons, cells that are unable to proliferate. The tissue distribution of ClC-6, which is found almost exclusively in neurons, contributes to the predominantly neurological disease ".

"The present work highlights the importance of ion transport for the endosomal-lysosomal pathway," says Jentsch. "We see a broad spectrum of genetic diseases that are caused by mutations in vesicular CLCs or in different intracellular channels." Very different organs can be affected: For example, mutations in the endosomal ClC-5 lead to kidney stones and protein loss into the urine, as Jentsch's team showed a long time ago.

Jentsch is confident that also the ClC-3 exchanger will soon be linked to a genetic disease - a KO mouse previously published by the group shows dramatic neurodegeneration. Together with the current finding, this would link all nine CLCN genes to human genetic disease. "The gap is closing", says Jentsch, "and we can see very clearly how important basic research - we had cloned the first CLC from an electric fish - is for the diagnosis and understanding of human disease".

Mangoes, like other orange fruits and vegetables, are rich in beta-carotene and provide antioxidants that may delay cell damage. A new study from researchers at the University of California, Davis, finds eating Ataulfo mangoes, also known as honey or Champagne mangoes, may have another benefit -- reducing facial wrinkles in older women with fairer skin. The study was published in the journal Nutrients.

Postmenopausal women who ate a half cup of Ataulfo mangoes four times a week saw a 23 percent decrease in deep wrinkles after two months and a 20 percent decrease after four months.

"That's a significant improvement in wrinkles," said lead author Vivien Fam, a doctoral student in the UC Davis Department of Nutrition. But the findings are very specific and come with a caveat.

"Women who ate a cup and a half of mangoes for the same periods of time saw an increase in wrinkles. This shows that while some mango may be good for skin health, too much of it may not be," Fam said.

Researchers said it's unclear why consuming more mango would increase the severity of wrinkles but speculate that it may be related to a robust amount of sugar in the larger portion of mangoes.

QUANTIFIABLE RESULTS

The randomized clinical pilot study involved 28 postmenopausal women with Fitzpatrick skin types II or III (skin that burns more easily than tans). Women were divided into two groups: one group consumed a half cup of mangoes four times a week for four months, and another consumed a cup and a half for the same period of time. Facial wrinkles were evaluated using a high-resolution camera system.

"The system we used to analyze wrinkles allowed us to not just visualize wrinkles, but to quantify and measure wrinkles," said Robert Hackman, professor in the Department of Nutrition and corresponding author of the study. "This is extremely accurate and allowed us to capture more than just the appearance of wrinkles or what the eye might see."

The study looked at the severity, length and width of fine, deep and emerging wrinkles. Fam said the group that consumed a half cup of mangoes saw improvements in all categories.

Fam said further research is needed to learn the mechanisms behind the reduction in wrinkles. She said it may be due to the beneficial effects of carotenoids (orange or red plant pigments), and other phytonutrients that could help build collagen.

Materials scientists at Duke University have devised a simplified method for calculating the attractive forces that cause nanoparticles to self-assemble into larger structures.

With this new model, accompanied by a graphical user interface that demonstrates its power, researchers will be able to make previously impossible predictions about how nanoparticles with a wide variety of shapes will interact with one another. The new method offers opportunities for rationally designing such particles for a wide range of applications from harnessing solar energy to driving catalytic reactions.

The results appear online on November 12 in the journal Nanoscale Horizons.

"Faceted nanoparticles can lead to novel assembly behaviors, which haven't been explored in the past," said Brian Hyun-jong Lee, a mechanical engineering and materials science graduate student at Duke and first author of the paper. "Cubes, prisms, rods and so on all exhibit distinct distance- and orientation-dependent interparticle interactions that can be utilized to create unique particle assemblies that one cannot obtain through self-assembly of spherical particles."

"Every time I go through the latest set of published papers in nanotechnology, I see some new application of these types of nanoparticles," added Gaurav Arya, associate professor of mechanical engineering and materials science at Duke. "But accurately calculating the forces that pull these particles together at very close range is extremely computationally expensive. We have now demonstrated an approach that speeds those calculations up by millions of times while only losing a small amount of accuracy."

The forces at work between nanoparticles are called van der Waals forces. These forces arise because of small, temporary shifts in the density of electrons orbiting atoms according to the complex laws of quantum physics. While these forces are weaker than other intermolecular interactions such as coulombic forces and hydrogen bonds, they are ubiquitous and act between each and every atom, often dominating the net interaction between particles.

To properly account for such forces between particles, one must calculate the van der Waals force that every atom in the particle exerts on every atom in a nearby particle. Even if both of the particles in question were miniscule cubes of sizes smaller than 10 nanometers , the number of calculations summing all such interatomic interactions would be in the tens of millions.

It's easy to see why trying to do this over and over for thousands of particles located at different positions and in different orientations in a multiparticle simulation quickly becomes impossible.

"Lots of work has been done to formulate a summation that gets close to an analytical solution," said Arya. "Some approaches treat particles as made up of infinitesimally small cubes stuck together. Others try to fill space with infinitesimally thin circular rings. While these volume-discretization strategies have allowed researchers to obtain analytical solutions for interactions between simple particle geometries like parallel flat surfaces or spherical particles, such strategies cannot be used to simplify the interactions between faceted particles due to their more complex geometries."

To skirt around this issue, Lee and Arya took a different approach by making several simplifications. The first step involves representing the particle as being made up not of cubic elements, but of rod-shaped elements of various lengths stacked together. The model then assumes that rods whose projections fall outside the projected boundary of the other particle contribute negligibly to the overall interaction energy.

The energies contributed by the remaining rods are further assumed to equal the energies of rods of uniform lengths located the same normal distance as the actual rods, but with zero lateral offset. The final trick is to approximate the distance-dependence of the rod-particle energy using power-law functions that have closed-form solutions when distances vary linearly with the lateral position of the actual rods, as is case with the flat interacting surfaces of faceted particles.

After all of these simplifications are made, analytical solutions for the interparticle energies can be obtained, allowing a computer to breeze through them. And while it may sound like they would introduce a large amount of error, the researchers found that the results were only 8% off on average from the actual answer for all particle configurations, and only 25% different at their worst.

While the researchers primarily worked with cubes, they also showed that the approach works with triangular prisms, square rods and square pyramids. Depending on the shape and material of the nanoparticles, the modeling approach could impact a wide range of fields. For example, silver or gold nanocubes with edges close to one another can harness and focus light into tiny "hotspots," creating an opportunity for better sensors or catalyzing chemical reactions.

"This is the first time that anyone has proposed an analytical model for van der Waals interactions between faceted particles," said Arya. "Even though we are yet to apply it for computing interparticle forces or energies within molecular dynamics or Monte Carlo simulations of particle assembly, we expect the model to speed up such simulations by as much as ten orders of magnitude."

Reno, Nev. (Nov. 19, 2020) - Climate change and a "thirsty atmosphere" will bring more extreme wildfire danger and multi-year droughts to Nevada and California by the end of this century, according to new research from the Desert Research Institute (DRI), the Scripps Institution of Oceanography at the University of California, San Diego, and the University of California, Merced.

In a new study published in Earth's Future, scientists looked at future projections of evaporative demand - a measure of how dry the air is - in California and Nevada through the end of the 21st century. They then examined how changes in evaporative demand would impact the frequency of extreme fire danger and three-year droughts, based on metrics from the Evaporative Demand Drought Index (EDDI) and the Standardized Precipitation Evapotranspiration Index (SPEI).

According to their results, climate change projections show consistent future increases in atmospheric evaporative demand (or the "atmospheric thirst") over California and Nevada. These changes were largely driven by warmer temperatures, and would likely lead to significant on-the-ground environmental impacts.

"Higher evaporative demand during summer and autumn--peak fire season in the region--means faster drying of soil moisture and vegetation, and available fuels becoming more flammable, leading to fires that can burn faster and hotter," explained lead author Dan McEvoy, Ph.D., Assistant Research Professor of Climatology at DRI.

"Increased evaporative demand with warming enables fuels to be drier for longer periods," added coauthor John Abatzoglou, Ph.D., Associate Professor with the University of California, Merced. "This is a recipe for more active fire seasons."

The research team found that days with extreme fire danger in summer and autumn are expected to increase four to 10 times by the end of the century. Their results also showed that multi-year droughts, similar to that experienced in California and Nevada during 2012-2016, were projected to increase three to 15 times by the end of the century.

"One major takeaway was that we can expect to see a lot more days in the summer and autumn with extreme fire danger related to increased temperature and evaporative demand," McEvoy said. "Another takeaway was that even in locations where precipitation may not change that much in future, droughts are going to become more severe due to higher evaporative demand."

Study authors say that the cumulative effects of increases in evaporative demand will stress native ecosystems, increase fire danger, negatively impact agriculture where water demands cannot be met, and exacerbate impacts to society during periods of prolonged dryness. Several members of the research team are part of the California-Nevada Applications Program (CNAP), and will use these study results to provide resource managers with a view of possible future scenarios.

"These results provide information to support science-based, long-term planning for fire management agencies, forest management agencies, and water resource managers," said coauthor Julie Kalansky, Ph.D., Program Manager for CNAP. "We plan to work with partners to help integrate the findings from this paper to support building climate resilience."

An international research team led by UK scientists has revealed the return of critically endangered Antarctic blue whales to the sub-Antarctic island of South Georgia, 50 years after whaling all but wiped them out. The new study follows recent research that humpback whales are also returning to the region.

The discovery, based on analysis of 30 years' worth of sightings, photographs and underwater sound recordings, is crucial evidence in learning how the species is recovering following a ban on commercial whaling in the 1960s. The findings are published today (19 November) in the journal Endangered Species Research.

Blue whales were abundant off South Georgia before early 20th century industrial whaling between 1904 and 1971 killed 42,698 of them there. Most of these were killed before the mid-1930s.

The species all but vanished from the region - dedicated whale surveys from ships off South Georgia resulted in only a single blue whale sighting between 1998 and 2018 - but more recent surveys suggest blue whales are making a comeback.

A 2020 survey in February resulted in 58 blue whale sightings, and numerous acoustic detections.

Lead author Susannah Calderan of the Scottish Association for Marine Science (SAMS), Oban said: "The continued absence of blue whales at South Georgia has been seen as an iconic example of a population that was locally exploited beyond the point where it could recover.

"But over the past few years we've been working at South Georgia, we have become quite optimistic about the numbers of blue whales seen and heard around the island, which hadn't been happening until very recently. This year was particularly exciting, with more blue whale sightings than we ever could have hoped for."

As well as looking for whales, the researchers used listening devices, which can detect the loud, low frequency calls of whales over long distances and can also work in rough weather. The team also had records of whale sightings reported to the South Georgia Museum by mariners and tourist ship passengers, and photographs of blue whales, which enable individual animals to be identified.

In total, 41 blue whales have been photo-identified from South Georgia between 2011 and 2020, although none of these matched the 517 whales in the current Antarctic blue whale photographic catalogue.

Susannah Calderan added: "We don't quite know why it has taken the blue whales so long to come back. It may be that so many of them were killed at South Georgia that there was a loss of cultural memory in the population that the area was a foraging ground, and that it is only now being rediscovered."

There are limited opportunities for dedicated whale surveys in the region, known for its harsh weather and inaccessibility but such surveys are crucial to the future management of South Georgia's seas.

Co-author and whale ecologist Dr Jennifer Jackson of British Antarctic Survey, who led the 2020 whale expedition, said: "This is an exciting discovery and a really positive step forward for conservation of the Antarctic blue whale.

"With South Georgia waters designated as a Marine Protected Area by the Government of South Georgia and the South Sandwich Islands, we hope that these increased numbers of blue whales are a sign of things to come and that our research can continue to contribute to effective management of the area."

Peer-reviewed / Randomised Controlled Trial / People

**There will be a UK Science Media Centre briefing at 10.15am UK time on Thursday 19th November about this study. Please see details in notes to editors**

Older adults are at a disproportionate risk of severe COVID-19 disease, so it is essential that any vaccine adopted for use against SARS-CoV-2 is effective in this group

Study of 560 healthy adults - including 240 over the age of 70 years - presents preliminary findings on safety and immune responses of the ChAdOx1 nCoV-19 vaccine

Results show that the vaccine is better tolerated in older people compared to younger adults, and produces a similar immune response in old and young adults

Authors note that their new findings could be encouraging if the immune responses found in their study are associated with protection against infection with SARS-CoV-2, but this study did not assess efficacy and phase 3 trials are ongoing to confirm this.

The UK's vaccine against SARS-CoV-2 shows similar safety and immunogenicity results in healthy older adults (aged 56 years and over) to those seen in adults aged 18-55 years. The promising early stage results are published in The Lancet.

The phase 2 trial finds that the vaccine causes few side effects, and induces immune responses in both parts of the immune system in all age groups and at low and standard dose - provoking a T cell response within 14 days of the first dose of vaccination (ie, a cellular immune response, it could find and attack cells infected with the virus), and an antibody response within 28 days of the booster dose of vaccination (ie, humoral immune response, it could find and attack the virus when it was circulating in the blood or lymphatic system). Phase 3 trials are ongoing to confirm these results - as well as how effective the vaccine is in protecting against infection with SARS-CoV-2 - in a broader range of people, including older adults with underlying health conditions.

Study lead author Professor Andrew Pollard, University of Oxford, UK, says: "Immune responses from vaccines are often lessened in older adults because the immune system gradually deteriorates with age, which also leaves older adults more susceptible to infections. As a result, it is crucial that COVID-19 vaccines are tested in this group who are also a priority group for immunisation." [1]

Co-author Dr Maheshi Ramasamy, University of Oxford, UK, adds: "The robust antibody and T-cell responses seen in older people in our study are encouraging. The populations at greatest risk of serious COVID-19 disease include people with existing health conditions and older adults. We hope that this means our vaccine will help to protect some of the most vulnerable people in society, but further research will be needed before we can be sure." [1]

The new study is the fifth published clinical trial of a vaccine against SARS-CoV-2 tested in an older adult population. Other COVID-19 vaccines have also been shown to generate immune responses in older adults, but it can be difficult to compare results between different studies. One study has shown similar immune responses in young and old adults (Moderna mRNA vaccine), while other trials have suggested lower measured responses in older adults, compared to younger adults receiving the same vaccine (CanSino single dose adenovirus-vector vaccine, Pfizer/BioNTech mRNA vaccine, and SinoPharm/Beijing Institute of Biological Products inactivated viral vaccine).

In the phase 2 trial published today, 560 participants (160 aged 18-55 years, 160 aged 56-69 years, and 240 aged 70 or over) were split into 10 groups [2] where they received either the ChAdOx1 nCoV-19 vaccine at a low or standard dose, or a control vaccine (the meningococcal conjugate vaccine). Participants aged over 55 years were also split into groups and either given a single dose of vaccine, or two doses 28 days apart.

Study recruitment occurred during a national lockdown in the UK when vulnerable individuals were advised to self-isolate. For this reason, the study includes only healthy participants and not those with co-morbidities or who are frail. Before receiving the vaccine, all participants had a blood test to determine if they had previously been infected with SARS-CoV-2. Those who had antibodies for SARS-CoV-2 were excluded, except for 18-55-year-olds in the standard dose double vaccine groups.

Following vaccination, participants were observed for a minimum of 15 minutes in case of any immediate adverse events, and participants recorded any adverse events for seven days afterwards. Participants will continue to be monitored for any serious adverse events for one year following final vaccination (the year long data are not yet available).

Participants aged 18-55 years who received two standard doses of the Oxford COVID-19 vaccine and all participants aged 56 years or over had their immune responses assessed on the day of vaccination, then 1, 2 and 4 weeks after their first and second vaccination.

Adverse reactions to the ChAdOx1 nCoV-19 vaccine were mild (the most common effects were injection-site pain and tenderness, fatigue, headache, feverishness and muscle pain), but more common than seen with the control vaccine. Thirteen serious adverse events occurred in the six months since the first dose was given, none of which were related to either study vaccine.

Adverse effects were less common in older adults than in younger adults (within seven days of one standard dose of ChAdOx1 nCoV-19, local symptoms such as temporary pain, tenderness, redness, and swelling at the site of the injection occurred in 88%, 43/49 18-55 year olds, 73%, 22/30 56-69 year olds, and 61%, 30/49 people aged 70 or over. Within 7 days of injection, systemic symptoms such as temporary fatigue, headache, malaise, feverishness, and muscle aches occurred in 86%, 42/49 18-55 year olds, 77%, 23/30 56-69 year olds, and 65%, 32/49 people aged 70 or over), and similar levels of local symptoms were seen after the first and booster doses of the Oxford COVID-19 vaccine in older adults, while there were few systemic symptoms following the booster dose.

The COVID-19 vaccine had similar immunogenicity across all age groups after a boost dose.

The ChAdOx1 nCoV-19 vaccine induced antibodies against the SARS-CoV-2 spike protein and receptor binding domain 28 days after a single low or standard dose across all age groups. Following the booster dose of the vaccine, antibody levels increased at day 56 of the trial, irrespective of dose or participant age. The same was seen with levels of neutralising antibodies at day 42, two weeks after the booster vaccine dose. By 14 days after the boost dose, 208 of 209 (more than 99%) participants (selected from participants of all ages and doses) had neutralising antibody responses.

T cell responses against the SARS-CoV-2 spike protein peaked 14 days after first vaccination, regardless of age and low or standard vaccine dose.

Co-author, Professor Sarah Gilbert, University of Oxford, UK, says: "The WHO has outlined a number of critical factors for COVID-19 vaccines, including that they must be targeted at the most at-risk groups including older adults. They must also be safe, effective in preventing disease and/or transmission, and provide at least six months of protection for people frequently exposed to the virus - such as healthcare workers. Our new study answers some of these questions about protecting older adults, but questions remain about effectiveness and length of protection, and we need to confirm our results in older adults with underlying conditions to ensure that our vaccine protects those most at risk of severe COVID-19 disease." [1]

The authors note some limitations to their study, including that the participants in the oldest age group had an average age of 73-74 years and few underlying health conditions, so may not be representative of the general older population, including those living in residential care settings or over 80 years of age. Larger studies are now underway to evaluate immunogenicity, safety and efficacy in older adults with a wider range of comorbidities. Lastly, the authors note that almost all participants of all ages were white and non-smokers, and may not be representative of the general population, but people from a range of backgrounds, countries and ethnicities are being included in the phase 3 trial of this vaccine.

Writing in a linked Comment, lead author Dr Melissa Andrew, Dalhousie University, Canada, who was not involved in the study, says: "It is encouraging that more studies in older adult populations are underway and will hopefully bring opportunities to implement nuanced analyses of how underlying health status and frailty affect vaccine safety, reactogenicity, immunogenicity, and efficacy in older adults in real-world settings. Older adults (across the full spectrum of frailty) and those who care about them are eagerly awaiting this progress towards safe and effective COVID-19 vaccines."

A new study of Canadians aged 45-85, released this week in the International Journal of Social Psychiatry, found that 24% of refugees were in psychological distress compared to 13% of non-refugee immigrants and those born in Canada.

"Refugees are very vulnerable to negative mental health in later life. The average time these refugees had lived in Canada was more than 4 decades, yet one in four were still in substantial psychological distress," says the study's first author Hongmei Tong, Assistant Professor of Social Work at MacEwan University in Edmonton.

"Since refugees had twice the prevalence of distress compared to other immigrants, we hypothesize that pre-migration traumas, rather than the post-migration challenges of resettlement, are probably driving the high levels of psychological distress" says Tong.

The researchers found that individuals without social support were twice as likely to experience psychological distress compared to those with at least some social support. In addition, more than one-quarter of the refugees in the study did not have someone they could regularly confide in, nor someone they could turn to for advice in a crisis. Almost one in five refugees had no one who regularly showed them love or attention. Immigrants who were not refugees and those born in Canada were much less likely to lack these key aspects of social support.

"We believe this extreme lack of social support may be a contributing factor to refugees' increased vulnerability to distress," says senior author, Esme Fuller-Thomson, director of the Institute for Life Course & Aging and professor at the University of Toronto's Factor-Inwentash Faculty of Social Work (FIFSW). "These findings underline the importance of finding effective interventions to help refugees integrate into their community and develop supportive relationships."

Consistent with earlier studies, older Canadian adults in this study who were less educated, poor, experiencing chronic pain and those with more co-morbid health conditions had a higher prevalence of psychological distress.

"Mental health professionals must be careful not to neglect physical health concerns such as chronic health conditions and chronic pain." says co-author Yu Lung, a doctoral candidate at the University of Toronto's FIFSW.

The study also found that in the general population women and visible minority members are at a higher risk of psychological distress than men and whites.

"Programs to address mental health concerns should target the groups in these higher risk categories," says co-author Karen Kobayashi, a professor in the Department of Sociology and a research fellow at the Institute on Aging & Lifelong Health at the University of Victoria.

The study's findings have important policy implications.

"With such a high prevalence of distress among older refugees, there is a need to screen for depression and to provide trauma informed mental health interventions for those who are struggling," says co-author Karen Davison, Health Science Faculty and Nutrition Informatics Research Program Director at Kwantlen Polytechnic University in Surrey, B.C.

This study was published online, ahead of print, in the International Journal of Social Psychiatry this month. It uses data from the Canadian Longitudinal Study on Aging and includes information on 244 refugees, 4,765 non-refugee immigrants and 23,149 respondents born in Canada.

In recent years, big data sets from mobile phones have been used to provide increasingly accurate analyses of how we all move between home, work, and leisure, holiday and everything else. The strength of basing analyses on mobile phone data is that they provide accurate data on when, how, and how far each individual moves without any particular focus on whether they are passing geographical boundaries along the way--we simply move from one coordinate to another in a system of longitude and latitude.

"The problem with existing big data models however is that they do not capture what geographical structures such as neighbourhoods, towns, cities, regions, countries etc. mean for our mobility. This makes it difficult, for example, to generate good models for future mobility. And it is insights of this kind we need when new forms of transport crop up, or when urbanization takes hold," explains Sune Lehmann, professor at DTU and at the University of Copenhagen.

In fact, the big data approach to modelling location data has erased the usual dimensions that characterize geographical areas and their significance for our daily journeys and patterns of movement. In mobility research, these are known as scales.

"Within mobility research, things are sometimes presented as if scale does not come into the equation. At the same time, however, common sense tells us that there have to be typical trips or patterns of movement, which are determined by geography. Intuitively it seems wrong that you cannot see, for example, that a neighbourhood or urban zone has a typical area. A neighbourhood is a place where you can go down and pick up a pizza or buy a bag of sweets. It doesn't make sense to have a neighbourhood the size of a small country. Geography must play a role. It's a bit of a paradox," says Laura Alessandretti, Assistant Professor at DTU and University of Copenhagen

Finds new, natural, and flexible geographical boundaries

The authors of the article have therefore developed a new mathematical model that defines new geographical scales from mobile tracking data, and which in this way brings the geography--the usual sizes and length --back to our understanding of mobility.

The model uses anonymized mobile data from more than 700,000 individuals worldwide and identifies scales--neighbourhoods, towns, cities, regions, countries--for each person based on their movement data.

"And if you look at the results, it's clear that distance plays a role in our patterns of movement, but that when it comes to travel there are typical distances and choices that correspond to geographical boundaries--only it's not the same boundaries you can find on a map. And to make it all a bit more complex, 'our geographical areas' also change depending on who we are. If you live on the boundary between city districts, your neighbourhood is located with, for example, a centre where you live and includes parts of both city districts. Our model also shows that who we are plays a role. The size of a neighbourhood varies depending on whether you are male, female, young, or old. Whether you live in the city or the countryside, or whether you live in Saudi Arabia or the UK," explains Sune Lehmann.

Important for the green transition and combating epidemics

The new model provides a more nuanced and accurate picture of how we move around in different situations and, not least, it makes it possible to predict mobility in relation to geographical developments in general. This has implications for some of society's most important decisions:

"Better models of mobility are important. For example, in traffic planning, in the transport sector, and in the fight against epidemics. We can save millions of tonnes of CO2, billions of dollars and many lives by using the most precise models when planning the society of the future," says Ulf Aslak Jensen, Post Doc at DTU and Copenhagen University

Fact box: The boarders move depending on who you are

In the article, the researchers use i.a. the model to study mobility differences in different population groups in 53 countries. Among other things, they find that:

Women in 21 of the 53 countries surveyed daily switch between more geographical levels than men

Women move within smaller distances than men

The local areas of the rural population are larger than those of the urban population.

A continuous 10,000-year record of alpine glacier fluctuations in Wyoming's Teton Range suggests that some glacial ice in the western U.S. persisted in a reduced, essentially dormant state during periods of early Holocene warming. The findings challenge the paradigm that all Rocky Mountain glaciers completely disappeared during these warm, dry conditions, instead indicating that they may have taken the form of smaller glaciers covered by debris or caked with rocks, which insulated the lingering ice from the heat. This insight may help scientists better understand how glaciers in the region may respond to future warming. "The long-term survival of glacial ice through warm conditions highlights the potential role of debris-covered glaciers and/or rock glaciers to continue providing ecosystem services into the future, despite unfavorable climatic conditions," says Darren Larsen, the lead author of the study. Retreating glaciers are a hallmark of modern climate change, but due to an incomplete glacial record, little is known about how western U.S. glaciers responded to temperature and precipitation changes thousands of years ago. To construct a continuous record, Larsen and colleagues sampled sediment cores from two lake basins in the Tetons - Delta Lake, a glacial lake basin that provided a complementary record of glacier activity, and other nearby lakes including Surprise Lake, a nonglacial lake basin that provided a record of climate variability. By using accelerator mass spectrometry radiocarbon dating, the researchers developed composite rock layer sequences that documented changes in the glaciers as they endured shifts in climate over ten millennia. While sediment flux and meltwater from the Teton Glacier appeared to decrease during a warm period between about 10,000 and 6,300 years ago, Delta Lake sediments maintained distinctly glacial characteristics that suggest glacial ice remained.