Algorithms inspired by social networks reveal lifecycle of substorms, a key element of space weather

 Space weather often manifests as substorms, where a beautiful auroral display such as the Northern Lights is accompanied by an electrical current in space which has effects at earth that can interfere with and damage power distribution and electrical systems. Now, the lifecycle of these auroral substorms has been revealed using social media-inspired mathematical tools to analyse space weather observations across the Earth's surface.

Analysis by researchers led by the University of Warwick has revealed that these substorms manifest as global-scale electrical current systems associated with the spectacular aurora, reaching across over a third of the globe at high latitudes.

New research which involves the University of Warwick, John Hopkins University -- Applied Physics Laboratory, University of Bergen and Cranfield University, and published today (23 March) in the journal Nature Communications processes data on disturbances in the Earth's magnetic field from over a hundred magnetometers in the Northern hemisphere using a new technique that enables them to find 'like-minded friends'.

Magnetometers register changes in the Earth's magnetic field. When charged particles from our Sun bombard the Earth's magnetic field, it stores up energy like a battery. Eventually, this energy is released leading to large-scale electrical currents in the ionosphere which generate disturbances of magnetic fields on the ground. At extremes, this can disrupt power lines, electronic and communications systems and technologies such as GPS.

Using historical data from the SuperMAG collaboration of magnetometers, the researchers applied algorithms from network science to find correlations between magnetometer signals during 41 known substorms that occurred between 1997-2001. These use the same principles that allow a social networking site to recommend new friends, or to push relevant advertisements to you as you browse the internet.

Magnetometers detecting coherent signals were linked into communities, regardless of where they were located on the globe. As time progressed, they saw each substorm develop from many smaller communities into a single large correlated system or community at its peak. This led the authors to conclude that substorms are one coherent current system which extends over most of the nightside high latitude globe, rather than a number of individual small and disjointed current systems.

Dr Lauren Orr, who led the research as part of her PhD at the University of Warwick Department of Physics and is now based at Lancaster University, said: "We used a well-established method within network science called community detection and applied it to a space weather problem. The idea is that if you have lots of little subgroups within a big group, it can pick out the subgroups.

"We applied this to space weather to pick out groups within magnetometer stations on the Earth. From that, we were trying to find out whether there was one large current system or lots of separate individual current systems.

"This is a good way of letting the data tell us what's going on, instead of trying to fit observations to what we think is occurring."

Some recent work has suggested that auroral substorms are composed of a number of smaller electrical current systems and remain so throughout their lifecycle. This new research demonstrates that while the substorm begins as lots of smaller disturbances, it quite rapidly becomes a large system over the course of around ten minutes. The lack of correlation in its early stages may also suggest that there is no single mechanism at play in how these substorms evolve.

The results have implications for models designed to predict space weather. Space weather was included in the UK National Risk Register in 2012 and updated in 2017 with a recommendation for more investment in forecasting.

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Babies prefer baby talk, whether they're learning one language or two

 It can be hard to resist lapsing into an exaggerated, singsong tone when you talk to a cute baby. And that's with good reason. Babies will pay more attention to baby talk than regular speech, regardless of which languages they're used to hearing, according to a study by UCLA's Language Acquisition Lab and 16 other labs around the globe.

The study found that babies who were exposed to two languages had a greater interest in infant-directed speech -- that is, an adult speaking baby talk -- than adult-directed speech. Research has already shown that monolingual babies prefer baby talk.

Some parents worry that teaching two languages could mean an infant won't learn to speak on time, but the new study shows bilingual babies are developmentally right on track. The peer-reviewed study, published today by Advances in Methods and Practices in Psychological Science, found bilingual babies became interested in baby talk at the same age as those learning one language.

"Crucially for parents, we found that development of learning and attention is similar in infants, whether they're learning one or two languages," said Megha Sundara, a UCLA linguistics professor and director of the Language Acquisition Lab. "And, of course, learning a language earlier helps you learn it better, so bilingualism is a win-win."

In the study, which took place at 17 labs on four continents, researchers observed 333 bilingual babies and 384 monolingual babies, ranging in age from 6 to 9 months and 12 to 15 months. UCLA's lab was the only one to provide data on bilingual babies who grew up hearing both English and Spanish. Sundara and Victoria Mateu, a UCLA assistant professor of Spanish and Portuguese, observed babies who were 12 to 15 months old.

Each baby would sit on a parent's lap while recordings of an English-speaking mother, using either infant-directed speech or adult-directed speech, played from speakers on the left or the right. Computer tracking measured how long each baby looked in the direction of each sound.

"The longer they looked, the stronger their preference," Mateu said. "Babies tend to pay more attention to the exaggerated sounds of infant-directed speech."

Infants' interest in English baby talk was very fine-tuned, the study noted. Bilingual parents indicated the percent of time English was spoken at home compared to Spanish. The more English the bilingual babies had been exposed to, the stronger their preference for infant-directed speech compared to adult-directed speech. However, even babies with no exposure to English preferred the English baby talk to the grown-up talk, Mateu said.

Baby talk is found across most languages and cultures, but English has one of the most exaggerated forms, Sundara said.

"Baby talk has a slower rate of speech across all languages, with more variable pitch, and it's more animated and happy," she said. "It varies mainly in how exaggerated it is."

Led by Krista Byers-Heinlein, a psychology professor at Concordia University in Montreal, the study involved labs in the United States, Canada, Europe, Australia and Singapore. The study's global reach strengthened the results, Sundara said.

"When you do language research, you want to know that the results aren't just some quirk of the language you're studying," she said.

According to the study, 6- to 9-month-old babies who had mothers with higher levels of education preferred baby talk more than babies whose mothers had less education.

"We suspect that perhaps the mothers with higher education levels spoke more to the babies and used infant-directed speech more often," Mateu said.

This study is one of the first published by the ManyBabies Consortium, a multi-lab group of researchers. Byers-Heinlein believes the unusual international, multilingual collaboration creates a model for future studies that include a similar breadth of languages and cultures.

"We can really make progress in understanding bilingualism, and especially the variability of bilingualism, thanks to our access to all these different communities," she said.

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'Zombie' genes? Research shows some genes come to life in the brain after death

 In the hours after we die, certain cells in the human brain are still active. Some cells even increase their activity and grow to gargantuan proportions, according to new research from the University of Illinois Chicago.

In a newly published study in the journal Scientific Reports, the UIC researchers analyzed gene expression in fresh brain tissue -- which was collected during routine brain surgery -- at multiple times after removal to simulate the post-mortem interval and death. They found that gene expression in some cells actually increased after death.

These 'zombie genes' -- those that increased expression after the post-mortem interval -- were specific to one type of cell: inflammatory cells called glial cells. The researchers observed that glial cells grow and sprout long arm-like appendages for many hours after death.

"That glial cells enlarge after death isn't too surprising given that they are inflammatory and their job is to clean things up after brain injuries like oxygen deprivation or stroke," said Dr. Jeffrey Loeb, the John S. Garvin Professor and head of neurology and rehabilitation at the UIC College of Medicine and corresponding author on the paper.

What's significant, Loeb said, is the implications of this discovery -- most research studies that use postmortem human brain tissues to find treatments and potential cures for disorders such as autism, schizophrenia and Alzheimer's disease, do not account for the post-mortem gene expression or cell activity.

"Most studies assume that everything in the brain stops when the heart stops beating, but this is not so," Loeb said. "Our findings will be needed to interpret research on human brain tissues. We just haven't quantified these changes until now."

Loeb and his team noticed that the global pattern of gene expression in fresh human brain tissue didn't match any of the published reports of postmortem brain gene expression from people without neurological disorders or from people with a wide variety of neurological disorders, ranging from autism to Alzheimer's.

"We decided to run a simulated death experiment by looking at the expression of all human genes, at time points from 0 to 24 hours, from a large block of recently collected brain tissues, which were allowed to sit at room temperature to replicate the postmortem interval," Loeb said.

Loeb and colleagues are at a particular advantage when it comes to studying brain tissue. Loeb is director of the UI NeuroRepository, a bank of human brain tissues from patients with neurological disorders who have consented to having tissue collected and stored for research either after they die, or during standard of care surgery to treat disorders such as epilepsy. For example, during certain surgeries to treat epilepsy, epileptic brain tissue is removed to help eliminate seizures. Not all of the tissue is needed for pathological diagnosis, so some can be used for research. This is the tissue that Loeb and colleagues analyzed in their research.

They found that about 80% of the genes analyzed remained relatively stable for 24 hours -- their expression didn't change much. These included genes often referred to as housekeeping genes that provide basic cellular functions and are commonly used in research studies to show the quality of the tissue. Another group of genes, known to be present in neurons and shown to be intricately involved in human brain activity such as memory, thinking and seizure activity, rapidly degraded in the hours after death. These genes are important to researchers studying disorders like schizophrenia and Alzheimer's disease, Loeb said.

A third group of genes -- the 'zombie genes' -- increased their activity at the same time the neuronal genes were ramping down. The pattern of post-mortem changes peaked at about 12 hours.

"Our findings don't mean that we should throw away human tissue research programs, it just means that researchers need to take into account these genetic and cellular changes, and reduce the post-mortem interval as much as possible to reduce the magnitude of these changes," Loeb said. "The good news from our findings is that we now know which genes and cell types are stable, which degrade, and which increase over time so that results from postmortem brain studies can be better understood."

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Rare genetic variant puts some younger men at risk of severe COVID-19

 A study of young men with COVID-19 has revealed a genetic variant linked to disease severity.

The discovery, published recently in eLife, means that men with severe disease could be genetically screened to identify who has the variant and may benefit from interferon treatment.

For most people, COVID-19, the disease caused by the virus SARS-CoV-2, causes only mild or no symptoms. However, severe cases can rapidly progress towards respiratory distress syndrome.

"Although older age and the presence of long-term conditions such as cardiovascular disease or diabetes are known risk factors, they alone do not fully explain differences in severity," explains first author Chiara Fallerini, Research Fellow in Medical Genetics at the Department of Medical Biotechnologies, University of Siena, Italy. "Some younger men without pre-existing medical conditions are more likely to be hospitalised, admitted to intensive care and to die of COVID-19, which suggests that some factors must cause a deficiency in their immune system."

Recent research has suggested that genes controlling interferon are important in regulating the immune response to COVID-19. Interferon is produced by immune cells during viral infection. It works alongside molecules on the surface of immune cells called Toll-like receptors (TLR) which detect viruses and kickstart the immune response. "When a recent study identified rare mutations in a TLR gene, TLR7, in young men with severe COVID-19, we wanted to investigate whether this was an ultra-rare situation or just the tip of the iceberg," says co-senior author Mario Mondelli, Professor of Infectious Diseases at the Division of Clinical Immunology and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Italy.

The team studied a subset of 156 male COVID-19 patients younger than 60 years old, selected from a large multicentre study in Italy, called GEN-COVID, which started its activity on March 16, 2020. GEN-COVID is a network of more than 40 Italian hospitals coordinated by co-senior author Alessandra Renieri, Full Professor of Medical Genetics at the University of Siena, and Director of Medical Genetics at Azienda Ospedaliero-Universitaria Senese, Siena, Italy.

The team first analysed all the genes on the X chromosome of men with both mild and severe cases of COVID-19, and identified the TLR7 gene as one of the most important genes linked to disease severity. They then searched the entire GEN-COVID database, and selected for younger men (less than 60 years old). This identified rare TLR7 missense mutations in five of 79 patients (6.3%) with life-threatening COVID-19 and no similar mutations in the 77 men who had few symptoms. They also found the same mutation in three men aged over 60: two who had severe COVID-19 and one who had few symptoms -- although the mutation found in the man with few symptoms had little effect on TLR function.

To link these mutations to the immune cell response, they treated white blood cells from recovered patients with a drug that switches TLR7 genes on. They found that the TLR7 genes were dampened down in immune cells from patients with mutations, compared to the TLR7 activity seen in normal immune cells. They also found lower levels of interferon in the cells containing the mutation compared to normal white blood cells. This confirmed that the mutations identified directly affect the control of interferon as part of the innate immune response.

To confirm the impact of the mutations on COVID-19 response, the team studied two brothers, one with a mutation in an interferon gene and one without. The levels of interferon gene activity were much lower in the man with the missense mutation, compared with his brother. Moreover, the brother with the mutation had severe COVID-19, while his brother with normal interferon genes was asymptomatic.

"Our results show that young men with severe COVID-19 who have lost function in their interferon-regulating genes represent a small but important subset of more vulnerable COVID-19 patients," says co-senior author Elisa Frullanti, Researcher of Medical Genetics at the University of Siena.

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Researchers create map of potential undiscovered life

 Less than a decade after unveiling the "Map of Life," a global database that marks the distribution of known species across the planet, Yale researchers have launched an even more ambitious and perhaps important project -- creating a map of where life has yet to be discovered.

For Walter Jetz, a professor of ecology and evolutionary biology at Yale who spearheaded the Map of Life project, the new effort is a moral imperative that can help support biodiversity discovery and preservation around the world.

"At the current pace of global environmental change, there is no doubt that many species will go extinct before we have ever learned about their existence and had the chance to consider their fate," Jetz said. "I feel such ignorance is inexcusable, and we owe it to future generations to rapidly close these knowledge gaps."

The new map of undiscovered species was published March 22 in the journal Nature Ecology & Evolution.

Lead author Mario Moura, a former Yale postdoctoral associate in Jetz's lab and now professor at Federal University of Paraiba, said the new study shifts the focus from questions like "How many undiscovered species exist?" to more applied ones such as "Where and what?"

"Known species are the 'working units' in many conservation approaches, thus unknown species are usually left out of conservation planning, management, and decision-making," Moura said. "Finding the missing pieces of the Earth's biodiversity puzzle is therefore crucial to improve biodiversity conservation worldwide."

According to conservative scientific estimates, only some 10 to 20 percent of species on earth have been formally described. In an effort to help find some of these missing species, Moura and Jetz compiled exhaustive data that included the location, geographical range, historical discovery dates, and other environmental and biological characteristics of about 32,000 known terrestrial vertebrates. Their analysis allowed them to extrapolate where and what kinds of unknown species of the four main vertebrate groups are most likely to yet be identified.

They looked at 11 key factors which allowed the team to better predict locations where undiscovered species might be located. For instance, large animals with wide geographical ranges in populated areas are more likely to have already been discovered. New discoveries of such species are likely to be rare in the future. However, smaller animals with limited ranges who live in more inaccessible regions are more likely to have avoided detection so far.

"The chances of being discovered and described early are not equal among species," Moura said. For instance, the emu, a large bird in Australia, was discovered in 1790 soon after taxonomic descriptions of species began. However, the small, elusive frog species Brachycephalus guarani wasn't discovered in Brazil until 2012, suggesting more such amphibians remain to be found.

Moura and Jetz show that the chances of new species discovery varies widely across the globe. Their analysis suggests Brazil, Indonesia, Madagascar, and Colombia hold the greatest opportunities for identifying new species overall, with a quarter of all potential discoveries. Unidentified species of amphibians and reptiles are most likely to turn up in neotropical regions and Indo-Malayan forests.

Moura and Jetz also focused on another key variable in uncovering missing species -- the number of taxonomists who are looking for them.

"We tend to discover the 'obvious' first and the 'obscure' later," Moura said. "We need more funding for taxonomists to find the remaining undiscovered species."

But the global distribution of taxonomists is greatly uneven and a map of undiscovered life can help focus new efforts, Jetz noted. That work will become increasingly important as nations worldwide gather to negotiate a new Global Biodiversity Framework under the Convention of Biological Diversity later this year and make commitments to halting biodiversity loss.

"A more even distribution of taxonomic resources can accelerate species discoveries and limit the number of 'forever unknown' extinctions," Jetz said.

With partners worldwide, Jetz and colleagues plan to expand their map of undiscovered life to plant, marine, and invertebrate species in the coming years. Such information will be help governments and science institutions grapple with where to concentrate efforts on documenting and preserving biodiversity, Jetz said.

Read more at Science Daily

Researchers tackle the 'spiders' from Mars

 Researchers at Trinity College Dublin have been shedding light on the enigmatic "spiders from Mars," providing the first physical evidence that these unique features on the planet's surface can be formed by the sublimation of CO2 ice.

Spiders, more formally referred to as araneiforms, are strange-looking negative topography radial systems of dendritic troughs; patterns that resemble branches of a tree or fork lightning. These features, which are not found on Earth, are believed to be carved into the Martian surface by dry ice changing directly from solid to gas (sublimating) in the spring. Unlike Earth, Mars' atmosphere comprises mainly of CO2 and as temperatures decrease in winter, this deposits onto the surface as CO2 frost and ice.

The Trinity team, along with colleagues at Durham University and the Open University, conducted a series of experiments funded by the Irish Research Council and Europlanet at the Open University Mars Simulation Chamber, under Martian atmospheric pressure, in order to investigate whether patterns similar to Martian spiders could form by dry ice sublimation.

Its findings are detailed in a paper recently published in the Nature Journal, Scientific Reports.

Dr Lauren McKeown, who led this work during her PhD at Trinity and is now at the Open University, said:

"This research presents the first set of empirical evidence for a surface process that is thought to modify the polar landscape on Mars. Kieffer's hypothesis [explained below] has been well accepted for over a decade, but until now, it has been framed in a purely theoretical context.

"The experiments show directly that the spider patterns we observe on Mars from orbit can be carved by the direct conversion of dry ice from solid to gas. It is exciting because we are beginning to understand more about how the surface of Mars is changing seasonally today."

The research team drilled holes in the centres of CO2 ice blocks and suspended them with a claw similar to those found in arcades, above granular beds of different grain sizes. They lowered the pressure inside a vacuum chamber to Martian atmospheric pressure (6mbar) and then used a lever system to place the CO2 ice block on the surface.

They made use of an effect known as the Leidenfrost Effect, whereby if a substance comes in contact with a surface much hotter than its sublimation point, it will form a gaseous layer around itself. When the block reached the sandy surface, CO2 turned directly from solid to gas and material was seen escaping through the central hole in the form of a plume.

In each case, once the block was lifted, a spider pattern had been eroded by the escaping gas. The spider patterns were more branched when finer grain sizes were used and less branched when coarser grain sizes were used. This is the first set of empirical evidence for this extant surface process.

Dr Mary Bourke, of Trinity's Department of Geography, who supervised the PhD research, said:

"This innovative work supports the emergent theme that the current climate and weather on Mars has an important influence not only on dynamic surface processes, but also for any future robotic and/or human exploration of the planet."

The main hypothesis proposed for spider formation (Kieffer's hypothesis) suggests that in spring, sunlight penetrates this translucent ice and heats the terrain beneath it. The ice will sublimate from its base, causing pressure to build up and eventually the ice will rupture, allowing pressurised gas to escape through a crack in the ice. The paths of the escaping gas will leave behind the dendritic patterns observed on Mars today and the sandy/dusty material will be deposited on top of the ice in the form of a plume.

However, until now, it has not been known if such a theoretical process is possible and this process has never been directly observed on Mars.

Additionally, the researchers observed that when CO2 blocks were released and allowed to sublimate within the sand bed, sublimation was much more vigorous than expected and material was thrown all over the chamber.

This observation will be useful in understanding models of other CO2 sublimation-related processes on Mars, such as the formation of lateral Recurring Diffusive Flows surrounding linear dune gullies on Mars.

Read more at Science Daily

Health declining in Gen X and Gen Y, US study shows

 Recent generations show a worrying decline in health compared to their parents and grandparents when they were the same age, a new national study reveals.

Researchers found that, compared to previous generations, members of Generation X and Generation Y showed poorer physical health, higher levels of unhealthy behaviors such as alcohol use and smoking, and more depression and anxiety.

The results suggest the likelihood of higher levels of diseases and more deaths in younger generations than we have seen in the past, said Hui Zheng, lead author of the study and professor of sociology at The Ohio State University.

"The worsening health profiles we found in Gen X and Gen Y is alarming," Zheng said.

"If we don't find a way to slow this trend, we are potentially going to see an expansion of morbidity and mortality rates in the United States as these generations get older."

Zheng conducted the study with Paola Echave, a graduate student in sociology at Ohio State. The results were published yesterday (March 18, 2021) in the American Journal of Epidemiology.

The researchers used data from the National Health and Nutrition Examination Survey 1988-2016 (62,833 respondents) and the National Health Interview Survey 1997-2018 (625,221 respondents), both conducted by the National Center for Health Statistics.

To measure physical health, the researchers used eight markers of a condition called metabolic syndrome, a constellation of risk factors for heart disease, stroke, kidney disease and diabetes. Some of the markers include waist circumference, blood pressure, cholesterol level and body mass index (BMI). They also used one marker of chronic inflammation, low urinary albumin, and one additional marker of renal function, creatinine clearance.

The researchers found that the measures of physical health have worsened from the Baby Boomer generation through Gen X (born 1965-80) and Gen Y (born 1981-99). For whites, increases in metabolic syndrome were the main culprit, while increases in chronic inflammation were seen most in Black Americans, particularly men.

"The declining health trends in recent generations is a shocking finding," Zheng said. "It suggests we may have a challenging health prospect in the United State in coming years."

Zheng said it is beyond the scope of the study to comprehensively explain the reasons behind the health decline. But the researchers did check two factors. They found smoking couldn't explain the decline. Obesity could help explain the increase in metabolic syndrome, but not the increases seen in chronic inflammation.

It wasn't just the overall health markers that were concerning for some members of the younger generations, Zheng said.

Results showed that levels of anxiety and depression have increased for each generation of whites from the War Babies generation (born 1943-45) through Gen Y.

While levels of these two mental health indicators did increase for Blacks up through the early Baby Boomers, the rate has been generally flat since then.

Health behaviors also show worrying trends.

The probability of heavy drinking has continuously increased across generations for whites and Black males, especially after late-Gen X (born 1973-80).

For whites and Blacks, the probability of using street drugs peaked at late-Boomers (born 1956-64), decreased afterward, then rose again for late-Gen X. For Hispanics, it has continuously increased since early-Baby Boomers.

Surprisingly, results suggest the probability of having ever smoked has continuously increased across generations for all groups.

How can this be true with other research showing a decline in overall cigarette consumption since the 1970s?

"One possibility is that people in older generations are quitting smoking in larger numbers while younger generations are more likely to start smoking," Zheng said. "But we need further research to see if that is correct."

Zheng said these results may be just an early warning of what is to come.

"People in Gen X and Gen Y are still relatively young, so we may be underestimating their health problems," he said. "When they get older and chronic diseases become more prevalent, we'll have a better view of their health status."

Zheng noted that the United States has already seen recent decreases in life expectancy and increases in disability and morbidity.

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Bacteria may aid anti-cancer immune response

 Cancer immunotherapy may get a boost from an unexpected direction: bacteria residing within tumor cells. In a new study published in Nature, researchers at the Weizmann Institute of Science and their collaborators have discovered that the immune system "sees" these bacteria and shown they can be harnessed to provoke an immune reaction against the tumor. The study may also help clarify the connection between immunotherapy and the gut microbiome, explaining the findings of previous research that the microbiome affects the success of immunotherapy.

Immunotherapy treatments of the past decade or so have dramatically improved recovery rates from certain cancers, particularly malignant melanoma; but in melanoma, they still work in only about 40% of the cases. Prof. Yardena Samuels of Weizmann's Molecular Cell Biology Department studies molecular "signposts" -- protein fragments, or peptides, on the cell surface -- that mark cancer cells as foreign and may therefore serve as potential added targets for immunotherapy. In the new study, she and colleagues extended their search for new cancer signposts to those bacteria known to colonize tumors.

Using methods developed by departmental colleague Dr. Ravid Straussman, who was one of the first to reveal the nature of the bacterial "guests" in cancer cells, Samuels and her team, led by Dr. Shelly Kalaora and Adi Nagler (joint co-first authors), analyzed tissue samples from 17 metastatic melanoma tumors derived from nine patients. They obtained bacterial genomic profiles of these tumors and then applied an approach known as HLA-peptidomics to identify tumor peptides that can be recognized by the immune system.

The research was conducted in collaboration with Dr. Jennifer A. Wargo of the University of Texas MD Anderson Cancer Center, Houston, Texas; Prof Scott N. Peterson of Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California; Prof Eytan Ruppin of the National Cancer Institute, USA; Prof Arie Admon of the Technion -- Israel Institute of Technology and other scientists.

The HLA peptidomics analysis revealed nearly 300 peptides from 41 different bacteria on the surface of the melanoma cells. The crucial new finding was that the peptides were displayed on the cancer cell surfaces by HLA protein complexes -- complexes that are present on the membranes of all cells in our body and play a role in regulating the immune response. One of the HLA's jobs is to sound an alarm about anything that's foreign by "presenting" foreign peptides to the immune system so that immune T cells can "see" them. "Using HLA peptidomics, we were able to reveal the HLA-presented peptides of the tumor in an unbiased manner," Kalaora says. "This method has already enabled us in the past to identify tumor antigens that have shown promising results in clinical trials."

It's unclear why cancer cells should perform a seemingly suicidal act of this sort: presenting bacterial peptides to the immune system, which can respond by destroying these cells. But whatever the reason, the fact that malignant cells do display these peptides in such a manner reveals an entirely new type of interaction between the immune system and the tumor.

This revelation supplies a potential explanation for how the gut microbiome affects immunotherapy. Some of the bacteria the team identified were known gut microbes. The presentation of the bacterial peptides on the surface of tumor cells is likely to play a role in the immune response, and future studies may establish which bacterial peptides enhance that immune response, enabling physicians to predict the success of immunotherapy and to tailor a personalized treatment accordingly.

Moreover, the fact that bacterial peptides on tumor cells are visible to the immune system can be exploited for enhancing immunotherapy. "Many of these peptides were shared by different metastases from the same patient or by tumors from different patients, which suggests that they have a therapeutic potential and a potent ability to produce immune activation," Nagler says.

In a series of continuing experiments, Samuels and colleagues incubated T cells from melanoma patients in a laboratory dish together with bacterial peptides derived from tumor cells of the same patient. The result: T cells were activated specifically toward the bacterial peptides.

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Biofluorescent fish discovered in the Arctic

For the first time, scientists have documented biofluorescence in an Arctic fish species. The study, led by researchers at the American Museum of Natural History who spent hours in the icy waters off of Greenland where the red-and-green-glowing snailfish was found, is published today in the American Museum Novitates.

"Overall, we found marine fluorescence to be quite rare in the Arctic, in both invertebrate and vertebrate lineages," said John Sparks, a curator in the American Museum of Natural History's Department of Ichthyology and one of the authors of the study. "So we were surprised to find these juvenile snailfish brightly fluorescing in not just one, but two different colors, which is very unusual in a single species."

In 2014, Sparks and colleague David Gruber, a research associate at the Museum and a biology professor at Baruch College, identified more than 180 new species of fishes that biofluoresce, the ability to convert blue wavelengths into green, red, or yellow light. This ability, which could be used for behaviors including communication and mating in some species, is now well documented in tropical fishes that live in regions where there is an even amount of daylight year-round. But in the Arctic, where days can be incredibly long or incredibly short, researchers were interested in seeing firsthand how prolonged periods of darkness affected fishes' ability to biofluoresce.

"The light regime at the poles provides for winter months of near total darkness, where biofluorescence would not be functional," Gruber said. "But given the summer months with the midnight Sun, we hypothesized that it could be present."

In 2019, as part of a Constantine. S. Niarchos Expedition, Sparks and Gruber headed to the iceberg habitats off the coast of Eastern Greenland to test their theory. In addition to finding very little marine fluorescence, they observed that groups of fishes that glow brightly in tropical and temperate regions -- for example, scorpionfishes and flatfishes -- did not fluoresce in the cold waters. But there was an exception: two juvenile specimens of variegated snailfish (Liparis gibbus), the first species shown to biofluoresce in the Arctic. The species glows in both green and red, a rare example of multiple fluorescent colors emitted from a single organism. In addition, the authors report red biofluorescence from an adult kelp snailfish (L. tunicatus) collected in the Bering Strait off of Little Diomede Island, Alaska, which was collected and scanned by colleagues at NOAA Fisheries Service.

In the seven years since Sparks and Gruber first reported widespread biofluorescence in fishes, it has been found in a number of new lineages, including mammals like platypuses, opossums, flying squirrels, springhares, and even marine turtles. But its exact function remains a mystery.

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Muscle cramp? Drink electrolytes, not water

 If you reach for water when a muscle cramp strikes, you might want to think again. New research from Edith Cowan University (ECU) has revealed drinking electrolytes instead of pure water can help prevent muscle cramps.

The study, published in the Journal of the International Society of Sports Nutrition, found that people who drank electrolyte enhanced water during and after exercise were less susceptible to muscle cramps than those who drank pure water.

Muscle cramps are a common painful condition affecting many people, including around 39 per cent of marathon runners, 52 per cent of rugby players and 60 per cent of cyclists.

Dilution solution

Lead researcher Professor Ken Nosaka, from ECU's School of Medical and Health Sciences, said the study builds on the evidence that a lack of electrolytes contributes to muscle cramps, not dehydration.

"Many people think dehydration causes muscle cramps and will drink pure water while exercising to prevent cramping," he said.

"We found that people who solely drink plain water before and after exercise could in fact be making them more prone to cramps.

"This is likely because pure water dilutes the electrolyte concentration in our bodies and doesn't replace what is lost during sweating."

When cramp strikes

Professor Nosaka began researching the causes of muscle cramps after regularly suffering from them while playing tennis.

The study involved 10 men who ran on a downhill treadmill in a hot (35ºC) room for 40 to 60 minutes to lose 1.5 to 2 per cent of their body weight through sweat in two conditions.

They drank plain water during and after exercise for one condition and took a water solution containing electrolytes in the other condition.

The participants were given an electrical stimulation on their calves to induce muscle cramp. The lower the frequency of the electrical stimulation required, the more the participant is prone to muscle cramp.

"We found that the electrical frequency required to induce cramp increased when people drank the electrolyte water, but decreased when they consumed plain water," said Professor Nosaka.

"This indicates that muscles become more prone to cramp by drinking plain water, but more immune to muscle cramp by drinking the electrolyte water."

Not all water is equal

Electrolytes are minerals including sodium, potassium, magnesium and chloride. They are essential for muscle health and help the body to absorb water.

Oral rehydration solutions contain electrolytes in specific proportions and can be made with water, salt and sugar. They are commonly found in supermarkets and pharmacies.

Professor Nosaka said electrolytes have many benefits for both athletes and the general population.

"Electrolytes are vital to good health -- they help the body to absorb water more effectively than plain water and replace essential minerals lost through sweat or illness," he said.

"People should consider drinking oral rehydration fluids instead of plain water during moderate to intense exercise, when it's very hot or when you are sick from diarrhoea or vomiting."

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