Culture

Through video tracking and examination of museum specimens, scientists have discovered why Siberia's Lake Baikal seals are thriving when so many other seal populations are suffering from human-caused environmental stresses.

Lake Baikal is the largest and deepest freshwater lake in the world, containing more water than all of North America's Great Lakes combined. Native only to the lake whose name it bears, the Baikal seal is the only exclusively freshwater seal in the world.

Baikal seals are thriving in this location even as populations of many seals elsewhere have been hit by anthropogenic stresses. It appears to quite like chomping on amphipods, extremely tiny crustaceans typically under 10mm long. These are so small that in terms of the energy gained from eating them, it really should not be worth the hassle of hunting them individually. Yet Lake Baikal seals do precisely this, a rare behaviour for seals or toothed whales anywhere else.

It turns out they have highly specialized comb-line teeth that allow them to expel water while retaining prey during high-speed hunting. Their small size, compared to most other seals, also allows them to achieve a net energy gain from these crustaceans that no other aquatic mammals are terribly keen to eat, according to a study published November 16, 2020 in Proceedings of the National Academy of Sciences (PNAS).

While researchers until now had thought Baikal seals primarily stuck to fish, past investigations of stomach contents have shown that Lake Baikal seals also feed on the amphipod Macrohectopus branickii, the world's only freshwater amphipod with a planktonic (floating) lifestyle. But the plankton's tiny size (only a few centimeters long and weighing less than 0.1gram) and the fact that all of its body parts are digestible made it challenging to ascertain just how much plankton these seals ate - and how such tiny prey sustains the seal.

Using animal-borne accelerometers and video cameras, Yuuki Watanabe, a marine biologist with Japan's National Institute of Polar Research, and colleagues recorded Baikal seals' foraging behavior, and found that contrary to the prevailing view that they mainly eat fish, the seals actually hunted the amphipod at extremely high rates.

On average, Baikal seals caught 57 amphipods per dive - not all at once, but hunting them individually, leading to thousands of amphipod catches per day. This represents the highest consumption rate ever recorded of any aquatic mammal that feeds on single prey one at a time rather than scooping up lots of different types of prey all at once. In one case, the research team observed a seal hunting down 154 individual amphipods, meaning that it hunted one every 2.5 seconds.

Everywhere else in the world, amphipods are rarely targeted by aquatic mammals, except for a few baleen whales which are able to do so using baleen, which acts as a great big filter to collect krill, plankton and small fish. But hunting these tiny crustaceans individually would have made gaining an energy surplus almost impossible. Swallowing prey and water together requires extra muscular activity, adding to the energy expenditure, and in turn slowing down foraging rates, further reducing the energy profit.

"Each time the seals open their mouth to try to catch an amphipod, there is this huge drawback," said Watanabe, the paper's first author. "Water is inevitably going to be swallowed too."

To answer this question, the team examined museum specimens of the seal, and found that Baikal seals have the most specialized comb-like post-canine teeth in the subfamily Phocinae (Northern seals). This unique feature allows them to expel water while retaining prey during high-speed foraging.

The small body size of the Baikal seals also plays a role in making individual hunting of tiny amphipods energetically rational. Weighing in at around 50 kilograms, they are some of the smallest seals in the world. The researchers modeled the relationship of predator body size, prey body size, and the number of prey a predator needs to consume per dive to replenish the energy expended during the dive. As predator body mass increases, the number of prey needed to be caught per dive increases rapidly. But the Baikal seal size hits the sweet spot where there is a substantial energy profit.

The final piece of the puzzle of the Baikal seal's unique prey choice, and why it hasn't been threatened by human-caused environmental changes lies in where it lives: Lake Baikal produces very little algae but is abundant in amphipods.

"This apparent paradox can at least partly be resolved by our finding that the seals eat the amphipods instead of just eating the fish that eat the amphipods," said Watanabe.

When an organism from a lower trophic level, or food chain, is consumed by one at a higher level, there is a certain loss of energy. "When the seals eat the prey of the fish directly, they are basically shortcutting this chain, and thus avoiding that energy loss."

The researchers conclude that this evolutionary innovation gives the ecosystem a greater capacity to support apex predators than would otherwise be the case, even given significant levels of human disturbance.

In 2018 an international team of researchers using the NASA/ESA Hubble Space Telescope and several other observatories uncovered, for the first time, a galaxy in our cosmic neighborhood that is missing most of its dark matter. This discovery of the galaxy NGC 1052-DF2 was a surprise to astronomers, as it was understood that dark matter is a key constituent in current models of galaxy formation and evolution. In fact, without the presence of dark matter, the primordial gas would lack enough gravitational pull to start collapsing and forming new galaxies. A year later, another galaxy that misses dark matter was discovered, NGC 1052-DF4, which further triggered intense debates among astronomers about the nature of these objects.

Now, new Hubble data have been used to explain the reason behind the missing dark matter in NGC 1052-DF4, which resides 45 million light-years away. Mireia Montes of the University of New South Wales in Australia led an international team of astronomers to study the galaxy using deep optical imaging. They discovered that the missing dark matter can be explained by the effects of tidal disruption. The gravity forces of the neighboring massive galaxy NGC 1035 are tearing NGC 1052-DF4 apart. During this process, the dark matter is removed, while the stars feel the effects of the interaction with another galaxy at a later stage.

Until now, the removal of dark matter in this way has remained hidden from astronomers as it can only be observed using extremely deep images that can reveal extremely faint features. "We used Hubble in two ways to discover that NGC 1052-DF4 is experiencing an interaction," explained Montes. "This includes studying the galaxy's light and the galaxy's distribution of globular clusters."

Thanks to Hubble's high resolution, the astronomers could identify the galaxy's globular cluster population. The 10.4-meter Gran Telescopio Canarias (GTC) telescope and the IAC80 telescope in the Canary Islands of Spain were also used to complement Hubble's observations by further studying the data.

"It is not enough just to spend a lot of time observing the object, but a careful treatment of the data is vital," explained team member Raúl Infante-Sainz of the Instituto de Astrofísica de Canarias in Spain. "It was therefore important that we use not just one telescope/instrument, but several (both ground- and space-based) to conduct this research. With the high resolution of Hubble, we can identify the globular clusters, and then with GTC photometry we obtain the physical properties."

Globular clusters are thought to form in the episodes of intense star formation that shaped galaxies. Their compact sizes and luminosity make them easily observable, and they are therefore good tracers of the properties of their host galaxy. In this way, by studying and characterizing the spatial distribution of the clusters in NGC 1052-DF4, astronomers can develop insight into the present state of the galaxy itself. The alignment of these clusters suggests they are being "stripped" from their host galaxy, and this supports the conclusion that tidal disruption is occurring.

By studying the galaxy's light, the astronomers also found evidence of tidal tails, which are formed of material moving away from NGC 1052-DF4. This further supports the conclusion that this is a disruption event. Additional analysis concluded that the central parts of the galaxy remain untouched and only about 7% of the stellar mass of the galaxy is hosted in these tidal tails. This means that dark matter, which is less concentrated than stars, was previously and preferentially stripped from the galaxy, and now the outer stellar component is starting to be stripped as well.

"This result is a good indicator that, while the dark matter of the galaxy was evaporated from the system, the stars are only now starting to suffer the disruption mechanism," explained team member Ignacio Trujillo of the Instituto de Astrofísica de Canarias in Spain. "In time, NGC 1052-DF4 will be cannibalized by the large system around NGC 1035, with at least some of their stars floating free in deep space."

The discovery of evidence to support the mechanism of tidal disruption as the explanation for the galaxy's missing dark matter has not only solved an astronomical conundrum, but has also brought a sigh of relief to astronomers. Without it, scientists would be faced with having to revise our understanding of the laws of gravity.

"This discovery reconciles existing knowledge of how galaxies form and evolve with the most favorable cosmological model," added Montes.

Going through a divorce is extremely challenging and previous research has highlighted the adverse effects that it can have on divorcees. A recent study in open-access journal Frontiers in Psychology is the first to examine health impacts immediately after a divorce. The study found that the mental and physical health of recent divorcees was worse than that of the background population and that higher levels of conflict predicted worse mental health, regardless of other factors. Understanding these effects could assist researchers in designing interventions that help divorcees to get back on their feet and avoid long-term repercussions.

Researchers have been examining the mental and physical effects of divorce, but may have missed an opportunity to accurately characterize these effects, until now. Divorce is often a protracted process, with many countries requiring a separation period before couples can apply for divorce. However, a long separation may allow psychological wounds to heal and assessing divorcees after such a period may underestimate their impact.

"Previous studies have not investigated the effects of divorce without extensive separation periods occurring before the divorce," said Prof Gert Hald, of the University of Copenhagen in Denmark. "We were able to study divorcees who had been granted a so-called 'immediate' divorce in Denmark and on average, these divorcees obtained a divorce within 5 days of filing for it."

This allowed Hald and colleagues, including Dr Søren Sander of the University of Copenhagen, to obtain 'real-time' data on 1,856 very recent divorcees, who completed questionnaires about their background, health and their divorce.

Unsurprisingly, the study showed that a recent divorce takes an emotional and physical toll. "The mental and physical health of divorcees was significantly worse than the comparative background population immediately following divorce," said Sander.

However, some interesting trends emerged from the data. For instance, among men, earning more and being younger predicted better physical health, while having more children, having a new partner and even having more previous divorces was associated with better mental health. Among women, earning more money, having a new partner and having fewer previous divorces was associated with better physical health, while initiating the divorce and having a new partner predicted better mental health.

However, one factor had a big influence on the divorcees -- conflict. "Across gender, higher levels of divorce conflict were found to predict worse mental health, even when accounting for other socio-demographic variables and divorce characteristics," said Sander.

So, how can the findings help people to navigate a divorce with their health intact? Targeted interventions early during the process may be key. "We need evidence-based interventions that can help divorcees immediately following divorce," said Hald. "These might include face-to-face or digital interventions that are designed to reduce the specific adverse mental and physical health effects of divorce. Not only would this be beneficial for divorcees, but it could also save money by countering the negative impacts of divorce on work-place productivity, sick days, doctor visits and use of health care facilities."

In another recent study, the researchers developed an online digital solution called 'Cooperation After Divorce' that helps divorcees to significantly reduce such adverse mental and physical health effects. The results of this latest study will help them to refine such approaches in the future.

BUFFALO, N.Y. -- Anyone who has undergone a nasal swab or saliva test for COVID-19 knows that the virus is most easily detected in the nose and mouth. That's why, University at Buffalo researchers argue in a new paper, more COVID-19 studies should be devoted to how immunity emerges to SARS-CoV-2 in the mucous membranes of the nose and mouth.

The paper was published Nov. 30 in Frontiers in Immunology.

Noting that the mucosal immune system is the immune system's largest component, the researchers expressed concern that it hasn't been a focus of much of the research on COVID-19 to date.

"We think it is a serious omission to ignore the mucosal immune response to SARS-CoV-2, given its initial sites of infection," said Michael W. Russell, PhD, emeritus professor, Department of Microbiology and Immunology in the Jacobs School of Medicine and Biomedical Sciences at UB, and senior author on the paper. "Clearly the response of the systemic immunoglobulin G antibody [the most abundant circulating antibody] is important -- we do not deny that -- but on its own it is insufficient."

Russell noted that naturally, the initial focus of research on the disease was on cases of severe disease when the virus descends into the lower respiratory tract, especially the lungs, where the cellular immune responses exacerbate the inflammation rather than fight the infection.

But since the upper respiratory tract, including the nose, tonsils and adenoids are the initial point of infection for the SARS-CoV-2 virus, the immune responses that are triggered there are of special interest.

In addition, the high rate of asymptomatic transmission of COVID-19, which the Centers for Disease Control and Prevention recently estimated at more than 50%, is another reason why mucosal immunity is so important, according to the authors.

'Something, somewhere, does a fairly good job of controlling the virus'

"Given that many infected people remain asymptomatic, and that a large number of those who develop symptoms suffer only mild to moderate disease, this suggests that something, somewhere, does a fairly good job of controlling the virus," said Russell.

"Could it be that this is due to early mucosal immune responses that succeed in containing and eliminating the infection before it becomes serious?" he asked. "We will not know unless these questions are addressed."

The paper recommends that studies are needed to determine the nature of mucosal secretory immunoglobulin A (SIgA) antibody responses over the course of infection, including asymptomatic or pre-symptomatic infection, and mild and moderate cases of COVID-19 disease. In addition, the authors point out that the mucosal immune responses may vary depending on different age groups and populations.

A focus on mucosal immunity might also make it possible to develop a type of vaccine, such as a nasal vaccine, that could be easier to store, transport and administer. Several such vaccines are now under development for COVID-19 but how far along they are is unknown.

Russell added that these vaccines might not have special temperature requirements and might be more palatable for large swaths of the population, especially children, because they would not require an injection.

Potential advantages of a mucosal vaccine

"The potential advantage of a mucosal vaccine - especially one that is intranasal - is that it should induce immune responses, including SIgA antibodies, in the mucosal tracts, in this case especially the upper respiratory tract, where the coronavirus makes first contact," explained Russell, adding that injected vaccines usually do not do this.

Among the areas of study that the authors suggest would be constructive are molecular studies on IgA antibodies and their relationship to the disease stage of COVID-19, and determining the characteristics of cells that secrete IgA antibodies and other mucosal immune cells induced by the infection or by vaccination.

"As mucosal immunologists with several decades of experience behind us, we have been perturbed at the lack of attention to this, and we hope to draw attention to this glaring omission," said Russell. "After all, the mucosal immune system is by far the largest component of the entire immune system, and it has evolved to protect the mucosal surfaces where the great majority of infections arise."

A unique stage of planetary system evolution has been imaged by astronomers, showing fast-moving carbon monoxide gas flowing away from a star system over 400 light years away, a discovery that provides an opportunity to study how our own solar system developed.

Astronomers have detected fast-moving carbon monoxide gas flowing away from a young, low-mass star: a unique stage of planetary system evolution which may provide insight into how our own solar system evolved and suggests that the way systems develop may be more complicated than previously thought.

Although it remains unclear how the gas is being ejected so fast, the team of researchers, led by the University of Cambridge, believe it may be produced from icy comets being vaporised in the star's asteroid belt. The results will be presented at the Five Years After HL Tau virtual conference in December.

The detection was made with the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile, as part of a survey of young 'class III' stars, reported in an earlier paper. Some of these class III stars are surrounded by debris discs, which are believed to be formed by the ongoing collisions of comets, asteroids and other solid objects, known as planetesimals, in the outer reaches of recently formed planetary systems. The leftover dust and debris from these collisions absorbs light from their central stars and re-radiate that energy as a faint glow that can be studied with ALMA.

In the inner regions of planetary systems, the processes of planet formation are expected to result in the loss of all the hottest dust, and class IIII stars are those that are left with - at most - dim, cold dust. These faint belts of cold dust are similar to the known debris discs seen around other stars, similar to the Kuiper belt in our own solar system, which is known to host much larger asteroids and comets.

In the survey, the star in question, 'NO Lup', which is about 70% the mass of our sun, was found to have a faint, low-mass dusty disc, but it was the only class III star where carbon monoxide gas was detected, a first for this type of young star with ALMA. While it is known that many young stars still host the gas-rich planet-forming discs they are born with, NO Lup is more evolved, and might have been expected to have lost this primordial gas after its planets had formed.

While the detection of carbon monoxide gas is rare, what made the observation unique was the scale and speed of the gas, which prompted a follow-up study to explore its motion and origins.

"Just detecting carbon monoxide gas was exciting, since no other young stars of this type had been previously imaged by ALMA," said first author Joshua Lovell, a PhD student from the Cambridge's Institute of Astronomy. "But when we looked closer, we found something even more unusual: given how far away the gas was from the star, it was moving much faster than expected. This had us puzzled for quite some time."

Grant Kennedy, Royal Society University Research Fellow at the University of Warwick, who led the modelling work on the study, came up with a solution to the puzzle. "We found a simple way to explain it: by modelling a gas ring, but giving the gas an extra kick outward," he said. "Other models have been used to explain young discs with similar mechanisms, but this disc is more like a debris disc where we haven't witnessed winds before. Our model showed the gas is entirely consistent with a scenario in which it's being launched out of the system at around 22 kilometres per second, which is much higher than any stable orbital speed."

Further analysis also showed that the gas may be produced during collisions between asteroids, or during periods of sublimation - the transition from a solid to a gaseous phase - on the surface of the star's comets, expected to be rich in carbon monoxide ice.

There has been recent evidence of this same process in our own solar system from NASA's New Horizons mission, when it observed the Kuiper Belt object Ultima Thule in 2019 and found sublimation evolution on the surface of the comet, which happened around 4.5 billion years ago. The same event that vaporised comets in our own solar system billions of years ago may have therefore been captured for the first time over 400 light years away, in a process that may be common around planet-forming stars, and have implications for how all comets, asteroids, and planets evolve.

"This fascinating star is shedding light on what kind of physical processes are shaping planetary systems shortly after they are born, just after they have emerged from being enshrouded by their protoplanetary disk," said co-author Professor Mark Wyatt, also from the Institute of Astronomy. "While we have seen gas produced by planetesimals in older systems, the shear rate at which gas is being produced in this system and its outflowing nature are quite remarkable, and point to a phase of planetary system evolution that we are witnessing here for the first time."

While the puzzle isn't fully solved, and further detailed modelling will be required to understand how the gas is being ejected so quickly, what is sure is that this system is set to be the target of more intense follow-up measurements.

"We're hoping that ALMA will be back online next year, and we'll be making the case to observe this system again in greater detail," said Lovell. "Given how much we have learned about this early stage of planetary system evolution with only a short 30-minute observation, there is still so much more that this system can tell us."

Men with muscles like a young Arnold Schwarzenegger look powerful but a handshake will give away whether they're a healthy specimen - or at risk of a chronic disease or premature ageing, experts say.

Medical researchers in South Australia, led by respiratory and sleep expert Professor Robert Adams, assessed more than 600 men aged over 40 to 88 years in the Men, Androgen, Inflammation, Lifestyle, Environment, and Stress (MAILES) study to measure the link between sleep apnea and muscle mass with grip strength.

Chief investigator of the study, Flinders University Professor Adams, says no matter how much muscle mass, a simple grip test can highlight underlying issues connected with ageing, systemic inflammation and worsening hypoxemia (lack of oxygen in the blood).

"Without good levels of oxygen in the blood, we cannot use the muscles we have to their maximum," says Professor Adams.

"Our findings suggest impairments in hand grip strength (HGS) may be related to fat infiltration of muscle, hypoxemia-induced reductions in peripheral neural innervation, or even endothelial dysfunction - a risk in chronic inflammation and even cancer," Professor Adams and colleagues conclude in a paper in open access journal Nature and Science of Sleep.

"Further studies are required to connect the common sleep problem obstructive sleep apnoea (OSA) with hypoxemia."

OSA is a common problem which involves repeated episodes of partial or complete obstruction of the throat during sleep which can cause breathing to slow down or stop leading to a fall in blood oxygen levels fall as a result.

Lead author of the paper, Adelaide Sleep Institute for Sleep Health researcher Dr David Stevens, says overnight sleep studies of men aimed to link OSA sleep patterns with muscle and fat mass, and in turn grip strength.

"After allowing for health and lifestyle (exercise, smoking and underlying health conditions), it was clear that worsening hypoxemia, which included how much time was spent below 90% oxygen saturation (usually 97%) - and even how long people spent with their airways completely closed (known as apnea) - was associated with reduced grip strength - regardless of muscle mass," Dr Steven says.

"This is important as up until now, age related declines in strength and immobility (sarcopenia) were thought to be due to reductions in muscle which started when someone was over 60 years old. Instead, the declines in strength appear to begin at a younger age in people with obstructive sleep apnea (OSA)," he says.

"Furthermore, considering that over a quarter of the MAILES participants have moderate to severe OSA, this suggests a large proportion of the population are at risk of early reductions in strength".

Further studies of followup sleep studies will test for potential mechanisms to explain the results of the study, Dr Stevens says.

"We recommend that more research be done to further explore the relationship between OSA, body composition, and HGS."

An urgent rethink of infection control policies to keep COVID-19 infection at bay in schools is needed if primary schools are to be kept open this winter, and the knock-on effects on their families avoided, argue children's infectious disease specialists in a viewpoint, published online in the Archives of Disease in Childhood.

The blanket policy currently deployed for children of all ages is not evidence based and is too restrictive and inflexible, significantly disadvantaging primary school children and their families, they say.

The impact of missed schooling on children's physical and mental health and educational development during the first wave of the pandemic far outweighed the benefits of shutting schools in a bid to curb the spread of SARS-CoV-2, the virus responsible for COVID-19 they say. And keen to avoid further school closures during the second wave, governments across Europe have imposed various measures to limit the spread of infection.

These include guidance on the use of face coverings at school, the isolation of children with symptoms and members of their families, as well as isolation of close contacts of confirmed cases.

But, crucially, these recommendations don't seem to be based on evidence, because they vary considerably across Europe, with no distinctions made between primary and secondary school children despite the known differences in the risks of infection and spread in these two age groups, point out the authors.

And there's no provision to tighten or relax restrictions, according to prevailing infection rates. All this disadvantages primary school children, they insist.

That's because young children get between 4 and 8 respiratory infections every winter and the symptoms of a bad cold or other viral infection often overlap with those of COVID-19. And if it's difficult to get a test or takes a while to get a result, young children will inevitably miss significant quantities of schooling this winter, they point out.

And the recommendation in some countries for the entire family of a child with symptoms to isolate while awaiting their test results limits parents' ability to work and siblings' freedom to attend school.

A more pragmatic, evidence-based approach to primary schools, which recognises the unintended consequences of excessively risk averse approaches is needed, write the authors. "The default position for primary schools should be the implementation of less restrictive infection control requirements," they say. This means:

No compulsory face coverings for young children

No requirement for entire bubbles to isolate following a single case at school

No requirement for the entire family to isolate while awaiting the child's test results

Schools prioritised for rapid spit tests for COVID-19 when these become available

Flexibility to tighten or relax restrictions according to local infection rates

Teachers prioritised over children for COVID-19 jab

Lower testing threshold for children with symptoms and vulnerable close relatives

Prioritisation of these children for vaccination

"Implementation of evidence-based recommendations for primary school is a priority for all governments to avoid young children unnecessarily missing significant quantities of schooling this winter, along with a knock-on effect on their families," they conclude.

When the famous Spanish physician Santiago Ramón y Cajal looked through his microscope in 1910, he discovered irregular and "transparent lumps" that appeared throughout the nucleus of a neuron. What these nuclear speckles are all about is still largely unclear, even though the biological and medical sciences have experienced several revolutions since then. "Even though we know quite a bit about their function, we didn't know how nuclear speckles originate, i.e. what their core consists of," says Tuçe Akta from the Max Planck Institute for Molecular Genetics.

A Berlin team of scientists led by the Max Planck Research Group leader now identified the molecules that form the scaffold of nuclear speckles.The two proteins in question are SON and SRRM2, which are present in different variations throughout the entire animal kingdom. Both molecules are involved in the processing of RNA, which is produced when genes are transcribed. Without these proteins, the speckles dissolve.

Unlike other cell structures, speckles do not have a membrane envelope. They consist of an aggregation of molecules that can dynamically dissolve and reassemble, exhibiting the properties of solids as well as those of liquids. These "condensates" can be found throughout the cell. "Each cellular condensate has a protein that represents its nucleus - in the case of nuclear speckles, there are two," says Akta.

Of red herrings and finding the right path

It is no coincidence that past attempts to identify the lowest common denominator of the mysterious structures have not been successful. "For 30 years scientists have been staining nuclear speckles with a reagent that they did not know very well", says Akta. "We did not realize that we have been in the dark for decades."

Since the early nineties, nuclear speckles have been visualised with a substance called SC35, which is an antibody that specifically attaches to certain sites in the speckles and can stain them with the help of pigments. Until recently, however, it was assumed that the antibody only recognizes the small protein SRSF2 - an assumption that now turned out to be wrong. "We wanted to use the antibody as a bait to fish for speckles in the cell," says brahim Avar Ilk, the lead author of the study. "It was a great surprise to find the protein SRRM2, which was not the intended prey for our experiment." It turned out that the antibody not only adheres to the already known SRSF2, but especially and particularly well to SRRM2.

Quest in the evolutionary family tree

While the sequence of SRRM2 varies widely in different animal species, the protein has a small section that has been preserved over hundreds of millions of years of evolution. Looking for similar proteins in the evolutionary family tree, the researchers also noticed the protein SON, which was considered by other research groups as a possible critical component of the speckles, too. "We had the idea that the combination of the two proteins could be the fundamental building block of the speckles", says Ilk.

To test their hypothesis, the team grew human cells with the genes for either SRRM2 or SON switched off. This resulted in only spherical remnants of the speckles in the cell's nuclei. Once the researchers knocked down both proteins simultaneously, all the speckles dissolved completely and associated proteins were found to be distributed throughout the cell nucleus. "We concluded that SRRM2 and SON must be the scaffold for nuclear speckles," says Ilk. "Next, we will investigate how the two proteins bind to other molecules and how this process is controlled".

Historical misinterpretation has consequences

But the results have even more, and perhaps far-reaching consequences. "Now that it is clear that SC35 binds to a different protein than assumed, previous research results on nuclear speckles must be carefully reevaluated," says Akta.

The antibody SC35 has also been widely used in disease research, since the speckles have been implicated in several neurodegenerative conditions such as Huntington's disease, spinocerebellar ataxia and dentatorubro-pallidoluysis atrophy. "There may be entirely new perspectives for research into these diseases," says Akta.

DURHAM, N.C. - The proliferation of pits and ponds created in recent years by miners digging for small deposits of alluvial gold in Peru's Amazon has dramatically altered the landscape and increased the risk of mercury exposure for indigenous communities and wildlife, a new study shows.

"In heavily mined watersheds, there's been a 670% increase in the extent of ponds across the landscape since 1985. These ponds are almost entirely artificial lakes created as thousands of former mining pits fill in with rainwater and groundwater over time," said Simon Topp, a doctoral student in geological sciences at the University of North Carolina at Chapel Hill, who co-led the study.

Landscapes formerly dominated by forests are now increasingly dotted by these small lakes, which, the study finds, provide low-oxygen conditions in which submerged mercury - a toxic leftover from the gold mining process - can be converted by microbial activity into an even more toxic form of the element, called methylmercury, at net rates 5-to-7 times greater than in rivers.

"Methylmercury poses especially high risks for humans and large predators because it bioaccumulates in body tissue as it moves up the food chain. That's particularly concerning given the high biodiversity and the large number of indigenous populations that live in the Peruvian Amazon," said Jacqueline Gerson, a doctoral student in ecology at Duke University, who also co-led the study.

These heightened risks likely also occur in other locations where unregulated artisanal small-scale gold mining takes place, including Asia, sub-Saharan Africa and other parts of South America, she said.

Topp, Gerson and their colleagues published their peer-reviewed study Nov. 27 in Science Advances.

Artisanal gold miners use mercury, a potent neurotoxin, to separate their gold ore from soil and sediments, often without adequate safety precautions to protect themselves or the environment.

Mercury poisoning can cause a wide range of health impacts, including tremors, muscle weakness, vision and hearing impairments, and loss of coordination and balance. In severe cases, it can lead to birth defects or death.

Some of the mercury used by the miners is burned off into the air or spilled into nearby rivers, creating far-reaching environmental and human health risks that have been well documented in past studies. The new study is the first to document how the mining has altered the landscape and simultaneously amplified the risks of mercury poisoning through the creation of ponds and the microbial processing of mercury into methylmercury that occurs there.

To conduct the study, the scientists collected water and sediment samples at sites upstream and downstream of artisanal gold mining sites along Peru's Madre de Dios River, its tributaries, surrounding lakes, and mining ponds during the dry season in July and August of 2019. They measured each sample for total mercury content and for the proportion of that mercury that was in the more toxic form of methylmercury.

By combining these measurements with more than three decades of high-resolution satellite data from the region, they were able to determine the extent of artificial ponding and mercury contamination at each site and identify causal links.

"You can clearly see that the increase in artificial lakes and ponds in heavily mined areas accelerated after 2008, when gold prices dramatically increased along with mining activity," Topp said. By contrast, the total surface area of ponds in areas without heavy mining increased by an average of only 20% over the entire study period.

"We expect that this trend, and the environmental and human health risks it causes, will continue as long as gold prices remain high and artisanal small-scale gold mining is a profitable activity," he said.

We’ve all been there. Whether we’re waiting for a bus that is stuck in traffic, or eagerly anticipating the release of a new book, film or album, there are times when we need to be patient. Learning to suppress the impulse for instant gratification is often vital for future success, but how patience is regulated in the brain remains poorly understood.

Now, in a study on mice conducted by the Neural Computation Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), the co-authors, Dr. Katsuhiko Miyazaki and Dr. Kayoko Miyazaki, pinpoint specific areas of the brain that individually promote patience through the action of serotonin. Their findings were published 27th November in Science Advances.

“Serotonin is one of the most famous neuromodulators of behavior, helping to regulate mood, sleep-wake cycles and appetite,” said Dr. Katsuhiko Miyazaki. “Our research shows that release of this chemical messenger also plays a crucial role in promoting patience, increasing the time that mice are willing to wait for a food reward.”

Their most recent work draws heavily on previous research, where the unit used a powerful technique called optogenetics – using light to stimulate specific neurons in the brain – to establish a causal link between serotonin and patience.

The scientists bred genetically engineered mice which had serotonin-releasing neurons that expressed a light-sensitive protein. This meant that the researchers could stimulate these neurons to release serotonin at precise times by shining light, using an optical fiber implanted in the brain.

The researchers found that stimulating these neurons while the mice were waiting for food increased their waiting time, with the maximum effect seen when the probability of receiving a reward was high but when the timing of the reward was uncertain.

“In other words, for the serotonin to promote patience, the mice had to be confident that a reward would come but uncertain about when it would arrive,” said Dr. Miyazaki.

In the previous study, the scientists focused on an area of the brain called the dorsal raphe nucleus – the central hub of serotonin-releasing neurons. Neurons from the dorsal raphe nucleus reach out into other areas of the forebrain and in their most recent study, the scientists explored specifically which of these other brain areas contributed to regulating patience.

The team focused on three brain areas that had been shown to increase impulsive behaviors when they were damaged – a deep brain structure called the nucleus accumbens, and two parts of the frontal lobe called the orbitofrontal cortex and the medial prefrontal cortex.

“Impulse behaviors are intrinsically linked to patience – the more impulsive an individual is, the less patient – so these brain areas were prime candidates,” explained Dr. Miyazaki.

Good things come to those who wait (or not...)

In the study, the scientists implanted optical fibers into the dorsal raphe nucleus and also one of either the nucleus accumbens, the orbitofrontal cortex, or the medial prefrontal cortex.

The researchers trained mice to perform a waiting task where the mice held with their nose inside a hole, called a “nose poke”, until a food pellet was delivered. The scientists rewarded the mice in 75% of trials. In some test conditions, the timing of the reward was fixed at six or ten seconds after the mice started the nose poke and in other test conditions, the timing of the reward varied.

In the remaining 25% of trials, called the omission trials, the scientists did not provide a food reward to the mice. They measured how long the mice continued performing the nose poke during omission trials – in other words, how patient they were – when serotonin-releasing neurons were and were not stimulated.

When the researchers stimulated serotonin-releasing neural fibers that reached into the nucleus accumbens, they found no increase in waiting time, suggesting that serotonin in this area of the brain has no role in regulating patience.

But when the scientists stimulated serotonin release in the orbitofrontal cortex and the medial prefrontal cortex while the mice were holding the nose poke, they found the mice waited longer, with a few crucial differences.

In the orbitofrontal cortex, release of serotonin promoted patience as effectively as serotonin activation in the dorsal raphe nucleus; both when reward timing was fixed and when reward timing was uncertain, with stronger effects in the latter.

But in the medial prefrontal cortex, the scientists only saw an increase in patience when the timing of the reward was varied, with no effect observed when the timing was fixed.

“The differences seen in how each area of the brain responded to serotonin suggests that each brain area contributes to the overall waiting behavior of the mice in separate ways,” said Dr. Miyazaki.

Modelling patience

To investigate this further, the scientists constructed a computational model to explain the waiting behavior of the mice.

The model assumes that the mice have a predictive model of the timing of reward delivery and estimate the probability that a reward will be delivered. While they keep waiting without receiving a food pellet, the estimated probability for the trial to be a reward trial gradually goes down, and the mice accordingly decide whether or not to keep waiting. The model also assumes that the orbitofrontal cortex and the medial prefrontal cortex use different predictive models of reward timing to calculate reward probabilities individually, with the latter being more sensitive to variations in timing.

The researchers found that the model best fitted the experimental data of waiting time by increasing the initially expected reward probability from 75% to 94% under serotonin stimulation. Put more simply, serotonin increased the mice’s belief that they were in a reward trial, and so they waited longer.

Importantly, the model assumed that stimulation of the orbital frontal cortex and the medial prefrontal cortex separately increased the initial reward probability from 75% to 94% only in that particular area, whereas stimulation of the dorsal raphe nucleus increased the probability in both areas. Only under these assumptions was the model able to successfully reproduce all the behavioral data.

“This confirmed the idea that these two brain areas are calculating the probability of a reward independently from each other, and that these independent calculations are then combined to ultimately determine how long the mice will wait,” explained Dr. Miyazaki. “This sort of complementary system allows animals to behave more flexibly to changing environments.”

Ultimately, increasing our knowledge of how different areas of the brain are more or less affected by serotonin could have vital implications in future development of drugs. For example, selective serotonin reuptake inhibitors (SSRIs) are drugs that boost levels of serotonin in the brain and are used to treat depression.

“This is an area we are keen to explore in the future, by using depression models of mice,” said Dr. Miyazaki. “We may find under certain genetic or environmental conditions that some of these identified brain areas have altered functions. By pinning down these regions, this could open avenues to provide more targeted treatments that act on specific areas of the brain, rather than the whole brain.”

Does poverty cause lying? An international research team led by behavioral economist Agne Kajackaite from the WZB Berlin Social Science Center, Suparee Boonmanunt (Mahidol University, Bangkok) and Stephan Meier (Columbia Business School) examined whether poverty-stricken individuals were especially prone to acts of dishonesty. The researchers ran a field experiment with rice farmers in Thailand which incentivized cheating during a card game. They found that poverty itself did not cause individuals to act dishonestly.

Whether income influences ethical behavior is a topic of much debate. One approach holds that ethical acts are limited to those who can 'afford' them. Poverty, in this view, causes individuals to behave immorally. Empirically, the question whether poverty fosters or dampens prosocial behavior, has thus far remained unanswered.

The research team is now shedding new light on this relation. To provide a causal link between poverty and cheating behavior, the researchers conducted a field experiment with several hundred rice farmers in Thailand. The experiment consisted of a simple card game that rewarded individuals financially for lying about a card they had drawn blindly from a stack. The researchers found that participants cheated to a similar extent both during periods of relative poverty and relative wealth, that is, before and after harvesting season. "Contrary to the standard economic model - where no cash leads to cheating for cash - we show that poverty itself does not lead persons to behave more immorally", says Agne Kajackaite, head of the research group Ethics and Behavioral Economics at the WZB Berlin Social Science Center.

The study also provides evidence for the effectiveness of social interventions. Briefing subjects on the ethical implications of cheating changed the participants' behavior when the population was somewhat richer (after harvest), but had no effect when the population was poorer (before harvest). "This suggests that the timing of interventions to improve people's behavior matters", Kajackaite explains the study's policy implication.

LAWRENCE -- Researchers from the University of Kansas have described a galaxy more than 5.25 billion light years away undergoing a rarely seen stage in its galactic life cycle. Their findings recently were published in the Astrophysical Journal.

The galaxy, dubbed CQ 4479, shows characteristics that normally don't coexist: an X-ray luminous active galactic nuclei (AGN) and a cold gas supply fueling high star formation rates.

"Massive galaxies, such as our own Milky Way, host a supermassive black hole at their hearts -- these are black holes that grow by accreting interstellar gas onto themselves to become more massive," said Kevin Cooke, lead author and postdoctoral researcher in KU's Department of Physics & Astronomy. "The end of galactic growth is thought to happen when this gas accretion onto the black hole occurs in sufficient quantities that it produces a tremendous amount of energy. Then, all of that energy surrounding the black hole will actually heat up the rest of the gas throughout the galaxy in such a way that it can't condense any more to form stars and the galaxy's growth stops."

The KU researchers instead found CQ 4479, a galaxy which never had been closely studied before, to be still generating new stars in spite of the luminous AGN at the galaxy's center.

"Normally, we expect that to shut everything else off," Cooke said. "But instead, we see massive amounts of new stars being formed in this galaxy. So, it's a very limited time window where you can see both the black hole growing and the stars surrounding it growing at the same time."

The researchers observed the cold quasar primarily using NASA's SOFIA infrared telescope, which is flown aboard a Boeing 747 aircraft. Other measurements were made using FUV-FIR photometry and optical spectroscopy. The work was supported by a NASA grant to primary investigator Allison Kirkpatrick, assistant professor of physics & astronomy at KU, who co-wrote the new paper.

Kirkpatrick said the team's various methods of observing the galaxy showed contradictory data, making the nature of CQ 4479 even more of a puzzle.

"What's really unique about this source is we have different measurements of the energy output near the black hole," Kirkpatrick said. "That tells you how fast the black hole is growing and also its feedback into the host galaxy that can shut down star formation. We have everything from X-ray, to optical and the infrared, so we're able to measure several different signatures of the black hole's energy output. And the signatures don't agree -- that's really rare. One interpretation is the growth of the black hole is slowing, because the X-rays come from right next to the black hole, while the optical signatures come from a little bit further out, and the infrared signatures come from further out as well. Essentially, less energy seems to be being produced right around the black hole now than it was in the past."

The researchers seem to be looking at a snapshot of the galaxy during a pivotal stage of its lifespan.

"I think this is a galaxy undergoing a midlife crisis," Kirkpatrick said. "It's going through one last burst of star formation. Most of its solar mass is already in place. It's forming a few more stars now, and the thing that's ultimately going to kill it is starting to kick in."

In part, the research at KU was performed by Kirkpatrick's undergraduate student and co-author Michael Estrada, now a graduate student at University of Florida.

"He did the data analysis of the optical spectroscopy and measured the black hole mass for us," Kirkpatrick said.

Other questions about the physical structure of the galaxy remain because current instrumentation available to astronomers don't provide clear enough images of CQ 4479.

"The image we have shows a central blob and then a little smaller blob below it," Kirkpatrick said. "So we don't have a good sense for how this galaxy looks because the central AGN is so bright that it out shines the rest of the host galaxy. This is a real problem that plagues all AGN studies -- when you're dealing with the most luminous things they tend to outshine your host at nearly every wavelength."

The researchers said CQ 4479 would require more study, particularly using the ALMA Observatory and the NASA's James Webb Space Telescope -- the most powerful space telescope ever designed and currently slated for launch Oct. 31, 2021. Both Cooke and Kirkpatrick hope to perform more investigations of the strange cold quasar once the telescope is launched.

"We're currently banking on James Webb, because it will have excellent resolution and we should be able to look at wavelengths where we can see the shape of the galaxy," Kirkpatrick said. "Another good option would be ALMA. But ALMA has unfortunately shut down temporarily because of COVID. We've kind of been stymied at seeing the host galaxy."

The importance of understanding the strange processes underway in a galaxy 5.25 billion light years from Earth might seem vague at first, but Cooke said a better understanding of the cold quasar could improve understanding of the cosmos and the fate of our own galaxy.

"This very much ties into asking 'where do we come from?' and 'what processes were involved in the creation of galaxies?,' and that's important because we live in a galaxy," Cooke said. "We live in one of these vast collections of billions of stars and knowing the processes of what created our home is valuable information. Trying to understand big ticket questions like these also spur important engineering developments here on Earth, such as the detector technology and all the fancy engineering that goes into the SOFIA telescope -- there are plenty of ways how this type of work it benefits us here on Earth."

In new research presented at Euroanaesthesia (the annual meeting of the European Society of Anaesthesiology and Intensive Care [ESAIC]), doctors report a highly unusual case of a right-handed patient performing unconscious 'mirror-writing' with her left hand while in the midst of having epileptic seizures in the emergency room. The study is by Dr Laura Freitas and Dr Sofia R. de Valdoleiros, Centro Hospitalar Universitário do Porto, Portugal, and colleagues.

Mirror writing is writing which runs in the opposite direction to normal, with individual letters also reversed, nearly always undertaken with the left hand. It can be seen in healthy individuals or associated with various focal lesions that most commonly involve the left hemisphere. However, it has not yet been described in people with epilepsy.

This new case involved a 42-year-old right-handed female patient, with a form of epilepsy called non-lesional left frontal epilepsy diagnosed at age 18 years. She was being treated with various medications and had needed previous hospitalisations due to seizures requiring coma induction.

On this occasion, she presented to the emergency room of Centro Hospitalar Universitário do Porto with another episode of focal seizures involving her right arm. Infectious and metabolic causes were excluded, and despite the administration of diazepam 40mg IV and levetiracetam 1500mg IV to help sedate her, the seizures continued.

Between seizures, the patient presented with an episode of mirror writing (see link to image below) with her left hand. The writing said (in Portuguese) '"My head can't take it anymore I need You to stop my head it doesn't stop". General anaesthesia and deep sedation were required to bring the seizures under control.

The patient's relatives, who accompanied her to the hospital, said that she had performed mirror writing after previous seizures. When she regained consciousness, the woman had no memory of the mirror writing, and is unable to repeat it when not having seizures.

The authors say: "Unaware mirror writing with the left hand was present in this right-handed patient with epilepsy affecting the right upper limb. Stroke patients with right-sided partial paralysis can rarely present with spontaneous mirror writing, using the left hand. We hypothesise that our patient, while feeling impaired to write normally with her right hand during seizures, attempts to do so with her left hand, and mirror writing occurs."

They add: "To the best of our knowledge, this is the first case of mirror writing reported in a patient with epilepsy. Physicians should be aware of this condition, which may be underreported."

People borrowing money for the first time should only be given small amounts until they have proved their competence, a new study says.

The paper argues that new borrowers - especially young people and those of an "impulsive" disposition - need protection to prevent them falling into long-term debt.

It says lenders should have a duty of care, requiring them to consider age, experience and personality traits, which can be detected by psychometric tests.

The study, by Professor Stephen Lea of the University of Exeter, reviews evidence on the psychology of debt, and makes recommendations to help reduce debt problems.

"I argue that - similar to obtaining a driving licence - people should have to demonstrate their competence before taking out debts that could have long-term negative consequences," Professor Lea said.

"Some people are particularly susceptible to debt problems.

"This includes those of an impulsive disposition, but it particularly applies to young people - and debts contracted early in life can have long-term ill effects.

"Accordingly, steps need to be taken to protect people at this vulnerable life stage.

"Although this would involve a restriction of the financial freedom of people who are legally adults, the evidence suggests that access to credit should be controlled more carefully."

Speaking about rules relating to people of an "impulsive" disposition, Professor Lea said: "Lenders might well resist such regulations, but in fact financial advisors are already required to assess risk preference when advising people on investments.

"This shows that such a measure can be brought in without too much difficulty or expense to those who have to implement it."

Professor Lea acknowledges that debt is heavily influenced by economic inequality, and that no psychological factor can prevent debt if excessive socio-economic disadvantage is not addressed.

He also says the current Covid-19 pandemic is likely to increase debt problems.

His recommendations include tackling poverty (reducing the "decades-long drift towards greater inequality in almost all countries") and intensifying regulation of high-cost lenders.

Recommending better financial education of children, Professor Lea said: "Many people are shockingly bad at assessing credit deals.

"What seems to be needed is fluency in seeing, without effortful calculation, what is or is not a good deal when borrowing money."

The paper calls for policies to improve people's awareness of their credit position, and says debtors should be advised to seek independent advice before dealing with lenders to whom they owe money.

He concludes: "If all these recommendations were adopted overnight, the problems of debt in society would not go away.

"Credit enhances consumer choice and is a necessary function in a modern economy, and so long is credit is available, some people will get into difficulties with debt.

"But, as is the case with poverty itself, neither the extent nor the level of debt is fixed.

"Appropriate policies, such as those proposed here, could reduce both."

Decreases in hospital attendances and admissions amid fears of COVID-19 may result in avoidable harm for under 16s say researchers, who warn against the "unintended consequences of pandemic control measures".

Research led by Dr Rachel Isba from Lancaster University, Dr Rachel Jenner from Royal Manchester Children's Hospital, and Dr Marc Auerbach from Yale University analysed attendances and admissions to Paediatric Emergency Departments (PED) at the Royal Manchester Children's Hospital in the UK and Yale New Haven Children's Hospital in the US.

The Royal Manchester Children's Hospital, part of Manchester University NHS Foundation Trust is the largest and busiest children's hospital in the UK and the PED sees approximately 50,000 patients per year. The PED at Yale New Haven Children's Hospital sees over 38,000 patients per year. Both hospitals are in geographical areas that went into "lockdown" on March 23, 2020.

The international team compared the differences between weekly attendances and admissions (via the PED) from January 1, 2020, to May 20, 2020 compared with the same period in 2019.

Following lockdown, they found "a striking decrease" in the number of children and young people attending the PED at both hospitals.

Despite this, after lockdown they were up to 60% more likely to be admitted to hospital in 2020 compared to the same period in 2019, suggesting they may have been more unwell by the time they attended hospital.

The researchers said: "These observations likely reflect both a genuine decrease in need (eg, fewer viral infections) but also an increase in delayed and unmet need. Children and adolescents presenting later on in their illness are more likely to have a negative outcome."

"Although the direct effects of COVID-19 currently appear to be less severe in children and adolescents, only time will reveal the indirect negative impacts on this age group, including deaths, because of delayed Paediatric Emergency Department presentation."

They said that fear of COVID-19 was likely to have been a factor in the reduced numbers of under 16s attending hospital PEDs.

"Although not explored here, contributing factors are likely to include the parent or caregiver's fear of the virus, resulting in higher personal thresholds for needing to attend, and will need to be addressed proactively in case of future lockdowns.

"Those with responsibility for making and communicating decisions around lockdown need to be aware of the unintended consequences of pandemic control measures. As a minimum, there needs to be clear and consistent messaging around when it is appropriate to take an ill or injured child to hospital--emphasising that a PED visit can be made safely-- delivered at the start of any future periods of lockdown."