Culture

Researchers created a new astronomical instrument that has successfully aided in estimating the abundance of metals in the early universe. The WINERED instrument allows for better observations of astronomical bodies like quasars in the early universe, billions of years ago. Researchers hope this deeper level of exploration could help answer questions about the origins not only of metals in the universe but also of the stars themselves.

Iron is one of the most important elements for life as we know it, and for the technology, both primitive and modern, that has shaped human history. But details of the exact origin of iron and other important metals such as magnesium remain elusive. Exploration of this is important in the field of astronomy as it also connected to the origins of the first stars that would have begun to shine several hundred million years after the Big Bang.

Project Research Associate Hiroaki Sameshima from the Institute of Astronomy at the University of Tokyo and his team decided a new instrument was needed to study these matters. Due to limited instrumentation, previous observations to collect data for the study of metals' origins mainly looked at old stars nearby. But this only gave astronomers information about our own unique galaxy. A new instrument with enhanced sensitivity to near-infrared light could push the boundary and open up observations of distant quasars, ferociously energetic ancient galactic cores that emitted light when the universe was only 2.4 billion years old.

"By mounting the WINERED instrument on a large telescope, we can see further back in time as we can observe bodies more distant, or more ancient, than those from previous studies. We can now see details of quasars over 10 billion years old," said Sameshima. "WINERED is a special kind of spectrograph, which can read the chemical signatures present in the light from distant bodies. It revealed to us the fingerprints of iron and magnesium in the light from these quasars, and this allowed us to calculate the abundance of these elements when the universe was much younger than previous studies allowed."

Now that the researchers have established a new method to directly examine the abundance of metals in the early universe, the challenge becomes one of refining the technique and broadening its scope to collect more data. With improved data, astronomers can build on this study and create theories to explain the origins of metals including the iron in your blood.

Research findings by a KAIST team provide insight into the complex mechanism of cellular senescence and present a potential therapeutic strategy for reducing age-related diseases associated with the accumulation of senescent cells.

Simulations that model molecular interactions have identified an enzyme that could be targeted to reverse a natural aging process called cellular senescence. The findings were validated with laboratory experiments on skin cells and skin equivalent tissues, and published in the Proceedings of the National Academy of Sciences (PNAS).

"Our research opens the door for a new generation that perceives aging as a reversible biological phenomenon," says Professor Kwang-Hyun Cho of the Department of Bio and Brain engineering at the Korea Advanced Institute of Science and Technology (KAIST), who led the research with colleagues from KAIST and Amorepacific Corporation in Korea.

Cells respond to a variety of factors, such as oxidative stress, DNA damage, and shortening of the telomeres capping the ends of chromosomes, by entering a stable and persistent exit from the cell cycle. This process, called cellular senescence, is important, as it prevents damaged cells from proliferating and turning into cancer cells. But it is also a natural process that contributes to aging and age-related diseases. Recent research has shown that cellular senescence can be reversed. But the laboratory approaches used thus far also impair tissue regeneration or have the potential to trigger malignant transformations.

Professor Cho and his colleagues used an innovative strategy to identify molecules that could be targeted for reversing cellular senescence. The team pooled together information from the literature and databases about the molecular processes involved in cellular senescence. To this, they added results from their own research on the molecular processes involved in the proliferation, quiescence (a non-dividing cell that can re-enter the cell cycle) and senescence of skin fibroblasts, a cell type well known for repairing wounds. Using algorithms, they developed a model that simulates the interactions between these molecules. Their analyses allowed them to predict which molecules could be targeted to reverse cell senescence.

They then investigated one of the molecules, an enzyme called PDK1, in incubated senescent skin fibroblasts and three-dimensional skin equivalent tissue models. They found that blocking PDK1 led to the inhibition of two downstream signalling molecules, which in turn restored the cells' ability to enter back into the cell cycle. Notably, the cells retained their capacity to regenerate wounded skin without proliferating in a way that could lead to malignant transformation.

The scientists recommend investigations are next done in organs and organisms to determine the full effect of PDK1 inhibition. Since the gene that codes for PDK1 is overexpressed in some cancers, the scientists expect that inhibiting it will have both anti-aging and anti-cancer effects.

Earth just got 7 km/s faster and about 2000 light-years closer to the supermassive black hole in the center of the Milky Way Galaxy. But don't worry, this doesn't mean that our planet is plunging towards the black hole. Instead the changes are results of a better model of the Milky Way Galaxy based on new observation data, including a catalog of objects observed over the course of more than 15 years by the Japanese radio astronomy project VERA.

VERA (VLBI Exploration of Radio Astrometry, by the way "VLBI" stands for Very Long Baseline Interferometry) started in 2000 to map three-dimensional velocity and spatial structures in the Milky Way. VERA uses a technique known as interferometry to combine data from radio telescopes scattered across the Japanese archipelago in order to achieve the same resolution as a 2300 km diameter telescope would have. Measurement accuracy achieved with this resolution, 10 micro-arcseconds, is sharp enough in theory to resolve a United States penny placed on the surface of the Moon.

Because Earth is located inside the Milky Way Galaxy, we can't step back and see what the Galaxy looks like from the outside. Astrometry, accurate measurement of the positions and motions of objects, is a vital tool to understand the overall structure of the Galaxy and our place in it. This year, the First VERA Astrometry Catalog was published containing data for 99 objects.

Based on the VERA Astrometry Catalog and recent observations by other groups, astronomers constructed a position and velocity map. From this map they calculated the center of the Galaxy, the point that everything revolves around. The map suggests that the center of the Galaxy, and the supermassive black hole which resides there, is located 25800 light-years from Earth. This is closer than the official value of 27700 light-years adopted by the International Astronomical Union in 1985. The velocity component of the map indicates that Earth is travelling at 227 km/s as it orbits around the Galactic Center. This is faster than the official value of 220 km/s.

Now VERA hopes to observe more objects, particularly ones close to the central supermassive black hole, to better characterizes the structure and motion of the Galaxy. As part of these efforts VERA will participate in EAVN (East Asian VLBI Network) comprised of radio telescope located in Japan, South Korea, and China. By increasing the number of telescopes and the maximum separation between telescopes, EAVN can achieve even higher accuracy.

Portland State University researchers and their collaborators at the Quinault Indian Nation and Oregon State University found microplastics in Pacific razor clams on Washington's sparsely populated Olympic Coast -- proof, they say, that even in more remote regions, coastal organisms can't escape plastic contamination.

Microplastics are pieces of plastic smaller than 5 millimeters that are either intentionally produced at that size, or break down from synthetic clothing, single-use plastic items, or other products. These particles enter the environment and pervade freshwater and marine environments, soils and even the air we breathe.

Britta Baechler, the study's lead author and a recent graduate of PSU's Earth, Environment and Society doctoral program, analyzed the concentrations of microplastics in razor clams collected from eight beaches along the Washington coast and, after surveying recreational clam harvesters,estimated the annual microplastic exposure of those who eat them.

The Pacific razor clam is one of the most sought-after shellfish in Washington. The state's Department of Fish and Wildlife said that during a recent season, the recreational razor clam fishery saw more than 280,000 digger trips with diggers harvesting 4 million clams for the season. It's also a key first food, cultural resource, and vital source of income for members of the Quinault Indian Nation.

During the study, a total of 799 suspected microplastics were found in the 138 clam samples, 99% of which were microfibers. On average, clams had seven pieces of plastic each.

Clams from Kalaloch Beach, the northernmost site near the mouth of Puget Sound, contained significantly more microplastics than clams from the other seven sites. Though the study did not explore the reasons behind this, Baechler noted that there were no major differences in land cover types between Kalaloch and the other sites, but Kalaloch is the closest in proximity of all sites to the densely populated Seattle metro area.

Baechler's team compared whole clams -- minimally processed as if being consumed by an animal predator -- and cleaned clams -- gutted, cleaned of sand debris and grit, and prepared as if being eaten by a person. They found that in thoroughly cleaned clams, the amount of microplastics was reduced by half.

Baechler said this bodes better for people -- 88% percent of the survey respondents reported cleaning clams before eating them -- than for ocean predators that aren't afforded the luxury of cleaning clams prior to consumption.

Surveys of 107 recreational harvesters determined the average number of razor clams consumed per meal and the number of meals containing clams each year. Combining consumption information with the average number of microplastics per clam, the researchers estimated Olympic Coast razor clam harvester-consumers were exposed to between 60 and 3,070 microplastics per year from razor clams for those who thoroughly cleaned their clams before eating them, or between 120 and 6,020 microplastics a year for those who ate them whole without removing the guts, gills or other organs.

"We don't know the exact human health impacts of microplastics we inevitably ingest through food and beverages," said Baechler, who now works as an ocean plastics researcher at Ocean Conservancy. "Our estimates of microplastic exposure from this single seafood item are, for context, far lower than what we likely take in from inhalation, drinking bottled water and other sources, but no amount of plastic in our marine species or seafood items is desirable."

Baechler and Elise Granek, a professor of environmental science at PSU, said that everyone has a role to play in reducing plastic pollution in the marine environment -- from plastic producers and product designers who can develop effective upstream pollution control solutions to consumers who can make substitutions in their daily lives to reduce their plastic footprints.

"We all have become dependent on plastics for our clothing and packaging, and the more plastic we use, the more likely it's going to end up in our drinking water, our food and our air," Granek said. "All of us have a responsibility to do what we can to limit the amount of plastic that we're using."

Computer simulations explain how electrons with wide-ranging energies rain into Earth's upper and middle atmosphere during a phenomenon known as the pulsating aurora. The findings, published in the journal Geophysical Research Letters, suggest that the higher-energy electrons resulting from this process could cause destruction of the part of the ozone in the mesosphere, about 60 kilometres above Earth's surface. The study was a collaboration between scientists in Japan, including at Nagoya University, and colleagues in the US, including from NASA.

The northern and southern lights that people are typically aware of, called the aurora borealis and australis, look like coloured curtains of reds, greens, and purples spreading across the night skies. But there is another kind of aurora that is less frequently seen. The pulsating aurora looks more like indistinct wisps of cloud strumming across the sky.

Scientists have only recently developed the technologies enabling them to understand how the pulsating aurora forms. Now, an international research team, led by Yoshizumi Miyoshi of Nagoya University's Institute for Space-Earth Environmental Research, has developed a theory to explain the wide-energy electron precipitations of pulsating auroras and conducted computer simulations that validate their theory.

Their findings suggest that both low- and high-energy electrons originate simultaneously from interactions between chorus waves and electrons in the Earth's magnetosphere.

Chorus waves are plasma waves generated near the magnetic equator. Once formed, they travel northwards and southwards, interacting with electrons in Earth's magnetosphere. This interaction energizes the electrons, scattering them down into the upper atmosphere, where they release the light energy that appears as a pulsating aurora.

The electrons that result from these interactions range from lower-energy ones, of only a few hundred kiloelectron volts, to very high-energy ones, of several thousand kiloelectron volts, or 'megaelectron' volts.

Miyoshi and his team suggest that the high-energy electrons of pulsating auroras are 'relativistic' electrons, otherwise known as killer electrons, because of the damage they can cause when they penetrate satellites.

"Our theory indicates that so-called killer electrons that precipitate into the middle atmosphere are associated with the pulsating aurora, and could be involved in ozone destruction," says Miyoshi.

The team next plans to test their theory by studying measurements taken during a space rocket mission called 'loss through auroral microburst pulsations' (LAMP), which is due to launch in December 2021. LAMP is a collaboration between NASA, the Japan Aerospace Exploration Agency (JAXA), Nagoya University, and other institutions. LAMP experiments will be able to observe the killer electrons associated with the pulsating aurora.

Newly published research carried out at the University of Guam has used a critically endangered species to show how trees modify leaf function to best exploit prevailing light conditions. The findings revealed numerous leaf traits that change depending on the light levels during leaf construction.

"The list of ways a leaf can modify its shape and structure is lengthy, and past research has not adequately looked at that entire list," said Benjamin Deloso, lead author of the study.

The results appear in the October issue of the journal Biology (doi:10.3390/biology9100333).

Terrestrial plants are unable to move after they find their permanent home, so they employ methods to maximize their growth potential under prevailing conditions by modifying their structure and behavior. The environmental factor that has been most studied in this line of botany research is the availability of light, as many trees begin their life in deep shade but eventually grow tall to position their leaves in full sun when they are old. These changes in prevailing light require the tree to modify the manner in which their leaves are constructed to capitalize on the light that is available at the time of leaf construction.

"One size does not fit all," Deloso said. "A leaf designed to perform in deep shade would try to use every bit of the limited light energy, but a leaf grown under full sun needs to refrain from being damaged by excessive energy."

The research team used Guam's critically endangered Serianthes nelsonii tree as the model species because of the complexity of its leaf design. This tree's leaf is classified as a bi-pinnate compound leaf, a designation that means a single leaf is comprised of many smaller leaflets that are arranged on linear structures that have a stem-like appearance. The primary outcome of the work was to show that this type of leaf modifies many whole-leaf traits in response to prevailing light conditions. Most literature on this subject has not completely considered many of these whole-leaf traits, and may have under-estimated the diversity of skills that compound leaves can benefit from while achieving the greatest growth potential.

This study provides an example of how plant species that are federally listed as endangered can be exploited for non-destructive research, helping to highlight the value of conserving the world's threatened biodiversity while demonstrating a universal concept.

The study was a continuation of several years of research at the University of Guam designed to understand the ecology of the species. The research program has identified recruitment as the greatest limitation of species survival. Recruitment is what botanists use to describe the transition of seedlings into larger juvenile plants that are better able to remain viable. Considerable seed germination and seedling establishment occur in Guam's habitat, but 100% of the seedlings die. Extreme shade is one of the possible stress factors that generate the seedling mortality. Testing this possibility by providing outplanted seedlings with a greater range of sunlight transmission than the 6% recorded in this study may provide answers to the extreme shade stress hypothesis.

The latest results have augmented the team's earlier research that demonstrated how a specialized leaf gland enables rapid leaflet movement when the light energy is excessive. This skill of being able to change the leaflet's orientation is an instantaneous behavior that mitigates the damage that may result from excessive sunlight exposure.

"Just because the tree can't move itself, that doesn't mean it can't move its leaves to avoid stress," Deloso said.

Serianthes nelsonii was listed on the Endangered Species Act in 1987. A formal plan to recover the species was published in 1994 and called for research to more fully understand the factors that limit success of the species. This latest publication adds to the expanding knowledge that the University of Guam is generating to inform conservation decisions into the future.

A Nagoya University-led research team in Japan has found a new neural pathway that links the circadian clock, stress, and wakefulness in mammals. The team identified a neuron, called the corticotropin-releasing factor (CRF) neuron, that becomes excessively active when the mammal is under stress, which could trigger insomnia and other sleep disorders. Their findings were recently published in the journal Science Advances.

Living organisms exhibit a 24-hour oscillation called the circadian rhythm. In mammals, the central circadian clock, located in the brain's suprachiasmatic nucleus (SCN) neurons, regulates the sleep-wake cycle. However, in the event of life-threatening situations, the circadian rhythm signal is shut off to keep the animal awake so that it can escape from danger even when it would normally be time to sleep. Although the temporary shutoff of the sleep-wake cycle is necessary for survival, excessive or prolonged stress caused by such dangers can trigger insomnia and other sleep disorders.

"It is well-known that the circadian clock and stress have an effect on sleep, but it was unclear which neural pathway is crucial for the circadian regulation of sleep and wakefulness," says Dr. Daisuke Ono of the Research Institute of Environmental Medicine at Nagoya University. To determine the pathway, a Nagoya University research team led by Prof. Akihiro Yamanaka and Dr. Ono, in collaboration with Takashi Sugiyama at Olympus Corporation in Japan, conducted a study using mice.

The researchers focused on CRF neurons -- which are known to play a role in stress response -- that are located in the paraventricular nucleus of the hypothalamus. They investigated how sleep and wakefulness in mice would be affected when the CRF neurons were activated. The results showed that the activated CRF neurons kept the animals awake and made them move around vigorously, indicating that their wakefulness was promoted. The researchers also observed that CRF neurons remained active when the mice were awake, and that when the neurons' activity was suppressed, the animals' wakefulness and locomotor activities were reduced.

Further investigations also showed that inhibitory neurons in the SCN, called GABAergic neurons, play a significant role in regulating the activity of CRF neurons, and that the activation of CRF neurons stimulates orexin neurons in the lateral hypothalamus, which results in the promotion of wakefulness.

The team thus concluded that GABAergic neurons in the SCN control the activity of CRF neurons, which ultimately regulates the sleep-wake cycle. "We identified this neural pathway in mice, which are nocturnal animals. Further studies are required to elucidate how the nocturnal and diurnal difference is regulated in the brain," says Dr. Ono.

"In today's society, sleep disorders are a serious problem. We hope our finding will contribute to the development of new therapies for insomnia and other sleep disorders caused by stress or a disturbed circadian rhythm."

Tsukuba, Japan -- With fall and winter holidays coming up, many will be pondering the relationship between food and sleep. Researchers led by Professor Masashi Yanagisawa at the University of Tsukuba in Japan hope they can focus people on the important middlemen in the equation: bacterial microbes in the gut. Their detailed study in mice revealed the extent to which bacteria can change the environment and contents of the intestines, which ultimately impacts behaviors like sleep.

The experiment itself was fairly simple. The researchers gave a group of mice a powerful cocktail of antibiotics for four weeks, which depleted them of intestinal microorganisms. Then, they compared intestinal contents between these mice and control mice who had the same diet. Digestion breaks food down into bits and pieces called metabolites. The research team found significant differences between metabolites in the microbiota-depleted mice and the control mice. As Professor Yanagisawa explains, "we found more than 200 metabolite differences between mouse groups. About 60 normal metabolites were missing in the microbiota-depleted mice, and the others differed in the amount, some more and some less than in the control mice."

The team next set out to determine what these metabolites normally do. Using metabolome set enrichment analysis, they found that the biological pathways most affected by the antibiotic treatment were those involved in making neurotransmitters, the molecules that cells in the brain use to communicate with each other. For example, the tryptophan-serotonin pathway was almost totally shut down; the microbiota-depleted mice had more tryptophan than controls, but almost zero serotonin. This shows that without important gut microbes, the mice could not make any serotonin from the tryptophan they were eating. The team also found that the mice were deficient in vitamin B6 metabolites, which accelerate production of the neurotransmitters serotonin and dopamine.

The team also analyzed how the mice slept by looking at brain activity in EEGs. They found that compared with the control mice, the microbiota-depleted mice had more REM and non-REM sleep at night--when mice are supposed to be active--and less non-REM sleep during the day--when mice should be mostly sleeping. The number of REM sleep episodes was higher both during the day and at night, whereas the number of non-REM episodes was higher during the day. In other words, the microbiota-depleted mice switched between sleep/wake stages more frequently than the controls.

Professor Yanagisawa speculates that the lack of serotonin was responsible for the sleep abnormalities; however, the exact mechanism still needs to be worked out. "We found that microbe depletion eliminated serotonin in the gut, and we know that serotonin levels in the brain can affect sleep/wake cycles," he says. "Thus, changing which microbes are in the gut by altering diet has the potential to help those who have trouble sleeping."

So, this holiday season, when you're feeling sleepy after eating tryptophan-stuffed turkey, please don't forget to thank your gut microbes!

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.