Study finds that sleep restriction amplifies anger

 Feeling angry these days? New research suggests that a good night of sleep may be just what you need.

This program of research comprised an analysis of diaries and lab experiments. The researchers analyzed daily diary entries from 202 college students, who tracked their sleep, daily stressors, and anger over one month. Preliminary results show that individuals reported experiencing more anger on days following less sleep than usual for them.

The research team also conducted a lab experiment involving 147 community residents. Participants were randomly assigned either to maintain their regular sleep schedule or to restrict their sleep at home by about five hours across two nights. Following this manipulation, anger was assessed during exposure to irritating noise.

The experiment found that well-slept individuals adapted to noise and reported less anger after two days. In contrast, sleep-restricted individuals exhibited higher and increased anger in response to aversive noise, suggesting that losing sleep undermined emotional adaptation to frustrating circumstance. Subjective sleepiness accounted for most of the experimental effect of sleep loss on anger. A related experiment in which individuals reported anger following an online competitive game found similar results.

"The results are important because they provide strong causal evidence that sleep restriction increases anger and increases frustration over time," said Zlatan Krizan, who has a doctorate in personality and social psychology and is a professor of psychology at Iowa State University in Ames, Iowa. "Moreover, the results from the daily diary study suggest such effects translate to everyday life, as young adults reported more anger in the afternoon on days they slept less."

The authors noted that the findings highlight the importance of considering specific emotional reactions such as anger and their regulation in the context of sleep disruption.

From Science Daily

Genetics of the tree of life

 The African baobab tree (Adansonia digitata) is called the tree of life. Baobab trees can live for more than a thousand years and provide food, livestock fodder, medicinal compounds, and raw materials. Baobab trees are incredibly significant. However, there are growing conservation concerns and until now, a lack of genetic information.

The African baobab tree has 168 chromosomes -- critical knowledge for further genetic studies, conservation, and improvement for agricultural purposes. The findings were published in the journal Scientific Reports. Previous studies estimated that the tree has between 96 and 166 chromosomes.

"We were able to unequivocally count the chromosomes," says Nurul Faridi, a USDA Forest Service research geneticist who co-led the study with Hamidou Sakhanokho, a USDA Agricultural Research Service research geneticist.

The researchers used fluorescent probes to see the genetic components of individual chromosomes within the cells -- which glow like jewels.

The analysis also revealed that the tree has a massive nucleolus organizer region (NOR). Relative to the main chromosome body, this region appears larger than that of any other plant species. During certain stages of the cell cycle, nucleoli form at the NORs. The nucleoli are essential for ribosome assembly and protein synthesis in eukaryotes and are an important feature that differentiates eukaryotes from prokaryotes.

"These genetic findings are foundational and will make genetic conservation of the African baobab tree more efficient and effective," says Dana Nelson, a coauthor and project leader of the Southern Research Station's genetic unit. "This research is also a precursor for tree breeding programs seeking to improve baobab for silvicultural applications."

From Science Daily

Using the past to maintain future biodiversity

 New research shows that safeguarding species and ecosystems and the benefits they provide for society against future climatic change requires effective solutions which can only be formulated from reliable forecasts.

An international team of scientists led by researchers from the University of Adelaide and University of Copenhagen, has identified and examined past warming events similar to those anticipated in the coming decades, to better understand how species and ecosystems will cope.

"Reference periods in Earth's history serve as natural laboratories for understanding biodiversity responses to climate change and improving strategies for conservation under ongoing and future climate change," says lead author Associate Professor Damien Fordham from the University of Adelaide's Environment Institute.

Approximately 40 per cent of terrestrial ecosystems are projected to have experienced shifts in temperature during the past 21,000 years that are similar in pace and magnitude to regional-scale future forecasts.

"Studying locations in regions such as the Arctic, Eurasia, the Amazon and New Zealand can inform numerous international conservation plans for species and ecosystems around the world," says Associate Professor Fordham.

"Using fossil and molecular data from these areas, together with advanced computational approaches, we have identified biological responses to potentially dangerous rates of climatic change."

"This new knowledge from the past tells us that terrestrial biodiversity will experience significant changes in response to future global warming. These include wide-scale species declines, threatening the goods and services ecosystems provide to humanity."

Associate Professor David Nogues-Bravo from the University of Copenhagen was co-author of the study which is published in the journal Science.

"Beyond intrinsic knowledge gain, this integrative research is providing relevant context and case studies that can minimize biodiversity loss from climate change," he says.

"This includes identifying what causes some species to be more prone to climate-driven extinction than others, and how to improve early-warning systems signalling population collapse, extinction or ecosystem shifts as a result of climate change."

The team emphasises that integrating knowledge of biodiversity responses to past warming events into 21st century environmental management demands clear guidelines.

"Ongoing climate change poses an important challenge for biodiversity management, and our research shows how the recent geological past can inform effective conservation practice and policy," says co-author Stephen Jackson from the U.S. Geological Survey.

"Conservation biologists are now taking full advantage of the long-term history of the planet as recorded in paleo-archives, such as those gathered by our team, to understand biological responses to abrupt climate changes of the past, quantify trends, and develop scenarios of future biodiversity loss from climate change," says Associate Professor Fordham.

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New observations of black hole devouring a star reveal rapid disk formation

 When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole. Astronomers study the light from these "tidal disruption events" (TDEs) for clues to the feeding behavior of the supermassive black holes lurking at the centers of galaxies.

New TDE observations led by astronomers at UC Santa Cruz now provide clear evidence that debris from the star forms a rotating disk, called an accretion disk, around the black hole. Theorists have been debating whether an accretion disk can form efficiently during a tidal disruption event, and the new findings, accepted for publication in the Astrophysical Journal and available online, should help resolve that question, said first author Tiara Hung, a postdoctoral researcher at UC Santa Cruz.

"In classical theory, the TDE flare is powered by an accretion disk, producing x-rays from the inner region where hot gas spirals into the black hole," Hung said. "But for most TDEs, we don't see x-rays -- they mostly shine in the ultraviolet and optical wavelengths -- so it was suggested that, instead of a disk, we're seeing emissions from the collision of stellar debris streams."

Coauthors Enrico Ramirez-Ruiz, professor of astronomy and astrophysics at UCSC, and Jane Dai at the University of Hong Kong developed a theoretical model, published in 2018, that can explain why x-rays are usually not observed in TDEs despite the formation of an accretion disk. The new observations provide strong support for this model.

"This is the first solid confirmation that accretion disks form in these events, even when we don't see x-rays," Ramirez-Ruiz said. "The region close to the black hole is obscured by an optically thick wind, so we don't see the x-ray emissions, but we do see optical light from an extended elliptical disk."

The telltale evidence for an accretion disk comes from spectroscopic observations. Coauthor Ryan Foley, assistant professor of astronomy and astrophysics at UCSC, and his team began monitoring the TDE (named AT 2018hyz) after it was first detected in November 2018 by the All Sky Automated Survey for SuperNovae (ASAS-SN). Foley noticed an unusual spectrum while observing the TDE with the 3-meter Shane Telescope at UC's Lick Observatory on the night of January 1, 2019.

"My jaw dropped, and I immediately knew this was going to be interesting," he said. "What stood out was the hydrogen line -- the emission from hydrogen gas -- which had a double-peaked profile that was unlike any other TDE we'd seen."

Foley explained that the double peak in the spectrum results from the Doppler effect, which shifts the frequency of light emitted by a moving object. In an accretion disk spiraling around a black hole and viewed at an angle, some of the material will be moving toward the observer, so the light it emits will be shifted to a higher frequency, and some of the material will be moving away from the observer, its light shifted to a lower frequency.

"It's the same effect that causes the sound of a car on a race track to shift from a high pitch as the car comes toward you to a lower pitch when it passes and starts moving away from you," Foley said. "If you're sitting in the bleachers, the cars on one turn are all moving toward you and the cars on the other turn are moving away from you. In an accretion disk, the gas is moving around the black hole in a similar way, and that's what gives the two peaks in the spectrum."

The team continued to gather data over the next few months, observing the TDE with several telescopes as it evolved over time. Hung led a detailed analysis of the data, which indicates that disk formation took place relatively quickly, in a matter of weeks after the disruption of the star. The findings suggest that disk formation may be common among optically detected TDEs despite the rarity of double-peaked emission, which depends on factors such as the inclination of the disk relative to observers.

"I think we got lucky with this one," Ramirez-Ruiz said. "Our simulations show that what we observe is very sensitive to the inclination. There is a preferred orientation to see these double-peak features, and a different orientation to see x-ray emissions."

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Why 'one day at a time' works for recovering alcoholics

 "One day at a time" is a mantra for recovering alcoholics, for whom each day without a drink builds the strength to go on to the next. A new brain imaging study by Yale researchers shows why the approach works.

Imaging scans of those diagnosed with alcohol use disorder (AUD) taken one day to two weeks after their last drink reveal associated disruptions of activity between the ventromedial prefrontal cortex and striatum, a brain network linked to decision making. The more recent the last drink, the more severe the disruption, and the more likely the alcoholics will resume heavy drinking and jeopardize their treatment and recovery, researchers report Aug. 28 in the American Journal of Psychiatry.

However, the researchers also found that the severity of disruption between these brain regions diminishes gradually the longer AUD subjects abstain from alcohol.

"For people with AUD, the brain takes a long time to normalize, and each day is going to be a struggle," said Rajita Sinha, the Foundations Fund Professor of Psychiatry and professor in the Child Study Center, professor of neuroscience and senior author of the study. "For these people, it really is 'one day at a time.'"

The imaging studies can help reveal who is most at risk of relapse and underscore the importance of extensive early treatment for those in their early days of sobriety, Sinha said.

"When people are struggling, it is not enough for them to say, 'Okay, I didn't drink today so I'm good now.'" Sinha said. "It doesn't work that way."

The study also suggests it may be possible to develop medications specifically to help those with the greatest brain disruptions during their early days of alcohol treatment. For instance, Sinha and Yale colleagues are currently investigating whether existing high blood pressure medication can help reduce disruptions in the prefrontal-striatal network and improve chances of long-term abstinence in AUD patients.

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Hubble maps giant halo around Andromeda Galaxy

 In a landmark study, scientists using NASA's Hubble Space Telescope have mapped the immense envelope of gas, called a halo, surrounding the Andromeda galaxy, our nearest large galactic neighbor. Scientists were surprised to find that this tenuous, nearly invisible halo of diffuse plasma extends 1.3 million light-years from the galaxy -- about halfway to our Milky Way -- and as far as 2 million light-years in some directions. This means that Andromeda's halo is already bumping into the halo of our own galaxy.

They also found that the halo has a layered structure, with two main nested and distinct shells of gas. This is the most comprehensive study of a halo surrounding a galaxy.

"Understanding the huge halos of gas surrounding galaxies is immensely important," explained co-investigator Samantha Berek of Yale University in New Haven, Connecticut. "This reservoir of gas contains fuel for future star formation within the galaxy, as well as outflows from events such as supernovae. It's full of clues regarding the past and future evolution of the galaxy, and we're finally able to study it in great detail in our closest galactic neighbor."

"We find the inner shell that extends to about a half million light-years is far more complex and dynamic," explained study leader Nicolas Lehner of the University of Notre Dame in Indiana. "The outer shell is smoother and hotter. This difference is a likely result from the impact of supernova activity in the galaxy's disk more directly affecting the inner halo."

A signature of this activity is the team's discovery of a large amount of heavy elements in the gaseous halo of Andromeda. Heavier elements are cooked up in the interiors of stars and then ejected into space -- sometimes violently as a star dies. The halo is then contaminated with this material from stellar explosions.

The Andromeda galaxy, also known as M31, is a majestic spiral of perhaps as many as 1 trillion stars and comparable in size to our Milky Way. At a distance of 2.5 million light-years, it is so close to us that the galaxy appears as a cigar-shaped smudge of light high in the autumn sky. If its gaseous halo could be viewed with the naked eye, it would be about three times the width of the Big Dipper. This would easily be the biggest feature on the nighttime sky.

Through a program called Project AMIGA (Absorption Map of Ionized Gas in Andromeda), the study examined the light from 43 quasars -- the very distant, brilliant cores of active galaxies powered by black holes -- located far beyond Andromeda. The quasars are scattered behind the halo, allowing scientists to probe multiple regions. Looking through the halo at the quasars' light, the team observed how this light is absorbed by the Andromeda halo and how that absorption changes in different regions. The immense Andromeda halo is made of very rarified and ionized gas that doesn't emit radiation that is easily detectable. Therefore, tracing the absorption of light coming from a background source is a better way to probe this material.

The researchers used the unique capability of Hubble's Cosmic Origins Spectrograph (COS) to study the ultraviolet light from the quasars. Ultraviolet light is absorbed by Earth's atmosphere, which makes it impossible to observe with ground-based telescopes. The team used COS to detect ionized gas from carbon, silicon, and oxygen. An atom becomes ionized when radiation strips one or more electrons from it.

Andromeda's halo has been probed before by Lehner's team. In 2015, they discovered that the Andromeda halo is large and massive. But there was little hint of its complexity; now, it's mapped out in more detail, leading to its size and mass being far more accurately determined.

"Previously, there was very little information -- only six quasars -- within 1 million light-years of the galaxy. This new program provides much more information on this inner region of Andromeda's halo," explained co-investigator J. Christopher Howk, also of Notre Dame. "Probing gas within this radius is important, as it represents something of a gravitational sphere of influence for Andromeda."

Because we live inside the Milky Way, scientists cannot easily interpret the signature of our own galaxy's halo. However, they believe the halos of Andromeda and the Milky Way must be very similar since these two galaxies are quite similar. The two galaxies are on a collision course, and will merge to form a giant elliptical galaxy beginning about 4 billion years from now.

Scientists have studied gaseous halos of more distant galaxies, but those galaxies are much smaller on the sky, meaning the number of bright enough background quasars to probe their halo is usually only one per galaxy. Spatial information is therefore essentially lost. With its close proximity to Earth, the gaseous halo of Andromeda looms large on the sky, allowing for a far more extensive sampling.

"This is truly a unique experiment because only with Andromeda do we have information on its halo along not only one or two sightlines, but over 40," explained Lehner. "This is groundbreaking for capturing the complexity of a galaxy halo beyond our own Milky Way."

In fact, Andromeda is the only galaxy in the universe for which this experiment can be done now, and only with Hubble. Only with an ultraviolet-sensitive future space telescope will scientists be able to routinely undertake this type of experiment beyond the approximately 30 galaxies comprising the Local Group.

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Rare encounters between cosmic heavyweights

 A cosmic dance between two merging galaxies, each one containing a supermassive black hole that's rapidly feeding on so much material it creates a phenomenon known as a quasar, is a rare find.

Astronomers have discovered several pairs of such merging galaxies, or luminous "dual" quasars, using three Maunakea Observatories in Hawaii -- Subaru Telescope, W. M. Keck Observatory, and Gemini Observatory.

These dual quasars are so rare, a research team led by the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo estimates only 0.3% of all known quasars have two supermassive black holes that are on a collision course with each other.

The study is published in the August 26, 2020 issue of the Astrophysical Journal.

"In spite of their rarity, they represent an important stage in the evolution of galaxies, where the central giant is awakened, gaining mass, and potentially impacting the growth of its host galaxy," said Shenli Tang, a graduate student at the University of Tokyo and co-author of the study.

Quasars are one of the most luminous, energetic objects known in the universe, powered by supermassive black holes that are millions to billions times more massive than our Sun. As material swirls around a black hole at the center of a galaxy, it is heated to high temperatures, releasing so much light that the quasar can outshine its host galaxy.

This makes a merging pair of galaxies with quasar activity hard to detect; it is difficult to separate the light from the two quasars because they are in such close proximity to each other. Also, observing a wide enough area of the sky to catch these rare events in sufficient numbers is a challenge.

To overcome these obstacles, the team took advantage of a sensitive wide survey of the sky using the Hyper Suprime-Cam (HSC) camera on the Subaru Telescope.

"To make our job easier, we started by looking at the 34,476 known quasars from the Sloan Digital Sky Survey with HSC imaging to identify those having two (or more) distinct centers," said lead author John Silverman of the Kavli Institute for the Physics and Mathematics of the Universe. "Honestly, we didn't start out looking for dual quasars. We were examining images of these luminous quasars to determine which type of galaxies they preferred to reside in when we started to see cases with two optical sources in their centers where we only expected one."

The team identified 421 promising cases. However, there was still the chance many of these were not bona-fide dual quasars but rather chance projections such as starlight from our own galaxy. Confirmation required detailed analysis of the light from the candidates to search for definitive signs of two distinct quasars.

Using Keck Observatory's Low Resolution Imaging Spectrometer (LRIS) and Gemini Observatory's Near-Infrared Integral Field Spectrometer, Silverman and his team identified three dual quasars, two of which were previously unknown. Each object in the pair showed the signature of gas moving at thousands of kilometers per second under the influence of a supermassive black hole.

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Spouses shed more pounds together than alone

 Weight loss is most successful in heart attack survivors when partners join in the effort to diet, according to research presented today at ESC Congress 2020.

"Lifestyle improvement after a heart attack is a crucial part of preventing repeat events," said study author Ms. Lotte Verweij, a registered nurse and PhD student, Amsterdam University of Applied Sciences, the Netherlands. "Our study shows that when spouses join the effort to change habits, patients have a better chance of becoming healthier -- particularly when it comes to losing weight."

The RESPONSE-2 trial previously found that heart attack survivors referred to programmes for weight reduction, physical activity, and smoking cessation were more likely to modify behaviours compared to those receiving usual care. In both groups, living with a partner was linked with greater success in shifting bad habits. The most notable improvements were in patients who took part in lifestyle programmes and lived with a partner.

This follow-up study investigated whether partner involvement in lifestyle programmes had an impact on behaviour change. "If partners contribute to adopting healthy habits, it could become an important recommendation to avoid recurrent heart attacks," explained Ms. Verweij.

A total of 824 patients were randomly assigned to the intervention group (lifestyle programmes on top of usual care) or control group (usual care alone).

This analysis focused on the 411 patients in the intervention group, who were referred to up to three lifestyle programmes for weight reduction, physical activity, and smoking cessation depending on their needs and preferences. Partners could attend for free and nurses encouraged them to participate. Partner participation was defined as attending at least once.

Nearly half (48%) of partners participated in the lifestyle interventions. Compared to those without a partner, patients with a participating partner were more than twice as likely (odds ratio 2.45) to improve in at least one of the three areas (weight loss, exercise, smoking cessation) within a year.

When the influence of partners was analysed on the three areas separately, patients with a participating partner were most successful in reducing weight compared to patients without a partner (odds ratio 2.71).

"Patients with partners who joined the weight loss programme lost more weight compared to patients with a partner who did not join the programme," said Ms. Verweij.

She continued: "Couples often have comparable lifestyles and changing habits is difficult when only one person is making the effort. Practical issues come into play, such as grocery shopping, but also psychological challenges, where a supportive partner may help maintain motivation."

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Japanese sake: the new pick-me-up? Yeast strain makes fatigue-fighting ornithine

 Fans of sake, the traditional Japanese alcoholic beverage, may have even more reason to enjoy it now: Japanese scientists have discovered that a mutant strain of sake yeast produces high levels of the amino acid ornithine.

In a study published this month in Metabolic Engineering, researchers from the Nara Institute of Science and Technology and the Nara Prefecture Institute of Industrial Development have revealed that a mutant strain of sake yeast produces 10 times the amount of the amino acid ornithine compared with the parent yeast strain.

Ornithine is a non-protein-making amino acid and a precursor to two amino acids -- arginine and proline. It has been found to perform several physiological functions, such as reducing fatigue and improving sleep quality.

"We wanted to obtain sake yeast strains with improved ethanol tolerance," says a first author of this article, Masataka Ohashi. "During sake fermentation, the yeast is exposed to high concentrations of ethanol, which impedes yeast cell growth, viability and fermentation. Increased ethanol tolerance in sake yeast strains could improve ethanol production and reduce fermentation time."

To find ethanol-tolerant yeast strains, the researchers isolated mutants that accumulated proline, which can alleviate ethanol toxicity, using a conventional mutagenesis (i.e., one that doesn't involve genetic modification). They also conducted whole genome sequencing analysis, and performed brewing tests with sake yeast strains. Then they identified and analyzed a new mutation in a gene that encodes a variant of N-acetyl glutamate kinase that increases intracellular ornithine level.

"We previously constructed self-cloning industrial yeast strains that accumulate proline to increase ethanol tolerance and productivity of yeast," explains Prof. Hiroshi Takagi, a corresponding author. "But those yeasts have not been yet acceptable to consumers because they're considered to be genetically modified, even though a self-cloning yeast has no foreign genes or DNA sequences -- they only have yeast DNA."

The researchers successfully isolated non-genetically modified yeasts that produced 10 times the amount of ornithine compared with the parent strain, which is widely used in Japanese sake breweries, and the sake brewed with them contained 4-5 times more ornithine.

The results of this study will contribute to the development of improved yeast strains for production of high levels of ornithine, and the strain obtained in this study could be readily applied to sake, wine, and beer brewing. Ornithine-accumulating yeast strains could also be used in the production of ornithine-rich dietary supplements made from these yeasts and their products.

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Meteorite strikes may create unexpected form of silica

 When a meteorite hurtles through the atmosphere and crashes to Earth, how does its violent impact alter the minerals found at the landing site? What can the short-lived chemical phases created by these extreme impacts teach scientists about the minerals existing at the high-temperature and pressure conditions found deep inside the planet?

New work led by Carnegie's Sally June Tracy examined the crystal structure of the silica mineral quartz under shock compression and is challenging longstanding assumptions about how this ubiquitous material behaves under such intense conditions. The results are published in Science Advances.

"Quartz is one of the most abundant minerals in Earth's crust, found in a multitude of different rock types," Tracy explained. "In the lab, we can mimic a meteorite impact and see what happens."

Tracy and her colleagues -- Washington State University's (WSU) Stefan Turneaure and Princeton University's Thomas Duffy, a former Carnegie Fellow -- used a specialized cannon-like gas gun to accelerate projectiles into quartz samples at extremely high speeds -- several times faster than a bullet fired from a rifle. Special x-ray instruments were used to discern the crystal structure of the material that forms less than one-millionth of a second after impact. Experiments were carried out at the Dynamic Compression Sector (DCS), which is operated by WSU and located at the Advanced Photon Source, Argonne National Laboratory.

Quartz is made up of one silicon atom and two oxygen atoms arranged in a tetrahedral lattice structure. Because these elements are also common in the silicate-rich mantle of the Earth, discovering the changes quartz undergoes at high-pressure and -temperature conditions, like those found in the Earth's interior, could also reveal details about the planet's geologic history.

When a material is subjected to extreme pressures and temperatures, its internal atomic structure can be re-shaped, causing its properties to shift. For example, both graphite and diamond are made from carbon. But graphite, which forms at low pressure, is soft and opaque, and diamond, which forms at high pressure, is super-hard and transparent. The different arrangements of carbon atoms determine their structures and their properties, and that in turn affects how we engage with and use them.

Despite decades of research, there has been a long-standing debate in the scientific community about what form silica would take during an impact event, or under dynamic compression conditions such as those deployed by Tracy and her collaborators. Under shock loading, silica is often assumed to transform to a dense crystalline form known as stishovite -- a structure believed to exist in the deep Earth. Others have argued that because of the fast timescale of the shock the material will instead adopt a dense, glassy structure.

Tracy and her team were able to demonstrate that counter to expectations, when subjected to a dynamic shock of greater than 300,000 times normal atmospheric pressure, quartz undergoes a transition to a novel disordered crystalline phase, whose structure is intermediate between fully crystalline stishovite and a fully disordered glass. However, the new structure cannot last once the burst of intense pressure has subsided.

"Dynamic compression experiments allowed us to put this longstanding debate to bed," Tracy concluded. "What's more, impact events are an important part of understanding planetary formation and evolution and continued investigations can reveal new information about these processes."

This research was supported by the Defense Threat Reduction Agency and the NSF. Washington State University (WSU) provided experimental support through awards from the U.S. Department of Energy (DOE)/National Nuclear Security Agency (NNSA).

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How cold was the ice age? Researchers now know

 A University of Arizona-led team has nailed down the temperature of the last ice age -- the Last Glacial Maximum of 20,000 years ago -- to about 46 degrees Fahrenheit.

Their findings allow climate scientists to better understand the relationship between today's rising levels of atmospheric carbon dioxide -- a major greenhouse gas -- and average global temperature.

The Last Glacial Maximum, or LGM, was a frigid period when huge glaciers covered about half of North America, Europe and South America and many parts of Asia, while flora and fauna that were adapted to the cold thrived.

"We have a lot of data about this time period because it has been studied for so long," said Jessica Tierney, associate professor in the UArizona Department of Geosciences. "But one question science has long wanted answers to is simple: How cold was the ice age?"

Tracking Temperature

Tierney is lead author of a paper published today in Nature that found that the average global temperature of the ice age was 6 degrees Celsius (11 F) cooler than today. For context, the average global temperature of the 20th century was 14 C (57 F).

"In your own personal experience that might not sound like a big difference, but, in fact, it's a huge change," Tierney said.

She and her team also created maps to illustrate how temperature differences varied in specific regions across the globe.

"In North America and Europe, the most northern parts were covered in ice and were extremely cold. Even here in Arizona, there was big cooling," Tierney said. "But the biggest cooling was in high latitudes, such as the Arctic, where it was about 14 C (25 F) colder than today."

Their findings fit with scientific understanding of how Earth's poles react to temperature changes.

"Climate models predict that the high latitudes will get warmer faster than low latitudes," Tierney said. "When you look at future projections, it gets really warm over the Arctic. That's referred to as polar amplification. Similarly, during the LGM, we find the reverse pattern. Higher latitudes are just more sensitive to climate change and will remain so going forward."

Counting Carbon

Knowing the temperature of the ice age matters because it is used to calculate climate sensitivity, meaning how much the global temperature shifts in response to atmospheric carbon.

Tierney and her team determined that for every doubling of atmospheric carbon, global temperature should increase by 3.4 C (6.1 F), which is in the middle of the range predicted by the latest generation of climate models (1.8 to 5.6 C).

Atmospheric carbon dioxide levels during the ice age were about 180 parts per million, which is very low. Before the Industrial Revolution, levels rose to about 280 parts per million, and today they've reached 415 parts per million.

"The Paris Agreement wanted to keep global warming to no larger than 2.7 F (1.5 C) over pre-industrial levels, but with carbon dioxide levels increasing the way they are, it would be extremely difficult to avoid more than 3.6 F (2 C) of warming," Tierney said. "We already have about 2 F (1.1 C) under our belt, but the less warm we get the better, because the Earth system really does respond to changes in carbon dioxide."

Making a Model

Since there were no thermometers in the ice age, Tierney and her team developed models to translate data collected from ocean plankton fossils into sea-surface temperatures. They then combined the fossil data with climate model simulations of the LGM using a technique called data assimilation, which is used in weather forecasting.

"What happens in a weather office is they measure the temperature, pressure, humidity and use these measurements to update a forecasting model and predict the weather," Tierney said. "Here, we use the Boulder, Colorado-based National Center for Atmospheric Research climate model to produce a hindcast of the LGM, and then we update this hindcast with the actual data to predict what the climate was like."

In the future, Tierney and her team plan to use the same technique to recreate warm periods in Earth's past.

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Key to fish family's land-walking abilities revealed in study of Asia's hillstream loaches

 In a study published in the Journal of Morphology, a team of researchers from New Jersey Institute of Technology (NJIT), Florida Museum of Natural History, Louisiana State University and Thailand's Maejo University have successfully pieced together the ancestral relationships that make up the family tree of hillstream loaches (Balitoridae), detailing for the first time a range of unusual pelvic adaptations across the family that have given some of its members an ability to crawl, or even walk as salamanders do, to navigate terrestrial surfaces.

The team's DNA-based comparative analysis of the fish family, known to currently encompass more than 100 species native to South and Southeast Asia, is the first of its kind to include Cryptotora thamicola -- the only living species of fish known to walk on land in a step pattern similar to tetrapods, or four-limbed vertebrates such as reptiles and amphibians.

The results have revealed that three dominant variations of pelvic anatomy in the family, notably including key variations of a robust pelvic girdle and elongated sacral rib among many loaches, which researchers expect are central in explaining the different degrees of land-walking behavior exhibited by the fishes. The team says that the family's modified pelvic features enabling terrestrial locomotion, which were found most pronounced in Cryptotora thamicola, may have been adapted to enhance their odds of survival in rivers and other fast-moving water environments that many Balitoridae inhabit today.

"The modified morphology of these Balitoridae, particularly the enlarged sacral rib connecting the pelvic plate to the vertebral column, is a big part of why studying this family is so exciting," said Callie Crawford, the study's corresponding author and Ph.D. candidate at NJIT's Department of Biological Sciences. "These loaches have converged on a structural requirement to support terrestrial walking not seen in other fishes. What we've discovered is three anatomical groupings that have major implications for the biomechanics of terrestrial locomotion of these loaches, and the relationships among these fishes suggest that the ability to adapt to fast-flowing rivers may be what was passed on genetically, more than the specific morphology itself."

"Now that we have revealed a spectrum of pelvic morphologies among these fishes, we can compare the extent of skeletal support with the walking performance in a species," said Brooke Flammang, the study's lead principal investigator and assistant professor of biology at NJIT. "This will allow us to measure the mechanical contribution of robust hips to terrestrial locomotion."

Unlike most living fishes that feature pelvic fins located more anteriorly and attached to the pectoral girdle, balitorids typically boast a skeletal connection between the pelvic plate (basipterygium) and the vertebral column via a modified sacral rib and its distal ligament. These modifications are understood to help generate force against the ground useful for navigating land. The most extreme example emerged in 2016 with the discovery of Cryptotora thamicola in the fast-flowing aquatic conditions of the Tham Maelana and Tham Susa karst cave systems in northern Thailand. NJIT researchers then first identified that the rare species used a robust pelvic girdle attached to its vertebral column to walk and climb waterfalls with a salamander-like gait.

"This trait is likely key to helping these fishes avoid being washed away in the fast-flowing environment that they live in," said Zach Randall, co-author of the paper and biological scientist at Florida Museum of Natural History. "What's really cool about this paper is that it shows with high detail that robust pelvic girdles are more common than we thought in the hillstream loach family."

"The sacral ribs allow forces from the fins pressing against the ground to be transferred to the body so that every time the fin pushes down during a step, the body is pushed up and forward," explained Flammang. "The increased surface area of the more modified sacral ribs also offers more room for muscle attachment, so fishes such as Cryptotora thamicola can rotate their hips during walking, producing a salamander-like gait."

River Loach Family Factions

To better understand the evolution of the river loach family, the team conducted a broad sampling of ?CT-scan data taken from 29 representative specimens, analyzing and comparing skeletal structures, muscle morphology as well as sacral rib shape across 14 of the 16 balitorid genera. The team also sampled genomic datasets of 72 loaches across seven families to reconstruct the evolutionary relationships in the Ballitoridae tree of life. "We were able to use a large survey of museum specimens and CT scanning to incorporate data even from specimens that didn't have tissue or genetic data intact," noted Randall.

The results showed that the loaches fall into three distinct morphotypes, which are expected to correlate to how well they are able to maneuver on land: species with a long, narrow rib that meets the pelvic plate; species with a thicker, slightly curved rib meeting the pelvic plate; and species with a robust crested rib interlocking with the pelvic plate. Of the species sampled, eleven fell into the third category with advanced land-walking abilities, such as Cryptotora thamicola, displaying the most robust sacral rib connection between the basipterygium and vertebral column.

"Our analysis showed that the morphotypes are not grouped by closely related taxa, but instead appear spread out across the phylogeny. That indicates to us that the extent of the modification of these features is less reflecting shared ancestry and more likely a product of adaptation to the flow regimes of their environments," explained Crawford. "To better understand how and why these distinct morphotypes developed, we need more knowledge of the habitat of each species, including water flow rates, substrate types and how the rivers and streams change between rainy and dry seasons."

Crawford and colleagues now aim to further investigate the stability physics and muscular forces at play that allow certain species to push their bodies off their ground as they walk. The team, including a recent Rutgers University graduate, Amani Webber-Schultz, recently completed fieldwork in Thailand earlier this year to collect more balitorid specimens, which they are studying using high-speed videos of the fishes walking.

Read more at Science Daily

New neural network differentiates Middle and Late Stone Age toolkits

 MSA toolkits first appear some 300 thousand years ago, at the same time as the earliest fossils of Homo sapiens, and are still in use 30 thousand years ago. However, from 67 thousand years ago, changes in stone tool production indicate a marked shift in behaviour; the new toolkits that emerge are labelled LSA and remained in use into the recent past. A growing body of evidence suggests that the transition from MSA to LSA was not a linear process, but occurred at different times in different places. Understanding this process is important to examine what drives cultural innovation and creativity, and what explains this critical behavioural change. Defining differences between the MSA and LSA is an important step towards this goal.

"Eastern Africa is a key region to examine this major cultural change, not only because it hosts some of the youngest MSA sites and some of the oldest LSA sites, but also because the large number of well excavated and dated sites make it ideal for research using quantitative methods," says Dr. Jimbob Blinkhorn, an archaeologist from the Pan African Evolution Research Group, Max Planck Institute for the Science of Human History and the Centre for Quaternary Research, Department of Geography, Royal Holloway. "This enabled us to pull together a substantial database of changing patterns of stone tool production and use, spanning 130 to 12 thousand years ago, to examine the MSA-LSA transition."

The study examines the presence or absence of 16 alternate tool types across 92 stone tool assemblages, but rather than focusing on them individually, emphasis is placed on the constellations of tool forms that frequently occur together.

"We've employed an Artificial Neural Network (ANN) approach to train and test models that differentiate LSA assemblages from MSA assemblages, as well as examining chronological differences between older (130-71 thousand years ago) and younger (71-28 thousand years ago) MSA assemblages with a 94% success rate," says Dr. Matt Grove, an archaeologist at the University of Liverpool.

Artificial Neural Networks (ANNs) are computer models intended to mimic the salient features of information processing in the brain. Like the brain, their considerable processing power arises not from the complexity of any single unit but from the action of many simple units acting in parallel. Despite the widespread use of ANNs today, applications in archaeological research remain limited.

"ANNs have sometimes been described as a 'black box' approach, as even when they are highly successful, it may not always be clear exactly why," says Grove. "We employed a simulation approach that breaks open this black box to understand which inputs have a significant impact on the results. This enabled us to identify how patterns of stone tool assemblage composition vary between the MSA and LSA, and we hope this demonstrates how such methods can be used more widely in archaeological research in the future."

"The results of our study show that MSA and LSA assemblages can be differentiated based on the constellation of artefact types found within an assemblage alone," Blinkhorn adds. "The combined occurrence of backed pieces, blade and bipolar technologies together with the combined absence of core tools, Levallois flake technology, point technology and scrapers robustly identifies LSA assemblages, with the opposite pattern identifying MSA assemblages. Significantly, this provides quantified support to qualitative differences noted by earlier researchers that key typological changes do occur with this cultural transition."

Read more at Science Daily

Why flat-faced dogs remain popular despite health problems

 Owners of bulldogs, French bulldogs and pugs are highly likely to want to own their breed again in the future, and to recommend their breed to other owners, according to a study published August 26, 2020 in the open-access journal PLOS ONE by Rowena Packer of the Royal Veterinary College, UK, and colleagues. The development of breed loyalty toward these so-called brachycephalic (flat-faced) dogs may lead to their continued proliferation and popularity, despite their substantial health risks.

In the past decade, the popularity of brachycephalic dogs has dramatically increased worldwide. But these breeds are strongly predisposed to a range of severe disorders, including respiratory disease, eye disease, spinal disease, heat stroke and pneumonia, and their lifespan is reduced by on average four years compared to dogs with longer muzzles. Some veterinarians consider bulldogs, French bulldogs and pugs as having health and welfare too compromised to continue breeding, while owners of pets with chronic illnesses report greater psychological distress and a lower quality of life. It is important to understand factors that influence breed choice to avoid the future proliferation of breeds that are prone to substantial health risks. Toward this goal, Packer and colleagues conducted the first large-scale study to explore owners' desires to reacquire or recommend the most popular brachycephalic breeds in the UK.

Among the 2168 owners surveyed, 93% would choose to own their current breed again in the future, and two-thirds would recommend their current breed to a potential first-time dog owner. The likelihood of reacquisition or recommendation is increased by first-time ownership and increased strength of the dog-owner relationship, and is decreased by an increased number of health problems and dog behavior being worse than expected. Owners recommend their breed because of positive behavioral attributes for a companion dog, breed suitability for a sedentary lifestyle with limited space, and suitability for households with children. Owners recommended against their breed due to the high prevalence of health problems, expense of ownership, ethical and welfare issues associated with breeding brachycephalic dogs, negative effects upon owner lifestyle and negative behavioral attributes. According to the authors, these results can be used to inform interventions that highlight undesirable traits of brachycephalic dogs and desirable traits of other breeds to control the population boom in brachycephalic breeds in the long term.

The authors add: "Although dog breed popularity often follows a boom and bust pattern, our results are of real concern as they indicate that this 'brachy boom' is here to stay. Owners are becoming hooked on the loving personalities of these sweet dogs, but also accepting and normalising their shocking health issues."

From Science Daily

Sleep duration, efficiency and structure change in space

 It's hard to get a good night's sleep in space. An evaluation of astronauts serving on the Mir space station found that they experienced shorter sleep durations, more wakefulness, and changes in the structure of their sleep cycles while in microgravity.

Researchers at Harvard College, Harvard Medical School, and NASA Ames Research Center studied the sleep patterns of four cosmonauts and one astronaut before, during and after spaceflight to conduct missions on the space station. Preliminary results show that they slept an average of only 5.7 hours in space, compared with 6.7 hours on Earth. They also spent significantly more time awake in bed, leading to a 17.7% reduction in sleep efficiency.

In space their time in non-REM and REM sleep decreased by 14.1% and 25.8% respectively. On average it also took about 90 minutes after falling asleep for astronauts to reach their first episode of REM sleep in space, nearly 1.5 times longer than on Earth. In contrast, most sleep measures were stable across the inflight phase, with the exception of a decrease in the amount of time spent in bed and an increase in the length of time it took to fall asleep after going to bed.

"There were marked shifts in sleep architecture compared to baseline, and some of these evolved over the course of the mission," said lead author Oliver Piltch, an undergraduate researcher at Harvard College. "Our findings were consistent with previous studies that focus on the issue of sleep continuity. We found significant decreases in sleep efficiency during spaceflight despite similar times in bed."

Piltch said scientists need to understand how sleep is affected by spaceflight to better equip astronauts for success on long-duration flights, like a trip to Mars or the Moon. He noted that the research also has implications for sleep on Earth.

"The significant sleep changes induced by the extreme environmental conditions of spaceflight can magnify and help reveal similar, though potentially less noticeable, changes that are induced by the more moderate conditions of Earth," he said. "Our results support other studies indicating that sleep architecture can adapt to different environments. Also, the sleep deficits that our subjects were facing while working around the clock in a high-pressure environment provide further evidence for the danger of stress and shift-work schedules for humans anywhere."

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Tracing the cosmic origin of complex organic molecules with their radiofrequency footprint

 The origin of life on Earth is a topic that has piqued human curiosity since probably before recorded history began. But how did the organic matter that constitutes lifeforms even arrive at our planet? Though this is still a subject of debate among scholars and practitioners in related fields, one approach to answering this question involves finding and studying complex organic molecules (COMs) in outer space.

Many scientists have reported finding all sorts of COMs in molecular clouds -- gigantic regions of interstellar space that contain various types of gases. This is generally done using radio telescopes, which measure and record radiofrequency waves to provide a frequency profile of the incoming radiation called spectrum. Molecules in space are usually rotating in various directions, and they emit or absorb radio waves at very specific frequencies when their rotational speed changes. Current physics and chemistry models allow us to approximate the composition of what a radio telescope is pointed at, via analysis of the intensity of the incoming radiation at these frequencies.

In a recent study published in Monthly Notices of the Royal Astronomical Society, Dr Mitsunori Araki from Tokyo University of Science, along with other scientists from across Japan, tackled a difficult question in the search for interstellar COMs: how can we assert the presence of COMs in the less dense regions of molecular clouds? Because molecules in space are mostly energized by collisions with hydrogen molecules, COMs in the low-density regions of molecular clouds emit less radio waves, making it difficult for us to detect them. However, Dr Araki and his team took a different approach based on a special organic molecule called acetonitrile (CH3CN).

Acetonitrile is an elongated molecule that has two independent ways of rotating: around its long axis, like a spinning top, or as if it were a pencil spinning around your thumb. The latter type of rotation tends to spontaneously slow down due to the emission of radio waves and, in the low-density regions of molecular clouds, it naturally becomes less energetic or "cold."

In contrast, the other type of rotation does not emit radiation and therefore remains active without slowing down. This particular behavior of the acetonitrile molecule was the basis on which Dr Araki and his team managed to detect it. He explains: "In low-density regions of molecular clouds, the proportion of acetonitrile molecules rotating like a spinning top should be higher. Thus, it can be inferred that an extreme state in which a lot of them would be rotating in this way should exist. Our research team was, however, the first to predict its existence, select astronomical bodies that could be observed, and actually begin exploration."

Instead of going for radio wave emissions, they focused on radio wave absorption. The "cold" state of the low-density region, if populated by acetonitrile molecules, should have a predictable effect on the radiation that originates in celestial bodies like stars and goes through it. In other words, the spectrum of a radiating body that we perceive on Earth as being "behind" a low-density region would be filtered by acetonitrile molecules spinning like a top in a calculable way, before it reaches our telescope on earth. Therefore, Dr Araki and his team had to carefully select radiating bodies that could be used as an appropriate "background light" to see if the shadow of "cold" acetonitrile appeared in the measured spectrum. To this end, they used the 45 m radio telescope of the Nobeyama Radio Observatory, Japan, to explore this effect in a low-density region around the "Sagittarius molecular cloud Sgr B2(M)," one of the largest molecular clouds in the vicinity of the center of our galaxy.

After careful analysis of the spectra measured, the scientists concluded that the region analyzed was rich in acetonitrile molecules rotating like a spinning top; the proportion of molecules rotating this way was actually the highest ever recorded. Excited about the results, Dr Araki remarks: "By considering the special behavior of acetonitrile, its amount in the low-density region around Sgr B2(M) can be accurately determined. Because acetonitrile is a representative COM in space, knowing its amount and distribution though space can help us probe further into the overall distribution of organic matter."

Read more at Science Daily

Effectiveness of cloth masks depends on type of covering

 Months into the COVID-19 pandemic, wearing a mask while out in public has become the recommended practice. However, many still question the effectiveness of this.

To allay these doubts, Padmanabha Prasanna Simha, from the Indian Space Research Organisation, and Prasanna Simha Mohan Rao, from the Sri Jayadeva Institute of Cardiovascular Sciences and Research, experimentally visualized the flow fields of coughs under various common mouth covering scenarios. They present their findings in the journal Physics of Fluids, from AIP Publishing.

"If a person can reduce the extent of how much they contaminate the environment by mitigating the spread, it's a far better situation for other healthy individuals who may enter places that have such contaminated areas," Simha said.

Density and temperature are intricately related, and coughs tend to be warmer than their surrounding area. Tapping into this connection, Simha and Rao utilized a technique called schlieren imaging, which visualizes changes in density, to capture pictures of voluntary coughs from five test subjects. By tracking the motion of a cough over successive images, the team estimated velocity and spread of the expelled droplets.

Unsurprisingly, they found N95 masks to be the most effective at reducing the horizontal spread of a cough. The N95 masks reduced a cough's initial velocity by up to a factor of 10 and limit its spread to between 0.1 and 0.25 meters.

An uncovered cough, in contrast, can travel up to 3 meters, but even a simple disposable mask can bring this all the way down to 0.5 meters.

"Even if a mask does not filter out all the particles, if we can prevent clouds of such particles from traveling very far, it's better than not doing anything," said Simha. "In situations where sophisticated masks are not available, any mask is better than no mask at all for the general public in slowing the spread of infection."

Some of the other comparisons, however, were striking.

For example, using an elbow to cover up a cough is typically considered a good alternative in a pinch, which is contradictory to what the pair found. Unless covered by a sleeve, a bare arm cannot form the proper seal against the nose necessary to obstruct airflow. A cough is then able to leak through any openings and propagate in many directions.

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Galactic bar paradox resolved in cosmic dance

 New light has been shed on a mysterious and long-standing conundrum at the very heart of our galaxy. The new work offers a potential solution to the so-called 'Galactic bar paradox', whereby different observations produce contradictory estimates of the motion of the central regions of the Milky Way. The results are published in Monthly Notices of the Royal Astronomical Society.

The majority of spiral galaxies, like our home the Milky Way, host a large bar-like structure of stars in their centre. Knowledge of the true bar size and rotational speed is crucial for understanding how galaxies form and evolve, as well as how they form similar bars throughout the Universe.

However our galaxy's bar size and rotational speed have been strongly contested in the last 5 years; while studies of the motions of stars near the Sun find a bar that is both fast and small, direct observations of the Galactic central region agree on one that is significantly slower and larger.

The new study, by an international team of scientists led by Tariq Hilmi of the University of Surrey and Ivan Minchev of the Leibniz Institute for Astrophysics Potsdam (AIP), suggests an insightful solution to this discrepancy. Analysing state-of-the-art galaxy formation simulations of the Milky Way, they show that both the bar's size and its rotational speed fluctuate rapidly in time, causing the bar to appear up to twice as long and rotate 20 percent faster at certain times.

The bar pulsations result from its regular encounters with the Galactic spiral arms, in what can be described as a "cosmic dance." As the bar and spiral arm approach each other, their mutual attraction due to gravity makes the bar slow down and the spiral speed up. Once connected, the two structures move as one and the bar appears much longer and slower than it actually is. As the dancers split apart, the bar speeds up while the spiral slows back down.

"The controversy about the Galactic bar can then be simply resolved if we happen to be living at a time when the bar and spiral are connected, giving the illusion of a large and slow bar," comments Dr Minchev. "However the motion of the stars near the Sun remains governed by the bar's true, much smaller nature, and so those observations appear contradictory."

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Ancient star explosions revealed in deep-sea sediments

 A mystery surrounding the space around our solar system is unfolding thanks to evidence of supernovae found in deep-sea sediments.

Professor Anton Wallner, a nuclear physicist at ANU, led the study which shows Earth has been travelling for the last 33,000 years through a cloud of faintly radioactive dust.

"These clouds could be remnants of previous supernova explosions, a powerful and super bright explosion of a star," Professor Wallner said.

Professor Wallner conducted the research at the ANU Heavy Ion Accelerator Facility (HIAF). He also holds joint positions at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Technical University Dresden (TUD) in Germany.

The researchers searched through several deep-sea sediments from two different locations that date back 33,000 years using the extreme sensitivity of HIAF's mass spectrometer. They found clear traces of the isotope iron-60, which is formed when stars die in supernova explosions.

Iron-60 is radioactive and completely decays away within 15 million years, which means any iron-60 found on Earth must have been formed much later than the rest of the 4.6-billion-year old earth and arrived here from nearby supernovae before settling on the ocean floor.

Professor Wallner previously found traces of iron-60 at about 2.6 million years ago, and possibly another at around 6 million years ago, suggesting earth had travelled through fallout clouds from nearby supernovae.

For the last few thousand years the solar system has been moving through a denser cloud of gas and dust, known as the local interstellar cloud, (LIC), whose origins are unclear. If this cloud had originated during the past few million years from a supernova, it would contain iron-60, and so the team decided to search more recent sediment to find out.

Sure enough, there was iron-60 in the sediment at extremely low levels -- equating to radioactivity levels in space far below Earth's natural background levels -- and the distribution of the iron-60 matched earth's recent travel through the local interstellar cloud. But the iron-60 extended further back and was spread throughout the entire 33,000 year measurement period.

The lack of correlation with the solar system's time in the current local interstellar cloud seems to pose more questions than it answers. Firstly, if the cloud was not formed by a supernova, where did it come from? And secondly, why is there iron-60 so evenly spread throughout space?

"There are recent papers that suggest iron-60 trapped in dust particles might bounce around in the interstellar medium," Professor Wallner said.

"So the iron-60 could originate from even older supernovae explosions, and what we measure is some kind of echo.

Read more at Science Daily

East Antarctic melting hotspot identified

 Ice is melting at a surprisingly fast rate underneath Shirase Glacier Tongue in East Antarctica due to the continuing influx of warm seawater into the Lützow-Holm Bay.

Hokkaido University scientists have identified an atypical hotspot of sub-glacier melting in East Antarctica. Their findings, published in the journal Nature Communications, could further understandings and predictions of sea level rise caused by mass loss of ice sheets from the southernmost continent.

The 58th Japanese Antarctic Research Expedition had a very rare opportunity to conduct ship-based observations near the tip of East Antarctic Shirase Glacier when large areas of heavy sea ice broke up, giving them access to the frozen Lützow-Holm Bay into which the glacier protrudes.

"Our data suggests that the ice directly beneath the Shirase Glacier Tongue is melting at a rate of 7-16 meters per year," says Assistant Professor Daisuke Hirano of Hokkaido University's Institute of Low Temperature Science. "This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf, which was thought to be experiencing the highest melting rate in East Antarctica, at a rate of 10-11 meters per year."

The Antarctic ice sheet, most of which is in East Antarctica, is Earth's largest freshwater reservoir. If it all melts, it could lead to a 60-meter rise in global sea levels. Current predictions estimate global sea levels will rise one meter by 2100 and more than 15 meters by 2500. Thus, it is very important for scientists to have a clear understanding of how Antarctic continental ice is melting, and to more accurately predict sea level fluctuations.

Most studies of ocean-ice interaction have been conducted on the ice shelves in West Antarctica. Ice shelves in East Antarctica have received much less attention, because it has been thought that the water cavities underneath most of them are cold, protecting them from melting.

During the research expedition, Daisuke Hirano and collaborators collected data on water temperature, salinity and oxygen levels from 31 points in the area between January and February 2017. They combined this information with data on the area's currents and wind, ice radar measurements, and computer modelling to understand ocean circulation underneath the Shirase Glacier Tongue at the glacier's inland base.

The scientists' data suggests the melting is occurring as a result of deep, warm water flowing inwards towards the base of the Shirase Glacier Tongue. The warm water moves along a deep underwater ocean trough and then flows upwards along the tongue's base, warming and melting the ice. The warm waters carrying the melted ice then flow outwards, mixing with the glacial meltwater.

The team found this melting occurs year-round, but is affected by easterly, alongshore winds that vary seasonally. When the winds diminish in the summer, the influx of the deep warm water increases, speeding up the melting rate.

Read more at Science Daily

Wireless device makes clean fuel from sunlight, CO2 and water

 Researchers have developed a standalone device that converts sunlight, carbon dioxide and water into a carbon-neutral fuel, without requiring any additional components or electricity.

The device, developed by a team from the University of Cambridge, is a significant step toward achieving artificial photosynthesis -- a process mimicking the ability of plants to convert sunlight into energy. It is based on an advanced 'photosheet' technology and converts sunlight, carbon dioxide and water into oxygen and formic acid -- a storable fuel that can be either be used directly or be converted into hydrogen.

The results, reported in the journal Nature Energy, represent a new method for the conversion of carbon dioxide into clean fuels. The wireless device could be scaled up and used on energy 'farms' similar to solar farms, producing clean fuel using sunlight and water.

Harvesting solar energy to convert carbon dioxide into fuel is a promising way to reduce carbon emissions and transition away from fossil fuels. However, it is challenging to produce these clean fuels without unwanted by-products.

"It's been difficult to achieve artificial photosynthesis with a high degree of selectivity, so that you're converting as much of the sunlight as possible into the fuel you want, rather than be left with a lot of waste," said first author Dr Qian Wang from Cambridge's Department of Chemistry.

"In addition, storage of gaseous fuels and separation of by-products can be complicated -- we want to get to the point where we can cleanly produce a liquid fuel that can also be easily stored and transported," said Professor Erwin Reisner, the paper's senior author.

In 2019, researchers from Reisner's group developed a solar reactor based on an 'artificial leaf' design, which also uses sunlight, carbon dioxide and water to produce a fuel, known as syngas. The new technology looks and behaves quite similarly to the artificial leaf but works in a different way and produces formic acid.

While the artificial leaf used components from solar cells, the new device doesn't require these components and relies solely on photocatalysts embedded on a sheet to produce a so-called photocatalyst sheet. The sheets are made up of semiconductor powders, which can be prepared in large quantities easily and cost-effectively.

In addition, this new technology is more robust and produces clean fuel that is easier to store and shows potential for producing fuel products at scale. The test unit is 20 square centimetres in size, but the researchers say that it should be relatively straightforward to scale it up to several square metres. In addition, the formic acid can be accumulated in solution, and be chemically converted into different types of fuel.

"We were surprised how well it worked in terms of its selectivity -- it produced almost no by-products," said Wang. "Sometimes things don't work as well as you expected, but this was a rare case where it actually worked better."

The carbon-dioxide converting cobalt-based catalyst is easy to make and relatively stable. While this technology will be easier to scale up than the artificial leaf, the efficiencies still need to be improved before any commercial deployment can be considered. The researchers are experimenting with a range of different catalysts to improve both stability and efficiency.

The current results were obtained in collaboration with the team of Professor Kazunari Domen from the University of Tokyo, a co-author of the study.

 Read more at Science Daily

How dinosaur research can help medicine

 The intervertebral discs connect the vertebrae and give the spine its mobility. The disc consists of a cartilaginous fibrous ring and a gelatinous core as a buffer. It has always been assumed that only humans and other mammals have discs. A misconception, as a research team under the leadership of the University of Bonn has now discovered: Even Tyrannosaurus rex could have suffered a slipped disc. The results have now been published in the journal "Scientific Reports."

Present-day snakes and other reptiles do not have intervertebral discs; instead, their vertebrae are connected with so-called ball-and-socket joints. Here, the ball-shaped end surface of a vertebra fits into a cup-shaped depression of the adjacent vertebra, similar to a human hip joint. In-between there is cartilage and synovial fluid to keep the joint mobile. This evolutionary construction is good for today's reptiles, because it prevents the dreaded slipped disc, which is caused by parts of the disc slipping out into the spinal canal.

"I found it hard to believe that ancient reptiles did not have intervertebral discs," says paleontologist Dr. Tanja Wintrich from the Section Paleontology in the Institute of Geosciences of the University of Bonn. She noticed that the vertebrae of most dinosaurs and ancient marine reptiles look very similar to those of humans -- that is, they do not have ball-and-socket joints. She therefore wondered whether extinct reptiles had intervertebral discs, but had "replaced" these with ball-and-socket joints in the course of evolution.

Comparison of the vertebrae of dinosaurs with animals still alive today

To this end, the team of researchers led by Tanja Wintrich and with the participation of the University of Cologne and the TU Bergakademie Freiberg as well as researchers from Canada and Russia examined a total of 19 different dinosaurs, other extinct reptiles, and animals still alive today. The researchers concluded that intervertebral discs not only occur in mammals. For these investigations, vertebrae still in connection were analyzed using various methods.

Surprisingly, Dr. Wintrich has now also been able to demonstrate that remnants of cartilage and even other parts of the intervertebral disc are almost always preserved in such ancient specimens, including marine reptiles like ichthyosaurs and dinosaurs like Tyrannosaurus. She then traced the evolution of the soft tissues between the vertebrae along the family tree of land animals, which 310 million years ago split into the mammalian line and the dinosaur and bird line.

Intervertebral discs emerged several times during evolution

It was previously unknown that intervertebral discs are a very ancient feature. The findings also show that intervertebral discs evolved several times during evolution in different animals, and were probably replaced by ball-and-socket joints twice in reptiles. "The reason why the intervertebral disc was replaced might be that it is more susceptible to damage than a ball-and-socket joint," says Dr. Wintrich. Nonetheless, mammals have always retained intervertebral discs, repeating the familiar pattern that they are rather limited in their evolutionary flexibility. "This insight is also central to the medical understanding of humans. The human body is not perfect, and its diseases reflect our long evolutionary history," adds paleontologist Prof. Dr. Martin Sander from the University of Bonn.

In terms of research methods, the team drew not only on paleontology, but also on medical anatomy, developmental biology and zoology. Under the microscope, dinosaur bones cut with a rock saw and then ground very thinly provide information comparable to histological sections of fixed and embedded tissue of extant animals. This makes it possible to bridge the long periods of evolution and identify developmental processes. Prof. Sander remarks: "It's truly amazing that the cartilage of the joint and apparently even the disc itself can survive for hundreds of millions of years."

Dr. Wintrich, who now works at the Institute of Anatomy of the University of Bonn, is pleased about the cooperation between the fields that has made this interdisciplinary understanding possible in the first place: "We found that even Tyrannosaurus rex was not protected against slipped discs." Only bird-like predatory dinosaurs then evolved ball-and-socket joints as well and saddle joints, still seen in today's birds. Likewise, such ball-and-socket joints were a decisive advantage for the stability of the spine of the largest dinosaurs, the long-necked dinosaurs.

Read more at Science Daily

Antibodies that may protect against COVID-19

 A new study by researchers at MassBiologics of UMass Medical School published in Nature Communications suggests that COVID specific IgA monoclonal antibodies may provide effective immunity in the respiratory system against the novel coronavirus -- a potentially critical feature of an effective vaccine.

Yang Wang, MD, PhD, deputy director for product discovery at MassBiologics and associate professor of medicine, and colleagues describe the discovery and characterization of a cross-reactive human monoclonal antibody (MAB) to SARS-CoV-2 spike proteins which blocks ACE2 receptor binding on the mucosal tissue of the respiratory tract -- potentially preventing or limiting SARS-CoV-2 infection causing COVID-19 disease.

Like scientists around the world, the research leadership at MassBiologics started talking about what became known as SARS-CoV-2 within days of the first cases of when the novel coronavirus were first reported. MassBiologics was in a unique position to respond, and those early discussions have resulted in the discovery of a novel approach to prevent and treat SARS-CoV-2 infection.

The origins of this rapid and important discovery go back 16 years, when MassBiologics developed an IgG monoclonal antibody that was effective against a similar virus, SARS (that was SARS-CoV, the first severe acute respiratory syndrome caused by a novel coronavirus). That first SARS virus caused alarming illness, but then disappeared; MassBiologics, which was ready at the time to initiate a clinical trial, saved the research materials associated with that work.

When SARS-CoV-2 was recognized and began to spread, MassBiologics researchers realized that that first MAB might help with this new infection. They launched the process of resurrecting the old SARS program, retrieving frozen hybridoma cells that had been developed 16 years earlier, thawing them and determining if what worked for one novel coronavirus would work for another. Although there was 90 percent similarity between the two coronaviruses, the monoclonal antibody exhibited no binding to the current coronavirus. MassBiologics then evaluated another MAB from that earlier work, which was also only weakly effective.

Undeterred, Wang and colleagues thought about their experience with a separate research program to develop "secretory IgAs (sIgA)," antibodies that play a crucial role in immunity on mucosal surfaces. MassBiologics has been investigating sIgA in the GI tract as a possible therapeutic to prevent gastrointestinal infections. Would similar anti-SARS-CoV-2 sIgA produce passive mucosal immunity in the respiratory tract, where COVID-19 disease is incredibly damaging? The approach worked, producing an antibody with binding affinity and neutralization activity. This antibody was designated MAb362.

"We were excited to learn that antibodies to SARS-CoV-2 are more effective in binding to and neutralizing the virus when they are in the sIgA isotype of antibody, compared to the usual circulating IgG antibodies," said Mark Klempner, MD, executive vice chancellor for MassBiologics and professor of medicine. "In nature, sIgA antibodies coat mucosal surfaces like the respiratory, GI and GU tracts, where they are stabilized by the mucous layer on these surfaces. There, they perform the important function of preventing binding of a pathogen to host cells, thus preventing infection."

Based on these results, MassBiologics worked with Celia Schiffer, PhD, the Gladys Smith Martin Chair in Oncology, professor of biochemistry & molecular pharmacology, and director of the Institute for Drug Resistance, and her then-graduate student, Shurong Hou, who has since completed her studies and earned her PhD, to see if they could understand the nature of the effect of the IgA antibody. Drs. Schiffer and Hou found MAb362 shared a highly similar framework with MAb 80R, another SARS-CoV antibody with a crystal structure in complex with SARS-CoV. A molecular model revealed a highly conserved protective epitope within the receptor-binding domain of the S protein. MAb362 neutralizes authentic SARS-CoV-2 virus by directly out-competing the S protein's binding to hACE2 receptors.

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Nasal vaccine against COVID-19 prevents infection in mice

 Scientists at Washington University School of Medicine in St. Louis have developed a vaccine that targets the SARS-CoV-2 virus, can be given in one dose via the nose and is effective in preventing infection in mice susceptible to the novel coronavirus. The investigators next plan to test the vaccine in nonhuman primates and humans to see if it is safe and effective in preventing COVID-19 infection.

The study is available online in the journal Cell.

Unlike other COVID-19 vaccines in development, this one is delivered via the nose, often the initial site of infection. In the new study, the researchers found that the nasal delivery route created a strong immune response throughout the body, but it was particularly effective in the nose and respiratory tract, preventing the infection from taking hold in the body.

"We were happily surprised to see a strong immune response in the cells of the inner lining of the nose and upper airway -- and a profound protection from infection with this virus," said senior author Michael S. Diamond, MD, PhD, the Herbert S. Gasser Professor of Medicine and a professor of molecular microbiology, and of pathology and immunology. "These mice were well protected from disease. And in some of the mice, we saw evidence of sterilizing immunity, where there is no sign of infection whatsoever after the mouse is challenged with the virus."

To develop the vaccine, the researchers inserted the virus' spike protein, which coronavirus uses to invade cells, inside another virus -- called an adenovirus -- that causes the common cold. But the scientists tweaked the adenovirus, rendering it unable to cause illness. The harmless adenovirus carries the spike protein into the nose, enabling the body to mount an immune defense against the SARS-CoV-2 virus without becoming sick. In another innovation beyond nasal delivery, the new vaccine incorporates two mutations into the spike protein that stabilize it in a specific shape that is most conducive to forming antibodies against it.

"Adenoviruses are the basis for many investigational vaccines for COVID-19 and other infectious diseases, such as Ebola virus and tuberculosis, and they have good safety and efficacy records, but not much research has been done with nasal delivery of these vaccines," said co-senior author David T. Curiel, MD, PhD, the Distinguished Professor of Radiation Oncology. "All of the other adenovirus vaccines in development for COVID-19 are delivered by injection into the arm or thigh muscle. The nose is a novel route, so our results are surprising and promising. It's also important that a single dose produced such a robust immune response. Vaccines that require two doses for full protection are less effective because some people, for various reasons, never receive the second dose."

Although there is an influenza vaccine called FluMist that is delivered through the nose, it uses a weakened form of the live influenza virus and can't be administered to certain groups, including those whose immune systems are compromised by illnesses such as cancer, HIV and diabetes. In contrast, the new COVID-19 intranasal vaccine in this study does not use a live virus capable of replication, presumably making it safer.

The researchers compared this vaccine administered to the mice in two ways -- in the nose and through intramuscular injection. While the injection induced an immune response that prevented pneumonia, it did not prevent infection in the nose and lungs. Such a vaccine might reduce the severity of COVID-19, but it would not totally block infection or prevent infected individuals from spreading the virus. In contrast, the nasal delivery route prevented infection in both the upper and lower respiratory tract -- the nose and lungs -- suggesting that vaccinated individuals would not spread the virus or develop infections elsewhere in the body.

The researchers said the study is promising but cautioned that the vaccine so far has only been studied in mice.

"We will soon begin a study to test this intranasal vaccine in nonhuman primates with a plan to move into human clinical trials as quickly as we can," Diamond said. "We're optimistic, but this needs to continue going through the proper evaluation pipelines. In these mouse models, the vaccine is highly protective. We're looking forward to beginning the next round of studies and ultimately testing it in people to see if we can induce the type of protective immunity that we think not only will prevent infection but also curb pandemic transmission of this virus."

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Why babies don't always remember what they have learned

 If and how babies recall what they have learned depends on their mood: what they've learned when feeling calm is inaccessible when they're acitive and vice versa. This was shown in a study conducted by developmental psychologists at Ruhr-Universität Bochum (RUB) with 96 children aged nine months. They published their report in the journal Child Development from 19. August 2020.

One minute happy, next minute sad

The mood of infants is unpredictable: they may be playing happily one moment and be completely inconsolable the next. "Surprisingly, it hadn't yet been understood whether these changes in mood affect learning and memory in babies," says Professor Sabine Seehagen, Head of the Developmental Psychology research group at RUB. Studies with adults have shown that moods affect thinking. We remember experiences that we had in a certain mood, especially when we are in the same mood again.

In order to find out whether this phenomenon, which is known as state-dependent memory, also exists in babies, the researchers studied 96 children aged nine months. In the first step, the babies either performed quiet activities with their parent, such as looking at picture books, or they went wild by hopping around; then, they watched an experimenter performing actions with a hand puppet, thus learning how to do this. "The aspect that interested us was whether or not the children were able to imitate the observed actions a quarter of an hour later," as Sabine Seehagen outlines the experiment. Just before the test started, some of the babies were put into the same state as when they were learning, while others were put into a different mood by playing the opposite games.

Access to memory content blocked

The infants who had been in a different mood when learning than when recalling what they'd learned could not imitate the actions with the puppet: the memory performance was two and a half times higher if they were in the same mood when learning and when recalling what they'd learned. "This shows that fluctuations in internal state at this age can prevent access to memory content," points out Seehagen.

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