HR 8799 super-Jupiters’ days measured for the first time, gives a new spin on unraveling planet formation mystery

Astronomers have captured the first-ever spin measurements of HR 8799, the famed system that made history as the very first exoplanetary system to have its image taken.

Discovered in 2008 by two Maunakea Observatories in Hawaii -- W. M. Keck Observatory and the international Gemini Observatory, a Program of NSF's NOIRLab -- the HR 8799 star system is located 129 light-years away and has four planets more massive than Jupiter, or super-Jupiters: HR 8799 planets b, c, d, and e. None of their rotation periods had ever been measured, until now.

The breakthrough was made possible by a Caltech and Keck Observatory-led science and engineering team that has developed an instrument capable of observing known imaged exoplanets at spectral resolutions that are detailed enough to allow astronomers to decipher how fast the planets are spinning.

Using the state-of-the-art Keck Planet Imager and Characterizer (KPIC) on the Keck II telescope atop Hawaii Island's Maunakea, astronomers found that the minimum rotation speeds of HR 8799 planets d and e clocked in at 10.1 km/s and 15 km/s, respectively. This translates to a length of day that could be as short as three hours or could be up to 24 hours such as on Earth depending on the axial tilts of the HR 8799 planets, which are currently undetermined. For context, one day on Jupiter lasts nearly 10 hours; its rotation speed is about 12.7 km/s.

As for the other two planets, the team was able to constrain the spin of HR 8799 c to an upper limit of less than 14 km/s; planet b's rotation measurement was inconclusive.

The findings are KPIC's first science results, which have been accepted for publication in The Astronomical Journal.

"With KPIC, we were able to obtain the highest spectral resolution observations ever conducted of the HR 8799 exoplanets," says Jason Wang, an astronomer at Caltech and lead author of the study. "This allows us to study them with finer granularity than ever before and unlocks the key to gaining a deeper understanding of not just how these four planets formed, but how gas giants in general develop throughout the universe."

DIZZY DATA UNVEILS PLANETS' PAST

How fast a planet spins gives insight into its formation history. Created out of gas and dust kicked up by a newborn star, baby planets start spinning faster as they accumulate more material and grow -- a process called core accretion. It is believed that planetary magnetic fields then slow and cap their rotation speed. After the fully-formed planet is finished accreting and cools off, it spins back up.

"The spins of HR 8799 planets d and e are consistent with the theory that the planets' magnetic fields put a brake on their spins in their natal years," says Wang. "The spin measurements also hint at the notion that lower mass planets spin faster because they are less affected by magnetic braking, which might tell us something important about how they form. I find this tantalizing."

Wang stresses this possible trend is unconfirmed; to validate it requires more KPIC spin measurements of lower mass companions. The team's goal is to find a common link between the rotation periods of the HR 8799 planets, the giant planets in our own solar system, Jupiter and Saturn, and other known super-Jupiters and brown dwarfs.

"With enough spin measurements, we'll be able to identify trends that would reveal how the physical processes driving planet formation work," says co-author Jean-Baptiste Ruffio, a David and Ellen Lee Postdoctoral Scholar Research Associate in Astronomy at Caltech. "This is something that people have already started doing, but KPIC is allowing us to do this for the smallest, faintest, and closest imaged alien worlds."

KPIC'S FIRST LIGHT SUCCESS

Commissioned between 2018 to 2020, KPIC's specialty is detecting exoplanets and brown dwarfs that orbit so close to their host stars that the glare from the starlight makes it difficult to 'see' these celestial bodies from Earth. The instrument filters unwanted starlight by way of an innovative fiber injection unit that routes light from the Keck II telescope adaptive optics (AO) system into the Observatory's Near-Infrared Spectrograph (NIRSPEC).

KPIC's first light results are outlined in a technical paper that has been accepted in the Journal of Astronomical Telescopes, Instruments, and Systems (JATIS).

"KPIC is a game-changer in the field of exoplanet characterization," says KPIC Principal Investigator Dimitri Mawet, Professor of Astronomy at Caltech. "It allows us to measure a planet's length of day, orbit, and molecular makeup of its atmosphere."

KPIC made strong detections of water and carbon monoxide, but no methane, in three of the four HR 8799 planets -- c, d, and e -- which is consistent with what is known of the planets' atmospheres.

"It's exciting to see KPIC's superpower manifest," says Keck Observatory AO Scientist/Engineer Jacques Delorme, lead author of the JATIS paper. "Because this is the first technology of its kind, we didn't know if KPIC was going to work as well as it did. Now that we have successfully demonstrated its capabilities, we can move on to Phase 2 of the project to further improve the instrument's overall performance."

"We have yet to unlock KPIC's full science potential," says Caltech Lead Instrument Scientist Nemanja Jovanovic, co-author of the technical paper. "Through more instrument upgrades, we hope to observe exoplanets in the near future with such a high degree of detail, that we'll be able to study weather phenomena and map clouds of gas giant planets."

Read more at Science Daily

Astronomers discover how to feed a black hole

The black holes at the centres of galaxies are the most mysterious objects in the Universe, not only because of the huge quantities of material within them, millions of times the mass of the Sun, but because of the incredibly dense concentration of matter in a volume no bigger than that of our Solar System. When they capture matter from their surroundings they become active, and can send out enormous quantities of energy from the capture process, although it is not easy to detect the black hole during these capture episodes, which are not frequent.

However, a study led by the researcher Almudena Prieto, of the Instituto de Astrofísica de Canarias (IAC), has discovered long narrow dust filaments which surround and feed these black holes in the centres of galaxies, and which could be the natural cause of the darkening of the centres of many galaxies when their nuclear black holes are active. The results of this study have recently been published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS).

Using images from the Hubble Space Telescope, the Very Large Telescope (VLT) at the European Southern Observatory (ESO), and the Atacama Large Millimetre Array (ALMA) in Chile, the scientists have been able to obtain a direct visualization of the process of nuclear feeding of a black hole in the galaxy NGC 1566 by these filaments. The combined images show a snapshot in which one can see how the dust filaments separate, and then go directly towards the centre of the galaxy, where they circulate and rotate in a spiral around the black hole before being swallowed by it.

"This group of telescopes has given us a completely new perspective of a supermassive black hole, thanks to the imaging at high angular resolution and the panoramic visualization of its surroundings, because it lets us follow the disappearance of the dust filaments as they fall into the black hole," explains Almudena Prieto, the first author on the paper.

The study is the result of the long-term PARSEC project of the IAC, which aims to understand how supermassive black holes wake up from their long lives of hibernation, and after a process in which they accrete material from their surroundings, they become the most powerful objects in the Universe.

Read more at Science Daily

Older adults are happier when space matches personality

The old saying, "Home is where the heart is," has some new science to back it up. A study has found photos of a person's living space can accurately point at personality traits and the mood of the people who live there, especially as a person gets older.

For the study, scientists at The University of Texas at Austin studied 286 people over the age of 65. They took photographs of the rooms where the subjects spent the most time (typically the living room) and found that certain characteristics of a person's personality were reflected in core elements of room décor. Applying the findings could help lead to happier lives, including for older adults with frailty or cognitive impairment that has led them to be transferred from their homes to long-term care facilities.

"People who have a match between personality and living space report better well-being, and they feel better about their life and have a better mood," said Karen Fingerman, professor of human development and family sciences at The University of Texas at Austin and director of the Texas Aging and Longevity Center. "Home is where we can express ourselves."

The researchers analyzed participants' personalities and took photos of the room where each person spent the most time. As part of a first-of-its-kind study, independent examiners looked at the photos and rated characteristics of the room, such as brightness, cleanliness and newness. The results were published online in the journal The Gerontologist earlier this month.

Extraversion was expressed in room décor with newness of items in the room and cheerfulness of décor. This may come from a desire to make the room appealing to visiting friends and family, researchers said.

Conscientiousness was associated with newness and comfort. Because orderliness and organization are key components of that personality trait, that may explain the association.

Agreeableness, openness and neuroticism were not associated with room décor for everyone, scientists found. But openness was evident in the décor for older adults who live alone, suggesting that people who live with others may not have as much latitude to express their personalities in their room décor.

Importantly, when a living space matches the personality and preferences of the person who lives there, older adults reported enhanced well-being.

The goal for many older adults is to grow older in their own homes, but as they encountered functional limitations, such as not being able to walk or climb stairs, their homes became out-of-date, uncomfortable, dim and cluttered. Scientists said this may be because those adults have less energy to maintain their spaces.

Surprisingly, for adults with functional limitations, clutter was associated with fewer symptoms of depression.

"Clutter may represent an effort to exert control over the environment," Fingerman said. "They may also wish to keep items close at hand to compensate for mobility issues."

Researchers said this study suggests that older adults with functional limitations may benefit from a little help around the house, but cleaning and maintenance should be done in collaboration. What looks like clutter to one person may be an arrangement that makes an older adult more comfortable.

Long-term care facilities that allow for greater latitude in room décor to improve the mood of residents also may see benefits.

"There is no one ideal way to create a living space," Fingerman said. "It has to match the person."

Read more at Science Daily

Researchers film human viruses in liquid droplets at near-atomic detail

A pond in summer can reveal more about a fish than a pond in winter. The fish living in icy conditions might remain still enough to study its scales, but to understand how the fish swims and behaves, it needs to freely move in three dimensions. The same holds true for analyzing how biological items, such as viruses, move in the human body, according to a research team led by Deb Kelly, Huck Chair in Molecular Biophysics and professor of biomedical engineering at Penn State, who has used advanced electron microscopy (EM) technology to see how human viruses move in high resolution in a near-native environment. The visualization technique could lead to improved understanding of how vaccine candidates and treatments behave and function as they interact with target cells, Kelly said.

In an effort to expand the tools scientists have to study the microscopic world, researchers recorded live, 20-second-long movies of human viruses floating in liquid at near-atomic detail in an electron microscope. The same degree of information, immediately available as they record, may take up to 24 hours to acquire using traditional static imaging methods. Their approach and results were made available online July 24 in Advanced Materials.

"The challenge remained to view biological materials in dynamic systems that reflects their authentic performance in the body," said Kelly, who also directs the Penn State Center for Structural Oncology. "Our results show new structures and active insights of human viruses contained in minute volumes of liquid -- the same size as respiratory droplets that spread SARS-CoV-2."

Cryogenic electron microscopy (cryo-EM) is becoming the field's gold standard for observing samples at or beyond atomic resolution, according to Kelly. The technique involves flash freezing the sample and focusing a beam of electrons through it. The electrons and the sample's components interact, which is captured by detectors embedded in the instrument. Thousands of images can be processed to calculate what the item looks like in 3D -- but more is needed to fully understand how the item functions in a more natural setting.

"While cryo-EM can tell us a lot of information, it still produces a static image," said GM Jonaid, the paper's first author and a student in the Bioinformatics and Genomics Graduate Program in the Huck Institutes of the Life Sciences. Jonaid is conducting his doctoral dissertation research in Kelly's lab. "With improved chips and a powerful direct detector on the microscope, we can accumulate a lot of movie frames to view how the sample acts in real time. We can see things how they exist -- not just how we prepared them."

The researchers used adeno-associated virus (AAV) as a model system to demonstrate their approach. AAV is a biological nanoparticle that can be used to help deliver vaccines or treatments directly to cells. The platform is based on a hijacked adenovirus, which can easily enter several kinds of cells. The ease with which it interacts with cells makes it a useful capsule to transport its engineered payload.

"AAV is a well-known, gene therapy vehicle with current applications involved in drug delivery and vaccine development for COVID-19," Kelly said. "This model system is already well-studied so we can use it to validate our approach with the goal of seeing biological entitles in a liquid state, as maintained in the human body."

The researchers applied minute volumes of liquid solution containing AAV to the wells of specialized silicon nitride microchips, commercially supplied by Protochips Inc. They then placed the microchip assemblies in the EM to examine the viruses in action.

"The images are very comparable to cryo-EM data, but the preparation was less complex, less technically involved," Jonaid said. "Once we had the images, taken rapidly, like frames of a movie, we processed them just like we would any other high-resolution data."

The results were videos of AAV moving in liquid, with subtle changes in the particle's surface, suggesting that the particle's physical properties change as it explores its environment, Kelly said. The resolution was close to three to four Angstroms (a single atom is measured as one Angstrom).

Once they proved the imaging strategies worked, the researchers set their sights on a smaller target: antibodies produced by COVID-19 patients.

"We saw how antibodies contained in the serum of COVID-19 patients interacted with the remaining SARS-CoV-2 particles," Kelly said, noting that the ability to observe such interactions would be especially useful when assessing the viability of vaccine candidates prior to clinical trials.

Kelly and her team plan to continue investigating the molecular underpinnings of SARS-CoV-2 and host-receptor proteins using liquid phase-EM, as a complement to the information garnered from cryo-EM results.

"You really need data from both techniques to understand how viruses look and behave in the living body," Kelly said. "Visualizing the dynamic movement in solution complements high-resolution snapshots to reveal more complete information."

Read more at Science Daily

Clever cockatoos learn through social interaction, study finds

For the first time, a team of international scientists have proven that cockatoos, an iconic Australian bird species, learn from each other a unique skill -- lifting garbage bin lids to gather food. The world-first research published today in Science, confirms that cockatoos spread this novel behavior through social learning. Led by Barbara Klump and Lucy Aplin (Max Planck Institute of Animal Behavior), along with John Martin (Taronga Conservation Society) and Richard Major (Australian Museum), the team have shown that this behavior by cockatoos is actually learnt, rather than a result of genetics.

Lead co-author, Barbara Klump, said social learning is the basis of different regional cultures, and some animals, such as primates and birds, appear to learn socially. "Children are masters of social learning. From an early age, they copy skills from other children and adults. However, compared to humans, there are few known examples of animals learning from each other," Klump said.

"Demonstrating that food scavenging behavior is not due to genetics is a challenge," Klump added.

However, a few years ago, Richard Major shared a video with senior author Lucy Aplin, showing a sulphur-crested cockatoo opening a closed garbage bin. The cockatoo used its beak and foot to lift the heavy lid then shuffled along the side to flip it over, accessing a rich reward of leftover food.

Aplin, who was then researching at Oxford University and has since moved to the Max Planck Institute of Animal Behavior in Germany, and Klump were fascinated by the footage.

"It was so exciting to observe such an ingenious and innovative way to access a food resource, we knew immediately that we had to systematically study this unique foraging behavior," Klump said.

Major, a Senior Principal Research Scientist at the Australian Museum Research Institute, has spent more than 20 years studying Australian bird species such as the noisy minor, the infamous 'bin-chicken' ibis and cockatoos.

"Like many Australian birds, sulphur-crested cockatoos are loud and aggressive and often act like a pack of galahs. But they are also incredibly smart, persistent and have adapted brilliantly to living with humans," Major said.

John Martin a Research Scientist at Taronga Conservation Society, who has worked alongside Major on many urban bird projects, explained how the research was conducted. "Australian garbage bins have a uniform design across the country, and sulphur-crested cockatoos are common across the entire east coast. The first thing we wanted to find out is if cockatoos open bins everywhere."

"In 2018, we launched an online survey in various areas across Sydney and Australia with questions such as, 'What area are you from, have you seen this behavior before, and if so, when?' The survey ran for two years and helped us determine how the behavior spread to other cockatoos in Sydney. Importantly we'll be continuing this survey in 2021," Martin said.

By the end of 2019, residents from 44 areas had observed the bin-opening behavior, showing that it had spread rapidly and widely. Further analysis of the survey results showed that the behavior reached neighboring districts more quickly than districts further away, indicating that the new behavior wasn't popping up randomly across Sydney.

"These results show the animals really learned the behavior from other cockatoos in their vicinity," Klump said.

The researchers also marked around 500 cockatoos with small paint dots at three selected hot spots to enable the identification of individual birds, allowing the researchers to observe which birds could open bins. It turned out that only around ten percent could do so, most of which were males. The rest waited until the "pioneers" opened the garbage bins to then help themselves.

There was one exception, however: in late 2018, a cockatoo in northern Sydney reinvented the scavenging technique itself. Birds in neighboring districts then copied the behavior.

"We observed that the birds do not open the garbage bins in the same way, but rather used different opening techniques in different suburbs, suggesting that the behavior is learned by observing others," Klump said.

The scientists interpreted the results as an emergence of regional subcultures.

The scientists hope that their findings will also generate a broader understanding of urban living animals.

"By studying this behavior with the help of local residents, we are uncovering the unique and complex cultures of their neighborhood birds," Klump said.

Read more at Science Daily

Magnetic fields implicated in the mysterious midlife crisis of stars

Middle-aged stars can experience their own kind of midlife crisis, experiencing dramatic breaks in their activity and rotation rates at about the same age as our Sun, according to new research published today in Monthly Notices of the Royal Astronomical Society: Letters. The study provides a new theoretical underpinning for the unexplained breakdown of established techniques for measuring ages of stars past their middle age, and the transition of solar-like stars to a magnetically inactive future.

Astronomers have long known that stars experience a process known as 'magnetic braking': a steady stream of charged particles, known as the solar wind, escapes from the star over time, carrying away small amounts of the star's angular momentum. This slow drain causes stars like our Sun to gradually slow down their rotation over billions of years.

In turn, the slower rotation leads to altered magnetic fields and less stellar activity -- the numbers of sunspots, flares, outbursts, and similar phenomena in the atmospheres of stars, which are intrinsically linked to the strengths of their magnetic fields.

This decrease in activity and rotation rate over time is expected to be smooth and predictable because of the gradual loss of angular momentum. The idea gave birth to the tool known as 'stellar gyrochronology', which has been widely used over the past two decades to estimate the age of a star from its rotation period.

However recent observations indicate that this intimate relationship breaks down around middle age. The new work, carried out by Bindesh Tripathi, Prof. Dibyendu Nandy, and Prof. Soumitro Banerjee at the Indian Institute of Science Education and Research (IISER) Kolkata, India, provides a novel explanation for this mysterious ailment.

Using dynamo models of magnetic field generation in stars, the team show that at about the age of the Sun the magnetic field generation mechanism of stars suddenly becomes sub-critical or less efficient. This allows stars to exist in two distinct activity states -- a low activity mode and an active mode. A middle aged star like the Sun can often switch to the low activity mode resulting in drastically reduced angular momentum losses by magnetized stellar winds.

Prof. Nandy comments: "This hypothesis of sub-critical magnetic dynamos of solar-like stars provides a self-consistent, unifying physical basis for a diversity of solar-stellar phenomena, such as why stars beyond their midlife do not spin down as fast as in their youth, the breakdown of stellar gyrochronology relations, and recent findings suggesting that the Sun may be transitioning to a magnetically inactive future."

The new work provides key insights into the existence of low activity episodes in the recent history of the Sun known as grand minima -- when hardly any sunspots are seen. The best known of these is perhaps the Maunder Minimum around 1645 to 1715, when very few sunspots were observed.

Read more at Science Daily

Biomedical scientists tie improved learning processes to reduced symptoms of depression

Virginia Tech scientists with the Fralin Biomedical Research Institute at VTC have identified neural learning processes to be associated with symptoms of depression and linked improvements in these processes to improved symptoms in research participants being treated for depression.

The findings, described in a study published July 28, 2021 in the Journal of the American Medical Association (JAMA) Psychiatry, suggest distinct paths to depression symptoms and new mathematically guided approaches for treating clinical depression.

Major depression is one of the most common mental disorders in the United States and can cause severe impairment, according to the National Institute of Mental Health. An estimated 7.1% of all U.S. adults have had at least one major depressive episode.

"Current medications and behavioral therapies are helpful, but for many people struggling with depression, existing treatments don't work well," said Pearl Chiu, an associate professor at the Fralin Biomedical Research Institute Computational Psychiatry Unit and the study's corresponding author. "We need to consider other possible paths to depression. These paths, or mechanisms, could point to new treatment targets to explore."

The scientists used computational models of brain functioning as a new way to consider mechanisms of depression. In a key discovery, the researchers found that the symptom improvements that followed cognitive behavioral therapy were related to improvements in reinforcement learning components that were disrupted prior to therapy.

"Depression is a very serious illness and a leading cause of disability in the world. We hope that our work can be a bridge between behavioral clinicians and computational scientists to more precisely identify what causes depression and new ways to treat the illness," said first author Vanessa Brown, a former doctoral student with Chiu in Virginia Tech's Department of Psychology and who is now an assistant professor of psychiatry at the University of Pittsburgh.

The research team began studying a baseline group of 101 adults with and without clinical depression. A subset of the participants with depression were treated with up to 12 weeks of cognitive behavioral therapy -- a treatment that involves learning how to identify and correct negative thought patterns.

Participants with depression played a learning game during functional MRI brain scanning before and after cognitive behavioral therapy, and participants without depression played the same game at time points matched to participants who took part in cognitive behavioral therapy. The scientists used computational modeling to identify different processes that contribute to learning. They found that distinct components of learning about rewards and losses -- known as reinforcement learning -- were connected to certain symptoms of depression.

"Two of the most exciting parts of the findings are that people with depression learn in different ways and that these learning processes changed when depression symptoms improved after cognitive behavioral therapy. The link between the learning components and symptoms is critical," said Brooks King-Casas, co-author of the study and an associate professor with the Fralin Biomedical Research Institute and in the Department of Psychology in Virginia Tech's College of Science.

The researchers say using computational models has potential to help other investigators and mental health professionals precisely identify new contributors to depression, which in turn could be new targets for therapies.

"An example is that for someone with depression, losing a few cents in the game could feel like losing several hundred dollars or the loss could be very hard to forget. These processes are different, but both affect how we learn and the choices we make," King-Casas said.

"We quantified some of these learning processes with computational modeling and show that they relate to depression in very different ways," said Chiu, who is also an associate professor of psychology in Virginia Tech's College of Science. "The idea is similar to how stress or too much sodium can both contribute to high blood pressure, but what contributes to a particular person's hypertension could suggest whether they focus on decreasing stress or reducing salt consumption as part of treatment. Similarly, for depression, the parts of learning that contribute to a person's depression could call for different approaches to treatment."

Chiu says forming a computational understanding of how cognitive processes align with symptoms of depression is a promising approach.

"Now that we've linked specific components of learning to depression and show that they change with specific depression symptoms, perhaps we can develop new therapies that focus on adjusting these learning components as a way to reduce depression," she said.

Read more at Science Daily

Does testosterone influence success? Not much, research suggests

With the Olympics underway, higher testosterone has often been linked to sporting success, and other kinds of success too. But beyond sport, new research has found little evidence that testosterone meaningfully influences life chances for men or women. In fact, the study suggests that despite the social myths surrounding testosterone, it could be much less important than previously thought.

It is already known that in men testosterone is linked with socioeconomic position, such as income or educational qualifications. Researchers from the University of Bristol's Population Health Sciences (PHS) and MRC Integrated Epidemiology Unit (IEU) wanted to find out whether this is because testosterone actually affects socioeconomic position, as opposed to socioeconomic circumstances affecting testosterone, or health affecting both. The findings are published today [28 July] in Science Advances.

To isolate effects of testosterone itself, the research team applied an approach called Mendelian randomization in a sample of 306,248 UK adults from UK Biobank. They explored testosterone's influence on socioeconomic position, including income, employment status, neighbourhood-level deprivation, and educational qualifications; on health, including self-rated health and BMI, and on risk-taking behaviour.

Dr Amanda Hughes, Senior Research Associate in Epidemiology in Bristol Medical School: Population Health Sciences (PHS), said: "There's a widespread belief that a person's testosterone can affect where they end up in life. Our results suggest that, despite a lot of mythology surrounding testosterone, its social implications may have been over-stated."

First, the team identified genetic variants linked to higher testosterone levels and then investigated how these variants were related to the outcomes. A person's genetic code is determined before birth, and generally does not change during their lifetime (there are rare exceptions, such as changes that occur with cancer). This makes it very unlikely that these variants are affected by socioeconomic circumstances, health, or other environmental factors during a person's lifetime. Consequently, any association of an outcome with variants linked to testosterone would strongly suggest an influence of testosterone on the outcome.

Similar to previous studies the research found that men with higher testosterone had higher household income, lived in less deprived areas, and were more likely to have a university degree and a skilled job. In women, higher testosterone was linked to lower socioeconomic position, including lower household income, living in a more deprived area, and lower chance of having a university degree. Consistent with previous evidence, higher testosterone was associated with better health for men and poorer health for women, and greater risk-taking behaviour for men.

In contrast, there was little evidence that the testosterone-linked genetic variants were associated with any outcome for men or women. The research team concluded that there is little evidence that testosterone meaningfully affected socioeconomic position, health, or risk-taking in men or women. The study suggests that -- despite the mythology surrounding testosterone -- it might be much less important than previously claimed.

Results for women were less precise than results for men, so the influence of testosterone in women could be studied in more detail in the future using larger samples.

Dr Hughes added: "Higher testosterone in men has previously been linked to various kinds of social success. A study of male executives found that testosterone was higher for those who had more subordinates. A study of male financial traders found that higher testosterone correlated with greater daily profits. Other studies have reported that testosterone is higher for more highly educated men, and among self-employed men, suggesting a link with entrepreneurship.

"Such research has supported the widespread idea that testosterone can influence success by affecting behaviour. There is evidence from experiments that testosterone can make a person more assertive or more likely to take risks -- traits which can be rewarded in the labour market, for instance during wage negotiations. But there are other explanations. For example, a link between higher testosterone and success might simply reflect an influence of good health on both. Alternatively, socioeconomic circumstances could affect testosterone levels. A person's perception of their own success could influence testosterone: in studies of sports matches, testosterone has been found to rise in the winner compared to the loser."

Read more at Science Daily

We are more forgiving when people close to us misbehave

When people behave badly or unethically, their loved ones may judge them less harshly than they would judge a stranger who committed the same transgressions, but that leniency may come at the cost of the judger's own sense of self-worth, according to research published by the American Psychological Association.

"How do we react when our romantic partners, friends or family members behave unethically? Past research tells us a lot about how we respond to a stranger's unethical behavior, but very little about how we respond when the perpetrator is someone we care deeply about," said lead author Rachel Forbes, MA, a PhD candidate at the University of Toronto. "When someone close to us behaves unethically, we face a conflict between upholding our moral values and maintaining our relationship. We conducted this research to better understand this conflict." The study was published in the Journal of Personality and Social Psychology.

Researchers conducted a series of four experiments involving more than 1,100 participants. In one experiment, participants read about a hypothetical situation in which a romantic partner, a close friend or a stranger committed an unethical or immoral act, such as stealing money from a charity collection jar. In another experiment, participants were asked to recall a moment when they had witnessed a romantic partner, close friend or stranger commit an unethical or immoral act. In a third experiment, participants kept a log of moral transgressions they witnessed each day for 15 days. In each experiment participants answered a series of questions about the person who committed the act, the severity of the act and how harshly the transgressor should be punished. Participants also answered questions about how they felt about themselves, including any negative emotions they experienced and their own sense of morality.

In all three experiments, researchers found participants felt less anger, contempt and disgust toward family and close friends who behaved badly. They rated them as more moral and wanted to punish or criticize them less than strangers. However, participants also felt more shame, guilt and embarrassment and reported somewhat more negative evaluations of their own morality when someone close to them committed a moral or ethical violation.

In the fourth experiment, participants were physically paired with a romantic partner, a close friend or a relative stranger. They were then taken to separate rooms and asked to respond in writing to a series of questions about themselves. The pairs then swapped answers (via a research assistant) and were told to transcribe them into a book. In the first round, the partners received genuine answers, but in the second round, participants were given fake responses indicating their partner had behaved unethically, by lying, plagiarizing or acting selfishly. As in previous experiments, participants then answered a series of questions about their partner, the transgression, how harsh the punishment should be and their feelings about themselves. The results were similar to the first three experiments, but the effect was not as strong.

Forbes believes the less consistent effects observed in the fourth experiment may be because the unethical information presented to participants in this study was unknown to the participants prior to the experiment and was first shared with them in a very brazen way by a stranger. "It's possible that participants were upset with their close others because they did not tell the participant about the unethical acts beforehand and instead chose to tell the researcher. Hearing about an unethical behavior by someone you care about from a stranger is likely to be a bit more jarring than hearing about it directly from your friend or loved one," she said.

"Across a diverse range of methods with both student and online samples, our findings suggest that having a close relationship with the transgressor heavily affects responses to their bad behavior, supporting the call for social-relational factors to be more strongly incorporated into models of moral judgment," said Forbes.

The findings are important because, in everyday life, unethical behaviors are often entwined with social ties, according to co-author Jennifer Stellar, PhD, also from the University of Toronto.

"Identifying that observers are more lenient toward close others who transgress raises deeper concerns about how moral norms are policed by individuals in these situations," she said. "This may allow people to either overlook and/or fail to call out transgressions committed by close others, which poses a danger for maintaining the moral norms in society."

The researchers focused on close relationships, but Stellar believes that the same processes may apply to other relationships, such as shared group membership, and that should be incorporated in future research.

"One important limitation in our work is that we did not examine responses to extremely severe immoral actions," said Forbes. "Highly immoral acts would certainly place a greater strain on the relationship and therefore could show different effects."

One relevant example she often uses when talking about this work is a quote by "TODAY" host Savannah Guthrie in response to the accusations of sexual misconduct against Guthrie's colleague and friend Matt Lauer. Guthrie responded to news of the accusations on air, saying, "We are grappling with a dilemma that so many people have faced these past few weeks: How do you reconcile your love for someone with the revelation that they have behaved badly?"

"In the case of very severe unethical actions, the conflict with one's moral values is likely more apparent. We don't yet know how close others may respond because this is very difficult to study," said Forbes.

Another limitation was that the participants in the first three experiments were approximately 80% white.

Read more at Science Daily

First detection of light from behind a black hole

Watching X-rays flung out into the universe by the supermassive black hole at the center of a galaxy 800 million light-years away, Stanford University astrophysicist Dan Wilkins noticed an intriguing pattern. He observed a series of bright flares of X-rays -- exciting, but not unprecedented -- and then, the telescopes recorded something unexpected: additional flashes of X-rays that were smaller, later and of different "colors" than the bright flares.

According to theory, these luminous echoes were consistent with X-rays reflected from behind the black hole -- but even a basic understanding of black holes tells us that is a strange place for light to come from.

"Any light that goes into that black hole doesn't come out, so we shouldn't be able to see anything that's behind the black hole," said Wilkins, who is a research scientist at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford and SLAC National Accelerator Laboratory. It is another strange characteristic of the black hole, however, that makes this observation possible. "The reason we can see that is because that black hole is warping space, bending light and twisting magnetic fields around itself," Wilkins explained.

The strange discovery, detailed in a paper published July 28 in Nature, is the first direct observation of light from behind a black hole -- a scenario that was predicted by Einstein's theory of general relativity but never confirmed, until now.

"Fifty years ago, when astrophysicists starting speculating about how the magnetic field might behave close to a black hole, they had no idea that one day we might have the techniques to observe this directly and see Einstein's general theory of relativity in action," said Roger Blandford, a co-author of the paper who is the Luke Blossom Professor in the School of Humanities and Sciences and Stanford and SLAC professor of physics and particle physics.

How to see a black hole

The original motivation behind this research was to learn more about a mysterious feature of certain black holes, called a corona. Material falling into a supermassive black hole powers the brightest continuous sources of light in the universe, and as it does so, forms a corona around the black hole. This light -- which is X-ray light -- can be analyzed to map and characterize a black hole.

The leading theory for what a corona is starts with gas sliding into the black hole where it superheats to millions of degrees. At that temperature, electrons separate from atoms, creating a magnetized plasma. Caught up in the powerful spin of the black hole, the magnetic field arcs so high above the black hole, and twirls about itself so much, that it eventually breaks altogether -- a situation so reminiscent of what happens around our own Sun that it borrowed the name "corona."

"This magnetic field getting tied up and then snapping close to the black hole heats everything around it and produces these high energy electrons that then go on to produce the X-rays," said Wilkins.

As Wilkins took a closer look to investigate the origin of the flares, he saw a series of smaller flashes. These, the researchers determined, are the same X-ray flares but reflected from the back of the disk -- a first glimpse at the far side of a black hole.

"I've been building theoretical predictions of how these echoes appear to us for a few years," said Wilkins. "I'd already seen them in the theory I've been developing, so once I saw them in the telescope observations, I could figure out the connection."

Future observations

The mission to characterize and understand coronas continues and will require more observation. Part of that future will be the European Space Agency's X-ray observatory, Athena (Advanced Telescope for High-ENergy Astrophysics). As a member of the lab of Steve Allen, professor of physics at Stanford and of particle physics and astrophysics at SLAC, Wilkins is helping to develop part of the Wide Field Imager detector for Athena.

"It's got a much bigger mirror than we've ever had on an X-ray telescope and it's going to let us get higher resolution looks in much shorter observation times," said Wilkins. "So, the picture we are starting to get from the data at the moment is going to become much clearer with these new observatories."

Co-authors of this research are from Saint Mary's University (Canada), Netherlands Institute for Space Research (SRON), University of Amsterdam and The Pennsylvania State University.

Read more at Science Daily

Water as a metal

Every child knows that water conducts electricity -- but this refers to "normal" everyday water that contains salts. Pure, distilled water, on the other hand, is an almost perfect insulator. It consists of H2O molecules that are loosely linked to one another via hydrogen bonds. The valence electrons remain bound and are not mobile. To create a conduction band with freely moving electrons, water would have to be pressurised to such an extent that the orbitals of the outer electrons overlap. However, a calculation shows that this pressure is only present in the core of large planets such as Jupiter.

Providing electrons

An international collaboration of 15 scientists from eleven research institutions has now used a completely different approach to produce a aqueous solution with metallic properties for the first time and documented this phase transition at BESSY II. To do this, they experimented with alkali metals, which release their outer electron very easily.

Avoiding explosion

However, the chemistry between alkali metals and water is known to be explosive. Sodium or other alkali metals immediately start to burn in water. But the team found a way to keep this violent chemistry in check: They did not throw a piece of alkali metal into water, but they did it the other way round: they put a tiny bit of water on a drop of alkali metal, a sodium-potassium (Na-K) alloy, which is liquid at room temperature.

Experiment at BESSY II

At BESSY II, they set up the experiment in the SOL³PES high vacuum sample chamber at the U49/2 beamline. The sample chamber contains a fine nozzle from which the liquid Na-K alloy drips. The silver droplet grows for about 10 seconds until it detaches from the nozzle. As the droplet grows, some water vapour flows into the sample chamber and forms an extremely thin skin on the surface of the droplet, only a few layers of water molecules. This almost immediately causes the electrons as well as the metal cations to dissolve from the alkali alloy into the water. The released electrons in the water behave like free electrons in a conduction band.

Golden water skin

"You can see the phase transition to metallic water with the naked eye! The silvery sodium-potassium droplet covers itself with a golden glow, which is very impressive," reports Dr. Robert Seidel, who supervised the experiments at BESSY II. The thin layer of gold-coloured metallic water remains visible for a few seconds. This enabled the team led by Prof. Pavel Jungwirth, Czech Academy of Sciences, Prague, to prove with spectroscopic analyses at BESSY II and at the IOCB in Prague that it is indeed water in a metallic state.

Read more at Science Daily

New insights into the relationship between how we feel and our views on aging

A new study finds that the disconnect between how old we feel and how old we want to be can offer insights into the relationship between our views on aging and our health.

Subjective age discordance (SAD) -- the difference between how old you feel and how old you would like to be -- is a fairly new concept in the psychology of aging. However, the work to this point has used SAD to look at longitudinal data and how people's views on aging evolve over months or years.

"We wanted to see whether SAD could help us assess day-to-day changes in our views on aging, and how that may relate to our physical health and well-being," says Shevaun Neupert, co-author of the study and a professor of psychology at North Carolina State University.

SAD is determined by taking how old you feel, subtracting how old you would like to be and then dividing it by your actual age. The higher the score, the more you feel older than you want to be.

For this study, researchers enrolled 116 adults aged 60-90 and 107 adults aged 18-36. Study participants filled out an online survey every day for eight days. The survey was designed to assess how old participants felt each day, their ideal age, their positive and negative mood over the course of the day, any stresses they experienced, and any physical complaints, such as backaches or cold symptoms.

"We found that both older adults and younger adults experienced SAD," Neupert says. "It was more pronounced in older adults, which makes sense. However, it fluctuated more from day to day in younger adults, which was interesting."

"We think younger adults are getting pushed and pulled more," says Jennifer Bellingtier, first author of the paper, and a researcher at Friedrich Schiller University Jena. "Younger adults are concerned about negative stereotypes associated with aging, but may also be dealing with negative stereotypes associated with younger generations and wishing they had some of the privileges and status associated with being older."

Two additional findings stood out.

"On days when the age you feel is closer to your ideal age, people tend to have a more positive mood," Bellingtier says. "And, on average, people who have more health complaints also had higher SAD scores."

Neither finding was surprising, but both show the value of the SAD concept as a tool for understanding people's views on age and aging. It may also offer a new approach for the way we think about aging and its impacts on health.

"Previous research has found that how old you feel can affect your physical and mental well-being, and interventions to address that have focused on trying to make people feel younger," Neupert says.

Read more at Science Daily

Study shows why beer mats do not fly in a straight line

Beer mats protect tables from unsightly condensation rings. However, they are sometimes also misused as projectiles. Usually with little success: after just a short time, the cardboard coaster leaves its path, spins off to the side, and falls to the ground. But why is that so?

Physicists at the Helmholtz Institute of Radiation and Nuclear Physics and the Argelander Institute for Astronomy at the University of Bonn have now investigated this question. According to them, the behavior of the beer mat is inevitable, at least when employing the usual throwing technique: it unavoidably begins to drift off after 0.45 seconds at most. Playing cards go awry after just 0.24 seconds, CDs after 0.8 seconds.

The reason for this is the interaction between gravity, lift, and the conservation of angular momentum: the mat tips backwards shortly after being thrown due to gravity. This gives it an angle of attack, similar to a landing aircraft. This angle creates lift in the airflow. "However, the lifting force is not applied in the center of the mat, but rather in the front third," explains PhD student Johann Ostmeyer, who came up with the idea for the study.

This would normally soon make the round cardboard flip over. And it actually does -- but only if it is thrown in a rather unconventional manner. "A beer mat is usually rotated when thrown, similar to a frisbee," says Ostmeyer's colleague Christoph Schürmann from the Argelander Institute for Astronomy at the University of Bonn. "This turns it into a kind of spinning top." This rotation stabilizes the flight and prevents flipping over. Instead, the lifting force causes the mat to drift off to the side -- to the right, if it is rotated counterclockwise; otherwise to the left.

Beer mat throwing machine designed

At the same time, it straightens up -- so it is no longer parallel with the ground but instead stands upright in the air like a rotating wheel. In this position, the mat has a backspin -- if it were to actually stand up like a wheel on the ground, it would thus travel back to its starting point. While in flight, it quickly loses height and falls to the ground. This process is characteristic of all flat, round objects.

The idea of the study arose during an excursion by the physics show team from the University of Bonn to Munich. The event regularly captivates several hundred visitors with its fascinating physical experiments. While the participants were visiting a bar together, they wondered why flying beer mats behave the way that they do.

On their return, the physicists tackled this question systematically: They specially designed a beer mat throwing machine and recorded the flights with a high-speed camera. This allowed them to verify whether their theoretical predictions corresponded to their practical observations. "There is no application for the project," explains Prof. Dr. Carsten Urbach from the Helmholtz Institute of Radiation and Nuclear Physics, an institute of the Department of Physics and Astronomy at the University of Bonn. "However, the problem is clear for laypeople and physicists alike. And it wonderfully illustrates the entire process by which the natural sciences acquire knowledge -- from the observation to the theory and its experimental testing, right through to its adjustment and further development."

Playing cards travel distances of up to 60 meters

Incidentally, beer mats travel most stably, and thus the furthest, if they rotate very quickly -- a trick that has also been mastered by the world's best playing card thrower Rick Smith Jr., whose record throwing distance is over 60 meters. However, quickly rotating beer mats do not travel straight for more than 0.45 seconds. "Those who want to throw really far and precisely should place the mat in a vertical position and apply backward rotation," explains Ostmeyer -- and then, in the same breath, warns about possible injuries.

It is not without reason that there is a precautionary apology at the end of the publication: "Our sincere apologies to everyone hit by a beer mat, be it through inaccurate aim or due to us instigating others to perform silly experiments."

Read more at Science Daily

On the hunt for ‘hierarchical’ black holes

Black holes, detected by their gravitational wave signal as they collide with other black holes, could be the product of much earlier parent collisions. Such an event has only been hinted at so far, but scientists at the University of Birmingham in the UK, and Northwestern University in the US, believe we are getting close to tracking down the first of these so-called 'hierarchical' black holes.

In a review paper, published in Nature Astronomy, Dr Davide Gerosa, of the University of Birmingham, and Dr Maya Fishbach of Northwestern University, suggest that recent theoretical findings together with astrophysical modelling and recorded gravitational wave data will enable scientists to accurately interpret gravitational wave signals from these events.

Since the first gravitational wave was detected by the LIGO and Virgo detectors in September 2015, scientists have produced increasingly nuanced and sophisticated interpretations of these signals.

There is now fervent activity to prove the existence of so-called 'hierarchical mergers' although the detection of GW190521 in 2019 -- the most massive black hole merger yet detected -- is thought to be the most promising candidate so far.

"We believe that most of the gravitational waves so far detected are the result of first generation black holes colliding," says Dr Gerosa. "But we think there's a good chance that others will contain the remnants of previous mergers. These events will have distinctive gravitational wave signatures suggesting higher masses, and an unusual spin caused by the parent collision."

Understanding the characteristics of the environment in which such objects might be produced will also help narrow the search. This must be an environment with a large number of black holes, and one that is sufficiently dense to retain the black holes after they have merged, so they can go on and merge again.

These could be, for example, nuclear star clusters, or accretion disks -- containing a flow of gas, plasma and other particles -- surrounding the compact regions at the centre of galaxies.

"The LIGO and Virgo collaboration has already discovered more than 50 gravitational wave events," says Dr Fishbach. "This will expand to thousands over the next few years, giving us so many more opportunities to discover and confirm unusual objects like hierarchical black holes in the universe."

From Science Daily

Cultural biases impact native fish, too

From art to religion to land use, much of what is deemed valuable in the United States was shaped centuries ago by the white male perspective. Fish, it turns out, are no exception.

A study published in Fisheries Magazine, a journal of the American Fisheries Society, explores how colonialist attitudes toward native fishes were rooted in elements of racism and sexism. It describes how those attitudes continue to shape fisheries management today, often to the detriment of native fishes.

The study, led by the University of California, Davis, with Nicholls State University and a national team of fisheries researchers, found that nearly all states have policies that encourage overfishing native species. The study maintains that the term "rough fish" is pejorative and degrading to native fish.

"That has bothered me for a long time," said lead author Andrew Rypel, co-director of the Center for Watershed Sciences and the Peter B. Moyle and California Trout Chair in Coldwater Fish Ecology at UC Davis. He and others have been disturbed by images of "glory killings" of native fish that periodically pop up on the internet, as well as the lump categorization of less preferred species as "rough" or "trash" fish.

"When you trace the history of the problem, you quickly realize it's because the field was shaped by white men, excluding other points of view," Rypel said. "Sometimes you have to look at that history honestly to figure out what to do."

The study offers several recommendations for how anglers and fisheries managers can shift to a new paradigm that's more inclusive and beneficial to all fish and people.

A 'rough' start

The term "rough fish" dates to commercial riverboat fishing in the mid-late 1800s. Slow, heavy boats would lighten their loads by "rough-dressing" -- removing organs but not filleting -- less desirable species and discarding them. Biologists came to use the term to describe an unsubstantiated idea that native fish limit game fish species historically desired by Europeans. That attitude posed a major threat to many native species, which were killed in large numbers.

For instance, the alligator gar, an ancient species that can grow more than 8 feet long and weigh 300 pounds, was particularly persecuted in the past century. Called a "wolf among fishes," poison, dynamite and electrocution were used to greatly reduce its population. But now some fishers spend thousands of dollars for the opportunity to catch and release a giant gar. In 2021, Minnesota changed its statute to describe gar as a "game fish" rather than a "rough fish."

Co-author Solomon David has helped fuel renewed appreciation for gar and its relative, bowfin. He runs the GarLab at Nicholls State University in Louisiana, where he is an assistant professor. He said many native fishes, such as suckers and gars, have long been valued by Indigenous people and people of color.

"European colonists heavily influenced what fishes were more valuable, often the species that looked more similar to what they're used to," David said. "So trout, bass and salmon got their value while many other native species got pushed to the wayside."

Limited view

The study authors conducted a survey of fishing regulations across the United States to compare policies and bag limits on "rough fish" with those of largemouth bass, a ubiquitous sport fish.

"When I was a kid fishing, you might go to the river with a worm and catch all these interesting species," Rypel said. "The guidebook would just say 'rough fish, bag unlimited.' Not much has changed since I was kid."

The study found that no states had bag limits rivaling those for the bass. While black basses were often managed at five fish per day, regulations for most native fishes were extremely liberal. Forty-three states had unlimited bag limits for at least one native species. In the remaining states, bag limits were between 15 and 50 fish a day.

Freshwater ecosystems are threatened by pollution, habitat loss and climate change. Up to half of fish species globally are in some form of decline, and 83 percent of native California fish species are declining. Native fishes help ecosystems in many ways, including nutrient cycling and food chain support for other native species. The authors pointedly call for a "rewrite" in managing them.

Recommendations

The study's recommendations for that rewrite include:
 

• Stop saying "rough fish." They suggest "native fish" as a simple alternative.
• Integrate Indigenous perspectives into fisheries management.
• Revisit species bag limits. Lower bag limits for native species until the science is conducted to confirm they could be higher. The study takes particular note of the fast-growing bowfishing market that has contributed to removing native species.
• Support science on native fishes. Game fish receive 11 times more research and management attention in American Fisheries Society journals than do "rough fish." To learn the true value of native fishes, more research is required.
• Co-manage species that have co-evolved, such as freshwater mussels and fish that host them.
• Correct misinformation and enhance science educationthrough outreach and education for all ages.

"We have a chance to redirect fisheries science and conservation and expand it with respect for biodiversity and diversity," David said. "It's been a long time coming. Change is slow, but we have an opportunity here, and we should take advantage of it."

Read more at Science Daily

Scientists discover early signs of frontotemporal dementia in personalized cerebral organoids

Frontotemporal dementias are a group of fatal and debilitating brain disorders for which there are no cures. In an article published July 26 in Cell, Mount Sinai researchers describe how they were able to recreate much of the damage seen in a widely studied form of the disease by growing special types of cerebral organoids in petri dishes. This form of the disease is caused by a genetic mutation in tau, a protein that is a hallmark of Alzheimer's disease and other dementias. By studying these organoids, the scientists discovered how the mutated tau protein may trigger the death of a specific class of neurons known to be vulnerable in frontotemporal dementia. They also showed that they could prevent the death of these neurons by treating the organoids with an experimental drug, originally designed to combat Crohn's disease.

"Frontotemporal dementia is a devastating disease for patients and their loved ones. Understanding the causes of dementia can be difficult, as most of the damage to the brain occurs well before any symptoms appear. It's like trying to unravel the events that created a crime scene. In this study, we were able to model many aspects of the pathology seen in the brains of patients who carry the V337M mutation in tau," said Alison M. Goate, DPhil, Director, Ronald M. Loeb Center for Alzheimer's Disease at Mount Sinai, and a senior author of the study. "Our results identified several very early transcriptomic and proteomic changes that lead to the formation of tau pathology and neuronal death. Our goal is to help researchers develop novel treatments against frontotemporal dementias and prevent the suffering experienced by patients and their families."

Frontotemporal dementia is a rare form of dementia that usually begins between ages 40 and 60. It affects the front and side (temporal) areas of the brain, leading to behavior changes and difficulty with speaking and thinking.

The study was led by Kathryn Bowles, PhD, an instructor in Dr. Goate's lab at Mount Sinai. Working with scientists at the Neural Stem Cell Institute (NSCI) in Rensselaer, New York, Washington University in St. Louis, Missouri, Massachusetts General Hospital in Boston, and the University of Southern California, Los Angeles, the researchers created thousands of cerebral organoids from induced pluripotent stem cells (iPSCs).

Induced pluripotent stem cells are created by genetically and chemically reprogramming a person's skin or blood cells into newborn stem cells, which have the potential to become any cell in the body. From these stem cells, the NSCI created thousands of tiny, 3D cerebral organoids, which mimic the early growth and development of the cerebral cortex for intensive study by collaborating scientific groups.

"Induced pluripotent stem cells are powerful tools. They allow researchers to study each patient's personalized disease in a petri dish," said Sally Temple, PhD, Scientific Director of the NSCI and a senior author of the study. "In this study we were able to take this idea to the next level. By combining iPSC-organoid technology with high-throughput, single cell gene activity analysis, we were able to get a better look at what might be going on in a patient's brain at early stages of disease development, even before symptoms emerge."

In this study, the researchers examined the growth and development of organoids derived from the stem cells of three patients, all of whom carried the V337M mutation in tau. They then compared their results with those observed in "isogenic," control organoids. The controls were derived from patient stem cells in which the disease-causing mutation was genetically corrected.

After six months of growth, signs of neurodegeneration were seen in the organoids. Most notably, the patient-derived organoids had fewer excitatory neurons than those derived from the control cells, demonstrating that the tau mutation was sufficient to cause higher levels of cell death of this specific class of neurons. Excitatory neurons usually fire in response to the neurochemical glutamate and are known to die at abnormally high levels in frontotemporal dementia. The patient-derived organoids also had higher levels of harmful versions of tau protein and elevated levels of inflammation.

"Excitatory neuron cell death, tau protein deposits, and inflammation are classic hallmarks of the kind of damage seen in many forms of frontotemporal dementia," said Dr. Bowles. "What we wanted to know next was: what are the cellular and molecular processes that occur before the appearance of these disease hallmarks?"

The researchers found clues by examining two- and four-month-old organoids.

For instance, two-month-old mutant organoids appeared to be undergoing elevated levels of cellular stress, whereas four-month-old ones developed problems with autophagy, or the recycling of proteins. The results also suggested that during these early months the excitatory neurons matured faster in the mutant organoids than in the controls.

Other experiments suggested that many of these changes may have been the by-product of a complex interaction between mutant tau, excitatory neuronal genes, and ELAVL4, a protein that controls gene activity by binding to ribonucleic acid (RNA) molecules.

"Our results suggest that the V337M mutant tau sets off a vicious cycle in the brain that puts excitatory neurons under great stress. It hastens the production of new proteins needed for maturation but prevents disposal of the proteins that are being replaced," Dr. Bowles said.

Further experiments supported this idea. For example, excitatory neurons in mutant organoids were less likely to survive in the presence of toxic levels of glutamate than those in control organoids. The researchers then found that this could be prevented by apilimod, an experimental drug designed to alter a cell's protein recycling system. In other words, the researchers saw no difference in levels of glutamate-induced cell death between mutant and control organoids when they treated samples with apilimod.

Read more at Science Daily

T cell response not critical for immune memory to SARS-CoV-2 or recovery from COVID-19, study finds

New research conducted in monkeys reveals that T cells are not critical for the recovery of primates from acute COVID-19 infections. T cell depletion does not induce severe disease, and T cells do not account for the natural resistance of rhesus macaques to severe COVID-19. Furthermore, strongly T cell-depleted macaques still develop potent memory responses to a second infection.

The findings, published in the mBio, an open-access journal of the American Society for Microbiology, have implications for the development of second-generation vaccines and therapeutics.

"We started this study early in the pandemic, trying to figure out how to make a good model to study the disease in humans using animals. The monkeys turned out to be more resistant to the disease than we expected, so we wanted to try to figure out why that was and try to gain some insights into the disease in humans as well," said lead study author Kim Hasenkrug, PhD, senior investigator in the Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, in Hamilton, Montana. "We now know that the antibody response is the most critical response for protection by vaccination, not the T cell response."

In the new study, the researchers used classic reagents known to deplete CD4+ and CD8+ T cells in rhesus macaques. While CD8+ T cells directly attack infected cells and kill them, CD4+ T cells are helper T cells that trigger the immune response by recognizing pathogens and secreting cytokines, small proteins, that signal other immune cells to act, including CD8+ T cells and antibody-producing B cells.

One week after depleting the macaques of CD4+ T cells, CD8+ T cells, or both at the same time, the researchers infected the animals with SARS-CoV-2. "We depleted, we infected them and then we continued the depletions during the first week of infection to make sure the animals were well depleted. Then we studied their blood to see how they were responding in terms of their T cells and B cells," said Hasenkrug. For six weeks, the researchers studied nasal swabs and bronchoalveolar lavages to measure virus in the nose, mouth and lungs, and rectal swabs to see if the gut was shedding virus. After six weeks, the researchers re-challenged the monkeys with SARS-CoV-2 and they repeated their collection of virus and blood samples, which allowed the researchers to evaluate immune memory responses. "If there is a memory response, you get a much quicker immune response and control of the virus. That is how vaccinations work. Once your body has seen a viral pathogen, the next time it sees it, you can get a much faster and stronger immune response," said Dr. Hasenkrug.

The researchers found that the monkeys were able to mount a good memory response against the virus regardless of T cell depletion. "We found we got really good memory responses regardless of whether we depleted T cells or not. Basically, we found very strong virus neutralizing antibodies, and they are the most important antibodies in controlling the infection. That was unexpected by most immunologists, virologists and vaccinologists," said Hasenkrug.

"The other thing that happens during a memory response is that antibodies mature, becoming, stronger and more potent at binding the viral pathogen. We saw indications of this through what's called "class switching,," said Hasenkrug.

"Class switching" was also unexpected in these monkeys with depleted T cells. "We don't have a firm explanation as to why that happened, but we think it involves some sort of compensatory response, which you can see in our study. For example, when we depleted CD8+ T cells, we saw stronger CD4+ T cell or B cells responses in some animals. When the animals are missing something, they will try to make up for it by making more of something else."

Hasenkrug doesn't know why the T cells didn't turn out to be more important, but it is probably a good thing that they are not required, because then, people who fail to mount sufficient T cell responses still have opportunities to recover.

Read more at Science Daily

Hubble finds evidence of water vapor at Jupiter's moon Ganymede

For the first time, astronomers have uncovered evidence of water vapor in the atmosphere of Jupiter's moon Ganymede. This water vapor forms when ice from the moon's surface sublimates -- that is, turns from solid to gas.

Scientists used new and archival datasets from NASA's Hubble Space Telescope to make the discovery, published in the journal Nature Astronomy.

Previous research has offered circumstantial evidence that Ganymede, the largest moon in the solar system, contains more water than all of Earth's oceans. However, temperatures there are so cold that water on the surface is frozen solid. Ganymede's ocean would reside roughly 100 miles below the crust; therefore, the water vapor would not represent the evaporation of this ocean.

Astronomers re-examined Hubble observations from the last two decades to find this evidence of water vapor.

In 1998, Hubble's Space Telescope Imaging Spectrograph (STIS) took the first ultraviolet (UV) images of Ganymede, which revealed in two images colorful ribbons of electrified gas called auroral bands, and provided further evidence that Ganymede has a weak magnetic field.

The similarities in these UV observations were explained by the presence of molecular oxygen (O2). But some observed features did not match the expected emissions from a pure O2 atmosphere. At the same time, scientists concluded this discrepancy was likely related to higher concentrations of atomic oxygen (O).

As part of a large observing program to support NASA's Juno mission in 2018, Lorenz Roth of the KTH Royal Institute of Technology in Stockholm, Sweden led the team that set out to measure the amount of atomic oxygen with Hubble. The team's analysis combined the data from two instruments: Hubble's Cosmic Origins Spectrograph (COS) in 2018 and archival images from the Space Telescope Imaging Spectrograph (STIS) from 1998 to 2010.

To their surprise, and contrary to the original interpretations of the data from 1998, they discovered there was hardly any atomic oxygen in Ganymede's atmosphere. This means there must be another explanation for the apparent differences in these UV aurora images.

Roth and his team then took a closer look at the relative distribution of the aurora in the UV images. Ganymede's surface temperature varies strongly throughout the day, and around noon near the equator it may become sufficiently warm that the ice surface releases (or sublimates) some small amounts of water molecules. In fact, the perceived differences in the UV images are directly correlated with where water would be expected in the moon's atmosphere.

"So far only the molecular oxygen had been observed," explained Roth. "This is produced when charged particles erode the ice surface. The water vapor that we measured now originates from ice sublimation caused by the thermal escape of water vapor from warm icy regions."

This finding adds anticipation to ESA (European Space Agency)'s upcoming mission, JUICE, which stands for JUpiter ICy moons Explorer. JUICE is the first large-class mission in ESA's Cosmic Vision 2015-2025 program. Planned for launch in 2022 and arrival at Jupiter in 2029, it will spend at least three years making detailed observations of Jupiter and three of its largest moons, with particular emphasis on Ganymede as a planetary body and potential habitat.

Ganymede was identified for detailed investigation because it provides a natural laboratory for analysis of the nature, evolution and potential habitability of icy worlds in general, the role it plays within the system of Galilean satellites, and its unique magnetic and plasma interactions with Jupiter and its environment.

"Our results can provide the JUICE instrument teams with valuable information that may be used to refine their observation plans to optimize the use of the spacecraft," added Roth.

Right now, NASA's Juno mission is taking a close look at Ganymede and recently released new imagery of the icy moon. Juno has been studying Jupiter and its environment, also known as the Jovian system, since 2016.

Understanding the Jovian system and unravelling its history, from its origin to the possible emergence of habitable environments, will provide us with a better understanding of how gas giant planets and their satellites form and evolve. In addition, new insights will hopefully be found on the habitability of Jupiter-like exoplanetary systems.

Read more at Science Daily

Using archeology to better understand climate change

Throughout history, people of different cultures and stages of evolution have found ways to adapt, with varying success, to the gradual warming of the environment they live in. But can the past inform the future, now that climate change is happening faster than ever before?

Yes, say an international team of anthropologists, geographers and earth scientists in Canada, the U.S. and France led by Université de Montréal anthropologist Ariane Burke.

In a paper published today in the Proceedings of the National Academy of Sciences, Professor Burke and her colleagues make a case for a new and evolving discipline called "the archeology of climate change."

It's an interdisciplinary science that uses data from archeological digs and the palaeoclimate record to study how humans interacted with their environment during past climate-change events such as the warming that followed the last ice age, more than 10,000 years ago.

What the scientists hope to identify are the tipping points in climate history that prompted people to reorganize their societies to survive, showing how cultural diversity, a source of human resilience in the past, is just as important today as a bulwark against global warming.

"The archaeology of climate change combines the study of environmental conditions and archaeological information," said Burke, who runs the Hominin Dispersals Research Group and the Ecomorphology and Paleoanthropology Laboratory.

"What this approach allows us to do identify the range of challenges faced by people in the past, the different strategies they used to face these challenges and ultimately, whether they succeeded or not."

For instance, studying the rapid warming that occurred between 14,700 and 12,700 years ago, and how humans coped with it as evidenced in the archeological record, can help climate specialists model possible outcomes of climate change in the future, Burke said.

Her paper is co-authored with UdeM anthropologist Julien Riel-Salvatore and colleagues from Bishop's University, Université du Québec à Montréal, the University of Colorado and the CNRS, in France.

Historically, people from different walks of life have found a variety of ways to adapt to the warming of their climate, and these can inform the present and help prepare for the future, the researchers say.

For example, traditional farming practices -- many of which are still practiced today -- are valid alternatives that can be used to redesign industrial farming, making it more sustainable in the future, they say.

Indigenous cultures have a major role to play in teaching us how to respond to climate change -in the Canadian Arctic, for instance, Indigenous people have a detailed knowledge of the environment that's key to be essential to planning a sustainable response, said Burke.

"Similarly, indigenous farmers all over the world cultivate a wide variety of crop types that won't all respond to changing climate conditions in the same way," she said. "They are preserving crop diversity in the global food chain and if and when the main crop types we currently rely on fail, this diversity could well prove to be a lifeline.

Read more at Science Daily

Research 'final nail in the coffin' of Paranthropus as hard object feeders

New research from the University of Otago debunks a long-held belief about our ancestors' eating habits.

For more than 60 years, researchers have believed Paranthropus, a close fossil relative of ours which lived about one to three million years ago, evolved massive back teeth to consume hard food items such as seeds and nuts, while our own direct ancestors, the genus Homo, is thought to have evolved smaller teeth due to eating softer food such as cooked food and meats.

However, after travelling to several large institutes and museums in South Africa, Japan and the United Kingdom and studying tooth fractures in more than 20,000 teeth of fossil and living primate species, Dr Ian Towle, an Otago biological anthropologist, working with Dr Carolina Loch, of the Faculty of Dentistry, says this "neat picture is far more complex than once thought."

"By individually studying each tooth and recording the position and size of any tooth fractures, we show tooth chipping does not support regular hard food eating in Paranthropus robustus, therefore potentially putting an end to the argument that this group as a whole were hard food eaters," he says.

Dr Towle says the findings challenge our understanding of dietary and behavioural changes during human evolution.

"The results are surprising, with human fossils so far studied -- those in our own genus Homo -- showing extremely high rates of tooth fractures, similar to living hard object eating primates, yet Paranthropus show extremely low levels of fracture, similar to primates that eat soft fruits or leaves.

"Although in recent years there has been a slow acceptance that another species of Paranthropus, Paranthropus boisei, found in East Africa, was unlikely to have regularly eaten hard foods, the notion that Paranthropus evolved their large dental apparatus to eat hard foods has persisted. Therefore, this research can be seen as the final nail in the coffin of Paranthropus as hard object feeders."

The fact that humans show such contrasting chipping patterns is equally significant and will have "knock on" effects for further research, particularly research on dietary changes during human evolution, and why the human dentition has evolved the way it has, he says.

"The regular tooth fractures in fossil humans may be caused by non-food items, such as grit or stone tools. However, regardless of the cause, these groups were subjected to substantial tooth wear and fractures. So, it raises questions to why our teeth reduced in size, especially compared to groups like Paranthropus."

Dr Towle's research will now focus on if our dentition evolved smaller due to other factors to allow other parts of the skull to expand, leading to evolution then favouring other tooth properties to protect it against wear and fracture, instead of increased tooth size.

"This is something we are investigating now, to see if tooth enamel may have evolved different characteristics among the great apes. Our research as a whole may also have implications for our understanding of oral health, since fossil human samples typically show immaculate dental health.

Read more at Science Daily

15,000-year-old viruses discovered in Tibetan glacier ice

Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.

The findings, published today in the journal Microbiome, could help scientists understand how viruses have evolved over centuries. For this study, the scientists also created a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.

"These glaciers were formed gradually, and along with dust and gases, many, many viruses were also deposited in that ice," said Zhi-Ping Zhong, lead author of the study and a researcher at The Ohio State University Byrd Polar and Climate Research Center who also focuses on microbiology. "The glaciers in western China are not well-studied, and our goal is to use this information to reflect past environments. And viruses are a part of those environments."

The researchers analyzed ice cores taken in 2015 from the Guliya ice cap in western China. The cores are collected at high altitudes -- the summit of Guliya, where this ice originated, is 22,000 feet above sea level. The ice cores contain layers of ice that accumulate year after year, trapping whatever was in the atmosphere around them at the time each layer froze. Those layers create a timeline of sorts, which scientists have used to understand more about climate change, microbes, viruses and gases throughout history.

Researchers determined that the ice was nearly 15,000 years old using a combination of traditional and new, novel techniques to date this ice core.

When they analyzed the ice, they found genetic codes for 33 viruses. Four of those viruses have already been identified by the scientific community. But at least 28 of them are novel. About half of them seemed to have survived at the time they were frozen not in spite of the ice, but because of it.

"These are viruses that would have thrived in extreme environments," said Matthew Sullivan, co-author of the study, professor of microbiology at Ohio State and director of Ohio State's Center of Microbiome Science. "These viruses have signatures of genes that help them infect cells in cold environments -- just surreal genetic signatures for how a virus is able to survive in extreme conditions. These are not easy signatures to pull out, and the method that Zhi-Ping developed to decontaminate the cores and to study microbes and viruses in ice could help us search for these genetic sequences in other extreme icy environments -- Mars, for example, the moon, or closer to home in Earth's Atacama Desert."

Viruses do not share a common, universal gene, so naming a new virus -- and attempting to figure out where it fits into the landscape of known viruses -- involves multiple steps. To compare unidentified viruses with known viruses, scientists compare gene sets. Gene sets from known viruses are cataloged in scientific databases.

Those database comparisons showed that four of the viruses in the Guliya ice cap cores had previously been identified and were from virus families that typically infect bacteria. The researchers found the viruses in concentrations much lower than have been found to exist in oceans or soil.

The researchers' analysis showed that the viruses likely originated with soil or plants, not with animals or humans, based on both the environment and the databases of known viruses.

The study of viruses in glaciers is relatively new: Just two previous studies have identified viruses in ancient glacier ice. But it is an area of science that is becoming more important as the climate changes, said Lonnie Thompson, senior author of the study, distinguished university professor of earth sciences at Ohio State and senior research scientist at the Byrd Center.

"We know very little about viruses and microbes in these extreme environments, and what is actually there," Thompson said. "The documentation and understanding of that is extremely important: How do bacteria and viruses respond to climate change? What happens when we go from an ice age to a warm period like we're in now?"

Read more at Science Daily

Meet the Martian meteorite hunters

A team at the Natural History Museum (NHM), London is paving the way for future rovers to search for meteorites on Mars. The scientists are using the NHM's extensive meteorite collection to test the spectral instruments destined for the ExoMars rover Rosalind Franklin, and develop tools to identify meteorites on the surface of the red planet. The project is being presented today (23 July) at the virtual National Astronomy Meeting 2021.

The cratered surface of our nearest planetary neighbour has a long and complex history, and searching for rocks amidst more rocks may seem like a futile activity. Despite this, Martian rovers statistically have a significantly higher 'find per mile' success rate than dedicated meteorite hunts on Earth: for every kilometre travelled by a Mars rover, approximately one meteorite is found, even though the rovers have not been specifically looking for them up till now.

However, as part of the European Space Agency's upcoming ExoMars mission, the next rover -- named Rosalind Franklin, after the chemist best known for her pioneering work on DNA -- will drill down into the Martian surface to sample the soil, analyse its composition and search for evidence of past or present life buried underground.

Meteorites are important pieces of evidence that can help us understand this story; once a meteorite lands on a planet, it is subjected to the same atmospheric conditions as the rest of the surface. Chemical and physical weathering can provide information on climate weathering rates and water-rock interactions, meteorite sizes and distribution can help to infer information about the density of the atmosphere, and stony meteorites could be a potential delivery mechanism for organic materials to Mars.

"Meteorites act as a witness plate across geological time," said Sara Motaghian, the PhD student at the NHM and Imperial College London who is carrying out the work. "Generally, the surfaces of Mars we are exploring are incredibly ancient, meaning there have been billions of years for the surface to accumulate these meteorites and lock in information from across Mars' past."

The team are looking in particular at the use of multispectral imaging with the PanCam instrument, hoping to be able to highlight features in images that could be associated with meteorites as the rover moves across the surface. They are also investigating the possibility of using pattern recognition techniques to distinguish features such as Widmanstätten patterns, which can be revealed by extreme weathering.

Read more at Science Daily

'Feel good' brain messenger can be willfully controlled, new study reveals

From the thrill of hearing an ice cream truck approaching to the spikes of pleasure while sipping a fine wine, the neurological messenger known as dopamine has been popularly described as the brain's "feel good" chemical related to reward and pleasure.

A ubiquitous neurotransmitter that carries signals between brain cells, dopamine, among its many functions, is involved in multiple aspects of cognitive processing. The chemical messenger has been extensively studied from the perspective of external cues, or "deterministic" signals. Instead, University of California San Diego researchers recently set out to investigate less understood aspects related to spontaneous impulses of dopamine. Their results, published July 23 in the journal Current Biology, have shown that mice can willfully manipulate these random dopamine pulses.

Rather than only occurring when presented with pleasurable, or reward-based expectations, UC San Diego graduate student Conrad Foo led research that found that the neocortex in mice is flooded with unpredictable impulses of dopamine that occur approximately once per minute.

Working with colleagues at UC San Diego (Department of Physics and Section of Neurobiology) and the Icahn School of Medicine at Mount Sinai in New York, Foo investigated whether mice are in fact aware that these impulses -- documented in the lab through molecular and optical imaging techniques -- are actually occurring. The researchers devised a feedback scheme in which mice on a treadmill received a reward if they showed they were able to control the impromptu dopamine signals. Not only were mice aware of these dopamine impulses, the data revealed, but the results confirmed that they learned to anticipate and volitionally act upon a portion of them.

"Critically, mice learned to reliably elicit (dopamine) impulses prior to receiving a reward," the researchers note in the paper. "These effects reversed when the reward was removed. We posit that spontaneous dopamine impulses may serve as a salient cognitive event in behavioral planning."

The researchers say the study opens a new dimension in the study of dopamine and brain dynamics. They now intend to extend this research to explore if and how unpredictable dopamine events drive foraging, which is an essential aspect of seeking sustenance, finding a mate and as a social behavior in colonizing new home bases.

"We further conjecture that an animal's sense of spontaneous dopamine impulses may motivate it to search and forage in the absence of known reward-predictive stimuli," the researchers noted.

In their efforts to control dopamine, the researchers clarified that dopamine appears to invigorate, rather than initiate, motor behavior.

"This started as a serendipitous finding by a talented, and curious, graduate student with intellectual support from a wonderful group of colleagues," said study senior co-author David Kleinfeld, a professor in the Department of Physics (Division of Physical Sciences) and Section of Neurobiology (Division of Biological Sciences). "As an unanticipated result, we spent many long days expanding on the original study and of course performing control experiments to verify the claims. These led to the current conclusions."