Culture

A new global study offers a powerful confirmation of one of the most influential frameworks in all of the behavioral sciences and behavioral economics: prospect theory, which when introduced in 1979 led to a sea change in understanding the irrational and paradoxical ways individuals make decisions and interpret risk with major impacts for science, policy, and industry. Led by a Columbia University Mailman School of Public Health researcher, the new study in 19 countries and 13 languages replicates the original study that provided the empirical basis for prospect theory. Results appear in Nature Human Behaviour.

Developed by Nobel Prize winner Daniel Kahneman and Amos Tversky, prospect theory has been called the most influential theoretical framework in all of the social sciences and popularized the concept of loss aversion, which says that people prefer small guaranteed outcomes over larger risky outcomes. The 1979 paper that launched the theory is today the most cited paper in economics and is among the most cited in psychological science.

The new study led by Kai Ruggeri, PhD, assistant professor of health policy and management, is a robust test of prospect theory at a scale commensurate with its impact--and the first to test the theory in so many countries, languages, currencies, and to focus on the generalizability of the theory. Ruggeri and colleagues used nearly identical methods to those in the original study, modifying them only to make currency values relevant for a 2019 sample within each country. Participants were presented with 17 hypothetical decisions about potential gains and losses of money. For example: If you were given $1,000 to play a game, would you accept a 50 percent chance to double your money or a 100 percent guarantee of gaining an additional $500? In all, 4,098 respondents who completed all the questions were included in the final analysis.

Results of 1979 study--now confirmed in the new global study--gave rise to prospect theory and upended orthodoxies around rational choices. Among the original study's findings: people tend to be risk-seeking when maximizing gains, but risk-averse when minimizing losses; our preferences may change depending on how they are rendered sequentially; and we tend to overweight small probabilities.

The researchers found that Kahneman and Tversky's 1979 empirical foundation for proposing prospect theory broadly replicates in all the countries they studied: they report a 90 percent replication in areas directly testing the theoretical contrasts at the heart of prospect theory. Some effects were less strong than in 1979, but the researchers say this outcome may be more a testament to the ease of accessing participants in 2019, rather than suggesting a flaw in the original study conclusions. Another possible explanation--a third of respondents were aware of the concept of loss aversion--was shown to have only a weak effect on their decisions.

The implications of prospect theory have been far-reaching, extending from economics to behavioral psychology, including health behaviors. Prospect theory has helped explain why people under-use preventive care in health, how people misunderstand risk in health, and how to frame behavioral interventions for smoking cessation in terms of losses instead of gains, among many other health-related insights.

"Our study offers compelling evidence for continuing to consider prospect theory as a viable explanation of individual behavior, and therefore valuable for informing public policy around the world, in areas from financial decision-making to population well-being," says Ruggeri.

Peggah Khorrami, MPH '20, was a unique contributor and coauthor of the study. She was the first Columbia student to participate in the Junior Researcher Programme, a global initiative for early career researchers in the behavioral sciences which is now partnering with Columbia Global Programs. Junior Researcher Programme, members were a driving force for the study. For a complete list of all 32 study authors from 27 institutions, refer to the study on Nature Human Behaviour.

Maunakea, Hawaii - New evidence shows the first-ever pictures capturing the birth of a pair of planets orbiting the star PDS 70 are in fact authentic.

Using a new infrared pyramid wavefront sensor for adaptive optics (AO) correction at W. M. Keck Observatory on Maunakea in Hawaii, a Caltech-led team of astronomers applied a new method of taking family photos of the baby planets, or protoplanets, and confirmed their existence.

The team's results are published in today's issue of The Astronomical Journal.

PDS 70 is the first known multiplanetary system where astronomers can witness planet formation in action. The first direct image of one of its planets, PDS 70b, was taken in 2018 followed by multiple images taken at different wavelengths of its sibling, PDS 70c, in 2019. Both Jupiter-like protoplanets were discovered by the European Southern Observatory's Very Large Telescope (VLT).

"There was some confusion when the two protoplanets were first imaged," said Jason Wang, a Heising-Simons Foundation 51 Pegasi b Fellow at Caltech and lead author of the study. "Planet embryos form from a disk of dust and gas surrounding a newborn star. This circumstellar material accretes onto the protoplanet, creating a kind of smokescreen that makes it difficult to differentiate the dusty, gaseous disk from the developing planet in an image."

To help provide clarity, Wang and his team developed a method to disentangle the image signals from the circumstellar disk and the protoplanets.

"We know the disk's shape should be a symmetrical ring around the star whereas a planet should be a single point in the image," said Wang. "So even if a planet appears to sit on top of the disk, which is the case with PDS 70c, based on our knowledge of how the disk looks throughout the whole image, we can infer how bright the disk should be at the location of the protoplanet and remove the disk signal. All that's left over is the planet's emission."

The team snapped images of PDS 70 with the Near-Infrared Camera (NIRC2) on the Keck II telescope, marking first science for a vortex coronagraph installed in NIRC2 as part of a recent upgrade, combined with the Observatory's upgraded AO system consisting of a new infrared pyramid wavefront sensor and real-time control computer.

"The new infrared detector technology used in our pyramid wavefront sensor has dramatically improved our ability to study exoplanets, especially those around low-mass stars where planet formation is actively occurring," said Sylvain Cetre, software engineer at Keck Observatory and one of the lead developers of the AO upgrade. "It will also allow us to improve the quality of our AO correction for harder to image targets like the center of our galaxy."

This project benefited from the innovative infrared sensor that measures distortions in light caused by the Earth's atmosphere.

"New technology is a science multiplier," says Peter Kurczynski, Program Director at the National Science Foundation, which contributed funding to this project. "It enables investigations that were never before possible."

AO is a technique used to remove the atmospheric blurring that distorts astronomical images. With the new infrared pyramid wavefront sensor and real-time controller installed, Keck Observatory's AO system is able to deliver sharper, more detailed images.

"The PDS 70 imagery Jason's team captured was among the first tests of the scientific quality produced by Keck's pyramid wavefront sensor," said AO scientist Charlotte Bond, who played a key role in the design and installation of the technology. "It's exciting to see just how precise the new AO system corrects for the atmospheric turbulence of dusty objects like the young stars where protoplanets are expected to reside, allowing for the clearest, sharpest view of baby versions of our solar system."

AURORA, Colo. (May 18, 2020) - Researchers from the University of Colorado School of Medicine have identified a new way that cells in the central nervous system regenerate and repair following damage.

In an article published in the current issue of Nature Neuroscience, scientists from CU found that precisely-timed motor learning stimulates cellular processes to improve recovery after damage to oligodendrocytes, cells that are critical for healthy neurologic function throughout life.

The study uses advanced microscopy and mouse models of multiple sclerosis (MS) to evaluate oligodendrocytes and their precursor cells to better understand how they can be harnessed to restore neuronal function following injury.

"Tissue regeneration following injury or disease is a long sought-after goal, particularly in the adult nervous system," said Ethan G. Hughes, PhD, assistant professor of Cell and Developmental Biology at the CU School of Medicine and a Boettcher Investigator.

Of particular interest in this study, Hughes and his colleagues found that mature oligodendrocytes are able to contribute to repair of the nervous system by generating new myelin sheaths. Myelin sheaths surround nerve fibers and speed transmission of nerve impulses to and from the brain. Identifying the contribution of mature oligodendrocytes to this process is a breakthrough finding that challenges existing scientific orthodoxy.

Hughes and his colleagues found that behavioral training in mice promoted the regeneration of myelin sheaths from newly formed and mature oligodendrocytes to aid in the repair of damage of the nervous system.

Their findings offer a potential new target for therapeutic interventions for patients with neurologic disability, such as those caused by MS, which is a progressive, degenerative disease that affects the ability of the brain to communicate with the rest of the body.

Hughes was awarded a Boettcher Foundation Webb-Waring Biomedical Research Award in 2016 and research grants from the Conrad N. Hilton Foundation, National Multiple Sclerosis Society, National Institutes of Neurological Disorders and Stroke, and Whitehall Foundation to support his laboratory's work. This work was done in collaboration with the laboratory of Cristin Welle, PhD, associate professor of Neurosurgery and Physiology and Biophysics at the CU School of Medicine and a fellow Boettcher Investigator. The current study by Hughes and his colleagues shows that motor learning improves recovery from demyelinating injury through enhanced remyelination.

Today, scientists from all over the world face the task of creating optical switches. These devices will allow for transmitting information in binary code with the help of light, which in the future will be useful for the development of ultrafast optical memory cells. ITMO University scientists have demonstrated how to create, using a femtosecond laser, an all-optical switch based on a metal-organic framework which can be synthesized in vitro and is usually used in chemistry for gas absorption. The research has been published in the journal Angewandte Chemie.

Physicists, engineers and programmers from all over the world are increasingly talking about the prospects of so-called optical memory elements. These might replace modern devices, in which information is processed based on the movement of electrons. It is expected that computing elements operating on photons will work faster, more efficiently, and most importantly, consume less energy. But in order to get closer to bringing these bold plans to life, it is necessary to solve a number of theoretical and engineering problems. One of them is achieving reliable, energy-efficient, and low-cost light control.

"All of today's digital electronics are built on so-called triggers," explains Nikita Kulachenkov, a junior research associate at ITMO University and one of the paper's authors. "These are devices for switching between two states, 0 and 1. For optical devices which might in the future take the place of our electronic devices, we also need a special switch."

One of the options for such a switch comes in the form of metal-organic frameworks (MOFs). This is a class of functional materials which combine the properties of crystal lattice substances and organic compounds. But for the purposes of developing optical computing devices, the most important aspect is that some MOFs contain special photochromic compounds capable of changing their optical properties when exposed to light. This process, however, usually takes place over a relatively long period of time, from several minutes to several days, which puts significant limitations on the practical application of such structures as switchers.

A group of scientists from ITMO University's Russian-French laboratory, headed by Valentin Milichko, decided to take a different path - the researchers used standard metal-organic frameworks that don't contain any photochromic compounds and have for a long time been used in the chemical industry.
"We decided, why not use a group of MOFs that demonstrate the property of changing their structure under external stimuli such as pressure, temperature or others," says Nikita Kulachenkov. "Among these metal-organic frameworks was HKUST-1. It was very well-researched in the field of gas absorption, but no one could ever have thought that its properties, and consequently its structure, could undergo significant changes when exposed to light."

Experiments with HKUST-1 metal-organic frameworks have shown that when subjected to an ultra-short pulse of an infrared laser, this MOF suddenly starts to transmit less light. "The number of photons passing through the MOF decreased by about a hundred times," explains Nikita Kulachenkov. "The switch-over period amounted to several dozen milliseconds. This is two to three orders better than offered by existing MOF-based organic systems."

Physics-wise, this change has the following explanation - the femtosecond impact generated by the infrared laser is enough to, in effect, evaporate the water from the metal-organic framework. This leads to the MOF becoming less transparent for the laser-emitted light. But once you turn off the light, the framework reabsorbs water molecules from the air and returns to its initial state.

In influencing the trajectory of the pandemic stage of an emerging pathogen, a population’s susceptibility to a novel disease is more influential than climate factors like humidity. The results – based on a model informed by climate-dependence of known coronaviruses – may inform researchers’ effort to understand the likely trajectory of the ongoing COVID-19 pandemic, including as summer and its associated temperature and humidity changes, hoped for to bring respite from the pandemic, set in in parts of the world. Preliminary evidence suggests that climate factors like humidity may impact the transmission of SARS-CoV-2. Yet, whether these factors could substantially alter the pandemic trajectory over the remainder of 2020 remains a question, given that a population’s high susceptibility (or low immunity) to the virus is also a core influence. To better understand this, Rachel Baker and colleagues used a climate-driven epidemiological model fitted with U.S. data on four other circulating and seasonal coronaviruses. In simulations of their model in different cities in high latitudes and tropical locations, they found that even in tropical cities, with conditions that should hinder virus transmission, outbreak growth remained significant. Following their analyses, the authors report that while climate effects may drive modest changes to the peak size and duration of the pandemic, summer weather will not likely limit pandemic growth, as the pandemic trajectory is modulated more by population susceptibility to the illness. In a further, preliminary analysis of how non-pharmaceutical control measures (including shelter-at-home orders) influence spread of SARS-CoV-2, the authors report these measures may moderate the pandemic-climate interaction to some extent, by removing susceptible people from the population. The results suggest that population susceptibility remains the driving factor in SARS-CoV-2 spread over summer and suggest that, unless effective control measures are maintained, significant numbers of COVID-19 cases in the coming months are likely even in more humid and warmer climates.

Philadelphia, May 18, 2020 - Genomic selection has become a critical tool for the dairy industry around the world since genomic evaluations were first implemented in the United States and Canada in 2009. The 2019 ADSA Annual Meeting featured the Joint ADSA/Interbull Breeding and Genetics Symposia titled "Ten Years of Genomic Selection" and "Data Pipelines for Implementation of Genomic Evaluation of Novel Traits." Because of genomic selection's importance to dairy science, the Journal of Dairy Science invited the speakers to submit articles and share information from these symposia with a wider audience.

"The rapid uptake of genomic selection has had a dramatic effect on the dairy industry," guest editor Filippo Miglior, PhD, of the Centre for Genetic Improvement of Livestock at the University of Guelph, said. "These two symposia were developed to provide a comprehensive overview of the last 10 years of genomic selection and how genomics has provided the opportunity to develop new data pipelines for novel traits now under selection worldwide."

The symposium "Ten Years of Genomic Selection" started by reviewing progress from the development of the cattle reference genome to modern 50k SNP chips for implementation of genomic evaluation and selection. Once applied only to males for prediction of progeny performance, genomic selection is now widely used to predict future performance of cows and embryos.

Although genomic selection has allowed for rapid acceleration of genetic progress, it has also resulted in a rapid accumulation of homozygosity in the dairy cattle population. Better understanding is needed to ensure that genetic progress is achieved while maintaining genetic variance. The final presenter discussed the development of single-step genomic evaluations and possible reasons for biases in single-step evaluations.

The symposium "Data Pipelines for Implementation of Genomic Evaluation of Novel Traits" highlighted initiatives to pool data across countries or organizations to exploit the potential of accurate genomic evaluation for novel and expensive traits. It started by examining relationships between feed efficiency traits and how those traits should be incorporated into selection indices, followed by discussion of genomic selection in three countries.

A data pipeline was developed for the collection of hoof health data across Canada, which led to the creation and implementation of a single-step genomic evaluation for multiple hoof health traits. In the United States, health evaluations are now included in net merit selection indices so producers can predict which animals will be most resistant to common diseases. Genomic selection has allowed Australia to focus on traits that reduce the environmental impact of the dairy industry and improve the adaptability of dairy cows to climate change.

"Over the last 10 years, dairy scientists have waded through the brave new world of genomics, and resulting discoveries have brought about tremendous gains in the genetic selection and improvement of dairy cattle," editor in chief Paul Kononoff, PhD, of the University of Nebraska-Lincoln, said. "The genetic progress is chronicled in this collection of papers, which describe the never-before-seen application and pairing of traditional bench-top science and quantitative data analysis. The Journal of Dairy Science is honored to publish these papers and excited to see how they spur continued scientific discovery,"

The symposium papers are published as part of the June issue of the Journal of Dairy Science.

Local variations in climate are not likely to dominate the first wave of the COVID-19 pandemic, according to a Princeton University study published May 18 in the journal Science.

The researchers found that the vast number of people still vulnerable to the strain of coronavirus causing the pandemic -- SARS-CoV-2 -- and the speed at which the pathogen spreads means that climate conditions are only likely to make a dent in the current rate of infection.

"We project that warmer or more humid climates will not slow the virus at the early stage of the pandemic," said first author Rachel Baker, a postdoctoral research associate in the Princeton Environmental Institute (PEI). "We do see some influence of climate on the size and timing of the pandemic, but, in general, because there's so much susceptibility in the population, the virus will spread quickly no matter the climate conditions."

The rapid spread of the virus in Brazil, Ecuador, Australia, and other nations in the tropics and the Southern Hemisphere -- where the virus began during the summer season -- provides some indication that warmer conditions will indeed do little to halt the pandemic, Baker said.

"It doesn't seem that climate is regulating spread right now," Baker said. "Of course, we do not yet directly know how temperature and humidity influence the virus' transmission, but we think it is unlikely that these factors could completely halt transmission based on what we see among other viruses."

Experience with other viruses suggests that, without a vaccine or other control measures, COVID-19 will likely only become responsive to seasonal changes after the supply of unexposed hosts is reduced, said co-author Bryan Grenfell, the Kathryn Briger and Sarah Fenton Professor of Ecology and Evolutionary Biology and Public Affairs and associated faculty in PEI.

"Previously circulating human coronaviruses such as the common cold depend strongly on seasonal factors, peaking in the winter outside of the tropics," Grenfell said. "If, as seems likely, the novel coronavirus is similarly seasonal, we might expect it to settle down to become a winter virus as it becomes endemic in the population. Exactly how depends on a lot of complex factors for a given location."

The pandemic's trajectory over the next several months will be influenced by "both human-induced factors -- such as non-pharmaceutical interventions to reduce contact -- as well as fundamental biological uncertainties, such as the strength and duration of immunity following infection," Grenfell said. "As knowledge of the immune response develops, we hope to be able to project its interaction with seasonality more accurately."

Baker and Grenfell conducted the study with second author Wenchang Yang, an associate research scholar in geosciences; Gabriel Vecchi, professor of geosciences and the Princeton Environmental Institute; and C. Jessica Metcalf, assistant professor of ecology and evolutionary biology and public affairs.

The study authors are all affiliated with PEI's Climate Change and Infectious Disease initiative. The same team published a paper in December examining how climate conditions influence annual outbreaks of respiratory syncytial virus (RSV).

For the study in Science, the researchers ran simulations on how the pandemic would respond to various climates across the globe. Having been discovered in late 2019, COVID-19's response to warmer weather is not well known. The researchers instead ran three scenarios based on what is known about the role seasonal variations have on the occurrence of similar viruses.

The first scenario assumed that the novel coronavirus has the same climate sensitivity as influenza, based on a prior model from laboratory studies that highlighted the importance of low humidity to promote spread. In the second and third scenarios, the virus was given the same climate dependence and length of immunity as human coronaviruses OC43 and HKU1, which are two causes of the common cold.

In all three scenarios, climate only became a mitigating factor when large portions of the human population were immune or resistant to the virus.

"The more that immunity builds up in the population, the more we expect the sensitivity to climate to increase," Baker said. "If you run the model long enough, you have a big pandemic and the outbreak settles into seasonal infection. We're assuming that if the same climate drivers apply to COVID-19, this would be the outcome."

The researchers also ran a simulation that accounted for the average impact of control measures such as social distancing. The results suggested that the longer these measures are in place and slow the transmission of COVID-19, the more sensitive the virus becomes to warmer weather.

"The next step is to test our model by comparing future changes in the pandemic curve with detailed measurements of local climate, control measures and other local variables in different climatic regions," Metcalf said. "We also aim to extend our initial model ---- which mainly captures transmission in cities -- to more rural areas."

The study also has broader implications for refining the integration of meteorological information into understanding disease outbreaks, Vecchi said.

"We are currently exploring the extent to which weather and climate predictions can help provide improved information about the likely course of this disease," Vecchi said. "Weather is only one of many factors. A deeper, interdisciplinary understanding of the interplay of multiple factors that impact disease evolution -- disease dynamics, weather and socioeconomic drivers, including mitigation measures undertaken by society --is needed."

When it comes to wine, the chemistry must be right to get the best taste and sensation.

To help winemakers with that chemistry, a team of researchers at Washington State University has made it easier to test the chemical makeup of their red wine to get the vino they're looking for.

In a paper released last month in the journal Molecules, the scientists presented a new model that allows winemakers to get measurements in their wine that previously required difficult, tedious, or expensive testing.

"Some of the testing methods are very difficult for people in a winery's lab to do during harvest," said Jim Harbertson, a WSU associate professor of enology and the corresponding author on the paper. "The industry asked us to come up with alternate ways to get information. We love chemistry, but most people don't want to do that."

The model allows wine labs to do measurements of phenolics that are typically out of reach for most. Phenolics give red wine its important sensory characteristics, like mouthfeel and color. They also provide antioxidants to the wine.

"This is basically a simplification of lengthy tests," Harbertson said. "It took us several years and a huge amount of work and math, but we've corroborated the results of the model and it works well."

So now winemakers can conduct relatively simple tests, run the results through the new WSU-created algorithm, and get accurate predictions on the mouthfeel and color of the wine produced for consumers.

"Technicians and winemakers in a winery lab will have a much easier time doing the work and getting useful results," Harbertson said.

To make it more helpful to winemakers, Harbertson used research funds to make the academic paper, which he co-wrote with WSU colleagues Chris Beaver and Tom Collins, open access, or available to anyone, online. The goal is to help all wineries in Washington and around the country make better wine.

"This is for the people who make the wine that people drink," he said. "This provides winemakers with a new tool for measuring the components of wine and will ultimately help consumers have better wines to drink."

New research from CSHL scientists suggests that cigarette smoke spurs the lungs to make more ACE2 (angiotensin-converting enzyme 2), the protein that the coronavirus responsible for COVID-19 grabs and uses to enter human cells. The findings, reported May 16, 2020 in the journal Developmental Cell, may explain why smokers appear to be particularly vulnerable to severe infections. The analysis also indicates that the change is reversible, suggesting that quitting smoking might reduce the risk of a severe coronavirus infection.

From the early stages of the current pandemic, scientists and clinicians have noted dramatic differences in how people respond to infection with SARS-CoV-2. Most infected individuals suffer only mild illness, if they experience any at all. But others require intensive care when the sometimes-fatal virus attacks. Three groups, in particular, have been significantly more likely than others to develop severe illness: men, the elderly, and smokers.

With most laboratory experiments on hold due to the pandemic, CSHL Fellow Jason Sheltzer and Joan Smith, an engineer at Google, turned to previously published data to seek possible explanations for these disparities. They were curious whether the vulnerable groups might share some key feature related to the human proteins that the coronavirus relies on for infection.

"We started gathering all the data we could find," Sheltzer says, explaining that he and Smith focused first on comparing gene activity in the lungs across different ages, between the sexes, and between smokers and nonsmokers. "When we put it all together and started analyzing it, we saw that both mice that had been exposed to smoke in a laboratory and humans who were current smokers had significant upregulation of ACE2."

While they found no evidence that age or sex impacts ACE2 levels in the lungs, the influence of smoke exposure was surprisingly strong, Sheltzer says. The change appears to be temporary, however: the data revealed that the level of ACE2 in the lungs of people who had quit smoking was similar to that of non-smokers.

Sheltzer, Smith, and colleagues also found that the most prolific producers of ACE2 in the airways are mucus-producing cells called goblet cells. Smoking is known to increase the prevalence of such cells, a change that can protect the airways from irritants but--by amplifying the amount of ACE2 in the lungs--may also increase vulnerability to SARS-CoV-2.

Far below the Earth's surface, about 1,800 miles deep, lies a roiling magmatic region sandwiched between the solid silicate-based mantle and molten iron-rich core: The core-mantle boundary. It's a remnant of olden times, the primordial days about 4.5 billion years ago when the entire planet was molten, an endless sea of magma. Although the region's extreme pressures and temperatures make it difficult to study, it contains clues about the mysterious origin story of the world as we know it.

"We're still trying to piece together how the Earth actually started to form, how it transformed from a molten planet to one with living creatures walking around on its silicate mantle and crust," says Arianna Gleason, a scientist at the Department of Energy's SLAC National Accelerator Laboratory. "Learning about the strange ways materials behave under different pressures can give us some hints."

Now, scientists have developed a way to study liquid silicates at the extreme conditions found in the core-mantle boundary. This could lead to a better understanding of the Earth's early molten days, which could even extend to other rocky planets. The research was led by scientists Guillaume Morard and Alessandra Ravasio. The team, which included Gleason and other researchers from SLAC and Stanford University, published their findings this week in the Proceedings of the National Academy of Sciences.

"There are features of liquids and glasses, in particular silicate melts, that we don't understand," says Morard, a scientist at the University of Grenoble and Sorbonne University in France. "The problem is that molten materials are intrinsically more challenging to study. Through our experiments we were able to probe geophysical materials at the extremely high temperatures and pressures of deep Earth to tackle their liquid structure and learn how they behave. In the future we will be able to use these types of experiments to recreate the first moments of Earth and understand the processes that shaped it."

Hotter than the sun

At SLAC's Linac Coherent Light Source (LCLS) X-ray free-electron laser, the researchers first sent a shockwave through a silicate sample with a carefully tuned optical laser. This allowed them to reach pressures that mimic those at the Earth's mantle, 10 times higher than previously achieved with liquid silicates, and temperatures as high as 6,000 Kelvin, slightly hotter than the surface of the sun.

Next, the researchers hit the sample with ultrafast X-ray laser pulses from LCLS at the precise moment the shockwave reached the desired pressure and temperature. Some of the X-rays then scattered into a detector and formed a diffraction pattern. Just like every person has their own set of fingerprints, the atomic structure of materials is often unique. Diffraction patterns reveal that material fingerprint, allowing the researchers to follow how the sample's atoms rearranged in response to the increase of pressure and temperature during the shockwave. They compared their results to those of previous experiments and molecular simulations to reveal a common evolutionary timeline of glasses and liquid silicates at high pressure.

"It's exciting to be able to gather all these different techniques and get similar results," says SLAC scientist and co-author Hae Ja Lee. "This allows us to find a combined framework that makes sense and take a step forward. It's very comprehensive compared to other studies."

Connecting the atomistic to the planetary

In the future, the LCLS-II upgrade, as well as upgrades to the Matter in Extreme Conditions (MEC) instrument where this research was performed, will allow scientists to recreate the extreme conditions found in the inner and outer core to learn about how iron behaves and the role it plays in generating and shaping Earth's magnetic field.

To follow up on this study, the researchers plan to perform experiments at higher X-ray energies to make more precise measurements of the atomic arrangement of liquid silicates. They also hope to reach higher temperatures and pressures to gain insight into how these processes unfold in planets bigger than Earth, so-called super-Earths or exoplanets, and how the size and location of a planet influences its composition.

"This research allows us to connect the atomistic to the planetary," Gleason says. "As of this month, more than 4,000 exoplanets have been discovered, about 55 of which are positioned in the habitable zone of their stars where it's possible for liquid water to exist. Some of those have evolved to the point where we believe there's a metallic core that could generate magnetic fields, which shield planets from stellar winds and cosmic radiation. There are so many pieces that need to fall into place for life to form and be sustained. Making the important measurements to better understand the construction of these planets is crucial in this age of discovery."

Sometimes scientists begin research and find exactly what they expected. Other times they discover something unexpected. Such was the case for a group of scientists studying plant stress responses who stumbled upon a new mutation.

"The discovery of this mutation was actually a surprise," said first author Matt Neubauer. "And by trying to better understand this new mutation, and what effect it had on plant stress responses, we uncovered new information about how different plant stress regulators function."

These scientists were working on a stress-regulating gene known as ENHANCED DISEASE RESISTANCE1 (EDR1) when they identified a new gain-of-function mutation in a second gene named PHYTOALEXIN DEFICIENT4 (PAD4), a gene that regulates plant responses to biotic stress.

"PAD4 has been studied for a long time, but this is the first time a gain-of-function mutation has been identified," said Neubauer. "We named this mutation pad4-13. It occurred as a spontaneous mutation in the edr1-mutant background and enhances cell death during fungal infection. We believe it was selected during backcrossing of the original edr1 mutant because it enhances the visible edr1 mutant phenotype, powdery mildew-induced cell death."

They also found that this mutation makes the PAD4 protein more active, which in turn enables plants to have a stronger resistance response to pathogen infection. This is unique, as all previously discovered pad4 mutations are loss-of-function and make plants more susceptible to bacterial, oomycete, and fungal pathogens.

The scientists also discovered one more significant detail about plant stress regulators. It has been established that PAD4 interacts with a partner protein known as EDS1 (for ENHANCED DISEASE SUSCEPTIBILITY) to turn on plant stress responses. Through this research, scientists found that EDR1 blocks PAD4 from interacting with EDS1, which could provide a way to turn off or dampen stress responses.

"The discovery that EDR1 may directly regulate PAD4 enhances our knowledge of how plants control stress responses," said Neubauer, while acknowledging that there is still more to learn. "Ultimately we were unable to show how this new mutation makes PAD4 more active."

Enzymes Edit SARS-CoV-2 RNA in the Body, Perhaps Fueling the Virus' Evolution

Two human deaminase enzymes edit the RNA of the SARS-CoV-2 virus when it enters a patient's body, with implications for the evolution of the virus and the spread of the infection, according to a new study. The findings provide a first step towards understanding how RNA editing affects the replication of the virus responsible for the current COVID-19 pandemic - a potentially significant process, since post-infection viral genome editing in the host is suspected to have influenced the evolution of other viruses, including Rubella. Salvatore Di Giorgio and colleagues note that by comparing sites in the SARS-CoV-2 genome that are edited with those that are mutated, scientists may be able to identify strategies to target the virus with new therapies. Mammals express two different deaminase families - ADARs and APOBECs - that alter the basic nucleotide building blocks of viral RNA (or, in the latter case, sometimes DNA intermediates) by removing an amino group from their nucleobase components. However, it has not been known whether this innate virus-counteracting process operates against coronaviruses. To assess whether RNA editing may be involved in the body's response to SARS-CoV-2 infections, Di Giorgio et al. analyzed single nucleotide variants in RNA sequencing datasets from fluid extracted from the lungs of patients diagnosed with COVID-19. While they observed low numbers of mutation events, the researchers did identify nucleotide changes (adenosine to inosine, and cytosine to uracil) that may be attributed to RNA editing. To better understand whether RNA editing could be the cause for mutations acquired through evolution, the researchers also compared genomes from SARS-CoV-2, MERS-CoV, and SARS-CoV. They suggest that a sizable percentage of mutations in each of these coronavirus strains may have been caused by deaminase enzymes. The authors speculate that, if these enzymes are indeed involved in the human response to SARS-CoV-2 infection, a genetic variation that affects two forms of APOBEC - known to be common in the Chinese population - could play a role in the spread of the infection.

TALLAHASSEE, Fla. -- A Florida State University researcher has used new detection methods to identify 85 previously unknown submarine landslides that occurred in the Gulf of Mexico between 2008 and 2015, leading to questions about the stability of oil rigs and other structures, such as pipelines built in the region.

Assistant Professor Wenyuan Fan in the Department of Earth, Ocean and Atmospheric Science has published a new paper in the journal Geophysical Research Letters that identifies these landslides and the risks they pose to coastal communities.

"The observed landslides suggest a possible tsunami hazard for coastal communities along the Gulf of Mexico and that seabed infrastructure in the Gulf of Mexico, including oil platforms and pipelines, is also at risk from the landslides," Fan said.

Fan and his colleagues measured data from seismic stations across the United States. They found that out of the 85 landslides they identified, 10 occurred spontaneously without preceding earthquakes. The other 75 occurred almost instantly after the passage of surface waves caused by distant earthquakes. Some of these were considered rather small earthquakes, Fan added.

The finding was a surprise for Fan and his colleagues, he noted. In trying to better understand lesser-known earthquake processes, he had designed a method to capture earthquake data that would help him get a better look at continuous waveforms. That led him to seismic sources in the Gulf of Mexico.

"There are few active faults in the Gulf, and the seismicity is scarce in the region," he said. "This puzzled me and concerned me because we live close to the Gulf. With the question and the concern, I looked into the details of these seismic sources and eventually concluded that they are likely to be submarine landslides."

Fan said currently he and his colleagues do not have any real-time data related to damage from these events and that most of the landslides were in the deep-water region of the Gulf. The ability to detect and locate these submarine landslides suggests that scientists may be able to adapt researchers' methods for hazard monitoring in the future though.

It is not uncommon to find aluminum in municipal water systems. It's part of a treatment chemical used in some water treatment processes. Recently, however, it has been discovered in lead scale, deposits that form on lead water pipes.

The aluminum presence in pipes is both unsurprising and, in the quantities researchers saw in water pipes, not a health concern, according to Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering in the McKelvey School of Engineering at Washington University in St. Louis. But no one had looked at how it might affect the larger municipal system.

In particular, Giammar wanted to find out, "What is that aluminum doing to the behavior of the lead in the scale?" As long as the lead is bound to the scale, it doesn't enter the water system.

Giammar and a team ran several experiments and found that, in a lab setting, aluminum does have a small but important effect on lead's solubility under certain conditions. Their results were published in late April in Environmental Science & Technology. The paper was selected as "ACS Editor's Choice" by the American Chemical Society, which makes it available to the public for free.

The experiments were carried out in large part by visiting PhD student Guiwei Li, who was able to complete the work during his brief stay at Washington University before returning to the Chinese Academy of Sciences.

In simplified models, the researchers took a look at how phosphate, aluminum and a combination of the two, affected a strip of lead in a jar of water with a composition close to that of water found in many water systems. The aim: to better understand lead's solubility, or the amount that would dissolve and make its way into the water when impacted by those chemicals.

In the jar in which only aluminum was added, there was no effect on the solubility of the lead strip; lead had dissolved into the water at a concentration of about 100 micrograms per liter.

In the jar in which only phosphate was added, the concentration of lead in the water decreased from about 100 micrograms per liter to less than one.

In the jar in which both aluminum and phosphate were added, the concentration of lead in the water decreased from about 100 micrograms per liter to about 10 micrograms per liter.

Ten micrograms of lead per liter of water is still below drinking water standards, Giammar said, but it's still more lead in the water than was seen in the jar without aluminum. "This tells us what our next experiment should be," he said. His lab will do these experiments with real lead pipes, as they have done in the past.

"This showed us things that were surprising," he said. "Some people would have thought that aluminum wasn't doing anything because it's inert. But then in our work, we saw that it actually affects lead solubility."

Below please find a summary and link(s) of new coronavirus-related content published today in Annals of Internal Medicine. The summary below is not intended to substitute for the full article as a source of information. A collection of coronavirus-related content is free to the public at http://go.annals.org/coronavirus.

1. Tocilizumab for Hemophagocytic Syndrome in a Kidney Transplant Recipient with COVID-19

Studies suggest that many patients with COVID-19 and acute respiratory distress syndrome experience a cytokine storm characterized by fever; hyperferritinemia; and a massive release of inflammatory cytokines, including interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant proteins. These findings led to the hypothesis that biological agents targeting specific cytokine or inflammatory pathways may improve the respiratory outcomes of patients with the most severe forms of COVID-19. Researchers from the University Hospital of Toulouse; Toulouse, France, tested this hypothesis on a severely ill patient on a ventilator for COVID-19. They treated the patient with tocilizumab as salvage therapy, instead of etoposide, and the patient improved dramatically. Read the full text: https://www.acpjournals.org/doi/10.7326/L20-0419.

Media contacts: A PDF for this article is not yet available. Please click the link to read full text. The lead author, Stanislas Faguer, MD, PhD, can be reached at faguer.s@chu-toulouse.fr.