Tech

Chronic pain is one of the most important health priorities of the 21st century, with a socioeconomic cost that may far exceed other most other medical problems. It is the leading reason why people stop working prematurely, and a leading cause of loss of independence in the elderly leading to requirements for care. And the magnitude of the problem continues to increase as society ages. The lack of effective drugs for pain has led to an urgency to develop new treatments, with technology-based approaches being an potentially important avenue for innovation.

A new approach to treating a range of neurological and psychiatric treatments is Decoded Neurofeedback (DecNef), in which patients aim to control how information is encoded in their brain using neurofeedback of their brain activity measured using functional neuroimaging. The AMED Nou-Pro project has been exploring applications of DecNef to several conditions, and here we report a preliminary study into the feasibility of using DecNef to control pain.

The study, published in the forthcoming issue of Current Biology, is a preclinical study that aimed to see if pain is potentially controllable by DecNef. We designed a new type of DecNef paradigm, in which volunteers had to try and make the pain 'clearer' in their mind, to help a computer read how much pain they were in by studying their brain activity. If the computer could read their pain well, it could work out how to give them less pain later in the experiment.

We found subjects were not easily able to directly control their pain activity in the brain, suggesting that conventional DecNef for pain might be difficult. But instead we found that DecNef had a different effect: it seemed to be boosting the brains' natural ability to control pain - by enhancing a system caused the 'endogenous pain control system'. This system is the system that normally tunes how much pain is felt, and allows us to naturally reduce our pain in a wide variety of everyday situations. Importantly, this system seems to be dysfunctional in chronic pain, and so DecNef might provide a way to boost this system to treat pain.

Perovskite and organic solar cells are promising options for future generations of solar cells. Over recent years, their efficiency has rapidly caught up with that of conventional silicon-based cells.

"The best perovskite solar cells currently achieve efficiency levels of 25 percent," says Peter Mueller-Buschbaum, Professor of Functional Materials at the TUM Department of Physics. "These thin solar cells, less than one micrometer thick, applied to ultra-thin, flexible synthetic sheet, are extremely lightweight. They can therefore produce nearly 30 watts per gram."

Manufacture at room temperature

This is only possible thanks to a decisive advantage of the new solar cells: Production of silicon solar cells requires very high temperatures and elaborate processes. Perovskite cells and organic semiconductors, on the other hand, can be manufactured at room temperature from solution.

"These organic solutions are very easy to process," explains the lead author Lennart Reb. "Thus the technologies open up new fields of application in which conventional solar cells were simply too unwieldy or too heavy - and that also applies far beyond the aerospace sector."

Test flight into space

Two different types of organic and perovskite solar cells were tested in space for the first time on a research flight as part of the MAPHEUS 8 program at the European Space and Sounding Rocket Range in Kiruna, Sweden. The rocket reached a height of nearly 240 kilometers.

"Our MAPHEUS program allows us rapidly to implement experiments in a zero-gravity environment, offering exciting research findings," says Professor Andreas Meyer, co-author and Head of the DLR Institute of Materials Physics in Space. "This time it went particularly quick: it took us less than a year to progress from the initial idea to the maiden flight of the solar cells as part of the MAPHEUS 8 program."

Power generation under exeptional conditions

"Electrical measurements during the flight and the evaluation after recovery of the rocket showed that perovskite and organic solar cells can achieve their potential in terms of expected performance in orbit height," reports Professor Mueller-Buschbaum. "Our measurements are therefore of great scientific value."

The solar cells also generated electrical energy under diffuse incidence of light. "Cells turned away from the sunlight, which received only sparse lighting exclusively from the earth during the flight, still supplied electricity," says Reb.

Due to their much thinner thickness, the new solar cells could therefore also be used in much dimmer light, for example on missions to the outer solar system on which the sun is too weak for conventional space solar cells.

According to DLR material scientist Andreas Meyer, "it would not be the first time that innovations are first established as space technologies but go on to be used around the world in other sectors. One reason for this is probably the very strict requirements that space places on all technical components."

Researchers have developed a new test that can diagnose COVID-19 in just 20 minutes.

The findings, published in the Journal of Medical Microbiology, show the rapid molecular test called N1-STOP-LAMP, is 100% accurate in diagnosing samples containing SARS-CoV-2 at high loads.

The test is highly accurate and easy to use, making it a prime candidate for use in settings with limited testing capabilities. The method involves using a small portable machine, which can reliably detect SARS-CoV-2 from just one nasal swab. "In the race to control the COVID-19 pandemic, access to rapid, precision diagnostics is key. We have developed an alternative COVID-19 molecular test that can be readily deployed in settings where access to standard laboratory testing is limited or where ultra-rapid result turnaround times are needed" said University of Melbourne Professor Tim Stinear, Laboratory Head at the Doherty Institute.

This new test uses only one tube and involves only a single step, making it more efficient and lower cost than many of the current tests for SARS-CoV-2. The N1-STOP-LAMP method was found to be 100% accurate and correctly identified 87% of tests as positive when used to assess 157 confirmed-positive samples. The results were fast, with an average time-to-positive of 14 minutes for 93 of those clinical samples.

"We see this kind of technology having benefit in settings liked aged care facilities, or overseas laboratories with limited resources and equipment," Professor Stinear said. "The test requires a small shoebox-sized machine, as well as reagents, but everything is portable."

"STOP-LAMP is what's referred to as a 'near care' test, it is not intended to replace the current gold standard PCR testing. It's a robust diagnostic test for the specific and rapid detection of COVID-19. But it's important to note however, it trades some detection sensitivity for speed and ease-of-use".

Researchers from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences found that the projected uncertainty of the precipitation increase over global land monsoon regions by the Coupled Model Intercomparison Project Phase 6 (CMIP6) models was mainly due to the spread of circulation changes across models.

Their study was published in Geophysical Research Letters on June 9.

Billions of people living in global land monsoon regions rely on freshwater resources from monsoon rainfall. Monsoon rainfall may cause drought and flood disasters, influencing the livelihood of population. A reliable and accurate projection is needed.

In the CMIP6, four new projected scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) reflect a set of alternative futures of social and economic development.

The researchers found that the global land monsoon summer precipitation increased under all scenarios, by about 2.54% and 5.75% in the lowest (SSP1-2.6) and highest (SSP5-8.5) emission scenarios, respectively. The enhancement was caused by thermodynamic responses due to increased moisture.

"Global land monsoon region is dominated by ascending motion in summer. The increase moisture caused by global warming can result in the increase of vertical moisture advection and contribute to the wetting trend in summer, which is also called wet-get-wetter mechanism," said Ziming Chen from IAP, the first author of the paper.

Meanwhile, the model spread in the projection was larger for higher emission scenarios. In addition, such spread was also larger than that in the previous CMIP projection. More importantly, the spread was related to the uncertainty of monsoon circulation changes.

Circulation changes should be related to the changes of sea surface temperature (SST). But in an experiment which prescribes a uniform SST warming, the spread in the monsoon circulation changes is still evident.

"This study emphasizes the importance of reliable prediction of circulation changes, to ensure that future projections of global land monsoon are suitable for use by policy makers," added Chen.

It is known that different regions of the brain help us prioritize information so we can efficiently process visual scenes. A new study by a team of neuroscientists has discovered that one specific region, the occipital cortex, plays a causal role in piloting our attention to manage the intake of images.

The work, which appears in the latest issue of the journal Current Biology, relies on a method, transcranial magnetic stimulation (TMS), which helps illuminate this dynamic.

"By briefly disrupting cortical excitability of the occipital cortex with TMS we could extinguish the known effects of involuntary, or exogenous, covert spatial attention, and thus reveal a causal link between the occipital cortex and the effect of covert attention on vision," explains Marisa Carrasco, a professor of psychology and neural science at New York University and the senior author of the paper.

"This is a surprising finding as most previous research shows that other areas of the brain--the frontal and parietal cortex--help us in selectively processing many images that come our way, but this research reveals that the occipital cortex also plays a critical functional role," adds Antonio Fernández, an NYU doctoral student and first author of the paper.

In our daily lives, we are bombarded with an overwhelming amount of sensory information, notably visuals, from as big as skyscrapers to as small as computer screens. In spite of this, we have the impression of effortlessly understanding what we see, unaware of the complex mechanisms that, in a kind of cognitive triage, help us prioritize the information that we process. It's been long shown that the processing of visual information and its accompanying neural computations consume a great deal of energy, which is finite and must be managed.

One of the ways we achieve this is through covert spatial attention, which enables us to select a certain location of a visual scene and prioritize its processing and guide behavior, even without moving our eyes to that location (which is why it is called covert).

Covert attention, whether voluntary (endogenous) or involuntary (exogenous), is a trade-off process--it benefits visual processing at the attended location at the expense of processing elsewhere.

Earlier neuroimaging and electrophysiological studies have shown that visual areas in the occipital cortex, located in the back of the brain, are part of the attention cortical networks, but it was unknown whether this region is necessary in the prioritizing of visual content.

Because of its well-established role in vision, Fernández and Carrasco specifically sought to determine if the occipital cortex played a causal role in guiding involuntary (exogenous) covert attention.

To do so, they conducted a series of experiments with human observers and used TMS to manipulate and briefly alter cortical excitability in the occipital area.

The authors asked the participants to make an orientation judgement by determining if an image was tilted right or left on a computer screen. They also manipulated participants' covert attention with an additional image--a cue (small line) that appeared on the screen prior to stimuli presentation to automatically attract attention to its location. One stimulus appeared left and the other stimulus appeared right off center, while observers fixated at a central point. The cortical representation of one of the two stimuli was briefly disrupted using TMS. In some trials, "valid trials," the cue indicated the stimulus location observers should respond to; in other trials, "invalid trials," the peripheral cue indicated the other stimulus location. In neutral trials, both stimuli were cued.

This design allowed the investigators to record responses at the attended and unattended locations with and without stimulation. Without TMS, behavioral responses reflected the typical performance benefits (valid trials compared to neutral trials) and costs (invalid trials compared to neutral trials) at attended and unattended locations, respectively. However, with TMS disrupting activity in the occipital cortex, the responses were the same regardless of the nature of the attentional cue, and both behavioral benefits and costs were eliminated.

From Sinatra to Katy Perry, celebrities have long sung about the power of a smile - how it picks you up, changes your outlook, and generally makes you feel better. But is it all smoke and mirrors, or is there a scientific backing to the claim?

Groundbreaking research from the University of South Australia confirms that the act of smiling can trick your mind into being more positive, simply by moving your facial muscles.

With the world in crisis amid COVID-19, and alarming rises of anxiety and depression in Australia and around the world, the findings could not be more timely.

The study, published in Experimental Psychology, evaluated the impact of a covert smile on perception of face and body expressions. In both scenarios, a smile was induced by participants holding a pen between their teeth, forcing their facial muscles to replicate the movement of a smile.

The research found that facial muscular activity not only alters the recognition of facial expressions but also body expressions, with both generating more positive emotions.

Lead researcher and human and artificial cognition expert, UniSA's Dr Fernando Marmolejo-Ramos says the finding has important insights for mental health.

"When your muscles say you're happy, you're more likely to see the world around you in a positive way," Dr Marmolejo-Ramos says.

"In our research we found that when you forcefully practise smiling, it stimulates the amygdala - the emotional centre of the brain - which releases neurotransmitters to encourage an emotionally positive state.

"For mental health, this has interesting implications. If we can trick the brain into perceiving stimuli as 'happy', then we can potentially use this mechanism to help boost mental health."

The study replicated findings from the 'covert' smile experiment by evaluating how people interpret a range of facial expressions (spanning frowns to smiles) using the pen-in-teeth mechanism; it then extended this using point-light motion images (spanning sad walking videos to happy walking videos) as the visual stimuli.

Dr Marmolejo-Ramos says there is a strong link between action and perception.

"In a nutshell, perceptual and motor systems are intertwined when we emotionally process stimuli," Dr Marmolejo-Ramos says.

"A 'fake it 'til you make it' approach could have more credit than we expect."

"Blue whirls" -- small, spinning blue flames that produce almost no soot when they burn -- have attracted great interest since their discovery in 2016, in part because they represent a potential new avenue for low-emission combustion.

Now, a team of researchers at the University of Maryland and Texas A&M University has identified how these intriguing whirls are structured. Their findings were published in the peer-reviewed journal Science Advances on August 12, 2020.

The team includes now-graduated UMD aerospace engineering PhD students Joseph D. Chung and Xiao Zhang, working with Professor Elaine S. Oran, who is TEES Eminent Research Professor at Texas A&M University and previously Glenn L. Martin Professor at UMD's A. James Clark School of Engineering, and Dr. Carolyn R. Kaplan of the Department of Aerospace Engineering at UMD.

Using high-performance computing methods at the University of Maryland's Deepthought2 cluster and other computer systems, the researchers showed that a blue whirl is composed of three different flames -- a diffusion flame and a premixed rich and lean flame -- all of which meet in a fourth structure, a triple flame that appears as a whirling blue ring. The researchers also found that vortex breakdown -- a fluid instability that occurs in swirling flows -- enables the blue-whirl structure to emerge.

"The flame and flow structure revealed by the simulations serves as a fundamental base to further investigate how to create the blue whirl in a more controlled way," said Zhang. "It leads pathways to answering more complex questions."

"Examples of such questions are: How can we create blue whirls on different scales? Can we bypass the transitional, sooty, dangerous fire whirl stage and create the stable and clean blue whirl directly? The newly developed algorithms and models also provide great exploring tools to find these answers," Chung said.

Blue whirls were initially discovered in 2016 by Oran, working with Professor Michael Gollner, previously of the Department of Fire Protection Engineering and now at University of California, Berkeley, and Professor Huahua Xiao, previously in the Department of Aerospace Engineering at UMD and now at the University of Science and Technology in Hefei, China. At the time, they were investigating the behavior of a known phenomenon -- the fire whirl, also known as fire tornado -- when it occurs on a water base.

"Blue whirls evolve from traditional yellow fire whirls," Oran said. "The yellow color is due to radiating soot particles, which form when there is not enough oxygen to burn the fuel completely."

"Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn. We now know that blue whirl will burn all of the fuel available as it exits a burner or from a surface."

An international task force, including two University of Massachusetts Amherst computer scientists, concludes in new research that mobile health (mHealth) technologies are a viable option to monitor COVID-19 patients at home and predict which ones will need medical intervention.

The technologies - including wearable sensors, electronic patient-reported data and digital contact tracing - also could be used to monitor and predict coronavirus exposure in people presumed to be free of infection, providing information that could help prioritize diagnostic testing.

The 60-member panel, with members from Australia, Germany, Ireland, Italy, Switzerland and across the U.S., was led by Harvard Medical School associate professor Paolo Bonato, director of the Motion Analysis Lab at Spaulding Rehabilitation Hospital in Boston. UMass Amherst task force members Sunghoon Ivan Lee and Tauhidur Rahman, both assistant professors in the College of Information and Computer Sciences, focused their review on mobile health sensors, their area of expertise.

The team's study, "Can mHealth Technology Help Mitigate the Effects of the COVID 19 Pandemic?" was published Wednesday in the IEEE Open Journal of Engineering in Medicine and Biology.

"To be able to activate a diverse group of experts with such a singular focus speaks to the commitment the entire research and science community has in addressing this pandemic," Bonato says. "Our goal is to quickly get important findings into the hands of the clinical community so we continue to build effective interventions."

The task force brought together researchers and experts from a range of fields, including computer science, biomedical engineering, medicine and health sciences. "A large number of researchers and experts around the world dedicated months of efforts to carefully reviewing technologies in eight different areas," Lee says.

"I hope that the paper will enable current and future researchers to understand the complex problems and the limitations and potential solutions of these state-of-the-art mobile health systems," Rahman adds.

The task force review found that smartphone applications enabling self-reports and wearable sensors enabling physiological data collection could be used to monitor clinical workers and detect early signs of an outbreak in hospital or healthcare settings.

Similarly, in the community, early detection of COVID-19 cases could be achieved by building on research that showed it is possible to predict influenza-like illness rates, as well as COVID-19 epidemic trends, by using wearable sensors to capture heart rate and sleep duration, among other data.

Lee and Rahman, inventors of mobile health sensors themselves, reviewed 27 commercially available remote monitoring technologies that could be immediately used in clinical practices to help patients and frontline healthcare workers monitor symptoms of COVID-19.

"We carefully investigated whether the technologies could 'monitor' a number of obvious indicators and symptoms of COVID-19 and whether any clearance or certification from health authorities was needed," Lee says. "We considered ease of use and integration flexibility with existing hospital electronic systems. Then we identified 12 examples of technologies that could potentially be used to monitor patients and healthcare workers."

Bonato says additional research will help expand the understanding of how best to use and develop the technologies. "The better data and tracking we can collect using mHealth technologies can help public health experts understand the scope and spread of this virus and, most importantly, hopefully help more people get the care they need earlier," he says.

The paper concludes, "When combined with diagnostic and immune status testing, mHealth technology could be a valuable tool to help mitigate, if not prevent, the next surge of COVID-19 cases."

North Carolina State University researchers have demonstrated a new technique for creating ultrasound images. The new approach is substantially simpler than existing techniques and could significantly drive down technology costs.

"Conventional ultrasound devices have a receiver that detects ultrasonic waves and converts them into an electrical signal, which is then sent to a computer that processes the signal and converts it into an image," says Xiaoning Jiang, co-corresponding author of a paper on the work and a Duncan Distinguished Professor of Mechanical and Aerospace Engineering at NC State. "We've created a device that effectively eliminates the electrical signal processing altogether."

Specifically, the researchers have developed a receiver that incorporates a piezoelectric crystal and an organic light-emitting diode (OLED). When an ultrasonic wave hits the crystal, it produces voltage, which causes the OLED to light up. In other words, the image appears on the OLED screen, which is built into the receiver itself.

"Our prototype is a proof-of-concept, so we designed it with an OLED array that is 10 pixels by 10 pixels; the resolution isn't great," says Franky So, co-corresponding author of the study. "However, I can easily make it 500 pixels by 500 pixels, boosting the resolution substantially." So is the Walter and Ida Freeman Distinguished Professor of Materials Science and Engineering at NC State.

"Conventional ultrasound imaging probes can cost upward of $100,000 because they contain thousands of transducer array elements, which drives up manufacturing costs," So says. "We can make ultrasound receiver-display units for $100 or so."

"This is really a completely new field for ultrasound, so we're only beginning to explore the potential applications," Jiang says. "However, there are obvious near-term applications, such as non-destructive testing, evaluation and inspections in the context of structural health monitoring."

NASA-NOAA's Suomi NPP satellite provided a night-time image of Elida in the Eastern Pacific Ocean that helped confirm the storm had weakened to a post-tropical cyclone.

What is a Post-tropical Cyclone?

The National Hurricane Center (NHC) defines a post-tropical cyclone as a former tropical cyclone. This generic term describes a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can continue carrying heavy rains and high winds. Note that former tropical cyclones that have become fully extratropical... as well as remnant low pressure areas... are two classes of post-tropical cyclones.

NASA's Night-Time View of Elida's Transition

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a night-time image of Elida on Aug. 12 at 10 p.m. PDT (Aug. 13 at 0500 UTC). The imagery showed that Elida was still devoid of strong thunderstorms. The image was created using the NASA Worldview application.

Two hours earlier, NOAA's National Hurricane Center (NHC) noted, "Elida has been devoid of deep convection for more than 12 hours, and since it is over sea surface temperatures of 22 to 23 degrees Celsius (71.6 to 73.4 degrees Fahrenheit), it is unlikely that organized deep convection will return.  As a result, the system has become a post-tropical cyclone, and this will be the last NHC advisory on Elida."

Tropical cyclones require warm sea surface temperatures of at least 26.6 degrees Celsius (80 degrees Fahrenheit) to maintain strength and continue building the thunderstorms that make up a tropical cyclone.

Elida's Last Advisory

At 11 p.m. EDT on Aug. 12 (0300 UTC on Aug. 13), the National Hurricane Center (NHC) issued the final advisory on Elida. At that time, it was located near latitude 24.4 degrees north and longitude 120.2 degrees west. That is about 395 miles (635 km) southwest of Punta Eugenia, Mexico.

The post-tropical cyclone is moving toward the northwest near 9 mph (15 kph).  A northwestward or north-northwestward motion at a slower forward speed is expected through Thursday. Maximum sustained winds have decreased to near 40 mph (65 kph) with higher gusts. The estimated minimum central pressure is 1004 millibars.

Additional weakening is expected during the next day or so, and the remnant low is forecast to dissipate early Friday.

About NASA's EOSDIS Worldview

NASA's Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks "right now."

NASA Researches Earth from Space

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America's leadership in space and scientific exploration.

Observations by NASA's Hubble Space Telescope are showing that the unexpected dimming of the supergiant star Betelgeuse was most likely caused by an immense amount of hot material ejected into space, forming a dust cloud that blocked starlight coming from Betelgeuse's surface.

Hubble researchers suggest that the dust cloud formed when superhot plasma unleashed from an upwelling of a large convection cell on the star's surface passed through the hot atmosphere to the colder outer layers, where it cooled and formed dust grains. The resulting dust cloud blocked light from about a quarter of the star's surface, beginning in late 2019. By April 2020, the star returned to normal brightness.

Betelgeuse is an aging, red supergiant star that has swelled in size due to complex, evolving changes in its nuclear fusion furnace at the core. The star is so huge now that if it replaced the Sun at the center of our solar system, its outer surface would extend past the orbit of Jupiter.

The unprecedented phenomenon for Betelgeuse's great dimming, eventually noticeable to even the naked eye, started in October 2019. By mid-February 2020, the monster star had lost more than two-thirds of its brilliance.

This sudden dimming has mystified astronomers, who scrambled to develop several theories for the abrupt change. One idea was that a huge, cool, dark "star spot" covered a wide patch of the visible surface. But the Hubble observations, led by Andrea Dupree, associate director of the Center for Astrophysics | Harvard & Smithsonian (CfA), Cambridge, Massachusetts, suggest a dust cloud covering a portion of the star.

Several months of Hubble's ultraviolet-light spectroscopic observations of Betelgeuse, beginning in January 2019, yield a timeline leading up to the darkening. These observations provide important new clues to the mechanism behind the dimming.

Hubble captured signs of dense, heated material moving through the star's atmosphere in September, October, and November 2019. Then, in December, several ground-based telescopes observed the star decreasing in brightness in its southern hemisphere.

"With Hubble, we see the material as it left the star's visible surface and moved out through the atmosphere, before the dust formed that caused the star to appear to dim," Dupree said. "We could see the effect of a dense, hot region in the southeast part of the star moving outward.

"This material was two to four times more luminous than the star's normal brightness," she continued. "And then, about a month later, the south part of Betelgeuse dimmed conspicuously as the star grew fainter. We think it is possible that a dark cloud resulted from the outflow that Hubble detected. Only Hubble gives us this evidence that led up to the dimming."

The team's paper will appear online Aug. 13 in The Astrophysical Journal.

Massive supergiant stars like Betelgeuse are important because they expel heavy elements such as carbon into space that become the building blocks of new generations of stars. Carbon is also a basic ingredient for life as we know it.

Tracing a Traumatic Outburst

Dupree's team began using Hubble early last year to analyze the behemoth star. Their observations are part of a three-year Hubble study to monitor variations in the star's outer atmosphere. Betelgeuse is a variable star that expands and contracts, brightening and dimming, on a 420-day cycle.

Hubble's ultraviolet-light sensitivity allowed researchers to probe the layers above the star's surface, which are so hot -- more than 20,000 degrees Fahrenheit -- they cannot be detected at visible wavelengths. These layers are heated partly by the star's turbulent convection cells bubbling up to the surface.

Hubble spectra, taken in early and late 2019, and in 2020, probed the star's outer atmosphere by measuring magnesium II (singly ionized magnesium) lines. In September through November 2019, the researchers measured material moving about 200,000 miles per hour passing from the star's surface into its outer atmosphere.

This hot, dense material continued to travel beyond Betelgeuse's visible surface, reaching millions of miles from the seething star. At that distance, the material cooled down enough to form dust, the researchers said.

This interpretation is consistent with Hubble ultraviolet-light observations in February 2020, which showed that the behavior of the star's outer atmosphere returned to normal, even though visible-light images showed that it was still dimming.

Although Dupree does not know the outburst's cause, she thinks it was aided by the star's pulsation cycle, which continued normally though the event, as recorded by visible-light observations. The paper's co-author, Klaus Strassmeier, of the Leibniz Institute for Astrophysics Potsdam, used the institute's automated telescope called STELLar Activity (STELLA), to measure changes in the velocity of the gas on the star's surface as it rose and fell during the pulsation cycle. The star was expanding in its cycle at the same time as the upwelling of the convective cell. The pulsation rippling outward from Betelgeuse may have helped propel the outflowing plasma through the atmosphere.

Dupree estimates that about two times the normal amount of material from the southern hemisphere was lost over the three months of the outburst. Betelgeuse, like all stars, is losing mass all the time, in this case at a rate 30 million times higher than the Sun.

Betelgeuse is so close to Earth, and so large, that Hubble has been able to resolve surface features - making it the only such star, except for our Sun, where surface detail can be seen.

Hubble images taken by Dupree in 1995 first revealed a mottled surface containing massive convection cells that shrink and swell, which cause them to darken and brighten.

A Supernova Precursor?

The red supergiant is destined to end its life in a supernova blast. Some astronomers think the sudden dimming may be a pre-supernova event. The star is relatively nearby, about 725 light-years away, which means the dimming would have happened around the year 1300. But its light is just reaching Earth now.

"No one knows what a star does right before it goes supernova, because it's never been observed," Dupree explained. "Astronomers have sampled stars maybe a year ahead of them going supernova, but not within days or weeks before it happened. But the chance of the star going supernova anytime soon is pretty small."

Dupree will get another chance to observe the star with Hubble in late August or early September. Right now, Betelgeuse is in the daytime sky, too close to the Sun for Hubble observations. But NASA's Solar Terrestrial Relations Observatory (STEREO) has taken images of the monster star from its location in space. Those observations show that Betelgeuse dimmed again from mid-May to mid-July, although not as dramatically as earlier in the year.

Dupree hopes to use STEREO for more follow-up observations to monitor Betelgeuse's brightness. Her plan is to observe Betelgeuse again next year with STEREO when the star has expanded outward again in its cycle to see if it unleashes another petulant outburst.

Natural mixing of lake waters may resuspend contaminants deposited in a catastrophic mine spill six years ago, according to a new paper led by a University of Alberta scientist.

The results show that the turbidity, or cloudiness, in portions of British Columbia's Quesnel Lake increases each spring and fall when the lake mixes from top to bottom in a natural process called turnover. The source of the turbidity appears to be the resuspension of spill-related material from the bottom of the lake, raising concerns about contaminants being reintroduced to the water column.

On August 4, 2014, a tailings dam containing mine waste from the Mount Polley copper and gold mine failed. "The catastrophic tailings spill dumped 18 million cubic metres of waste water and sediments into the West Basin of Quesnel Lake," explained Andrew Hamilton, postdoctoral fellow in the Department of Earth and Atmospheric Sciences and lead author on the paper. "At the time, it was the largest mine-related spill ever documented."

Since 2014, Hamilton and an interdisciplinary group of scientists from the University of British Columbia (UBC), the University of Northern British Columbia (UNBC), and Fisheries and Oceans Canada (DFO) have monitored the effects of the spill. This study presents results from 2014 through 2017.

"During the first turnover after the spill, mixing brought suspended sediment to the surface, turning the previous clear-blue lake to bright green--a change that was readily apparent in satellite imagery," explained Hamilton. "Remarkably, 12 months after the spill the suspended sediment loads had substantially reduced, and the lake waters had appeared to return to their pre-spill state, but it turns out this was only temporary."

"Over the subsequent three years, we saw an increase in turbidity above the spill deposits at the bottom of the West Basin every spring and fall when winds drove large basin-scale wave motions, like the sloshing of water in your bathtub. As turnover occurred, this sediment was then mixed from depths below 100 metres over the whole water column."

Understanding effects

The biggest concern is the unknown effects of this phenomenon on the ecology of the lake. The tailings contained elevated concentrations of some metals, such as copper, and if these metals are being seasonally remobilized from the lake bed they could make their way into the food web. Chronic exposure to elevated copper concentrations can reduce the growth, reproduction, and survival of fish populations, and small changes to colour and clarity of a lake can alter algal communities at the base of the food web.

"In other related research, we have seen a seasonal increase in some metal concentrations in the Quesnel River that corresponds to the timing of the turbidity increase observed in the lake," explained Ellen Petticrew, professor at UNBC and co-author on the study. "This paper will help us explain some of these other processes we are observing, and helps build a more complete understanding of the long-term impact of the spill on the lake."

"While the immediate environmental devastation of other catastrophic mine waste spills around the world may have been more apparent, our research shows that the environmental impacts of the spill in Quesnel Lake are long-term," said Bernard Laval, professor of civil engineering at UBC. "Investigating these subtle impacts over time will help inform if and how Quesnel Lake recovers, and the potential for lasting impacts of other tailings spills which are increasingly frequent globally."

"Understanding all factors affecting the long-term water quality of Quesnel Lake is critical as its watershed supports substantial recreation, world-renowned resident trout fisheries, and multiple Fraser River Pacific salmon stocks that are vital to Indigenous, recreational, and commercial fisheries," added Hamilton. "Inevitably these spills end up flowing downstream into lakes or the ocean where they can disappear from view, yet that doesn't mean the impact is over."

What do lynx, flying squirrels, ravens, and wolverines have in common?

They will all scavenge from snowshoe hare carcasses under the right conditions, according to a new study by University of Alberta ecologists. And they're not alone. In fact, researchers documented 24 different species feeding from snowshoe hare carcasses in Canada's northern boreal forest.

"This is one of the most diverse scavenger communities recorded," said lead author Michael Peers, who conducted this research during his PhD studies under the supervision of ProfessorStan Boutin in the Department of Biological Sciences.

"Species we may think of as scavengers like common ravens, magpies, and wolverines were recorded, but also species that people might not expect to be scavengers. We documented snowshoe hares, Canada lynx, red squirrels, Northern flying squirrels, arctic ground squirrels, and chipmunks all scavenging."

The researchers examined the northern boreal forest in the Yukon over a four-year period from 2015 to 2018. Using remote sensing cameras, the researchers examined which animals scavenged from nearly 100 opportunistically placed snowshoe hare carcasses throughout the region.

The results indicate that prey species may have a more complex impact on food webs than previously thought, because their numbers influence both their direct predators as well as other animals who commonly scavenge.

"Scavenging by animals can have important impacts on food webs, but is often overlooked in food web research," explained Peers. "Our data shows that a lot of species scavenge in the boreal forest of Canada, and that changing temperatures or the abundance of keystone species can impact scavenging communities."

Antibiotic resistance is an increasing health problem, but new research suggests it is not only caused by the overuse of antibiotics. It's also caused by pollution.

Using a process known as genomic analysis, University of Georgia scientists found a strong correlation between antibiotic resistance and heavy metal contamination in an environment.

Jesse C. Thomas IV, an alumnus of the College of Public Health and the Savannah River Ecology Laboratory, found commonalities in soils contaminated with heavy metals on the U.S. Department of Energy's Savannah River Site near Aiken, South Carolina.

According to the study, published in the July issue of the journal Microbial Biotechnology, soils with heavy metals had a higher level of specific bacterial hosts that were accompanied by antibiotic-resistant genes.

Hosts included Acidobacteriaoceae, Bradyrhizobium and Streptomyces. The bacteria had antibiotic-resistant genes, known as ARGs, for vancomycin, bacitracin and polymyxin. All three drugs are used to treat infections in humans.

The bacteria also had an ARG for multidrug resistance, a strong defense gene that can resist heavy metals as well as antibiotics, according to Thomas, who was conducting his doctoral research at the time.

When these ARGs were present in the soil, metal-resistant genes, or MRGs, were present for several metals including arsenic, copper, cadmium and zinc.

Thomas, currently a biologist at the Centers for Disease Control and Prevention, said microorganisms develop new strategies and countermeasures over time to protect themselves.

"The overuse of antibiotics in the environment adds additional selection pressure on microorganisms that accelerates their ability to resist multiple classes of antibiotics. But antibiotics aren't the only source of selection pressure," Thomas said. "Many bacteria possess genes that simultaneously work on multiple compounds that would be toxic to the cell, and this includes metals."

Travis Glenn, professor in the public health college, advised Thomas during the study. He said more research needs to be done to determine if metal-resistant genes respond in the same way to bacteria as antibiotic-resistant genes.

Unlike antibiotics, heavy metals don't degrade in the environment so "they can exert long-standing pressure," according to Glenn, who also directs the Institute of Bioinformatics.

The study reports previous research identified antibiotic-resistance in heavy metal-contaminated streams on the site by examining water samples in the lab.

"When you expose the sample to a drug on a petri dish or assay, it only represents a fraction. This doesn't give you a complete picture. With genomic analysis we were able to get much further," Thomas said.

The significance of the research is they can start to characterize bacterial communities and specific ARG and MRG genes in the environment, Glenn said.

It is clear that there are several human pathogens that develop antibiotic resistance -- overuse is not the only cause, according to Thomas. Human activities like agriculture and the combustion of fossil fuels play a role.

"We need a better understanding of how bacteria are evolving over time," he said. "This can impact our drinking water and our food and eventually our health."

A major Houston health care system saw a significant increase in younger and Hispanic COVID-19 patients from the first surge to the second surge after Texas phased in reopening. Houston Methodist is the first to share such demographics in a peer-reviewed journal, publishing this analysis in a Journal of the American Medical Association (JAMA) Letter (online Aug. 13). The study shows that Houston Methodist reported a marked increase in Hispanic and younger COVID-19 patients between the first and second surges. Across the hospital system's eight locations, the number of Hispanic patients admitted for COVID-19 increased from nearly 26% to more than 43%. The data for Surge 2 (May 16-July 7) also revealed a demographic shift of the pandemic toward a younger and lower socio-economic patient population. The findings in the Houston Methodist research may help other health care organizations better prepare for surges and be a guide for managing hospital resources.