Earth

CORVALLIS, Ore. - Animals that evolved in environments subject to large-scale habitat-altering events like fires and storms are better equipped to handle forest fragmentation caused by human development than species in low-disturbance environments, new research shows.

Oregon State University scientists led an international collaboration whose work provides an important road map as conservation managers consider the effects of forest edges on wildlife in setting up reserves.

Findings of the study were published today in Science.

"Everyone knows habitat loss is bad for animals, but there's been a longstanding debate about fragmentation - the arrangement of remaining habitat," said co-corresponding author Matt Betts, a professor in the OSU College of Forestry and the director of the Forest Biodiversity Research Network. "How do we design wildlife reserves? Do we make many small ones, or fewer big ones, or do we make corridors?"

The study led by Betts and postdoctoral scholar Christopher Wolf suggests the closer a forest is to the equator, the more sensitive on average its wildlife species are to fragmentation. Tropical species have historically encountered much less disturbance than those in the temperate zones.

"Biodiversity of vertebrates increases massively toward the equator, but even accounting for that, a greater proportion of species are more sensitive to fragmentation," Betts said. "Sensitivity increases six-fold at low versus high latitudes. That means that not only should we care about the tropics because so many species are found there that are found nowhere else on Earth, but those species are also more sensitive to how we treat the forests."

Wolf cautions that the greater forest edge sensitivity at the lower latitudes, which are closer to the equator, does not mean there isn't also edge sensitivity in temperate zones.

"It's a matter of degree," he said. "We still found that almost one-fifth of species in temperate zones are edge avoiders. In comparison to the tropics, yes, more species are robust when it comes to dealing with fragmentation, but what that really means is that in the temperate zones, the focus should be on conserving habitat itself perhaps with less regard for the configuration patterns."

To test the "extinction filter hypothesis" - which predicts that forest species that have evolved in high-disturbance environments should be more likely to persist in the face of new disturbances - Wolf and Betts used 73 datasets of species abundances from around the globe. These datasets were collected by hundreds of field biologists over roughly the past decade.

The datasets contained 4,489 species from four major taxa - arthropods (2,682); birds (1,260); reptiles and amphibians (282); and mammals (265) - and the researchers used modeling software to separate the effects of fragmentation from other factors.

Wolf and Betts found that in low-disturbance regions, 51.3% of forest species tend to avoid forest edges compared to 18.1% in high-disturbance zones.

"Our work addresses why fragmentation studies worldwide can yield different results from one another," Wolf said.

Betts added that fragmentation will likely matter more in temperate zones in the years to come as species gradually move toward the poles in response to climate change.

"The novelty of this research is quantifying the degree to which geographic patterns in species sensitivity are predictable at the global scale," said Betsy von Holle, program director at the NSF, which funded the research. "Understanding the ecological underpinnings of these patterns has major implications for conservation."

Already, 70% of the Earth's remaining forest is within 1 kilometer of a forest edge, and fragmentation of the world's most intact forest landscapes - the ones in the tropics - is predicted to accelerate over the next 50 years, the researchers said.

"It's one thing to blow a whistle and another to figure out a way to deal with a problem," Betts said. "If we want to conserve the biodiversity needed for ecosystem services, and for its own sake, we must be particularly careful to minimize the creation of edges in the tropics, since fragmentation has a greater negative impact there."

A new technique reported in Science this week overcomes several limitations of typical high-throughput chemical screens conducted on cell samples. Such screens are commonly used to try to discover new cancer drugs, and in many other biomedical applications.

Most current screens of this nature offer either a coarse readout, such as of cell survival, proliferation or alterations in cell shapes, or only a specific molecular finding, such as testing whether a particular enzyme is blocked.

Because of the huge gap between those extremes, most assays routinely miss subtle gene expression or cell state changes that might unveil mechanisms triggered inside perturbed cells. Such assays can also fail to detect nuances that might indicate unexpected side effects of drugs being tested, or varying reactions among genetically identical cells to the same drug, or why cells become resistant to treatment that was previously working well.

To address these limitations, a research team representing many fields collaborated to develop a more informative technique.

"This technology actually occupies a niche between the two common kinds of assays," said one of the lead researchers, Sanjay R. Srivatsan, an M.D./Ph.D. student in the Medical Scientist Training Program at the University of Washington School of Medicine in Seattle. "You can get a sort of global view of the cellular responses. We think it's going to be really powerful to categorize drugs, for example, and say what their mechanism is."

The new technology combines improvements in labeling cell nuclei with advances in profiling which genes are expressed in each of millions of cells. This was accomplished at a single-cell resolution and in a cost-effective manner. They named the new screening method sci-Plex.

In the Dec. 5 online edition of Science, the researchers report their proof-of-concept findings. The lead authors of the paper, in addition to Srivatsan, are Jose L. McFaline-Figueroa, a postdoctoral fellow in genome sciences at the UW medical school; and Vijay Ramani, a former UW genome sciences graduate student who is now a Sandler Faculty Fellow at the University of California.

The senior researchers were Cole Trapnell, UW School of Medicine associate professor of genome sciences and an investigator at the Brotman Baty Institute for Precision Medicine in Seattle, and Jay Shendure, a UW medical school professor of genome sciences and scientific director of the Brotman Baty Institute. Shendure is also a Howard Hughes Medical Institute investigator and directs the Allen Institute Discovery Center for Cell Lineage Tracing.

"The sci-Plex technique allows us to pool lots of genetically different cells and see what happens to many individual cells as they are perturbed in many different ways," said Trapnell. "We then collect all the data together and analyze it using modern tools from machine learning and data science to understand something about what each of those drugs does to the cells."

To put sci-Plex through its paces, the researchers applied it to a screen using three kinds of cancer cell lines (leukemia, lung cancer and breast cancer) treated with 180 compounds used for cancer, HIV and autoimmune disease therapies. The cells were labeled with a nuclear hashing of small, single strands of DNA.

This hashing identifies different cells and permits scientists to map which cells received which drug. In just one experiment, the researchers measured gene expression in 650,000 single cells from more than 5,000 independently treated samples.

The results indicated significant differences in the ways some of the cancer cells reacted to specific compounds. They also revealed shared patterns among cells with regard to other chemical families as well as some properties that distinguished drugs within a chemical family.

The researchers delved more deeply into the mode of action of one class of cancer drugs, HDAC inhibitors. They saw that the gene regulatory changes matched the proposition that these inhibitors stopped cancer cell proliferation by blocking access to an energy source.

Describing another aspect of the research, Srivistan said, "It was really cool that we could use gene expression profiles to categorize the potency of drugs. With changes in dose over four orders of magnitude, we could see a smooth increase in the cellular response."

Overall, the sci-Plex results suggest that it could be scaled to thousands of samples to target diverse biochemical pathways, catalysts, regulators and modes of action.

"Some of this work could pertain to the treatment of disease, in helping medical researchers understand how certain drugs produce their effects, how the cell stage influences effectiveness, and why some medications work on some cells, but not on others," Trapnell said.

"Physicians also give many people the same handful of drugs, and they work for some people and not for others," Trapnell added. "Potentially sci-Plex could help us better understand why that is."

Trapnell said he believes sci-Plex could be a useful tool for precision medicine: "Ultimately when someone gets sick with cancer, we want to kill the whole tumor, all of the cells, not just some of the cells. So understanding why some individual cells respond one way to a drug and others respond differently is critical to designing therapies that will be completely effective."

A distinct advantage of sci-Plex, the researchers noted, is that it can distinguish how a compound affects subsets of cells. In addition to those that make up tumors, such subsets could also include lab-dish living models such as reprogrammed cells, organoids, and synthetic embryos.

The researchers predict that the ease and low cost of nuclear hashing, combined with the flexibility and scalability of their methods for single-cell sequencing, could give sci-Plex many basic research and practical applications in biomedicine. For example, it might help in building a comprehensive atlas of cellular responses to pharmaceutical interventions.

"It's a very generalizable strategy," Srivatsan said. "It can be performed with reagents which any scientist can acquire and it can be used in many ways."

Trapnell agreed. "I'm really interested in how the single-cell genomics scientific community picks this up for things we didn't anticipate. That happens all the time in our field. Technology developers and experimental biologists are repurposing techniques in all kinds of ways that the original developers did not envision."

Three of the scientists on this project, none of them named in this news release, declared financial interest in the form of stock ownership and employment in Illumina, Inc. One or more patents filed by Illumina or the UW may encompass the methods or data reported in the Science paper.

Placing lights on fishing nets reduces the chances of sea turtles and dolphins being caught by accident, new research shows.

LED lights along the top of floating gillnets cut accidental "bycatch" of sea turtles by more than 70%, and that of small cetaceans (including dolphins and porpoises) by more than 66%.

The study, by the University of Exeter and Peruvian conservation organisation ProDelphinus, looked at small-scale vessels departing from three Peruvian ports between 2015 and 2018, and found the lights didn't reduce the amount of fish caught from "target species" (ie what the fishers wanted to catch).

The findings support previous research which suggested LED lights reduce bycatch of seabirds in gillnets by about 85%.
Gillnets, which can be either anchored or move with the ocean currents, are designed to entangle or snare fish by the gills, and are the largest component of small-scale fisheries in many countries.

"Gillnet fisheries often have high bycatch rates of threatened marine species such as sea turtles, whales, dolphins and seabirds," said lead author Alessandra Bielli, who carried out analyses as part of her masters research at the Centre for Ecology and Conservation at Exeter's Penryn Campus in Cornwall.

"This could lead to declines in the populations of these non-target species - yet few solutions to reduce gillnet bycatch have been developed.

"Sensory cues - in this case LED lights - are one way we might alert such species to the presence of fishing gear in the water."

The researchers placed lights every 10m along the float line of 864 gillnets, pairing each with an unlit net to compare the results.

"The dramatic reduction in bycatch of sea turtles and cetaceans in illuminated nets shows how this simple, relatively low-cost technique could help these species and allow fishers to fish more sustainably. Given the success we have had, we hope other fisheries with bycatch problems will also try illuminating their fishing nets," said Exeter PhD graduate Dr Jeffrey Mangel, of Peruvian NGO ProDelphinus.

Most of the turtles caught in the study were green turtles (86%), though loggerhead and olive ridley turtles were also caught.

Among the small cetaceans captured, 47% were long-beaked common dolphins, 26% were dusky dolphins and 24% were Burmeister's porpoises.

"This work has further shown the usefulness of lights on nets to save wildlife. We now need lights that are ever more robust and affordable," said Professor Brendan Godley, of the University of Exeter.

A joint research team led by MAO Fangyuan from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences and MENG Jin from the American Museum of Natural History reported a new symmetrodont, Origolestes lii, a stem therian mammal from the Early Cretaceous Jehol Biota, in China's Liaoning Province.

A key feature of Origolestes is that the bone link between the auditory bones and Meckel's cartilage has disappeared, showing the separation of the hearing and chewing modules in therian mammalian evolution. Their findings were published in Science on Dec. 5.

The new species was established based on multiple 3D skeletal specimens. The researchers reconstructed 3D skeletal morphologies of the animal using high-resolution microtomography (micro CT). The buried forms of the specimens show that these animals died at rest. As a result, the skeletons were basically undisturbed during fossilization, thus allowing the detailed structures to be preserved.

Skull morphologies, dentitions, jaws, and tooth wear from individuals of the same species show evidence of opening and closing movements during the biting and chewing process as well as jaw yawing and rolling.

"The multidirectional movements of the mandibular during chewing are likely to be one of the selection pressures that caused the detachment of the auditory ossicles from the dental bone and the Meckel's cartilage," said MAO.

This decoupled feature in Origolestes bridges the morphological gap between the transitional and the definitive mammalian middle ear and represents a more advanced stage in the evolution of the mammalian middle ear.

From the perspective of morphology and function, the decoupled hearing and chewing modules eliminated physical constraints that interfered with each other and possibly increased the capacity of the two modules to evolve.

Therefore, the hearing module may have had greater potential to develop sensitive hearing of high frequency sounds, and the chewing module may have been able to evolve diverse tooth morphologies and occlusal patterns that facilitated consuming different foods.

Thanks to the high-resolution micro-CT scan, the researchers were able to image the 3D ossicular morphologies of Origolestese. These morphologies are probably the most complete among known Mesozoic mammals and provide rich and unequivocal fossil evidence for future study of the mammalian middle ear evolution.

A special feature of Origolestes is that its middle ear also retained the surangular bone, in addition to the stapes, malleus, incus, and ectotympanic, which all mammals have. It is notably absent in other mammals.

This feature poses a challenging problem for the study of paleomammals and modern developmental biology: Was this ossicular bone completely lost during mammalian evolution or does it persist in extant mammals in a way that people don't notice? More discoveries of relevant fossils and more detailed studies of developmental biology may eventually answer this question.

According to a much-debated geo-engineering approach, both sea-ice retreat and global warming could be slowed by using millions of wind-powered pumps, drifting in the sea ice, to promote ice formation during the Arctic winter. AWI researchers have now, for the first time, tested the concept using a complex climate model and published their findings in the journal Earth's Future. Their verdict is sobering: though the approach could potentially put off ice-free Arctic summers for a few more decades, beyond the Arctic the massive campaign wouldn't produce any meaningful cooling effect.

Though it sounds like science fiction, it's a serious suggestion to combat climate change: ten million wind-powered pumps, distributed throughout the Arctic, are intended to promote the formation of sea ice in the winter. They would continually pump seawater onto the surface of the ice, where it would freeze. The now-thicker ice could then survive the summertime melting longer and therefore reflect sunlight longer where otherwise the darker ocean would readily take up the sun's warming rays. This could not only slow the loss of Arctic sea ice, but also mitigate remote impacts, perhaps even the warming in lower latitudes. The idea, first proposed by US researchers as 'Arctic ice management' in the journal Earth's Future in 2017, was recently put to the test in a coupled climate model by two experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). What they found: from a purely physical standpoint, the near-total loss of summertime sea ice, which will likely come by mid-century in the 'business-as-usual' scenario, could indeed be pushed back to the end of the century. However, this grace period would not entail any significant cooling for the climate in Europe or around the globe.

"We wanted to know whether this manipulation of the Arctic sea ice could work in purely physical terms, and what effects it would have on the climate," says Lorenzo Zampieri, an environmental physicist and doctoral candidate from the AWI's sea-ice prediction research group. Accordingly, he modified the AWI climate model so that the physical effect produced - the constant pumping of water onto the sea ice's surface throughout the winter - could be simulated. As Helge Goessling, head of the research group, explains: "Normally the growth of the ice is limited by the fact that, as it becomes thicker, the ice increasingly insulates the ocean from the winter cold; for this reason, typically you won't find an overall thickness of more than a few metres. But the pumps do away with this limiting effect, because new layers are added to the ice from above." Initial simulations based on pumps churning seawater onto the ice throughout the Arctic show: year after year, the ice would gain between one and two metres in thickness. According to the climate model, the global warming produced by CO2 wouldn't put an end to this growth until the end of the century. And what about the effects on the climate? The summertime warming of the Arctic would in fact be lessened by several degrees Celsius, as projected in the original publication. However, pumping the comparatively warm (-1.8 °C) water would also alter the thermal flow in winter, resulting in a substantial warming of the Arctic in winter. This thermal energy would also be transported to the middle latitudes and stored in the ocean there.

In the next step, the researchers conducted more realistic simulations in which the pumps were only deployed where the ice was less than two metres thick. "Two-metre-thick ice already has the best chances of surviving the summertime melting, and by limiting the distribution of pumps in this way, the unnecessary and considerable wintertime warming can also be avoided," says Lorenzo Zampieri. In this scenario, the undesirable additional warming of the middle latitudes could in fact be avoided, but the scheme would still do little to mitigate climate change. Though the warming of the Arctic in summer would be reduced by roughly one degree Celsius, and the loss of the sea ice could be delayed by roughly 60 years, the increased reflection of sunlight wouldn't be sufficient to slow climate change outside the Arctic.

"Given the unchecked progression of climate change to date, geo-engineering can't be dismissed as mere nonsense by the climate research community," claims Helge Goessling. Instead, these ideas need to be subjected to scientific scrutiny. Arctic 'ice management', both authors agree, is interesting in its own right, but can't meaningfully mitigate global climate change; as such, it should remain science fiction.

TALLAHASSEE, Fla. -- A team of Florida State University researchers studying new methods to remove toxic heavy metals from biosolids -- the solid waste left over after sewage treatment -- found the key is a brief spin through a microwave.

The method removed three times the amount of lead from biosolids compared to conventional means and could reduce the total cost of processing by more than 60 percent, making it a possible engineering solution to help produce fertilizer and allow more people to live with clean soil and water. The research is published in the Journal of Cleaner Production.

"Biosolids are a valuable resource, but heavy metals prevent their use," said Gang Chen, a professor of Civil & Environmental Engineering at the FAMU-FSU College of Engineering.

As the human population of the planet grows and more people move to cities, sewage treatment plants around the world are producing more biosolids. Those byproducts are often disposed of in landfills or incinerators, but there are drawbacks to those solutions, such as high costs or secondary pollution from the treatment process itself.

Another option is to compost the biosolids, using them as an ingredient in fertilizer that finds a second life in agriculture. In the United States, about half of all biosolids are recycled.

Before disposal or recycling can happen, they need to be made safe to use. One obstacle is the presence of heavy metals, so named for their high atomic weight. Because these potential toxins can leach into the environment from biosolids, it's important to extract them. However, that extraction can be expensive.

Chen and his team turned to their knowledge of energy to develop a more efficient process.

The investigation started from theory. They calculated the amount of energy that was needed to break the bonds that attached the heavy metals to the rest of the biosolid but would not destroy the biosolid itself. Somewhere on the electromagnetic spectrum, Chen's group found the radiation with the right amount of energy.

Microwave radiation seemed to be just right. After treatment in a microwave, researchers were able to remove the heavy metals from biosolids with a lower dosage of treatment chemicals than traditional extraction requires.

It's a technique that can be scaled up to facilities that service a city or a region to give them a less expensive way to make biosolids safe, Chen said.

It's important work, because if heavy metals remain in biosolids that are applied to soil, those metals can be absorbed by plants, which become part of the food chain for animals or humans. As they accumulate in the body, they can cause intellectual disability in children, dementia in adults, central nervous system disorders and damage to organs.

"We want to break the loop," Chen said.

Former doctoral student Simeng Li, a current assistant professor in the Department of Civil Engineering at California State Polytechnic University, Pomona, Runwei Li, a doctoral candidate in the FAMU-FSU College of Engineering, and Youneng Tang, an assistant professor of Civil & Environmental Engineering in the FAMU-FSU College of Engineering, contributed to this study. This research was supported by the Hinkley Center for Solid and Hazardous Waste Management.

The interaction between light and matter is the basis of both many fundamental phenomena and various practical technologies. Most famously, in the photoelectric effect, electrons are emitted from a material that is exposed to light of suitable energy. For long, the origin of the phenomenon remained a riddle, and only with the advent of quantum theory -- and thanks to the genius of Albert Einstein -- was the effect fully understood. Einstein received the 1921 Nobel Prize in Physics for his discovery of the underlying laws, and since then the effect has been harnessed in applications ranging from spectroscopy to night-vision devices. In some important cases, the key principle is the transfer not of energy but of linear momentum -- or, impulse -- from photons to electrons. This is the case, for instance, when laser light is used to cool microscopic and macroscopic objects, or to understand the phenomenon of radiation pressure.

Despite the fundamental importance of momentum transfer, the precise details of how light passes its impulse on to matter are still not fully understood. One reason is that the transferred impulse changes during an optical cycle on extremely fast, sub-femtosecond timescales. So far, studies revealed mainly information on time-averaged behaviour, missing time-dependent aspects of the linear-momentum transfer during photoionisation. This gap has now been filled by the group of Ursula Keller at the Institute for Quantum Electronics, as they report in a paper published today in Nature Communications.

They looked at the case of high laser intensities, where multiple photons are involved in the ionisation process, and investigated how much momentum is transferred in the direction of laser propagation. To achieve sufficient time resolution, they employed the so-called attoclock technique, which has been developed and refined in the Keller lab over the past decade. In this method, attosecond time resolution is achieved without having to produce attosecond laser pulses. Instead, information about the rotating laser-field vector in close to circular polarised light is used to measure time relative to the ionisation event with attosecond precision. Very similar to the hand of a clock -- just now this clock hand is rotating through a full circle within one optical cycle of 11.3-fs duration.

With this versatile tool at hand, the ETH physicists were able to determine how much linear momentum electrons gained depending on when the photoelectrons were 'born'. They found that the amount of momentum transferred in the propagation direction of the laser does indeed depend on when during the oscillation cycle of the laser the electron is 'freed' from the matter, in their case xenon atoms. This means that at least for the scenario they explored, the time-averaged radiation pressure picture is not applicable. Intriguingly, they can reproduce the observed behaviour almost fully within a classical model, whereas many scenarios of light-matter interaction, such as Compton scattering, can only be explained within a quantum mechanical model.

The classical model had to be extended though, to take into account the interaction between the outgoing photoelectron and the residual xenon ion. This interaction, they show in their experiments, induces an additional attosecond delay in the timing of the linear momentum transfer compared to the theoretical prediction for a free electron born during the pulse. Whether such delays are a general property of photoionisation or if they apply only for the sort of scenarios investigated in the present study remains open for now. What is clear, however, is that with this first study of linear momentum transfer during ionisation on the natural timescale of the process, the Keller group opened up a new exciting route to explore the very fundamental nature of light-matter interactions -- thus making good on a central promise of attosecond science.

From early story concepts to a theatrical release, full-length animated films can take years to create. One of the biggest time commitments comes during the animation process when the animators are simulating fluid materials, like water or hair.

Think about the Disney character Elsa in the film "Frozen 2" as she is running across the ocean and turning water into ice.

That simulation process can take more than a day to compute for one scene and is very costly. For filmmakers, it's also hard to nail down a perfect scene on the first try.

"If the animator invests the time to run a simulation then the director looks at it and says it's not quite right, he or she has to start from scratch, change some parameters and run the entire simulation again," said BYU professor Parris Egbert. "That process will be repeated as many times as it takes for the director to approve it."

To help solve that time and money issue, a team of computer science professors at BYU created a method to quickly resize animations of fluids without having to completely re-simulate the entire sequence.

This is achieved through a process called "fluid carving." An example of this occurring on a static dimensional image is when one changes the size of the image without losing relevant information or distorting the picture. This is done by taking out pixels that are deemed by a mathematical function to be unnecessary to the overall image.

Now, with their new method, the team at BYU can edit a 4-dimensional video, which is a 3-dimensional image spread out over time, in the same way.

"With our method, the animator can simply make it smaller and move on," Egbert said of their research which they recently presented at the ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Australia.

Making it smaller allows the animator to tweak and change the animation on the fly instead of waiting for an extended period of time for the simulation to be complete.

The function is a very complex piece of math and took the group almost a year to finalize.

"Probably the most difficult thing was figuring out how you carve these seams through a 4-dimensional volume. Not to mention the task of keeping it all straight as you're going along," Egbert said.

BYU computer science professors Seth Holladay and Bryan Morse, along with graduate student Sean Flynn, rounded out the team.

NASA-NOAA's Suomi NPP satellite passed over the Arabian Sea and captured a visible image of Tropical Storm 06A, now renamed Tropical Storm Pawan.

Visible imagery from NASA satellites help forecasters understand if a storm is organizing or weakening. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of 06A on Dec. 5.  VIIRS showed Tropical Storm Pawan or 06A was moving through the western Arabian Sea, spreading clouds as far northwest as Oman and Yemen on its way toward Somalia. Satellite imagery has shown limited deep convection and development of strong thunderstorms over the partially exposed low-level circulation center.

On Dec. 5, at 4 a.m. EST (0900 UTC), Tropical Cyclone Pawan (06A) was located near latitude 9.5 degrees north and longitude 55.9 degrees east, about 462 miles south-southeast of Salalah, Oman. The storm was moving to the west and had maximum sustained winds 40 knots (45 mph/74 kph). The storm is expected to weaken over the next day as it approaches Somalia.

Tropical Cyclone Pawan (06A) is in the process of turning west-southwest and is expected to make landfall in Somalia by Dec. 7.

Tropical cyclones and hurricanes are the most powerful weather events on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

NASA's Aqua satellite captured an image of Tropical cyclone 02S and the visible image showed that the storm was getting better organized.

Tropical Cyclone 02A formed as a tropical depression in the Southern Indian Ocean on Dec. 4 and strengthened into a tropical storm.

On Dec. 5, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite provided a visible image of 02S. The MODIS image showed powerful thunderstorms circling the center of circulation and a large, thick band of thunderstorms feeding into the center from the west.

The shape of the storm is a clue to forecasters that a storm is either strengthening or weakening. If a storm takes on a more rounded shape it is getting more organized and strengthening. Conversely, if it becomes less rounded or elongated, it is a sign the storm is weakening. 02S appeared more circular than it did 24 hours before, indicating it was strengthening and consolidating.

On Dec. 5 at 4 a.m. EST (0900 UTC), Tropical Cyclone 02S was located near latitude 6.7 degrees south and longitude 50.9 degrees east, about 867 miles north-northwest of St Denis, La Reunion Island. 02S is moving west-southwest and has maximum sustained winds 40 knots (46 mph/74 kph).

Tropical Cyclone 02S is forecast to turn to the south-southwest. The storm is forecast to make landfall in northwestern Madagascar after five days.

NASA's Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones and hurricanes are the most powerful weather events on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

Extensive evidence from HIV prevention research studies has firmly established that "Undetectable Equals Untransmittable," or U=U. This means that people living with HIV who achieve and maintain an undetectable viral load--the amount of virus in their blood--by taking antiretroviral therapy (ART) as prescribed do not sexually transmit HIV to others. The U.S. Centers for Disease Control and Prevention estimates this strategy is 100% effective against the sexual transmission of HIV.

Now, a new study of nearly 112,000 men who have sex with men in the United States has found increasing acceptance of the U=U message in this population. Overall, 54% of HIV-negative participants and 84% of participants with HIV correctly identified U=U as accurate. The study was supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Study results were published online today in the Journal of Acquired Immune Deficiency Syndromes.

"U=U has been validated repeatedly by numerous studies as a safe and effective means of preventing the sexual transmission of HIV," said Anthony S. Fauci, M.D., NIAID Director. "The increased understanding and acceptance of U=U is encouraging because HIV treatment as prevention is a foundation of efforts to end the epidemic in the United States and around the world. This public health message has the power to reduce stigma, protect the health of people living with HIV and prevent sexual transmission of HIV to others."

Researchers led by H. Jonathon Rendina, Ph.D., M.P.H., at Hunter College of the City University of New York, collected data from secure online surveys promoted on social media and mobile dating apps from November 2017 through September 2018. By analyzing the responses of self-identified sexual minority men, researchers found that approximately 55% of participants responded "completely accurate" or "somewhat accurate" to the question: "With regard to HIV-positive individuals transmitting HIV through sexual contact, how accurate do you believe the slogan Undetectable = Untransmittable is?"

Acceptance of U=U was far stronger among participants who self-reported to be living with HIV (84%) compared to HIV-negative participants (54%) and those who did not know their HIV status (39%). Researchers found U=U acceptance had increased over time by comparing the data to findings from a similar study by the same group that analyzed data collected in 2016 and early 2017. Among the 12,200 sexual minority men surveyed at that time, only 30% of HIV-negative participants and 64% of participants living with HIV agreed that U=U was completely or somewhat accurate.

In the current study, HIV-negative participants who reported seeking HIV testing and prevention services, as well as those taking daily pre-exposure prophylaxis (PrEP), were more likely to believe U=U was accurate. These findings suggest that U=U acceptance correlates to more frequent interactions with HIV prevention services. Among respondents with HIV, those who reported excellent adherence to ART were more likely to agree that U=U is accurate compared to those who reported "less than excellent" adherence or not being on ART at all.

The online survey also asked respondents to use a graduated scale from 0% ("no risk") to 100% ("complete risk") to rate the risk of an man whose HIV was undetectable transmitting the virus to his HIV-negative partner through either insertive or receptive anal sex without a condom. While studies confirm that a person whose HIV is suppressed do not transmit the virus through sexual activity, only 10% of all respondents rated the transmission risk as zero when the insertive partner has undetectable virus. Similarly, only 14% of respondents rated transmission risk as zero when HIV in the receptive partner is undetectable.

Among those who agreed that U=U was "completely accurate," only 31% and 39% believed transmission risk is zero when the insertive or receptive partner, respectively, has undetectable virus. However, acceptance of U=U was associated with lower perceived risk of HIV transmission through any form of condom-less anal sex.

"A growing number of sexual minority men believe that U=U is accurate, but our data suggest that most still overestimate the risk of HIV transmission from an undetectable partner, which may be because people have trouble understanding the concept of risk," said Dr. Rendina, the lead author on the study. "All published studies point to undetectable viral load as being the most effective method to date of preventing sexual HIV transmission, but most of our messaging has focused on the level of risk being zero rather than describing it in terms of effectiveness, which is the way we usually talk about condoms and PrEP."

All data collected in the online survey was confidential and self-reported. Study participants represented all U.S. states and were of various races and ethnicities, including 14% Black and 24% Latino. Participants ranged in age from 13 to 88 years old with a median age of 32. About 79% identified as gay, 18% as bisexual, and 3% as queer. Approximately 1% of respondents identified as transgender.

Earlier this year, Dr. Fauci and his colleagues wrote about the strength of scientific validation for the HIV treatment as prevention strategy and U=U in a JAMA commentary. The efficacy of treatment as prevention was first verified on a large scale by the NIH-funded HPTN 052 clinical trial, which showed that no linked HIV transmissions occurred among serodifferent heterosexual couples when the partner living with HIV had a durably suppressed viral load. Subsequently, the PARTNER 1 and 2 and Opposites Attract studies confirmed these findings and extended them to male-male couples. As described by authors of the current study, the independent non-profit organization Prevention Access Campaign launched the U=U slogan in 2016 to promote awareness of these scientific findings.

Importantly, U=U refers only to the prevention of sexually transmitted HIV; condoms are still needed to prevent the transmission of other sexually transmitted infections.

Research from doctors at The Ohio State University Wexner Medical Center finds a new "virtual biopsy" allows them to definitively diagnose cysts in the pancreas with unprecedented accuracy. This means they can eliminate precancerous cysts and potentially save lives.

The current standard involves testing the fluid inside the cysts. It correctly identifies them as benign or precancerous 71% of the time. Researchers found that when the virtual biopsy is added to the standard of care, the diagnostic accuracy jumps to 97%. The study is published in Clinical Gastroenterology and Hepatology and was recently presented at the American Pancreatic Association's Annual Meeting.

"Pancreatic cysts are common, and it can be difficult to distinguish the benign cysts from those destined to become cancerous, but this procedure allows us to do that quickly and with confidence," said Dr. Somashekar Krishna, a gastroenterologist and lead author of the study. "We hope that, at the end of the day, we are saving lives either by diagnosing pancreatic cancer early on before it develops into cancer, or we are preventing unnecessary surgery of a benign, harmless pancreatic cyst."

The diagnostic method tested in the study provides doctors with a microscopic view of the cyst wall, which is produced by a tiny scope that emits laser light inside the cyst. This allows doctors to determine almost immediately if it is precancerous.

"Many times, we are able to tell the patient right after the procedure, 'You have a precancerous cyst, and we need to send you to the surgeon to have it removed'," said Krishna, who is an associate professor in Ohio State's College of Medicine and is also affiliated with The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC - James).

A majority of patients get diagnosed with pancreatic cysts incidentally when getting a MRI or CT scan for another reason. Nearly 40% of MRIs done of the abdomen reveal pancreatic cysts and the chance of having them increases with age.

More than 45,000 Americans die of pancreatic cancer each year, making it the third-leading cause of cancer deaths. Patients usually don't have symptoms until the cancer is advanced, making early diagnosis and treatment a challenge.

Ohio State researchers are now working to train doctors at hospitals nationwide to perform this new diagnostic method and read the images provided by the scope to catch dangerous cysts and prevent pancreatic cancer for more patients. They're also working to develop artificial intelligence that will flag cases that are likely precancerous so doctors can act quickly.

Rats exchange information about danger in a reciprocal fashion, and this information transfer is at least partially mediated by a brain region called the anterior cingulate cortex, according to a study published December 5 in the open-access journal PLOS Biology by Christian Keysers of the Netherlands Institute for Neuroscience and the University of Amsterdam, and colleagues.

The ability to anticipate threats and deploy defensive responses appropriately is key to survival. Rodents have evolved mechanisms to use the response of conspecifics to more selectively deploy defensive behavior in anticipation of danger. Until now, social transmission of freezing - a behavioral manifestation of fear in rodents -- was conceived of as a one-way phenomenon in which an observer perceives the fear of another. In the new study, Keysers and colleagues systematically quantified the transfer of information between rats in the context of danger, and how this information transfer is affected by deactivation of the anterior cingulate cortex -- a brain region that contains emotional mirror neurons in rodents. Unlike more traditional methods that focus on one direction of information flow at a time, the methods the researchers introduced allowed them to capture social influences in both directions in the same paradigm. The paradigm they developed in the lab involves a shock-experienced observer rat interacting through a perforated transparent divider with another rat receiving footshocks.

The results suggest that rats exchange information about danger in both directions; how the observer reacts to the other rat's distress also influences how the rat receiving footshocks responds to the danger. This is true to a similar extent across highly familiar and entirely unfamiliar rats, but is stronger in animals pre-exposed to shocks. The effect of pre-exposure suggests that information transfer about danger is not entirely inborn; instead, part of the information transfer depends on some form of learning, similar to cross-species transfer of danger information via eavesdropping. Moreover, deactivating the anterior cingulate of observers reduces freezing in the observers and in the rats receiving the shocks. Taken together, the findings suggest that coupling of freezing across rats could enhance the efficient detection of danger in a group, similar to cross-species eavesdropping.

"What we observed, was striking," said Christian Keysers. "Without the region that humans use to empathize, the rats were no longer sensitive to the distress of a fellow rat. Our sensitivity to the emotions of others is thus perhaps more similar to that of the rat than many may have thought."

They go on to say, "What our data suggest, is that an observer shares the emotions of others because it enables the observer to prepare for danger. It's not about helping the victim, but about avoiding to become a victim yourself."

Protocells -- artificial cells -- that are active and mimic living cells by moving independently and that are biocompatible and enzymatically active are now possible using an improved method developed by Penn State researchers.

Living cells are difficult to grow in the laboratory, so researchers sometimes work with synthetic cells, but these have had research limitations because they lack real cell characteristics.

"One of the challenges of cell research is it's sometimes very hard to run controlled experiments on a?cell's motility, especially due to surface enzyme activity," said Darrell Velegol, distinguished professor of chemical engineering. "The research team developed a simple way to make an artificial cell that doesn't do everything a regular cell does, like reproduce, have genetic mutations or anything like that, but it actively moves. That's important because how cells move is poorly understood, especially how enzymes' activity play into cell movement."

The team's protocells are used to investigate how the activity of natural enzymes like ATPase can propel the active movement of the protocells. The biochemical process of ATPase enzyme involves conversion of ATP (adenosine triphosphate) into the product ADP (adenosine diphosphate). ATP is a complex organic chemical that provides energy for living cells and ADP is an organic compound that plays an important role in how cells release and store energy.

"Attempts at similar experiments in the past decade had the enzymes incorporated inside of micron-sized sacks called polymeric vesicles, or tethered onto the surface of hard particles," said Subhadip Ghosh, postdoctoral researcher in chemistry. "But these attempts didn't have significant biological resemblance like our protocells."

In the research team's experiments, the protocells have actual artificial membranes composed of a naturally occurring lipid called phosphatidylcholine. The ATPase enzymes were incorporated directly into the membrane.

"Our results basically give other researchers the first steps toward making artificial cells with enzymatic activity," Ghosh said.

One unexpected result from the study, which was made available online in August 2019 ahead of final publication on September 11, 2019 in an issue of Nano Letters, happened during diffusion experiments which were performed at a single molecular regime. As expected, the movement of the protocells was low for low concentrations of ATP.

"Quite surprisingly, the movement of the protocells dropped significantly at high concentration of ATP," said Ayusman Sen, the Verne M. Willaman Professor of Chemistry at Penn State.

According to the researchers, this was as counterintuitive as pressing an automobile's gas pedal and having the vehicle slow down. After performing comprehensive control experiments, the researchers concluded that when ADP concentration is high, it may bind to the ATPase and suppress the substrate ATP activity, causing reduced motility.

Having the ability to fabricate the enzymatically active protocells opens new opportunities. Armed with these mimics of motile living cells, the researchers aim to reveal the fundamental mechanisms governing active membrane dynamics and cellular movement.?Given the current limited understanding of how cells move, including how enzyme action plays into cell movement, the research team members believe their work can have significant implications for future medical research.

"A key challenge is to estimate the mechanical forces that drive the protocell movement, and to discover changes in the enzyme structure during that process," said Farzad Mohajerani, research assistant in chemical engineering. "Knowing that structure-function relationship for the movement of the protocells will enable their design for potential in vivo applications like medical sensing and lab analysis."

NASA's Terra satellite captured an image of Tropical Cyclone Ambali and the visible image showed that the storm was rapidly intensifying.

Ambali formed as a tropical depression in the Southern Indian Ocean on Dec. 4 and quickly strengthened into a tropical storm. Today, Dec. 5, it has reached what is considered hurricane status in the Atlantic and Northeast Pacific.

On Dec. 5, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Terra satellite provided a visible image of Ambali. The MODIS image showed powerful thunderstorms circling the center of circulation. Meanwhile microwave satellite imagery shows tight banding of thunderstorms around the center of circulation and the development of an eye.

The shape of the storm is a clue to forecasters that a storm is either strengthening or weakening. If a storm takes on a more rounded shape it is getting more organized and strengthening. Conversely, if it becomes less rounded or elongated, it is a sign the storm is weakening. Ambali appeared more circular than it did 24 hours before, indicating it was strengthening and consolidating.

On Dec. 5 at 10 a.m. EST (1500 UTC), Tropical Cyclone Ambali was located near latitude 9.2 degrees south and longitude 62.7 degrees east, about 595 miles west-southwest of Diego Garcia. Ambali is moving west-southwest and has maximum sustained winds 70 knots (81 mph/130 kph).

Ambali will move south-southwest as it rapidly intensifes. Ambali is expected to peak at 100 knots (115 mph/185 kph) later today before running into hostile atmospheric conditions leading to dissipation in four days.