Tech

Patients taking warfarin to reduce the risk of stroke and pulmonary embolisms are often advised to take the medication in the evening. But does time of day really matter? A new study shows evidence that morning versus evening dosing has insignificant bearing on how long the drug provides the most benefit for preventing adverse health events. Two hundred and seventeen adults who regularly used warfarin in the evenings were randomized to the trial, with about half switching to morning medication use for seven months. Researchers measured the effectiveness of the drug by tracking the proportion of time that patients spent outside of the range for maximum effectiveness of the drug. Therapeutic changes did not significantly differ for patients who switched to morning administration. The clinical research team concluded that the time of day a patient takes the medicine has no effect on the stability of warfarin's anticoagulant effect. Patients should take warfarin whenever regular compliance would be easiest.

FEBRUARY 18, 2020, NEW YORK -- A Ludwig Cancer Research study has identified a mechanism by which regulatory T cells, which suppress immune responses, adapt their metabolism to thrive in the harsh microenvironment of the tumor. This mechanism, the study finds, is exclusively engaged by regulatory T cells (Tregs) that reside in tumors and could be disrupted to selectively target such Tregs and boost the effects of cancer immunotherapy.

"It has long been known that the Tregs found in tumors protect cancer cells from immune attack, so countering Tregs would be an important strategy for cancer immunotherapy," says Ping-Chih Ho, associate member of the Lausanne Branch of the Ludwig Institute for Cancer Research, who led the study. "But a major hurdle to such interventions is that the systemic suppression of Treg activity can cause severe autoimmune reactions. We have discovered a potential approach to overcoming that problem, one that selectively targets Tregs in tumors and could therefore prevent such adverse effects."

Tregs play a critical role in healthy tissues, where they prevent autoimmune disease and aid wound-healing. But, when recruited into tumors, Tregs also thwart anti-cancer immune responses--and immunotherapy. The current study, published in Nature Immunology, identifies a protein that drives the metabolic adaptations of intratumoral Tregs. The researchers show in a mouse model of melanoma that targeting that protein with an antibody significantly boosts the efficacy of immunotherapy without causing autoimmune side effects.

The cores of tumors are often acidic and starved of oxygen and vital nutrients, which forces resident cells to adapt their metabolism to survive. Ho and graduate student Haiping Wang suspected those adaptations might also reveal vulnerabilities unique to intratumoral Tregs. To find those vulnerabilities, they analyzed a dataset of Treg gene expression in breast tumors and blood compiled a few years ago by the laboratory of Ludwig MSK Director Alexander Rudensky.

They found that those and other intratumoral Tregs expressed high levels of genes involved in lipid uptake and metabolism--particularly CD36, a receptor involved in lipid import. An analysis of Tregs from human melanoma patients conducted by Ludwig Memorial Sloan Kettering (MSK) researchers Taha Merghoub and Jedd Wolchok yielded similar results.

To explore the role of CD36 in intratumoral Tregs, the researchers generated mice that lacked the CD36 gene only in their Treg cells and engrafted them with melanoma. "We found that the tumor burden was reduced in CD36-deficient mice," says Wang, "and the number and functionality of Tregs declined only within tumors, not in the other, healthy tissues of the mice."

CD36 deficiency induced in intratumoral Tregs a form of cell suicide known as apoptosis that was driven by a decline in the health and number of mitochondria--the power generators of cells. Further study revealed that CD36 fuels the activity of PPARβ, a protein essential to the genesis and function of mitochondria.

Treating mice bearing melanoma tumors with an antibody to CD36 resulted in a decline of intratumoral Tregs that was not seen in genetically identical control mice. When this antibody was combined with an immunotherapy known as PD-1 blockade, which stimulates a T cell attack on cancer cells, tumor growth slowed significantly, prolonging the survival of the mice.
"By targeting CD36 with an antibody, we don't just create trouble for intratumoral Tregs, we also create trouble for the tumor's ability to maintain an immunosuppressive microenvironment and hamper immunotherapy," says Ho.

Ho's lab is now working to translate these findings into a potential cancer therapy while exploring how CD36-targeting might be combined with other interventions to more extensively disable Tregs selectively within tumors. They are also exploring which other types of solid tumors harbor Tregs that are dependent on CD36 for survival.

Climate change is being felt in a corner of the world different from where one might expect: Wall Street, where some of the biggest investors are starting to take action.

That's the finding of a first-ever survey of institutional investors conducted in part by the McCombs School of Business at The University of Texas at Austin. From banks and insurers to pension and mutual funds, 97% of 439 respondents believe global temperatures are rising. More than half say climate risks are already a factor in their investment decisions, according to "The Importance of Climate Risks for Institutional Investors" published in the March 2020 issue of The Review of Financial Studies.

"These investors have accepted that climate change is happening," said Laura Starks, finance professor at Texas McCombs, who designed the survey with colleagues Philipp Krüger of the University of Geneva and Zacharias Sautner of the Frankfurt School of Finance & Management. "They're trying to come to terms with how it's going to affect the risk and return of their portfolios."

The survey also reveals how institutions are starting to act. Their tactics range from asking companies to catalog carbon emissions to backing shareholder resolutions. If institutions are not satisfied with executives' responses, a few are divesting their shares.

Such measures are only the beginning, the survey suggests. Within five years, fully 91% expect climate risks to be financially material to their investments.

Of executives who filled out the survey, 31% were C-level. Forty-eight percent of the 439 respondents managed more than $100 billion in assets. Institutions' responses paint a mixed picture of how important they consider climate risks. Only 10% rank it as their top concern, compared with standard financial and operating risks. But three kinds of climate risks are rapidly rising in urgency:

The risk of new regulations is already having financial consequences for 55% of respondents.

Within two years, 66% fear physical impacts on their assets from extreme weather, rising sea levels or wildfires.

Within five years, 78% expect technological effects, as greener technologies unseat carbon-burning ones.

"The Paris accord means that different countries are going to have to start regulating carbon emissions more," Starks said. "The industry, as a whole, is just in the early stages of tackling this issue."

How do institutional investors feel they can shield themselves? For many, the first step is to assess the problem. Thirty-eight percent are analyzing the carbon footprints of the securities they own, while 24% consider climate risks when screening new investments.

The next step is to talk with corporate managers. While 43% of institutional investors have discussed climate risks in general, 32% have proposed specific actions to shrink carbon footprints.

Respondents aren't always happy with companies' responses. Thirty percent have submitted shareholder proposals such as a successful 2017 resolution that asked Exxon Mobil to disclose how climate risks would affect the company in the future.

A fifth have taken more drastic steps such as publicly criticizing management, taking legal action, or the ultimate punishment: selling off shares.

But for most, it's enough to put executives on notice. "A company becomes more aware of what's in their carbon footprint, because someone is watching," Starks said.

INDIANAPOLIS -- An Indiana University cancer researcher has identified eight new genomic regions that increase a person's risk for skin cancer.

Jiali Han, Ph.D., and colleagues discovered eight new loci--locations on a person's genome--that are susceptible to the development of squamous cell skin cancer. Han is the Rachel Cecile Efroymson Professor in Cancer Research at IU School of Medicine, professor and chair of the Department of Epidemiology at the IU Richard M. Fairbanks School of Public Health at IUPUI, and a researcher at the Indiana University Melvin and Bren Simon Cancer Center.

Researchers previously identified 14 loci with increased risk for squamous cell skin cancer. This study confirmed those findings while adding eight new genomic locations, bringing the total identified risk loci to 22. Their research is published this month online in Nature Communications.

"This is the largest genetic-associated study for squamous cell carcinoma of the skin," Han, an epidemiologist, said. "Our multidisciplinary research sheds light on new biology and the etiology of squamous cell carcinoma, confirming some important genes and also identifying genes involved in this particular cancer development."

Han and colleagues analyzed six international cohorts totaling approximately 20,000 squamous cell skin cancer cases and 680,000 controls, or people who haven't had squamous cell skin cancer. More than one-third of the genomic data came from genetic testing company 23andMe research participants. Additional datasets came from the Nurse's Health Study, Health Professionals Follow-up Study, the Icelandic Cancer Registry and the Ohio State University Division of Human Genetics sample bank.

Research findings confirmed that pigmentation genes can also be a person's skin cancer susceptibility gene, but they also identified additional molecular pathways.

"We can certainly say there is some genetic overlap between squamous cell carcinoma, basal cell carcinoma and melanoma--the three major types of skin cancer--but we also found some genes are specific for squamous cell carcinoma," Han said.

Squamous cell and basal cell are also known as non-melanoma skin cancers. Both usually respond to treatment and rarely spread to other parts of the body, according to the National Cancer Institute. Melanoma is more aggressive, however, and can spread to other parts of the body if it's not diagnosed early.

Physical genomic traits such as fair skin, freckles, blue eyes and brown hair were associated with the risk loci. Researchers have long known that fair skin and sun exposure are risk factors for squamous cell skin cancer.

"Avoiding sun exposure is always the primary prevention strategy, regardless of your skin pigmentation," Han said.

Han and collaborators are continuing to build the population sample to identify more risk loci. Even with the 22 genomic regions identified, the study found those explain only 8.5 percent of the heritable risk for squamous cell skin cancer.

Exposing teeth to excessive fluoride alters calcium signaling, mitochondrial function, and gene expression in the cells forming tooth enamel--a novel explanation for how dental fluorosis, a condition caused by overexposure to fluoride during childhood, arises. The study, led by researchers at NYU College of Dentistry, is published in Science Signaling.

Fluoride is a naturally occurring mineral that helps to prevent cavities by promoting mineralization and making tooth enamel more resistant to acid. It is added to drinking water around the world--the U.S. Department of Health and Human Services recommends a level of 0.7 parts per million--and all toothpastes backed by the American Dental Association's Seal of Acceptance contain fluoride. The Centers for Disease Control and Prevention (CDC) named water fluoridation one of 10 great public health achievements of the 20th century for its role in reducing tooth decay.

While low levels of fluoride help strengthen and protect tooth enamel, too much fluoride can cause dental fluorosis--a discoloration of teeth, usually with opaque white marks, lines, or mottled enamel and poor mineralization. Dental fluorosis occurs when children between birth and around nine years of age are exposed to high levels fluoride during this critical window when their teeth are forming, and can actually increase their risk of tooth decay. A survey by the CDC found that roughly 25 percent of the U.S. population examined (ages 6 to 49) show some degree of dental fluorosis.

"The benefits of fluoride for oral health considerably outweigh the risks. But given how common dental fluorosis is and how poorly understood the cellular mechanisms responsible for this disease are, it is important to study this problem," said Rodrigo Lacruz, PhD, associate professor of basic science and craniofacial biology at NYU College of Dentistry and the study's senior author.

To investigate the molecular bases of dental fluorosis, the researchers analyzed the effects of exposing tooth enamel cells to fluoride--levels on the higher end of what you would find in drinking water and consistent with what is found in areas where people commonly have fluorosis. They then assessed fluoride's impact on calcium signaling within the cells, given calcium's role in mineralizing tooth enamel.

The researchers found that exposing enamel cells from rodents to fluoride resulted in calcium dysregulation, with decreases in calcium entering and stored in the endoplasmic reticulum, a compartment within cells with many functions, including storing calcium. In addition, fluoride disrupted the function of mitochondria (the cells' power generators), and therefore energy production was altered. Finally, RNA sequencing--which queries the genomes of cells--revealed that, in enamel cells exposed to fluoride, there was an increased expression of genes encoding endoplasmic reticulum stress response proteins and those encoding mitochondrial proteins, which are involved in producing the cell's energy.

"This gives us a very promising mechanistic view of how fluorosis arises," Lacruz said. "If your cells have to make enamel, which is heavily calcified, and due to exposure to too much fluoride the cells undergo continued stress in their capacity to handle calcium, that will be reflected in the enamel crystals as they are formed and will impact mineralization."

The researchers then repeated the experiment using early-stage kidney cells from humans, but they did not observe the same effects when the kidney cells were exposed to fluoride--suggesting that enamel cells are different from cells forming tissue in other parts of the body.

"You would think that if you expose the enamel cells and kidney cells to the same stressor--treating them with the same amount of fluoride for the same period of time--that you'd have more or less similar responses. But that was not the case," said Lacruz. "Under the same circumstances, enamel cells react to coping with stress in vastly different ways than kidney cells. We are unraveling a mechanism that highlights the uniqueness of enamel cells and explains why fluorosis is more of a problem in the teeth than anywhere else in the body."

Researchers at North Carolina State University have demonstrated a new, green technology for both accelerated screening and retrieving "switchable" solvents used in green chemistry applications. The new approach makes the screening process hundreds of times faster and drastically accelerates the rate at which solvents can be retrieved from solution.

"We have effectively created a platform that makes green chemistry greener," says Milad Abolhasani, an assistant professor of chemical and biomolecular engineering at NC State and corresponding author of a paper on the work. "This work expedites industry's ability to identify the best switchable solvent for a specific chemical process and then gives industry advanced tools to retrieve that solvent far more quickly than is possible using previous approaches."

At issue are switchable solvents, which change their physicochemical properties when exposed to carbon dioxide (CO2). This study focused on solvents that become hydrophilic in the presence of CO2 and water, but are hydrophobic when CO2 is removed. This makes them attractive for use in chemical and pharmaceutical industry processes, because the solvent can be easily removed from the product by adding CO2 and water. The solvent can then be reclaimed from the water by removing the CO2.

"However, from an industrial point of view, there are significant challenges," Abolhasani says. "Specifically, the process for screening candidates to identify the most efficient switchable solvent for a particular application can be extremely time- and labor-intensive. And once you have the right switchable solvent candidate, removing it on a large scale can also take a long time."

To address the screening problem, Abolhasani's team made use of a microscale flow chemistry platform that runs 5-microliter samples through a gas-permeable tube that is surrounded by CO2. This ensures the solvent in the sample is in constant contact with the CO2 (i.e., intensified mass transfer), accelerating the reaction and the solvent recovery process.

Using this technique, the researchers can determine a solvent's efficiency, using image processing, in as little as three minutes. The platform also allows them to run multiple samples simultaneously. Accounting for the time needed to prepare each sample, the system allows users to run approximately 280 screening experiments per day.

By comparison, conventional batch testing techniques require the use of larger sample sizes. For example, testing the efficiency of a 5-milliliter sample using conventional batch techniques takes between six and eight hours - or approximately one test per day.

Abolhasani's team also demonstrated in experimental testing that the flow chemistry technique was not only faster, but was just as accurate as conventional batch testing at determining a solvent's efficiency.

In addition, the researchers have recently shown that they can reconfigure the same flow chemistry platform utilized for rapid switchable solvent screening into a continuous flow mode for retrieving solvents on a large scale. "Our approach is also more cost effective in that it is completely computer-controlled and is, therefore, less labor-intensive," Abolhasani says.

"We're excited about the potential of this process intensification technology and are looking for partners to help us transfer the technique from the lab to industrial R&D and manufacturing applications."

Let's assume we are dancing on a meadow, quickly spinning about our own axis. At some point we hop on a rotating carousel. We may end up hurting ourselves when both rotations add up and angular momentum is transferred. Are similar phenomena also present in quantum mechanical systems?

After years of preparation, a team at the TU Wien managed to conduct an experiment where the spin of a neutron traverses through a region with a rotating magnetic field. A special kind of coil had to be developed to produce this rotating magnetic field. Although the neutron spin does not carry any mass and can only be described quantum mechanically, it exhibits an inertial property. These results have now been published in Nature Partner Journal Quantum Information.

The Inertia of Rotation: Big Wheels Keep on Turning

"Inertia is a ubiquitous feature", Stephan Sponar of the Institute of Atomic and Subatomic Physics at TU Wien illustrates. "When we sit on a train which moves at constant speed, we cannot tell the difference to a train parked at the station. Only when changing the frame of reference, e.g. when jumping off the train, we are decelerated. We feel forces due to the inertia of our mass."

When rotations are considered, things are similar: the angular momentum of a rotating object is conserved as long as no external torque is applied. But when considering quantum particles, things become more complicated: "Particles like neutrons or electrons feature a special kind of angular momentum - the spin", says Armin Danner, lead author of the newly published paper.

Spin is the intrinsic orbital angular momentum of an elementary particle. There are similarities to the rotation of a planet rotating about its axis, but in many regards this comparison does not hold: the spin is a property of pointlike particles. With a classical mindset, they cannot rotate about any axis. "Spin can be regarded as the angular momentum of an object which is constricted to a point," Armin Danner says. The properties of such a spin are not to be found in our everyday life. But the formalism of quantum mechanics can give us an intuitive idea how things work for some cases.

Coupling Between Spin and Magnetic Field

"Way back in 1988, colleagues already predicted how a neutron should behave when it is suddenly exposed to rotation", Prof. Yuji Hasegawa, head of the neutron interferometry group, explains. "A coupling between the neutron spin and a rotating magnetic field was predicted. But until now, no one could directly demonstrate this coupling in its quantum mechanical form. It also took us a few years of work and several attempts to do that."

Similar to a dancer which has spin and crosses a rotating carousel, the neutron is exposed to a rotating magnetic field. This field manipulates the spin, however, the spin orientations before and after the magnetic field are the same. After traversing the region with the magnetic field, the angular momentum of the neutron is exactly the same as before. The only thing that "happened" to the neutron is that it experienced effects of inertia, which are detectable by means of quantum mechanics.

In the experimental setup, the neutron beam is split into two separated partial beams. One of them is exposed to a rotating field while the other is unaffected. Both partial beams are then recombined. Following the rules of quantum mechanics, the neutron travels along both paths simultaneously. In the first path, effects of inertia locally change the wavelength of the particle-wave. This determines how the partial waves amplify and extinguish each other.

The biggest challenge was the design of the magnetic coil which produces the magnetic field. A small window inside the coil is needed for the neutron beam to pass through. However, the field properties must comply with the strict conditions to induce the desired field. A suitable geometry was identified with the help of computer simulations. The system was developed and tested at the neutron source of the TU Wien in the Viennese Prater while the final measurements were conducted at the ILL in Grenoble, France.

"It is fascinating that we induced a pure quantum effect which at first cannot be understood classically," Armin Danner points out. "Our intuition should therefore not help us here at all. But we could demonstrate for a very specific case that the classical concept of inertia is still valid for the neutron spin."

Breastfeeding affects infant growth and, researchers have found, helps prevent obesity, both in childhood and later in life. However, the components of breast milk responsible for these beneficial effects remain mostly a mystery.

Human milk is an elaborate blend of proteins, fats, minerals and vitamins, plus complex sugar molecules called human milk oligosaccharides, or HMOs. There are approximately 150 types of HMOs. Like thumb and tongue prints, the combination and concentration of HMOs is unique to each nursing mother.

In a new study, published in the February 18, 2020 online issue of The American Journal of Clinical Nutrition, researchers at University of California San Diego School of Medicine confirmed the findings of previous pilot studies that found an association between HMO concentrations and infant weight and body composition.

The earlier pilot studies looked at a smaller, combined cohort of approximately 30 infants who were exclusively breastfed and who displayed excessive weight gain over a period of six months. The UC San Diego study examined a much larger cohort of 802 mothers and their children, part of the longitudinal Steps to Healthy Development of Children (STEPS) study, led by researchers at the University of Turku in Finland. The children were examined from birth to age 5.

The researchers found that high concentrations of one HMO called 2'-Fucosyllactose (2'FL) and low concentrations of another HMO known as Lacto-N-neotetraose (LNnT) were associated with growth in infancy and early childhood. Depending upon concentrations of HMOs in mother's milk, but independent of the mother's pre-pregnancy body mass index or duration of breastfeeding, infant height and weight can vary by half a standard deviation. Standard deviation is a measure of how spread out numbers are.

"We were surprised by the magnitude of the association," said senior author Lars Bode, PhD, professor of pediatrics at UC San Diego School of Medicine and director of the Larsson-Rosenquist Foundation Mother-Milk-Infant Center of Research Excellence. "The impact persisted long after actual exposure to HMOs during breastfeeding. Our analytical platform allows us to measure and associate individual HMOs with specific health and development outcomes."

HMOs are natural prebiotics that contribute to the shaping of the infant gut microbiome, which may affect health and disease risk. But they also act independently of the microbiome, protecting the infant from diseases, such as infectious diarrhea or necrotizing enterocolitis, a serious condition that impacts the intestine of premature infants. HMOs potentially also reduce the risk for non-communicable diseases, such as asthma, allergies and obesity later in life.

"Our goal is to generate a deep mechanistic understanding of how HMOs in a mom's milk can contribute to infant health and development. Although we are only at the very beginning, the generated knowledge provides fascinating new opportunities," said Bode. "Some HMOs could help infants who are behind the growth curve; other HMOs could do the opposite and help lower the risk of childhood obesity. We could even imagine applying HMOs as novel therapeutics for adults who either need to gain weight or suffer from overweight and obesity."

Bode said the study is also an example of how data can help guide the development of HMO blends for different products promoting health. "We could tailor HMO composition in products based on actual scientific evidence and desired outcomes. Much like personalized medicine."

The association results from cohort studies are an impactful way to generate new hypotheses, said the researchers, especially if several different cohorts show very similar associations. However, association studies do not prove causality. Bode said his team's next steps include bringing the data back to the lab to test whether or not HMOs, either alone or in combination, affect growth and to pinpoint the underlying mechanisms.

A team of physicists at the University of Sussex has successfully developed the first nonlinear camera capable of capturing high-resolution images of the interior of solid objects using terahertz (THz) radiation.

Led by Professor Marco Peccianti of the Emergent Photonics (EPic) Lab, Luana Olivieri, Dr Juan S. Totero Gongora and a team of research students built a new type of THz camera capable of detecting THz electromagnetic waves with unprecedented accuracy.

Images produced using THz radiation are called 'hyperspectral' because the image consists of pixels, each one containing the electromagnetic signature of the object in that point.

Lying between microwaves and infrared in the electromagnetic spectrum, THz radiation easily penetrates materials like paper, clothes and plastic in the same way X-rays do, but without being harmful. It is safe to use with even the most delicate biological samples. THz imaging makes it possible to 'see' the molecular composition of objects and distinguish between different materials - such as sugar and cocaine, for example.

Explaining the significance of their achievement, Prof Peccianti said: "The core challenge in THz cameras is not about collecting an image, but it is about preserving the objects spectral fingerprint that can be easily corrupted by your technique. This is where the importance of our achievement lies. The fingerprint of all the details of the image is preserved in such a way that we can investigate the nature of the object in full detail. "

Until now, cameras capable of capturing a hyperspectral image preserving all the fine details revealed by THz radiation had not been considered possible.

The EPic Lab team used a single-pixel camera to image sample objects with patterns of THz light. The prototype they built can detect how the object alters different patterns of THz light. By combining this information with the shape of each original pattern, the camera reveals the image of an object as well as its chemical composition.

Sources of THz radiation are very faint and hyperspectral imaging had, until now, limited fidelity. To overcome this, The Sussex team shone a standard laser onto a unique non-linear material capable of converting visible light to THz. The prototype camera creates THz electromagnetic waves very close to the sample, similar to how a microscope works. As THz waves can travel right through an object without affecting it, the resulting images reveal the shape and composition of objects in three dimensions.

Dr Totero Gongora said: "This is a major step forward because we have demonstrated that all the possibilities explored in our previous theoretical research are not only feasible, but our camera works even better than we expected. While building our device, we discovered several ways to optimise the imaging process and now the technology is stable and works well. The next phase of our research will be in speeding up the image reconstruction process and taking us closer to applying THz cameras to real-world applications; like airport security, intelligent car sensors, quality control in manufacturing and even scanners to detect health problems like skin cancer."

Since 2013, the Antarctic neutrino telescope IceCube has been detecting neutrinos that come from deep space. However, IceCube struggles to detect neutrinos with energies above 10¹? electronvolts because of the extremely low flux of these neutrinos at Earth. Now, researchers have obtained the first measurements of "radar echoes" from high energy particle cascades using a high energy electron beam at the SLAC National Accelerator Laboratory. Radar echoes are radio waves reflected from a conducting surface. Cascades occur when an ultra high energy particle interacts with material, producing other particles that move at roughly the speed of light and ionizing the material. By bouncing radio waves off that ionization, Prohira et al. created a detectable radar echo that can be used to detect the cascade itself. The new radar echo detection method could help scientists create a neutrino telescope complementary to existing technology in the detection of high energy neutrinos.

As the Democractic primaries accelerate and the 2020 presidential election approaches, many Americans still remember Russia's interference in the 2016 presidential election. Scientists have now developed a game theory model able to capture and assess election interference. Dewhurst et al. first created rational game players that were assigned different parameters. For example, in one scenario players' were programmed to have all-or-nothing attitudes, which lead them to an escalating election interference "arms race." Then, the researchers introduced a method for developing potential solutions for election interference. By using Russia's interference in the 2016 US elections as a case study, the researchers tested the model's ability to accurately capture election interference. The results reflected election activity similar to those found during the 2016 election polls and by social media posts by Russian Twitter fake accounts--both relevant areas of concern for the 2020 election.

Winds outside of Tropical Storm Gabekile are ripping the storm apart. NASA's Aqua satellite provided a visible image of the storm that showed strong northwesterly wind shear was adversely affecting the storm.

Gabekile formed on Feb. 15 and by the next day, it had rapidly intensified to hurricane-force with maximum sustained winds near 75 knots (86 mph/139 kph), then after encountering wind shear the storm quickly weakened.

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.

When NASA's Aqua satellite passed over the Southern Indian Ocean, it provided forecasters with a visible image of the tropical depression. On Feb. 18 at 3:30 a.m. EST (830 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite showed wispy clouds circled around Gabekile's low-level center and the bulk of clouds and storms were pushed more than 100 nautical miles southeast of the center.

At 10 a.m. EST (1500 UTC), the Joint Typhoon Warning Center (JTWC) issued the final bulletin on Gabekile. Tropical cyclone Gabekile had maximum sustained winds near 30 knots (34.5 mph/55.5 kph), making it a tropical depression. Gabekile was located near latitude 21.0 degrees south and longitude 75.5 degrees east, about 852 nautical miles south of Diego Garcia. Gabekile was moving to the south-southwest and dissipating.

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

Tropical cyclones/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.

Scientists at the U.S. Department of Energy's Ames Laboratory have discovered that applying vibrational motion in a periodic manner may be the key to preventing dissipations of the desired electron states that would make advanced quantum computing and spintronics possible.

Some topological materials are insulators in their bulk form, but possess electron-conducting behavior on their surfaces. While the differences in the behavior of these surface electrons is what makes these materials so promising for technological applications, it also presents a challenge: uncontrolled interactions between surface electrons and the bulk material states can cause electrons to scatter out of order, leading to so-called "topological breakdown". They are not protected by any "spontaneous" symmetry.

"Topological insulators that can sustain a persistent spin-locked current on their surfaces which does not decay are termed 'symmetry protected,' and that state is compelling for multiple revolutionary device concepts in quantum computing and spintronics," said Jigang Wang, Ames Laboratory physicist and Iowa State University professor. "But the topological breakdown due to surface-bulk coupling is a long standing scientific and engineering problem."

Wang and his fellow researchers took a paradoxical approach, called dynamic stabilization, by applying a terahertz electric field to drive periodic atomic vibrations, i.e., vibrational coherence, in the model topological insulator bismuth-selenium Bi2Se3. These extra "fluctuations" actually enhanced protected topological states, making the electronic excitations longer lived.

An analogy of such dynamic stabilization is the periodically driven Kapitza pendulum, known by Nobel Laureate Peter Kapitza, where an inverted, yet stable, orientation is achieved by imposing a sufficiently high-frequency vibration of its pivot point. In a similar manner, additional dynamic stabilization can be achieved by driving quantum periodic motions of the lattice.

"We demonstrate the dynamic stabilization in topological matter as a new universal tuning knob, that can be used to reinforce protected quantum transport," said Wang, who believes the discovery has far-reaching consequences for the use of these materials to many scientific and technological disciplines, such as disorder-tolerant quantum information and communications applications and spin-based, lightwave quantum electronics.

It takes a lot of fuel to launch something into space. Sending NASA's Space Shuttle into orbit required more than 3.5 million pounds of fuel, which is about 15 times heavier than a blue whale.

But a new type of engine -- called a rotating detonation engine -- promises to make rockets not only more fuel-efficient but also more lightweight and less complicated to construct. There's just one problem: Right now this engine is too unpredictable to be used in an actual rocket.

Researchers at the University of Washington have developed a mathematical model that describes how these engines work. With this information, engineers can, for the first time, develop tests to improve these engines and make them more stable. The team published these findings Jan. 10 in Physical Review E.

"The rotating detonation engine field is still in its infancy. We have tons of data about these engines, but we don't understand what is going on," said lead author James Koch, a UW doctoral student in aeronautics and astronautics. "I tried to recast our results by looking at pattern formations instead of asking an engineering question -- such as how to get the highest performing engine -- and then boom, it turned out that it works."

A conventional rocket engine works by burning propellant and then pushing it out of the back of the engine to create thrust.

"A rotating detonation engine takes a different approach to how it combusts propellant," Koch said. "It's made of concentric cylinders. Propellant flows in the gap between the cylinders, and, after ignition, the rapid heat release forms a shock wave, a strong pulse of gas with significantly higher pressure and temperature that is moving faster than the speed of sound.

"This combustion process is literally a detonation -- an explosion -- but behind this initial start-up phase, we see a number of stable combustion pulses form that continue to consume available propellant. This produces high pressure and temperature that drives exhaust out the back of the engine at high speeds, which can generate thrust."

Conventional engines use a lot of machinery to direct and control the combustion reaction so that it generates the work needed to propel the engine. But in a rotating detonation engine, the shock wave naturally does everything without needing additional help from engine parts.

"The combustion-driven shocks naturally compress the flow as they travel around the combustion chamber," Koch said. "The downside of that is that these detonations have a mind of their own. Once you detonate something, it just goes. It's so violent."

To try to be able to describe how these engines work, the researchers first developed an experimental rotating detonation engine where they could control different parameters, such as the size of the gap between the cylinders. Then they recorded the combustion processes with a high-speed camera. Each experiment took only 0.5 seconds to complete, but the researchers recorded these experiments at 240,000 frames per second so they could see what was happening in slow motion.

From there, the researchers developed a mathematical model to mimic what they saw in the videos.

"This is the only model in the literature currently capable of describing the diverse and complex dynamics of these rotating detonation engines that we observe in experiments," said co-author J. Nathan Kutz, a UW professor of applied mathematics.

The model allowed the researchers to determine for the first time whether an engine of this type would be stable or unstable. It also allowed them to assess how well a specific engine was performing.

"This new approach is different from conventional wisdom in the field, and its broad applications and new insights were a complete surprise to me," said co-author Carl Knowlen, a UW research associate professor in aeronautics and astronautics.

Right now the model is not quite ready for engineers to use.

"My goal here was solely to reproduce the behavior of the pulses we saw -- to make sure that the model output is similar to our experimental results," Koch said. "I have identified the dominant physics and how they interplay. Now I can take what I've done here and make it quantitative. From there we can talk about how to make a better engine."

UCLA researchers have found that it is possible to assess a person's ability to feel empathy by studying their brain activity while they are resting rather than while they are engaged in specific tasks.

Traditionally, empathy is assessed through the use of questionnaires and psychological assessments. The findings of this study offer an alternative to people who may have difficulty filling out questionnaires, such as people with severe mental illness or autism, said senior author Dr. Marco Iacoboni, professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA.

"Assessing empathy is often the hardest in the populations that need it most," Iacoboni said. "Empathy is a cornerstone of mental health and well-being. It promotes social and cooperative behavior through our concern for others. It also helps us to infer and predict the internal feelings, behavior and intentions of others."

Iacoboni has long studied empathy in humans. His previous studies have involved testing empathy in people presented with moral dilemmas or watching someone in pain.

For the current study, published in Frontiers in Integrative Neuroscience, researchers recruited 58 male and female participants ages 18 to 35.

Resting brain activity data were collected using functional magnetic resonance imaging, or fMRI, a noninvasive technique for measuring and mapping brain activity through small changes in blood flow. Participants were told to let their minds wander while keeping their eyes still, by looking at a fixation cross on a black screen.

Afterward, the participants completed questionnaires designed to measure empathy. They rated how statements such as "I often have tender, concerned feelings for people less fortunate than me" and "I sometimes try to understand my friends better by imagining how things look from their perspective" described them on a five-point scale from "not well" to "very well."

Researchers wanted to measure how accurately they could predict the participants' empathic disposition, characterized as the willingness and ability to understand another's situation, by analyzing the brain scans.

The predictions were made by looking into resting activity in specific brain networks that earlier studies demonstrated are important for empathy. Researchers used a form of artificial intelligence called machine learning, which can pick up subtle patterns in data that more traditional data analyses might not.

"We found that even when not engaged directly in a task that involves empathy, brain activity within these networks can reveal people's empathic disposition," Iacoboni said. "The beauty of the study is that the MRIs helped us predict the results of each participant's questionnaire."

The findings could help health care professionals better assess empathy in people with autism or schizophrenia, who may have difficulties filling out questionnaires or expressing emotion.

"People with these conditions are thought to lack empathy," he said. "But if we can demonstrate that their brains have the capability for empathy, we can work to improve it through training and the use of other therapies."

Furthermore, said lead author Leonardo Christov-Moore, a postdoctoral fellow currently at USC's Brain and Creativity Institute, this technique may be expanded to improve treatment as well as diagnosis.

"The predictive power of machine learning algorithms like this one, when applied to brain data, can also help us predict how well a given patient will respond to a given intervention, helping us tailor optimal therapeutic strategies from the get-go."

The study adds to a growing body of research suggesting that brains at rest are as active as brains engaged in a task, and that brain networks in the resting brain may interact in a similar fashion as when they are engaged in a task.

Iacoboni said future, larger studies may help identify other regions of the brain associated with empathy.