Tech

Scientists have developed a new technique using tools made of luminescent DNA, lit up like fireflies, to visualize the mechanical forces of cells at the molecular level. Nature Methods published the work, led by chemists at Emory University, who demonstrated their technique on human blood platelets in laboratory experiments.

"Normally, an optical microscope cannot produce images that resolve objects smaller than the length of a light wave, which is about 500 nanometers," says Khalid Salaita, Emory professor of chemistry and senior author of the study. "We found a way to leverage recent advances in optical imaging along with our molecular DNA sensors to capture forces at 25 nanometers. That resolution is akin to being on the moon and seeing the ripples caused by raindrops hitting the surface of a lake on the Earth."

Almost every biological process involves a mechanical component, from cell division to blood clotting to mounting an immune response. "Understanding how cells apply forces and sense forces may help in the development of new therapies for many different disorders," says Salaita, whose lab is a leader in devising ways to image and map bio-mechanical forces.

The first authors of the paper, Joshua Brockman and Hanquan Su, did the work as Emory graduate students in the Salaita lab. Both recently received their PhDs.

The researchers turned strands of synthetic DNA into molecular tension probes that contain hidden pockets. The probes are attached to receptors on a cell's surface. Free-floating pieces of DNA tagged with fluorescence serve as imagers. As the unanchored pieces of DNA whizz about they create streaks of light in microscopy videos.

When the cell applies force at a particular receptor site, the attached probes stretch out causing their hidden pockets to open and release tendrils of DNA that are stored inside. The free-floating pieces of DNA are engineered to dock onto these DNA tendrils. When the florescent DNA pieces dock, they are briefly demobilized, showing up as still points of light in the microscopy videos.

Hours of microscopy video are taken of the process, then speeded up to show how the points of light change over time, providing the molecular-level view of the mechanical forces of the cell.

The researchers use a firefly analogy to describe the process.

"Imagine you're in a field on a moonless night and there is a tree that you can't see because it's pitch black out," says Brockman, who graduated from the Wallace H. Coulter Department of Biomedical Engineering, a joint program of Georgia Tech and Emory, and is now a post-doctoral fellow at Harvard. "For some reason, fireflies really like that tree. As they land on all the branches and along the trunk of the tree, you could slowly build up an image of the outline of the tree. And if you were really patient, you could even detect the branches of the tree waving in the wind by recording how the fireflies change their landing spots over time."

"It's extremely challenging to image the forces of a living cell at a high resolution," says Su, who graduated from Emory's Department of Chemistry and is now a post-doctoral fellow in the Salaita lab. "A big advantage of our technique is that it doesn't interfere with the normal behavior or health of a cell."

Another advantage, he adds, is that DNA bases of A, G, T and C, which naturally bind to one another in particular ways, can be engineered within the probe-and-imaging system to control specificity and map multiple forces at one time within a cell.

"Ultimately, we may be able to link various mechanical activities of a cell to specific proteins or to other parts of cellular machinery," Brockman says. "That may allow us to determine how to alter the cell to change and control its forces."

By using the technique to image and map the mechanical forces of platelets, the cells that control blood clotting at the site of a wound, the researchers discovered that platelets have a concentrated core of mechanical tension and a thin rim that continuously contracts. "We couldn't see this pattern before but now we have a crisp image of it," Salaita says. "How do these mechanical forces control thrombosis and coagulation? We'd like to study them more to see if they could serve as a way to predict a clotting disorder."

Just as increasingly high-powered telescopes allow us to discover planets, stars and the forces of the universe, higher-powered microscopy allows us to make discoveries about our own biology.

"I hope this new technique leads to better ways to visualize not just the activity of single cells in a laboratory dish, but to learn about cell-to-cell interactions in actual physiological conditions," Su says. "It's like opening a new door onto a largely unexplored realm -- the forces inside of us."

EVANSTON, Ill. --- All animals great and small live every day in an uncertain world. Whether you are a human being or an insect, you rely on your senses to help you navigate and survive in your world. But what drives this essential sensing?

Unsurprisingly, animals move their sensory organs, such as eyes, ears and noses, while they are searching. Picture a cat swiveling its ears to capture important sounds without needing to move its body. But the precise position and orientation these sense organs take over time during behavior is not intuitive, and current theories do not predict these positions and orientations well.

Now a Northwestern University research team has developed a new theory that can predict the movement of an animal's sensory organs while searching for something vital to its life.

The researchers applied the theory to four different species which involved three different senses (including vision and smell) and found the theory predicted the observed sensing behavior of each animal. The theory could be used to improve the performance of robots collecting information and possibly applied to the development of autonomous vehicles where response to uncertainty is a major challenge.

"Animals make their living through movement," said Malcolm A. MacIver, who led the research. "To find food and mates and to identify threats, they need to move. Our theory provides insight into how animals gamble on how much energy to expend to get the useful information they need."

MacIver is a professor of biomedical and mechanical engineering in Northwestern's McCormick School of Engineering and a professor of neurobiology (courtesy appointment) in the Weinberg College of Arts and Sciences.

The new theory, called energy-constrained proportional betting provides a unifying explanation for many enigmatic motions of sensory organs that have been previously measured. The algorithm that follows from the theory generates simulated sensory organ movements that show good agreement to actual sensory organ movements from fish, mammals and insects.

The study was published today (Sept. 22) by the journal eLife. The research provides a bridge between the literature on animal movement and energetics and information theory-based approaches to sensing.

MacIver is the corresponding author. Chen Chen, a Ph.D. student in MacIver's lab, is the first author, and Todd D. Murphey, professor of mechanical engineering at McCormick, is a co-author.

The algorithm shows that animals trade the energetically costly operation of movement to gamble that locations in space will be informative. The amount of energy (ultimately food they need to eat) they are willing to gamble, the researchers show, is proportional to the expected informativeness of those locations.

"While most theories predict how an animal will behave when it largely already knows where something is, ours is a prediction for when the animal knows very little -- a situation common in life and critical to survival," Murphey said.

The study focuses on South American gymnotid electric fish, using data from experiments performed in MacIver's lab, but also analyzes previously published datasets on the blind eastern American mole, the American cockroach and the hummingbird hawkmoth. The three senses were electrosense (electric fish), vision (moth) and smell (mole and roach).

The theory provides a unified solution to the problem of not spending too much time and energy moving around to sample information, while getting enough information to guide movement during tracking and related exploratory behaviors.

"When you look at a cat's ears, you'll often see them swiveling to sample different locations of space," MacIver said. "This is an example of how animals are constantly positioning their sensory organs to help them absorb information from the environment. It turns out there is a lot going on below the surface in the movement of sense organs like ears and eyes and noses."

The algorithm is a modified version of one Murphey and MacIver developed five years ago in their bio-inspired robotics work. They took observations of animal search strategies and developed algorithms to have robots mimic those animal strategies. The resulting algorithms gave Murphey and MacIver concrete predictions for how animals might behave when searching for something, leading to the current work.

Tropical Storm Paulette just reformed in the central North Atlantic Ocean today, Sept. 22. Using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Paulette's rainfall rates.

Paulette was a hurricane whose eye passed directly over Bermuda, then weakened and became a post-tropical cyclone on Sept. 16 in the North Atlantic Ocean when it was located 450 miles (725 km) east-southeast of Cape Race Newfoundland, Canada. A Post-Tropical Storm is a generic term for a former tropical cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone.

At 11 a.m. EDT (1500 UTC) on Sept.16 NOAA's National Hurricane Center (NHC) issued the final advisory on Paulette but tracked its remnants over the last 6 days. NHC forecasters had assigned a medium chance that Paulette could redevelop over that time. At 11 p.m. EDT on Sept. 21 (0300 UTC on Sept. 22), Paulette regained tropical characteristics.

Paulette's Status on Sept. 22

At 5 a.m. EDT (0900 UTC) on Sept. 22, the center of Tropical Storm Paulette was located near latitude 34.7 degrees north and longitude 23.7 degrees west. That is about 295 miles (470 km) southeast of the Azores Islands. The Azores islands are an autonomous region of Portugal in the mid-Atlantic.

Paulette was moving toward the east-northeast near 17 mph (28 kph). An east or east-northeast motion at a slower forward speed is expected through Wednesday. Paulette is then expected to turn southward and southwestward Wednesday night and Thursday.

Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Weakening is forecast during the next couple of days, and Paulette is expected to become post-tropical by Wednesday night or Thursday. The estimated minimum central pressure is 1002 millibars.

Estimating Paulette's Rainfall Rates from Space

At 11 p.m. EDT on Sept. 21, deep convection and thunderstorm development associated with the post-tropical remnants of Paulette had become better organized over the past 6 to 12 hours. "An ASCAT over pass from a few hours ago indicate that increase in convective organization has resulted in strengthening and the system is being classified as a tropical cyclone once again," noted Daniel Brown, senior hurricane specialist and warning coordination meteorologist at NOAA's National Hurricane Center in Miami, Fla.

Four and a half hours later, NASA's Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated rainfall occurring in the newly reformed tropical storm. On Sept. 22 at 3:30 a.m. EDT (0730 UTC) IMERG formed Paulette was generating as much as 5 mm (0.20 inches) of rain per hour around the center of circulation.

By 5 a.m. EDT (0900 UTC), the NHC noted that the tops of Paulette's convective clouds have been warming since the previous advisory, and first-light visible images showed that a swirl of low- to mid-level clouds is about all that is left.

At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from NOAA's GOES-16 satellite to provide a full extent of the storm.

What Does IMERG Do?

This near-real time rainfall estimate comes from the NASA's IMERG, which combines observations from a fleet of satellites, in near-real time, to provide near-global estimates of precipitation every 30 minutes. By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.

What the IMERG does is "morph" high-quality satellite observations along the direction of the steering winds to deliver information about rain at times and places where such satellite overflights did not occur. Information morphing is particularly important over the majority of the world's surface that lacks ground-radar coverage. Basically, IMERG fills in the blanks between weather observation stations.

NASA Researches Tropical Cyclones

Hurricanes/tropical cyclones 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.

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

For more information about NASA's IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For forecast updates on hurricanes, visit: http://www.hurricanes.gov

NASA's Aqua satellite used infrared light to identify strongest storms and coldest cloud top temperatures in Hurricane Teddy as it nears eastern Canada. Teddy has triggered multiple warnings and watches.

Warnings and Watches on Sept. 22

NOAA's National Hurricane Center noted that a Tropical Storm Warning is in effect for the south coast of Nova Scotia from Digby to Meat Cove, Canada.

A Tropical Storm Watch is in effect from Meat Cove to Tidnish, Nova Scotia, from north of Digby to Fort Lawrence, Nova Scotia. A Watch is also in effect for the Magdalen Islands, Quebec, for Port aux Basques to Francois, Newfoundland and for Prince Edward Island.

Infrared Data Reveals Powerful Storms

On Sept. 22 at 1:55 a.m. EDT (0555 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS aboard NASA's Aqua satellite gathered temperature information about Teddy's cloud tops. MODIS found the most powerful thunderstorms were in a very small area near the center where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Most of the rest of the storm had cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Recent satellite imagery shows that the central convection is diminishing, with a comma-like cloud pattern developing.

Teddy' Status on Sept. 22

At 8 a.m. EDT (1200 UTC) on Sept. 22, the center of Hurricane Teddy was located near latitude 39.3 degrees north and longitude 63.5 degrees west. That is about 365 miles (590 km) south of Halifax, Nova Scotia, Canada.

Teddy is moving toward the north-northwest near 28 mph (44 kph), and a turn toward the north-northeast is expected by early Wednesday. Maximum sustained winds are near 105 mph (165 kph) with higher gusts. Teddy is a large hurricane. Hurricane-force winds extend outward up to 105 miles (165 km) from the center and tropical-storm-force winds extend outward up to 400 miles (645 km). The estimated minimum central pressure is 950 millibars.

Teddy's Forecast

On the forecast track, the center will move over eastern Nova Scotia on Wednesday, Sept. 23 and then near or over Newfoundland by Wednesday night. Although some weakening is likely later today and Wednesday, Teddy should be a strong post-tropical cyclone when it moves near and over Nova Scotia.

NHC Key Messages

The National Hurricane Center's key messages are:

WIND: Tropical storm conditions are expected to begin in the warning area by this afternoon.  Tropical storm conditions could begin in the watch areas late today or early Wednesday.
SURF: Large swells generated by Teddy are affecting Bermuda, the Lesser Antilles, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada. These swells are likely to cause life-threatening surf and rip current conditions.
RAINFALL: Through Thursday, Teddy is expected to produce rainfall accumulations of 2 to 4 inches (50 to 100 mm) with isolated totals of 6 inches (150 mm) across sections of Atlantic Canada.
STORM SURGE: A dangerous storm surge is expected to produce significant coastal flooding near and to the east of where the center makes landfall in Nova Scotia.  Near the coast, the surge will be accompanied by very large and destructive waves.

NASA Researches Tropical Cyclones

Hurricanes/tropical cyclones 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.

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

For updated forecasts, visit: http://www.hurricanes.gov

NASA analyzed the cloud top temperatures in Tropical Storm Lowell using infrared light to determine the strength of the storm. Infrared imagery revealed that the strongest storms were around Lowell's center and in its southern quadrant because of northerly wind shear.

Tropical Storm Lowell developed about 500 miles away from Baja California, Mexico. On Sept. 21, it formed as Tropical Depression 17E. By 5 p.m. EDT, the depression organized and strengthened into a tropical storm and was renamed Lowell.

Lowell is Battling Wind Shear

"Lowell continues to be affected by north-northeasterly shear, and the center is estimated to be located near the north-northeastern edge of the main convective mass," said Senior Hurricane Specialist Richard Pasch at NOAA's National Hurricane Center in Miami, Fla.

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.

An Infrared View of Lowell

One of the ways NASA researches tropical cyclones is using infrared data that provides temperature information. Cloud top temperatures identify where the strongest storms are located. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures.

On Sept. 22 at 4:15 a.m. EDT (0915 UTC) NASA's Aqua satellite analyzed the storm using the Moderate Resolution Imaging Spectroradiometer or MODIS instrument. The MODIS imagery showed the strongest storms were around Lowell's center of circulation and pushed into its southern quadrant. Temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). An area of strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

NASA then provides data to tropical cyclone meteorologists so they can incorporate it in their forecasts.

Lowell's Status on Sept. 22

At 5 a.m. EDT (0900 UTC) on Sept. 22, the center of Tropical Storm Lowell was located near latitude 18.0 degrees north and longitude 115.6 degrees west. That is about 500 miles (805 km) southwest of the southern tip of Baja California, Mexico. Lowell is moving toward the west-northwest near 13 mph (20 kph). Maximum sustained winds are near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1001 millibars.

Lowell's Forecast

Some strengthening is forecast during the next couple of day as Lowell continues to move away from land areas and in a west-northwest direction followed by a turn toward the west. Lowell is no threat to land areas.

NASA Researches Earth from Space

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

For updated forecasts, visit: http://www.hurricanes.gov

By Rob Gutro
NASA's Goddard Space Flight Center

DETROIT - Dermatology researchers at Henry Ford Health System, in collaboration with a team at the University of Michigan, have demonstrated that certain N95 respirators tainted with COVID-19 can be effectively and safely decontaminated for reuse using ultraviolet-C light (UV-C), a method commonly utilized for treating rare skin diseases.

Researchers say the outside and inside of the facemasks were decontaminated in a prototype phototherapy unit that dispenses a UV-C dosing level high enough to effectively kill the virus in less than two minutes while still preserving the facemask's breathability, fit and overall integrity.

Of the five N95s used at Henry Ford and tested for the coronavirus in the study, the decontamination process worked best on two models - facepieces on 3M 1860 and Moldex 1511 and straps on 3M 8210 and Moldex 1511. The effects of the dosage varied on the other tested models and their straps, suggesting that the UV-C radiation can degrade them. Researchers say wiping the straps with ethanol before decontamination would likely be required as an additional disinfection step in the process to maximize the wearer's safety.

Researchers emphasized that fit testing be required each time a disinfected facemask is returned for use or a new model is being worn for the first time.

The research, conducted in partnership with the University of Michigan, is published in the International Journal of Infectious Diseases.

"Our findings reveal a practical, and viable option should hospitals encounter shortages of N95s in the future," says David Ozog, M.D., chair of Henry Ford's Department of Dermatology in Detroit and the study's lead author. "Using UV-C has been shown to be effective in killing other coronaviruses and the flu virus. We were able to replicate that sterilization effectiveness with COVID-19."

Ozog stressed that facemask sterilization should only be used in severe shortages of N95s.

Testing of the N95s for decontamination was performed at U-M's SARS-CoV-2 research lab in Ann Arbor.

"When Dr. Ozog approached us about helping to demonstrate the effectiveness of their UV sterilization procedure with live SARS-CoV-2 virus, we immediately agreed and understood that we could provide some confidence to their healthcare workers that this procedure was effective," says Jonathan Sexton, Ph.D., assistant professor of Internal Medicine and director of the U-M Center for Drug Repurposing and a study co-author.

The research culminated the work of a team of dermatologists and researchers who have devoted more than 400 hours since the pandemic hit Michigan to investigating how phototherapy - a type of medical treatment used for treating certain skin conditions - could serve a role in the global health emergency. The Henry Ford team includes Henry Lim, M.D., and Iltefat Hamzavi, M.D., both of whom are internationally recognized for their expertise using phototherapy for treating rare skin diseases like vitiligo and hidradenitis suppurativa.

The team's focus centered on the potential of decontamination contaminated N95s for reuse by healthcare workers. They examined the reliability of the prototype unit and ultraviolet light, the minimum dosage needed for decontamination, the importance of fit testing post-decontamination and four common methods associated with facemask decontamination.

The pandemic exposed a critical flaw in the global PPE supply chain as the health care industry struggled to obtain supplies of N95s, other facemask types, gowns, gloves and face shields. As a result, decontaminating N95s to be reused safely became essential for many health care systems and providers until new shipments of supplies arrived. Henry Ford decontaminated thousands of N95s and returned them to their user for reuse in the first couple months of the pandemic.

"The beginning of the pandemic was physically and mentally overwhelming for everyone. We desperately wanted to help our front-line workers, who were crushed with COVID-19 cases at Henry Ford," Dr. Ozog says.

UV-C is one of the four methods considered for facemask decontamination. It is well known for its ability to penetrate the DNA of bacteria and microorganisms and prevent them from multiplying or replicating. Previous research has shown UV-C to be effective at killing the flu virus as well two other well- known coronaviruses: severe acute respiratory syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS-CoV). Whether it could work on the novel COVID-19 virus was previously unknown.

Henry Ford's phototherapy unit was modified with the help of engineers at Daavlin Co., a phototherapy manufacturer based in Bryan, Ohio. It sits on a flat surface and is about five feet long. The decontamination field measures 15 inches deep by 45 inches long - plenty room to treat up to 27 facemasks at one time. The ultraviolet light is powered by at least 10 but not more than 20 UV-C lamps.

For the study, five types of N95s used at Henry Ford were tested at the U-M BSL3 biosafety lab. The respirators were contaminated with four drops of the COVID-19 virus taken from viral stocks obtained from the federal government's Biodefense and Emergency Infections Research Resources Repository. The virus droplets were placed in four areas: nosepiece, apex, chin and strap.

The facemasks were kept dry in a biosafety cabinet at room temperature for 40 minutes. Then they were moved to the phototherapy unit for decontamination using a dose of 1.5 J/cm2 ultraviolet light radiation - at a wavelength of 254 nanometers - to each side of the mask for about 60 seconds. Ultraviolet radiation is measured in three wavelengths: UV-C, UV-B and UV-A. UV-B and UV-A are associated with skin cancer and are also used in the treatment of some dermatologic diseases such as vitiligo and psoriasis.

Indermeet Kohli, Ph.D, a Henry Ford dermatology physicist, developed a formula by which the UV-C dose delivered to the exterior and interior parts of the facemasks can be assessed for decontamination and safe use. She says the curvature of the facemask and the distance between its surface and the lamps are crucial factors in achieving the proper dosage.

"It is imperative that this type of assessment be performed to make sure that the decontamination process is done properly," Dr. Kohli says. "Failure to do so could result in catastrophic consequences for the front-line healthcare workers."

The effectiveness of decontamination was measured in analytical chemistry terms by the limit of detection (LOD) and no cytopathic effect (CPE). LOD is the minimum concentration of a component that can be reliably detected. CPE means the virus yielded no infectious properties.

All five facepieces had below LOD and no CPE but some had traces of the virus on their straps, according to the research.

Researchers cautioned that none of the N95s tested were visibly soiled. Most health systems including Henry Ford prohibit the reuse of soiled N95s.

In a Letter to the Editor published in Photodermatology, Photoimmunology & Photomedicine, Shanthi Narla, M.D., a Henry Ford dermatology fellow, urged caution about using UV-C decontamination due to the variety of N95s in use across the country. "This process should only be considered as a risk mitigation effort during severe shortages," she wrote.

In a demonstration of the prototype unit, the facemasks are placed on a stainless-steel tray, separated by autoclave tape to keep them from touching each other. Once one side of the facemask is treated, it's flipped over to perform a separate decontamination. Researchers say any visibly soiled masks should not be treated but rather properly disposed as medical waste.

"Considering that many healthcare providers are using substitutes for N95s that offer very limited degree of protection, using (UV-C) and repurposing phototherapy devices could be the best practical solution at this time," Dr. Hamzavi wrote in Letter to the Editor published online in JAAD.

Researchers stressed that not all N95s are created equal and may not withstand decontamination. Degrading may occur in the facemask's outer surface and the elasticity of the bands. Thus, researchers underscored the importance of fit-testing after decontamination in a study published in the Journal of the American Academy of Dermatology. Health care workers are fit-tested every year with their N95 to ensure a proper fit and no air can penetrate the outer edges.

UV-C is one of the four common methods used in health care to sterilize N95s. Hydrogen peroxide vaporization, microwave generated steaming and dry heating also have shown to be effective in varying degrees. UV-C and HPV are also commonly used for disinfecting patient care units, surgical suites and intensive care units in the health care setting. Only the UV-C method was used in the Henry Ford study.

Researchers strike a cautionary tone for N95 decontamination no matter the method.

"Given the current COVID-19 pandemic, extreme measures are needed to keep those on the front line protected," says Angela Torres, M.D., a Henry Ford dermatology fellow and lead author in a study published online in Photochemical & Photobiological Sciences. "These options are cost effective, quick to employ and have the potential to save many lives and valuable resources."

However, Dr. Torres says, discarding a contaminated disposable N95 after a single use is "still ideal."

Interactions between individuals of the same species shape many aspects of their biology, including their social behaviour. Social genetic effects occur when the phenotype of an individual, defined as a set of their observable characteristics, is affected by the genetic features of others from the same species. These effects are common and imply consequences for the evolutionary history or health state of many animal species.

A team of researchers led by Rui Oliveira studied the role of oxytocin, an important molecule for the regulation of social bonding. Using the zebrafish (Danio rerio) as a model organism, they aimed at understanding how social genetic effects impact the interaction between the individual and the social environment or, in this case, the shoal. For that purpose, the team used two kinds of zebrafish: ones similar to the ones found in nature and others in which the oxytocin gene was removed, thus rendered no longer functional.

Placed in the presence of a shoal that was genetically similar to them or not, the individuals were assessed in their (1) social preference, which describes their motivation to approach the similar shoal, (2) social recognition, which focuses on the individual ability to distinguish between different shoals, and (3) social integration and influence, which quantify, respectively, how well the individual can integrate himself in a shoal and how much it can influence its behaviour.

The results of the study show that both the social preference and social integration and influence change depending on whether the shoal has oxytocin or not. On the contrary, it's the genetic features of the individual that determine the ability to create memories and therefore distinguish between different shoals. "The genetic differences of the social group interact with the ones of the individual during the acquisition of social behaviours and development, and in some cases they can revert behavioural characteristics associated to oxytocin", explains Rui Oliveira.

In addition to being the last horizon for adventurers and spiritual seekers, the Himalaya region is a prime location for understanding geological processes. It hosts world-class mineral deposits of copper, lead, zinc, gold and silver, as well as rarer elements like lithium, antimony and chrome, that are essential to modern technology. The uplift of the Tibetan plateau even affects global climate by influencing atmospheric circulation and the development of seasonal monsoons.

Yet despite its importance, scientists still don't fully understand the geological processes contributing to the region's formation. "The physical and political inaccessibility of Tibet has limited scientific study, so most field experiments have either been too localized to understand the big picture or they've lacked sufficient resolution at depths to properly understand the processes," said Simon Klemperer, a geophysics professor at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth).

Now, new seismic data gathered by Klemperer and his colleagues provides the first west-to-east view of the subsurface where India and Asia collide. The research contributes to an ongoing debate over the structure of the Himalaya collision zone, the only place on Earth where continental plates continue crashing today - and the source of catastrophes like the 2015 Gorkha earthquake that killed about 9,000 people and injured thousands more.

The new seismic images suggest that two competing processes are simultaneously operating beneath the collision zone: movement of one tectonic plate under another, as well as thinning and collapse of the crust. The research, conducted by scientists at Stanford University and the Chinese Academy of Geological Sciences, was published in Proceedings of the National Academy of Sciences Sept. 21.

The study marks the first time that scientists have collected truly credible images of what's called an along-strike, or longitudinal, variation in the Himalaya collision zone, co-author Klemperer said.

As the Indian plate collides with Asia it forms Tibet, the highest and largest mountain plateau on the planet. This process started very recently in geological history, about 57 million years ago. Researchers have proposed various explanations for its formation, such as a thickening of the Earth's crust caused by the Indian plate forcing its way beneath the Tibetan Plateau.

To test these hypotheses, researchers began the major logistical effort of installing new seismic recorders in 2011 in order to resolve details that might have been previously overlooked. Importantly, the new recorders were installed from east to west across Tibet; traditionally, they had only been deployed from north to south because that is the direction the country's valleys are oriented and thus the direction that roads have historically been built.

The final images, pieced together from recordings by 159 new seismometers closely spaced along two 620-mile long profiles, reveal where the Indian crust has deep tears associated with the curvature of the Himalayan arc.

"We're seeing at a much finer scale what we never saw before," Klemperer said. "It took a heroic effort to install closely spaced seismometers across the mountains, instead of along the valleys, to collect data in the west-east direction and make this research possible."

Building and breaking

As the Indian tectonic plate moves from the south, the mantle, the thickest and strongest part of the plate, is dipping beneath the Tibetan plateau. The new analyses reveal that this process is causing small parts of the Indian plate to break off beneath two of the surface rifts, likely creating tears in the plate - similar to how a truck barreling through a narrow gap between two trees might chip off pieces of tree trunk. The location of such tears can be critical for understanding how far a major earthquake like Gorkha will spread.

"These transitions, these jumps between the faults, are so important and they're at a scale that we don't normally notice until after an earthquake has happened," Klemperer said.

An unusual aspect of Tibet involves the occurrence of very deep earthquakes, more than 40 miles below the surface. Using their seismic data, the researchers found associations between the plate tears and the occurrence of those deep quakes.

The research also explains why the strength of gravity varies in different parts of the collision zone. The co-authors hypothesized that after the small pieces dropped off of the Indian plate, softer material from underneath bubbled up, creating mass imbalances in the India-Tibet collision zone.

A natural laboratory

The India-Tibet region also provides insight into how parts of the eastern U.S. could have been formed through continental collisions about a billion years ago.

"The only way to understand what might have happened in eastern North America today is to come to Tibet," Klemperer said. "For geologists, this is the one big continental collision that is taking place on Earth today - it's this natural laboratory where we can study these processes."

Achieving herd immunity to COVID-19 is an impractical public health strategy, according to a new model developed by University of Georgia scientists. The study recently appeared in Proceedings of the National Academy of Sciences.

Controlling COVID-19 has presented public health policymakers with a conundrum:

How to prevent overwhelming their health care infrastructure, while avoiding major societal disruption? Debate has revolved around two proposed strategies. One school of thought aims for "suppression," eliminating transmission in communities through drastic social distancing measures, while another strategy is "mitigation," aiming to achieve herd immunity by permitting the infection of a sufficiently large proportion of the population while not exceeding health care capacity.

"The herd immunity concept is tantalizing because it spells the end of the threat of COVID-19," said Toby Brett, a postdoctoral associate at the Odum School of Ecology and the study's lead author. "However, because this approach aims to avoid disease elimination, it would need a constant adjustment of lockdown measures to ensure enough--but not too many--people are being infected at a particular point in time. Because of these challenges, the herd immunity strategy is actually more like attempting to walk a barely visible tightrope."

This study carried out by Brett and Pejman Rohani at the University of Georgia's Center for the Ecology of Infectious Diseases, investigates the suppression and mitigation approaches for controlling the spread of SARS-CoV-2, the virus that causes COVID-19.

While recent studies have explored the impacts of both suppression and mitigation strategies in several countries, Brett and Rohani sought to determine if and how countries could achieve herd immunity without overburdening the health care system, and to define the control efforts that would be required to do so.

They developed an age-stratified disease transmission model to simulate SARS-CoV-2 transmission in the United Kingdom, with spread controlled by the self-isolation of symptomatic individuals and various levels of social distancing.

Their simulations found that in the absence of any control measures, the U.K. would experience as many as 410,000 deaths related to COVID-19, with 350,000 of those being from individuals aged 60-plus.

They found that using the suppression strategy, far fewer fatalities were predicted: 62,000 among individuals aged 60-plus and 43,000 among individuals under 60.

If self-isolation engagement is high (defined as at least 70% reduction in transmission), suppression can be achieved in two months regardless of social distancing measures, and potentially sooner should school, work and social gathering places close.

When examining strategies that seek to build herd immunity through mitigation, their model found that if social distancing is maintained at a fixed level, hospital capacity would need to greatly increase to prevent the health care system from being overwhelmed. To instead achieve herd immunity given currently available hospital resources, the U.K. would need to adjust levels of social distancing in real time to ensure that the number of sick individuals is equal to, but not beyond, hospital capacity. If the virus spreads too quickly, hospitals will be overwhelmed, but if it spreads too slowly, the epidemic will be suppressed without achieving herd immunity.

Brett and Rohani further noted that much is unknown about the nature, duration and effectiveness of COVID-19 immunity, and that their model assumes perfect long-lasting immunity. They cautioned that if immunity is not perfect, and there is a significant chance of reinfection, achieving herd immunity through widespread exposure is very unlikely.

"We recognize there remains much for us to learn about COVID-19 transmission and immunity, but believe that such modeling can be invaluable in so-called 'situational analyses,'" said Rohani. "Models allow stakeholders to think through the consequences of alternative courses of action."

INDIANAPOLIS--Indiana University School of Medicine researchers are learning more about ways to prevent infections in women with obesity who have cesarean delivery. The multi-site study revealed using prophylactic negative pressure wound therapy (NPWT) does not appear to lower the risk of infection for this high-risk group.

"We now do more than 1.2 million C-sections a year in the United States, and infection has been one of the most common complications," said Methodius Tuuli, MD, MPH, MBA, vice chair of obstetrics and director of perinatal research at IU School of Medicine Department of Obstetrics and Gynecology. Tuuli is the study's principal investigator and lead author. "Infection can lead to longer hospital stays, an increase in health care cost and can also be particularly problematic for mothers to experience when trying to take care of a new baby."

The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) at the National Institutes of Health (NIH). The findings are published in a new article in the Journal of the American Medical Association (JAMA).

Pregnant women with obesity (having a body mass index over 30 prior to pregnancy) are more likely to have their babies through a C-section and are also more likely to develop an infection at the surgical site. NPWT involves using a special dressing on a surgical wound and using small tubing to connect the dressing to a low-pressure vacuum pump to create negative air pressure.

"We already know that when people have open wounds, whether it's after a C-section or diabetic wound or other surgical wound, using a NPWT pump can help in healing those wounds faster," Tuuli said. "It also makes management easier because you don't have to change the dressing every day."

Based on the same rationale, mobile NPWT pumps were approved by the Food and Drug Administration for application to closed wounds after incision closure at the time of surgery. This is the first large, randomized, multi-site clinical trial in the United States studying the effects of these pumps on the risk of infection in women with obesity who have C-sections. It is also the largest trial to date of prophylactic NPWT in any surgical procedure.

"The device was approved based on its ability to create negative pressure, but we wanted to see if it is effective and safe for reducing infection after C-section in obese women who are at high risk for wound infection," Tuuli said. "Previously, there have only been a few small studies, so we needed to do a large, multi-site trial to learn more."

More than 1,600 women participated in the study at six different hospitals across the U.S. The women were randomly assigned to one of two groups--802 received standard wound dressings, and 806 received NPWT after their wound was closed. The NPWT device was removed after an average of four days. In the NPWT group, 29 women developed infection at the surgical site (3.6%), compared to 27 in the standard wound dressing group (3.4%), a difference that was not statistically significant. Rates of major adverse events after surgery, including maternal death, blood infection, admission to an intensive care unit and the need for a hysterectomy after delivery, did not differ significantly between the two groups. However, women who received NPWT were more likely to have skin irritations, such as blistering, bleeding and redness (7.0% versus 0.6%).

The researchers concluded these findings do not support routine use of NPWT devices for obese women who deliver by C-section.

Because such low infection rates were achieved with the use of standard of care preventive measures, physicians should focus more efforts on using evidence-based interventions, like giving appropriate antibiotics before surgery, cleansing the skin with effective antiseptic, using good surgical techniques, and using sutures rather than staples when closing up the incision.

"There are evidence-based interventions that are less expensive, and we should put our energy into consistently implementing those interventions," Tuuli said. "This study shows that if we use these interventions consistently, using the NPWT device doesn't make a difference."

While in a three-dimensional world, all particles must be either fermions or bosons, it is known that in fewer dimensions, the existence of particles with intermediate quantum statistics, known as anyons, is possible. Such fascinating objects are strongly believed to exist as emerging quasiparticles in fractional quantum Hall systems, but despite great efforts, experimental evidence of anyons has remained very limited. Since quantum statistics is defined through the behavior of the phase of the wave function, when two identical particles are exchanged, early attempts of anyon detection have been based on interferometric measurements using Fabry-Perot interferometry or beamsplitter experiments.

So far, there have been many efforts to improve the experimental evidence of anyons by searching for ways to study the FQH effect and understand its underlying physics in highly controllable quantum systems such as cold atoms or photonic quantum simulators. There are studies that have shown that light-matter interactions can create and trap fractional quasiparticles in atomic gases or electronic systems and measure, through time-of-light imaging, signatures of fractional statistics carried by the total angular momentum of a fractional quantum Hall system.

In a recent study published in Physical Review Letters, ICFO researchers Tobias Grass, Niccolo Baldelli, and Utso Bhattacharya, led by ICREA Prof. at ICFO Maciej Lewenstein, and in collaboration with Bruno Julia-Díaz, from the University of Barcelona, describe a new approach towards anyon detection, which is a crucial element for increasing our knowledge of exotic quantum matter.

Contrary to earlier detection schemes, the study authored by the researchers opens up a new possibility which requires neither particle exchange nor interferometry. Instead, the authors suggest to trace the behavior of the anyons by binding impurity particles to them. Specifically, the average angular momentum of a single impurity is shown to take characteristic values that are possibly fractional. For a system of multiple impurities, the total angular momentum should then depend on how these effective single-impurity levels are filled. Strikingly, the value obtained by the authors corresponds neither to the filling of a Fermi sea nor to the condensation of a bosonic mode. Instead, the impurity angular momentum interpolates between these limiting cases, and the fractional statistical parameter of the anyons can be straightaway inferred from this interpolation.

Their detection scheme only requires density measurements and might be applicable to Abelian quantum Hall phases in electronic materials as well as in photonic or atomic quantum simulators. The authors discuss also possible generalizations towards non-Abelian anyons. Since the impurities realize a non-interacting gas of anyons, their work also poses the possibility of studying the intricate thermodynamics of anyonic systems.

Bottom Line:

Given the toll that the COVID-19 pandemic has taken on people's health and lives worldwide, it is crucial to be able to accurately predict patients' outcomes, including their chances of mortality from the disease. Using the largest clinical dataset to date, and a systematical machine learning framework, the research team at Mount Sinai identified an accurate and parsimonious prediction model of COVID-19 mortality.

This model was based on only three routinely collected clinical features, namely patient's age, minimum oxygen saturation over the course of their medical encounter, and type of patient encounter (inpatient vs outpatient and telehealth visits).

This model could yield an additional "vital sign" that is assessed regularly during a patient's hospital course, that can be integrated into the clinical care flow of a COVID-19 patient. Clinical teams could use results from the prediction model throughout COVID-19 patients' hospital courses to flag individuals at high risk of death so that they can promptly focus treatment and attention on such individuals to prevent their mortality.

Main Findings:

Using the largest development dataset yet (n=3841), and a systematic machine learning framework, we developed a COVID-19 mortality prediction model that showed high accuracy (AUC=0·91) when applied to test datasets of retrospective (n=961) and prospective (n=249) patients. This model was based on three clinical features: patient's age, minimum oxygen saturation over the course of their medical encounter, and type of patient encounter (inpatient vs outpatient and telehealth visits).

Motivation of the research:

The COVID-19 pandemic has affected millions of individuals and caused hundreds of thousands of deaths worldwide;

"Predicting mortality among patients with COVID-19 who present with a spectrum of complications is very difficult, hindering the prognostication and management of the disease," said Dr. Gaurav Pandey, Assistant Professor of Genetics and Genomic Sciences. "We aimed to develop an accurate prediction model of COVID-19 mortality using unbiased computational methods, and identify the clinical features most predictive of this outcome."

As wildfires rage across much of the American West, researchers at Stanford have used CAT scanners, the same instruments used in medicine to peer inside the human body, to understand the process of smoldering - the state of burning without flame that often leads to fire. They then folded this deeper understanding of burning into computer models to predict where wildfires might strike next. These models could help firefighters allocate precious resources, reduce the loss of property and help save lives, the researchers say.

"For wildfire risk assessment or if you're a firefighter, what you need is an accurate prediction about how fast the local fuel - the trees and plants nearby - will burn. We've analyzed this fuel in a new way that allows us to do just that," said Matthias Ihme, a professor of mechanical engineering and the senior author of the team's recent paper in the Proceedings of the Combustion Institute.

Seeing inside the material

To the untrained eye, smoldering may appear benign, but it's responsible for consuming more than half of the plant matter burned in wildfires. Smoldering logs can seethe for days and ignite anew, while glowing embers, carried aloft by hot updrafts, can transport wildfires to untouched areas in a flash.

"It's hard to get an accurate understanding of the smoldering process by looking at the exterior of a log," said Emeric Boigné, a graduate student in Ihme's lab, who developed a new analysis method using advanced X-ray Computed Tomography (XCT) to study the smoldering process. XCT is able to penetrate inside dense materials - just as it does with the human body - to provide three-dimensional images of wood structures less than a millimeter in scale as they smolder and eventually catch fire.

"Emeric recognized the potential of this unconventional use of the CT scanner," Ihme said. "You get inside the solid material and are able to measure the temperature of the surrounding flame in a new way."

The researchers envision collecting wood samples from around the country, perhaps even around the world, analyzing them using XCT and compiling a detailed database of various fuels. Boigné has traveled to a couple of locations already to collect wood samples and different flammable materials.

"Our goal is to establish a database for burn rates and conversions of different materials," Ihme said. "In theory, firefighters and others could send them to us from anywhere."

The power of parallel

To create a predictive fire model, Stanford graduate student Matt Bonanni combined the gathered information about the flammability of various materials with land contour data extracted from the sort of mapping databases that make GPS possible. The model also includes weather data, like relative humidity in the air and wind patterns.

Bonanni's simulations are on a forest-level scale, covering hundreds if not thousands of square miles. To simulate burning on that scale, he needed computer power - lots of it. So, he adopted an open-source framework called Tensor Flow that was originally developed for the processor-intensive task of machine learning. He is now working with Google Research to run these simulations on modern computing architecture, which allows them to operate much faster than ever before by completing many simulations simultaneously.

By multi-tasking, Bonanni's algorithm can run through countless permutations in the variables to predict how different combinations alter how a fire might spread and which are most likely to occur. Models that once took a whole day to run now can be done in near-real-time.

"Once your model reaches that speed, then you can actually use it as a live model of fire burning and make strategic decisions in the firefighting process," Bonanni said.

The model could one day be used to position firefighters where they'll be most effective in containing a wildfire. Or, conversely, to extract them when conditions turn too dangerous. Likewise, the models might assist in fire abatement efforts like prescribed burns, helping firefighters keep their intentional fires contained.

Next up, the team plans to further refine their model and grow their databases. For example, Boigné would like to use the technique to study "zombie fires" that burn uncontrolled in the peat beneath Arctic permafrost. Bonanni also hopes to make his models even more powerful.

"We've been working on improving the fidelity of the model, adding more complex physics into it," Bonanni says. "It'll only get better."

TORONTO, Sept. 22, 2020 - Although less than one per cent of all water in the world is freshwater, it is what we drink and use for agriculture. In other words, it's vital to human survival. York University researchers have just created a publicly available water quality database for close to 12,000 freshwater lakes globally - almost half of the world's freshwater supply - that will help scientists monitor and manage the health of these lakes.

The study, led by Faculty of Science Postdoctoral Fellow Alessandro Filazzola and Master's student Octavia Mahdiyan, collected data for lakes in 72 countries, from Antarctica to the United States and Canada. Hundreds of the lakes are in Ontario.

"The database can be used by scientists to answer questions about what lakes or regions may be faring worse than others, how water quality has changed over the years and which environmental stressors are most important in driving changes in water quality," says Filazzola.

The team included a host of graduate and undergraduate students working in the laboratory of Associate Professor Sapna Sharma in addition to a collaboration with Assistant Professor Derek Gray of Wilfrid Laurier University, Associate Professor Catherine O'Reilly of Illinois State University and York University Associate Professor Roberto Quinlan.

The researchers reviewed 3,322 studies from as far back as the 1950s along with online data repositories to collect data on chlorophyll levels, a commonly used marker to determine lake and ecosystem health. Chlorophyll is a predictor of the amount of vegetation and algae in lakes, known as primary production, including invasive species such as milfoil.

"Human activity, climate warming, agricultural, urban runoff and phosphorus from land use can all increase the level of chlorophyll in lakes. The primary production is most represented by the amount of chlorophyll in the lake, which has a cascading impact on the phytoplankton that eat the algae and the fish that eat the phytoplankton and the fish that eat those fish," says Filazzola. "If the chlorophyll is too low, it can have cascading negative effects on the entire ecosystem, while too much can cause an abundance of algae growth, which is not always good."

Watch videos: https://www.youtube.com/watch?v=-QIgtxfgo1A&feature=youtu.be
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Warming summer temperatures and increased solar radiation from decreased cloud cover in the northern hemisphere also contributes to an increase in chlorophyll, while more storm events caused by climate change contribute to degraded water quality, says Sharma. "Agricultural areas and urban watersheds are more associated with degraded water quality conditions because of the amount of nutrients input into these lakes."

The researchers also gathered data on phosphorous and nitrogen levels - often a predictor of chlorophyll - as well as lake characteristics, land use variables, and climate data for each lake. Freshwater lakes are particularly vulnerable to changes in nutrient levels, climate, land use and pollution.

"In addition to drinking water, freshwater is important for transportation, agriculture, and recreation, and provides habitats for more than 100,000 species of invertebrates, insects, animals and plants," says Sharma. "The database can be used to improve our understanding of how chlorophyll levels respond to global environmental change and it provides baseline comparisons for environmental managers responsible for maintaining water quality in lakes."

The researchers started looking only at Ontario lakes, but quickly expanded it globally as although there are thousands of lakes in Ontario a lot of the data is not as readily available as it is in other regions of the world.

"The creation of this database is a feat typically only accomplished by very large teams with millions of dollars, not by a single lab with a few small grants, which is why I am especially proud of this research," says Sharma.

PULLMAN, Wash. - Researchers at Washington State University have predicted how and where the Asian giant hornet, an invasive newcomer to the Pacific Northwest, popularly dubbed the "murder hornet," could spread and find ideal habitat, both in the United States and globally.

Sharing their discoveries in a newly published article in the Proceedings of the National Academy of Sciences, the team found that if the world's largest hornet gains a foothold in Washington state, it could spread down much of the west coast of the United States.

The Asian giant hornet could also find suitable habitat throughout the eastern seaboard and populous parts of Africa, Australia, Europe, and South America, if humans inadvertently transport it.

The team's predictions underline the importance of Washington state's efforts to stop the large insects before they spread.

"We found many suitable climates in the U.S. and around the globe," said lead author Gengping Zhu, a postdoctoral scholar at WSU's Department of Entomology.

Collaborating with Washington State Department of Agriculture scientist Chris Looney and WSU entomologists David Crowder and Javier Illan, Zhu examined more than 200 records from the hornet's native range in Japan, South Korea, and Taiwan, then used a set of ecological models incorporating climate data to predict likely global habitat across six continents.

"These predictions are scientific sleuthing," Illan said. "We're making an educated guess on how fast and far these insects can move, their rate of success in establishing a nest, and offering different scenarios, from least bad to worst. No one has done this before for this species."

A wide range of suitable habitats

Native to forested parts of Asia, the Asian giant hornet, Vespa mandarinia, is a significant threat to Western honey bees, which have no natural defense. In late summer and fall, hornet colonies attack beehives, destroying entire bee colonies to feed their brood and produce new queens.

Up to two inches long, the insect also deploys a potent sting, which is more dangerous than that of local bees and wasps.

Asian giant hornets are most likely to thrive in places with warm summers, mild winters, and high rainfall. Extreme heat is lethal, so their most suitable habitats are in regions with a maximum temperature of 102 degrees Fahrenheit.

Based on those factors, suitable habitat for the giant hornet exists along much of the U.S. west and east coasts, adjacent parts of Canada, much of Europe, northwestern and southeastern South America, central Africa, eastern Australia, and most parts of New Zealand.

Much of the interior of the U.S. is inhospitable to the hornet due to extremes of heat, cold, and low rainfall. This includes the eastern parts of Washington state and British Columbia, as well as California's Central Valley, all of which have major fruit and nut crops that rely on honey bee pollination.

Danger of accidental spread

Using data from a similar species, Vespa velutina, scientists predicted that without containment, Asian giant hornets could spread into southern Washington and Oregon, and north through British Columbia. Calculating that hornets could fly up to 68 miles per year, their worst-case scenario found that the insects could disperse throughout the western regions of Washington and Oregon in 20 years or less.

However, scientists cautioned that these predictions are an educated guess.

"The information that we want--how fast and far queens can fly, and when they fly--is all unknown," Illan said. "A lot of basic biology is unknown. So, we're using a surrogate."

"We know queens come out of their nest in the fall, mate, and fly--somewhere," Looney said. But nobody knows how far they fly, or if they fly repeatedly. We don't know if they set up nests in the spring near where they hibernated, or if they start flying again. These are some of the things that make predicting natural dispersal a challenge."

Nature alone cannot predict where the hornet may end up. Human activity plays a role in transporting invasive species around the globe.
While colonies can only be started by mated queens, and a USDA analysis found that accidental transport by humans is unlikely, Looney said that human-assisted spread could be a concern.

"It's easy for some species to get moved accidentally from one side of the country to the other, even if there's a large swathe of unacceptable habitat in between," he said.

"Preventing the establishment and spread of Asian giant hornet in western North America is critical for protecting bees and beekeepers," Crowder said. "Our study can inform strategies to monitor and eradicate these invaders before they become established."