Tech

Osaka, Japan - Photocatalysts that harness light energy and use it to split water into hydrogen and oxygen attract significant scholarly attention, owing to the appeal of hydrogen as a potential clean energy source. However, the optimization of photocatalyst candidate materials usually requires a considerable time investment. Now, researchers at Osaka University have demonstrated a link between easy-to-measure quantities and catalyst performance that could provide a rapid evaluation method.

The conversion of light energy to chemical energy using photocatalysts has been widely reported; however, the continual optimization of photocatalytic materials is critical for their successful application. The properties of photocatalysts, including their surface area, crystallinity, and various electronic features, affect their activity. These properties can be influenced by the techniques and specific conditions used to prepare them, thus leading to a broad range of materials that could be evaluated.

Experiment setup and test of every generated material is a time-consuming step in the development process that has yet to be accelerated--until now. In a report published in ACS Energy Letters, Osaka researchers have shown the relationship between time-resolved microwave conductivity (TRMC) measurements and the photocatalytic performance of semiconductor materials. TRMC is a facile process that allows photocatalysts to be evaluated in powder form, which leads to significantly higher throughput.

"We have been able to show that the oxygen evolution rate of a photocatalyst--which is a measure of activity--can be determined from the photoconductivity and the half-lifetime determined by TRMC," explains study lead author Hajime Suzuki. "Applying this relationship to materials makes evaluating their potential much more efficient."

The researchers used their findings to determine the optimum processing temperature for a material that had not been extensively studied, PbBiO2Cl, and were able to produce an analogue that had an apparent quantum efficiency of 3%--3 times higher than had been achieved in previous studies using higher processing temperatures.

"We hope that the principles of our findings can be widely applied to improve the efficiency and ease of screening materials, finding candidates, and choosing synthesis conditions," study corresponding author Akinori Saeki explains. "In terms of the broader picture, high throughput processes could accelerate the development of cleaner energy solutions."

Updated June 24, 2019 — NOTE: Out of an abundance of caution, The University of Toledo is working with the Ohio Department of Natural Resources to examine the terminology used in this study related to fracking wells. We value the research integrity of our University and hold ourselves to the highest standards as our researchers work to advance science. For more information, please see the release on the University of Toledo website.

A new study at The University of Toledo connects the proximity of fracking to higher household concentrations of radon gas, the second leading cause of lung cancer in the U.S.

Measuring and geocoding data from 118,421 homes across all 88 counties in Ohio between 2007 and 2014, scientists found that closer distance to the fracking wells is linked to higher indoor radon concentrations.

"The shorter the distance a home is from a fracking well, the higher the radon concentration. The larger the distance, the lower the radon concentration," Dr. Ashok Kumar, Distinguished University Professor and chair of the UToledo Department of Civil and Environmental Engineering, said.

The study also found the average radon concentrations among all tested homes across the state are higher than safe levels outlined by U.S. Environmental Protection Agency and World Health Organization standards. The average is 5.76 pCi/l, while the EPA threshold is 4.0 pCi/l. The postal code 43557 in the city of Stryker has the highest radon concentration at 141.85 pCi/l for this data set.

"We care about air quality," Dr. Yanqing Xu, assistant professor in the UToledo Department of Geography and Planning, said. "Our motivation is to save the lives of Ohioans. I hope this eye-opening research inspires families across the state to take action and have their homes tested for radon and, if needed, install mitigation systems to protect their loved ones."

The results of the study were recently published in the journal Frontiers in Public Health. The research is a collaboration between UToledo's Department of Civil and Environmental Engineering and Department of Geography and Planning. The radon data collection was supported by grants from the Ohio Department of Health and the U.S. Environmental Protection Agency.

Radon, which cannot be smelled or seen, begins as uranium found naturally in soil, water and rocks, but transforms into gas as it decays.

Fracking, or drilling the rock formation via hydraulic fracturing, stimulates the flow of natural gas. In Ohio, natural gas is available in deposits of the ancient Marcellus and Utica shales.

Most fracking wells are located in eastern Ohio, while Athens County has the highest number of fracking wells with 108. Fulton County is the only county with more than 20 fracking wells in western Ohio.

The researchers used data from the publicly accessible Ohio Radon Information System (ORIS), which the UToledo Department of Civil and Environmental Engineering started developing more than 25 years ago and maintains to improve public knowledge about indoor radon concentration. Licensed testers collect data each year in basements and first floors of homes in Ohio's 1,496 zip codes.

"You can find the average radon concentration in your zip code on the website," Kumar said.

Xu, a health geographer who previously studied obesity, installed a radon mitigation system after testing her home with a $10 kit.

"Shale is not in Toledo, but radon can get into homes because of uranium concentration in the soil, unrelated to fracking," Xu said. "My 2-year-old son likes to play in the basement, but radon concentration is higher in the basement. I did not hesitate even though the system cost around $1,000."

The data in the study are from self-reported devices and not distributed equally throughout Ohio.

PULLMAN, Wash. - Suppose you're at a nice restaurant celebrating your anniversary. When a customer at a nearby table complains that it's taking too long to get his meal, you and your spouse overhear the server's brusque response. Would the server's behavior prompt you to leave a smaller tip for your own meal?

When people witness poor customer service, studies indicate they want to seek revenge against the employee, even though they weren't directly affected.

New research out of Washington State University expands on the previous studies, looking at what happens when a manager steps in with an apology and how tips are affected.

A manager's intervention can help reduce witnesses' hostility toward the company or brand, reestablishing trust in the firm and preventing the loss of future business, the WSU study found. However, antagonism toward the individual employee remained. Bystanders still punished the employee through lower tips, according to the research.

Social media expands potential audience

The study has important takeaways, said Ismail Karabas, an assistant professor of marketing at Murray State University who worked on the research for his WSU doctoral dissertation.

"Employees should be aware that their audience is much larger than the customer they're focused on," Karabas said. "A negative response is likely to result in lower tips - not only from the disgruntled customer, but from others who witnessed the exchange."

In the era when a cell phone video can go viral on social media, it's critical for employees to understand the potential audience watching their interactions with customers, Karabas said.

"When I present this research, I often use the 2017 example of the passenger being dragged off the overbooked United Airlines flight," he said. "The bystanders aren't just the people who were physically present, but all the people who can watch the video online. With the growth in social media, our research becomes much more critical to companies and front-line employees."

Fairness important to customers' perceptions

Fairness is an important aspect of employee-customer interactions, said Jeff Joireman, professor of marketing at WSU's Carson College of Business. Customers' response to service often hinges on whether they think they or others were treated fairly, he said.

But the WSU research also showed that customers didn't differentiate between a neutral response to a complaint and a positive response. In the scenario where the customer complained about slow service, researchers tested several responses. Some servers apologized while promising to fix the problem, while others just said they'd fix it. Customers reacted well in both instances.

"You don't have to bend over backwards to appease customers - you only have to correct the problem," according to Joireman, who said that's an important finding to help prevent burnout in front-line employees.

CHAMPAIGN, Ill. -- If current climate and crop-improvement trends continue into the future, Midwestern corn growers who today rely on rainfall to water their crops will need to irrigate their fields, a new study finds. This could draw down aquifers, disrupt streams and rivers, and set up conflicts between agricultural and other human and ecological needs for water, scientists say.

The study, reported in the journal Ecosphere, calculated the extent to which hotter conditions expected by midcentury will draw more moisture out of corn plants, said University of Illinois plant biology professor Evan DeLucia, who led the study.

"As the atmosphere warms, it dries, and so the draw for water to go from plants to the atmosphere increases," DeLucia said. "The ability of the atmosphere to draw water from plants is determined by its 'vapor pressure deficit.'

"If you add to this the decades-old trend toward bigger, more productive corn plants, you see an overall increase in water use and water loss through plant leaves - without comparable increases in rainfall to counter the deficit," he said.

Today, average corn yields across the Midwest are roughly 170 bushels per acre, DeLucia said. This is up from about 120 bushels per acre in 1990.

"If this trend continues, the projected yield in 2050 would be 230-240 bushels per acre averaged across the Midwest," he said. "If you want more corn, then you have to have a bigger plant, and a bigger plant is going to use more water."

Precipitation is not expected to increase enough in the Midwest to compensate for the drying conditions of the warmer atmosphere, the researchers found.

"We are getting more intense storms in the spring and less rain in the late summer," DeLucia said. But the overall amount of precipitation is not expected to change much in the coming decades.

Even without increases in plant size and productivity, warming conditions alone will necessitate a much greater demand for water, the team found.

"We show that as vapor pressure deficit increases, maintaining current maize yields will require a large expansion of irrigation, greater than threefold, in areas currently supported by rain," the researchers wrote.

Some strategies can help counter the drying conditions, DeLucia said. The use of minimum tillage and mulches can reduce the rate of water loss from the soil. And breeding or genetically modifying plants to sequester more chlorophyll in their lower leaves and less in the top will allow photosynthesis to proceed more efficiently closer to the ground, where conditions are more humid. This will lessen the amount of moisture lost when plants open the pores in their leaves to take in carbon dioxide during photosynthesis. A research effort to do this is underway in the laboratory of U. of I. plant biology professor Donald Ort.

Researchers at the University of North Carolina at Chapel Hill Gillings School of Global Public Health and their colleagues at the University of Texas at Austin and the National Institutes of Health Vaccine Research Center have discovered an antibody that broadly inhibits multiple strains of pandemic norovirus, a major step forward in the development of an effective vaccine for the dreaded stomach virus.

The study, published in the June 18 issue of Immunity, describes for the first time the structure of the binding interaction between the virus and a human antibody that may work against many strains of the pandemic 'stomach bug.'

Research specialist Lisa Lindesmith and professor Ralph Baric, both of The Gillings School's department of epidemiology, are co-authors on the study.

Human noroviruses are the leading cause of acute gastroenteritis, inflammation of the stomach and intestines. It accounts for nearly one in five cases of diarrhea and vomiting, and is responsible for an estimated 200,000 deaths per year, mostly in infants, children and the elderly, according to the Centers for Disease Control and Prevention. Though there are more than 30 known genotypes of human norovirus, nearly 60% of outbreaks are caused by GII.4 genotype strains that have caused periodic human pandemics since 1996 through today, the authors wrote.

"In order to design an effective vaccine for norovirus, scientists needed to identify a neutralizing antibody that could work against many strains of the virus, as well as strains that will circulate in the future," said Baric. "This information can now be used to build better human vaccines."

The most important discovery of this study is a human antibody that can bind to a highly conserved region of the virus common among different strains of norovirus, potentially neutralizing all GII.4 strains of norovirus that exist in nature.

Highly conserved regions are parts of the virus that do not change. A human antibody that can target these highly conserved areas will provide broad protection for a prolonged period of time. With this knowledge, vaccine developers will have a better understanding of how, and how often, to reformulate the vaccine over time.

The technology, developed by co-author George Georgiou, was used to discover the key antibody in the study and the approach is applicable to a variety of highly variable bacteria and viruses.

"This study addresses a fundamental problem in norovirus disease development that could have wide-ranging impact on global health," says Lindesmith. "We've established an understanding of the virus and how it changes, how the body's immune response targets it and how we can use that information to make a better vaccine."

A new publication in the journal Frontiers in Marine Science tracks West Indian manatee movements through nearshore and offshore ship channels in the north-central Gulf of Mexico. The publication, "Linking Use of Ship Channels by West Indian Manatees (Trichechus manatus) to Seasonal Migration and Habitat Use", provides new fundamental knowledge on movement ecology of a large, protected marine species and important information to guide future conservation practices.

The work synthesizes 10 years of data collected by researchers at the Dauphin Island Sea Lab from satellite tracking, citizen-sourced sightings, and environmental attributes linked to manatee movements.

During migration, manatees have the potential to travel through a wide range of channel types and are exposed to a diversity of vessel types, including recreational boats, shrimp trawlers, barges, and large container ships. By understanding manatee movement patterns, we can better aid risk assessment for vessel collision and other shipping related activities for migratory marine species globally.

"More and more manatees are coming up from Florida during the summer time and using these ship channels as travel corridors. This means there's more of a chance they'll cross paths with a vessel of some kind, which makes them more vulnerable to boat strikes," said post-doctoral researcher Carl Cloyed. "By knowing when they are using these channels the most, we can suggest the best times for channel maintenance and give recreational and commercial boaters a better idea of when they may encounter a manatee during the year."

Manatees travel in both nearshore boat channels (i.e. rivers, canals, and estuaries) and open water fairways (i.e. Mobile Bay Ship Channel), but were found to use nearshore channels more frequently. Satellite-tracked manatees swam faster and moved more directly in all channel types, indicating these channels as migratory and travel corridors. In estuaries and rivers, manatees traveled north and south, consistent with movement among foraging habitats and other essential resources.

The approach used in this study can be applied to a wider range of species among locations to help predict when and how marine megafauna use ship channels and to evaluate risks associated with channel use.

WEST LAFAYETTE, Ind. -- If any factory worker could program low-cost robots, then more factories could actually use robotics to increase worker productivity.

This is because workers would be able to shift to taking on more varied and higher-level tasks, and factories could produce a greater variety of products.

That's the idea behind a prototype smartphone app Purdue University researchers have developed that allows a user to easily program any robot to perform a mundane activity, such as picking up parts from one area and delivering them to another.

The setup could also take care of household chores - no more plants dying because you forgot to water them.

Purdue researchers present their research on the embedded app, called VRa, on June 23 at DIS 2019 in San Diego. The platform is patented through the Purdue Research Foundation Office of Technology Commercialization, with plans to make it available for commercial use.

"Smaller companies can't afford software programmers or expensive mobile robots," said Karthik Ramani, Purdue's Donald W. Feddersen Professor of Mechanical Engineering. "We've made it to where they can do the programming themselves, dramatically bringing down the costs of building and programming mobile robots," he said.

Using augmented reality, the app allows the user to either walk out where the robot should go to perform its tasks, or draw out a workflow directly into real space. The app offers options for how those tasks can be performed, such as under a certain time limit, on repeat or after a machine has done its job.

After programming, the user drops the phone into a dock attached to the robot. While the phone needs to be familiar with the type of robot it's "becoming" to perform tasks, the dock can be wirelessly connected to the robot's basic controls and motor.

The phone is both the eyes and brain for the robot, controlling its navigation and tasks.

"As long as the phone is in the docking station, it is the robot," Ramani said. "Whatever you move about and do is what the robot will do."

To get the robot to execute a task that involves wirelessly interacting with another object or machine, the user simply scans the QR code of that object or machine while programming, effectively creating a network of so-called "Internet of Things." Once docked, the phone (as the robot) uses information from the QR code to work with the objects.

The researchers demonstrated this with robots watering a plant, vacuuming and transporting objects. The user can also monitor the robot remotely through the app and make it start or stop a task, such as to go charge its battery or begin a 3D-printing job. The app provides an option to automatically record video when the phone is docked, so that the user can play it back and evaluate a workflow.

Ramani's lab made it possible for the app to know how to navigate and interact with its environment according to what the user specifies through building upon so-called "simultaneous localization and mapping." These types of algorithms are also used in self-driving cars and drones.

A YouTube video is available at https://www.youtube.com/watch?v=_VCIHPDbcLk.

"We don't undervalue the human. Our goal is for everyone to be able to program robots, and for humans and robots to collaborate with each other," Ramani said.

Since creating the prototype, Ramani's lab has been testing it in real factory settings to evaluate user-driven applications. Ultimately, the app is a step toward creating future "smart" factories, powered by artificial intelligence and augmented reality, that complement and increase worker productivity rather than replacing them, Ramani said.

A new article published by researchers from University of Puget Sound and University of Washington reports that, based on analysis of public wastewater samples in at least one Western Washington population center, cannabis use both increased and substantially shifted from the illicit market since retail sales began in 2014.

Led by chemist Dan Burgard, the research team analyzed wastewater samples collected from 2013-2016 from two treatment plants that service a community of two hundred thousand in Western Washington.

"We set out to perform a wastewater-based analysis that explored the impact of newly legalized retail cannabis sales on its use, and to determine if this approach could estimate the size of the legal market place," says Burgard, who chairs the chemistry department at Puget Sound.

The researchers estimate that THC-COOH (the metabolite of psychoactive THC in cannabis created within the human body) found in wastewater has increased by 9% per quarter, on average, from December 2013 to December 2016. During this time, cannabis sales increased at nearly 70% per quarter, on average, for stores operating from August 2014 to December 2016.

"Given that wastewater represents a total population measure, these findings suggest that many established users switched very quickly from the illegal to the legal market," says Burgard. "This is the strongest statement possible regarding displacement of the illegal market."

Caleb Banta-Green, interim director and principal research scientist at University of Washington's Alcohol and Drug Abuse Institute, is a co-author of the article and was a key researcher on the project.

"This project was designed to aid the understanding of how the sales of adult recreational cannabis impact its total consumption within a population," says Banta-Green. "We believe this will be a valuable tool for local, state, national and international policy makers as they assess and consider Washington's recreational cannabis law."

In the past six years nine U.S. states (Colorado, Washington, Alaska, Oregon, Nevada, California, Maine, Massachusetts, Vermont, Michigan, and the District of Columbia), as well as the countries of Uruguay and recently Canada, have legalized the adult use of recreational cannabis.

"Existing measures, particularly surveys are subject to important biases and limitations, including potential changes in self-report as social norms change as well as very limited information on the amount of THC actually consumed," Banta-Green notes. "Wastewater based estimates help address these limitations."

The researchers note that their findings suggest that legalization is, in part, achieving one of its primary objectives which was to eliminate black market sales.

Funded in part by a grant from the National Institute on Drug Abuse, the research process included testing samples from 387 days spread over three years. The team utilized a new method that enables a complementary and potentially more timely and objective assessment of illicit drug consumption compared to existing measures.

Raw wastewater samples representing a full day are collected at a treatment plant and analyzed for drugs and their metabolites at extremely low concentrations (part per billion or part per trillion levels). These data can be used to track drug consumption trends, both legal and illegal, but not individual users. In some instances, the concentration of the metabolites can be used to "back calculate" to the actual number of doses of drug used in a particular area.

Tropical Cyclone Vayu was fading as it neared the coast of southwestern Pakistan and northwestern India. Dry air and wind shear were preventing development the development of thunderstorms, making the clouds on the storm's western side appear wispy in an image from NASA-NOAA's Suomi NPP satellite.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of the storm on June 17, 2019. The VIIRS image showed that dry air that moved into the storm on the western side had prevented further development of the thunderstorms that make up a tropical cyclone. Clouds on that side of Vayu appeared wispy and were precipitation free. Thicker clouds were visible on Vayu's eastern side where some had already spread over the coast of northwestern Indian near Naliya. Vayu is forecast to make landfall near Naliya later in the day.

On June 17 at 0300 UTC (June 16 at 11 p.m. EDT), the Joint Typhoon Warning Center issued the final warning on Vayu. At that time, Tropical Cyclone Vayu was located near 21.8 degrees north latitude and 66.8 degrees east longitude, approximately 180 nautical miles south of Karachi, Pakistan. Vayu was moving to the northeast and had maximum sustained winds near 35 knots (40 mph/65 kph) making it a minimal tropical storm.

In addition to dry air sapping the tropical cyclone's ability to create more thunderstorms, wind shear is pushing the remaining storms to the east of the center.

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.

Vayu is forecast to dissipate later in the day on June 17.

ITHACA, N.Y. - New research from Cornell University offers a new pathway for targeting pathogens in the fight against antibiotic resistant bacteria.

As antibiotic resistance rises, the search for new antibiotic strategies has become imperative. Researchers used the Cornell High Energy Synchotron Source (CHESS) to reveal an unexpected mechanism of activation and inactivation in the protein ribonucleotide reductase (RNR).

The findings were published in "Convergent Allostery in Ribonucleotide Reductase" in Nature Communications.

Understanding the "switch" that can turn RNR off provides a possible means to shut off the reproduction of harmful bacteria.

RNRs take ribonucleotides, the building blocks of RNA, and convert them to deoxyribonucleotides, the building blocks of DNA. In all organisms, the regulation of RNRs involves complex mechanisms. Without these mechanisms, DNA replication becomes error-prone, and dangerous mutations could occur.

"Without the RNR enzyme, DNA-based life as we know it could not exist," said first author William Thomas, a graduate student in chemistry and chemical biology. "If we understand the RNR 'off switch' well enough, we can take advantage of it by developing our own ways to toggle it with new antibiotic drug molecules."

This research reveals evolution in action, according to Nozomi Ando, assistant professor of chemistry and the paper's senior author. The lack of the normal regulatory "switch" mechanism may provide an evolutionary advantage for the bacteria they studied.

"Usually the increased chance of mutations is a problem for bacteria, but maybe under certain circumstances it's actually advantageous for an organism to mutate and possibly become resistant to an antibiotic or another stressful situation," she said.

RNRs are not easy proteins to work with or understand, and the researchers said characterizing them in the traditional way has been challenging.

"The combination of small-angle X-ray scattering using CHESS, crystallography, and cryo-electron microscopy is what made this study possible," Ando said.

ITHACA, N.Y. - Cornell University engineers have taken a step in understanding how iron in the soil may unlock naturally occurring phosphorus bound in organic matter, which can be used in fertilizer, so that one day farmers may be able to reduce the amount of artificial fertilizers applied to fields.

"This component of the phosphorus cycling process has been largely neglected," said senior author Ludmilla Aristilde, associate professor in biological and environmental engineering, "but now we're figuring out phosphorus recycling mechanisms by soil minerals that could benefit the environment."

"Phosphorus is a finite resource, but in agriculture we often apply it - and over-apply it - together with nitrogen on crops to amend soil health and boost crop growth," said co-author Annaleise Klein, a postdoctoral researcher in Aristilde's lab. "If we could understand the molecular mechanisms of these natural processes in the soil, and how those processes may be used by plants and bacteria, we can help the environment and thwart runoff from farms into streams and lakes - and possibly prevent algae blooms in nearby waters."

For farmers growing crops, phosphate fertilizer - derived from mining inorganic phosphate rock - is a dwindling resource. Once depleted, it is gone.

"The big picture is that phosphorus is a limited nutrient in the environment," said Klein. "Instead of mining rock phosphate for a farmer's fields - or a homeowner's lawn - now we can exploit the natural soil mechanism of phosphate release from organics and decrease our reliance on mined phosphorus."

Said Aristilde: "We are unraveling phosphorus cycling pathways that we didn't know about before. We don't want to keep adding more phosphorus. ... The less we mess with nature, the better."

The formation of air bubbles in a liquid appears very similar to its inverse process, the formation of liquid droplets from, say, a dripping water faucet. But the physics involved is actually quite different, and while those water droplets are uniform in their size and spacing, bubble formation is typically a much more random process.

Now, a study by researchers at MIT and Princeton University shows that under certain conditions, bubbles can also be coaxed to form spheres as perfectly matched as droplets.

The new findings could have implications for the development of microfluidic devices for biomedical research and for understanding the way natural gas interacts with petroleum in the tiny pore spaces of underground rock formations, the researchers say. The findings are published today in the journal PNAS, in a paper by MIT graduate Amir Pahlavan PhD '18, Professor Howard Stone of Princeton, MIT School of Engineering Professor of Teaching Innovation Gareth McKinley, and MIT Professor Ruben Juanes.

The key to producing uniformly sized and spaced bubbles lies in confining them to a narrow space, Juanes explains. When air or gas is released into a large container of liquid, the dispersal of bubbles is scattershot. When released into liquid that is confined in a relatively narrow tube, however, the gas will produce a stream of bubbles perfectly matched in size, and forming at even intervals. This uniform and predictable behavior, independent of specific starting conditions, is known as universality.

The process of formation of droplets or bubbles is very similar, beginning with an elongation of the flowing material (whether it's air or water), and eventually a thinning and pinch-off of the "neck" connecting the droplet or bubble to the flowing material. That pinch-off then allows the droplet or bubble to collapse into a spherical shape. Picture blowing soap bubbles: As you blow through the ring, a tube of soap film gradually extends outward in a long pouch before pinching off to form a round bubble that floats away.

"The process of a droplet dripping from a faucet is known to be universal," says Juanes, who has a joint appointment in the departments of Civil and Environmental Engineering and Earth, Atmospheric and Planetary Sciences. If the dripping liquid has a different viscosity or surface tension, or if the opening of the faucet is a different size, "it doesn't matter. You can find relationships that allow you to determine a master curve or a master behavior for describing that process," he says.

But when it comes to what is, in a sense, the opposite process to a dripping faucet -- the injection of air through an opening into a large tank of liquid such as a Jacuzzi tub -- the process is not universal. "So if you have irregularities in the orifice, or if the orifice is larger or smaller, or if you inject with some pulsation, all of that will lead to a different pinch-off of the bubbles," Juanes says.

The new experiments involved gas percolating onto viscous liquids such as oil. In an unconfined space, the sizes of the bubbles are unpredictable, but the situation changes when they bubble into liquid in a tube instead. Up to a certain point, the size and shape of the tube doesn't matter, nor do the characteristics of the orifice the gas comes through. Instead the bubbles, like the droplets from a faucet, are uniformly sized and spaced.

Pahlavan says, "Our work is really a tale of two surprising observations; the first surprising observation came around 15 years ago, when another group investigating formation of bubbles in large liquid tanks observed that the pinch-off process is nonuniversal" and depends on the details of the experimental setup. "The second surprise now comes in our work, which shows that confining the bubble inside a capillary tube makes the pinch-off insensitive to the details of the experiment and therefore universal."

This observation is "surprising," he says, because intuitively it might seem that bubbles able to move freely through the liquid would be less affected by their initial conditions than those that are hemmed in. But the opposite turned out to be true. It turns out that interactions between the tube and the forming bubble, as a line of contact between the air and the liquid advances along the inside of the tube, play an important role. This "effectively erases the memory of the system, of the details of the initial conditions, and therefore restores the universality to the pinch-off of a bubble," he says.

While such research may seem esoteric, its findings have potential applications in a variety of practical settings, Pahlavan says. "Controlled generation of drops and bubbles is very desirable in microfluidics, with many applications in mind. A few examples are inkjet printing, medical imaging, and making particulate materials."

The new understanding is also important for some natural processes. "In geophysical applications, we often see fluid flows in very tight and confined spaces," he says. These interactions between the fluids and the surrounding grains are often neglected in analyzing such processes. But the behavior of such geological systems is often determined by processes at the grain-scale, which means that the kind of microscale analysis done in this work could be helpful in understanding even such very large-scale situations.

The bubble formation in such geological formations can be a blessing or a curse, depending on the context, Juanes says, but either way it's important to understand. For carbon sequestration, for example, the hope is to pump carbon dioxide, separated out from power plant emissions, into deep formations to prevent the gas from getting out into the atmosphere. In this case, the formation of bubbles in tiny pore spaces in the rock is an advantage, because the bubbles tend to block the flow and keep the gas anchored in position, preventing it from leaking back out.

But for the same reason, bubble formation in a natural gas well can be a problem, because it can also block the flow, inhibiting the ability to extract the desired natural gas. "It can be immobilized in the pore space," he says. "It would take a much greater pressure to be able to move that bubble."

Scientists from the University of Massachusetts Amherst, Vanderbilt University and Clark University have shed new light on the genomic foundation of the polar bear's ecological adaption by pinpointing rapid changes in the bear's gene copy numbers in response to a diet shifting from vegetation to meat.

In a paper published Monday, June 17 in the Proceedings of the National Academy of Sciences and chosen for the cover of PNAS Vol. 116, issue 27, John G. Gibbons and Ph.D. student Shu Zhao of UMass Amherst, David C. Rinker of Vanderbilt and Natalya K. Specian of Clark discuss the first population-level study to characterize genome-wide patterns of copy number variation (CNV) in the polar bear and brown bear.

CNV refers to differences among individuals in the number of copies of a particular portion of the genome, and the study's results suggest this variation played an important role in the adaptation of polar bears to the Arctic.

"This research addresses a big-picture evolutionary question of how diet shapes the genome," explains Gibbons, assistant professor of food science.

Since the brown or grizzly bear (Ursus arctos) and polar bear (Ursus maritimus) diverged less than 500,000 years ago, the polar bear has evolved unique traits to adapt to the Arctic climate and ecology, such as a camouflaging coat of pigment-free fur. Previous population genomic studies of polar bears and brown bears analyzed single-nucleotide polymorphisms, or changes in a single base pair in a DNA sequence.

"CNVs were traditionally harder to detect so they weren't always analyzed," Gibbons says. "With recent advances in DNA sequencing technologies over the last 15 years or so, computational approaches to detect and quantify CNVs from genomic data have been developed. The polar bear data gave us a nice opportunity to fill in the gap."

Using available raw whole-genome DNA sequence data, the team of researchers compared differences in gene copy numbers among 17 polar bears, nine brown bears and two black bears. "Polar bears and brown bears are excellent models for exploring the impact of natural selection on CNV," the researchers write, "because they inhabit vastly different habitats yet are so recently diverged that they remain capable of producing fertile hybrid."

Gibbons says he and his colleagues hoped to see differences in gene copy numbers related to the bears' diet, and they did. Brown bears are omnivores, primarily consuming vegetation, while polar bears evolved quickly to a fully carnivorous diet, eating seals and other animals.

"This was a test case in understanding the effect of differences in diet on copy number variations," Gibbons says. "If we didn't see it here, we might not see it anywhere. It was pretty widespread and pretty convincing."

Gibbons points to two of the interesting findings. Of the genes annotated as olfactory receptors, 88 percent had lower copy numbers in polar bears, compared with brown bears and black bears. He explains, "First, there is less to smell in the Arctic. The polar bears mainly have to hone in on two things - seals and mates. They aren't looking for berries, grasses, herbs, roots and bulbs, like the brown bear."

Polar bears also were found to possess fewer copies of the gene AMY1B than brown bears. AMY1B encodes salivary amylase, the enzyme that jump-starts the digestion of starch when animals chew plant-based food. "Human populations with a high-starch diet have more copies of this gene in their genome than human populations with a lower-starch diet," Gibbons says. "We found the same thing with bears. If you think about their diets, it makes sense."

The new research concludes that analyzing copy number variants is an important tool when investigating evolutionary changes driven by natural selection.

"Evolution acts on different types of genetic variants to do the same thing," Gibbons says. "Now that we have the technology to detect CNVs, the consensus is that this type of mutation should be examined, along with the traditional methods for detecting parts of the genome that are shaped by natural selection."

Gibbons plans to build on the polar bear genomic research with an investigation of another species: Homo sapiens. "Our next step is to look at two different human populations to see if we see similar differences in copy number variants."

DURHAM, N.C. - Immunotherapies have transformed cancer care, but their successes have been limited for reasons that are both complex and perplexing.

In breast cancer especially, only a small number of patients are even eligible to undergo treatment with immunotherapies, and most see little benefit.

But in a pre-clinical study led by the Duke Cancer Institute, researchers outlined a potential way to improve those results by uncloaking breast cancer tumors to the body's immune system.

Publishing this month in the journal Nature Communications, the researchers identified an enzyme in cells involved in regulating the growth and spread of breast cancers. Testing in mice, they demonstrated a way to shut down the enzyme's activity to allow T-cells to mount an immune attack.

"We found that inhibition of the activity of this enzyme decreased the ability of macrophages in tumors to suppress an immune attack on cancer cells and indeed encouraged them to start producing chemicals that attract more cancer-killing T cells into the tumor," said Donald McDonnell, Ph.D., chair of Duke's Department of Pharmacology & Cancer Biology. "We can basically uncloak the tumor to the immune system."

McDonnell and colleagues, including lead author and collaborator Luigi Racioppi, M.D., Ph.D., reported that a kinase, or enzyme, called CaMKK2 is highly expressed in macrophages within human breast tumors. They performed a series of exploratory studies that revealed the molecule's potential utility as a therapeutic target for breast cancer. Working with colleagues at the University of North Carolina at Chapel Hill, they developed a new class of drugs that inhibited the growth of human breast tumors grown in mice.

"The use of this molecule suppressed tumor growth not only by increasing the accumulation of tumor-killing T cells, but also by reducing the tumor's capability to suppress T cell activity," McDonnell said. "It's solving two problems, like we couldn't get into the bar, and if we did, we couldn't get a drink. Now we can do both."

McDonnell said additional studies are ongoing, with the goal of acquiring data to launch a clinical trial in breast cancer patients within the next 18 months.

Language in Facebook posts may help identify conditions such as diabetes, anxiety, depression and psychosis in patients, according to a study from Penn Medicine and Stony Brook University researchers. It's believed that language in posts could be indicators of disease and, with patient consent, could be monitored just like physical symptoms. This study was published in PLOS ONE.

"This work is early, but our hope is that the insights gleaned from these posts could be used to better inform patients and providers about their health," said lead author Raina Merchant, MD, MS, the director of Penn Medicine's Center for Digital Health and an associate professor of Emergency Medicine. "As social media posts are often about someone's lifestyle choices and experiences or how they're feeling, this information could provide additional information about disease management and exacerbation."

Using an automated data collection technique, the researchers analyzed the entire Facebook post history of nearly 1,000 patients who agreed to have their electronic medical record data linked to their profiles. The researchers then built three models to analyze their predictive power for the patients: one model only analyzing the Facebook post language, another that used demographics such as age and sex, and the last that combined the two datasets.

Looking into 21 different conditions, researchers found that all 21were predictable from Facebook alone. In fact, 10 of the conditions were better predicted through the use Facebook data instead of demographic information.

Some of the Facebook data that was found to be more predictive than demographic data seemed intuitive. For example, "drink" and "bottle" were shown to be more predictive of alcohol abuse. However, others weren't as easy. For example, the people that most often mentioned religious language like "God" or "pray" in their posts were 15 times more likely to have diabetes than those who used these terms the least. Additionally, words expressing hostility -- like "dumb" and some expletives-- served as indicators of drug abuse and psychoses.

"Our digital language captures powerful aspects of our lives that are likely quite different from what is captured through traditional medical data," said the study's senior author Andrew Schwartz, PhD, a visiting assistant professor at Penn in Computer and Information Science, and an assistant professor of Computer Science at Stony Brook University. "Many studies have now shown a link between language patterns and specific disease, such as language predictive of depression or language that gives insights into whether someone is living with cancer. However, by looking across many medical conditions, we get a view of how conditions relate to each other, which can enable new applications of AI for medicine."

Last year, many members of this research team were able to show that analysis of Facebook posts could predict a diagnosis of depression as much as three months earlier than a diagnosis in the clinic. This work builds on that study and shows that there may be potential for developing an opt-in system for patients that could analyze their social media posts and provide extra information for clinicians to refine care delivery. Merchant said that it's tough to predict how widespread such a system would be, but it "could be valuable" for patients who use social media frequently.

"For instance, if someone is trying to lose weight and needs help understanding their food choices and exercise regimens, having a healthcare provider review their social media record might give them more insight into their usual patterns in order to help improve them," Merchant said.

Later this year, Merchant will conduct a large trial in which patients will be asked to directly share social media content with their health care provider. This will provide a look into whether managing this data and applying it is feasible, as well as how many patients would actually agree to their accounts being used to supplement active care.

"One challenge with this is that there is so much data and we, as providers, aren't trained to interpret it ourselves -- or make clinical decisions based on it," Merchant explained. "To address this, we will explore how to condense and summarize social media data."