Global pollution estimates reveal surprises, opportunity

Researchers' hybrid dataset includes satellite images, modeling and air samples

WASHINGTON UNIVERSITY IN ST. LOUIS

 

IMAGE: CALCULATED TRENDS IN GEOPHYSICAL PM2.5 VALUES FROM 1998-2018. WARM COLORS INDICATE POSITIVE TRENDS, COOL COLORS INDICATE NEGATIVE TRENDS AND THE OPACITY OF THE COLORS INDICATES THE STATISTICAL SIGNIFICANCE OF THE... view more 

CREDIT: MARTIN LAB

It is not unusual to come across headlines about pollution or global warming and find that they reach different conclusions depending upon the data source.

Researchers at Washington University in St. Louis used a harmonized approach, incorporating data from multiple satellites and ground monitors with computer modeling to compile a comprehensive, consistent map of pollution across the globe. Their data spans 1998-2018, providing a current picture of the state of the world's air quality that reveals some surprises, both for better and for worse.

The research was led by Melanie Hammer, a postdoctoral research fellow in the lab of Randall Martin, professor of energy, environmental and chemical engineering in the McKelvey School of Engineering.

Results of their study that looked at PM2.5 -- tiny particles that are able to make their way deep into a person's respiratory system -- were published June 3 in Environmental Science & Technology.

"Prior studies that look at long-term PM2.5 haven't used data as recent as we have," Hammer said. Older data can't capture the results of many programs aimed at curbing pollution -- even if they have been in effect for nearly a decade.

That turned out to be the case in China, where a significant drop in pollution in the recent past was the result of strategies begun in earnest around 2011. Other data sets don't capture the drop.

And in India -- another area of concern -- the story was not as positive. "It seems there's a bit of a plateau of PM2.5 levels," Hammer said. Though still, levels are not rising as steeply as other reports may suggest.

PM2.5 refers to the size of particles -- 2.5 microns. These tiny particles are created in nature, but also by human activities, including some manufacturing processes, car exhaust and the use of wood-burning cookstoves.

It's not easy to measure the amount of PM2.5 on the ground because there isn't any kind of comprehensive monitoring network covering the globe. North America and Europe have extensive monitoring systems, as does China. But, Martin said, "There are large gaps in ground-based monitoring. People can be living hundreds of kilometers away from monitors."

To develop a comprehensive pollution map, then, ground-based monitors are simply insufficient.

To capture a global snapshot, Martin's team started with satellite images of columns of atmosphere that spanned the ground to the edge of space. Using the established GEOS-Chem model, which simulates atmospheric composition, they could infer how much PM2.5 should be on the ground, at the bottom of any given column.

When comparing the predictions to actual levels measured by ground monitors, the agreement was striking. In fact, Martin said, "It's the best level of agreement found to date."

But the researchers still went a step further.

The agreement was great, but not perfect. So Hammer added the differences between the observed and predicted amounts of PM2.5 and expanded the ground-based predictions across the globe, filling in the massive gaps between monitors.

This extra step brought the observed and predicted levels of PM2.5 from 81% to 90% agreement.

Once they were able to take a good look at the most recent pollution levels around the world, the researchers saw some stark changes from previous trends. Particularly in China.

"We're used to seeing just large, increasing trends in pollution," Hammer said. But in China, "What we found, from 2011 to 2018, is that there actually is a particularly large negative trend."

Elsewhere in Asia, the picture wasn't as positive.

While pollution levels did not seem to be increasing in India, the country seems to be in a plateau phase. "The broad plateau of very high concentrations, to which a large population is exposed, is quite concerning," Martin said. "It affects the health of a billion people."

However, the takeaway from this research can be, on the balance, a hopeful one: It seems to show one possible way forward.

"The data Melanie's analysis reveals is a real success story for air quality controls," Martin said. "It shows they can be remarkably effective at reducing PM2.5." Although scientists have known these controls contain the potential to make an impact, he said, "The changes in China are very dramatic, larger than we have seen anywhere in the world over the observational record.

"It illustrates a real opportunity to improve air quality through effective controls."

Pollution, health around the world

In people already sick with illness such as asthma, PM2.5 can have immediate health consequences. Long-term, however, breathing in these particles carries consequences for everyone.

"PM2.5 is a major public health concern globally," said Melanie Hammer, postdoctoral researcher in the lab of Randall Martin in the McKelvey School of Engineering. "It's important to get accurate exposure estimates to estimate health impacts."

That's why organizations, including World Health Organization and Global Burden of Disease, use data from Martin's lab.

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Researchers discover critical new allergy pathway

Mouse study discovery points to potential new drug targets for treating asthma, hay fever, and other inflammatory disorders

JOHNS HOPKINS UNIVERSITY BLOOMBERG SCHOOL OF PUBLIC HEALTH

 

Researchers at Johns Hopkins Bloomberg School of Public Health have identified the sequence of molecular events by which tiny, tick-like creatures called house dust mites trigger asthma and allergic rhinitis.

The researchers, whose study was published online June 22 in Nature Immunology, found that allergy-triggering molecules from dust mites can interact with an immune protein called SAA1, which is better known as a sentinel against bacteria and other infectious agents. The researchers showed step-by-step how this interaction between mite-molecules and SAA1 triggers an allergic-type immune response in mice.

The findings reveal what may be a significant new pathway by which allergic and inflammatory disorders arise. They also suggest that blocking the pathway could potentially work as a preventive or treatment strategy against asthma and other allergic reactions.

"We think that the signaling interactions that occur immediately downstream of the mite-proteins' activation of SAA1 may be good targets for future drugs," says study senior author Marsha Wills-Karp, PhD, the Anna M. Baetjer Professor of Environmental Health and Chair of the Department of Environmental Health and Engineering at the Bloomberg School.

Asthma affects between 8 to 15 percent of people in the U.S., and is typically triggered by dust mites, tree and grass pollens, and other allergens. Researchers suspect that this inappropriate immune triggering happens when the immune system mistakes allergens--which are otherwise harmless--for pieces of bacteria or other infectious agents. However, the molecular mechanisms underlying this misidentification haven't been well understood.

In their study, Wills-Karp and her colleagues zeroed in on SAA1, an immune protein that is found, among other places, in the fluid that lines the airways and other mucosal surfaces. A member of the evolutionarily ancient "innate immune system" of mammals, SAA1 is thought to have evolved as a sentinel or early-responder molecule that, for example, recognizes and helps clear away certain types of bacteria and other infectious agents.

The researchers found that exposure to dust-mite proteins causes an asthma-like sensitization of the airways of the control group mice. In contrast, exposure to dust-mite proteins hardly had any effect in mice in which SAA1 was neutralized by antibodies, or in mice whose genes for SAA1 were knocked out. Further experiments confirmed that SAA1, when it is present, directly binds certain dust-mite allergens called fatty-acid binding proteins, which have structural similarities with proteins found in some bacteria and parasites. This allergen-SAA1 interaction releases SAA1 into its active form, wherein it activates a receptor called FPR2 on airway-lining cells. The airway cells then produce and secrete large quantities of interleukin-33, a protein known for its ability to stimulate allergic-type immune responses.

Confirming the likely relevance to humans, the researchers found evidence of increased production of SAA1 and FPR2 in nasal airway-lining cells from patients with chronic sinusitis--which is often linked to dust-mite allergens--compared to healthy controls.

"We think that different allergens take different routes to the activation of interleukin-33 and related allergic responses, and this SAA1-FPR2 route seems to be one that is taken by some dust-mite allergens," Wills-Karp says.

She and her colleagues now plan to investigate why some people develop allergic disorders in which this pathway is hyperactive, while most don't. They also plan to explore the possibility of blocking this pathway, perhaps at the SAA1-FPR2 interaction, as a way of treating asthma and other allergic disorders.

The researchers suspect that the newly described SAA1-FPR2 allergic pathway may be relevant not only in asthma and hay fever-type disorders but also in atopic dermatitis (eczema) and food allergies--possibly even in chronic inflammatory disorders such as rheumatoid arthritis and atherosclerosis.

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First author Ursula Smole, PhD, worked on the study while at the Bloomberg School.

"Serum amyloid A is a soluble pattern recognition receptor that drives type 2 immunity" was written by Ursula Smole, Naina Gour, Jordan Phelan, Gerhard Hofer, Cordula Köhler, Bernhard Kratzer, Peter Tauber, Xiao Xiao, Nu Yao, Jan Dvorak, Luis Caraballo, Leonardo Puerta, Sandra Rosskopf, Jamila Chakir, Ernst Malle, Andrew Lane, Winfried Pickl, Stephane Lajoie, and Marsha Wills-Karp.

Funding was provided by the National Institute of Allergy and Infectious Diseases (U19AI070235, R01 AI083315), the National Institutes of Health (R56AI118791, R01AI127644, R01AI132590), and the Austrian Science Fund (DK W1248, SFB F4609).

Common food additive causes adverse health effects in mice

UMass Amherst researchers find TiO2 nanoparticles produce inflammation in colon

UNIVERSITY OF MASSACHUSETTS AMHERST

 

IMAGE: HANG XIAO IS PROFESSOR AND CLYDESDALE SCHOLAR OF FOOD SCIENCE AT UMASS AMHERST. view more 

CREDIT: UMASS AMHERST

A common food additive, recently banned in France but allowed in the U.S. and many other countries, was found to significantly alter gut microbiota in mice, causing inflammation in the colon and changes in protein expression in the liver, according to research led by a University of Massachusetts Amherst food scientist.

"I think our results have a lot of implications in the food industry and on human health and nutrition," says lead author Hang Xiao, professor and Clydesdale Scholar of Food Science. "The study confirmed a strong linkage between foodborne titanium dioxide nanoparticles (TiO2 NPs) and adverse health effects."

Along with colleagues at UMass Amherst and in China, Xiao published the research in Small, a weekly, peer-reviewed, interdisciplinary journal that covers nanotechnology.

Gut microbiota, which refers to the diverse and complex community of microorganisms in the gut, plays a vital role in human health. An imbalance of gut microbiota has been associated with a range of health issues, including inflammatory bowel disease, obesity and cardiovascular disease.

Human exposure to foodborne TiO2 NPs comes primarily from a food additive known as E171, which is made up of different-size particles of TiO2, including one-third or more that are nanoscale. E171, which makes products look whiter and more opaque, is found in such food as desserts, candy, beverages and gum. E171 exposure is two to four times higher in U.S. children than in adults, Xiao points out that one study found.

Smaller than 100 nanometers, foodborne nanoscale particles may have unique physiological properties that cause concern. "The bigger particles won't be absorbed easily, but the smaller ones could get into the tissues and accumulate somewhere," Xiao says.

In their study, Xiao and his team fed either E171 or TiO2 NPs to two populations of mice as part of their daily diet. One population was fed a high-fat diet similar to that of many Americans, two-thirds of whom are obese or overweight; the other group of mice was fed a low-fat diet. The mice fed a high-fat diet eventually became obese, while the mice on the low-fat diet did not.

"In both the non-obese mice and obese mice, the gut microbiota was disturbed by both E171 and TiO2 NPs," Xiao says. "The nanosized particles caused more negative changes in both groups of mice." Moreover, the obese mice were more susceptible to the adverse effects of TiO2 NPs, causing more damage in obese mice than in non-obese ones.

The researchers found TiO2 NPs decreased cecal levels of short-chain fatty acids, which are essential for colon health, and increased pro-inflammatory immune cells and cytokines in the colon, indicating an inflammatory state.

To evaluate the direct health impact of gut microbiota disrupted by TiO2 NP, Xiao and colleagues conducted a fecal transplant study. They gave mice antibiotics to clear out their original gut microbiota and then transplanted fecal bacteria from the TiO2 NP-treated mice to the antibiotic-treated mice. "The results support our hypothesis that including TiO2 NPs in the diet disrupts the homeostasis of the gut microbiota," Xiao says, "which in turn leads to colonic inflammation in the mice."

The study also measured levels of TiO2 in human stool samples, finding a wide range. Xiao says further research is needed to determine the health effects of long-term - such as life-long and multigenerational - exposure to TiO2 NPs.

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Airborne chemicals could become less hazardous, thanks to a missing math formula

Discovery of how to measure surface viscosity of liquids could give machines more precise control over droplets

PURDUE UNIVERSITY

 

IMAGE: PURDUE RESEARCHERS HAVE FIGURED OUT A WAY TO CALCULATE SURFACE VISCOSITY JUST BY LOOKING AT A STRETCHED DROPLET AS IT STARTS TO BREAK. view more 

CREDIT: PURDUE UNIVERSITY IMAGES/BRAYDEN WAGONER AND OSMAN BASARAN

WEST LAFAYETTE, Ind. -- Drones and other aircraft effectively spray pesticides over miles of crops, but the method also can pollute the environment if wind carries the mist off-target.

One of the problems is that tiny droplets are hard for aerial crop sprayers, inkjet printers and a wide range of other machines to control. Purdue University engineers are the first to come up with the math formula that was missing to measure a key property of these droplets.

"There are many properties that affect how a droplet forms. One of those important properties is surface viscosity, which people have had a heck of a time trying to measure because they just didn't have the tools to do it," said Osman Basaran, Purdue's Burton and Kathryn Gedge Professor of Chemical Engineering.

Pesticides and other chemicals contain additives called surfactants. These surfactant molecules resist each other at a liquid's surface, giving rise to a sticky force called surface viscosity that can make the droplet smaller. The higher the surface viscosity, the more compact a droplet's shape.

Basaran and his students have figured out a way to calculate surface viscosity just by looking at how a droplet stretches. A picture taken of the stretched droplet as it starts to break gives the values to put into a simple math formula that provides the surface viscosity measurement.

The formula is described in a paper published in the journal Physical Review Letters. The discovery ends a decades-long race by researchers around the world to make surface viscosity measurable. Other co-authors on this paper include Hansol Wee, Brayden Wagoner and Pritish Kamat.

Not being able to measure exactly how much surface viscosity affects drop formation has put limits on making machines safer and more precise, said Basaran, who directs a center that works to resolve the science behind problems in manufacturing machinery.

Solutions provided by the center, called the Purdue Process Safety and Assurance Center, directly help partners in industries such as agriculture, health care and energy.

A better understanding of droplets and how to control them affects all those industries. Like crop spraying, inkjet printing in a factory produces tiny droplets that can get into the air and cause breathing problems.

More precise control of a liquid-like substance also could enhance a machine's performance, such as giving a 3D printer the ability to produce more reliable or detailed objects.

"A material with too high or too low surface viscosity can lead to bad outcomes in the manufacturing process. Knowing those measurements allows you to use different chemistries to make a material that doesn't lead to a surface viscosity that's going to result in a bad outcome," Basaran said.

Next, Basaran's team plans to incorporate this math formula into experiments for recommending new machine designs. The formula could also become a commercial instrument in the future, such as a smartphone app.

"This discovery opens up a lot of avenues for basic research that just weren't possible before," Basaran said.

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This research received no external funding.

ABSTRACT

Effects of surface viscosity on breakup of viscous threads

Hansol Wee, Brayden W. Wagoner, Pritish M. Kamat, and Osman A. Basaran,

Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, USA

DOI: 10.1103/PhysRevLett.124.204501

In addition to surface tension lowering and Marangoni stresses, surfactants also induce surface rheological effects when they deform against themselves at fluid interfaces. Because surface viscosities are functions of surfactant concentration, surface rheological stresses can compete with capillary, Marangoni, and bulk stresses in surfactant-laden free surface flows with breakup. To elucidate the effects of surface rheology, we examine the breakup of a Stokes thread covered with a monolayer of insoluble surfactant when either surfactants are convected away from the space-time singularity or diffusion is dominant. Surprisingly, in both limits, surface rheological effects always enter the dominant balance of forces and alter the thread's thinning rate. Moreover, if surfactants are convected away from the singularity, we provide an analytical expression for thinning rate that explicitly depends on surface rheological parameters, providing a simple route for measuring surface viscosity.

Undergrad-led study suggests light environment modifications could maximize productivity

CARL R. WOESE INSTITUTE FOR GENOMIC BIOLOGY, UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN

 

IMAGE: MAIZE (LEFT) AND MISCANTHUS (RIGHT) view more 

CREDIT: WEST PROJECT/UNIVERSITY OF ILLINOIS

CHAMPAIGN, Ill. -- The crops we grow in the field often form dense canopies with many overlapping leaves, such that young "sun leaves" at the top of the canopy are exposed to full sunlight with older "shade leaves" at the bottom. In order to maximize photosynthesis, resource-use efficiency, and yield, sun leaves typically maximize photosynthetic efficiency at high light, while shade leaves maximize efficiency at low light.

"However, in some of our most important crops, a maladaptation causes a loss of photosynthetic efficiency in leaves at the bottom of the canopy, which limits the plants' ability to photosynthesize and produce yields," said Charles Pignon, a former postdoctoral researcher at the University of Illinois. "In order to address this problem, it's important to know whether this is caused by leaves being older or exposed to a different light environment at the bottom of the canopy."

This question was answered in a recent study published in Frontiers in Plant Science, where researchers from the University of Illinois and the University of Oxford worked with maize and the bioenergy crop Miscanthus to find that the decline in the efficiency of leaves at the bottom of the canopy was not due to their age but to their altered light environment.

This work was conducted through the Illinois Summer Fellows (ISF) program. Launched in 2018, ISF allows undergraduate students to conduct plant science research alongside highly skilled scientists at Illinois. 2018 Fellows Robert Collison and Emma Raven worked with Pignon and Stephen Long, the Stanley O. Ikenberry Chair Professor of Plant Biology and Crop Sciences at Illinois, to confirm and better understand results from previous studies for Water Efficient Sorghum Technologies (WEST), a research project that aimed to develop bioenergy crops that produce more biomass with less water.

Photosynthesis is the natural process that plants use to convert sunlight into energy. Plants usually fall under the two main types of photosynthesis -- C3 and C4. The difference between these types is that C4 plants have a mechanism that concentrates carbon dioxide inside their leaves, allowing them to photosynthesize more efficiently. However, most plants, trees, and crops operate using the less efficient C3 photosynthesis.

Both sun and shade leaves contribute to photosynthetic carbon assimilation, producing the sugars that feed the plant and fuel yield. Therefore, lower canopy photosynthesis is an important process that affects the yield of the whole plant, with an estimated 50 percent of total canopy carbon gain contributed by shade leaves.

Previous studies of C3 plants have shown that shaded leaves are typically more efficient than sun leaves at low light intensities, meaning shaded leaves adapt to their low light environment. However, a previous study by Pignon and Long showed that this is not the case for all plants. The canopies of maize and Miscanthus, C4 crops that usually photosynthesize more efficiently than C3 crops, had shade leaves that were less photosynthetically efficient, suggesting a maladaptation in these important crops.

"Shade leaves receive very little light, so they usually become very efficient with low light use," said Pignon, now a plant physiologist at Benson Hill in St. Louis. "Essentially, they make the most of what little light they do receive. However, in the C4 crops we studied, shade leaves in these crops not only receive very little light, but they also use it less efficiently. It's a very costly maladaptation in crops that are otherwise highly productive -- hence our calling it an Achilles' heel."

With six to eight layers of leaves in our modern maize crop stands, most leaves are shaded and can account for half of the plant's growth during the critical phase of grain filling.

"In the previous study, researchers estimated that this maladaptation was causing a loss of 10 percent in potential canopy photosynthesis gain," said Raven, who recently graduated from Oxford with plans to pursue her doctorate. "There are essentially two potential reasons: the age of the leaves or the light conditions, so we investigated which factor was causing this inefficiency."

Collison and Raven, co-first authors of this newly published paper, collected data and analyzed the maximum quantum yield of photosynthesis -- the maximum efficiency with which light is used to assimilate carbon -- in leaves of the same chronological age but different light environments to discover the crops' Achilles' heel. This was achieved by comparing leaves of the same age in the center of plots of these species versus those on the sunlight southern edge of these plots. From this, they showed that the poor photosynthetic efficiency of these crops' lower leaves is caused by altered light conditions and not age.

"Maize and Miscanthus are both closely related to sugarcane and sorghum, so other C4 crops could potentially have this loss in photosynthetic efficiency caused by the light environment," explained Collison, who has also graduated from Oxford and may pursue graduate studies. "By finding the cause of this loss in efficiency, we can begin to look at potential solutions to this problem, modifying plants to improve their productivity."

Illinois Summer Fellows Program

The ISF program has cultivated an environment where the Fellows have the independence needed to develop as scientists while knowing that they have the support and encouragement of their supervisors. Fellows are paired with a scientist supervisor to assist them with a specific element of a project aimed to increase crops' photosynthetic and/or water-use efficiency. The program aims to provide a rewarding experience that helps students develop as scientists, and ultimately, to consider pursuing careers in plant biology.

"The opportunity to travel to another country and conduct meaningful research in a real-world field environment alongside mentors in their field is invaluable," said Long, who launched and directs the ISF program at the Carl R. Woese Institute for Genomic Biology. "At the end of their time at Illinois, our Fellows have expressed that this experience allowed them to contribute to the world and take back valuable skills they can apply in their future endeavors as innovators in the field of agriculture and beyond."

Collison reflects on his time at Illinois as an experience that not many students, especially so early in their career, get to take part in. "The chance to do any research so early in your career as a scientist is really exciting," he said. "Everyone we met-- including our supervisors and other scientists -- was always willing to help us."

Raven also shared her insights on the value of doing research at Illinois and what differences there may be in other academic or work settings. "When you are attending lectures or practical classes, you never quite get that feeling of true ownership of your own projects because you just follow whatever your professor tells you to do," Raven said. "But having ownership of this paper at Illinois is gratifying. It is also exciting to be a part of something that is bigger than us and will ultimately help farmers in other countries to grow food more sustainably."

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The ISF program is supported by Oxford University in England and the Realizing Increased Photosynthetic Efficiency (RIPE), an international research project led by Illinois that is engineering crops to be more productive by improving photosynthesis. It is supported by the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).

For mor

Bizarre saber-tooth predator from South America was no saber-tooth cat

UNIVERSITY OF BRISTOL

 

IMAGE: SKULLS AND LIFE RECONSTRUCTIONS OF THE MARSUPIAL SABER-TOOTH THYLACOSMILUS ATROX (LEFT) AND THE SABER-TOOTH CAT SMILODON FATALIS (RIGHT). view more 

CREDIT: STEPHAN LAUTENSCHLAGER

A new study led by researchers from the University of Bristol has shown that not all saber-tooths were fearsome predators.

Saber-tooth cats, such as the North American species Smilodon fatalis, are among the most iconic fossil animals with a reputation for being fierce predators. However, saber-tooths came in all shapes and sizes and nearly a hundred different saber-tooths are known to science so far.

Thylacosmilus atrox (which means 'terrible pouched knife') is a well-known animal that lived around five million years ago in Argentina.

A jaguar-sized marsupial, it is popularly known as the 'marsupial saber-tooth', compared with the sabertoothed cats elsewhere in the world, and it is often presented as a classic case of convergent evolution--where animals appear similar in form despite having very different evolutionary relationships (such as marsupial flying possums and placental flying squirrels - both of course being gliders rather than true fliers).

Thylacosmilus had huge, ever-growing canines, leading people to speculate that it was an even more vicious predator than the placental carnivores it superficially resembled such as Smilodon.

But was it really a fierce predator like the extinct placental saber-toothed cats, which seem to have been much like modern cats but with a different mode of killing their prey?

An international team of researchers, led by Professor Christine Janis from Bristol's School of Earth Sciences, have performed a series of studies on the skull and teeth of this animal and have come to a different conclusion. Their findings are published in the journal PeerJ.

Professor Janis said: "The title of this paper, 'An Eye for a Tooth', sums up how we think this animal has been perceived.

"It has impressive canines, for sure: but if you look at the whole picture of its anatomy, lots of things simply don't add up. For example, it just about lacks incisors, which big cats today use to get meat off the bone, and its lower jaws were not fused together.

"In addition, the canines of Thylacosmilus were different from the teeth of other saber-toothed mammals, being triangular in shape like a claw rather than flat like a blade."

A statistical study, comparing aspects of the skull and teeth of Thylacosmilus with both present-day big cats and a diversity of extinct saber-toothed cats, confirmed suspicions about the differences from its placental supposed counterparts.

Co-author Borja Figueirido of the University of Málaga (Spain) added: "The skull superficially looks rather like that of a saber-toothed placental.

"But if you actually quantify things, it becomes clear that Thylacosmilus' skull was different in many details from any known carnivorous mammal, past or present."

Detailed biomechanical studies comparing the skulls of Thylacosmilus and Smilodon, simulating performance under different conditions, were also revealing.

Stephan Lautenschlager from the University of Birmingham, the contributing author on the paper who performed these analyses, said: "Previous studies by other researchers have shown Thylacosmilus to have had a weaker bite than Smilodon.

"But what we can show is there was probably a difference in behaviour between the two species: Thylacosmilus' skull and canines are weaker in a stabbing action than those of Smilodon, but are stronger in a 'pull-back' type of action. This suggests that Thylacosmilus was not using its canines to kill with, but perhaps instead to open carcasses."

Finally, the other teeth of Thylacosmilus also pose problems for the interpretation of this animal as a cat-like predator, whether saber-toothed or not. Besides the puzzling lack of incisors, the molars are small, and did not wear down along the sides as seen in an animal feeding on meat.

Larisa DeSantis from Vanderbilt University (USA), who conducted a detailed dental study, added: "The molars tend to wear flat from the top, rather like you see in a bone crusher.

"But if you examine the detailed microwear on tooth surfaces, it's clear that it was eating soft food. Its wear is most similar to that of cheetahs which eat from fresh carcasses and suggests an even softer diet than fed to captive lions.

"Thylacosmilus was not a bone-crusher and may have instead specialised on internal organs."

Professor Janis said: "It's a bit of a mystery as to what this animal was actually doing but it's clear that it wasn't just a marsupial version of a saber-toothed cat like Smilodon.

"In addition to the differences in the skull and the teeth, it was also short-legged and stiff-backed, and lacked retractile claws, so it would have had difficulties in pursuing its prey, pouncing on it and holding on to it. I suspect it was some sort of specialised scavenger.

"It may have employed those canines to open carcasses and perhaps also used a big tongue to help extract the innards: other mammals that have lost the incisors, like walruses and anteaters, also have big tongues that they use in feeding."

When Thylacosmilus lived on the plains of Argentina five million years ago, it would have inhabited a very different type of ecosystem to any modern one. Then the big predators were huge flightless birds, the "terror birds" or phorusrachiformes, now all extinct. Life in the past may have been very different to the present day.

Borja Figueirido added: "In Africa today it's the mammals who are the killers and the big birds, like vultures, are the scavengers. But perhaps five million years ago in Argentina it was the other way around, and it was the mammals who were the scavengers."

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Tel Aviv University researchers destroy cancer cells with ultrasound treatment

Technique combines ultrasound application and tumor-targeted microbubbles that attach to cancer cells and explode

AMERICAN FRIENDS OF TEL AVIV UNIVERSITY

An international research team led by Dr. Tali Ilovitsh of the Biomedical Engineering Department at Tel Aviv University developed a noninvasive technology platform for gene delivery into breast cancer cells. The technique combines ultrasound with tumor-targeted microbubbles. Once the ultrasound is activated, the microbubbles explode like smart and targeted warheads, creating holes in cancer cells' membranes, enabling gene delivery. Conducted over two years, the research was published on June 9 in the journal Proceedings of the National Academy of Sciences (PNAS).

Dr. Ilovitsh developed this breakthrough technology during her post-doctorate research at the lab of Prof. Katherine Ferrara at Stanford University. The technique utilizes low frequency ultrasound (250 kHz) to detonate microscopic tumor-targeted bubbles. In vivo, cell destruction reached 80% of tumor cells.

"Microbubbles are microscopic bubbles filled with gas, with a diameter as small as one tenth of a blood vessel," Dr. Ilovitsh explains. "At certain frequencies and pressures, sound waves cause the microbubbles to act like balloons: they expand and contract periodically. This process increases the transfer of substances from the blood vessels into the surrounding tissue. We discovered that using lower frequencies than those applied previously, microbubbles can significantly expand, until they explode violently. We realized that this discovery could be used as a platform for cancer treatment and started to inject microbubbles into tumors directly."

Dr. Ilovitsh and the rest of the team used tumor-targeted microbubbles that were attached to tumor cells' membranes at the moment of the explosion, and injected them directly into tumors in a mouse model. "About 80% of tumor cells were destroyed in the explosion, which was positive on its own," says Dr. Ilovitsh. "The targeted treatment, which is safe and cost-effective, was able to destroy most of the tumor. However, it is not enough. In order to prevent the remaining cancer cells to spread, we needed to destroy all of the tumor cells. That is why we injected an immunotherapy gene alongside the microbubbles, which acts as a Trojan horse, and signaled the immune system to attack the cancer cell."

On its own, the gene cannot enter into the cancer cells. However, this gene aimed to enhance the immune system was co-injected together with the microbubbles. Membrane pores were formed in the remaining 20% of the cancer cells that survived the initial explosion, allowing the entry of the gene into the cells. This triggered an immune response that destroyed the cancer cell.

"The majority of cancer cells were destroyed by the explosion, and the remaining cells consumed the immunotherapy gene through the holes that were created in their membranes," Dr. Ilovitsh explains. "The gene caused the cells to produce a substance that triggered the immune system to attack the cancer cell. In fact, our mice had tumors on both sides of their bodies. Despite the fact that we conducted the treatment only on one side, the immune system attacked the distant side as well."

Dr. Ilovitsh says that in the future she intends to attempt using this technology as a noninvasive treatment for brain-related diseases such as brain tumors and other neurodegenerative conditions such as Alzheimer's and Parkinson's diseases. "The blood-brain barrier does not allow for medications to penetrate through, but microbubbles can temporary open the barrier, enabling the arrival of the treatment to the target area without the need for an invasive surgical intervention."

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American Friends of Tel Aviv University supports Israel's most influential, comprehensive and sought-after center of higher learning, Tel Aviv University (TAU). TAU is recognized and celebrated internationally for creating an innovative, entrepreneurial culture on campus that generates inventions, startups and economic development in Israel. TAU is ranked ninth in the world, and first in Israel, for producing start-up founders of billion-dollar companies, an achievement that surpassed several Ivy League universities. To date, 2,500 US patents have been filed by Tel Aviv University researchers -- ranking TAU #1 in Israel, #10 outside of the US and #66 in the world.

New process could safeguard water quality, environment and health

Pioneering single process can remove pollutants from waste water

SWANSEA UNIVERSITY

 

IMAGE: SAMPLES BEING PLACED INTO A CENTRIFUGE TO SEPARATE SAMPLE COMPONENTS. view more 

CREDIT: SWANSEA UNIVERSITY

A research team at Swansea University have developed a new method for fast removal and detection of wastewater pollutants that come from everyday pharmaceuticals like paracetamol, ibuprofen and aspirin, which could help minimise their impact on the environment.

The all-female team of (bio)chemists from the Medical School, in collaboration with international company, Biotage, have published the research in Analytical Science Advances. The research outlines how they successfully developed a single process for separating and quantifying a wide range of different pharmaceuticals and chemicals from personal care products found in everyone's bathrooms that can end up in wastewater sludge and blood plasma. The new method will speed up our understanding of which pollutants may be released and could help reduce the negative effects they have on the wider environment.

First author Dr Rachel Townsend said: "Many people don't really think about what happens to these drugs once they've taken them. Like any foodstuff, once a drug has been taken, it is excreted from the body and ends up in a wastewater treatment plant.

"It was thought that pharmaceuticals were degraded during the treatment process, but research has shown this isn't the case. And of course this becomes a problem as the treated wastewater is released into water courses such as rivers and streams, while 80% of treated sludge is also recycled back onto agricultural land as fertiliser and potentially onto future food crops."

There have been global reports of the adverse effects of pharmaceuticals on the animal kingdom. Diclofenac, for example, a non-steroidal anti-inflammatory has caused multiple species of vulture in Asia to become critically endangered, while the Indian long-billed vulture and red-headed vulture populations have decreased by 97-99%. The female contraceptive pill has caused the feminisation of male fish, which has caused populations to decrease rapidly over 2 years. There are also concerns that that sludge used in agriculture could impact on human health too.

The team have pioneered one process that uses a sample preparation method, called QuEChERS, with mass spectrometric detection. Using this process, they were able to detect, extract and quantify a range of pharmaceutical compounds and personal care products from a variety of sources, such as wastewater sludge, where previously multiple extraction methods were needed, making it more efficient in time and resources needed.

The researchers could then get a clearer picture of the factors controlling how antimicrobial resistance develops and spreads in the community, and this knowledge has the potential to help safeguard water quality, the environment and health.

The results will now help to inform the Chemical Investigation Programme, which is a British research initiative that contributes to the European Union Directive for environmental management. With enough research and data, changes can be made to the wastewater treatment process to ensure these everyday pollutants are degraded or removed with the hope of preventing any further impact on the wider environment and ensuring human health remains unaffected.

Co-author, Dr Claire Desbrow from Biotage said: "The newly developed method fits perfectly with our portfolio of sample preparation products. Being able to clean up complex human, food or environmental samples fast and efficiently will be of benefit to not only researchers, but also to industrial, environmental and regulatory laboratories across the globe."

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Unorthodox desalination method could transform global water management

Columbia engineers apply their pioneering technique to attain energy-efficient zero-liquid discharge--the last frontier of desalination--of ultrahigh salinity brines

COLUMBIA UNIVERSITY SCHOOL OF ENGINEERING AND APPLIED SCIENCE

IMAGE: ILLUSTRATION OF THE TSSE (TEMPERATURE SWING SOLVENT EXTRACTION) PROCESS, A PIONEERING DESALINATION APPROACH FOR HYPERSALINE BRINES THAT COULD TRANSFORM GLOBAL WATER MANAGEMENT. view more 

CREDIT: CHANHEE BOO/COLUMBIA ENGINEERING

New York, NY--June 25, 2020--Water security is becoming an urgent global challenge. Hundreds of millions of people already live in water-scarce regions, and the UN projects that by 2030 about half the world's population will be living in highly water-stressed areas. This will be a crisis even for developed countries like the U.S., where water managers in 40 states expect freshwater shortages within the next 10 years. As the global population and GDP grow, so will the demand for freshwater. And, with the continuing rise of global temperatures, water shortages will only get worse.

Desalination processes are increasingly being relied upon to augment water supplies. In fact, global desalination capacity is projected to double between 2016 and 2030. But these processes are expensive and can be harmful to the environment. The ultrahigh salinity brines that are the byproduct of desalination can be several times that of seawater salinity and its management options are especially challenging for inland desalination facilities such as those in Arizona, California, Florida, and Texas.

Over the past year, Columbia Engineering researchers have been refining their unconventional desalination approach for hypersaline brines--temperature swing solvent extraction (TSSE)--that shows great promise for widespread use. TSSE is radically different from conventional methods because it is a solvent-extraction-based technique that does not use membranes and is not based on evaporative phase-change: it is effective, efficient, scalable, and sustainably powered. In a new paper, published online June 23 in Environmental Science & Technology, the team reports that their method has enabled them to attain energy-efficient zero-liquid discharge (ZLD) of ultrahigh salinity brines--the first demonstration of TSSE for ZLD desalination of hypersaline brines.

"Zero-liquid discharge is the last frontier of desalination," says Ngai Yin Yip, an assistant professor of earth and environmental engineering who led the study. "Evaporating and condensing the water is the current practice for ZLD but it's very energy intensive and prohibitively costly. We were able to achieve ZLD without boiling the water off--this is a major advance for desalinating the ultrahigh salinity brines that demonstrates how our TSSE technique can be a transformative technology for the global water industry."

Yip's TSSE process begins with mixing a low-polarity solvent with the high salinity brine. At low temperatures (the team used 5 °C), the TSSE solvent extracts water from the brine but not salts (which are present in the brine as ions). By controlling the ratio of solvent to brine, the team can extract all the water from the brine into the solvent to induce the precipitation of salts--after all the water is "sucked" into the solvent, the salts form solid crystals and fall to the bottom, which can then be easily sieved out.

After the researchers separate out the precipitated salts, they warm up the water-laden solvent to a moderate temperature of around 70 °C. At this higher temperature, the solvent's solubility for water decreases and water is squeezed out from the solvent, like a sponge. The separated water forms a layer below the solvent and has much less salt than the initial brine. It can be readily siphoned off and the regenerated solvent can then be reused for the next TSSE cycle.

"We were not expecting TSSE to work as well as it did," Yip says. "In fact, when we were discussing its potential for ZLD, we thought just the opposite, that the process would likely give out at some point when there is just too much salt for it to keep working. So it was a happy surprise when I convinced lead researcher Chanhee Boo to give it a try, for the heck of it, on a Friday afternoon and we got such great results."

With a simulated (lab-prepared) brine feed of 292,500 part-per-million total dissolved solids, Yip's group was able to precipitate more than 90% of the salt in the original solution. In addition, the researchers estimated that the process used only about a quarter of the energy required for evaporation of water--a 75% energy savings compared to thermally evaporating the brine. They reused the solvent for several cycles with no noticeable loss in performance, demonstrating that the solvent was conserved and not expended during the process.

Then, to demonstrate the practical applicability of the technology, the team took a field sample of high-salinity brine, the concentrate of irrigation drainage water in California's Central Valley, where irrigation drainage water is difficult and costly to treat, and achieved ZLD with TSSE.

Conventional distillation methods require high-grade steam and are frequently supplemented with electricity to power vacuum pumps. Because TSSE requires only moderate temperature inputs, the low-grade thermal energy necessary can come from more sustainable sources, such as industrial waste heat, shallow-well geothermal, and low-concentration solar collectors.

"With the right solvent and right temperature conditions, we can provide cost-effective and environmentally sustainable concentrate management options for inland desalination facilities, utilizing brackish groundwater to alleviate the current and pending water stresses," Yip notes.

In addition to managing inland desalination concentrates, TSSE can also be used for other high salinity brines including flowback and produced water from oil and gas extraction, waste streams from steam-driven electric power stations, discharges from coal-to-chemical facilities, and landfill leachate. Yip's group is continuing to investigate the fundamental working mechanisms of TSSE, to engineer further improvements in its performance. This work includes further testing with real samples from the field, as well as optimization of the overall process.

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About the Study

The study is titled "Zero Liquid Discharge of Ultrahigh Salinity Brines with Temperature Swing Solvent Extraction."

Authors are:

Chanhee Boo,† Ian H. Billinge,† Xi Chen,† Kinnari M. Shah,† and Ngai Yin Yip*,†,‡

† Department of Earth and Environmental Engineering, Columbia University

‡ Columbia Water Center, Columbia University

The study was supported by the United States Bureau of Reclamation, Grant R19AC00111.

The authors declare no financial or other conflicts of interest.

LINKS:

Paper: https://pubs.acs.org/doi/10.1021/acs.est.0c02555

DOI: 10.1021/acs.est.0c02555

http://engineering.columbia.edu/

https://engineering.columbia.edu/press-releases/ngai-yin-yip-radical-desalination

https://engineering.columbia.edu/faculty/ngai-yin-yip

https://eee.columbia.edu/

https://yiplab-h2o-e-env.eee.columbia.edu/

Columbia Engineering

Columbia Engineering, based in New York City, is one of the top engineering schools in the U.S. and one of the oldest in the nation. Also known as The Fu Foundation School of Engineering and Applied Science, the School expands knowledge and advances technology through the pioneering research of its more than 220 faculty, while educating undergraduate and graduate students in a collaborative environment to become leaders informed by a firm foundation in engineering. The School's faculty are at the center of the University's cross-disciplinary research, contributing to the Data Science Institute, Earth Institute, Zuckerman Mind Brain Behavior Institute, Precision Medicine Initiative, and the Columbia Nano Initiative. Guided by its strategic vision, "Columbia Engineering for Humanity," the School aims to translate ideas into innovations that foster a sustainable, healthy, secure, connected, and creative humanity.

Mountain meadow restoration can bring birds back

POINT BLUE CONSERVATION SCIENCE

 

New Research: Mountain Meadow Restoration Can Bring Birds Back

In a new study led by scientists at Point Blue Conservation Science and in collaboration with The Institute for Bird Populations, authors evaluated the successes of mountain meadow restorations by analyzing eight years of bird data collected by field biologists. The authors concluded that, when "pond and plug" and similar techniques were followed, the number of birds of many species increased over time as habitat conditions improved.

The paper, published in Restoration Ecology, may prove of particular value to restoration practitioners, many of whom rely on peer-reviewed scientific journal articles to guide their work.

"This paper is the culmination of many years of work monitoring meadows. And it definitely increases the amount of evidence we have that one of the most commonly used approaches n is having the effects we want," says Brent Campos, a lead author of the study.

Restoration of degraded meadows and their streams aims to increase the amount of water flowing out of the stream channel during spring runoff and elevate groundwater levels in the dry season. Currently there are major efforts being made to restore meadows across the Sierra Nevada that have been degraded from overgrazing, agricultural use, or deliberate stream channel modifications. Evaluations of meadow restoration are needed to ensure objectives--such as increased biodiversity--are being met and identify modifications that may improve outcomes.

The study authors evaluated the expectation that meadow birds would increase in abundance following restoration. From 2009 to 2017 biologists sampled birds at 31 montane meadows in California previously restored using a common technique: partially filling the over-sized stream channel with meadow soils. The authors then assessed how the abundance of 12 species of meadow-associated birds changed from 1 to 18 years after restoration, and whether the amount of deciduous shrubs and trees (an indicator of bird habitat quality) at the time of restoration affected the rate of bird response.

According to the research, six of the twelve species studied increased in abundance after restoration, while five stayed roughly the same and one may have decreased. The amount of deciduous trees and shrubs at the restoration site at the time of restoration was a strong predictor of bird abundance. The study's authors concluded that both hydrologic measures (partially filling in degraded stream channels) and vegetative measures (planting shrubs and trees such as willows and cottonwoods at restoration sites) were helpful in creating habitat for birds, with the latter approach accelerating the positive impacts of restoration.

"Having access to one of the longest term datasets around for bird monitoring and meadow restoration was really essential to this paper," said Helen Loffland, a meadow bird specialist with The Institute for Bird Populations, and one of the paper's co-authors. "And it was heartening to see such positive responses from the birds in areas where both hydrologic and vegetative restoration measures were used."

"We know that restoration practitioners are out there trying to do the best job possible with limited funding," said Campos. "We hope that this new research will help them in their work restoring meadows' key functions of fostering biodiversity, reducing downstream flooding, purifying water, and storing carbon."

The study sites included areas throughout the Sierra including the Perazzo Meadows restoration site near Truckee, Red Clover Valley near Portola, and a restoration site in Tasmam Koyom (Humbug Valley) in Plumas County.

"It is pretty incredible to visit the Tasmam Koyom site, which is only 6 years out from the restoration completion and see such an abundance of birds," said Ryan Burnet, another co-author. "To see so many more song sparrows or yellow warblers is really encouraging. Normally, you'd need to wait 10 or even 20 years to see a biological response like that."

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The article, "Bird response to hydrologic restoration of montane riparian meadows" was published in the peer-reviewed journal Restoration Ecology (DOI 10.1111).

About Point Blue Conservation Science:

Point Blue advances conservation of birds, other wildlife and ecosystems through science, partnerships, and outreach. Our highest priority is to reduce the impacts of habitat loss, climate change, and other environmental threats while promoting nature-based solutions for wildlife and people, on land and at sea. Visit Point Blue at http://www.pointblue.org.