Earth

Nine years ago tomorrow--April 20, 2010--crude oil began leaking from the Deepwater Horizon drilling rig into the Gulf of Mexico in what turned out to be the largest marine oil spill in history. A long-term study suggests the oil is still affecting the salt marshes of the Gulf Coast, and reveals the key role that marsh grasses play in the overall recovery of these important coastal wetlands.

Conducting the study was a multi-institutional research team funded in part by the Gulf of Mexico Research Initiative, a 10-year independent program established through a $500 million financial commitment from BP. The team began sampling soon after the spill was finally contained, and continue their work today. Their most-recent article--in Estuaries and Coasts--reports on the first six and a half years of sampling post-spill.

Lead author on the study is John Fleeger, an emeritus professor at LSU. Co-authors are Rita Riggio, Irving Mendelssohn, Qianxin Lin, and Aixin Hou of LSU; David Johnson of William & Mary's Virginia Institute of Marine Science; Donald Deis of Atkins North America; Kevin Carman of the University of Nevada-Reno; Sean Graham of Nicholls State University; and Scott Zengel of Research Planning, Inc.

Johnson, an assistant professor at VIMS and expert in salt marsh invertebrates, says "Our study highlights the crucial role that plants play in the recovery of important links in the Gulf of Mexico's coastal food web." Those links ultimately connect to the fish and shellfish that support the region's economy and culture.

Two plants dominate healthy Gulf Coast salt marshes--the smooth cordgrass Spartina alterniflora and the black needlerush Juncus roemerianus. Also abundant on the marsh surface are single-celled, plant-like organisms that scientists collectively refer to as benthic microalgae, while a suite of small invertebrates--amphipods, copepods, nematodes, snails, worms, and others--swim, hop, and crawl among the grass blades or burrow in the underlying root zone.

The team studied these organisms by measuring their abundance and biomass in heavily oiled, moderately oiled, and oil-free areas of Louisiana's Barataria Bay, using both surface plots and shallow cores. Sampling took place at roughly 6-month intervals between 2011 and 2016.

The researchers' early sampling showed that nearly all the plants in heavily oiled areas died, while benthic microalgae and burrowing invertebrates suffered significant reductions. Their later sampling showed that marsh recovery was led by benthic microalgae and Spartina--which began to show significant above-ground growth within two to three years.

Importantly, it was only after Spartina started its comeback that recovery of the invertebrate community began in earnest. "Plants are the foundation of salt marshes," explains Johnson. "Marsh grasses facilitate colonization by burrowing invertebrates; fuel the food web, provide animal habitat, bind the soil, and slow water flow. Without plants there is no marsh, and there is no marsh recovery following a spill without plants leading the way."

If you plant it, they will come

The team's findings have important implications for responding to any future spills. Fleeger says "our findings indicate that mitigation strategies for any future spills should include the planting of foundation species such as Spartina."

Mendelssohn, a VIMS alumnus (M.A. '73), says that foundation species "enhance recovery by providing habitat and reducing sediment erosion." Over the longer term, he says, "plant growth enhances recovery by improving soil quality. Plants generate organic matter that accumulates belowground, while their roots and rhizomes release oxygen, bind sediments, and increase sediment volume. Breakdown of plant tissues also provides nutrients that further stimulate plant growth and beneficial microbial processes in the marsh."

A slow road to full recovery

Tempering the promise of marsh recovery via planting of grasses such as Spartina is the team's discovery that heavily oiled marsh sites remained less healthy than moderately oiled and oil-free sites more than 6 years after the Deepwater Horizon spill. Heavily oiled sites still had elevated concentrations of oil and its breakdown products, and showed slower growth of black needlerush, lower production of plant detritus and below-ground organic matter, and altered soil density. Populations of worms, juvenile snails, and other small invertebrates had also failed to fully recover.

Particularly troubling was the continued rarity of the polychaete worm Manayunkia aestuarina. One of the most abundant single species in the invertebrate community, this tube dweller is important to the health of marsh sediments, and plays a key role in the marsh food web as a major prey item for crabs, shrimp, and fish. "The near absence of this species could indicate significant alteration of ecological function at heavily oiled sites," says Johnson.

Also troubling is that projecting the observed pace of mash recovery into the future suggests that complete recovery at moderately and heavily oiled sites will likely take much longer than a decade. This is slower than reported in many previous studies of oil spills and their impacts on the marsh community.

"Previous work shows that oil spills in salt marshes can impact bottom-dwelling invertebrates for more than four decades," says Fleeger. "Long-term exposure to oil and its breakdown products may also decrease the sensitivity and resilience of these organisms to future spills," he adds.

On a brighter note, a previous study by Johnson and colleagues suggests that fertilization of Spartina plantings can enhance growth of both its stems and roots, thus aiding marsh recovery in the long term. "We're starting to see the salt marsh in the Gulf of Mexico rebound," says Johnson, "but it will likely be a decade or more before we see complete recovery."

Augusta, Ga. (April 19, 2019) - Identifying a protein that plays a key role in cancer cell growth is a first step toward the development of a targeted cancer therapy. It is especially promising when this protein is dispensable for the growth of normal cells. Their discovery that UNC45A fits these criteria has researchers, led by Dr. Ahmed Chadli, of the Georgia Cancer Center at Augusta University, excited about potential new cancer therapeutic strategies involving the inhibition of UNC45A.

UNC45A has long been recognized as a molecular chaperone, responsible for helping other proteins reach their functional state by guiding protein folding. It has a distinct role in cancer, however, where its over-expression in breast and ovarian cancer patient tissues correlates with grade and stage of the disease. After confirming that UNC45A is not required for the proliferation of normal breast cells, Dr. Chadli's group showed that in both cell and mouse models of breast cancer, UNC45A is required for cancer cell proliferation and tumor growth.

They published the underlying molecular mechanism in the Journal of Biological Chemistry, first by demonstrating that when they silenced UNC45A expression, an enzyme called NEK7 was also down-regulated, by 2-fold. NEK7 plays a key role in cell proliferation by orchestrating the proper separation of chromosomes during cell division. Either silencing UNC45A or deleting NEK7 resulted in decreased cancer cell proliferation, and adding NEK7 to UNC45A-silenced cells restored proliferative capacity.

Examining normal versus cancer cell lines and normal versus cancerous human breast tissues, the researchers observed significantly more UNC45A present inside (versus outside) of a cell's nucleus. They further discovered that in the nucleus, UNC45A interacts with a protein called the glucocorticoid receptor that, in turn, promotes NEK7 expression.

Due to NEK7's key role in cell division, they further explored the effect of silenced UNC45A on cell replication. Importantly, they found that silencing UNC45A, which results in NEK7 down-regulation, caused the cancer cells to undergo what is known as mitotic catastrophe and die, exemplifying the ultimate therapeutic goal.

This result was captured in a dramatic set of real-time videos of cell division in normal versus UNC45A-deficient cells. In normal cells (Movie 1), nuclear material, pictured in green, divides to form two separate cells, each surrounded by a cell membrane, which appears white. In UNC45A-deficient cells, (Movie 2), the nuclear material struggles to divide, and the division into two cells fails.

"Inhibiting UNC45A holds tremendous potential in the fight against solid tumors, since its role in proliferation does not seem to be necessary for the survival of normal cells," said Dr. Chadli. "How to inhibit its tumoral role apart from its normal functions is the topic of future studies that would improve our understanding of this molecular machine and how to harness its potential clinical application."

A study conducted by University of Arkansas researchers reveals that neurons in the motor cortex of the brain exhibit an unexpected division of labor, a finding that could help scientists understand how the brain controls the body and provide insight on certain neurological disorders.

The researchers studied the neurons in the motor cortex of rats and found that they fall into two groups: "externally focused" neurons that communicate with and control different parts of the body and "internally focused" neurons that only communicate with each other and don't send signals to other parts of the body. The researchers also found that when they increased inhibition of neurons in the motor cortex, the externally focused neurons switched to internally focused.

"Alterations in inhibitory signaling are implicated in numerous brain disorders," explained Woodrow Shew, associate professor of physics. "When we increased inhibition in the motor cortex, those neurons responsible for controlling the body become more internally oriented. This means that the signals that are sent to the muscles from the motor cortex might be corrupted by the 'messy' internal signals that are normally not present."

Rett Syndrome, a rare but severe neurological disorder, is one of the brain disorders associated with an increase in inhibition. Shew plans to further research the implications of these findings for Rett Syndrome.

CHAMPAIGN, Ill. -- Oxidants found within living organisms are byproducts of metabolism and are essential to wound-healing and immunity. However, when their concentrations become too high, inflammation and tissue damage can occur. University of Illinois engineers have developed and tested a new drug-delivery system that senses high oxidant levels and responds by administering just the right amount of antioxidant to restore this delicate balance.

The findings are published in the journal Small.

Many pharmaceuticals include specialized polymers and particles that control the timing or concentration of the drug released once administered, the researchers said. However, these additives can hamper crystallization during the manufacturing phase of some drugs - like antioxidants - causing them to dissolve in the body in an uncontrolled manner.

"We saw an opportunity here to develop a different kind of drug-delivery system that could sense the level of oxidant in a system and respond by administering antioxidant as needed," said chemical and biomolecular engineering professor and study co-author Hyunjoon Kong.

Kong and his team found a way to assemble crystals of catechin - the bright green antioxidant found in green tea - using a polymer that can sense when oxidant concentrations become too high. The researchers tested the responsiveness of the resulting catechin crystal-containing polymer in the common freshwater planktonic crustacean Daphnia magna, the water flea.

"Heart rate is an indication of the extent to which potentially toxic chemicals influence physiology in water fleas," Kong said. "Daphnids are often used to monitor environmental impacts on ecological systems, and because their hearts are similar to those of vertebrates, they are also used to evaluate the efficacy of cardioprotective drugs."

The researchers exposed the daphnids to water contaminated with sublethal concentrations of the natural oxidant hydrogen peroxide while monitoring their heart rate. They found that the daphnids' mean heart rates dropped from 348 to 290 and 277 beats per minute, depending on the concentration of hydrogen peroxide used.

When the team added the new catechin crystal assembled with polymer to the experiment, the water fleas eventually recovered a close-to-normal heart rate.

Beyond the potential pharmaceutical uses for the new polymer, Kong's group is looking into its use for curtailing the impact of highly oxidizing chemicals in natural waterways.

"Hydrogen peroxide is often used to clean water fouled by excessive algae, and this raises concern about how the oxidant may be affecting living organisms in water," he said. "We think this new antioxidant-delivery system could be used to address the problem of over-oxidized natural waters."

The researchers plan to push ahead with developing the polymer for pharmaceutical and environmental uses. "This study proved a concept, but we have more work to do," Kong said. "There is concern over the safety of the specific polymer we used - polyethylenimine diselenide - but we are getting close to finding a viable replacement."

WASHINGTON, D.C., April 14, 2019 -- After watching YouTube videos of people supercooling water in a bottle and then triggering it to freeze by banging it, something about this concept solidified for Matthew M. Szydagis, an assistant professor of physics at the University at Albany, State University at New York, especially when he saw it again during the Disney movie "Frozen."

During the 2019 American Physical Society April Meeting in Denver, Szydagis will describe how this inspired him to explore whether a subatomic particle like dark matter can trigger the freezing of supercooled water. Read more at https://arxiv.org/pdf/1807.09253.pdf.

"All of my work is motivated by the search for dark matter, a form of matter we're sure is out there because we can observe its indirect gravitational effects," Szydagis said. "It makes up a significant fraction of the universe, but we have yet to uncover direct, conclusive and unambiguous evidence of it within the lab."

If water is clean enough -- low in impurities, such as dust particulates -- and placed in a smooth enough container, Szydagis explained, it can be cooled below its freezing point of 0 C (32 F) without freezing.

"This is called 'supercooling' and is similar to how water can be easily superheated in the microwave, essentially heated above its boiling point without actually boiling. It's simply the reverse," he said. "The water ends up, in either of these cases, in a state known as 'metastability,' neither unstable nor quite stable either."

A disturbance can trigger the phase transition, freezing and crystallization, in this case. "This isn't ordinary freezing, and it forms white snow instead of clear ice," he added. "We cooled liquid water to as cold as -20 C (-4 F). in our lab without it freezing. It isn't the same as freezing point depression, like when you salt your sidewalk, because the water was pure and not contaminated with impurities on purpose."

The group demonstrated that certain forms of particles hitting the water can microscopically (subatomically) cause it to freeze if it's supercooled first. "Some particles like neutrons can even scatter multiple times within the water," Szydagis said. "We were able to show this not only with commercially available sources of particles, but also a Fiestaware 'radioactive red' plate with orange uranium-based paint from the 1950s."

They created a new detector based on the supercooled water, dubbed the "snowball chamber" because that matches well with "bubble" and "cloud" chambers, which are technologies from the early- to mid-20th century that use boiling and condensation.

Supercooled water certainly isn't new; it's been studied for numerous decades by chemists and condensed matter physicists, down to -40 C (-40 F). There are even publications about it dating back more than 100 years old.

"But we managed to discover a new property of supercooled water," Szydagis said. "To our great surprise, we found that some particles (neutrons) but not others (gamma rays) trigger freezing. Since this is basic research that has never been done before, there was no guarantee it would work. It was a 'let's try it and see' approach -- the scientific method in its most basic form. Not only do we have a new detector of fundamental particles, but potentially of dark matter because neutrons are thought to emulate it."

The group envisions numerous other potential implications for their discovery, including detecting nuclear weapons in cargo for homeland security, understanding cloud formation, and providing clues as to how certain mammalian species hibernate, supercooling their blood somehow.

New research being presented at this year's European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Amsterdam, the Netherlands (13-16 April), suggests that mode of delivery influences the development of the microbial composition of the gut (i.e. the gut microbiota) in infants, independently of a mother's use of antibiotics. This, in turn, may affect infants' respiratory health during the first year of life.

The prospective Microbiome Utrecht Infant Study (initiated by the Spaarne Gasthuis hospital in Hoofddorp in collaboration with the University Medical Centre Utrecht, the Netherlands) involving 120 infants, found that children born by caesarean section (C-section) had a delay in the normal development of their gut microbiota, and a higher abundance of potentially harmful bacteria, compared to infants delivered vaginally--which could be the mechanism driving the increased risk in respiratory infections.

Over 1000 different types of bacteria live in the gut, where they elicit important functions for health, for example helping to digest food, stimulating the development of the immune system, and protecting against infection.

After birth, infants become colonised by an increasing diversity of gut microbes until a relatively stable state is reached. The pace and pattern by which infants acquire their gut microbiome is thought to have a substantial impact on health in later life. Disruption of the normal development of the gut microbiome has been linked with a range of diseases including irritable bowel disease, asthma, allergies and cancer.

Previous research indicates that early life microbiota development is influenced by mode of delivery, although it has been suggested that this depends mostly on maternal antibiotic exposure.

To assess the independent effects of mode of delivery, Marta Reyman, from the Wilhelmina Children's Hospital, Utrecht, the Netherlands, and colleagues analysed the gut microbiota development in 46 C-section and 74 vaginally delivered infants using stool samples collected 10 times during their first year of life. Antibiotic administration to mothers undergoing a C-section was postponed until after clamping of the umbilical cord. Maternal stool samples were also examined 2 weeks after delivery.

Analyses showed that gut microbiota composition differed significantly between C-section and vaginally delivered infants in the first year, which was most pronounced shortly after birth. This was accompanied by measurable faecal seeding (transfer of maternal vaginal microbes) from mother to child in vaginally delivered infants, but not in children born by C-section.

In infants born by C-section, the gut microbiota was less stable and the development of the health-promoting bacterial species Bifidobacterium spp. was delayed compared to vaginally delivered children. Additionally, infants born by C-section had much higher levels of potential pathogenic gut bacteria, irrespective of length of hospital stay after birth, feeding type, and antibiotic use.

Interestingly, the researchers also found that the gut microbiota early in life was associated with the total number of respiratory infections over the first year.

"Our findings suggest that mode of delivery affects the developing infant gut microbiota, independent of a mother's use of antibiotics during birth. Compared to vaginally delivered infants, children born by C-section have different trajectories of bacterial colonisation, which could have implications for their future respiratory health", says Marta Reyman, who is the PhD student on this study. "Further research and larger studies will be needed to fully understand the consequences of these changes. The insights gained might help to design strategies to prevent health-related problems following birth by C-section."

The major limitation of this study is the use of 16S rRNA based sequencing, which does not allow annotation of bacteria on species level, or generate results based on genetic content of microbial communities.

EUGENE, Ore. - April 11, 2019 - By drilling holes into a thin two-dimensional sheet of hexagonal boron nitride with a gallium-focused ion beam, University of Oregon scientists have created artificial atoms that generate single photons.

The artificial atoms - which work in air and at room temperature - may be a big step in efforts to develop all-optical quantum computing, said UO physicist Benjamín J. Alemán, principal investigator of a study published in the journal Nano Letters.

"Our work provides a source of single photons that could act as carriers of quantum information or as qubits. We've patterned these sources, creating as many as we want, where we want," said Alemán, a member of the UO's Material Science Institute and Center for Optical, Molecular, and Quantum Science. "We'd like to pattern these single photon emitters into circuits or networks on a microchip so they can talk to each other, or to other existing qubits, like solid-state spins or superconducting circuit qubits."

Artificial atoms were discovered three years ago in flakes of 2D hexagonal boron nitride, a single insulating layer of alternating boron and nitrogen atoms in a lattice that is also known as white graphene. Alemán is among numerous researchers who are using that discovery to produce and use photons as sources of single photons and qubits in quantum photonic circuits.

Traditional approaches for using atoms in quantum research have focused on capturing atoms or ions, and manipulating their spin with lasers so they exhibit quantum superposition, or the ability to be in a simultaneous combination of "off" and "on" states. But such work has required working in vacuum in extremely cold temperatures with sophisticated equipment.

Motivated by the observation that artificial atoms are frequently found near an edge, Alemán's team, supported by the National Science Foundation, first created edges in the white graphene by drilling circles 500 nanometers wide and four nanometers deep.

The devices were then annealed in oxygen at 850 degrees Celsius (1,562 degrees Fahrenheit) to remove carbon and other residual material and to activate the emitters. Confocal microscopy revealed tiny spots of light coming from the drilled regions. Zooming in, Alemán's team saw that the individual bright spots were emitting light at the lowest possible level--a single photon at a time.

The individual photons conceivably could be used as tiny, ultra-sensitive thermometers, in quantum key distribution, or to transfer, store and process quantum information, Alemán said.

"The big breakthrough is that we've discovered a simple, scalable way to nanofabricate artificial atoms onto a microchip, and that the artificial atoms work in air and at room temperature," Alemán said. "Our artificial atoms will enable lots of new and powerful technologies. In the future, they could be used for safer, more secure, totally private communications, and much more powerful computers that could design life-saving drugs and help scientists gain a deeper understanding of the universe through quantum computation."

Two-dimensional (2D) semiconductors are promising for quantum computing and future electronics. Now, researchers can convert metallic gold into semiconductor and customize the material atom-by-atom on boron nitride nanotubes.

Gold is a conductive material already widely used as interconnects in electronic devices. As electronics have gotten smaller and more powerful, the semiconducting materials involved have also shrunk. However, computers have gotten about as small as they can with existing designs -- to break the barrier, researchers dive into the physics underlying quantum computing and the unusual behaviors of gold in quantum mechanics.

Researchers can convert gold into semiconducting quantum dots made of a single layer of atoms. Their energy gap, or bandgap, is formed by the quantum confinement -- a quantum effect when materials behave like atoms as their sizes get so small approaching the molecular scale. These 2D gold quantum dots can be used for electronics with a bandgap that is tunable atom-by-atom.

Making the dots with monolayer of atoms is tricky and the bigger challenge is customizing their properties. When laid out on boron nitride nanotubes, researchers from Michigan Technological University have found that they can get gold quantum dots to do the near-impossible. The mechanisms behind getting gold dots to clump atom-by-atom is the focus of their new paper, recently published in ACS Nano.

Yoke Khin Yap, professor of physics at Michigan Tech, led the study. He explains that the behavior his team observed -- atomic-level manipulation of gold quantum dots -- can be seen with a scanning transmission electron microscope (STEM). The STEM's high-powered beam of electrons enables researchers like Yap to watch atomic movement in real-time and the view reveals how gold atoms interact with the surface of boron nitride nanotubes. Basically, the gold atoms glide along the surface of the nanotubes and, they stabilize in a hover just above the hexagon honeycomb of the boron nitride nanotubes.

The atomic skiing and stopping is related to the so-called energy selective deposition. In the lab, the team takes an array of boron nitride nanotubes and runs a gold-laden mist past it; the gold atoms in the mist either stick as multilayered nanoparticles or bounce off the nanotube, but some of the more energetic ones glide along the circumference of the nanotube and stabilize, then start to clump into monolayers of gold quantum dots. The team shows that gold preferentially deposits behind other gold particles that have stabilized.

"The surface of boron nitride nanotubes are atomically smooth, there are no defects on the surface, it's a neatly arranged honeycomb," Yap said, adding that the nanotubes are chemically inert and there is no physical bond between the nanotubes and gold atoms. "It's much like skiing: You can't ski on a bumpy and sticky hill with no snow, ideal conditions make it much better. The smooth surface of the nanotubes is like fresh powder."

The search for new materials for future electronics and quantum computing has led researchers down many paths. Yap hopes that by demonstrating the effectiveness of gold, other researchers will be inspired to pay attention to other metal monolayers at the molecular-scale.

"This is a dream nanotechnology," Yap said. "It is a molecular-scale technology tunable by atom with an ideal bandgap in the visible light spectra. There is a lot of promise in electronic and optical devices."

The team's next steps include further characterization and incorporating device fabrication to demonstrate all-metal electronics. Potentially, monolayers of metal atoms could make up the entirety of future electronics, which will save a lot of manufacturing energy and materials.

PITTSBURGH (April 11, 2019) ... In 1942, Ludwig Prandtl--considered the father of modern aerodynamics--published "Führer durch die Strömungslehre," the first book of its time on fluid mechanics and translated to English from the German language in 1952 as "Essentials of Fluid Mechanics." The book was uniquely successful such that Prandtl's students continued to maintain and develop the book with new findings after his death. Today, the work is available under the revised title "Prandtl--Essentials of Fluid Mechanics," as an expanded and revised version of the original book with contributions by leading researchers in the field of fluid mechanics.

Over the years, the last three pages of Prandtl's original book, focusing on mountain and valley winds, have received some attention from the meteorology research community, but the specific pages have been largely overlooked by the fluid mechanics community to the point that the content and the exact mathematical solutions have disappeared in the current expanded version of the book. But today in the age of supercomputers, Inanc Senocak, associate professor of mechanical engineering and materials science at the University of Pittsburgh Swanson School of Engineering, is finding new insights in Prandtl's original work, with important implications for nighttime weather prediction in mountainous terrain.

Drs. Senocak and Cheng-Nian Xiao, a postdoctoral researcher in Dr. Senocak's lab, recently authored a paper titled "Stability of the Prandtl Model for Katabatic Slope Flows," published in the Journal of Fluid Mechanics (DOI: 10.1017/jfm.2019.132). The researchers used both linear stability theory and direct numerical simulations to uncover, for the first time, fluid instabilities in the Prandtl model for katabatic slope flows.

Katabatic slope flows are gravity-driven winds common over large ice sheets or during nighttime on mountain slopes, where cool air flows downhill. Understanding those winds are vital for reliable weather predictions, which are important for air quality, aviation and agriculture. But the complexity of the terrain, the stratification of the atmosphere and fluid turbulence make computer modeling of winds around mountains difficult. Since Prandtl's model does not set the conditions for when a slope flow would become turbulent, that deficiency makes it difficult, for example, to predict weather for the area around Salt Lake City in Utah, where the area's prolonged inversions create a challenging environment for air quality.

"Now that we have more powerful supercomputers, we can improve upon the complexity of the terrain with better spatial resolutions in the mathematical model," says Dr. Senocak. "However, numerical weather prediction models still make use of simplified models that have originated during a time when computing power was insufficient."

The researchers found that while Prandtl's model is prone to unique fluid instabilities, which emerge as a function of the slope angle and a new dimensionless number, they have named the stratification perturbation parameter as a measure of the disturbance to the background stratification of the atmosphere due to cooling at the surface. The concept of dimensionless numbers, for example the Reynolds number, plays an important role in thermal and fluid sciences in general as they capture the essence of competing processes in a problem.

An important implication of their finding is that, for a given fluid such as air, dynamic stability of katabatic slope flows cannot simply be determined by a single dimensionless parameter alone, such as the Richardson number, as is practiced currently in the meteorology and fluids dynamics community. The Richardson number expresses a ratio of buoyancy to the wind shear and is commonly used in weather prediction, investigating currents in oceans, lakes and reservoirs, and measuring expected air turbulence in aviation.

"An overarching concept was missing, and the Richardson number was the fallback," says Dr. Senocak. "We're not saying the Richardson number is irrelevant, but when a mountain or valley is shielded from larger scale weather motions, it doesn't enter into the picture. Now we have a better way of explaining the theory of these down-slope and down-valley flows."

Not only will this discovery be important for agriculture, aviation and weather prediction, according to Dr. Senocak, but it will also be vital for climate change research and associated sea-level rise, as accurate prediction of katabatic surface wind profiles over large ice sheets and glaciers is critical in energy balance of melting ice. He notes that even in the fluids dynamics community, the discovery of this new surprising type of instability is expected to arouse a lot of research interest.

Next, Dr. Senocak is advising and sponsoring a senior design team to see if researchers can actually observe these fluid instabilities in the lab at a scale much smaller than a mountain.

A new technique for the decontamination of organs before transplantation using ultraviolet and red light irradiation has been developed by Brazilian and Canadian researchers and is described in an article published in the journal Nature Communications.

The research is supported by São Paulo Research Foundation - FAPESP and has been partially conducted at the Optics and Photonics Research Center (CEPOF), hosted by the University of São Paulo (USP) at São Carlos in São Paulo State (Brazil).

"This biophotonic technique is revolutionary, as it helps avoid the transmission of diseases during organ transplantation," said Vanderlei Bagnato, Full Professor at the University of São Paulo, Director of its São Carlos Physics Institute (IFSC-USP), and principal investigator for CEPOF, one of the Research, Innovation and Dissemination Centers (RIDCs) supported by FAPESP.

Bagnato's group partnered with researchers at the University of Toronto in Canada, which has the world's largest lung transplantation program, having performed 197 such surgeries in 2018 alone. According to the thoracic surgeon Marcelo Cypel, who heads the service, the number of transplants could be higher if organs could be decontaminated, especially when the prospective donor has a chronic viral infection such as hepatitis C.

"Ten patients have so far been tested [using the biophotonic therapy]," Cypel said. "The new technique significantly reduced transplant organ viral load in eight of these patients. The procedure all but eliminated the virus in two others."

The method described in the article ("Inactivating hepatitis C virus in donor lungs using light therapies during normothermic ex vivo lung perfusion") involves ultraviolet and red light irradiation to reduce viral and bacterial loads in infected organs to prevent the transmission of diseases such as hepatitis to transplant recipients.

In addition to FAPESP, the research was also funded by the Canadian Institutes of Health Research, the Toronto General and Western Hospital Foundation, and Brazil's National Council for Scientific and Technological Development (CNPq).

According to Bagnato, the technique was initially developed to treat lungs but is being adapted for livers and kidneys. "This should greatly improve postoperative conditions for transplant recipients," he said. "It will also enable us to use organs that we must currently reject because of the level of contamination."

Two-step decontamination

Lungs are decontaminated before transplantation by having the blood replaced by a preservation liquid in a procedure known as perfusion that was developed in Canada by Cypel.

"Perfusion reduces the viral and bacterial loads but cannot eliminate them completely. As a result, the patient has to be treated with antibiotics and antivirals for three months after the transplant," Cypel explained.

"Thinking about ways to further reduce or eliminate the viral load in organs for transplantation, specifically hepatitis C virus, I considered the possibility of using ultraviolet light decontamination methods, which are commonly employed to decontaminate blood, for example. So about four years ago, we began partnering with Bagnato and his team at São Carlos. He and his colleagues came over to visit us and study the technique. Only a month later they sent us the first prototype of the ultraviolet irradiation decontamination machine."

"The biophotonic decontamination technique developed at our São Carlos laboratory consists of two specific procedures performed concurrently," said Cristina Kurachi, a professor at IFSC-USP and a participant in the project.

During perfusion, while the researchers make the liquid circulate in the lung to be transplanted, they add molecules to the lung tissue, and biophotonic decontamination takes place directly in the organ through irradiation with red light with a wavelength of 660 nanometers (nm) until photodynamic oxidation eliminates the microorganisms in the tissue.

At the same time, the viral load is flushed away by the circulating liquid, which is continuously decontaminated by ultraviolet irradiation with a wavelength of 254 nm.

"The ultraviolet irradiation directly destroys microorganisms by breaking down the molecules present in bacteria and viruses. The bacteria are killed, and the viruses are completely inactivated. Red light irradiation decontaminates indirectly via photosensitization," Kurachi said.

This biophotonic therapy involves the introduction of a photosensitizing drug into the perfusion liquid. Activation of the drug requires oxygen molecules (present in viruses) and red light irradiation at a specific wavelength (660 nm). When the photosensitizing drug is bathed in this red light, its molecules absorb energy, which is transferred to the oxygen molecules in the virus, making them highly oxidized. This causes irreversible damage to the membranes and genetic material of several viruses, including hepatitis C virus and HIV-1.

"The perfusion solution is special and very expensive," Bagnato said. "It's made in such a way as to preserve the organ. Because of the cost, as little as possible is used in the procedure. Thanks to the technique and equipment we've developed, a liter of the perfusate can be flushed through the organ hundreds of times to remove the contaminants completely."

The method was first tested on human lungs rejected for transplantation to determine whether the tissue viral load could be reduced by irradiation. According to Cypel, the viral load was found to have fallen drastically after the procedure.

"The next step was to subject pig lungs to the same procedure and then transplant them to see if the procedure caused any biochemical or morphological damage to tissue. It did not," Cypel said.

Finally, the technique was tested on patients. "In the first ten transplants we performed, the new technique eliminated hepatitis C virus from organs donated to two patients. In the other eight patients, viral load fell sharply after surgery but rose again seven days later, and the patients had to be given antiviral treatment for three months," he said.

"An important finding was that when the virus wasn't eliminated it reappeared in the patient's lab tests after seven days. With this information, we've since performed two other transplants where antiviral treatment concentrated in the first week after the operation. The virus was eliminated in both cases," Cypel said.

According to Bagnato, this biophotonic therapy will be refined to assure even sharper reductions in the viral and bacterial loads, increasing the chances of successful transplants. "Our aim is to have light-based therapy eliminate all viral and bacterial contaminants in organs to be transplanted. If so, it may even be possible to do without the perfusate," he said.

The clinical part of the project is being conducted by Cypel and his group in Toronto. The researchers at IFSC-USP designed the new biophotonic technique, developed the instruments, and are participating in the analysis of the results. In addition to Bagnato and Kurachi, the Brazilian team at IFSC-USP also includes Natalia Inada.

A patent application has been filed in Canada, and two multinationals have expressed an interest in studying the possibility of producing and marketing the equipment. The researchers are now working on the implementation of a liver and kidney decontamination program in Brazil.

"All this has only been possible thanks to the philosophy introduced by FAPESP's RIDC program, which encouraged us to collaborate internationally and at the same time produce practically relevant knowledge," Bagnato said.

(Boston)--Using an experimental positron emission tomography (PET) scan, researchers have found elevated amounts of abnormal tau protein in brain regions affected by chronic traumatic encephalopathy (CTE) in a small group of living former National Football League (NFL) players with cognitive, mood and behavior symptoms. The study was published online in the New England Journal of Medicine.

The researchers also found the more years of tackle football played (across all levels of play), the higher the tau protein levels detected by the PET scan. However, there was no relationship between the tau PET levels and cognitive test performance or severity of mood and behavior symptoms.

"The results of this study provide initial support for the flortaucipir PET scan to detect abnormal tau from CTE during life. However, we're not there yet," cautioned corresponding author Robert Stern, PhD, professor of neurology, neurosurgery and anatomy and neurobiology at Boston University School of Medicine (BUSM). "These results do not mean that we can now diagnose CTE during life or that this experimental test is ready for use in the clinic."

CTE is a neurodegenerative disease that has been associated with a history of repetitive head impacts, including those that may or may not be associated with concussion symptoms in American football players. At this time, CTE can only be diagnosed after death by a neuropathological examination, with the hallmark findings of the build-up of an abnormal form of tau protein in a specific pattern in the brain. Like Alzheimer's disease (AD), CTE has been suggested to be associated with a progressive loss of brain cells. In contrast to AD, the diagnosis of CTE is based in part on the pattern of tau deposition and a relative lack of amyloid plaques.

The study was conducted in Boston and Arizona by a multidisciplinary group of researchers from BUSM, Banner Alzheimer's Institute, Mayo Clinic Arizona, Brigham and Women's Hospital and Avid Radiopharmaceuticals. Experimental flortaucipir PET scans were used to assess tau deposition and FDA-approved florbetapir PET scans were used to assess amyloid plaque deposition in the brains of 26 living former NFL players with cognitive, mood, and behavior symptoms (ages 40-69) and a control group of 31 same-age men without symptoms or history of traumatic brain injury. Results showed that the tau PET levels were significantly higher in the former NFL group than in the controls, and the tau was seen in the areas of the brain which have been shown to be affected in post-mortem cases of neuropathologically diagnosed CTE.

Interestingly, the former player and control groups did not differ in their amyloid PET measurements. Indeed, only one former player had amyloid PET measurements comparable to those seen in Alzheimer's disease.

"Our findings suggest that mild cognitive, emotional, and behavioral symptoms observed in athletes with a history of repetitive impacts are not attributable to AD, and they provide a foundation for additional research studies to advance the scientific understanding, diagnosis, treatment, and prevention of CTE in living persons, said co-author, Eric Reiman, MD, Executive Director of Banner Alzheimer's Institute in Phoenix, Arizona. "More research is needed to draw firm conclusions, and contact sports athletes, their families, and other stakeholders are waiting.

With support from NIH, the authors are working with additional researchers to conduct a longitudinal study called the DIAGNOSE CTE Research Project in former NFL players, former college football players, and persons without a history of contact sports play to help address these and other important questions. Initial results of that study are expected in early 2020.

The global burden of COPD is high, and prevalence of nonsmokers with COPD has been increasing. In a study to be presented at CHEST Congress Thailand 2019, researchers in Nagpur, India, sought to describe the characteristics of nonsmoking patients with COPD and to determine associated comorbidities and exposures.

Researchers examined 180 nonsmoking patients with COPD between the years of 2016 and 2018. Each patient was categorized into either mild, moderate, severe and very severe COPD, based on their responses to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline questionnaires.

In this cohort, the percentage of mild, moderate, severe and very severe patients were 26%, 53%, 58% and 43%, respectively. The most common comorbidity among nonsmoker COPD was hypertension (34.4%) followed by diabetes mellitus (17.8%). Most of the patients (61%) lived in rural areas, while 38% belonged to urban areas. Forty six percent of patients had exposure to biomass gas, while 26% had exposure to toxic gases. These results support that exposure to biomass fuel is a major contributing factor to COPD and a higher risk among the rural population.

"Exposure to industrial smoke, environmental pollution and household smoke are major contributors for COPD in nonsmokers," says Dr. Sameer Arbat, lead researcher. "There is a need to study this subset of nonsmokers having COPD further to determine the true cause of this increase."

Further results from this study will be shared at CHEST Congress 2019 in Bangkok on Friday, April 12, at 3:00 p.m., in the Exhibition Hall. The study abstract can be viewed on the journal CHEST® website.

Led by the University of York's Mental Health Addictions Research Group, SCIMITAR+ is the largest ever trial to support smoking cessation among people who use mental health services. Smoking rates among people with mental health conditions are among the highest of any group having changed little over the last 20 years, while other smokers have quit. This new study demonstrates that with the right support this inequality could be a thing of the past.

Mental health nurses were trained to deliver evidence based behavioural support to smokers with severe mental illness in smokers' homes, alongside providing access to Nicotine Replacement Therapy (NRT) and medications. The researchers found that smokers who received this support were more than twice as likely to have quit six months following the intervention than smokers who had received standard care, usually a referral to the local stop smoking service.

Professor Simon Gilbody, lead researcher from the University of York's Department of Health Sciences and Hull York Medical School, said: "People with mental health conditions die on average 10 - 20 years earlier than the general population, and smoking is the single largest factor in this shocking difference. Our results show that smokers with severe mental illness can successfully quit when given the right support. We hope our findings will mean that this specialist support is available to everyone who might benefit."

The NHS Long Term Plan published in January commits to developing a dedicated pathway of support to help long-term users of mental health services quit smoking. The Mental Health and Smoking Partnership recommends that the learning from this study is incorporated into routine practice nationally.

Professor Tim Kendall, National Clinical Director for Mental Health at NHS England, said: "This exciting new research will help inform our work to implement the NHS Long Term Plan and deliver the best possible support for smokers with mental health conditions to quit. Narrowing the gap in life expectancy experienced by people with mental health conditions must be a priority for everyone working in the NHS and helping smokers to quit is a key route to achieving this."

Ann McNeill, Professor of Tobacco Addiction at King's College London and co-chair of the Mental Health and Smoking Partnership, said: "The Mental Health and Smoking Partnership welcome the findings from this study. Smokers with severe mental illness have been ignored for far too long - and it is fantastic to see that changing. We hope that NHS England will take these findings into account when implementing the ambition of the NHS Long Term Plan. Most smokers with a mental health condition live in the community, meaning community and primary care services also need to step-up the support they're providing if we're to narrow the gap in life expectancy. SCIMITAR shows how this can be done effectively."

Orlando, Fla. (April 8, 2019) - Antioxidants such as vitamin C could help reduce harmful effects from hexavalent chromium, according to a new study performed with human cells. The contaminant, which is often produced by industrial processes, was featured in the biographical movie Erin Brockovich.

Federal data from nationwide drinking water tests show that the compound contaminates water supplies for more than 200 million Americans in all 50 states. The concentration of hexavalent chromium that is safe for drinking water is now under review by the U.S. Environmental Protection Agency.

"This is the first study to use human cells to test the effects of hexavalent chromium and protection by antioxidants," said Tim Mayotte, an undergraduate student at Olivet Nazarene University who performed the study. "If the new findings are further validated and go on to clinical trials, it might be possible to treat at-risk water sources with antioxidants like vitamin C to lower the risk for cancer caused by hexavalent chromium."

Mayotte will present this research at the American Society for Biochemistry and Molecular Biology annual meeting during the 2019 Experimental Biology meeting to be held April 6-9 in Orlando, Fla.

In a study designed to find out whether antioxidants might prevent cell toxicity, the researchers exposed two types of human cells to various concentrations of hexavalent chromium. They observed toxic effects for both cell types at 200 parts per billion (ppb) or higher concentrations of hexavalent chromium. However, this toxicity could be blocked by vitamin C at 10 parts per million (ppm) or the antioxidant epigallocatechin gallate at 15 (ppm). Epigallocatechin gallate is the primary antioxidant found in green tea.

In other experiments, the researchers saw DNA mutations in bacteria exposed to 20 ppb or more of hexavalent chromium. However, these mutations didn't occur when the bacteria were also treated with 20 ppm of vitamin C.

The new findings reveal that an oxidative mechanism is likely responsible for the contaminant's toxicity, which could be prevented by treating the water with antioxidants. These results could help inform water quality monitoring and regulation.

Tim Mayotte will present the findings from 11:45 a.m. -1:00 p.m. Monday, April 8, in Exhibit Hall-West Hall B, Orange County Convention Center (poster E238 634.9) (abstract). Contact the media team for more information or to obtain a free press pass to attend the meeting.

The field of materials science has become abuzz with "metal-organic frameworks" (MOFs), versatile compounds made up of metal ions connected to organic ligands, thus forming one-, two-, or three-dimensional structures. There is now an ever-growing list of applications for MOF, including separating petrochemicals, detoxing water from heavy metals and fluoride anions, and getting hydrogen or even gold out of it.

But recently, scientists have begun making MOFs, made of building blocks that typically make up biomolecules, e.g. amino acids for proteins or nucleic acids for DNA. Apart from the traditional MOF use in chemical catalysis, these biologically derived MOFs can be also used as models for complex biomolecules that are difficult to isolate and study with other means.

Now, a team of chemical engineers at EPFL Valais Wallis have synthesized a new biologically-derived MOF that can be used as a "nanoreactor" - a place where tiny, otherwise-inaccessible reactions can take place. Led by Kyriakos Stylianou, scientists from the labs of Berend Smit and Lyndon Emsley constructed and analyzed the new MOF with adenine molecules - one of the four nucleobases that make up DNA and RNA.

The reason for this was to mimic the functions of DNA, one of which include hydrogen-bonding interactions between adenine and another nucleobase, thymine. This is a critical step in the formation of the DNA double helix, but it also contributes to the overall folding of both DNA and RNA inside the cell.

Studying their new MOF, the researchers found that thymine molecules diffuse within its pores. Simulating this diffusion, they discovered that thymine molecules were hydrogen-bonded with adenine molecules on the MOF's cavities, meaning that it was successful in mimicking what happens on DNA.

"The adenine molecules act as structure-directing agents and 'lock' thymine molecules in specific positions within the cavities of our MOF," says Kyriakos Stylianou. So the researchers took advantage of this locking and illuminated the thymine-loaded MOF - a way to catalyze a chemical reaction.

As a result, the thymine molecules could be dimerized into a di-thymine product, which the scientists were able to be isolate - a huge advantage, given that di-thymine is related to skin cancer and can now be easily isolated and studied.

"Overall, our study highlights the utility of biologically derived MOFs as nanoreactors for capturing biological molecules through specific interactions, and for transforming them into other molecules," says Stylianou.