Tech

Anyone who's read "The Lorax" will recognize that certain species serve as the foundation of their ecosystems. When the truffula trees disappear, so to do the swomee-swans and bar-ba-loots. However, the same is not necessarily true the other way around.

Scientists have taken a growing interest in ecological stability -- the factors that make an ecosystem robust against pressures and perturbations -- especially in light of human impacts like climate change and pollution. Though many presume that the stability of an ecosystem's foundation species will promote stability overall, few have quantified this effect as of yet.

Researchers at UC Santa Barbara's Marine Science Institute (MSI) have leveraged long-term ecological data to probe this question in Southern California's kelp forests. They found a correlation between the stability of giant kelp and the stability in understory seaweed and seafloor invertebrates, such as sponges, as well as higher biodiversity over all. Their results appear in the journal Ecology.

A foundation species shapes its entire environment and defines an ecosystem. "The ecosystem in which they live is often named after them, like oyster beds, coral reefs, or redwood forests," said Robert Miller, a research biologist at MSI and one of the paper's coauthors. They generally provide the ecosystem's physical structure or main source of food, and as such, have a strong effect on the species that live there.

"The fact that a foundation species, such as giant kelp, could promote the stability of the species for which it provides food and habitat might seem trivial," said lead author Thomas Lamy, a postdoctoral researcher at MSI. "This was part of the original definition of a foundation species -- which dates back to around 1972 -- but had never been tested before."

The researchers pored over 18 years of ecological data from nine shallow reefs in the Santa Barbara Channel. The information included species size and abundance, biodiversity, and biomass, among many other useful data. Statistics and mathematical modeling enabled the scientists to uncover trends and patterns in the data.

The team considered different groups of organisms separately to better understand the ecosystem's dynamics. "It's hard to compare the diversity of, for example, bacteria with the diversity of whales," Miller remarked. For this study, that meant looking at understory algae and invertebrates separately, which revealed nuances that were hidden when the groups were lumped together.

"We found a positive link between the stability of the giant kelp and the stability of understory macroalgae and seafloor invertebrates," said Lamy.

So, giant kelp has a giant effect on the kelp forest. "It can sound rather intuitive," he acknowledged, "but sometimes these are the most difficult ideas to test. As pointed out before, this requires a lot of ecological data."

Fortunately, the researchers had the benefit of nearly two decades of data and observations courtesy of the Santa Barbara Coastal Long-Term Ecological Research Project (SBC LTER). The Marine Science Institute manages the SBC LTER, which is part of a network of sites run by the National Science Foundation.

"That's the advantage of the LTER program: It enables us to look at long-term questions that are critical to ecology," Miller said.

The group found that most of giant kelp's influence on the forest's stability came indirectly. Robust kelp increased species diversity and this in turn increased the ecosystem's stability. In a previous study, the group found that biodiversity alone can bolter stability. If the abundance of different species fluctuates out of sync with each other, their variability tends to even out as a whole, leading to a more stable ecosystem overall. And greater biodiversity means more species contribute to this effect.

"This is what we would expect if giant kelp truly is a foundation species that the whole ecosystem is depending on," Miller said.

Stable kelp forests may harbor more species by promoting steady recruitment, balancing the availability of limiting resources, or providing refuge from different stresses, Lamy suggested. The team plans to investigate these mechanisms in future work.

The relationship between kelp and kelp forests is of particular interest and concern to scientists, who think that the stability of kelp is likely to change in the future. Climate change promises to bring more warming events, larger waves, and stronger storms, all conditions that place pressure on giant kelp. Understanding the relationship between foundation species' stability and ecosystem stability will help us anticipate how the ecosystem will react and then respond accordingly.

Researchers identified two proteins -- mutant tumor protein 53 (mtp53) and poly-ADP-Polymerase (PARP) -- that are present and interacting with DNA during the replication process in patients with triple negative breast cancer.

Suppressing these proteins through a combination of existing PARP-inhibiting therapies could be an effective way to interrupt the development of triple negative breast cancer cells and offer the first targeted treatment for this form of the disease.

The findings may also reclassify triple negative breast cancer as a different form of the disease that can be treated by combining already existing therapies.

NEW YORK, January 29, 2020 (print edition) - A newly published study in the journal Cancer Research (appearing in print on February 1) signals a potential treatment breakthrough for patients with triple negative breast cancer -- a form of the disease that disproportionately affects and also tends to develop more aggressively in black women. The paper, authored by researchers at The Graduate Center of The City University of New York and Hunter College in collaboration with scientists at Memorial Sloan Kettering Cancer Center and the University of Chicago, details findings about the interaction between two specific proteins during DNA replication that appears to drive growth of malignant cells in patients with triple negative breast cancer. The research team found the presence of mtp53 and PARP proteins in a large majority of patients with triple negative breast cancer. Their work suggests the proteins' association and function, and suppressing their interactions could provide a possible target for stopping tumor growth.

"Our new findings suggest that the presence of both mtp53 and PARP could serve as a good identifier of breast cancers that would respond to combined treatment with talazoparib -- a PARP inhibitor that was developed to treat breast cancers with the BRCA mutation -- and temozolomide -- a chemotherapy agent that is used to treat some brain cancers," said Graduate Center and Hunter College Professor Jill Bargonetti, whose lab conducted the research. "This is an exciting finding because it could lead to the first targeted therapy for triple negative breast cancer, enabling more precise and effective treatment of a very aggressive form of the disease."

Researchers investigated a variety of breast cancer cell lines, patient-derived xenographs, tissue microarray samples, and data from The Cancer Genome Atlas to tease out the association and interaction between the mtp53 and PARP proteins in triple negative breast cancer. They discovered that high levels of these proteins are present on replicating DNA in these types of tumors, suggesting that the unusual presence and levels of these proteins may drive tumor growth. Review of the therapeutic mechanism of existing cancer drugs led the research team to identify talazoparib and temozolomide as existing drugs that could potentially be combined to create a targeted therapy that can effectively suppress the growth of triple negative breast cancer tumors.

"Our findings that mutant p53 and PARP participate in the DNA replication pathway will provide mechanism-derived dual biomarkers that aid in the diagnosis and treatment of these therapeutically elusive subsets of breast cancer," said Gu Xiao, a research associate with Bargonetti's lab and the paper's first author.

The team's next step would be to test whether the combined drugs successfully block replication of triple negative breast cancer cells in tumor samples in animal models. If the therapy ultimately proves successful it could lead to the reclassification of the disease to a category of cancers called mutant p53/PARP1 positive cancers, which are treatable by combination PARP inhibitor therapies.

Researchers at the National Institute of Standards and Technology (NIST) and their colleagues have for the first time created and imaged a novel pair of quantum dots -- tiny islands of confined electric charge that act like interacting artificial atoms. Such "coupled" quantum dots could serve as a robust quantum bit, or qubit, the fundamental unit of information for a quantum computer. Moreover, the patterns of electric charge in the island can't be fully explained by current models of quantum physics, offering an opportunity to investigate rich new physical phenomena in materials.

Unlike a classical computer, which relies on binary bits that have just one of two fixed values -- "1" or "0" -- to store memory, a quantum computer would store and process information in qubits, which can simultaneously take on a multitude of values. Therefore, they could perform much larger, more complex operations than classical bits and have the potential to revolutionize computing.

Electrons orbit the center of a single quantum dot similar to the way they orbit atoms. The charged particles can only occupy specific permitted energy levels. At each energy level, an electron can occupy a range of possible positions in the dot, tracing out an orbit whose shape is determined by the rules of quantum theory. A pair of coupled quantum dots can share an electron between them, forming a qubit.

To fabricate the quantum dots, the NIST-led team, which included researchers from the University of Maryland NanoCenter and the National Institute for Materials Science in Japan, used the ultrasharp tip of a scanning tunneling microscope (STM) as if it were a stylus of an Etch A Sketch. Hovering the tip above an ultracold sheet of graphene (a single layer of carbon atoms arranged in a honeycomb pattern), the researchers briefly increased the voltage of the tip.

The electric field generated by the voltage pulse penetrated through the graphene into an underlying layer of boron nitride, where it stripped electrons from atomic impurities in the layer and created a pileup of electric charge. The pileup corralled freely floating electrons in the graphene, confining them to a tiny energy well.

But when the team applied a magnetic field of 4 to 8 tesla (about 400 to 800 times the strength of a small bar magnet), it dramatically altered the shape and distribution of the orbits that the electrons could occupy. Rather than a single well, the electrons now resided within two sets of concentric, closely spaced rings within the original well separated by a small empty shell. The two sets of rings for the electrons now behaved as if they were weakly coupled quantum dots.

This is the first time that researchers have probed the interior of a coupled quantum dot system so deeply, imaging the distribution of electrons with atomic resolution (see illustration), noted NIST co-author Daniel Walkup. To take high-resolution images and spectra of the system, the team took advantage of a special relationship between the size of a quantum dot and the spacing of the energy levels occupied by the orbiting electrons: The smaller the dot, the greater the spacing, and the easier it is to distinguish between adjacent energy levels.

In a previous quantum dot study using graphene, the team applied a smaller magnetic field and found a structure of rings, resembling a wedding cake, centered on a single quantum dot, which is the origin of the concentric quantum dot rings. By using the STM tip to construct dots about half the diameter (100 nanometers) of dots that they had previously studied, the researchers succeeded in revealing the full structure of the coupled system.

The team, which included Walkup, Fereshte Ghahari, Christopher Gutiérrez and Joseph Stroscio at NIST and the Maryland NanoCenter, describes its findings today in Physical Review B.

The way in which the electrons are shared between the two coupled dots can't be explained by accepted models of quantum dot physics, said Walkup. This puzzle may be important to solve if coupled quantum dots are eventually to be used as qubits in quantum computing, Stroscio noted.

Researchers from the Moscow Institute of Physics and Technology have discovered an additional component in ATP synthase, a molecular machine that produces the energy-conserving compound in all cellular organisms. The new unique features of the ATP synthase structure are described in detail in a paper in Scientific Reports.

In order to store energy, living cells rely on a molecule called ATP. It is produced by ATP synthase, a molecular-scale motor comprised by a rotor and a stator. Such machines are nested in the inner membranes of mitochondria and chloroplasts in most organisms, including animals, plants, and bacteria. The rotor component resembles a barrel embedded into a biological membrane. This "barrel," or C-ring, is made of between eight and 17 so-called protomers. Their exact number depends on the organism.

MIPT researchers and their colleagues from Grenoble, France, have obtained a first-ever high-resolution structure of the C ring from spinach chloroplasts. As the 3D computer model of the C ring was taking shape, the biophysicists spotted something peculiar.

"We noticed additional circle-shaped elements inside the C ring," said MIPT doctoral student Alexey Vlasov from the Institute's Research Center for Molecular Mechanisms of Aging and Age-Related Diseases. "At first we thought that was an artifact. But when we looked through the C ring structures obtained by other scientists for various organisms, the circles turned up again, time after time."

It came as a surprise for the researchers that previous studies did not pay attention to the circles inside C rings. Up until now, their nature remained unexplained.

"This study speaks to the fact that no minor detail is negligible in science. Even a subtle feature, spotted in due course, might lead to a breakthrough discovery," noted Valentin Gordeliy, who heads research groups at the Institute of Structural Biology in Grenoble (France) and Jülich Research Center (Germany) and is the scientific coordinator of the MIPT Research Center for Molecular Mechanisms of Aging and Age-Related Diseases.

The biophysicists from MIPT set out to solve the C ring puzzle. Computer modeling and biochemical experiments indicated that the ring contained quinone molecules. They act as electron carriers in biological systems. Some of the examples are plastoquinone, found in chloroplasts, and the coenzyme Q in mitochondria.

Biologists have long known that the C ring of ATP synthase does not have a "hole" in it. So while some molecules were expected to exist on the inside, no one was sure which exactly. The finding proved unexpected: quinones.

While the discovery is interesting in and of itself, researchers have yet to determine why the C ring hosts quinones and how they get there. One theory suggests C rings can function as pores in mitochondrial membranes. Such a pore might open when the cell death process is initiated. Can the quinones in a C ring kill a cell? This is a question for the MIPT biologists to address in their further research.

This release has been removed upon request of the submitter because of a duplicate submission error. The release can be found at: https://www.eurekalert.org/pub_releases/2020-01/nsf-nns012420.php?site_version=e4

January 29, 2020 - In the era of 'Dr. Google,' social media is a tremendous influence on patients interested in cosmetic surgery, and with more than two billion users - representing almost one-third of the internet - YouTube has emerged as an essential platform for reaching people interested in plastic surgery.

However, due to a variety of factors, such as confusing terminology, inaccurate information and unreliable sources, YouTube and social media videos in general aren't necessarily the most reliable source of information, concludes a study in the February issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

The findings come at a time of increasing awareness of the importance of social media in plastic surgery. In a recent ASPS survey, members rated social media as the single greatest impact on people's desire to get or consider getting plastic surgery.

"Anyone can post videos on YouTube, with no regulation or oversight, potentially leading to misinformation," said ASPS member Ash Patel, MBChB, of Albany (N.Y.) Medical Center, senior author of a new study on the accuracy of public-facing plastic surgery videos.

"Patients should be aware that the information contained in aesthetic surgery videos could be of low-quality and has the potential to be inaccurate," Dr. Patel continued. "This study is really about informing the public and encouraging plastic surgeons to play an active role in developing and sharing accurate and more complete videos on cosmetic procedures."

Dr. Patel and colleagues searched YouTube to identify the top results for common aesthetic and plastic surgery procedures. The search included not only the medical terms for the procedures (such as 'abdominoplasty') but also commonly used lay terms (such as 'tummy tuck') and discovered less than ten percent of videos addressed the potential risks, indications, or side effects of cosmetic procedures.

The quality of the information provided by each video was assessed using a modified version of the validated Ensuring Quality Information for Patients (EQIP) tool. The EQIP is used by physicians to determine if medical information is understandable, non-biased and properly describes the risks, benefits and alternatives of medical treatment. Of the total 523 videos rated, about 60 percent were developed by physicians or surgeons, 20 percent by patients, and 20 percent by other sources defined as non-medical personnel and commercial entities promoting services. Physician-produced videos had the highest average number of views compared to the other categories.

Most of the video content was low-quality, with an average EQIP score of about 13, out of a possible 26 points. "Overall, only three out of 21 search terms met criteria for high-quality videos," according to Dr. Patel. "Only the terms 'breast augmentation,' 'eyelid surgery' and 'buttock lift' received high-quality scores--mainly due to the volume of relevant videos produced by so many different plastic surgeons. 'Breast augmentation' had the highest average score (about 16), while 'nose reshaping' had the lowest score (about 10).

Quality was higher for videos developed by physicians or surgeons: average EQIP score of about 14, compared to 12 for videos developed by patients and 10 for videos from other sources. But even for physician-produced videos, only about half of videos were considered high-quality.

"It involves a little research from the viewer, but they should check if the video is produced by a board-certified plastic surgeon" said Dr. Patel. "A good video will be easy to understand and provide information that includes who are good surgical candidates, as well as the risks, benefits and alternatives of the procedure."

PROVIDENCE R.I. [Brown University] -- Researchers from Brown University have designed a new type of wing that could make small fixed-wing drones far more stable and efficient.

The new wing replaces the smooth contour found on the leading edges of most airplane wings with a thick flat plate and a sharp leading edge. Counterintuitive as it may seem, it turns out that the design has distinct aerodynamic advantages at the scale of small drones. In a paper published in Science Robotics, the researchers show that the new wing is far more stable than standard wings in the face of sudden wind gusts and other types of turbulence, which often wreak havoc on small aircraft. The wing also provides an aerodynamically efficient flight that translates into better battery life and longer flight times.

"Small drones can be really useful in many applications, including flights in populated areas as they are inherently safer for humans, but there are problems operating aircraft at those small scales," said Kenny Breuer, a professor in Brown's School of Engineering and the study's senior author. "They tend to be inefficient, which limits the battery-powered flight times of most drones to around 30 minutes or so. They also tend to get blown around by puffs of wind and turbulent air coming from obstacles such as buildings and trees. So we've been thinking about a wing design that might combat those problems."

The idea for a wing that dispenses with the smooth contours of a normal wing's leading edge was inspired by natural flyers like birds and insects. A smooth leading edge helps to keep airflow firmly attached to the wing. But bird and insect wings have usually quite rough and sharp leading edges to promote separation of the airflow. Flow separation causes efficiency problems for large aircraft, but it seems to work just fine for birds and insects.

"Animals at small scale don't try to keep the flow attached," Breuer said. "They gave up on that 100 million years ago. Once you stop trying to keep the flow constantly attached, it ironically makes some things easier."

The new wing -- dubbed the "Separated Flow Airfoil" -- was designed by Matteo Di Luca, a graduate student at Brown and the study's lead author. The idea is to intentionally separate the flow at the leading edge, which somewhat counterintuitively causes the flow to reattach more consistently before reaching the trailing edge. That reattachment is aided by a small rounded flap placed near the wing's trailing edge. The design enables more efficient, more stable flight at the scale of aircraft with wingspans of about a foot or less.

The reason the design works has to do with the characteristics at small scales of the boundary layer, the thin layer of air that's directly in contact with the wing. At the scale of passenger planes, the boundary layer is always turbulent -- full of tiny swirls and vortices. That turbulence holds the boundary layer against the wing, keeping it firmly attached. At small scales, however, the boundary layer tends to be laminar. A laminar boundary layer separates easily from the wing and often never reattaches, which leads to increased drag and reduced lift.

Further complicating matters is the freestream turbulence -- gusts of wind, vortices and other disturbances in the surrounding air. That freestream turbulence can suddenly induce turbulence in a boundary layer, which attaches the flow and induces a sudden jolt of increased lift. Rapid lift fluctuations can be more than a drone's control system can handle, leading to unstable flight.

The Separated Flow wing is able to deal with these issues.

"When we purposefully separate the flow at the leading edge, we cause it to immediately become turbulent, which forces it to reattach at a consistent point regardless of atmospheric turbulence" Di Luca said. "That gives us more consistent lift and overall better performance."

Testing of the Separated Flow Airfoil in a wind tunnel showed that the design successfully smoothed out lift fluctuations associated with freestream turbulence. The team also performed wind tunnel tests of a small propeller-driven drone equipped with the Separated Flow wing. Those tests showed that the increased aerodynamic efficiency resulted in a decreased minimum cruise power compared to standard miniature drones. That translates into extended battery life.

"With the prototype we have, we're at a little less than 3 hours of flight time in the wind tunnel," Di Luca said. "The wind tunnel is an idealized environment, so we don't expect it would last quite that long for an outdoor flight. But if it lasts half as long as it did in the wind tunnel, it's still more than twice the flight of commercially available drones."

There are other benefits to the design in addition to better aerodynamic performance. The Separated Flow wing can be far thicker than wings normally used in small drones. That makes the wings structurally stronger so subsystems like batteries, antennas or solar panels can be integrated into the wing. That could reduce the size of an aerodynamically cumbersome fuselage -- or eliminated the need for one altogether.

The researchers have a patent on their design and plan to continue refining it for even better performance.

WASHINGTON, January 29, 2020 -- Most nuclear data measurements are performed at accelerators large enough to occupy a geologic formation a kilometer wide, like the Los Alamos Neutron Science Center located on a mesa in the desert. But a portable device that can reveal the composition of materials quickly on-site would greatly benefit cases such as in archaeology and nuclear arms treaty verification.

Research published this week in AIP Advances, from AIP Publishing, used computational simulations to show that with the right geometric adjustments, it is possible to perform accurate neutron resonance transmission analysis in a device just 5 meters long.

"We expected massive backgrounds to dilute and contaminate our signal, and early simulation work confirmed that the scale of these effects would make the technique entirely impossible," author Areg Danagoulian said. "However, careful optimization of the geometries allowed us to almost completely suppress these effects, giving us a near-perfect signal."

Using a model of a pulsed deuterium-tritium neutron source in a polycone layout, the researchers performed a series of tests to optimize the moderation, shielding and collimation of the device and probe the configuration for uncertainties introduced by these adjustments. To confirm the device's accuracy, they compared spectral reconstructions and tested the isotopic sensitivity of the device.

"Depending on the goal of the application, one can use spectroscopic radiography to determine the absolute abundances and densities of individual isotopes," Danagoulian said. "It can also be used in treaty verification exercises, where an authentic nuclear weapon component is compared to that from a candidate warhead."

While the tests used silver, tungsten and molybdenum, the method could be used to identify isotopes of plutonium or uranium in nuclear warheads or enriched fuel, as well as tin, silver or gold in archaeological sites. Their work could also be used to similarly reduce the lengths of thermal neutron beamlines.

Their work uses time-of-flight reconstructions of the energies of pulsed neutrons in order to determine the composition of target materials. These reconstructions allow analysis of the spectrum transmitted and nuclear resonances present in different isotopes to identify the isotopic makeup of the material in the target.

Their results show the device was successful. It was able to precisely differentiate various isotopes and was sensitive to variations in isotopic concentrations.

The authors plan to perform experimental validations of the above technique using various pulsed neutrons sources and neutron detectors.

Nearly everyone on Earth is familiar with corn. Literally.

Around the world, each person eats an average of 70 pounds of the grain each year, with even more grown for animal feed and biofuel. And as the global population continues to boom, increasing the amount of food grown on the same amount of land becomes increasingly important.

One potential solution is to develop crops that perform better in cold temperatures. Many people aren’t aware that corn is a tropical plant, which makes it extremely sensitive to cold weather. This trait is problematic in temperate climates where the growing season averages only 4 or 5 months – and where more than 60% of its 1.6 trillion pound annual production occurs.

A chilling-tolerant strain could broaden the latitudes in which the crop could be grown, as well as enable current farmers to increase productivity.

A group of researchers led by David Stern, president of the Boyce Thompson Institute, have taken a step closer to this goal by developing a new type of corn that recovers much more quickly after a cold snap. Stern is also an adjunct professor of plant biology in Cornell University’s College of Agriculture and Life Sciences.

The research is described in a paper published online in Plant Biotechnology Journal on December 20.

This work built on research published in 2018, which showed that increasing levels of an enzyme called Rubisco led to bigger and faster-maturing plants. Rubisco is essential for plants to turn atmospheric carbon dioxide into sugar, and its levels in corn leaves decrease dramatically in cold weather.

In the latest study, Stern and colleagues grew corn plants for three weeks at 25°C (77°F), lowered the temperature to 14°C (57°F) for two weeks, and then increased it back up to 25°C.

“The corn with more Rubisco performed better than regular corn before, during and after chilling,” said Coralie Salesse-Smith, the paper’s first author. “In essence, we were able to reduce the severity of chilling stress and allow for a more rapid recovery.” Salesse-Smith was a Cornell PhD candidate in Stern’s lab during the study, and she is now a postdoctoral researcher at the University of Illinois.

Indeed, compared to regular corn, the engineered corn had higher photosynthesis rates throughout the experiment, and recovered more quickly from the chilling stress with less damage to the molecules that perform the light-dependent reactions of photosynthesis.

The end result was a plant that grew taller and developed mature ears of corn more quickly following a cold spell.

Steve Reiners, a co-team leader for Cornell Cooperative Extension’s vegetable program, says that sweet corn is a major vegetable crop in New York, worth about $40-$60 million annually. He notes that many New York corn growers plant as soon as they can because an early crop commands the highest prices of the season.

Reiners, who was not involved in the study, is also a professor of horticulture at Cornell.

“The corn we developed isn’t yet completely optimized for chilling tolerance, so we are planning the next generation of modifications,” said Stern. “For example, it would be very interesting to add a chilling-tolerant version of a protein called PPDK into the corn and see if it performs even better.”

The researchers believe their approach could also be used in other crops that use the C4 photosynthetic pathway to fix carbon, such as sugar cane and sorghum.

UPTON, NY--Plants take in energy from sunlight to transform atmospheric carbon dioxide (CO2) into sugars and then other materials for growth and metabolic functions. Mimicking this photochemical reaction to efficiently convert CO2 into fuels and industrially important chemicals would support a sustainable energy future and reduce greenhouse gas emissions.

To realize such artificial photosynthesis, scientists have been studying catalytic systems composed of multiple components that work together to drive the transfer of photo-induced electrons required to convert CO2 into energy-rich products. One such product is formate, a salt form of formic acid--a naturally occurring organic chemical made of hydrogen and CO2 molecules. The production of formate from CO2 is considered an attractive strategy for the long-term storage of solar renewable energy in chemical form.

Multicomponent CO2 conversion systems typically include a photosensitizer, a catalyst, and a sacrificial electron donor in solution. Upon absorbing light, the photosensitizer jumps to an excited state, where it accepts electrons from the donor. The catalyst--whose function is to minimize the high energy barrier to activate CO2, a very stable molecule--then uses these high-energy electrons to complete a series of reactions.

For many studies on photochemical CO2 conversion using molecular catalysts, such as those based on ruthenium and other metal complexes, triethanolamine (TEOA) is the component donating the electrons. Or, in some cases, TEOA is accepting a proton (positively charged hydrogen ion) from a more efficient electron donor to ensure its sacrificial behavior. Despite the wide use of TEOA, much of the research to date has not considered the possibility of this component playing secondary roles, such as changing the temporary chemical species (intermediates) generated within the catalytic cycle or increasing the reaction rates.

A team of chemists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and the City University of New York's Baruch College set out to change that.

"For the last 40 years, most studies on CO2 reduction catalysts have focused on analyzing catalytic efficiency and selectivity for the final product," said Renato Sampaio, a research associate in the Artificial Photosynthesis Group of Brookhaven Lab's Chemistry Division. "However, it is important to know if and how TEOA interacts with the catalyst during intermediate steps of the catalytic cycle because these interactions may decisively influence the efficiency and selectivity of product formation."

Focusing on a well-known catalytic system in an acetonitrile solution consisting of a ruthenium carbonyl (carbon atom bonded to oxygen atom) catalyst, a ruthenium-based photosensitizer, a common electron donor known as BIH, and TEOA acting as a proton acceptor to promote the sacrificial behavior of BIH, the chemists made some surprising discoveries. As they reported in a paper published online on Dec. 27 in the Journal of the American Chemical Society, TEOA fails at its primary intended task of efficiently accepting protons from BIH, thus limiting catalytic activity. However, TEOA enhances key steps of the catalytic cycle for the conversion of CO2 to formate, the target product.

For example, TEOA acts as a proton source supporting the formation of a metal hydride (ruthenium attached to hydrogen) that subsequently interacts with CO2 to make bound formate (bound to ruthenium). Moreover, TEOA interacts with CO2 to form a "zwitterionic adduct," a molecule containing both positive and negative electrical charges. When this adduct is present in solution, the metal hydride interacts with CO2 to make bound formate at a rate that is six orders of magnitude faster than that without TEOA. The dissociation of bound formate into "free" formate--which can be captured as the final product--is also six orders of magnitude faster because of TEOA.

To make these determinations, the team collected both electrochemical and spectroscopic data.

"The catalytic cycle can generate a large number of reaction intermediates," explained co-corresponding author Etsuko Fujita, leader of the Artificial Photosynthesis Group. "The challenge is characterizing them by spectroscopic or electrochemical techniques."

First, the team measured the reduction potentials of the catalyst (how easily the catalyst gains an electron) in the presence and absence of TEOA. Then, they characterized the spectroscopic vibrations of the carbonyl for different forms of the catalyst before and after it receives an electron. Following these electrochemistry measurements, they conducted time-resolved infrared spectroscopy experiments on nanosecond timescales to monitor the catalytic intermediates in a CO2 atmosphere.

"The carbonyl that is bound to ruthenium enabled us to study each transient intermediate form of the catalyst," explained Sampaio. "The carbonyl is a very sensitive infrared spectroscopic reporter that remains bound to ruthenium throughout the catalytic cycle, unlike other parts of the catalyst. Its vibrational frequency, or atomic motion, dramatically shifts as the catalyst accepts an electron or undergoes other structural changes. We can detect these shifts and view them alongside the electrochemistry measurements to tell which species are present."

In future studies, the team will explore alternatives to TEOA that maximize the sacrificial ability of BIH while offering similar advantages in enhancing the catalytic cycle.

"Even though our study focused on a specific class of catalysts, we strongly believe that our findings are broadly applicable across other systems and should be taken into consideration when investigating the catalytic reduction of CO2 to formate," said Fujita.

A team of scientists has observed, for the first time, the presence of warm water at a vital point underneath a glacier in Antarctica--an alarming discovery that points to the cause behind the gradual melting of this ice shelf while also raising concerns about sea-level rise around the globe.

"Warm waters in this part of the world, as remote as they may seem, should serve as a warning to all of us about the potential dire changes to the planet brought about by climate change," explains David Holland, director of New York University's Environmental Fluid Dynamics Laboratory and NYU Abu Dhabi's Center for Global Sea Level Change, which conducted the research. "If these waters are causing glacier melt in Antarctica, resulting changes in sea level would be felt in more inhabited parts of the world."

The recorded warm waters--more than two degrees above freezing--flow beneath the Thwaites Glacier, which is part of the Western Antarctic Ice Sheet. The discovery was made at the glacier's grounding zone--the place at which the ice transitions between resting fully on bedrock and floating on the ocean as an ice shelf and which is key to the overall rate of retreat of a glacier.

Thwaites' demise alone could have significant impact globally.

It would drain a mass of water that is roughly the size of Great Britain or the state of Florida and currently accounts for approximately 4 percent of global sea-level rise. Some scientists see Thwaites as the most vulnerable and most significant glacier in the world in terms of future global sea-level rise--its collapse would raise global sea levels by nearly one meter, perhaps overwhelming existing populated areas.

While the glacier's recession has been observed over the past decade, the causes behind this change had previously not been determined.

"The fact that such warm water was just now recorded by our team along a section of Thwaites grounding zone where we have known the glacier is melting suggests that it may be undergoing an unstoppable retreat that has huge implications for global sea level rise," notes Holland, a professor at NYU's Courant Institute of Mathematical Sciences.

The scientists' measurements were made in early January, after the research team created a 600-meter deep and 35-centimeter wide access hole and deployed an ocean-sensing device to measure the waters moving below the glacier's surface. This device gauges the turbulence of the water as well as other properties such as temperature. The result of turbulence is the mixing of fresh meltwater from the glacier and salty water from the ocean.

It marks the first time that ocean activity beneath the Thwaites Glacier has been accessed through a bore hole and that a scientific instrument measuring underlying ocean turbulence and mixing has been deployed. The hole was opened on January 8 and 9 and the waters beneath the glacier measured January 10 and 11.

Aurora Basinski, an NYU graduate student who made the turbulence measurement, said, "From our observations into the ocean cavity at the grounding zone we observed not only the presence of warm water, but also its turbulence level and thus its efficiency to melt the ice shelf base."

Another researcher, Keith Nicholls, a scientist with the British Antarctic Survey, added, "This is an important result as this is the first time turbulent dissipation measurements have been made in the critical grounding zone of the West Antarctic Ice Sheet."

FINDINGS

The study reveals a detailed epigenetic mechanism for how interleukin-1-beta, a common cytokine that helps fight infections during inflammation, plays a critical role in cancer metastasis. The researchers found that chronic exposure to interleukin-1-beta can promote lung cancer metastasis through inheritable changes of gene expression without altering DNA sequence. Because of these gene alterations, cancer cells can memorize this phenotype -- known as epithelial-to-mesenchymal transition, an important step during cancer metastasis -- to successfully reach distance organs and subsequently colonize.

BACKGROUND

Lung cancer remains the most lethal cancer type in the United States. The vast majority of people with lung cancer die from tumor reoccurrence or metastasis. Therefore, one of the biggest challenges in treating cancer is stopping it from metastasizing to other parts of the body. Scientists have known that chronic inflammation facilities tumor progression, but how this process leads to the spread of cancer is not well elucidated. Previous research has showed interleukin-1-beta is correlated with poor survival in people with non-small cell lung cancer and exposure of this cytokine prompts the expression of genes that are often involved in invasion during metastasis in multiple cancers. The UCLA team enhanced the understanding of the process by studying the role of chronic interleukin-1-beta exposure in the epithelial-to-mesenchymal transition.

METHOD

The researchers investigated the role of interleukin-1-beta in lung cancer metastasis by looking at in vitro models of lung cancer to help provide insight into the cells' behaviors. They specifically examined whether interleukin-1-beta induced epithelial-to-mesenchymal transition in lung cancer cells. The team detailed the mechanism by analyzing the different cell lines to see if there were cellular signaling and protein interactions that would lead to the epithelial-to-mesenchymal transition phenotype. About 30% of the cell lines showed signaling of the memory phenotype, confirming that the mechanism is one of pathways that promote cancer metastasis.

IMPACT

The study furthers researchers' understanding of the role of interleukin-1-beta-induced chronic inflammation in tumor progressions and metastasis, which can potentially contribute to the improvement of both the prevention and treatment of lung cancer.

A new study has revealed how the gut's protective mechanisms ramp up significantly with food intake, and at times of the day when mealtimes are anticipated based on regular eating habits.

Researchers from the Walter and Eliza Hall Institute found, in laboratory models, that eating sets off a hormonal 'chain reaction' in the gut.

Eating causes a hormone called VIP to kickstart the activity of immune cells in response to potentially incoming pathogens or 'bad' bacteria. The researchers also found that immunity increased at anticipated mealtimes indicating that maintaining regular eating patterns could be more important than previously thought.

With the rise in conditions associated with chronic inflammation in the gut, such as irritable bowel and Crohn's disease, a better understanding of the early protective mechanisms governing gut health could help researchers to develop prevention strategies against unwanted inflammation and disease.

The research, led by Professor Gabrielle Belz and Dr Cyril Seillet from the Walter and Eliza Hall Institute, was published in the journal Nature Immunology.

At a glance

Eating activates immune cells in the gut that protect against pathogens and preserve gut health.

Immunity in the gut also ramps up at regular mealtimes in anticipation of eating and a potentially increased risk of infection.

Understanding the complex interactions between eating, gut health and inflammation could aid in the development of prevention and treatment strategies for chronic inflammatory diseases.

Armed against invaders

So how does it work?

When food is consumed nerves in the intestine produce a hormone called vasoactive intestinal peptide (VIP) to 'switch on' a protective response in the gut.

Professor Belz said the team showed, for the first time, that food-induced activation of VIP in preclinical models was vital for a subset of immune cells called ILC3s to mount a protective response in the gut.

"Food intake 'switches on' VIP, which plays a critical role in alerting the gut's army of ILC3 immune cells. In response, ILC3s secrete interleukin-22 (IL-22), which swings into protective action to defend against pathogens and maintain tissue integrity.

"We also showed that a deficiency in VIP limits the production of IL-22, which in turn negatively impacts the immune system's ability to prevent unwanted inflammation," she said.

The researchers used advanced imaging techniques to identify the 'players' integral to protective immunity in the gut. Using a new imaging technique that makes tissue translucent, the researchers were able to capture high-resolution, 3D images of how VIP and ILC3 immune cells interact to protect the gut. Results showed their close proximity which confirmed their interdependence.

Regular meals key to gut health

The researchers also showed that 'circadian clock' genes could enable the gut to ramp up immunity in anticipation of regular mealtimes.

Dr Seillet said baseline gut immunity fluctuated throughout the day, based on circadian rhythms and an anticipatory response to regular eating patterns.

"We saw that gut immunity not only spikes with food intake. It also rises and falls due to inbuilt cellular machinery regulated by the circadian clock gene Bmal1, which appears to activate immune cells when eating is likely," Dr Seillet said.

"While more work needs to be done to better understand this anticipatory mechanism, the results are very interesting and could help to explain why disruptions to circadian rhythms and regular eating patterns could increase chronic inflammation in the gut."

Protective effect

Dr Seillet said a detailed knowledge about mechanisms for gut protection and tissue repair could be useful for preventing against early-stage gut inflammation, before full-blown disease occurred.

"The next steps of our research include gaining a molecular understanding of what properties of food are responsible for kickstarting the process of protective immunity," he said.

"For example, are there certain diets that drive a more protective response than others?"

The study was supported by the Victorian Government and the Australian National Health and Medical Research Council.

CATONSVILLE, MD, January 29, 2020 - Consumers want what they want, and they want it now. Drone delivery has long been talked about as an option to satisfy consumer delivery demands, but how realistic is it? New research in the INFORMS journal Transportation Science looks at how possible and desirable it is to use drones for delivery for e-retailers considering cost and effectiveness in certain population areas and in certain locations.

The study, conducted by Gohram Baloch and Fatma Gzara, both of the University of Waterloo in Ontario, Canada, uses New York City as an example and looks at data surrounding the Manhattan area. The authors separated the area into boroughs based on population and size.

Baloch and Gzara said they chose New York because the world's largest e-retail company, Amazon, first started its 2-hour delivery services in the Big Apple.

"We analyze the tradeoffs between distribution costs and revenues under varying social difficulties with drones like customer preferences and regulatory and technological limitations. We then can make educated decisions on how many facilities to open, which services to offer at that facility and which services to make available to customers in certain areas," said Gzara, a professor in the Department of Management Sciences at Waterloo.

The optimal design for the test locations in New York City, based on all factors, is three drone facilities covering 75% of the New York City area and 34% of the population. Opening a fourth facility increases area and population coverage to 84% and 38%, respectively, but the increase in operation cost is not enough to cover the facility costs.

The modeling and analysis can be used by e-retailers to analyze the economic desirability of offering a drone package delivery and its effect on their network. Regulatory bodies can use the work to test the impact of regulations on potential adaptation of drone deliveries by the e-retail industry.

"Our results show that government regulations, technological limitations, and service charge decisions play a vital role in optimal configurations and drone target markets," continued Gzara. "Under current drone landing capabilities, a drone delivery service may not be possible in a densely populated area like Manhattan where demand for such a service is expected to be high."

Baloch and Gzara said under the right technological capabilities and regulations, e-retailers can reach smaller markets and more price sensitive customers by possibly offering discounts on drone delivered orders.

Tiny meteorites no larger than grains of sand hold new clues about the atmosphere on ancient Earth, according to scientists.

Iron micrometeorites found in ancient soils suggest carbon dioxide made up 25 to 50 percent of Earth's atmosphere 2.7 billion years ago, and that pressure at sea level may have been lower than today, Penn State researchers said.

The meteorites melted as they streaked through the atmosphere and oxidized as they encountered atmospheric gases. Evidence of the oxidation remains on the tiny fragments that landed on Earth. The samples serve as a unique proxy for conditions in the upper atmosphere, the scientists said.

"This is a promising new tool for figuring out the composition of the upper atmosphere billions of years in the past," said Rebecca Payne, a doctoral candidate in geosciences and astrobiology at Penn State. Payne is lead author of the study, published recently in the journal Proceedings of the National Academy of Sciences.

The work builds on previous studies of the micrometeorites that suggested free oxygen molecules in the upper atmosphere oxidized the meteorites. Those findings would require oxygen levels on ancient Earth to be near modern day levels, a surprising conclusion that contradicts conditions expected on the young planet, Payne said.

The researchers conducted a new analysis using photochemical and climate models and determined carbon dioxide, not oxygen, likely served as the main oxidant. For this to be possible, they found carbon dioxide had to comprise at least 25 percent of the atmosphere.

Those levels of carbon dioxide would suggest a warm planet, but other climate evidence finds Earth was cool at the time and partly covered by glaciers. Lower nitrogen levels resulting in lower pressure would allow for both high carbon dioxide levels and cool conditions.

"There are data, referenced in our paper, that support lower nitrogen concentrations during this time," said Jim Kasting, Evan Pugh University Professor in the Department of Geosciences at Penn State and Payne's adviser. "Our study of micrometeorite oxidation falls in line with that interpretation. The possibility that our major atmospheric gas, nitrogen, was less abundant in the distant past is really intriguing."

The findings may help reconcile disagreements in previous studies on carbon dioxide in the deep past and climate model estimates, according to the researchers.

Previous estimates of carbon dioxide levels from billions of years ago rely on paleosols, or ancient soils, which may better reflect conditions in the lower atmosphere. Regional differences like weather or ground cover also can impact paleosols samples, and the findings from these studies often contradict each other and climate models, the scientists said.

"It was getting difficult to figure out where the agreement should have been between different paleosol studies and climate models," Payne said. "This is interesting, because it's a new point of comparison. It may help us find the right answer about atmospheric carbon dioxide in the deep past."