Earth

Irvine, Calif., March 14, 2018 -- Using data from NASA missions observing Earth, researchers at the University of California, Irvine have created new maps of the bed topography beneath a score of glaciers in southeast Greenland, thereby gaining a much better understanding of why some are undergoing rapid retreat and others are relatively stable.

"The undersides of glaciers in deeper valleys are exposed to warm, salty Atlantic water, while the others are perched on sills, protected from direct exposure to warmer ocean water," said Romain Millan, lead author of the study, available online in the American Geophysical Union journal Geophysical Research Letters. "We have been able to demonstrate unequivocally that glacier retreat in southeast Greenland is controlled by the topography of the bedrock under the ice and by ocean temperature."

Millan, a UCI graduate student researcher in Earth system science, and his colleagues analyzed 20 major outlet glaciers in southeast Greenland using high-resolution airborne gravity measurements and ice thickness data from NASA's Operation IceBridge mission; bathymetry information from NASA's Oceans Melting Greenland project; and results from the BedMachine version 3 computer model, developed at UCI.

They found glacial fjords hundreds of meters deeper than previously estimated; the full extent of the marine-based portions of the glaciers; deep troughs enabling Atlantic Ocean water to reach the glacier fronts and melt them from below; and few shallow sills that limit contact with this warmer water.

"It's important to understand the physical processes controlling the retreat in order to improve projections of sea level rise from this region in a warming climate," Millan said. "Until recently, we had little information on ocean temperature and water depth in these fjords to quantify these processes, so the interpretation of glacier evolution on a case-by-case basis was difficult."

Co-author Eric Rignot, UCI professor of Earth system science, added, "Now that the picture is clear, the role of the ocean in glacier evolution is overwhelming."

Rignot, who has led dozens of research expeditions to Earth's polar regions, said that southeast Greenland - with its fast-moving glaciers, deep fjords and harsh climate conditions - poses significant challenges to researchers.

"Thanks to the newest NASA missions, such as Oceans Melting Greenland and Operation IceBridge, we have been able to make great advances in understanding the evolution of this very dynamic sector of Greenland and its impact on sea level rise now and in decades to come," he said.

Species living in coastal regions could face a significant future threat from reduced levels of oxygen in the marine environment, according to research published in Scientific Reports.

The prevalence of hypoxic (low oxygen) areas in coastal waters is predicted to increase in the future, both in terms of their scale and duration. And while the adults of many estuarine invertebrates can cope with short periods of hypoxia, it has previously been unclear whether that ability is present if animals are bred and reared under chronic hypoxia.

A study by the University of Plymouth showed that exposure to even moderate hypoxia can have markedly different effects on metabolic performance, depending on whether adults are exposed to short-term hypoxia or undergo the whole of their development under hypoxic conditions.

Scientists warn that these differing reactions could result in the number of vulnerable species in an affected region currently being underestimated, and ultimately lead to vastly reduced biodiversity in ways that are not immediately obvious.

Lecturer in Marine Molecular Biology Dr Manuela Truebano and Professor in Marine Zoology John Spicer, from the University's Marine Biology and Ecology Research Centre, led the study with contribution from students from the Marine Biology programmes.

Dr Truebano said: "Along with ocean acidification and rising temperatures, hypoxia is considered one of the main threats to species within the marine environment - but it is currently the least talked about. As the duration and extent of hypoxic areas is predicted to increase in coastal regions, it is likely that some species will be exposed chronically throughout their life cycle. Most studies to date focus on short term responses observed in adults and, based on these, many estuarine species are currently considered hypoxia-tolerant.

"We observed a detrimental effect of hypoxia in animals reared under low oxygen, not apparent from observations in short term studies in adults. We believe hypoxia will have marked effects on some aquatic invertebrates currently thought of as hypoxia tolerant, based largely on their ability to do well during exposure to periodic hypoxia."

For the study, scientists focused on the brackishwater (Gammarus chevreuxi), which as an amphipod is a ubiquitous and ecologically important group found throughout the marine environment from the poles to the tropics.

They exposed both adults and young to the reduced levels of oxygen typically and periodically found in coastal regions for one week and monitored their varying response.

Adults collected from the wild and tested under laboratory conditions maintained their levels of oxygen uptake when exposed to moderate hypoxia for one week.

However, the offspring of these adults, when reared in hypoxic conditions showed less ability to regulate their oxygen uptake and were significantly smaller than those of normoxic parents, potentially because they were having to expend more energy simply to survive in those conditions.

From this the scientists deduced that short-term acclimation ability observed in adults after one week does not predict the ability of their offspring to cope with low oxygen, if reared under moderate hypoxia.

Dr Truebano added: "The observation that these small and seemingly insignificant estuarine animals, reared in hypoxic conditions, become physiologically compromised as adults is a cause of concern for this species. But as a vital part of the food chain, there could be significant knock-on effects for other species as well. Importantly, our study suggests that, by focusing research exclusively on adults, it is likely that we will underestimate the number of species vulnerable to decreasing levels of oxygen in the marine environment."

CHICAGO - An innovative use for a known drug is showing promise as an effective treatment for preventing postoperative nausea and vomiting (PONV), suggests a study published today in the Online First edition of Anesthesiology, the peer-reviewed medical journal of the American Society of Anesthesiologists (ASA). The drug, amisulpride, showed a statistically significant reduction in the occurrence of PONV, when used intraoperatively in combination with a standard anti-nausea treatment, in the 24 hours after surgery in high risk patients.

"Tens of millions of Americans undergo surgery each year and many suffer with nausea and vomiting after their operation," said lead researcher Peter Kranke, M.D., professor of anesthesiology at the University of Würzburg in Germany. "Post-operative nausea and vomiting contributes to patient distress, can delay recovery after surgery and increases hospital costs. Patients with multiple risk factors for PONV require a multimodal approach for its prevention, including using a combination of anti-nausea drugs with different mechanisms of action, since it cannot be predicted which pathway(s) will be active in a patient."

Risk factors for PONV include being female, having a prior history of PONV or motion sickness, nonsmokers and those expected to use opioids after surgery for pain. Without effective preventive treatment, nausea and/or vomiting in the 24 hours after surgery may occur in 60 to 80 percent of patients with at least three of the recognized risk factors.

Currently, drugs from the serotonin 5-HT3 and corticosteroid classes are most commonly administered intraoperatively to prevent nausea and vomiting after surgery. However, "safe and effective anti-nausea drugs from other classes are needed to complement these," Dr. Kranke said.

Amisulpride works by blocking dopamine signaling in the body. Similar dopamine-blocking drugs were once previously used to prevent and control nausea and vomiting after surgery but are now avoided because irregular heart rhythms and drug-induced movement disorders occurred with their use. Amisulpride appears to be as effective as the previously used drugs in that class, but without the safety concerns, the authors note.

The study included 1,147 adult patients undergoing elective surgery under general anesthesia, who had three or four PONV risk factors. Patients were randomly assigned to receive either 5 milligrams of amisulpride intravenously or a placebo at the beginning of receiving general anesthesia, in addition to another anti-nausea drug.

Researchers found 58 percent of patients receiving amisulpride had a complete response -- defined as no vomiting or need for fast-acting medication to relieve vomiting -- in the 24 hours after surgery, compared with 47 percent of those receiving the placebo. Overall, vomiting (14 percent amisulpride vs. 20 percent placebo), any nausea (50 percent amisulpride vs. 58 percent placebo), significant nausea (37 percent amisulpride vs. 48 percent placebo), and those requiring fast-acting medication to relieve vomiting (41 percent amisulpride vs. 49 percent placebo) were significantly lower in the amisulpride group. Adverse events occurred no more frequently with amisulpride than with placebo.

The researchers concluded a low dose of intravenous amisulpride is safe and effective in preventing PONV when given in combination with an anti-nausea drug from another class to high-risk adult patients undergoing elective procedures. "This could enable improved control of PONV and allow for earlier mobilization and discharge of surgical patients," Dr. Kranke said.

Amisulpride is currently under review by the U.S. Food and Drug Administration. According to the authors, amisulpride has been used orally - in much larger doses than the intravenous dose used to prevent PONV in the current study - in European patients for 30 years to manage psychosis.

Notanee Bourassa knew that what he was seeing in the night sky was not normal. Bourassa, an IT technician in Regina, Canada, trekked outside of his home on July 25, 2016, around midnight with his two younger children to show them a beautiful moving light display in the sky -- an aurora borealis. He often sky gazes until the early hours of the morning to photograph the aurora with his Nikon camera, but this was his first expedition with his children. When a thin purple ribbon of light appeared and starting glowing, Bourassa immediately snapped pictures until the light particles disappeared 20 minutes later. Having watched the northern lights for almost 30 years since he was a teenager, he knew this wasn't an aurora. It was something else.

From 2015 to 2016, citizen scientists -- people like Bourassa who are excited about a science field but don't necessarily have a formal educational background -- shared 30 reports of these mysterious lights in online forums and with a team of scientists that run a project called Aurorasaurus. The citizen science project, funded by NASA and the National Science Foundation, tracks the aurora borealis through user-submitted reports and tweets.

The Aurorasaurus team, led by Liz MacDonald, a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, conferred to determine the identity of this mysterious phenomenon. MacDonald and her colleague Eric Donovan at the University of Calgary in Canada talked with the main contributors of these images, amateur photographers in a Facebook group called Alberta Aurora Chasers, which included Bourassa and lead administrator Chris Ratzlaff. Ratzlaff gave the phenomenon a fun, new name, Steve, and it stuck.

But people still didn't know what it was.

Scientists' understanding of Steve changed that night Bourassa snapped his pictures. Bourassa wasn't the only one observing Steve. Ground-based cameras called all-sky cameras, run by the University of Calgary and University of California, Berkeley, took pictures of large areas of the sky and captured Steve and the auroral display far to the north. From space, ESA's (the European Space Agency) Swarm satellite just happened to be passing over the exact area at the same time and documented Steve.

For the first time, scientists had ground and satellite views of Steve. Scientists have now learned, despite its ordinary name, that Steve may be an extraordinary puzzle piece in painting a better picture of how Earth's magnetic fields function and interact with charged particles in space. The findings are published in a study released today in Science Advances.

"This is a light display that we can observe over thousands of kilometers from the ground," said MacDonald. "It corresponds to something happening way out in space. Gathering more data points on STEVE will help us understand more about its behavior and its influence on space weather."

The study highlights one key quality of Steve: Steve is not a normal aurora. Auroras occur globally in an oval shape, last hours and appear primarily in greens, blues and reds. Citizen science reports showed Steve is purple with a green picket fence structure that waves. It is a line with a beginning and end. People have observed Steve for 20 minutes to 1 hour before it disappears.

If anything, auroras and Steve are different flavors of an ice cream, said MacDonald. They are both created in generally the same way: Charged particles from the Sun interact with Earth's magnetic field lines.

The uniqueness of Steve is in the details. While Steve goes through the same large-scale creation process as an aurora, it travels along different magnetic field lines than the aurora. All-sky cameras showed that Steve appears at much lower latitudes. That means the charged particles that create Steve connect to magnetic field lines that are closer to Earth's equator, hence why Steve is often seen in southern Canada.

Perhaps the biggest surprise about Steve appeared in the satellite data. The data showed that Steve comprises a fast moving stream of extremely hot particles called a sub auroral ion drift, or SAID. Scientists have studied SAIDs since the 1970s but never knew there was an accompanying visual effect. The Swarm satellite recorded information on the charged particles' speeds and temperatures, but does not have an imager aboard.

"People have studied a lot of SAIDs, but we never knew it had a visible light. Now our cameras are sensitive enough to pick it up and people's eyes and intellect were critical in noticing its importance," said Donovan, a co-author of the study. Donovan led the all-sky camera network and his Calgary colleagues lead the electric field instruments on the Swarm satellite.

Steve is an important discovery because of its location in the sub auroral zone, an area of lower latitude than where most auroras appear that is not well researched. For one, with this discovery, scientists now know there are unknown chemical processes taking place in the sub auroral zone that can lead to this light emission.

Second, Steve consistently appears in the presence of auroras, which usually occur at a higher latitude area called the auroral zone. That means there is something happening in near-Earth space that leads to both an aurora and Steve. Steve might be the only visual clue that exists to show a chemical or physical connection between the higher latitude auroral zone and lower latitude sub auroral zone, said MacDonald.

"Steve can help us understand how the chemical and physical processes in Earth's upper atmosphere can sometimes have local noticeable effects in lower parts of Earth's atmosphere," said MacDonald. "This provides good insight on how Earth's system works as a whole."

The team can learn a lot about Steve with additional ground and satellite reports, but recording Steve from the ground and space simultaneously is a rare occurrence. Each Swarm satellite orbits Earth every 90 minutes and Steve only lasts up to an hour in a specific area. If the satellite misses Steve as it circles Earth, Steve will probably be gone by the time that same satellite crosses the spot again.

In the end, capturing Steve becomes a game of perseverance and probability.

"It is my hope that with our timely reporting of sightings, researchers can study the data so we can together unravel the mystery of Steve's origin, creation, physics and sporadic nature," said Bourassa. "This is exciting because the more I learn about it, the more questions I have."

As for the name "Steve" given by the citizen scientists? The team is keeping it as an homage to its initial name and discoverers. But now it is STEVE, short for Strong Thermal Emission Velocity Enhancement.

A new study has re-discovered fossil collections from a 19th century hermit that validate 'phantom' fossil footprints collected in the 1950s showing dicynodonts coexisting with dinosaurs.

A video about this new research can be found here: https://youtu.be/BrdwIQKPCHY

Before the dinosaurs, around 260 million years ago, a group of early mammal relatives called dicynodonts were the most abundant vertebrate land animals. These bizarre plant-eaters with tusks and turtle-like beaks were thought to have gone extinct by the Late Triassic Period, 210 million years ago, when dinosaurs first started to proliferate. However, in the 1950s, suspiciously dicynodont-like footprints were found alongside dinosaur prints in southern Africa, suggesting the presence of a late-surviving phantom dicynodont unknown in the skeletal record. These "phantom" prints were so out-of-place that they were disregarded as evidence for dicynodont survival by paleontologists. A new study has re-discovered fossil collections from a 19th century hermit that validate these "phantom" prints and show that dicynodonts coexisted with early plant-eating dinosaurs. While this research enhances our knowledge of ancient ecosystems, it also emphasizes the often-overlooked importance of trace fossils, like footprints, and the work of amateur scientists.

"Although we tend to think of paleontological discoveries coming from new field work, many of our most important conclusions come from specimens already in museums," says Dr. Christian Kammerer, Research Curator of Paleontology at the North Carolina Museum of Natural Sciences and author of the new study.

The re-discovered fossils that solved this mystery were originally collected in South Africa in the 1870s by Alfred "Gogga" Brown. Brown was an amateur paleontologist and hermit who spent years trying, with little success, to interest European researchers in his discoveries. Brown had shipped these specimens to the Natural History Museum in Vienna in 1876, where they were deposited in the museum's collection but never described.

"I knew the Brown collections in Vienna were largely unstudied, but there was general agreement that his Late Triassic collections were made up only of dinosaur fossils. To my great surprise, I immediately noticed clear dicynodont jaw and arm bones among these supposed 'dinosaur' fossils," says Kammerer. "As I went through this collection I found more and more bones matching a dicynodont instead of a dinosaur, representing parts of the skull, limbs, and spinal column." This was exciting--despite over a century of extensive collection, no skeletal evidence of a dicynodont had ever been recognized in the Late Triassic of South Africa.

Before this point, the only evidence of dicynodonts in the southern African Late Triassic was from questionable footprints: a short-toed, five-fingered track named Pentasauropus incredibilis (meaning the "incredible five-toed lizard foot"). In recognition of the importance of these tracks for suggesting the existence of Late Triassic dicynodonts and the contributions of "Gogga" Brown in collecting the actual fossil bones, the re-discovered and newly described dicynodont has been named Pentasaurus goggai ("Gogga's five-[toed] lizard").

"The case of Pentasaurus illustrates the importance of various underappreciated sources of data in understanding prehistory," says Kammerer. "You have the contributions of amateur researchers like 'Gogga' Brown, who was largely ignored in his 19th century heyday, the evidence from footprints, which some paleontologists disbelieved because they conflicted with the skeletal evidence, and of course the importance of well-curated museum collections that provide scientists today an opportunity to study specimens collected 140 years ago."

Around one in four elderly Japanese women will live below the poverty level in the near future -- with the figure rising to 50% for never-married and divorced women. In contrast, only about 10% of Japanese men will become impoverished. This is the prediction of a new model of current Japanese pension system, published today in Frontiers in Physics, that investigates how and why elderly women in the country will enter poverty.

"The advent of a super-aged society is forecast for Japan in the near future, and impoverishment of people is our main concern," says Seiichi Inagaki, author of the study and a researcher at the International University of Health and Welfare in Japan.

"It is considered that many elderly women will face a poverty problem, however, there is no future estimate on poverty rates that shows how and why elderly women will enter poverty. This study provides the future estimates that answer these questions."

The current pension system in Japan was designed more than half a century ago for post-war families. In those times, women typically quit their jobs to have children and become housewives, and the pension system was relatively generous for women in these circumstances.

Since then, however, women have increasingly chosen not to marry, or else are divorced. Under the current pension system such women receive only a fraction of the pension calculated for married women -- and these payments will not be sufficient to keep these women above poverty levels.

Inagaki provides detailed predictions on these worrying trends using a dynamic microsimulation pension model called the Integrated Analytical Model for Household Simulation (INAHSIM). Such models are a commonly used tool to predict the future financial outcomes of pension systems for individual groups of people within a system, although the simulation is limited to public benefits and does not incorporate other financial assets.

"This study illustrates how the poverty rate will increase in the future," says Inagaki. "In the end, many never-married or divorced women will be living in poverty in their old age due to the unfavorable public pension system and their higher risk of living in a single-person household. This will raise the overall poverty rate."

These simulations indicate that roughly 50% of never-married or divorced women will become impoverished in the next 50 years, compared to only 10 to 20% of widows or married women. Overall, the study forecasts that nearly 25% of elderly Japanese women will be impoverished, in contrast with only about 10% of Japanese men.

"These results imply that the current social security system will not work well for these women," says Inagaki. "I hope that the government will consider reform of the social security system and take appropriate measures for these women."

CAMBRIDGE, MA -- MIT engineers have developed new technology that could be used to evaluate new drugs and detect possible side effects before the drugs are tested in humans. Using a microfluidic platform that connects engineered tissues from up to 10 organs, the researchers can accurately replicate human organ interactions for weeks at a time, allowing them to measure the effects of drugs on different parts of the body.

Such a system could reveal, for example, whether a drug that is intended to treat one organ will have adverse effects on another.

"Some of these effects are really hard to predict from animal models because the situations that lead to them are idiosyncratic," says Linda Griffith, the School of Engineering Professor of Teaching Innovation, a professor of biological engineering and mechanical engineering, and one of the senior authors of the study. "With our chip, you can distribute a drug and then look for the effects on other tissues and measure the exposure and how it is metabolized."

These chips could also be used to evaluate antibody drugs and other immunotherapies, which are difficult to test thoroughly in animals because they are designed to interact with the human immune system.

David Trumper, an MIT professor of mechanical engineering, and Murat Cirit, a research scientist in the Department of Biological Engineering, are also senior authors of the paper, which appears in the journal Scientific Reports. The paper's lead authors are former MIT postdocs Collin Edington and Wen Li Kelly Chen.

Modeling organs

When developing a new drug, researchers identify drug targets based on what they know about the biology of the disease, and then create compounds that affect those targets. Preclinical testing in animals can offer information about a drug's safety and effectiveness before human testing begins, but those tests may not reveal potential side effects, Griffith says. Furthermore, drugs that work in animals often fail in human trials.

"Animals do not represent people in all the facets that you need to develop drugs and understand disease," Griffith says. "That is becoming more and more apparent as we look across all kinds of drugs."

Complications can also arise due to variability among individual patients, including their genetic background, environmental influences, lifestyles, and other drugs they may be taking. "A lot of the time you don't see problems with a drug, particularly something that might be widely prescribed, until it goes on the market," Griffith says.

As part of a project spearheaded by the Defense Advanced Research Projects Agency (DARPA), Griffith and her colleagues decided to pursue a technology that they call a "physiome on a chip," which they believe could offer a way to model potential drug effects more accurately and rapidly. To achieve this, the researchers needed new equipment -- a platform that would allow tissues to grow and interact with each other -- as well as engineered tissue that would accurately mimic the functions of human organs.

Before this project was launched, no one had succeeded in connecting more than a few different tissue types on a platform. Furthermore, most researchers working on this kind of chip were working with closed microfluidic systems, which allow fluid to flow in and out but do not offer an easy way to manipulate what is happening inside the chip. These systems also require external pumps.

The MIT team decided to create an open system, which essentially removes the lid and makes it easier to manipulate the system and remove samples for analysis. Their system, adapted from technology they previously developed and commercialized through U.K.-based CN BioInnovations, also incorporates several on-board pumps that can control the flow of liquid between the "organs," replicating the circulation of blood, immune cells, and proteins through the human body. The pumps also allow larger engineered tissues, for example tumors within an organ, to be evaluated.

Complex interactions

The researchers created several versions of their chip, linking up to 10 organ types: liver, lung, gut, endometrium, brain, heart, pancreas, kidney, skin, and skeletal muscle. Each "organ" consists of clusters of 1 million to 2 million cells. These tissues don't replicate the entire organ, but they do perform many of its important functions. Significantly, most of the tissues come directly from patient samples rather than from cell lines that have been developed for lab use. These so-called "primary cells" are more difficult to work with but offer a more representative model of organ function, Griffith says.

Using this system, the researchers showed that they could deliver a drug to the gastrointestinal tissue, mimicking oral ingestion of a drug, and then observe as the drug was transported to other tissues and metabolized. They could measure where the drugs went, the effects of the drugs on different tissues, and how the drugs were broken down. In a related publication, the researchers modeled how drugs can cause unexpected stress on the liver by making the gastrointestinal tract "leaky," allowing bacteria to enter the bloodstream and produce inflammation in the liver.

Griffith believes that the most immediate applications for this technology involve modeling two to four organs. Her lab is now developing a model system for Parkinson's disease that includes brain, liver, and gastrointestinal tissue, which she plans to use to investigate the hypothesis that bacteria found in the gut can influence the development of Parkinson's disease.

Other applications include modeling tumors that metastasize to other parts of the body, she says.

"An advantage of our platform is that we can scale it up or down and accommodate a lot of different configurations," Griffith says. "I think the field is going to go through a transition where we start to get more information out of a three-organ or four-organ system, and it will start to become cost-competitive because the information you're getting is so much more valuable."

A growing network of lakes on the Greenland ice sheet has been found to drain in a chain reaction that speeds up the flow of the ice sheet, threatening its stability.

Researchers from the UK, Norway, US and Sweden have used a combination of 3D computer modelling and real-world observations to show the previously unknown, yet profound dynamic consequences tied to a growing number of lakes forming on the Greenland ice sheet.

Lakes form on the surface of the Greenland ice sheet each summer as the weather warms. Many exist for weeks or months, but drain in just a few hours through more than a kilometre of ice, transferring huge quantities of water and heat to the base of the ice sheet. The affected areas include sensitive regions of the ice sheet interior where the impact on ice flow is potentially large.

Previously, it had been thought that these 'drainage events' were isolated incidents, but the new research, led by the University of Cambridge, shows that the lakes form a massive network and become increasingly interconnected as the weather warms. When one lake drains, the water quickly spreads under the ice sheet, which responds by flowing faster. The faster flow opens new fractures on the surface and these fractures act as conduits for the drainage of other lakes. This starts a chain reaction that can drain many other lakes, some as far as 80 kilometres away.

These cascading events - including one case where 124 lakes drained in just five days - can temporarily accelerate ice flow by as much as 400%, which makes the ice sheet less stable, and increases the rate of associated sea level rise. The results are reported in the journal Nature Communications.

The study demonstrates how forces within the ice sheet can change abruptly from one day to the next, causing solid ice to fracture suddenly. The model developed by the international team shows that lakes forming in stable areas of the ice sheet drain when fractures open in response to a high tensile shock force acting along drainage paths of water flowing beneath the ice sheet when other lakes drain far away.

"This growing network of melt lakes, which currently extends more than 100 kilometres inland and reaches elevations as high a 2,000 metres above sea level, poses a threat for the long-term stability of the Greenland ice sheet," said lead author Dr Poul Christoffersen, from Cambridge's Scott Polar Research Institute. "This ice sheet, which covers 1.7 million square kilometres, was relatively stable 25 years ago, but now loses one billion tonnes of ice every day. This causes one millimetre of global sea level rise per year, a rate which is much faster than what was predicted only a few years ago."

The study departs from the current consensus that lakes forming at high elevations on the Greenland ice sheet have only a limited potential to influence the flow of ice sheet as climate warms. Whereas the latest report by Intergovernmental Panel on Climate Change concluded that surface meltwater, although abundant, does not impact the flow of the ice sheet, the study suggests that meltwater delivered to the base of the ice sheet through draining lakes in fact drives episodes of sustained acceleration extending much farther onto the interior of the ice sheet than previously thought.

"Transfer of water and heat from surface to the bed can escalate extremely rapidly due to a chain reaction," said Christoffersen. "In one case we found all but one of 59 observed lakes drained in a single cascading event. Most of the melt lakes drain in this dynamic way."

Although the delivery of small amounts of meltwater to the base of the ice sheet only increases the ice sheet's flow locally, the study shows that the response of the ice sheet can intensify through knock-on effects.

When a single lake drains, the ice flow temporarily accelerates along the path taken by water flowing along the bottom of the ice sheet. Lakes situated in stable basins along this path drain when the loss of friction along the bed temporarily transfers forces to the surface of the ice sheet, causing fractures to open up beneath other lakes, which then also drain.

"The transformation of forces within the ice sheet when lakes drain is sudden and dramatic," said co-author Dr Marion Bougamont, also from the Scott Polar Research Institute. "Lakes that drain in one area produce fractures that cause more lakes to drain somewhere elsewhere. It all adds up when you look at the pathways of water underneath the ice."

The study used high-resolution satellite images to confirm that fractures on the surface of the ice sheet open up when cascading lake drainage occurs. "This aspect of our work is quite worrying," said Christoffersen. "We found clear evidence of these crevasses at 1,800 metres above sea level and as far 135 kilometres inland from the ice margin. This is much farther inland than previously considered possible."

While complete loss of all ice in Greenland remains extremely unlikely this century, the highly dynamic manner in which the ice sheet responds to Earth's changing climate clearly underscores the urgent need for a global agreement that will reduce the emission of greenhouse gases.

Morris Animal Foundation-funded researchers uncovered several key factors contributing to a die-off of South American fur seal pups, including mites, pneumonia and sea surface temperature. The findings, published in the Journal of Wildlife Diseases, help scientists better understand the link between environmental factors and health.

"Disease often is the forgotten piece in the conservation puzzle," said Dr. Kelly Diehl, Senior Scientific Programs and Communications Adviser at Morris Animal Foundation. "We hope these findings highlight the urgent need to study the connection between environmental changes and wildlife diseases, studies that will lead to better health and protection of at-risk species. It is an area that Morris Animal Foundation continues to invest in heavily, particularly as we see more species negatively impacted by changes in their habitats."

With support from Morris Animal Foundation, Dr. Mauricio Seguel, a research fellow at the University of Georgia, and his Chilean colleagues studied a mass die-off of South American fur seal pups on Guafo Island in Northern Chilean Patagonia.

"The cause of this increased mortality was a severe lung infection and inflammation leading to bronchopneumonia. It was caused by a combination of parasites (nasal and pulmonary mites) and bacteria. This study shows for first time in this fur seal species that a combination of common parasites and bacteria can have adverse effects in the population," said Dr. Seguel.

Dr. Seguel and his colleagues isolated and identified two types of streptococcus bacteria from bronchopneumonic pups. They believe the mites compromised the pups' breathing and airflow and helped the strep bacteria flourish, leading to severe and fatal disease in the young animals.

Another potential factor in the outbreak was the corresponding and sudden warming of sea surface temperature in the Guafo Island area. Higher sea surface temperatures can lead to changes in the marine food chains that affect multitudes of marine species and can add additional stress to an entire population of animals. Studies in this fur seal population also have shown that the immune system of fur seal pups is sensitive to changes in patterns of maternal care, which vary when environmental conditions in the ocean, such as sea surface temperature, change.

"Today, we worry about how most environments are rapidly changing, and even the most isolated places on earth have felt the effects of human development and impact," said Dr. Seguel. "South American fur seal populations are widespread. For reasons not clearly understood, the remote Chilean populations of this species have had a dramatic decline in the last 30 years. Our team is working to understand the connection between environmental changes and the role of diseases in wildlife systems."

For nearly a decade, researchers have conducted health monitoring studies at Guafo Island. New research by Dr. Seguel and his team is looking at hookworm infections in the South American fur seal pups with up to 100 percent prevalence. These infections cause anemia and retarded growth in a third of the pup population. Like the respiratory mite finding, hookworm prevalence reaches 100 percent in years with higher sea surface temperatures.

""My interest in wildlife diseases started in my childhood, growing up at the Chilean Patagonia. In this place I saw the importance of the environment-wildlife-human linkages and how diseases constantly modified our surroundings. These projects raise concern on the effects of climate change on marine ecosystems. This subject requires further investigation to help improve the health and protection of marine mammals and other animals dependent on these changing habitats," said Dr. Seguel.

Other recent findings by Dr. Seguel's team include a floating debris survey and the role of sea gulls on the health and welfare of South American fur seal pups on Guafo Island that also was funded in part by Morris Animal Foundation.

African Americans with a common genetic variation are at increased risk for developing Alzheimer's disease, while European Americans with the same variation are not, according to a study led by researchers at Rush University Medical Center. They published the study results in the February 22 online issue of the Journal of Clinical Endocrinology and Metabolism.

The genetic variation, known as Thr92AlaD2 polymorphism, affects a gene involved in the activation of thyroid hormone and occurs commonly; almost half the population are carriers of this polymorphism. The study found that African Americans with this polymorphism are 30 percent more likely to develop Alzheimer's disease dementia than the African American without the genetic polymorphism. Whereas in European Americans, this gene wasn't associated with increased risk of Alzheimer's. This is a remarkable juxtaposition.

"This correlation only shows up in African-Americans. We have some ideas but aren't sure why," said Elizabeth McAninch MD, study author and assistant professor of the Division of Endocrinology and Metabolism at Rush.

Discovery is twist in research that began with thyroid gland

The discovery was the latest twist in an investigation that began years ago in Rush's endocrinology division under the leadership of Dr. Antonio Bianco, a thyroid expert and the director of the present studies. Endocrinologists provide care for hormone imbalances that cause health problems.

The Thr92AlaD2 polymorphism affects an enzyme that activates thyroid hormones. The enzyme is most important when considering patients with a condition known as hypothyroidism, which occurs when there is insufficient thyroid hormone being produced by the thyroid gland. In most cases, this condition can be controlled with the standard treatment for hypothyroidism, a drug called levothyroxine. However, about 15 percent of patients treated with levothyroxine consistently say it doesn't help them feel better.

Wondering what was behind those reports, McAninch and colleagues at Rush previously obtained and analyzed brain tissue from the University of Miami Brain Bank from deceased Caucasian male organ donors who at their time of death were young and healthy, without known thyroid problems, to see if they could find any clues. To their surprise, the brains of the healthy donors who had the polymorphism displayed biomarkers that are known to play a role in neurodegenerative brain disease.

"This was a shock to us and deserved more investigation," McAninch recalled.

Researchers then drew on data from long-term studies of Alzheimer's

The endocrinologists then enlisted the help of Rush researchers who specialize in the issues of the aging brain, and the expanded team set to work with data from three long-term group studies done at Rush from 1993 to 2012 -- the Chicago Health and Aging Project (CHAP), the Religious Orders Study (ROS), and the Rush Memory and Aging Project (MAP).

The CHAP cohort includes 3656 participants, 2321 of whom are African American, who received cognitive testing in three-year cycles for more than 18 years. In ROS and MAP, 1,707 European American participants without known dementia were enrolled and had annual evaluations.

Again, McAninch and colleagues also continued to collaborate with the University of Miami Brain Bank to obtain and study brain tissue from young, healthy African American brain donors.

Through utilizing the CHAP data, which has both African American and European American participants, this unique racially-stratified outcome revealed itself. "That's when we saw this huge discrepancy in risk for Alzheimer's disease dementia," McAninch said.

Questions remain to be answered in future studies

Minorities tend to be understudied in medical research in general, and specifically there needs to be more, larger studies of African Americans to evaluate the risk of Alzheimer's, McAninch observed. "A strength of this study is credited to the amazing resource we have in these three cohort studies here at Rush, where we were able to look at the differences between African-Americans and European-Americans," she says.

The Rush-led team is already planning the next inquiry, McAninch says, "to try to understand why African-Americans have this risk, while the European-Americans do not."

The work of faculty and students from The University of Texas at El Paso (UTEP) has yielded the first evidence of how waterborne microinvertebrates move across vast expanses of arid desert.

An article published March 13, 2018 in Limnology and Oceanography Letters, a publication of the Association for the Sciences of Limnology and Oceanography, details for the first time how high desert winds disperse small invertebrates and how they colonize hydrologically disconnected basins throughout the region.

"These novel findings might have large implications for freshwater systems," said Elizabeth J. Walsh, Ph.D., professor in UTEP's Department of Biological Sciences and director of the doctoral program in Ecology and Evolutionary Biology. "As climate changes and water patterns shift, our work might help others understand the intricacies of the wind-aided dispersal of freshwater organisms. It's important because these organisms are the base of the food web. How they move will affect the movement of the biological communities that are built up around them."

Walsh added that the impetus for the research grew out of a previous five-year study of Chihuahuan Desert aquatic environments funded by the National Science Foundation. Part of that project involved characterizing the biodiversity of microinvertebrates at 300 sites. Researchers wanted to better understand how organisms were colonizing these bodies of water that were separated by vast distances of desert and not tied together by hydrological links such as drainage routes.

"If they weren't being moved by water, and they weren't being moved by other animals, then the next thing we thought is, 'It has to be the wind,'" Walsh said.

Enter Thomas E. Gill, Ph.D., UTEP professor in the Department of Geological Sciences and Environmental Science and Engineering Program, who while conducting concurrent studies on Chihuahuan Desert wind storms, pondered, "What kinds of living things are being carried along with the dust?"

What followed was a multi-year interdisciplinary research effort that collected dust samples; confirming those samples contained microinvertebrates in dormant, developmental stages; rehydrating them in laboratory settings; and utilizing next-generation sequencing to determine which organisms were present in the dust.

The last step involved moving the dust through a simulated storm to determine if the organisms could survive being blasted through the air across lengthy distances. Doctoral student Jose A. Rivas Jr. and Gill worked with Scott Van Pelt, Ph.D., a soil science researcher with the U.S. Department of Agriculture, to conduct such a test at the USDA Agricultural Research Service's wind tunnel facility in Big Spring, Texas.

"We basically simulated a wind storm," Gill said. "We took the clean desert soil, in which we mixed microinvertebrates, and blew it into the air. After this energetic, turbulent journey through the wind tunnel, our team showed that those organisms, which are about the size of grains of sand in their dormant stage in their development, survived getting sandblasted into the air. They can fly through the atmosphere, maybe hundreds of miles in viable conditions, and still wake up."

Gill said the group's findings will help inspire further research on the movement of organisms. He added that the effort that took place at UTEP was a successful collaboration because of support from the UTEP Interdisciplinary Research (IDR) program, the National Institutes of Health, the National Science Foundation and the National Oceanic and Atmospheric Administration Center for Atmospheric Sciences (NCAS). He also said the work conducted by doctoral students Rivas and Jon Mohl - who served as the study's lead and second authors - was vital to the effort.

"It's a very exciting and unique project," said Rivas, who was the study's lead author. "Dust storms are a huge part of the Southwest. We interact with them every spring. What's interesting is not only learning about dust storms but finding out what exactly is being transported, what's in the dust? This is especially important in understanding the diversity of our Chihuahuan Desert ecosystem. Learning how small, aquatic animals are transported and colonize new areas will lead to insights into how communities in tem

Up to half of plant and animal species in the world's most naturally rich areas, such as the Amazon and the Galapagos, could face local extinction by the turn of the century due to climate change if carbon emissions continue to rise unchecked.

Even if the Paris Climate Agreement 2°C target is met, these places could lose 25% of their species according to a landmark new study by the University of East Anglia (UK), the James Cook University (Australia), and WWF.

Published today in the journal Climatic Change and just ahead of Earth Hour, the world's largest environmental event, researchers examined the impact of climate change on nearly 80,000 plant and animal species in 35 of the world's most diverse and naturally wildlife-rich areas.

It explores a number of different climate change futures - from a no-emissions-cuts case in which global mean temperatures rise by 4.5°C , to a 2°C rise, the upper limit for temperature in the Paris Agreement . Each area was chosen for its uniqueness and the variety of plants and animals found there.

The report finds that the Miombo Woodlands, home to African wild dogs, south-west Australia and the Amazon-Guianas are projected to be some the most affected areas. If there was a 4.5°C global mean temperature rise, the climates in these areas are projected to become unsuitable for many the plants and animals that currently live there meaning:

Up to 90% of amphibians, 86% of birds and 80% of mammals could potentially become locally extinct in the Miombo Woodlands, Southern Africa

The Amazon could lose 69% of its plant species

In south-west Australia 89% of amphibians could become locally extinct

60% of all species are at risk of localised extinction in Madagascar

The Fynbos in the Western Cape Region of South Africa, which is experiencing a drought that has led to water shortages in Cape Town, could face localised extinctions of a third of its species, many of which are unique to that region.

As well as this, increased average temperatures and more erratic rainfall could become be the "new normal" according to the report - with significantly less rainfall in the Mediterranean, Madagascar and the Cerrado-Pantanal in Argentina. Potential effects include;

Pressure on the water supplies of African elephants - who need to drink 150-300 litres of water a day

96% of the breeding grounds of Sundarbans tigers could become submerged by sea-level rise

Comparatively fewer male marine turtles due to temperature-induced sex assignment of eggs.

If species can move freely to new locations then the risk of local extinction decreases from around 25% to 20% with a 2°C global mean temperature rise. If species cannot they may not be able to survive. Most plants, amphibians and reptiles, such as orchids, frogs and lizards cannot move quickly enough keep up with these climatic changes.

Lead researcher Prof Rachel Warren from the Tyndall Centre for Climate Change Research at UEA said: "Our research quantifies the benefits of limiting global warming to 2°C for species in 35 of the world's most wildlife-rich areas. We studied 80,000 species of plants, mammals, birds, reptiles and amphibians and found that 50% of species could be lost from these areas without climate policy. However, if global warming is limited to 2°C above pre-industrial levels, this could be reduced to 25%. Limiting warming to within 1.5°C was not explored, but would be expected to protect even more wildlife."

Overall the research shows that the best way to protect against species loss is to keep global temperature rise as low as possible.

The Paris Agreement pledges to reduce the expected level of global warming from 4.5°C to around 3°C, which reduces the impacts, but we see even greater improvements at 2°C; and it is likely that limiting temperature rise to 1.5°C would protect more wildlife.

This is why on 24 March millions of people across the world will come together for Earth Hour, to show their commitment to reducing global emissions and protecting people and wildlife from the impacts of climate change. The event also sends a clear message to business and government that there is a global will to change this trajectory.

Tanya Steele, CEO of WWF commented: "Within our children's lifetime, places like the Amazon and Galapagos Islands could become unrecognisable, with half the species that live there wiped out by human-caused climate change. Around the world, beautiful iconic animals like Amur tigers or Javan rhinos are at risk of disappearing, as well as tens of thousands plants and smaller creatures that are the foundation of all life on earth. That is why this Earth Hour we are asking everyone to make a promise for the planet and make the everyday changes to protect our planet."

The models used in this research come from the Wallace Initiative, a near decade long partnership between the Tyndall Centre at UEA, eResearch at James Cook University, the Global Biodiversity Information Facility and WWF.

Dr Jeff Price, coordinator of the Wallace Initiative and also from UEA, said: "This research provides a view on the differing spatial impacts of climate change on biodiversity. It shows the benefits of combining citizen science with the research and resources of highly-ranked universities to assist an NGO with their conservation activities."

'The implications of the United Nations Paris Agreement on climate change for globally significant biodiversity areas' is published in the journal Climatic Change on March 14, 2018.

TAMPA, Fla. - Drug therapies that target a specific molecule have changed the way patients are treated for cancer and greatly improved survival rates. However, some patients do not respond to these therapies because the drug is not reaching the tumor cells effectively. In a new study published in Scientific Reports, Moffitt Cancer Center researchers combined single-cell imaging of cancer cells in mice with mathematical modeling to determine which drug characteristics are the most important for efficient drug uptake.

One of the inherent problems with targeted therapies is that tumors and their surrounding environment are complex and heterogeneous. Not all cells in a given tumor are alike. They can differ from one another in the expression of the targeted membrane receptors which may result in inadequate uptake and non-uniform response to the targeting drug. Additionally, the surrounding tumor environment is composed of different cell types with different properties and densities that can impact the ability of a drug to be effective.

These variations make it difficult to develop drugs that can effectively target all of the cells in a tumor. Furthermore, these cellular and genetic differences may cause a patient to be unresponsive to a cancer-targeted drug because some tumor cells may not be fully exposed to the drug and this incomplete exposure may enable these cells to develop drug resistance.

"Clinical success or failure of targeted therapy depends heavily on whether the drug molecules are able to reach all tumor cells and engage with their molecular targets to invoke the desired therapeutic effect," said Kasia A. Rejniak, Ph.D., associate member of the Department of Integrated Mathematical Oncology at Moffitt. This work was accomplished through collaboration between Rejniak computational group and the laboratory group of Dave L. Morse, Ph.D., associate member of the Department of Cancer Physiology.

The standard methods that scientists use to study drug uptake are based on the idea that a tumor and its surroundings have uniform characteristics. However, this assumption is inaccurate and may lead to a one-size-fits-all approach to treatment. The Moffitt research team wanted to take a different approach to study drug uptake. They used mathematical modeling and imaging techniques that allowed them to track and predict the ability of a single cell to take up a drug. Within their model, they compared different drug characteristics and tumor properties to determine which conditions lead to more effective drug uptake by a cell.

They discovered that the amount of drug that binds to a cell is dependent on how quickly a drug diffused through the tissue rather than on the concentration of drug that enters the tissue. Drugs that diffused quickly tended to bind more effectively to cells that were further away from blood vessels. Alternatively, drugs that diffused slowly tended to bind to cells that were closer to blood vessels and were more effective when the cells were tightly packed. The researchers also showed that drugs that are released quickly are able to bind more effectively to cells with different levels of drug receptors.

These discoveries suggest that changing different properties of a drug or the way a drug is administered may lead to increased delivery to tumor cells. "For example, to treat the fast-growing cells located near the vasculature, slowly diffusing agents may be beneficial. In contrast, for the dormant cells in poorly vascularized regions, the highly mobile agents may be preferential, or in some cancers, local injection directly to the tumor site may be beneficial," explained Rejniak. Ultimately, the researchers hope that their approach could eventually be used to design more personalized treatment options for cancer patients.

WEST LAFAYETTE, Ind. -- Researchers may be able to stop the replication of Ebola virus by mutating its most important protein, according to a paper published in the Journal of Biological Chemistry.

Researchers were able to mutate Viral Protein 40 (VP40) in a way that changed the residues of the protein, blocking the budding and replication of Ebola virus in a model system.

VP40 is a peripheral membrane protein that regulates viral budding from the plasma membrane. It interacts with a human plasma-membrane lipid, phosphatidylserine, to facilitate replication of the virus. All animal viruses have to cross membranes for cell entry and exit.

The research team, led by Robert Stahelin of Purdue University, found the specific parts of VP40 that bind with the lipid: a cationic patch on the end of an amino acid chain. This site controls the ability of the protein to form a lipid envelope, the layer that protects the virus from the outside environment.

Water-attracting residues at this site are critical for membrane penetration and budding. Substituting those residues with alanine, which is hydrophobic, reduced lipid binding by 40-fold and stopped localization to the plasma membrane.

VP40 is a transformer protein, capable of rearranging itself into different structures: monomer, dimer and octamer. These various structures interact with the lipid differently, according to the paper. The dimer is best equipped to facilitate replication, performing twice as well as the monomer, and nearly 10 times better than the octamer.

"It's exciting to learn that these different oligomeric structures bind differently with the human lipid cells," Stahelin said. "That might explain why there are different roles for this protein in the viral replication cycle."

There are currently no FDA-approved vaccines or therapeutics available for Ebola virus. Outbreaks are rare but deadly, with fatality rates as high as 90 percent. Knowing how and where the protein interacts with the lipid could allow researchers to better target it with therapeutics.

"This helps us understand how the virus uses human cell membranes to replicate and form new virus particles. The virus needs this one lipid to form the new particle and infect other cells," Stahelin said. "We've been targeting human cells with therapeutics that modulate the way the cell makes lipids, and we like to target the human cell because it isn't likely to mutate and become resistant to the drug.

Cellular and in vitro models were used in this study. In vitro models were used to quantify how well VP40 binds to synthetic membranes. The researchers mutated the DNA code to change the amino acid sequence of VP40, purified those proteins to homogeneity and compared their bindings to that of the original VP40.

In cellular experiments, live cell imaging was used to monitor VP40 localization in human cells. The movement of the mutant VP40 and the original VP40 were compared to see how they bind to the human cell plasma membrane, the site of viral replication.

LA JOLLA, CA - March 12, 2018 - Researchers at The Scripps Research Institute (TSRI) have designed a new molecule-building method that uses sulfones as partners for cross-coupling reactions, or the joining of two distinct chemical entities in a programmed fashion aided by a catalyst. The technique, described recently in the journal Science, paves the way toward other new chemical reactions and facilitates the synthesis of pharmaceutically-relevant molecules.

"It's already clear that this method opens the door to creating new types of compounds and new types of bonds," says Phil S. Baran, PhD, senior author of the study and Darlene Shiley Professor of Chemistry at TSRI.

This work was inspired by previous cross-coupling chemistry developed in the Baran lab, and catalyzed by discussions with pharmaceutical industry partners who view this as an area of major unmet need. Baran and his colleagues have previously studied decarboxylative cross-coupling reactions, where commonly-found carboxylic acids are transformed into many different molecules using inexpensive metal catalysts and techniques commonly used for amide-bond synthesis. Throughout these studies, Baran and coworkers showed that decarboxylative cross-coupling can have broad applicability and facilitate the synthesis of pharmaceuticals and natural products. These reactions hinge on the transfer of one electron from the metal catalyst to an activated carboxylic acid, which allows for the cross-coupling to occur.

In this work, the authors demonstrate the new desulfonylative cross-coupling reaction by synthesizing over 60 representative molecules, including alkyl-fluorinated compounds inaccessible with earlier generation methodologies developed in the Baran group. Access to such compounds are critical for drug discovery campaigns, since fluorine atoms enhance drug-like molecular properties. Representative molecules described in the Science paper include some reported by Merck and Novartis in published patents.

Baran's group has already made their sulfone reagents and methods used in this study available to other chemists via Twitter who would like to use the technique. The new method is already having an impact on drug discovery programs at pharmaceutical companies with whom TSRI collaborates.

"I think the job of chemists in academia is to make things simpler. If we can have a small positive influence in making medicinal chemists lives easier, that will be a success for us," says Baran. "This chemistry is another step in that direction."