Tech

A team of researchers at the University of Minnesota have, for the first time, fully 3D printed an array of light receptors on a hemispherical surface. This discovery marks a significant step toward creating a "bionic eye" that could someday help blind people see or sighted people see better.

The research is published today in Advanced Materials, a peer-reviewed scientific journal covering materials science. The author also holds the patent for 3D-printed semiconducting devices.

"Bionic eyes are usually thought of as science fiction, but now we are closer than ever using a multimaterial 3D printer," said Michael McAlpine, a co-author of the study and University of Minnesota Benjamin Mayhugh Associate Professor of Mechanical Engineering.

Researchers started with a hemispherical glass dome to show how they could overcome the challenge of printing electronics on a curved surface. Using their custom-built 3D printer, they started with a base ink of silver particles. The dispensed ink stayed in place and dried uniformly instead of running down the curved surface. The researchers then used semiconducting polymer materials to print photodiodes, which convert light into electricity. The entire process takes about an hour.

McAlpine said the most surprising part of the process was the 25 percent efficiency in converting the light into electricity they achieved with the fully 3D-printed semiconductors.

"We have a long way to go to routinely print active electronics reliably, but our 3D-printed semiconductors are now starting to show that they could potentially rival the efficiency of semiconducting devices fabricated in microfabrication facilities," McAlpine said. "Plus, we can easily print a semiconducting device on a curved surface, and they can't."

McAlpine and his team are known for integrating 3D printing, electronics, and biology on a single platform. They received international attention a few years ago for printing a "bionic ear." Since then, they have 3D printed life-like artificial organs for surgical practice, electronic fabric that could serve as "bionic skin," electronics directly on a moving hand, and cells and scaffolds that could help people living with spinal cord injuries regain some function.

McAlpine's drive to create a bionic eye is a little more personal.

"My mother is blind in one eye, and whenever I talk about my work, she says, 'When are you going to print me a bionic eye?'" McAlpine said.

McAlpine says the next steps are to create a prototype with more light receptors that are even more efficient. They'd also like to find a way to print on a soft hemispherical material that can be implanted into a real eye.

McAlpine's research team includes University of Minnesota mechanical engineering graduate student Ruitao Su, postdoctoral researchers Sung Hyun Park, Shuang-Zhuang Guo, Kaiyan Qiu, Daeha Joung, Fanben Meng, and undergraduate student Jaewoo Jeong.

The research was funded by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (Award No. 1DP2EB020537), The Boeing Company, and the Minnesota Discovery, Research, and InnoVation Economy (MnDRIVE) Initiative through the State of Minnesota.

To read the full research paper entitled "3D Printed Polymer Photodetectors," visit the Advanced Materials website.

DURHAM, N.C. - Over the long-run, the race will indeed go to the slower, steadier animal.

"The fable of 'The Tortoise and the Hare' is a metaphor about life, not a story about a race," said Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke University. "We see in animal life two starkly different lifestyles -- one with nearly steady feeding and daily sleep and another with short bursts of intermittent feeding interspersed with day-long siestas. Both of these patterns are the rhythms of living that Aesop taught."

In the iconic parable, Aesop tells of a race between a fast but often-distracted hare and a slow but relentless tortoise. Readers are supposed to be surprised when the tortoise manages to defeat the hare, coining the phrase "slow and steady wins the race." But according to Bejan's new analysis, they shouldn't be.

Published on August 27 in the journal Scientific Reports, Bejan analyzes the reported speeds of animals based on land, air and water. The results show that some of the world's fastest animals are actually some of the slowest when their movements are averaged throughout their lifetimes.

Bejan then goes on to demonstrate that this counterintuitive result is also true of the modern aviation industry. With data from hundreds of historical airplane models in hand, Bejan shows that the general trend in their design is for size and speed to increase hand-in-hand.

Except, that is, for the modern jet fighter.

Just like in the animal world, the jet fighter may be faster than other airplanes in short bursts, but it spends much of its time grounded. When averaged over its service lifetime, jet fighters are surprisingly slow when compared to models designed for transport or reconnaissance.

The study emerged as a consequence of a previous paper that used Bejan's constructal theory to show that all animals' speeds tend to rise along with their body mass and adhere to a similar ratio. For example, the stride frequency of running vertebrates bears the same relationship to the animals' mass as does the rate at which fish swim. Similarly, the velocity of runners conforms to the same principles as the speed of birds in flight. These models can be used to predict future evolutionary trends and design directions for aircraft and other vehicles.

"When I would give speeches on this topic, somebody would always bring up outliers to this principle such as the cheetah as counterexamples," said Bejan. "But this study shows that these 'outliers' are to be expected and, when looked at over their lifetimes, are not so different from their lumbering cousins after all."

Munich, Germany - 27 Aug 2018: Tafamidis is the first treatment to improve survival and reduce hospitalisations in a rare heart condition called transthyretin amyloid cardiomyopathy, according to late breaking research presented today in a Hot Line Session at ESC Congress 20181 and published in the New England Journal of Medicine.

Professor Claudio Rapezzi, principal investigator, University of Bologna, Italy, said: "There are no medications specifically approved for the treatment of transthyretin amyloid cardiomyopathy. Tafamidis improved survival and quality of life, and reduced hospitalisations, indicating that it could be an effective therapy for these patients. A submission to the regulatory authorities for marketing approval is in process as a consequence of this study."

Transthyretin amyloid cardiomyopathy is a rare, progressive, fatal disease. The hereditary form is caused by mutations in the TTR gene and typically presents in 50-70 year-olds, while the acquired (wild-type) form presents in 60-80 year-olds. The disease is caused when the transport protein, transthyretin, becomes unstable and misfolds, leading to the formation of amyloid, which is deposited in the heart. This causes the heart muscle to become stiff and results in heart failure.

Patients have debilitating symptoms common to heart failure, such as shortness of breath, fatigue, orthostatic hypotension, and syncope, leading to frailty and poorer quality of life. Patients survive an average of three to five years after diagnosis. There are no approved drugs to improve survival, and therapy is limited to managing symptoms.

Tafamidis stabilises transthyretin, preventing misfolding and the formation of amyloid. Treatment with this therapy delays neurologic progression in transthyretin familial amyloid polyneuropathy, a similar condition in which amyloid is deposited in the nerves after transthyretin misfolding. The drug is approved for this condition in the EU.

The medicine has not been approved for the treatment of transthyretin amyloid cardiomyopathy, but has orphan drug designation from the European Medicines Agency (EMA) and Fast Track designation from the US Food and Drug Administration (FDA).

The ATTR-ACT trial2 assessed the efficacy and safety of tafamidis in patients with hereditary and acquired transthyretin amyloid cardiomyopathy. The trial enrolled 441 patients aged 18-90 years from 48 centres in 13 countries. Patients were randomised in a 2:1:2 ratio to tafamidis 80 mg, tafamidis 20 mg, or placebo - all taken orally, once a day, for 30 months.

The primary endpoint was the hierarchical combination of all-cause death and cardiovascular-related hospitalisations from baseline to 30 months. The two tafamidis groups were combined and compared with the placebo group. Secondary outcomes included the change from baseline to 30 months in exercise capacity (assessed with the six-minute walk test) and in health-related quality of life (assessed using the Kansas City Cardiomyopathy Questionnaire).

A total of 264 patients received the drug and 177 received placebo. Tafamidis significantly reduced death and cardiovascular-related hospitalisation compared to placebo (p=0.0006). During the 30-month follow-up, 78 (29.5%) patients receiving the medicine died compared to 76 (42.9%) receiving placebo - this included patients who underwent heart transplant or received a cardiac mechanical assist device as these were classified as death in the analysis.3 Rates of cardiovascular-related hospitalisations were 52.3% and 60.5% in the tafamidis and placebo groups, respectively.

The therapy also reduced the decline in six-minute walk distance and quality of life compared with placebo. The incidence of individual adverse events were similar or fewer with drug treatment. Discontinuations of study drug due to treatment-related adverse events were less common with tafamidis than placebo.

Professor Rapezzi said: "ATTR-ACT is the largest randomised clinical trial in patients with transthyretin amyloid cardiomyopathy to date. The trial showed that tafamidis is superior to placebo in reducing the risk of death and cardiovascular-related hospitalisations. Tafamidis also reduced the decline in functional capacity and quality of life and had a favourable safety profile in these patients."

He concluded: "These findings provide strong evidence that tafamidis is an effective therapy for patients with transthyretin amyloid cardiomyopathy and can modify the natural history of this disease."

Ants and humans live in large societies that allow for elaborate structures -- nests, cities -- filled with resources. Sometime in the distant past, individuals must have organized themselves into the first simple groups, precursors of these complex societies. But how?

A team of researchers from Princeton University and Rockefeller University tackled this question by combining sophisticated mathematical models with detailed empirical observations of the clonal raider ant (Ooceraea biroi).

"Our findings show that there are some very significant and unexpected benefits that emerge even in very small groups, which could provide the critical steppingstone to allow for larger, more complex societies," said Christopher Tokita, a graduate student in Corina Tarnita's lab in ecology and evolutionary biology (EEB).

The scientists found that ant groups with as few as six individuals experienced significant benefits from group living, as measured by better-surviving and faster-growing babies. Their results appear in the journal Nature.

"It's easy to see how individuals work together in more complex societies, such as those with queens and workers, because they have distinct roles," said Rockefeller's Daniel Kronauer. "But that's not how insect societies started out."

In fact, this is a general conundrum across biological systems, added Tarnita. "From multicellular organisms to insect groups to human societies, nature has a remarkable ability to construct complex groupings, but we have yet to fully understand what happened at the beginning to facilitate their emergence."

Moreover, she said, "we are used to thinking of certain features, such as division of labor or cellular differentiation, as characteristic of large, complex groups, but are we right to think that way?"

The scientists used ants to try to understand what the earliest precursors of these complex groups might look like. Small insect groups are more successful than solitary individuals for two main reasons, said Tokita, a co-author on the Nature paper. "First, there are 'more hands to do work,' so to speak," he said. "Important tasks don't slip through the cracks, because chances are there's always an individual to do the task."

Second, and unexpectedly, "incipient division of labor emerges already in these tiny groups of nearly identical individuals," added Tarnita.

The researchers studied ant groups ranging in size from one to 16 individuals. They chose this species because of its unusually simple social organization: colonies have no queens, just genetically identical workers that reproduce simultaneously.

"It was an ideal pairing of experiments and theory," said Tokita. Researchers in Kronauer's lab at Rockefeller observed ants in long-running experiments that informed and guided the mathematical models created by the Princeton team.

"With the model, we were able to ask questions that might not be possible to ask otherwise," said Tokita. "For example, our model predicted that group needs, like hunger, were becoming more stable as groups got larger and division of labor emerged. This was the result of tasks, like foraging and nursing, being more consistently performed and less neglected. While the Kronauer Lab couldn't measure hunger levels in their colonies, they were able to go back to their camera-tracking data and confirm that, as colonies grew larger, those tasks were indeed being more consistently performed. It was amazing! We had a prediction from our model that, when tested against the empirical data, actually held up really well."

At the outset, the researchers had assumed that the incipient division of labor was the key to success in their larger groups, a common assumption among modern economists as well. They were surprised to find that this was not completely true. Division of labor contributed to but was not necessary to produce the observed increase in fitness with group size, said Tokita. "Instead, we showed theoretically that increases in group size alone, even in the absence of division of labor, could create benefits for these small colonies."

In addition, their findings challenge a popular belief about group dynamics, that strong groups require strong leaders. "Complicated behaviors, like the division of labor, can self-organize," Tokita said. "The ant species we used does not have a leader at all. Instead, all group members are workers and they each lay their own eggs."

This "impressive collaboration between empirical and theoretical research" confirms predictions Tarnita made in 2010 with co-authors Martin Nowak and Edward Wilson, said Nowak, who was not involved in the current research. The earlier paper, also in Nature, argued that complex societies such as those of ants or bees could evolve only "if the benefits of staying together arise already for small group size," which is exactly what this new collaboration determined, Nowak said.

"Experimentally confirming that ants satisfy this very strong requirement was impossible in 2010," said Tarnita. It was only what Tarnita described as "a huge effort by the Kronauer Lab to turn ants into a lab model organism" that made this recently possible. "It's been very exciting to empirically revisit these ideas and, not only find support, but also reveal such unexpectedly rich behavior in such small groups," she said.

These findings have significant implications for understanding the evolution of social behavior. They show that "a lot can happen very early on and that what we think are hallmarks of complex societies could actually have originated in the simplest groups," Tarnita said.

If you've ever experienced jet lag, you are familiar with your circadian rhythm, which manages nearly all aspects of metabolism, from sleep-wake cycles to body temperature to digestion. Every cell in the body has a circadian clock, but researchers were unclear about how networks of cells connect with each other over time and how those time-varying connections impact network functions.

In research published Aug. 27 in PNAS, researchers at Washington University in St. Louis and collaborating institutions developed a unified, data-driven computational approach to infer and reveal these connections in biological and chemical oscillatory networks, known as the topology of these complex networks, based on their time-series data. Once they establish the topology, they can infer how the agents, or cells, in the network work together in synchrony, an important state for the brain. Abnormal synchrony has been linked to a variety of brain disorders, such as epilepsy, Alzheimer's disease and Parkinson's disease.

Jr-Shin Li, professor of systems science & mathematics and an applied mathematician in the School of Engineering & Applied Science, developed an algorithm, called the ICON (infer connections of networks) method, that shows for the first time the strength of these connections over time. Previously, researchers could only determine whether a connection existed between networks.

Li and collaborators first tested their method on simulated network of different sizes they created. Next, they tested the method on a network of oscillators -- populations of dynamic units that repeatedly fire together, go silent, then fire together again -- created in the lab by Istvan Kiss, professor of chemistry at Saint Louis University. When they applied Li's algorithm to the network of interactions among the synthetic oscillators, the results matched what Kiss had determined through his experiments, finding the same connections in a network of 15 chemical oscillators. Such prediction of this dynamic topology was not previously possible, the researchers said.

Li said this method has a variety of applications beyond cell networks.

"This lays the foundation to analyze real-world complex networks of tremendous size, such as transportation, internet, power grids, and social networks," he said.

Li also collaborated with Erik Herzog, professor of biology in Arts & Sciences at Washington University who studies the cellular and molecular basis of circadian rhythms in mammals, to determine the connections between cells in a mouse brain. Herzog measured the circadian rhythm from 541 cells from the right and left sides of the mouse brain, then asked Li to estimate how these connections changed over time -- something that hadn't been done in the biology field.

"The connection at one time may be strong, but at another time it may be stronger or weaker, so we can use this data to recover the functional connectivity," Li said. "If we know this, then we know the network, then we can do more study and investigate over time whether this network will be synchronized or whether specific dynamic patterns will emerge."

Herzog said ICON would help him and other scientists to understand principles that allow systems to efficiently synchronize.

"For example, we want to define the essential features of networks of cells that keep daily time under different conditions," Herzog said. "We hope that ICON can map out connections and describe the interactions, such as attraction versus repulsion, of cells at different developmental stages so we can understand more about how circadian systems assemble after birth, adapt to challenges such as winter or summer, and fail to coordinate during stressors such as shift work or flying across multiple time zones."

In another experiment, collaborator William Schwartz, a former visiting professor of biology at Washington University now at the University of Texas at Austin, tested the method on seven groups of five mice who were housed together for a period of time as social networks. Schwartz measured the oscillations of the mice at the end of the experiment and provided the data to Li, who applied his algorithm to infer results from the data. In the end, both Schwartz and Li found that four of the groups of mice had social synchronization because they had the same body temperatures at the end of their time together. Three groups did not have the same body temperatures and were not socially synchronized.

As ocean conservation efforts kick into high gear amid concerns over climate change, food insecurity and habitat degradation, a disturbing phenomenon may also be on the rise: preemptive overfishing in a given area in anticipation of impending conservation policies.

"We show that efforts to close off fishing in a major part of the world's ocean paradoxically led to more fishing, thus undermining the very conservation goal that was being sought," Kyle Meng, a professor at the UC Santa Barbara Bren School of Environmental Science & Management, said of his new research. Meng is a co-author of "The blue paradox: Preemptive overfishing in marine reserves," now published in the Proceedings of the National Academy of Sciences. The findings have implications for general conservation efforts, as well as methods that scientists use to monitor and evaluate policy efficacy.

According to the researchers, while efforts to curtail overfishing and promote ocean biodiversity through the establishment of marine reserves have generally had positive results, the period leading up to implementation of policy can be a particularly vulnerable one. Fishermen, perhaps fearing the decline of their livelihood, recreation or general entitlement to their activity, tend to over-extract resources immediately before the protections become official.

"A simple way to think about it is that fishers face a 'use it or lose it' dilemma," said Grant McDermott, a professor at the University of Oregon and fellow co-author of the study. "And, like I presume many of us would in their situation, they invariably choose to fish as much as possible while they still can."

Such behavior was noted in the team's recent observation of the Phoenix Islands Protected Area (PIPA), a swath of central Pacific Ocean roughly the size of California, known for its remarkably diverse marine ecosystem. Using datasets and continuous satellite monitoring provided by Global Fishing Watch, the researchers found that in the period leading up to the ban on fishing in PIPA that was enacted on January 1, 2015 -- a successful ban celebrated by conservationists and scientists alike -- preemptive fishing placed PIPA in a more impoverished state by the time the policy was enforced. In fact, this extra preemptive fishing was equivalent to 1.5 years of avoided fishing following the ban.

Such events are not new, according to the study. In other environmental domains, similar policies affecting endangered species, water and land resources, and climate change policy, have seen similar anticipatory behaviors. For example, in advance of the 1973 Endangered Species Act (ESA), private landowners in North Carolina and elsewhere deforested their properties to minimize land-use restrictions that would go into play upon settlement by woodpecker colonies. As a result, red-cockaded woodpecker habitats declined after the bird gained protected status via ESA. This phenomenon also was evident in non-environmental circles, such as after the 2012 Sandy Hook massacre, when calls for tougher legislation led to a surge in firearm sales.

However, these previous examples are all land-based and involve clearly demarcated property rights, according to the authors. The striking thing about this latest study, they said, is that it demonstrates preemptive resource extraction can occur even in a marine setting, where property rights are usually far from secure. The precise conditions that would allow for this to occur in such a "commons" remains a topic for future research, however.

"While we do not know exactly why this behavior is occurring just yet," said Meng, "it is not hard to imagine that a fisher who has expertise in a particular fishing region may want to take advantage of that experience before a ban is implemented. After the ban, that know-how no longer has any value."

"Our goal in this study was to find out whether preemptive extraction is actually occurring in a marine setting and to quantify the effects," added McDermott. "Now that we've established those facts, we hope to uncover the underlying mechanisms more precisely in subsequent research."

In terms of marine overfishing, the researchers extrapolate that if other marine reserve announcements were to trigger similar preemptive fishing behavior, it could temporarily increase the share of global over-extracted fisheries from 65 percent to 72 percent. This increase, they say, undermines the very objective of the marine reserve and can push fisheries and fish populations in an already precarious state to a point of no return even before a ban is enacted. In addition, they said, a further depleted fish population means less income for fishers and the communities they live in.

"While a certain amount of preparatory time is needed for any future policy, we do urge future marine reserves to be implemented in a quicker manner," said co-author Christopher Costello, who is a professor at the Bren School. "Additionally, the ability to continuously monitor fishing activity around the world using data from Global Fishing Watch also suggests that such preemptive action can be detected and discouraged from happening even before the fishing ban takes place."

The group is currently investigating those possible remedies and exploring why fishers are engaging in this preemptive fishing behavior.

"Undercovering the exact motives behind this phenomenon will help us go a long way toward ultimately preventing it from happening," Meng said.

Munich, Germany - 27 Aug 2018: The antithrombin drug rivaroxaban does not reduce the risk of a composite endpoint of survival, myocardial infarction and stroke after an episode of worsening heart failure in patients with heart failure, sinus rhythm, and coronary artery disease, according to late breaking results from the COMMANDER HF trial presented today in a Hot Line Session at ESC Congress 20181 and with simultaneous publication in NEJM.

After an episode of worsening heart failure, patients experience high rates of hospital readmission and death, particularly in the first few months. Previous studies have suggested that the enzyme thrombin may contribute to these poor outcomes by inducing inflammation, endothelial dysfunction, and clot formation (thrombosis) in blood vessels.2

Rivaroxaban is an oral, direct factor Xa inhibitor that reduces thrombin generation. Higher doses (10-20 mg daily) are approved to treat and prevent venous thromboembolism, and prevent stroke or systemic embolism in patients with atrial fibrillation. Lower doses (2.5 mg twice daily), combined with antiplatelets, reduce cardiovascular mortality, myocardial infarction and stroke in patients with acute coronary syndromes or stable coronary artery disease.

The COMMANDER HF trial tested whether, compared to placebo, rivaroxaban 2.5 mg twice daily could reduce thrombin generation and thereby lower rates of death and cardiovascular events in patients with recent worsening of chronic heart failure, who had reduced ejection fraction (40% or less), coronary artery disease and no atrial fibrillation.

Professor Faiez Zannad, study author, University of Lorraine, Nancy, France, said: "COMMANDER HF is not just another trial of oral anticoagulation in heart failure. The aim is to interfere with disease processes that rely on thrombin using a targeted antithrombin drug."

The trial enrolled 5,022 patients from 628 sites in 28 countries. Patients were randomly assigned to rivaroxaban 2.5 mg, taken orally twice daily, or matching placebo. The use of guideline recommended therapies for heart failure and coronary artery disease was well balanced between groups and included diuretics, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers, and mineralocorticoid receptor antagonists. Background therapy included aspirin in virtually all patients and a substantial number were also receiving dual antiplatelet agents at the time either rivaroxaban or placebo was initiated in the trial.

The median age of participants at the start of the study was 66 years, 23% were women, and the median ejection fraction was 34%. Patients were followed-up for the primary efficacy outcome of all-cause mortality, myocardial infarction, or stroke. The primary safety outcome was the composite of fatal bleeding or bleeding into a critical space with a potential for permanent disability.

During a median follow-up of 21.1 months, the primary efficacy outcome occurred in 626 (25.0%) of 2,507 patients assigned to rivaroxaban compared to 658 (26.2%) of 2,515 on placebo (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.84-1.05, p=0.27). There were no differences between groups in all-cause mortality (HR 0.98, 95% CI 0.87-1.10, p=0.74) or nonfatal myocardial infarction (HR 0.83, 95% CI 0.63-1.08, p=0.17) but there was a significantly lower rate of nonfatal stroke in the rivaroxaban, compared to placebo, group (HR 0.66, 95% CI 0.47-0.95, p=0.023).

The principal safety outcome occurred in 18 (0.7%) patients assigned to rivaroxaban and 23 (0.9%) assigned to placebo (HR 0.80, 95% CI 0.43-1.49, p=0.48). Patients taking rivaroxaban had a significantly higher risk of major bleeding as defined by the International Society on Thrombosis and Haemostasis (ISTH) compared to those on placebo (HR 1.68, 95% CI 1.18-2.39, p=0.003). This result was mainly driven by the ISTH criterion of bleeding causing a fall in haemoglobin of 2 g/dL (1.24 mmol/L) or more.

Serious adverse events were reported in 479 (19.2%) patients taking rivaroxaban and 451 (18.0%) on placebo. The percentage of patients who permanently discontinued study medication due to an adverse event was 7.1% in the rivaroxaban group and 5.8% in the placebo group.

Professor Zannad said: "The most likely reason rivaroxaban failed to improve the primary efficacy outcome is that thrombin-mediated events are not the major driver of cardiovascular events in patients with recent heart failure hospitalisation. Whether a higher dose of rivaroxaban could have led to a more favourable result is unknown."

Biodiversity plays a significant role in forest carbon storage, but surprisingly less than previously thought, new research in Ecology Letters suggests.

By analyzing stores of carbon in temperate and boreal forests, researchers found that tree diversity does influence the amount of carbon stored in a given part of an ecosystem. But in a departure from previous research, researchers found biodiversity's role was relatively small when compared to other forest traits and environmental factors - and even can decrease carbon storage in some cases.

The research team, led by Carol Adair of the University of Vermont and David Hooper of Western Washington University, found that climate, site topography, time since fire, and characteristics of the tree species in each plot explained most of the variation in forest carbon storage across temperate and boreal forests in Québec, Canada. Alain Paquette of Université du Québec à Montréal and Bruce Hungate of Northern Arizona University co-authored the study.

The impacts of biodiversity on carbon storage were not trivial. It increased live tree carbon storage by up to 20 megagrams per hectare (Mg C per hectare), about one-third of the live tree carbon in an average forest (13% of total C) - or equal to the carbon in 8,500 gallons of gasoline. However, other factors had a much larger impact. For example, going from well- to poorly-drained sites increased the amount of carbon in undecomposed organic matter (leaves, twigs and branches) on the forest floor in an average forest by more than 400%.

Researchers also found that tree diversity did not have uniformly positive impacts on forest carbon storage. While biodiversity increased carbon stored in lived trees, it decreased carbon storage in forest floor organic matter by up to ~10 Mg C per hectare.

"These new findings indicate that ecosystem scientists should shift away from treating biodiversity as an assumed amplifier of key ecosystem services like carbon storage, and instead treat it as a subset of factors that influence such services," says Carol Adair of UVM's Rubenstein School and Gund Institute for Environment.

Instead of manipulating diversity in experimental plots in one location with a single soil type and climate, as some recent biodiversity studies have done, Adair and her team reviewed decades' worth of data collected from thousands of forest plots in Québec through the prism of a different question: what state factors and interactive controls affect carbon storage, and how important is species diversity among that suite of variables?

The well-inventoried Québec forests offered a trove of data to work with: the number of tree species, how many of each, and how big the trees in each plot were had all been documented. Scientists had counted how many trees were alive, or dead, and how much dead tree matter had accumulated on the surface of the soil. The researchers also analyzed climate, local topography and soil drainage, and when the last fire had swept through each plot.

Using a technique called structural equation modeling, which calculates the likelihood and strength of different causal relationships, the research team evaluated how different factors could explain the total amount of carbon in the plots.

The team found that forest traits and factors, such as tree size, climate conditions and time since last fire increased carbon storage more than diversity. In warmer regions, where trees grow faster and larger and accumulate more carbon, larger tree species, such as white spruce and maple, replaced smaller species like black spruce. Plots with topography that restricted water flow (low, swampy areas) stored more soil carbon, because soil microorganisms run out of oxygen in wet places and decomposition slows down. Plots that had burned more recently stored less carbon.

"This study is among the first to explicitly compare the effects of environmental factors with biodiversity in ecosystems outside of experimental plots." says David Hooper of Western Washington University. "The study also helps to integrate diversity - a relatively recent consideration as an ecosystem driver, with these other well-known factors. By integrating biodiversity into such a framework, ecologists can better ask when, where, why and how much diversity matters for ecosystem services that benefit society."

"Forest managers can focus on facets of tree diversity to increase live tree carbon, while acknowledging that a warming or drying climate may have much larger impacts," the researchers add. For example, if swampy forests become warm and dry, they could release three times as much carbon to the atmosphere as is stored in an average forest.

COLUMBUS, Ohio - Walleye and the fish they eat struggle to see in water clouded by algae, and that could potentially jeopardize the species' future if harmful algal blooms persist, according to a new study.

The research, led by Suzanne Gray of The Ohio State University, found that algae posed more of a threat to adequate vision than an equal amount of sediment - another common cause of murky waters in the western basin of Lake Erie.

The researchers found a decrease of more than 40 percent in the fishes' ability to see in water clouded by simulated algae as opposed to water equally clouded by sediment. The study appears in the journal Conservation Physiology.

For many fish, vision is the primary tool for survival, leading them to food and away from predators that want to eat them.

"This is concerning for these important fish populations. If we can't get a handle on algal blooms, this could threaten their well-being," said Gray, an assistant professor of aquatic physiological ecology at Ohio State.

The researchers placed individual fish - six juvenile walleye and 17 emerald shiner - in round tanks of water surrounded by a rotating screen with alternating black and white stripes. The screen moved around slowly and, in clear water, the fish would naturally identify the pattern and swim circles in time with the rotating stripes.

"It's an innate response for the fish to identify the difference between black and white and follow the screen," Gray said.

The researchers added increasing amounts of either sediment taken from Lake Erie or spinach (to mimic algae) to the tank. Emulsified spinach was used in this and a previous study because of its similarity in color, size and light-scattering properties to common algal bloom species.

After adding sediment or spinach, the researchers observed the behavior of the fish. When the fish stop following the moving stripes, they presumably can no longer see them, Gray said.

Though the amount of turbidity - a term scientists use to describe cloudiness in water - was equal with both substances, the fishes' response was not.

They were far better equipped to see in water made murky with sediment than in the green, cloudy water created with the addition of spinach.

"The difference was way more profound than I expected. You could make the water really muddy and they would keep on swimming round and round, but you only had to add a little 'algae' and they would just sit there," Gray said.

Increasing threats of harmful algal blooms in Lake Erie and in freshwater lakes and streams elsewhere are cause for widespread ecological concern, and it's important to understand how they could be impacting fish populations, Gray said.

"This isn't just an Ohio problem, it's a problem all around the world," she said.

The difference the researchers saw in this study may be because the fish have adapted to low-light vision (walleye hunt at dusk and dawn) in the intermittently muddy waters of the relatively shallow western basin of Lake Erie, she said.

"But algae is different. It's green and it changes the light. It could be that both the reduction in light and the change in color inhibits vision differently than sediment," Gray said.

Gray, who has studied fish around the world, became interested in walleye and the emerald shiner on which they feed not long after relocating to Ohio State.

It was 2014, and Toledo had just warned against drinking its water due to a major harmful algal bloom in Lake Erie that had found its way into the public water system.

"I saw an editorial cartoon showing an angler trying to fish in murky green water and saying something like 'Can the fish even see the bait on my hook?' and I thought that I could probably help answer that question," Gray said.

Munich, Germany - 26 Aug 2018: The use of an oral anticoagulant medicine in medically ill patients for 45 days following their discharge from the hospital reduces the rate of non-fatal symptomatic blood clots with no impact on fatal blood clots, according to late breaking results from the MARINER trial presented today in a Hot Line Session at ESC Congress 20181 and published in The New England Journal of Medicine.

Professor Alex Spyropoulos, study author, of the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, New York, US, said: "Anticoagulants help prevent blood clots in medically ill patients while they are under our supervision at the hospital. However, the risk of blood clots extends well beyond this period. Our results suggest we may be able to offer further protection to patients at risk from non-fatal blood clots, with no increase in major bleeding, by prescribing an oral anticoagulant for use after discharge. This study has potential to reduce the public healthcare burden of non-fatal blood clots in a large proportion of medically ill patients."

Each year, around 20 million acutely ill medical patients are hospitalised in the US and EU with conditions such as heart attack, pneumonia, flu, bronchitis, asthma, or broken bones. A significant proportion of these patients are at risk of venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism, while in hospital and up to six weeks afterwards. Around 70% of hospital-acquired fatal pulmonary embolism occurs in medically ill patients.

Anticoagulants delivered by intravenous drip or injection are recommended to prevent blood clots (called thromboprophylaxis) in medically ill patients while in hospital, but guidelines do not recommend any use of anticoagulants post-discharge. However, after leaving the hospital the rate of symptomatic VTE more than doubles over the first 21 days and is associated with a five-fold increased risk of fatal pulmonary embolism within 30 days post-discharge.

The MARINER trial2 investigated whether continuing thromboprophylaxis with an oral anticoagulant after discharge could reduce the risk of symptomatic VTE and VTE-related death in medically ill patients at risk for VTE. The trial enrolled 12,024 patients from 671 centres in 36 countries. Patients were 40 years of age or older, had been hospitalised for an acute medical illness, and had other risk factors for VTE as defined by a VTE risk score that included immobilisation for one day or longer, being in intensive care, age over 60 years, limb paralysis, previous VTE, thrombophilia or a D-dimer level more than two times the upper limit of normal.

Patients were randomly allocated to a 45-day course of either once daily oral rivaroxaban 10 mg (7.5 mg in patients with reduced kidney function) or placebo at the time of hospital discharge. The primary efficacy outcome was symptomatic VTE and VTE-related death. The principal safety outcome was major bleeding.

The final analysis included 12,019 patients, of whom 11,962 (99.5%) had taken at least one dose of study drug. The average age was 69.7 years and 48% were female. Four in ten patients had been admitted to hospital for heart failure, 27% for respiratory insufficiency, 17% for infectious disease, 14% for ischaemic stroke, and 2% for inflammatory disease.

During the 45-days post-discharge, 50 (0.83%) patients taking rivaroxaban had symptomatic VTE or died from VTE-related causes compared to 66 (1.1%) taking placebo (p=0.136). When examining symptomatic VTE only, which included lower extremity DVT and non-fatal pulmonary embolism, there were fewer events with rivaroxaban (0.18%) compared to placebo (0.42%; hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.22-0.89, p=0.023).

The researchers also examined an exploratory secondary composite endpoint of symptomatic VTE and all-cause mortality and found that 1.3% of patients taking rivaroxaban experienced an event compared to 1.78% of patients in the placebo group (HR 0.73, 95% CI 0.54-0.97, p=0.033).

Major bleeding occurred in 17 (0.28%) patients in the rivaroxaban group compared to nine (0.15%) taking placebo (p=0.124), with very few critical and fatal bleeds and no significant difference between groups.

Munich, Germany - Aug 26, 2018: Sleeping less than six hours or waking up several times in the night is associated with an increased risk of asymptomatic atherosclerosis, which silently hardens and narrows the arteries, according to results of the PESA study1 presented today at ESC Congress 2018.2

Dr Fernando Dominguez, study author, of the Spanish National Centre for Cardiovascular Research (CNIC) in Madrid, said: "Bad sleeping habits are very common in Western societies and previous studies have suggested that both short and long sleep are associated with an increased risk of cardiovascular disease. However, there is a lack of large studies that have objectively measured both sleep and subclinical atherosclerosis."

The PESA study enrolled 3,974 healthy middle-aged adults who wore a waistband activity monitor for seven days to record sleep quality and quantity. They were divided into five groups according to the proportion of fragmented sleep, and four groups designating average hours slept a night: less than six (very short), six to seven (short), seven to eight (the reference), and more than eight (long). Atherosclerosis was assessed in leg and neck arteries using three-dimensional ultrasound.

The average age of participants was 46 years and 63% were men. After adjusting for conventional cardiovascular risk factors and potential confounding factors, including age, gender, moderate to vigorous physical activity, body mass index, smoking status, alcohol consumption, blood pressure, education level, blood glucose levels, total cholesterol, total calorie consumption per day, marital status, stress and depression questionnaire scores and obstructive sleep apnoea risk (STOP-BANG score), very short sleepers had significantly more atherosclerosis than those who got seven to eight hours (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.06-1.52, p=0.008) (see figure).

Those in the highest quintile of fragmented sleep were more likely to have multiple sections of arteries with atherosclerosis compared to those in the lowest quintile (OR 1.34, 95% CI 1.09-1.64, p=0.006) (figure).

Dr Dominguez said: "People who had short or disrupted sleep were also more likely to have metabolic syndrome, which refers to the combination of diabetes, high blood pressure, and obesity, and depicts an unhealthy lifestyle."

He concluded: "Failure to get enough sleep and restlessness during the night should be considered risk factors for blocking or narrowing of the arteries. Studies are needed to find out if sleeping well and long enough can prevent or reverse this effect on the arteries. In the meantime it seems sensible to take steps to get a good night's sleep - such as having a physically active lifestyle and avoiding coffee and fatty foods before bedtime."

Oxygen therapy does not prevent the development of heart failure. Neither does it reduce the long-term risk of dying for patients with suspected heart attack. This has been proven for the first time by researchers at Karolinska Institutet as a result of a major Swedish study. The study is to be presented at the European Society of Cardiology's (ESC) cardiology congress in Munich and published at the same time in the journal Circulation. The researchers expect their results to have a global impact on recommended healthcare for treating heart attacks.

Oxygen has been used to treat patients suffering a heart attack for more than a century, despite the fact that such treatment has not had any scientifically proven effect on patients who have normal oxygen levels in their blood. Since the turn of the millennium, researchers worldwide have started to question whether oxygen therapy for heart attacks is ineffective - or may even be harmful.

"Our new study has filled a central gap in knowledge regarding how to treat patients suffering a heart attack. One year ago, we were able to confirm that oxygen therapy does not appear to reduce the risk of dying up to one year after the heart attack. We can now substantiate these findings for a long-term perspective and show that oxygen therapy does not reduce the development of heart failure, the most worrying complication of heart attacks. On this basis, the routine use of oxygen can now be eliminated, and healthcare personnel can concentrate on more efficient measures and rapid transport to hospital," confirms Robin Hofmann, senior consultant cardiologist and researcher at the Department of clinical science and education, Södersjukhuset, at Karolinska Institutet.

The DETO2X-AMI study was conducted at 35 Swedish hospitals, involving random treatment with or without oxygen of 6,629 patients with suspected heart attack. The result shows that oxygen therapy in a moderate dose is not harmful but does not increase the survival rates or reduce complications, such as the development of heart failure or new heart attacks.

The research project was financed by the Swedish Heart-Lung Foundation and the Swedish Research Council.

Munich, Germany - UNDER EMBARGO UNTIL 25 Aug 2018: New advice on the choice between open heart surgery and inserting a stent via a catheter after a heart attack is launched today. The European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS) Guidelines on myocardial revascularization are published online in European Heart Journal1, and on the ESC website.2

Coronary artery disease, also called ischaemic heart disease, is the top cause of death worldwide. Arteries supplying oxygen-rich blood to the heart become narrowed with fatty material, causing chest pain and increasing the risk of heart attacks and death. Patients should stop smoking, be physically active, and consume a healthy diet. They also need lifelong medication which can include a statin to control blood lipids, blood pressure lowering drugs, and aspirin.

Myocardial revascularization can be performed in patients with stable (chronic) coronary artery disease or an acute event (heart attack) to improve blood flow to the heart, reduce chest pain (angina), and improve survival. There are two types of myocardial revascularization: open heart surgery to bypass clogged arteries (coronary artery bypass grafting; CABG) and percutaneous coronary intervention (PCI) to open clogged arteries with a stent.

Patients should be involved in choosing the procedure, state the guidelines. They need unbiased, evidence-based information with terminology they can understand explaining the risks and benefits in the short- and long-term such as survival, relief of chest pain, quality of life, and requirement for a repeat procedure. In non-emergency situations, patients must have time to reflect on the trade-offs and seek a second opinion. Patients have the right to obtain information on the level of experience of the doctor and hospital in performing these procedures.

Outcomes from the two procedures vary according to the anatomical complexity of coronary artery disease. This is graded using the SYNTAX Score, which predicts whether PCI can provide similar survival as bypass. For patients with more simple disease, surgical bypass and PCI provide similar long-term outcomes. For patients with complex disease, long-term survival is better with surgical bypass. Also, patients with diabetes have better long-term outcomes with surgical bypass even with less complex disease.

A heart team of cardiologists, cardiac surgeons and anaesthetists should be consulted for patients with chronic coronary artery disease and a complex coronary anatomy, while respecting the preferences of the patient.

Professor Miguel Sousa-Uva, EACTS Chairperson of the Guidelines Task Force, Santa Cruz Hospital, Carnaxide, Portugal, said: "Despite the development of new stents, studies show that patients with complex coronary artery disease have better survival with bypass surgery and this should be the preferred method of revascularization."

In patients with stable disease, another aspect to consider when choosing the procedure is whether it is possible to bypass or insert a stent into all blocked arteries, as this improves symptoms and survival. Preference should be given to the procedure most likely to achieve this so-called complete revascularization.

When PCI is chosen, stents that release a drug to prevent clots, heart attacks, and reinterventions should be used in all procedures. Bioresorbable stents, which are absorbed by the body, should only be used in clinical trials.

Professor Franz-Josef Neumann, ESC Chairperson of the Guidelines Task Force, University Heart Centre Freiburg ? Bad Krozingen, Germany, said: "The guidelines aim to help patients and doctors make a logical decision on the type of revascularization based on the scientific evidence. They will also be consulted by governments and health insurers as the standard of care for coronary artery disease."

Munich, Germany - 25 Aug 2018: A smartphone application (app) can help in screening for atrial fibrillation, according to late breaking results from the DIGITAL-AF study presented today at ESC Congress.1

Professor Pieter Vandervoort, principal investigator, of the University of Hasselt, Belgium, said: "Most people have a smartphone with a camera which is all they need to detect atrial fibrillation. This is a low cost way to screen thousands of people for a condition which is becoming more prevalent and can have serious consequences unless treated."

Atrial fibrillation is the most common heart rhythm disorder. One in four middle-aged adults in Europe and the US will develop atrial fibrillation.2 It causes 20-30% of all strokes and raises the risk of premature death, but outlook improves dramatically with oral anticoagulation therapy. Undiagnosed atrial fibrillation is common and many patients remain untreated. Opportunistic screening is recommended in over-65s, but has time, logistical, and resource demands.

DIGITAL-AF examined the feasibility and effectiveness of screening for atrial fibrillation with a smartphone app medically certified in the EU to detect the condition. The app was made freely available by publishing an access token in a local newspaper. Within 48 hours, 12,328 adults had scanned the token and enrolled in the study.

Participants were instructed to use their own smartphone to measure their heart rhythm twice a day for one week. If they had symptoms such as heart palpitations, shortness of breath or fatigue they were advised to input them into the app. The app is used by holding the left index finger in front of the smartphone camera for one minute, during which photoplethysmography measures the heart rhythm.

Heart rhythm measurements were automatically classified as regular rhythm, possible atrial fibrillation, other irregular rhythm, or insufficient quality. Measurements indicating atrial fibrillation or other irregular rhythms were reviewed by medical technicians experienced in analysing photoplethysmography signals, under the supervision of cardiologists.

All participants received an automatically generated report on their smarphone with a copy of their rhythm traces and an interpretation. Those with atrial fibrillation or other irregular rhythms were advised to see their doctor. Four months later, all participants who had at least one measurement showing atrial fibrillation received a follow-up questionnaire by e-mail about actions they had taken as a result of the screening programme.

The average age of the screened population was 50 years and 58% were male. A total of 9,889 (80%) participants had regular (sinus) rhythm, 136 (1.1%) had atrial fibrillation, 2,111 (17%) had other irregular rhythms, and 191 (2%) had measurements of insufficient quality for analysis.

The average age of the atrial fibrillation group was 63 years, and seven in ten were men. Three-quarters had no symptoms. Regarding the type of atrial fibrillation, in 38 patients (28%) it was "persistent or permanent" and detected on the first measurement, and in 98 (72%) it was "paroxysmal", of which 13 cases were detected on the first measurement. (see figure 1)

The questionnaire was completed by 100 out of 136 atrial fibrillation patients. It showed that 40 patients had a new diagnosis, of which 21 (53%) consulted a doctor for confirmation. Sixty patients had been previously diagnosed, of whom 17 (28%) had their treatment adjusted after seeing a doctor. (see figure 2)

Professor Vandervoort said: "The verification of diagnoses by medical technicians showed that interpretations by the app were very accurate, suggesting that this step could be significantly downsized and possibly omitted from a screening programme. According to our study approximately 225 people would need to be screened to detect one new atrial fibrillation diagnosis. This is an acceptable return, given the low cost."

Professor Vandervoort noted that smartphones are becoming popular in older age groups, which are more susceptible to atrial fibrillation. He said: "This technology has real potential to find people with previously unknown atrial fibrillation so they can be treated."

First, according to Rice University engineers, get a nanotube hole. Then insert water. If the nanotube is just the right width, the water molecules will align into a square rod.

Rice materials scientist Rouzbeh Shahsavari and his team used molecular models to demonstrate their theory that weak van der Waals forces between the inner surface of the nanotube and the water molecules are strong enough to snap the oxygen and hydrogen atoms into place.

Shahsavari referred to the contents as two-dimensional "ice," because the molecules freeze regardless of the temperature. He said the research provides valuable insight on ways to leverage atomic interactions between nanotubes and water molecules to fabricate nanochannels and energy-storing nanocapacitors.

A paper on the research appears in the American Chemical Society journal Langmuir.

Shahsavari and his colleagues built molecular models of carbon and boron nitride nanotubes with adjustable widths. They discovered boron nitride is best at constraining the shape of water when the nanotubes are 10.5 angstroms wide. (One angstrom is one hundred-millionth of a centimeter.)

The researchers already knew that hydrogen atoms in tightly confined water take on interesting structural properties. Recent experiments by other labs showed strong evidence for the formation of nanotube ice and prompted the researchers to build density functional theory models to analyze the forces responsible.

Shahsavari's team modeled water molecules, which are about 3 angstroms wide, inside carbon and boron nitride nanotubes of various chiralities (the angles of their atomic lattices) and between 8 and 12 angstroms in diameter. They discovered that nanotubes in the middle diameters had the most impact on the balance between molecular interactions and van der Waals pressure that prompted the transition from a square water tube to ice.

"If the nanotube is too small and you can only fit one water molecule, you can't judge much," Shahsavari said. "If it's too large, the water keeps its amorphous shape. But at about 8 angstroms, the nanotubes' van der Waals force starts to push water molecules into organized square shapes."

He said the strongest interactions were found in boron nitride nanotubes due to the particular polarization of their atoms.

Shahsavari said nanotube ice could find use in molecular machines or as nanoscale capillaries, or foster ways to deliver a few molecules of water or sequestered drugs to targeted cells, like a nanoscale syringe.