Earth

Australian researchers looking for a genetic lifeline to endangered hog deer species endemic to Pakistan, northern India and mainland southeast Asia have found widespread hybridisation of the species in Victoria.

The La Trobe led study, partially funded by the Game Management Authority and published recently in Ecology and Evolution, has revealed hog deer introduced to Victoria in the 1860s are comprised entirely of hog deer and chital hybrids within the Gippsland region.

Lead researcher Erin Hill, from the School of Life Sciences at La Trobe University, said the study is the first to show hog deer in Victoria are hybrids.

"Exactly when the hybridisation occurred is unknown. It may have occurred in their native range, in captivity prior to release, or following release in Victoria, as chital deer were introduced at about the same time," Ms Hill said.

"We examined and sequenced the genetic makeup of 80 deer in Victoria and found no trace of pure hog deer living in the wild.

Associate Professor Jan Strugnell, from James Cook University, also an author on the study, said that established chital populations in Australia only exist in pockets in Queensland and New South Wales.

"Given chital species were eradicated in Victoria almost 100 years ago, it's clear this hybrid species has survived over generations because it is fertile."

Ms Hill said that the discovery of widespread hybridisation could affect the management of hog deer in Victoria.

"This is due to the long-held belief that this introduced species could play an essential role in the conservation of the species throughout its native range," Ms Hill said.

"Victoria is home to one of the few remaining stable populations of hog deer left in the world."

Ms Hill said it is vital to stress the importance of the introduced species for conservation, despite their newly discovered hybrid status.

"Our study has revealed that translocations of introduced Victorian deer back into the native range would likely need to be restricted to areas where hog deer and chital co-exist naturally," Ms Hill said.

"This would include the northern regions of India, where native chital and hog deer are endangered due to overhunting and habitat loss."

Ms Hill said more research is needed before translocations can occur.

"The next steps are to assess the hybridisation rate of hog deer and chital within the native range in India, and to further explore the idea of translocating Victorian hog deer back to the native range by measuring the levels of genetic variation within the Victorian population," Ms Hill said.

"Genetic variation is important as it allows individuals to adapt to their environment, and so it is important to reintroduce as much genetic variation as possible back into the native range to ensure long-term survival of the species."

Palorchestid marsupials, an extinct group of Australian megafauna, had strange bodies and lifestyles unlike any living species, according to a study released September 13, 2019 in the open-access journal PLOS ONE by Hazel Richards of Monash University, Australia and colleagues.

For most of the last 25 million years, eastern Australia was home to a now-extinct group of marsupials called palorchestids. These animals are well known for their large size, strange tapir-like skulls, and large claws, but so far there has been no detailed study of their limb morphology. In this study, Richards and colleagues examined more than 60 fossil specimens of palorchestids of varying geologic ages to characterize the function and evolution of their arms and legs.

Over the course of their evolution, palorchestids grew larger and stranger. Using limb proportions as a proxy for body size, these authors estimated that the latest and largest of the palorchestids may have weighed over 1,000kg. Furthermore, their forelimbs were extremely muscular and were likely adapted for grabbing or scraping at leaves and branches. Uniquely among known mammals, the elbow joints of the largest palorchestids appear to have been immobile and fixed at roughly a 100-degree angle, so that the arms served as permanently flexed food-gathering tools.

This study provides the first formal description of limb morphology in palorchestid marsupials and reveals a group of giant herbivores that probably filled a niche no longer occupied in modern Australian ecosystems. Fossil remains are still missing for certain parts of the palorchestid body, such as the shoulders and wrists, but the authors are hopeful that more material may be found in existing museum collections.

The authors add: "This study has allowed us for the first time to appreciate just how huge these mega-marsupial palorchestids were, while also providing the first comprehensive view of a strange limb anatomy unprecedented in the mammalian world. This research reveals yet more about the diversity of unique large marsupials that once roamed Australia not so long ago."

Technology is getting smaller - which is good news.

The ability to fabricate materials with optical, electrical and mechanical properties out of very small particles could have far-reaching applications. For example, micro-particles grafted with DNA can be used in medicine for better sensing, imaging and treatment delivery. An improved understanding of how these materials behave could lead to fulfilling the promise of precision medicine, among other applications.

There is still much to learn about how best to direct the fabrication of these micro-materials. The self-assembly process of DNA-functionalized micro-sized particles leads to crystallization, i.e., atoms and molecules transforming into a highly-structured form called a crystal. Crystallization begins with nucleation - the process by which atoms or molecules cluster together on the microscopic scale. If the clusters become stable and large enough, crystal growth may occur. Atoms and compounds can generally form more than one crystal structure, called polymorphism. The arrangement of particles is determined during the early stages of crystallization.

According to Jeetain Mittal, a professor of chemical and biomolecular engineering at Lehigh University, structural transformations that involve the potential for polymorphism during crystallization have conventionally been attributed to kinetic effects, or the rate of nucleation, to predict what structures may be observed when crystals form. This is line with classical nucleation theory.

Now, Mittal and his team have shown that kinetic effects may be unable to fully explain structural transformation in all polymorphic situations and that surface thermodynamics - related to crystallite size as opposed to rate - can be critical for driving transformations between crystal structures. The team found a new pathway for structural transformation from square to hexagonal lattice during crystal growth which is thermodynamically-driven.

In many previous systems, according to Mittal, the crystallites exhibiting structural polymorphism have been attributed to kinetic effects, related to nucleation rate. In their work, Mittal and his collaborators provide solid calculation to demonstrate the structural transformation can be entirely thermodynamic, in contrast to the kinetic argument, from both theoretical and computational perspectives. Further, a similar structural transformation is observed in a more detailed modeled system using a coarse-grained model representing DNA functionalized particle. This is strong evidence that such structural transformations can be much more general and can be connected back to more realistic systems.

"Understanding the crystallization process is especially important for controlling and predicting the structure produced," says Runfang Mao, a current Lehigh PhD student and co-author on the paper. "Though useful in many cases, classical nucleation theory is understood to be invalid in many systems. We show that such size-dependent structural transformation is one of those exceptions, and that it is driven by thermodynamic properties of finite-sized crystallites. To our knowledge, such size-dependent structural transformation has not been clearly illustrated elsewhere in the literature."

Their findings have been published today in Science Advances in the article "Size-dependent thermodynamic structural selection in colloidal crystallization." In addition to Mittal and Mao, authors include Evan Pretti, Hasan Zerze, Minseok Song and Yajun Ding - all current or former students in Lehigh's
P.C. Rossin College of Engineering and Applied Science.

Mittal and his team studied how particular mixtures of colloids with DNA strands tethered to their surfaces crystallize into two-dimensional lattices as the colloids interact with each other. Crystallization, as Pretti explains, begins from small clusters of particles which grow and aggregate, and under certain conditions, these crystallites can start in one crystal structure and transform into another as time passes.

"We find that, for our system, these transformations can be explained based on how the relative thermodynamic stabilities of the different structures is affected by the crystallites' sizes," says Pretti. " In particular, for small enough crystallites, the thermodynamics of the surfaces become important enough that they can influence the structure, which triggers the observed transformations during self-assembly."

According to Mittal, these DNA-functionalized systems are of particular interest in the field of colloidal assembly, because of the great flexibility and variety of possibilities afforded by using different kinds of particles and sequences of DNA. Their results, however, are not limited just to such systems, but could provide a greater understanding of how other kinds of crystallization processes work and can be controlled.

The team started using standard molecular dynamics simulations to understand how their system behaved. To prove that the transformations they were seeing were of a thermodynamic origin, they took an existing method used to calculate relative thermodynamic stabilities of periodic crystalline solids, and modified it so that they could analyze their finite-sized crystallites.

"We have identified a structural transformation which is reversible and can be explained using only the thermodynamics of the finite-sized crystals themselves," says Mittal. "Our work can provide a new way to look at and explain transformations in DNA-functionalized particle systems and potentially also in other kinds of crystals."

WESTMINSTER, Colorado - September 13, 2019 - A research study featured in the journal Weed Science provides worrisome new details about the evolution of herbicide resistance in waterhemp - an annual weed that represents a significant threat to Midwest corn and soybean crops.

When a waterhemp biotype in eastern Nebraska survived a post-emergent application of the PPO inhibitor fomesafen, a team of university scientists decided to take a close look. They discovered the population was resistant to four distinct herbicide sites of action, including PPO inhibitors, ALS inhibitors, EPSPS inhibitors and PS II inhibitors.

Among their findings:

All samples of the resistant waterhemp biotype tested positive for an ?G210 mutation in the PPX2L gene.

The population exhibited a four- to six-fold resistance to PPO-inhibiting herbicides,
a three-fold resistance to EPSPS inhibitors (glyphosate) and a seven-fold resistance to atrazine (a PS II inhibitor).

When the ALS inhibitors chlorimuron and imazethapyr were applied at 32 times the label application rate, they achieved a less than 80 percent reduction in the aboveground biomass of the resistant waterhemp biotype.

"Our study showed there simply are no effective post-emergent herbicide choices for the control of resistant waterhemp in either glyphosate-resistant or conventional crops," said Debalin Sarangi, a postdoctoral researcher at the University of Nebraska-Lincoln. "Growers will need to diversify their approaches to weed management and complement the use of chemicals with cultural and mechanical controls."

Researchers from the University of Copenhagen have studied what it means for children to have parents who are refugees and have PTSD. The study shows that these children have a significantly higher risk of contact with the psychiatric system. The researchers believe that there should be focus on the problem and that early measures and treatment options should be developed.

Post-traumatic stress syndrome (PTSD) is a delayed response to trauma and is often seen in refugees fleeing war and conflict. Now, in a large register study, researchers from the University of Copenhagen have studied the significance for children of having parents who are refugees and have been diagnosed with PTSD.

They have looked at whether children of refugees with PTSD are in more contact with the psychiatric system than children of refugees who do not have PTSD. The study shows that children with one or two parents who suffer from PTSD have a significantly higher risk of psychiatric contact. The new research results are published in the scientific journal Lancet Public Health.

'The results of the study indicate that there is a group of children and adolescents who are at increased risk of morbidity. You often focus on the traumatised parents, but it is also important to pay attention to the consequences which the parents' trauma may have for the whole family so that you do not disregard a group of children and young people who also need help'.

'This does not just apply to children who have fled to Denmark and may themselves be traumatised by war. We also see an increased risk in children born in Denmark,' says co-author on the study and Master in Public Health Maj Back Nielsen, the Department of Public Health.

75 Per Cent Higher Risk

PTSD can cause insomnia, nightmares, flashbacks and memory and concentration difficulties. In the study, the researchers show that if both parents had PTSD, their children were 75 per cent more likely to be in contact with the psychiatric system before they turned 18.

If it was just the mother, they had a 55 per cent higher risk, while the number was 49 per cent if only the father had PTSD - irrespective of whether the children themselves had fled to Denmark or were born here.

'We know that PTSD has a big effect on the daily ability to function. And having a PTSD diagnosis affects the dynamics of the whole family. It is important to emphasise that these are not bad parents, but due to their disorder, they are stressed and have some other conditions for being a parent and be there for their children.'

'It is an already vulnerable group which may be further stressed by uncertainties about temporary residency and other socio-economic conditions, such as finances. We know from other research that social conditions are linked to diseases,' says Professor and co-author of the study Marie Louise Nørredam, the Department of Public Health Sciences.

Dark Figures Cannot be Excluded

The researchers have analysed data from refugees who came to Denmark in the period from January 1995 to December 2015 and have been granted a residence permit. In total, they have analysed data from 51,793 children of refugees and their contact with the psychiatric system.

Contact with the psychiatric system means that the child has had contact with the system at hospital level, on an outpatient basis or as inpatient at a hospital. The researchers did not have access to information from general practitioners and e.g. practicing psychiatric therapists. Therefore, they cannot rule out that there are dark figures and that the number of children who have been in contact with the psychiatric system is higher.

The psychiatric disorders most commonly seen in children of parents with PTSD were behavioural and emotional disorders, nervous disorders and developmental disorders.

'If we want to ensure that these children have a proper future and opportunities in our community, we have to do something. Both the number of children and parents may be underestimated. Thus, there is a need for greater focus on the problem and on how we may take precautions and secure an earlier detection and develop early measures and treatment options for the children and their families,' says Marie Louise Nørredam.

EAST LANSING, Mich. - Healthy cells in our body release nano-sized bubbles that transfer genetic material such as DNA and RNA to other cells. It's your DNA that stores the important information necessary for RNA to produce proteins and make sure they act accordingly.

These bubbly extracellular vesicles could become mini treatment transporters, carrying a combination of therapeutic drugs and genes that target cancer cells and kill them, according to new research from Michigan State University and Stanford University.

The study, which focused on breast cancer cells in mice, is published in Molecular Cancer Therapeutics.

"What we've done is improve a therapeutic approach to delivering enzyme-producing genes that can convert certain drugs into toxic agents and target tumors," said Masamitsu Kanada, lead author and an assistant professor of pharmacology and toxicology in MSU's Institute for Quantitative Health Science and Engineering.

These drugs, or prodrugs, start out as inactive compounds. But once they metabolize in the body, they're immediately activated and can get to work on fighting everything from cancer to headaches. Aspirin is an example of a common prodrug.

In this case, researchers used extracellular vesicles, or EVs, to deliver the enzyme-producing genes that could activate a prodrug combination therapy of ganciclovir and CB1954 in breast cancer cells. Minicircle DNA and regular plasmid - two different gene vectors that act as additional delivery mechanisms for DNA - were loaded into the vesicles to see which was better at helping transport treatment. This is known as a gene-directed enzyme, prodrug therapy.

They found that the minicircle DNA was 14 times more effective at delivery and even more successful at killing cancerous tumors.

"Interestingly, the plasmid delivery method didn't show any tumor cell killing," Kanada said. "Yet the minicircle DNA-based therapy killed more than half of the breast cancer cells in the mice."

According to Kanada, this new approach could effectively become a better cancer treatment option than chemotherapy down the road.

"Conventional chemotherapy isn't able to differentiate between tumors and normal tissue, so it attacks it all," Kanada said. "This non-specificity can cause severe side effects and insufficient drug concentration in tumors."

With EVs, treatment can be targeted and because of their compatibility with the human body, this type of delivery could minimize the risk of unwanted immune responses that can come with other gene therapies.

"If EVs prove to be effective in humans, it would be an ideal platform for gene delivery and it could be used in humans sooner than we expect," Kanada said.

A phase-one clinical trial, separate from Kanada's work, is set to start soon in the U.S. and will use EVs and a type of therapeutic RNA molecule for the treatment of metastatic pancreatic cancer.

While that trial moves forward, Kanada and his team will continue to further engineer and test EVs, improving their effectiveness and safety so using them as a cancer-fighting gene therapy in humans becomes reality.

Land restoration in Latin America and the Caribbean is picking up pace and scaling up projects will help the region meet its pledges under the Bonn Challenge, which aims to restore 350 million hectares of degraded and deforested land worldwide by 2030. A new study led by the International Center for Tropical Agriculture (CIAT) and Wageningen University supplies a first map of restoration projects in Latin America and shows their potential to mitigate climate change through restoring forests.

Researchers took stock of the location, goals and activities of 154 projects in Latin America and the Caribbean, starting a database to guide practitioners in scaling up restoration. They mapped projects under five initiatives working towards the Bonn Challenge goals - the 20x20 Initiative, the Global Environment Facility, the Clean Development Mechanism (CDM), the Forest Investment Program (FIP) and independent local projects - in tandem with mapping the potential biomass increase that forest restoration could achieve across the region's various ecosystems.

"We're asking a lot from the land, to produce food for another couple of billion people. We also don't want to lose more forest," said co-author Louis Verchot, a researcher at CIAT and a leading contributor to the Intergovernmental Panel on Climate Change (IPCC)'s recent Climate Change and Land report. "We need to make more out of the land that we have. The IPCC 1.5 °C report made clear how fast we need to take carbon out of the atmosphere. To do that, you have to do something about land emissions."

In Latin America many of the ongoing or planned projects are in regions where there is high potential for increased biomass, such as the tropical and subtropical forest ecosystems on the edges of the Amazon Basin, Southeast Brazil and Central America. While all projects can provide more forest biomass for carbon sequestration, results show that CDM, FIP and local projects have the biggest capacity to do so. Local level projects also focused on areas with high carbon sequestration potential, and CDM projects focused on forestry plantation efforts. Projects associated with the initiative 20x20 pursued a diverse set of goals in a wider range of landscapes and was less focused on carbon sequestration.

While all projects mainly aim to increase vegetation cover, recover biodiversity and ecosystem services, restoration takes many faces across Latin America, which impacts how much carbon a restored area will be able to capture, the study shows. Natural regeneration is the most popular choice for restoring vegetation, along with assisted regeneration and mixed plantations. GEF, FIP and local restoration projects preferred this low-cost, high-carbon sink approach, point out the researchers. These "may contribute widely to climate change mitigation," the study says.

"Natural regeneration is a cost-effective restoration method," said Verchot, who is part of the Agroecosystems and Sustainable Landscapes research team at CIAT. "You don't have to invest in seedling production and plantations. On the other hand, you get what you get. In degraded lands you get pioneer species, it might take decades to get back the pre-disturbed mix of species."

The study is the latest on the topic by Verchot and colleagues, including a paper published earlier this year that created a typology of land restoration in Latin America and the Caribbean. The study categorized three main restoration types, with the main defining variables being project area under restoration, amount of funding received, source of funding and monitoring efforts.

Drylands out of the restoration spotlight

Only 25 percent of restoration projects surveyed in Latin America focus on degraded drylands, the research shows, despite their exposure to desertification, loss of biodiversity, food insecurity and climate change. Visualizing the region's potential for more carbon-storing vegetation can help project developers spot which degraded drylands are in need of restoration. Donors and funding mechanisms that finance the projects have a big say on the goals and activities, the study says.

"A diversity of projects and initiatives will contribute towards achieving the aims of the Bonn Challenge and restore large amounts of degraded land," conclude the authors. But to be successful, we need to tackle the problem at its source. Large-scale restoration projects first need to understand what drives deforestation and forest degradation, as well as the ecological and social climate in which they happen, so that we better manage our lands and avoid the need to restore them in the future.

CATONSVILLE, MD, September 13, 2019 -There are more than 60 million business pages on Facebook and that number is from 2017. With those pages come scores of positive and negative posts generated by Facebook users. What researchers have seen is companies have very little control over what customers post, and negative posts can severely damage brands.

New research in the INFORMS journal Information Systems Research analyzes this user-generated content to understand the impact of what users post and how it impacts the brand. Engagements depend not only on the type of post, but also in the specific ways the post is positive or negative.

The study, conducted by Mochen Yang, Yuqing Ren, and Gediminas Adomavicius, all from the University of Minnesota, looks at data from 12,000 posts from 41 Fortune 500 companies in 6 industries in 2012.

The researchers found users on Facebook post substantially more negative than positive posts on business pages. The ratio is nearly 2 to 1.

"We also found positive and negative posts get more likes than neutral ones, but negative posts get the most comments," said Yang, a professor in the Carlson School of Management at the University of Minnesota. "Complaints about social issues receive more likes, but fewer comments, than complaints about quality or money issues."

Many companies went into the new territory of social media marketing with little understanding of user behaviors in this context. Whereas, online reviews provide structured feedback in the form of ratings and descriptions of products to inform other consumers' purchase decisions, this study illustrates the open-ended expressions in user-generated content. These people have a wider variety of goals that are not necessarily purchase-oriented.

"Though increased engagement has been linked to increases in brand loyalty, purchase expenditures, and profitability, companies should carefully consider whether Facebook business pages are an appropriate venue to interact with customers," said Yang. "And have a strategy in place to respond to negative posts because they tend to attract more attention than positive or neutral ones."

Researchers at EMBL's European Bioinformatics Institute and the Medical University of Vienna have found evidence that B cells might play an important role in immunotherapy for melanoma. Currently, immunotherapy is primarily focused on T cells, but the results suggest that B cells could also provide an interesting research avenue.

Immunotherapy is a form of cancer treatment that uses the body's own immune system to recognise and fight the disease. It comes in a variety of forms, including cancer vaccines, targeted antibodies or tumour-infecting viruses. Only some cancer patients currently benefit from this kind of therapy.

In the case of melanoma, which is a particularly aggressive form of skin cancer, established immunotherapies focus on T cells. T cells play an important role in controlling and shaping the immune system and they are able to directly kill cancer cells, while also recruiting other cells into the process.

A recent study published in Nature Communications has shown that, alongside T cells, B cells play a critical role in triggering melanoma-associated inflammation. B cells are a type of white blood cell, which can produce antibodies along with several important messenger molecules. The researchers found that, in the case of melanoma, B cells act almost like a satnav, directing T cells to the tumour via the secretion of such distinct messenger molecules.

"Immunotherapy has transformed cancer treatment," explains Johannes Griss, Researcher at the Medical University of Vienna and EMBL-EBI. "It unleashes T cells so they can fight cancer in a more effective way. For the first time, we found that B cells also play an important part in the process and help T cells find the tumour. The role of B cells in immunotherapy is still largely unknown, but it seems they may have more impact than previously thought."

During the study, the researchers observed that when B cells were depleted from melanoma patients, the number of T cells and other immune cells dramatically decreased within the tumours as well. In subsequent experiments, the researchers showed that a special subtype of B cells seems to be responsible for guiding T cells and other immune cells to the tumour.

Interestingly, melanoma cells seem to force B cells to develop into this distinct B cell subtype. Most excitingly, this specific B cell subtype also increased the activating effect of current immune therapies on T cells, and higher numbers of this B cell subtype in tumours before therapy predicted that a patient would respond better to subsequent immunotherapy.

"Further research is required to answer questions such as how melanoma cells modify B cells, what mechanism B cells use to support the activation of T cells, and how we can help these B cells to support current immunotherapies in cancer patients," concludes Griss.

CAMBRIDGE, MA -- With apologies to "Spinal Tap," it appears that black can, indeed, get more black.

MIT engineers report today that they have cooked up a material that is 10 times blacker than anything that has previously been reported. The material is made from vertically aligned carbon nanotubes, or CNTs -- microscopic filaments of carbon, like a fuzzy forest of tiny trees, that the team grew on a surface of chlorine-etched aluminum foil. The foil captures more than 99.96 percent of any incoming light, making it the blackest material on record.

The researchers have published their findings today in the journal ACS-Applied Materials and Interfaces. They are also showcasing the cloak-like material as part of a new exhibit today at the New York Stock Exchange, titled "The Redemption of Vanity."

The artwork, a collaboration between Brian Wardle, professor of aeronautics and astronautics at MIT, and his group, and MIT artist-in-residence Diemut Strebe, features a 16.78-carat natural yellow diamond, estimated to be worth $2 million, which the team coated with the new, ultrablack CNT material. The effect is arresting: The gem, normally brilliantly faceted, appears as a flat, black void.

Wardle says the CNT material, aside from making an artistic statement, may also be of practical use, for instance in optical blinders that reduce unwanted glare, to help space telescopes spot orbiting exoplanets.

"There are optical and space science applications for very black materials, and of course, artists have been interested in black, going back well before the Renaissance," Wardle says. "Our material is 10 times blacker than anything that's ever been reported, but I think the blackest black is a constantly moving target. Someone will find a blacker material, and eventually we'll understand all the underlying mechanisms, and will be able to properly engineer the ultimate black."

Wardle's co-author on the paper is former MIT postdoc Kehang Cui, now a professor at Shanghai Jiao Tong University.

Into the void

Wardle and Cui didn't intend to engineer an ultrablack material. Instead, they were experimenting with ways to grow carbon nanotubes on electrically conducting materials such as aluminum, to boost their electrical and thermal properties.

But in attempting to grow CNTs on aluminum, Cui ran up against a barrier, literally: an ever-present layer of oxide that coats aluminum when it is exposed to air. This oxide layer acts as an insulator, blocking rather than conducting electricity and heat. As he cast about for ways to remove aluminum's oxide layer, Cui found a solution in salt, or sodium chloride.

At the time, Wardle's group was using salt and other pantry products, such as baking soda and detergent, to grow carbon nanotubes. In their tests with salt, Cui noticed that chloride ions were eating away at aluminum's surface and dissolving its oxide layer.

"This etching process is common for many metals," Cui says. "For instance, ships suffer from corrosion of chlorine-based ocean water. Now we're using this process to our advantage."

Cui found that if he soaked aluminum foil in saltwater, he could remove the oxide layer. He then transferred the foil to an oxygen-free environment to prevent reoxidation, and finally, placed the etched aluminum in an oven, where the group carried out techniques to grow carbon nanotubes via a process called chemical vapor deposition.

By removing the oxide layer, the researchers were able to grow carbon nanotubes on aluminum, at much lower temperatures than they otherwise would, by about 100 degrees Celsius. They also saw that the combination of CNTs on aluminum significantly enhanced the material's thermal and electrical properties -- a finding that they expected.

What surprised them was the material's color.

"I remember noticing how black it was before growing carbon nanotubes on it, and then after growth, it looked even darker," Cui recalls. "So I thought I should measure the optical reflectance of the sample.

"Our group does not usually focus on optical properties of materials, but this work was going on at the same time as our art-science collaborations with Diemut, so art influenced science in this case," says Wardle.

Wardle and Cui, who have applied for a patent on the technology, are making the new CNT process freely available to any artist to use for a noncommercial art project.

"Built to take abuse"

Cui measured the amount of light reflected by the material, not just from directly overhead, but also from every other possible angle. The results showed that the material absorbed greater than 99.995 percent of incoming light, from every angle. In essence, if the material contained bumps or ridges, or features of any kind, no matter what angle it was viewed from, these features would be invisible, obscured in a void of black.

The researchers aren't entirely sure of the mechanism contributing to the material's opacity, but they suspect that it may have something to do with the combination of etched aluminum, which is somewhat blackened, with the carbon nanotubes. Scientists believe that forests of carbon nanotubes can trap and convert most incoming light to heat, reflecting very little of it back out as light, thereby giving CNTs a particularly black shade.

"CNT forests of different varieties are known to be extremely black, but there is a lack of mechanistic understanding as to why this material is the blackest. That needs further study," Wardle says.

PHILADELPHIA -- Kidneys from donors who were infected with the Hepatitis C virus (HCV) function just as well as uninfected kidneys throughout the first year following transplantation, according to a new Penn Medicine study. The analysis of kidney transplant recipients across the United States, published today in the Journal of the American Society of Nephrology, also revealed a threefold increase in the number of transplant centers using HCV-infected kidneys and a major change in how the organs are allocated.

Prior to September 2018, the majority of HCV-infected organs were transplanted into patients who already had HCV infection. Since then, however, nearly 75 percent of the patients who were transplanted with HCV-infected kidneys did not already have the virus. Researchers reported similar one-year outcomes for both groups of patients. Despite the increased use of HCV-infected organs and promising outcomes, the Kidney Donor Profile Index (KDPI) Calculator - which combines a variety of donor factors to summarize the likelihood of organ failure after deceased donor transplant - still assigns much worse risk scores to organs from HCV-positive donors.

"These striking results provide additional evidence that the KDPI does not accurately assess the quality of kidneys from HCV-positive donors," said the study's corresponding author Peter Reese, MD, MSCE, an associate professor of Medicine and Epidemiology. "Rescaling the index to reflect these positive outcomes might lead clinicians to offer these kidneys to younger patients with longer life expectancy, when clinically appropriate, and could help expand access for the nearly 100,000 Americans awaiting a kidney transplant."

For decades, most HCV-infected organs in the United States were discarded partly because of concerns that the organs were associated with significantly lower survival rates. However, in recent years, the emergence of new antiviral treatments, coupled with the growing need for kidney transplants, prompted the launch of new studies to test the safety and efficacy of transplanting HCV-infected kidneys into patients on the waitlist who did not have the virus. The studies, including a trailblazing clinical trial launched by Penn Medicine in 2016, revealed that the use of HCV-infected kidneys - when followed by antiviral therapy - can lead to very good transplant outcomes for patients.

However, questions remained about whether the HCV-infected organs would function comparably to similar uninfected kidneys - particularly in patients who did not have the virus - and whether the promising results of the single-center studies would be confirmed in a larger, nationwide study.

A team of researchers, led by Reese and Vishnu Potluri, MD, MPH, an instructor of Nephrology at Penn, analyzed national transplant registry data to examine the use of HCV-infected kidneys between April 2015 and March 2019. To measure how well the kidneys functioned compared to uninfected kidneys, researchers designed highly-similar matched sets, in which the donors had nearly identical qualities - including age, weight and history of high blood pressure - except for HCV status. Researchers then used a widely-used mathematical formula, called the Chronic Kidney Disease Epidemiology Collaboration equation, to estimate each recipient's glomerular filtration rate (eGFR) - a measure that determines how well the blood is filtered by the kidneys. The lower the GFR number, the worse the kidney function. For example, having a GFR below 60 is abnormal. In their analysis, researchers found that recipients who received HCV-infected kidneys had an eGFR of 66.3 at the one-year mark. Patients who received uninfected kidneys had an eGFR of 67.1.

In addition to finding HCV-infected kidneys functioned similarly to uninfected kidneys, the team found transplant centers and patients were increasingly willing to accept the organs. For example, the number of transplant centers using HCV-infected kidneys jumped from 11 in 2015 to 39 centers through the first three months of 2019. Despite the increased acceptance and use of these kidneys, researchers found that nearly 40 percent of the HCV-infected kidneys donated between January 2018 and March 2019 were discarded.

"While the discard rate of these organs has declined in recent years, our findings suggest there is still substantial opportunity to expand the use of HCV-infected organs," said Potluri, the study's lead author. "Our results suggest we should make it a priority to maximize the use of good-quality HCV-infected organs."

AMHERST, Mass. - Scientists expect that in the future, electronically active garments containing unobtrusive, portable devices for monitoring heart rate and respiratory rhythm during sleep, for example, will prove clinically useful in health care. Now researchers at the University of Massachusetts Amherst have developed physiological-sensing textiles that can be woven or stitched into sleep garments they have dubbed "phyjamas."

Graduate students Ali Kiaghadi and S. Zohreh Homayounfar, with their professors Trisha L. Andrew, a materials chemist, and computer scientist Deepak Ganesan, will introduce their health-monitoring sleepwear at the Ubicomp 2019 conference this week in London, U.K. A paper detailing the work has been chosen for publication in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT).

As Andrew explains, "The challenge we faced was how to obtain useful signals without changing the aesthetics or feel of the textile. Generally, people assume that smart textiles refer to tightly worn clothing that has various sensors embedded in it for measuring physiological and physical signals, but this is clearly not a solution for everyday clothing and, in particular, sleepwear."

Ganesan adds, "Our insight was that even though sleepwear is worn loosely, there are several parts of such a textile that are pressed against the body due to our posture and contact with external surfaces. This includes pressure exerted by the torso against a chair or bed, pressure when the arm rests on the side of the body while sleeping, and light pressure from a blanket over the sleepwear."

"Such pressured regions of the textile are potential locations where we can measure ballistic movements caused by heartbeats and breathing," he explains, "and these can be used to extract physiological variables." The difficulty is that these signals can be individually unreliable, particularly in loose-fitting clothing, but signals from many sensors placed across different parts of the body can be intelligently combined to get a more accurate composite reading.

Andrew, Ganesan and colleagues explain that their team had to come up with several new ideas to make their vision a reality. They realized that there is no existing fabric-based method to sense continuous and dynamic changes in pressure, particularly given the small signals that they needed to measure. So they designed a new fabric-based pressure sensor and combined that with a triboelectric sensor - one activated by a change in physical contact - to develop a distributed sensor suite that could be integrated into loose-fitting clothing like pajamas. They also developed data analytics to fuse signals from many points that took into account the quality of the signal coming in from each location.

The authors report that this combination allowed them to detect physiological signals across many different postures. They performed multiple user studies in both controlled and natural settings and showed that they can extract heartbeat peaks with high accuracy, breathing rate with less than one beat per minute error, and perfectly predict sleep posture.

"We expect that these advances can be particularly useful for monitoring elderly patients, many of whom suffer from sleep disorders," says Andrew. "Current generation wearables, like smartwatches, are not ideal for this population since elderly individuals often forget to consistently wear or are resistant to wearing additional devices, while sleepwear is already a normal part of their daily life. More than that, your watch can't tell you which position you sleep in, and whether your sleep posture is affecting your sleep quality; our Phyjama can."

This work was enhanced by Ganesan and Andrew's affiliation with UMass Amherst's Institute of Applied Life Sciences (IALS), which focuses on translating life science research into products that improve human health. Director Peter Reinhart at IALS says, "It's exciting to see the next generation of wearable technology that is zero effort and addresses the issue of comfort and unobtrusiveness head-on. The data generated by fabric-based sensors have the potential to improve health and well-being, and could possibly contribute to the early diagnosis of multiple disorders."

A study involving military veterans with PTSD and cirrhosis of the liver points to an abnormal mix of bacteria in the intestines as a possible driver of poor cognitive performance--and as a potential target for therapy.

The study appeared Aug. 28, 2019, in the American Journal of Physiology.

Lead author Dr. Jasmohan Bajaj says the findings add to the substantial evidence linking gut health and brain function. He says they offer particular hope for people with PTSD and cirrhosis--a common combination in the VA patient population.

"There is room for improvement in terms of the response to current therapies for PTSD," he says. "Targeting the gut microbiota might be an effective way to address the altered gut-brain axis in these patients and improve cognitive function, as well as other parameters of mental and physical health."

Bajaj is a physician-researcher with the McGuire Veterans Affairs Medical Center and Virginia Commonwealth University in Richmond.

Cirrhosis, or scarring of the liver, is prevalent in veterans with PTSD. Common causes include alcohol use disorder, obesity, and hepatitis C. Some patients with cirrhosis develop a complication called hepatic encephalopathy, which affects brain function. They become mentally sluggish and confused, and in severe cases can even lose consciousness.

PTSD, for its part, can also impair cognition. This can occur whether or not patients are taking drugs, such as antidepressants or sedatives, that act on the brain.

The researchers wanted to tease out the impact of abnormal gut microbiota in these conditions, and see whether those with cirrhosis and PTSD had different gut profiles than those with cirrhosis but no PTSD.

Bajaj's team took stool samples from 93 male veterans with cirrhosis, about a third of whom had combat-related PTSD. The other men had been exposed to combat during their military service but had not developed PTSD.

All the veterans completed a battery of cognitive exams. The tests covered areas such as reaction time, spatial ability, memory, and problem-solving.

Compared with the non-PTSD group, the men with PTSD had poorer cognitive performance.

Those with PTSD had microbiota that were less diverse, meaning they had fewer types of bacteria overall. This was true even after the researchers controlled for severity of cirrhosis, prior episodes of hepatic encephalopathy, alcohol use, and psychotropic medication use.

These veterans, along with the relative lack of diversity in their gut, tended to have more potentially harmful types of bacteria, such as Enterococcus and Escherichia/Shigella, and fewer beneficial ones, such as Lachnospiraceae and Ruminococcaceae.

In the study, higher levels of Enterococcus were associated with worse cognitive performance. The Ruminococcaceae family of bacteria, among others, was associated with better performance.

Ruminococcaceae bacteria are prevalent in healthy guts. These beneficial bugs help break down complex carbohydrates, such as those in unprocessed whole grains and legumes. People with healthier diets of this type tend to have higher counts of these organisms.

The same bacteria have been found to be scarcer in people with depression. There has been little study of their role in PTSD.

Could it be that the psychiatric drugs often used to treat PTSD affected these patients' microbiota? The study found that veterans with PTSD had similar gut profiles regardless of what medications they were on for the condition. This suggests the altered gut microbiome is a result of PTSD itself, and not any drug treatment.

One question the study couldn't answer was whether the combat trauma that triggered PTSD also triggered the bacterial changes, or whether those changes resulted over time from the chronic stress of PTSD.

Bajaj says it's hard to tease out that answer without prospectively following service members and veterans over many years, starting from before their deployments, and periodically sampling their gut bacteria. Such a study would be difficult to conduct.

In any case, he believes it's possible that restoring the gut microbiota to a healthy, normal balance could help ease PTSD symptoms--especially when cirrhosis is also in play. But that idea has to be validated in studies.

"We need more research, including basic lab studies and clinical trials, to understand whether therapies that can change the gut microbiota can help these patients, and which particular types of bacteria are most beneficial," says Bajaj. He cited probiotic supplements or fecal transplants as two possible therapy approaches.

Recently, VA's Office of Research and Development launched an initiative to increase the number of such studies. Bajaj was among a group of more than 20 clinicians and biomedical scientists who helped develop a "roadmap" outlining VA's plans to fund work in this area over the next few years.

New research at the University of Saskatchewan (USask) shows how the world's most widely used insecticides could be partly responsible for a dramatic decline in songbird populations.

A study published in the journal Science on Sept. 13 is the first experiment to track the effects of a neonicotinoid pesticide on birds in the wild.

The study found that white-crowned sparrows who consumed small doses of an insecticide called imidacloprid suffered weight loss and delays to their migration--effects that could severely harm the birds' chances of surviving and reproducing.

"We saw these effects using doses well within the range of what a bird could realistically consume in the wild--equivalent to eating just a few treated seeds," said Margaret Eng, a post-doctoral fellow in the USask Toxicology Centre and lead author on the study.

Eng's collaborators on the research were biologist Bridget Stutchbury of York University and Christy Morrissey, an ecotoxicologist in the USask College of Arts and Science and the School of Environment and Sustainability.

Neonicotinoids are the most commonly used class of agricultural insecticides. They are often applied as a seed coating or as a spray on most major crops worldwide.

Although the toxic effects of neonicotinoids were once thought to affect only insects, most notably pollinators such as bees, there is growing evidence that birds are routinely exposed to the pesticides with significant negative consequences.

"Our study shows that this is bigger than the bees--birds can also be harmed by modern neonicotinoid pesticides which should worry us all," said Stutchbury.

Until now, researchers had not been able to assess what happens to pesticide-exposed birds in the wild. The USask and York University scientists used new lightweight tagging technologies and a collaborative research network called the Motus Wildlife Tracking System to track the effects in the sparrows' natural habitat.

The researchers exposed individual sparrows to small doses of the pesticide, imidacloprid, in southern Ontario, Canada during a stopover on the birds' spring migration. Each bird's body composition was measured before and after exposure, and a lightweight radio transmitter was attached to the bird's back to track its movements in the wild.

Birds given the higher dose of the pesticide lost six per cent of their body mass within just six hours. That one dose also caused birds to stay 3.5 days longer, on average, at the stopover site before resuming their migration compared to control birds.

"Both of these results seem to be associated with the appetite suppression effect of imidacloprid. The dosed birds ate less food, and it's likely that they delayed their flight because they needed more time to recover and regain their fuel stores," said Eng.

Because the researchers used controlled dosing, they were able to confirm a cause and effect between neonicotinoid exposures and delayed migration, not just a correlation that is more typical of field studies.

In North America, three-quarters of bird species that rely on agricultural habitat have significantly declined in population since 1966. The results of the new study show a mechanism by which pesticides could be directly contributing to this drop-off.

"Migration is a critical period for birds and timing matters. Any delays can seriously hinder their success in finding mates and nesting, so this may help explain, in part, why migrant and farmland bird species are declining so dramatically worldwide," said Morrissey, senior author on the study.

The three researchers examined the effects of neonicotinoids in a previous study using captive sparrows. The new research reinforces the weight loss effect seen in that 2017 study. Captive birds in the earlier study were also found to become disoriented as a result of neonicotinoid exposure.

"We didn't see that result in wild birds here," said Eng. "In the real-world, birds likely avoid migratory flight while recovering from the effects of the toxin."

Alexander von Humboldt was born 250 years ago this month, and while he spent much of his life studying Earth's mountainous regions, his vision of how science is intertwined with the broader human experience has helped to lay the groundwork for aspects of modern science more broadly. In this special issue of Science, an Editorial, a Perspective, four Reviews and a Policy Forum highlight von Humboldt's lasting legacy on issues related to the ecology and environment of mountains, in particular. These pieces also discuss how his ideas could help humanity better address societal challenges we face in the Anthropocene.

Mountains cover 25% of the Earth's surface but are home to more than 85% of the planet's species of amphibians. As described in a Review by Carsten Rahbek and colleagues, the causes of this species richness remain an open question. Rahbek et al. call this "Humbolt's enigma," and they provide an overview of the research focused on mountain ecosystems worldwide that is attempting to solve this riddle. The authors suggest that the complex interactions between climate and rugged mountain terrain likely played a key role in both generating and maintaining species diversity in the mountains. However, with global climate change and increasing human land use in mountainous environments, their long history as refugia for biodiversity could be threatened. In a second Review, also led by Rahbek, the authors discuss how diverse mountain environments evolved. Their Review highlights how geological and long-term climatic processes shaped global patterns of mountain biodiversity over millions of years.

A third Review by Frank Hagedorn and colleagues discusses the interconnected nature of mountain vegetation and the wildly diverse, yet largely unseen, microbial soil communities in the ground below. While the responses of mountain vegetation to increasing human activity and a changing climate have been well studied, the resulting changes to the soil communities below ground are much less understood. Hagedorn et al. identify how these underground ecosystems might respond to vegetation shifts due to climate change and how this could impact short- and long-term carbon and nutrient cycling, both of which are critical to overall ecosystem function. The authors suggest that the often-overlooked soil biota should be integrated into existing vegetation monitoring programs in order to best assess belowground ecosystem change and its interaction with the changing environments above.

A fourth Review, by Andrea Encalada and colleagues, focuses on tropical montane rivers (TMR) - waterways born in tropical mountains, which often feed into major lowland rivers, floodplains and oceans. They are one of the planet's most understudied ecosystems. Encalada et al. provide a global perspective on TMR and highlight the vast array of ecosystem functions and services they provide to plants, animals and humans worldwide. According to the authors, TMRs are studied under specific contexts but rarely as holistic, dynamic systems that span large elevation and temperature gradients. This unique property allows them to be used as natural model systems to better understand the effects of rapid change, such as those from human or climate impacts, on biodiversity and ecosystem functioning across broader spatial and temporal scales.

In a Perspective, author Stephen Jackson reflects on Humboldt's unique fusion of science with the broader human experience. To Humboldt, nature and humanity are inextricably entwined - a more than 200-year-old observation that has become increasingly clear as our varied impacts on Earth's environments bring reciprocal influences to bear on human welfare. According to Jackson, Humbolt's vision offers a way to address some of the most pressing environmental and social challenges we face in the Anthropocene. "Rekindling Humbolt's vision, and building on his legacy, can provide not only solace and inspiration, but maps and narratives toward a better future for nature and people," Jackson writes.

Finally, a Policy Forum highlights the challenges of mountain communities and how science-informed policy could help in achieving more sustainable and resilient livelihoods for rural mountain dwellers worldwide. Mountain environments are home to nearly 1.1 billion people, many of whom are among the world's poorest individuals. According to Yuka Makino and colleagues, more than half of mountain peoples face food insecurity and a lack of access to services and infrastructure, and their livelihoods - much like the mountain ecosystems they call home - are particularly vulnerable to natural disasters, climate change and unsustainable resource use. As such, identifying ways to protect and conserve mountain ecosystems while enabling mountain communities to improve their livelihoods is a key part in achieving the United Nations' Sustainable Development Goals. Makino and colleagues highlight several partnerships, including the Mountain Partnership, a voluntary alliance of 60 governments, 16 intergovernmental organizations and nearly 300 major groups, working with the U.N. to achieve these goals. The authors demonstrate how scientific research plays a crucial role in developing effective policy towards these efforts.