Tech

Photodiodes are optical sensors that convert the energy of light into electrical energy. Organic photodiodes (OPDs) respond quickly and have the advantage of being able to realize colors free from color filters because they can control the spectral response of wavelengths. However, most of the color controlling methods reported so far do not fit the current trends of small, thin screens because they thicken the photodiodes to cause light distortion. To meet such demands, a POSTECH research team has succeeded in producing thin-film organic photodiodes with an accurate and simple junction engineering.

A research team led by Professor Dae Sung Chung and Ph.D. candidate Mingyun Kang of POSTECH's Department of Chemical Engineering has demonstrated an accurate and convenient junction engineering of organic photodiodes (OPDs) via chemical doping. The research findings were recently published in Materials Horizons, an international journal published by the Royal Society of Chemistry (RSC).

Photodiodes are the result of adding a photo-detection function to the PN junction of a semiconductor, and when light is incident to the diode, it creates an exciton and dissociates into an electron and a hole, which conducts electricity. The current increases as the light becomes stronger.

The research team succeeded in producing thin-film OPDs with color selectivity by controlling only the depletion region width (DW) rather than the overall thickness of the active layer. By doping the organic materials - which has strong electron withdrawing property - to semiconductors, it allows the optical charges to be separated in a precise way.

Organic photodiodes are replacing silicon photodiodes because they are thin and can control the spectral response of wavelength range. However, there has never been a case where the wavelength range was adjusted while maintaining the thinness of photodiodes. This study is the first case that confirmed that photodiodes' spectral response of wavelength can be freely refined, significant for producing thin-film color-filter-free optical sensors.

"By developing photodiodes that only respond to certain wavelengths using chemical doping, we have produced optical sensors that fundamentally inhibit signal generation due to unwanted wavelengths," elaborated Professor Dae Sung Chung who led the study. He added, "Unlike the existing strategies of detecting light in narrowband, we can freely control the wavelength of light."

Bronze Age pastoralists in what is now southern Russia apparently covered shorter distances than previously thought. It is believed that the Indo-European languages may have originated from this region, and these findings raise new questions about how technical and agricultural innovations spread to Europe. An international research team, with the participation of the University of Basel, has published a paper on this topic.

During the Bronze Age (ca. 3900 - 1000 BCE), herders and their families moved across the slopes of the Caucasus and the steppes to the north, taking their sheep, goats and cattle with them. It is believed that the Indo-Germanic groups, who brought the Indo-European languages and technical innovations such as wagons, domestic horses and metal weapons to Europe, may have originated from this region.

Until now, experts assumed that this transfer of technology was based on the long-distance migrations and trade contacts of these mobile pastoral communities, and that this mobility connected the Middle East with Europe. An international research team, with the participation of the University of Basel, has now questioned whether these communities did actually travel over such long distances. They published their study in the journal Plos One.

Nutrition reveals low levels of mobility

The researchers reconstructed the diet of the Bronze Age pastoral societies in order to draw conclusions about their migration. Their analysis was based on skeletal remains from burial mounds and flat grave cemeteries on the plateaus of the Caucasus and the steppes bordering to the north. "These human bones and teeth are archaeological treasures," says the study's author Professor Kurt Alt, visiting professor at the University of Basel and professor at Danube Private University in Krems. "They are fundamental resources for gaining a deeper understanding of economic strategies, the mobility patterns associated with them and social differentiation."

The research team analyzed the isotopic composition of carbon and nitrogen in bone collagen from the skeletal remains of 150 people, taken from eight sites. The finds date back to a period from about 5000 to about 500 BCE. In addition, the scientists compared this data with the isotope ratios in the bone collagen of 50 animals, as well as with the local vegetation of that time. The isotope ratios in bone collagen reflect the isotope ratios in the main foodstuffs that a person eats.

As it turns out, the diets of these groups were mainly based on the foodstuffs within the landscapes where their remains were found. "The communities apparently remained within their respective ecological areas and did not switch between the steppes, forest steppes or higher regions," explains Sandra Pichler from the Department of Environmental Sciences at the University of Basel, co-author of the study. According to the isotope analysis, meat, milk and dairy products formed a large part of these individuals' basic diets, but they were supplemented by wild plants, too. It was not until the end of the Bronze Age that their diets began to be based more on cultivated cereals, with millet presumably the main crop in this regard.

Technology transfer by word of mouth

"This study's findings imply that Caucasian communities were not highly mobile and did not undertake large-scale migrations, suggesting that the revolutionary technical innovations of the 4th and 3rd millennium BCE, such as wagons or metal weapons, were transmitted in other ways."

If the pastoral communities of the time only moved across shorter distances, technologies could have been passed on from one group to the next transmitting the knowledge of metal weapons, the processing of bronze and the domestication of horses into Europe by word of mouth.

As part of its foreign policy, Germany hopes to promote energy transitions abroad through international energy partnerships. A new study by the Institute for Advanced Sustainability Studies (IASS) analyses these bilateral energy partnerships. Building on its reputation as an energy transition frontrunner, Germany is currently pursuing a soft power strategy aimed at winning over foreign countries to its policy approaches in the energy sector. According to this analysis, Germany's bilateral energy partnerships are the central policy instrument to this end.

International agreements on climate protection require a rapid reduction in energy-related greenhouse gas emissions. How energy is produced and consumed must change if this is to be achieved. Governments can promote new energy technologies through targeted investments. Government support for renewable energy has seen costs fall sharply over the past two decades, making electricity from wind and solar installations competitive with coal and nuclear-generated energy.

This development has also resulted in a shift in foreign energy policy in which traditional approaches to securing fossil-based energy resources have been augmented by efforts to foster the uptake of climate-friendly technologies and solutions. As an international pioneer of renewable energies and an important industrialized country, Germany has emerged as a key player in this new field of foreign energy policy. In a recent article in the journal Review for International Political Economy, IASS researchers Rainer Quitzow and Sonja Thielges discuss the German government's international energy transition policy. The authors describe the so-called Energiewende as the central foundation or "soft power" resource of this strategy and show how the growing domestic consensus on the German energy transition's reflected in the country's foreign energy policy.

A German energy transition narrative emerges

The energy transition in Germany unfolded over a period of more than thirty years. Rooted in the experiences of the oil crisis in the 1970s and the anti-nuclear movement, a cross-party consensus in favour of renewable energy generation emerged by 2010. In the wake of the Fukushima Daiichi nuclear disaster, the German government made the decision to phase out nuclear power and place the Energiewende concept at the centre of German energy policy.

Domestic policy goes global

"This domestic political development is also reflected in Germany's international political agenda and narrative," explains Rainer Quitzow, author of the study and speaker of the IASS Research Area on Energy Systems and Societal Change. In 2002, Germany used the World Summit on Sustainable Development in Johannesburg, South Africa as a platform to vigorously advocate for renewable energies. In the same year, Germany supplemented its efforts in the field of development cooperation with the export promotion programme "Renewables - Made in Germany".

The first energy partnerships, focused on renewable energies and energy efficiency, were launched with India and China in 2006. Similar partnerships were established in the following years with Brazil, Morocco, Tunisia and South Africa, among others. In addition to these partnerships led by the Federal Ministry for Economic Affairs and Energy (BMWi), the Federal Foreign Office (AA) also maintains various partnerships, such as the German-Nigerian Energy Partnership. "Today, these partnerships lie at the heart of Germany's 'soft power' strategy," says author Sonja Thielges, senior research associate at the IASS Research Group on Pathways to Sustainable Energy. The role and function of energy partnerships within Germany's international energy transition policy are analysed in detail in the article and in an IASS Discussion Paper.

The energy transition as an international 'soft power' strategy of the German government

Sustainable energy, the environment and climate have played an important role in German diplomacy for more than a decade now. The Federal Foreign Office, for example, appointed a special representative for climate and energy policy. Over time, the energy transition emerged as the German government's central narrative for these policy areas. Surveys in 2012, 2015 and 2017 examined international perceptions of the German energy transition. The findings revealed that this policy was viewed with admiration and interest outside of Europe. This was particularly evident in countries with considerable potential for renewable energy generation, such as Morocco, where perceptions of the German energy transition are overwhelmingly positive.

Positive perceptions of the energy transition serve as a basis - or "soft power resource" as the authors note - for high-level political dialogue within the framework of the energy partnerships. Key features of this soft power strategy is the combination of communication and political dialogue on the one hand and capacity-building and learning on the other.

"The latter bolsters the credibility of political communication and increases the partners' ability to pursue an energy policy based on the German model, which promotes renewables and energy efficiency", says Rainer Quitzow. In addition, the institutional character and duration of partnerships builds trust, which helps to strengthen other activities. In the case of South Africa, for example, the energy partnership has raised awareness of issues relating to energy transitions among state actors, according to the authors. At the same time, the political dialogue provides a forum for identifying topics that could be addressed in workshops and study visits.

The energy partnerships also have the potential to provide a framework for the inter-ministerial coordination of international energy transition policy within partner countries, write the authors. However, operating under the umbrella of the BMWi and/or AA, the partnerships are not mandated to assume this function. As a result, the federal ministries frequently pursue parallel activities relevant to the energy sector without active coordination.

AMES, Iowa - New research shows a simple skin test can accurately identify Parkinson's disease, demonstrating for the first time the feasibility of the method. Currently diagnosed by clinical signs and symptoms but only definitively diagnosed at autopsy, Parkinson's disease is commonly misdiagnosed early in the disease course, complicating clinical trials of potential treatments.

The study, published in the scientific journal Movement Disorders, shows how a chemical assay can detect clumping of the protein alpha-synuclein in skin samples to help diagnose Parkinson's disease (PD). The study's authors said using the assay can lead to earlier detection of PD and better clinical trials.

"Since there's no easy and reliable test available for the early diagnosis of Parkinson's disease at present, we think there will be a lot interest in the potential use of skin samples for diagnosis," said Anumantha Kanthasamy, Distinguished Professor of Biomedical Sciences at Iowa State and lead author of the study.

The researchers conducted a blinded study of 50 skin samples provided by the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND)/Brain and Body Donation Program based at Banner Sun Health Research Institute. Half of the skin samples came from patients with Parkinson's disease and half came from people without neurologic disease. Using the protein assay correctly diagnosed 24/25 Parkinson's disease patients and only 1/25 controls had the protein clumping. Dr. Charles Adler, M.D., professor of neurology at Mayo Clinic Arizona, a co-investigator of the study, notes that "these results indicate tremendously high sensitivity and specificity which is critical for a diagnostic test."

"The clinical diagnostic accuracy for early-stage PD has been quite poor, only around 50-70%. And since clinical trials really need to be done at an early stage to avoid further brain damage, they have been critically hampered because they have been including large percentages of people who may not actually have the disease," said Dr. Thomas Beach, MD, a co-investigator of the study and head of the Civin Laboratory at Banner Sun Health Research Institute. "Improving clinical diagnostic accuracy is, in my view, the very first thing we need to do in order to find new useful treatments for PD."

The research centers on a method known as the real-time quaking induced conversion assay, a test that was originally developed to detect mad cow disease. Kanthasamy's laboratory has spent several years optimizing the assay for detecting misfolded proteins in similar human and animal disorders. Parkinson's disease arises from misfolded alpha-synuclein proteins that accumulate in the brain leading to neuronal damage. Adler and Beach have led research in AZSAND that has found these misfolded alpha-synuclein proteins also collect in other body tissues as well, including the skin.

Kanthasamy said testing skin samples could lead to earlier detection of Parkinson's disease. Earlier diagnosis could allow physicians to test therapeutic strategies designed to slow or prevent the development of advanced symptoms, he said.

There are places that will always be beyond our reach. The Earth's interior is one of them. But we do have ways of gaining an understanding of this uncharted world. Seismic waves, for instance, allow us to put important constraints about the structure of our planet and the physical properties of the materials hidden deep within it. Then there are the volcanic rocks that emerge in some places on the Earth's surface from deep within and provide important clues about the chemical composition of the mantle. And finally there are lab experiments that can simulate the conditions of the Earth's interior on a small scale.

A new publication by Motohiko Murakami, Professor of Experimental Mineral Physics, and his team was featured recently in the journal PNAS and shows just how illuminating such experiments can be. The researchers' findings suggest that many geoscientists' understanding of the Earth's interior may be too simplistic.

Dramatic change

Below the Earth's crust, which is only a few kilometres thick, lies its mantle. Also made of rock, this surrounds the planet's core, which begins some 2,900 kilometres below us. Thanks to seismic signals, we know that a dramatic change occurs in the mantle at a depth of around 660 kilometres: this is where the upper mantle meets the lower mantle and the mechanical properties of the rock begin to differ, which is why the propagation velocity of seismic waves changes dramatically at this border.

What is unclear is whether this is merely a physical border or whether the chemical composition of the rock also changes at this point. Many geoscientists presume that the Earth's mantle as a whole is composed relatively consistently of magnesium-rich rock, which in turn has a composition similar to that of peridotite rock found on the Earth's surface. These envoys from the upper mantle, which arrive on the Earth's surface by way of events like volcanic eruptions, exhibit a magnesium-silicon ratio of ~1.3.

"The presumption that the composition of the Earth's mantle is more or less homogeneous is based on a relatively simple hypothesis," Murakami explains. "Namely that the powerful convection currents within the mantle, which also drive the motion of the tectonic plates on the Earth's surface, are constantly mixing it through. But it's possible that this view is too simplistic."

Where's the silicon

There really is a fundamental flaw in this hypothesis. It is generally agreed that the Earth was formed around 4.5 billion years ago through the accretion of meteorites that emerged from the primordial solar nebula, and as such has the same overall composition of those meteorites. The differentiation of the Earth into core, mantle and crust happened as part of a second step.

Leaving aside the iron and nickel, which are now part of the planet's core, it becomes apparent that the mantle should actually contain more silicon than the peridotite rock. Based on these calculations, the mantle should have a magnesium-silicon ratio closer to ~1 rather than ~1.3.

This moves geoscientists to ask the following question: where is the missing silicon And there is an obvious answer: the Earth's mantle contains so little silicon because it is in the Earth's core. But Murakami reaches a different conclusion, namely that the silicon is in the lower mantle. This would mean that the composition of the lower mantle differs to that of the upper mantel.

Winding hypothesis

Murakami's hypothesis takes a few twists and turns: First, we already know precisely how fast seismic waves travel through the mantle. Second, lab experiments show that the lower mantle is made mostly of the siliceous mineral bridgmanite and the magnesium-rich mineral ferropericlase. Third, we know that the speed the seismic waves travel depends on the elasticity of the minerals that make up the rock. So if the elastic properties of the two minerals are known, it is possible to calculate the proportions of each mineral required to correlate with the observed speed of the seismic waves. It is then possible to derive what the chemical composition of the lower mantle must be.

While the elastic properties of ferropericlase are known, those of bridgmanite are as yet not. This is because this mineral's elasticity depends greatly on its chemical composition; more specifically, it varies according to how much iron the bridgmanite contains.

Time-consuming measurements

In his lab, Murakami and his team have now conducted high-pressure tests on this mineral and experimented with different compositions. The researchers began by clamping a small specimen between two diamond tips and using a special device to press them together. This subjected the specimen to extremely high pressure, similar to that found in the lower mantle.

The researchers then directed a laser beam at the specimen and measured the wave spectrum of the light dispersed on the other side. Using the displacements in the wave spectrum, they were able to determine the mineral's elasticity at different pressures. "It took a very long time to complete the measurements," Murakami reports. "Since the more iron bridgmanite contains the less permeable to light it becomes, we needed up to fifteen days to complete each individual measurement."

Silicon discovered

Murakami then used the measurement values to model the composition that best correlates with the dispersal of seismic waves. The results confirm his theory that the composition of the lower mantle differs to that of the upper mantel. "We estimate that bridgmanite makes up 88 to 93 percent of the lower mantle," Murakami says, "which gives this region a magnesium-silicon ratio of approximately 1.1." Murakami's hypothesis solves the mystery of the missing silicon.

But his findings raise new questions. We know for instance that within certain subduction zones, the Earth's crust gets pushed deep into the mantle - sometimes even as far as the border to the core. This means that the upper and lower mantles are actually not hermetically separated entities. How the two areas interact and exactly how the dynamics of the Earth's interior work to produce chemically different regions of mantle remains to be seen.

Researchers at Tokyo Institute of Technology (Tokyo Tech) and Carnegie Mellon University have together developed a new human motion capture system that consists of a single ultra-wide fisheye camera mounted on the user's chest. The simplicity of their system could be conducive to a wide range of applications in the sports, medical and entertainment fields.

Computer vision-based technologies are advancing rapidly owing to recent developments in integrating deep learning. In particular, human motion capture is a highly active research area driving advances for example in robotics, computer generated animation and sports science.

Conventional motion capture systems in specially equipped studios typically rely on having several synchronized cameras attached to the ceiling and walls that capture movements by a person wearing a body suit fitted with numerous sensors. Such systems are often very expensive and limited in terms of the space and environment in which the wearer can move.

Now, a team of researchers led by Hideki Koike at Tokyo Tech present a new motion capture system that consists of a single ultra-wide fisheye camera mounted on the user's chest. Their design not only overcomes the space constraints of existing systems but is also cost-effective.

Named MonoEye, the system can capture the user's body motion as well as the user's perspective, or 'viewport'. "Our ultra-wide fisheye lens has a 280-degree field-of-view and it can capture the user's limbs, face, and the surrounding environment," the researchers say.

To achieve robust multimodal motion capture, the system has been designed with three deep neural networks capable of estimating 3D body pose, head pose and camera pose in real-time.

Already, the researchers have trained these neural networks with an extensive synthetic dataset consisting of 680,000 renderings of people with a range of body shapes, clothing, actions, background and lighting conditions, as well as 16,000 frames of photo-realistic images.

Some challenges remain, however, due to the inevitable domain gap between synthetic and real-world datasets. The researchers plan to keep expanding their dataset with more photo-realistic images to help minimize this gap and improve accuracy.

The researchers envision that the chest-mounted camera could go on to be transformed into an everyday accessory such as a tie clip, brooch or sports gear in future.

Researchers at Tokyo Institute of Technology (Tokyo Tech) working in collaboration with colleagues at Carnegie Mellon University, the University of St Andrews and the University of New South Wales have developed a wrist-worn device for 3D hand pose estimation. The system consists of a camera that captures images of the back of the hand, and is supported by a neural network called DorsalNet which can accurately recognize dynamic gestures.

Being able to track hand gestures is of crucial importance in advancing augmented reality (AR) and virtual reality (VR) devices that are already beginning to be much in demand in the medical, sports and entertainment sectors. To date, these devices have involved using bulky data gloves which tend to hinder natural movement or controllers with a limited range of sensing.

Now, a research team led by Hideki Koike at Tokyo Tech has devised a camera-based wrist-worn 3D hand pose recognition system which could in future be on par with a smartwatch. Their system can importantly allow capture of hand motions in mobile settings.

"This work is the first vision-based real-time 3D hand pose estimator using visual features from the dorsal hand region," the researchers say. The system consists of a camera supported by a neural network named DorsalNet which can accurately estimate 3D hand poses by detecting changes in the back of the hand.

The researchers confirmed that their system outperforms previous work with an average of 20% higher accuracy in recognizing dynamic gestures, and achieves a 75% accuracy of detecting eleven different grasp types.

The work could advance the development of controllers that support bare-hand interaction. In preliminary tests, the researchers demonstrated that it would be possible to use their system for smart devices control, for example, changing the time on a smartwatch simply by changing finger angle. They also showed it would be possible to use the system as a virtual mouse or keyboard, for example by rotating the wrist to control the position of the pointer and using a simple 8-key keyboard for typing input.

They point out that further improvements to the system such as using a camera with a higher frame rate to capture fast wrist movement and being able to deal with more diverse lighting conditions will be needed for real world use.

Preeclampsia, a pregnancy complication characterized by high blood pressure, occurs in about 7 percent of pregnancies and is a leading cause of maternal mortality and premature birth. The condition can appear in a variety of forms both early and late in pregnancy, making it difficult to test and therefore hard to prevent or treat. To improve early detection of preeclampsia risks and better classify potential subtypes of the disease, a team led by researchers from Brigham and Women's Hospital analyzed an array of maternal and placental proteins, identifying several biomarkers that, from a blood sample drawn at 12 weeks gestation, can help predict the risk of preeclampsia and, equally importantly, can assess who may develop more severe forms of the condition. Findings are published in Scientific Reports.

"For many, many years, preeclampsia was assumed to be one disease," said corresponding author Thomas McElrath, MD, PhD, of the Division of Maternal-Fetal Medicine in the Department of Obstetrics and Gynecology at the Brigham. "This study is starting to show that there are potentially multiple different forms of preeclampsia that come together in one common clinical presentation, and once we understand what the subgroups are, we may be more effective at testing or treating them."

The researchers were the first to study the relationship between preeclampsia and proteins associated with circulating microparticles (CMPs), which are virus-sized cellular secretions that contain small proteins and RNA, among other cellular products. In humans and ancient life forms alike, the transmission of CMPs facilitates communication between cells by modifying the receiving cells' functions. The researchers found that at 10-12 weeks of pregnancy, women who would later develop preeclampsia already had different CMP-associated proteins than women who ultimately had healthy pregnancies. They identified four proteins, in particular, that seemed to be indicative of preeclampsia risk.

"If we can eavesdrop on the conversations that cells are having with each other about what they're trying to modify in the patient, then we might have the ability to predict what the future holds for that patient and what her risks are," McElrath said.

Furthermore, when the researchers examined how CMP proteins differed across the patients who got preeclampsia, they found that more severe forms, with higher blood pressure and worse lab testing, were associated with proteins indicative of the complement system -- a branch of the immune system -- dysfunction. They identified another possible subgroup of preeclampsia linked to platelet dysfunction.

"To develop therapies, we need better information about what pathophysiologic pathways to target," McElrath said. "The idea that we might be able to identify women most at risk early on in pregnancy means that we might be able to develop more efficient testing and therapies."

This study utilized data from the Brigham's LIFECODES Cohort, which includes records of approximately 6,000 pregnancies and is one of the nation's largest pregnancy cohorts and specimen banks. The team analyzed CMP-associated proteins in 23 women diagnosed with severe forms of preeclampsia at or before 34 weeks of gestation, most of whom delivered before 35 weeks, and in 50 women who delivered after at least 37 weeks of gestation without evidence of any hypertensive diseases, including preeclampsia.

By comparing the most severe cases of preeclampsia to the healthiest pregnancies, the researchers were able to complete a preliminary, proof-of-principle investigation, but acknowledged that their small, specific sample makes it harder to generalize the patterns they've observed in CMP-associated proteins to the entire population.

Going forward, the researchers hope to validate their results by analyzing thousands of pregnancies, aggregating data from the LIFECODES Cohort and other birth cohorts nationwide. They hope to study proteins in women with later-stage preeclampsia, and in doing so, identify other subgroups of preeclampsia.

"We really don't have a prognostic test for preeclampsia," McElrath said. "Ideally, this will help develop a test that could be used at the woman's first prenatal visit to help us decide if she's at higher or lower risk of preeclampsia and put her in a plan of care in accordance with that risk."

Certain species of snake - think pit vipers, boa constrictors and pythons, among others - are able to find and capture prey with uncanny accuracy, even in total darkness. Now scientists have discovered how these creatures are able to convert the heat from organisms that are warmer than their ambient surroundings into electrical signals, allowing them to "see" in the dark.

The work, published in the journal >Matter, provides a new explanation for how that process works, building upon the researchers' previous work to induce pyroelectric qualities in soft materials, allowing them to generate an electric charge in response to mechanical stress.

Researchers have known electrical activity was likely to be involved in allowing the snakes to detect prey with such exceptional skill, said Pradeep Sharma, M.D. Anderson Chair Professor of mechanical engineering at the University of Houston and corresponding author for the paper. But naturally occurring pyroelectric materials are rare, and they are usually hard and brittle. The cells in the pit organ - a hollow chamber enclosed by a thin membrane, known to play a key role in allowing snakes to detect even small temperature variations - aren't pyroelectric materials, said Sharma, who also is chairman of the Department of Mechanical Engineering at UH.

But when he and colleagues last year reported producing pyroelectric effects in a soft, rubbery material, something clicked.

"We realized that there is a mystery going on in the snake world," he said. "Some snakes can see in total darkness. It would be easily explained if the snakes had a pyroelectric material in their bodies, but they do not. We realized that the principle behind the soft material we had modeled probably explains it."

Not all snakes have the ability to produce a thermal image in the dark. But those with a pit organ are able to use it as an antenna of sorts to detect the infrared radiation emanating from organisms or objects that are warmer than the surrounding atmosphere. They then process the infrared radiation to form a thermal image, although the mechanism by which that happened hasn't been clear.

Sharma and his colleagues determined that the cells inside the pit organ membrane have the ability to function as a pyroelectric material, drawing upon the electrical voltage that is found in most cells. Through modeling, they used their proposed mechanism to explain previous experimental findings related to the process.

"The fact that these cells can act like a pyroelectric material, that's the missing connection to explain their vision," Sharma said.

This work was part of the Ph.D. dissertation of Faezeh Darbaniyan, first author on the paper. Additional researchers on the project include Kosar Mozaffari, a student at UH, and Professor Liping Liu of Rutgers University.

The work explains the mechanism by which the cells are able to take on pyroelectric properties, although questions remain, including how the proposed mechanism is related to the role played by the increased number of ion channels found in TRPA1 proteins. TRPA1 proteins are more abundant in the cells of pit-organ snakes than in non-pit snakes.

"Our mechanism is very robust and simple. It explains quite a lot," Sharma said. "At the same time, it is undeniable these channels play a role as well, and we are not yet sure of the connection."

Despite the remarkable successes of immune-based treatments for cancer, not everyone responds to these approaches and relapses do occur. Researchers around the world are racing to find ways to improve outcomes for people receiving immunotherapy. But new findings from scientists at Memorial Sloan Kettering suggest they may be focusing too narrowly on the problem.

According to Ming Li, an immunologist in the Sloan Kettering Institute, most existing immunotherapy approaches, including both checkpoint blockade and CAR T therapy, aim to prod the immune system into finding and killing cancer cells -- a kind of frontal attack on the disease.

But tumors also need supportive environments -- safe harbors -- in which to grow and thrive. "They need the support of blood vessels that provide them with nutrients," Dr. Li says.

Could destroying these safe harbors be an indirect way to fight this internal enemy? Dr. Li thinks the answer is yes, and on October 21 he published two papers in the journal Nature in support of the concept.

"We know that the immune system is incredibly adept at recognizing harmful invaders and attacking them with precision," he says. "But that's not the only way our immune system protects us from threats. It also promotes healing of damaged tissue so that pathogens can't take root in the body. This latter role, we now show, can also be enlisted in the fight against cancer."

Dr. Li and his colleagues found they could thwart cancers in mice by encouraging immune cells to begin the process of wound repair around a tumor. In the process, blood vessels that feed the cancer are pruned away and cancer cells starve and die. It's an approach that Dr. Li has dubbed "cancer environment immunotherapy."

Wounds and Cancer

To understand how wound healing can help curb cancer, consider what happens when someone gets an injury, say a cut from a knife. Early on, the site becomes inflamed -- red, hot, and swollen. During this phase of wound healing, blood vessels dilate and immune cells rush in to fight enemies that may cause infection and clean up the debris. But later on, the wound fills in with new tissue, and inflammation resolves.

An important player in the wound healing process is a molecule called TGF-beta, whose presence waxes and wanes with the inflammation cycle. In the context of a cancerous "wound," TGF-beta persists and makes cancer growth worse. By contrast, blocking its action inhibits tumor development. This latter effect is dependent upon immune cells called T cells, previous research has shown.

Dr. Li and his team wanted to find out more about which T cells were involved in curbing cancer growth when TGF-beta is blocked. They initially suspected that a subset of T cells called CD8 T cells, or "killer" T cells, were responsible for restraining tumor development. But when they genetically removed the receptor for TGF-beta from CD8 cells in mice, it had no effect on cancer growth.

Next, they asked whether a different subset of T cells, called CD4 T cells, or "helper" T cells, could explain the phenomenon of cancer suppression. Indeed, genetically removing the receptor for TGF-beta in CD4 T cells dramatically reduced cancer growth in mice.

How do CD4 T cells contribute to cancer control in this context? Dr. Li and his colleagues found that these cells promote wound healing around a tumor. As part of this process, the blood vessels supplying nutrients to a tumor are dramatically remodeled, and a kind of protective wall is formed around the tumor, depriving it of sustenance.

These results, reported in the first Nature paper, showed that blocking TGF-beta signaling in CD4 T cells could activate a powerful wound healing response that directly opposes cancer development.

But what about tumors that have already been growing? Could blocking TGF-beta restrain them? Dr. Li and his team explored this question in a second set of experiments, published in a second Nature article.

They designed an antibody-based drug that can bind to both TGF-beta and T helper cells. They found that this drug, which they called 4T-Trap, could dramatically reduce cancer in mice.

Previous attempts at blocking TGF-beta as a cancer treatment have not been successful, likely because this molecule has many effects in the body and therefore blocking it completely can cause severe side effects such as heart problems or even the appearance of new cancers. But 4T-Trap targets the TGF-beta-blocking-molecule directly to CD4 T cells, so side effects are reduced. In other words, it's a more targeted approach.

"An Exciting Homecoming"

That fact that CD4 T helper cells were the key players rather than CD8 killer T cells came as something of a surprise to the researchers. "These days, CD8 cytotoxic T cells that recognize cancer cells are in the spotlight." Dr. Li says, "It's almost become dogma that if it's T cell mediated, then it must be CD8 T cells. That was our original hypothesis, too. But that turns out not to be the case."

Yet the findings are not completely unprecedented. In fact, the discovery that the promotion of wound healing can dramatically curb cancer progression meshes nicely with older work. In the mid-1980s, cancer researcher Harold Dvorak published a now-famous article in the New England Journal of Medicine, in which he argued that tumors are essentially "wounds that do not heal." Tumors enlist normal wound healing to help themselves grow. They thrive by enlisting the early stages of the immune responses to tissue damage -- growth of new blood vessels, for example -- but then never get to later stages of wound healing when these blood vessels are normally pruned away.

"By blocking TGF-beta in T helper cells, we allow the wound healing to run to completion," Dr. Li says. "We heal the wound that is cancer."

Reflecting on the way his results echo these earlier findings, Dr. Li says, "it's an exciting homecoming."

He proposes that such "cancer environment immunotherapy" could be a powerful addition to current immune-based treatments for cancer. His lab is currently collaborating with physician-researchers at MSK to translate these new findings to patients.

What impact does a classroom's indoor environment have on teaching, learning, and students' academic achievement in colleges and universities? This is the question researchers set out to answer in their analysis of all relevant published studies.

In the analysis published in Indoor Air, the team looked at indoor air, thermal, acoustic, and lighting conditions. The collected evidence from 21 studies showed that the indoor environmental quality can contribute to the quality of learning. Sufficient evidence confirmed that poor indoor air, thermal, acoustic, and lighting conditions negatively influence the quality of learning due to discomfort and impaired mental and physical health of students. On the other hand, optimal conditions can create an environment in which students feel more alert and pay more attention.

Study results also indicated that indoor environmental quality can affect short-term students' academic performance, with a preference for a relatively cool, bright, and quiet environment and in ambient air with low carbon dioxide concentrations.

The influence of all parameters on the quality of teaching and on students' long-term academic performance could not be determined, however.

"Several studies showed that there is not a single optimal indoor environmental condition for students in higher education classrooms. Conditions in which students perform at their best are task-dependent. Therefore, classrooms should provide multiple indoor environmental conditions, in order to facilitate educational processes optimally," said lead author Henk W. Brink, MSc, of the Hanze University of Applied Sciences, in the Netherlands.

School bullying has been identified as harmful to students' mental health. Many studies have evaluated the effectiveness of bullying prevention programs, finding mixed results in general and no benefits overall for secondary school students. Looking at the specific components of bullying prevention programs helps to explain the complicated pattern: Unlike intensive programs that include parent training, firm disciplinary methods or improved playground supervision, interventions that involve work with peers tend to lead to increases in bullying. A new review explores why encouraging peers to defend victims may actually cause more harm than good.

The analysis was written by a researcher at the QIMR Berghofer Medical Research Institute and the University of Queensland, Brisbane. It appears in Child Development Perspectives, a journal of the Society for Research in Child Development.

"Many school bullying prevention programs encourage and train peer bystanders (helpers) to get actively involved in assisting with possible instances of bullying," said Karyn L. Healy, research officer from QIMR Berghofer Medical Research Institute, who authored the analysis. "Although this approach is very common and well-intentioned, there is no evidence that it helps victims. Encouraging peers to actively defend victims of bullying may actually produce adverse outcomes for victims."

Most research on the effectiveness of bullying prevention programs assumes that each program affects bullying and victimization in a simple and unified way. But many programs combine a range of different strategies and participants, which are likely to produce differential effects.

Healy identified several mechanisms through which bystander interventions that involve peer defense of the victim could increase victimization and distress of victims: 1) by disempowering victims, 2) by reinforcing or provoking bullying, or 3) by eroding broader support for victims by the peer group.

"Having lots of peers involved makes the situation more public, which can be damaging to the social reputation of victims," said Healy. "Having a trained bystander step in also prevents the victim from handling a situation themselves and may make them look weak in the eyes of the bully. Training students to intervene in bullying also has the potential of leading to overuse of peer defense strategies because of benefits to helpers, such as making helpers feel they have higher status or increasing helpers' feelings of belonging in school."

Recent evidence suggests that even when programs are successful in reducing bullying, they may still be harmful to the individual students who are victimized the most. "This could potentially be the case for any program that aims to reduce overall bullying without taking into account the impacts on victims," explains Healy.

To lessen the risk to vulnerable students, Healy suggests that schools be wary of bullying prevention programs that lack evidence of effectiveness for reducing bullying and victimization. Schools should avoid using strategies that boost peer visibility of victimization (e.g., identifying a victim in a class meeting). In addition, evaluations of bullying prevention programs that look at the school as a whole should be cautious of hidden negative outcomes for individual students who remain victimized.

Oncotarget Volume 11, Issue 30 reported that genomic profiling of murine mammary tumor cells with differential VDR expression identified 35 transcripts that were altered by the 1,25D3-VDR complex including Hyaluronan Synthase-2.

Here the Oncotarget authors confirmed that 1,25D3 reduces both HAS2 gene expression and hyaluronic acid synthesis in multiple models of breast cancer.

HAS2 expression and HA production are elevated in immortalized human mammary epithelial cells induced to undergo epithelial-mesenchymal transition through stable expression of TGFβ, SNAIL or TWIST and in those expressing oncogenic H-RASV12, indicating that deregulation of HA production may be an early and frequent event in breast tumorigenesis.

1,25D3 also reduces HA secretion and acts additively with an HA synthesis inhibitor to slow growth of cells expressing TGFβ, SNAIL and TWIST. Analysis of mammary gland and tumors from Vdr knockout mice suggest that loss of VDR is associated with enhanced HAS2 expression and HA production in vivo.

These data define a novel role for 1,25D3 and the VDR in control of HA synthesis in epithelial tissues that likely contributes to its anti-cancer actions.

Dr. JoEllen Welsh from The University at Albany said "1,25-Dihydroxyvitamin D3 (1,25D3), the high affinity ligand for the nuclear VDR, regulates multiple cancer processes (cell cycle, apoptosis, migration, invasion) in vivo and in vitro, however the specific gene targets and mechanisms that mediate these effects are unclear."

These authors previously established invasive mammary tumor cell lines from wild-type and VDR knockout mice and demonstrated that the VDR is necessary for 1,25D3 mediated anti-cancer signaling in vitro and in vivo.

One of the VDR down-regulated genes was Has2, an enzyme that synthesizes the polysaccharide hyaluronic acid.

1,25D3 treatment reduced Has2 expression 50–70% in VDR positive cells but was without effect in VDR negative cells.

Collectively, these data suggest that survival and outgrowth of CD44 cancer stem cells are dependent on continued HA synthesis through HAS2 activity.

This concept predicts that disruption of HA-CD44 signaling would inhibit disease progression in patients whose tumors overexpress HAS2. In the studies reported here the authors assessed whether 1,25D3 regulates HAS2 in cellular models of human breast cancer, and whether suppression of HAS2 by 1,25D3 is sufficient to inhibit HA synthesis in the context of aggressive disease.

The Welsh Research Team concluded in their Oncotarget Research Paper that although VDR may frequently be retained in breast tumors, many women with breast cancer are vitamin D deficient.

Therefore, attention to vitamin D status and/or vitamin D supplementation may be necessary to ensure appropriate VDR transcriptional activity in tumors.

In support of a beneficial effect of vitamin D in cancer, the most recent meta-analysis of vitamin D trials including VITAL indicated a significant reduction in cancer mortality with vitamin D supplementation.

The data suggest that the anti-tumor actions of vitamin D may be mediated in part through suppression of HA signaling. In the METABRIC dataset, HAS2 was overexpressed in 27% of all breast tumors, with highest frequency in those subtypes with poor prognosis.

Since HA content is increased during breast cancer progression and elevations in HAS2 and HA correlate with poor prognosis, further studies to evaluate the association of vitamin D signaling and the HA pathway in aggressive human breast cancers are of significant interest.

The data suggest that combining vitamin D supplementation with therapies that target HA signaling or the hexosamine pathway may be therapeutically beneficial.

Oncotarget Volume 11, Issue 30 reported that recent evidence shows that the host innate immunity is also critical in sensing the presence of cytoplasmic DNA derived from genomic instability events, such as DNA damage and defective cell cycle progression.

This is achieved through the cyclic GMP-AMP synthase /Stimulator of interferon genes pathway.

Here the Oncotarget authors discuss recent insights into the regulation of this pathway in cancer immunosurveillance, and the downstream signaling cascades that coordinate immune cell recruitment to the tumor microenvironment to destroy transformed cells through cellular senescence or cell death programs. Its central role in immunosurveillance positions the cGAS-STING pathway as an attractive anti-cancer immunotherapeutic drug target for chemical agonists or vaccine adjuvants and suggests a key node to be targeted in a synthetic lethal approach.

They also discuss adaptive mechanisms used by cancer cells to circumvent cGAS-STING signaling and present evidence linking chronic cGAS-STING activation to inflammation-induced carcinogenesis, cautioning against the use of activating the cGAS-STING pathway as an anti-tumor immunotherapy.

A deeper mechanistic understanding of the cGAS-STING pathway will aid in the identification of potentially efficacious anti-cancer therapeutic targets.

"A deeper mechanistic understanding of the cGAS-STING pathway will aid in the identification of potentially efficacious anti-cancer therapeutic targets"

Dr. Brandon Yi Da Hoong and Dr. Ee Sin Chen from The National University of Singapore said, "When functioning properly, the immune system protects the body against disease and pathogenic attack."

The first line of defense is the innate immune system, which provides nonspecific defense mechanisms, including physical, chemical and immune responses, which protect the organism against microbial insult. Specialized RNA- and DNA-sensing receptors police subcellular compartments for infiltrating foreign nucleic acids, and, upon recognition, trigger immune signaling pathways that initiate a host defense.

These changes lead to the production of type I interferon, which helps to activate the second line of defense, the adaptive immune response.

The innate immune system is triggered by the presence of nucleic acids in the cytoplasm through a range of pattern recognition receptors, including Toll-like receptors, nucleotide-binding oligomerization domain -like receptors, cytosolic DNA sensors, retinoid acid-inducible gene I -like helicases, absent in melanoma 2, DNA-dependent activator of IFN regulatory factors, DEAD box polypeptide 41 , IFNγ-inducible protein 16, Sm-like 14A and Sry-related high-mobility group box 2 and cyclic GMP-AMP synthase /stimulator of interferon genes pathway.

Of the PRRs described, this review will focus on the cGAS/STING pathway, a pathway first identified as a signaling pathway activated by double-stranded DNA during pathogenic infection.

To explore this further, here we describe the cGAS-STING signaling cascade and its extensive downstream activation channels, highlight some of the triggers for pathway activation, outline its diverse roles in carcinogenesis and anti-tumor immunity, and proposes some implications for its potential role in anti-cancer therapy.

The Hoong Research Team concluded in their Oncotarget Research Paper that this review summarizes the critical role of the cGAS-STING pathway in mediating the autophagic, innate, and adaptive immune responses to cytosolic DNA arising from tumor cells.

While there is great potential for using cGAS-STING agonists as anti-cancer agents, their use as clinical therapeutics should proceed cautiously due to the risk of tumorigenesis associated with chronic cGAS-STING activation and non-canonical downstream signaling. Defining the immune profile of tumors and elucidating the pathways controlling the anti- and pro-tumor effects of cGAS-STING activation will pave the way forward for its implementation in anti-cancer therapy.

Membranes with microscopic pores are useful for water filtration. The effect of pore size on water filtration is well-understood, as is the role of ions, charged atoms, that interact with the membrane. For the first time, researchers have successfully described the impact water molecules have on other water molecules and on ions as part of the filtration mechanism. The researchers detail a feedback system between water molecules which opens up new design possibilities for highly selective membranes. Applications could include virus filters.

Synthetic chemistry is a field of study related to the creation and exploration of new substances and materials that do not exist in nature. Sometimes a specific property or behavior of a material is required for an application such as pharmaceutical or high-tech manufacture. Synthetic chemistry can help find, create or refine suitable materials. For example, so-called synthetic liquid crystal membranes could be used for water filtration.

When filtering water or other liquids, the aim is to separate chemical components, such as ions, from your target fluid. Use of a porous membrane can be the primary method for doing this. It's intuitively obvious that holes in a surface will stop anything larger than the hole from passing through. But advanced membranes like synthetic liquid crystal membranes can have pores that are barely a few nanometers, billionths of a meter, across. At these scales, there's more to membrane functionality than just the size of a pore.

"Chemistry plays a big part in what happens at these small scales," said Professor Takashi Kato from the Department of Chemistry and Biotechnology at the University of Tokyo. "In the case of water filtration, the pores are sized to let nothing larger than water pass through. However, there are also electrostatic forces between ions and pores. If the material is engineered correctly, these forces serve as a further barrier to ions even if they're smaller than the pores. This is fairly well-understood. But there is yet another important substance at play that can impact water filtration, and that's actually the water molecule itself."

Professor Yoshihisa Harada from UTokyo's Institute for Solid State Physics and his team had set out to fully describe what has long been suspected but has never been explained before: how water molecules at the site of a pore interact with surrounding water molecules and ions. This is actually very significant at this minute scale, where even subtle forces can impact the overall performance of the filtration membrane. It is also extremely difficult to extract this kind of information from the physical systems.

"In theory we could use computer simulations to accurately model how water behaves and interacts during filtration, but such simulations would require vast amounts of supercomputing power," said Harada. "So at least initially, we turned to a physical method to explore these mechanisms, called synchrotron-based high-resolution soft X-ray emission spectroscopy. This itself was an extremely complex challenge."

This process works by taking X-ray emissions from a synchrotron, a particle accelerator, and directing them to the sample under analysis. The sample, in this case the membrane and water molecules, alters some characteristics of the X-ray beam, before it is detected and recorded by a high-resolution sensor. The changes imposed on the X-ray beam tell researchers what was happening within the sample to a high degree of accuracy.

"It's not easy," said Harada. "Due to the thinness of the membranes, the signals we expected from the target water molecules in the pores are hard to differentiate from the background signals due to the bulk of other water molecules. So we had to subtract the background-level signals to make our target signals more visible. But now I am pleased that we can present the first-ever description of water acting as part of its host material. By performing this kind of basic science, we hope it provides tools for others to build on."

The team's new models describe how water molecules' interactions are modulated by charged particles in close proximity. In membrane pores, water molecules modulated in a certain way preferentially bond with other modulated water molecules in the volume. A dynamic system like this, where a change in some property causes further change in that same property, is known as a feedback loop. Although they can seem mathematically complicated, these models can help engineers create new and effective filtration methods.

"Liquid crystal membranes already have perfectly sized pores, whereas previous kinds of membranes were more varied," said Kato. "Combined with our new knowledge, we aim to create membranes that are even more selective about what they let through than anything that has come before. These could do more than purify water; they might be useful in, for example, construction of lithium-ion batteries, as electrolytes that transport lithium ions between electrodes, and even as a virus filter. As these membranes are so highly selective, they could be tuned to only block very specific things, meaning they could also be used for long periods before becoming saturated."

There are several areas Harada, Kato and their colleagues wish to explore further. These initial physical experiments will inform computer models, so advanced computer simulations are one such area. But they also wish to look at cell membranes which naturally mediate the passage of ions such as potassium and sodium -- studying these could help improve artificial membranes, too.

"What is exciting here is how chemistry, physics and biology combine to elucidate such seemingly complex things," said Harada.