Tech

BELLINGHAM, Washington, USA and CARDIFF, UK - A new paper in Advanced Photonics, an open-access journal co-published by SPIE, the international society for optics and photonics, and Chinese Laser Press (CLP), demonstrates distinct improvements to the inference and generalization performance of diffractive optical neural networks.

One of the key improvements discussed in the paper, "Class-specific differential detection in diffractive optical neural networks improves inference accuracy," incorporates a differential detection scheme combined with a set of parallel-operating diffractive optical networks, where each individual network of this set is specialized to specifically recognize a sub-group of object classes.

According to SPIE Fellow Aydogan Ozcan of the University of California, Los Angeles, and one of the paper's authors, these results "provide a major advancement to bring optical neural network-based low-power and low-latency solutions for various machine-learning applications."

This latest research is a significant advance to Ozcan's optical machine-learning framework: the finessing of this technology is especially significant for recognizing target objects more quickly and with significantly less power than standard computer-based machine learning systems. Ultimately, it may provide major advantages for autonomous vehicles, robotics and various defense-related applications, among others.

These latest systematic advances, in diffractive optical network designs in particular, have the potential to advance the development of next-generation, task-specific, and intelligent computational camera systems.

Over the recent decade, total human impacts to the world's oceans have, on average, nearly doubled and could double again in the next decade without adequate action. That's according to a new study by researchers from the National Center for Ecological Analysis and Synthesis (NCEAS) at UC Santa Barbara.

Published in the journal Scientific Reports, the study assessed for the first time where the combined impacts that humans are having on oceans -- from nutrient pollution to overfishing -- are changing and how quickly. In nearly 60% of the ocean, the cumulative impacts are increasing significantly and, in many places, at a pace that appears to be accelerating.

"That creates even more urgency to solve these problems," said lead author Ben Halpern, director of NCEAS and a professor at UC Santa Barbara's Bren School of Environmental Science & Management.

Climate change is a key factor driving the increase across the world, as seas warm, acidify and rise. On top of that, commercial fishing, runoff from land-based pollution and shipping are intensifying progressively each year in many areas of the ocean.

"It's a multifactor problem that we need to solve. We can't just fix one thing if we want to slow and eventually stop the rate of increase in cumulative impacts," said Halpern.

The study also projected the impacts one decade into the future, based on the rate of change in the recent past, finding that they could double again if the pace of change continues unchecked.

The assessment provides a holistic perspective of where and how much human activities shape ocean change -- for better or worse -- which is essential to policy and planning.

"If you don't pay attention to the big picture, you miss the actual story," said Halpern. "The bigger picture is critical if you want to make smart management decisions -- where are you going to get your biggest bang for your buck."

Regions of particular concern include Australia, Western Africa, the Eastern Caribbean islands and the Middle East, among others. Coastal habitats such as mangroves, coral reefs and seagrasses are among the hardest-hit ecosystems.

There is an upside to the story, however. The authors did find "success stories" around every continent, areas where impacts have declined, such as the seas of South Korea, Japan, the United Kingdom and Denmark, all of which have seen significant decreases in commercial fishing and pollution.

These declines suggest that policies and other actions to improve ocean conditions are making a difference -- although, the analysis does not attribute specific actions to those declines.

"We can improve things. The solutions are known and within our grasp. We just need the social and political will to take action," said Halpern.

To assess the pace of change, the authors leveraged two previous and similar assessments conducted by several of the same team members and others in 2008 and 2013, which provided first glimpses into the full, cumulative extent of humanity's impacts on oceans.

"Previously, we had a good measure of the magnitude of human impacts, but not a clear picture of how they are changing," said co-author Melanie Frazier, a data scientist at NCEAS.

Frazier was surprised to see in the data how dramatically ocean temperatures have increased in a relatively short period of time.

"You don't need fancy statistics to see how rapidly ocean temperature is changing and understand the magnitude of the problem," said Frazier. "I think this study, along with many others, highlights the importance of a concerted global effort to control climate change."

Under the leadership of the head of the laboratory for the synthesis of new crystalline materials of the Samara Center for Theoretical Materials Science (SCTMS) of the Samara Polytech candidate of chemical sciences Eugeny Alexandrov and the head of the department "Chemistry and Technology of Chemical Compounds of Nitrogen", doctor of technical sciences Andrei Pimenov, the synthesis of the first metal-organic polymeric materials, or metal-organic frameworks (MOFs). Recent results of research were published in the scientific journals Dalton Transactions and Chemical Science of publisher
The Royal Society of Chemistry, as well as Crystal Growth & Design of American Chemical Society.

The obtained porous metal-organic frameworks attract the attention of scientists by the fact that they demonstrate record sorption characteristics in relation to various volatile substances, gases, liquids and ions. This is a kind of crystalline sponge, but with unique parameters. One gram of such a substance has a pore surface area comparable to the area of a football field. In addition, they are able to combine several useful properties: magnetic susceptibility, luminescence, electrical conductivity, catalytic activity, and much more. This allows you to create advanced materials for sensors and detectors on their basis, for storing and processing information, photocells, nanoreactors.

«We have a real chance to develop in Samara the technologies for the manufacture of new materials for energy-efficient sorption separation of oil products and industrial gases, as well as for highly selective and highly sensitive chemical sensors, - says the candidate of chemical sciences, head of the laboratory of the center Eugeny Alexandrov. - Development of various aspects (sorption, electrical conductivity, mechanical stability, structure design) of this topic has already been supported by the research grants of the RSF, RFBR and the presidential grant. In addition, applications were sent to two scientific foundations and an industrial partner is being sought.

More than 20 crystal samples of both known and new, not yet studied, porous and electrically conductive metal-organic coordination polymers have been synthesized by the candidate of chemical sciences Andrei Sokolov, Viktor Parfenov, and student Ekaterina Vaganova in the laboratory of the University. These are materials with high porosity, good stability and sorption ability of the components of natural gas, air, gaseous and liquid industrial emissions. Together with the staff of the Department of Physical Chemistry and Chromatography of Samara University (the head of the department, Professor Lyudmila Onuchak), it is planned to manufacture composite materials on their basis and study the surface topography of these composites, their ability to hold various substances on the surface - for example, components of natural gas. Together with the head of the Scientific and Educational Center of Medical Diagnostic Microsystems at the Institute for Innovative Development of Samara State Medical University Andrei Sokolov, it is planned to create chemical sensors and cathode materials for metal-ion batteries based on MOFs.

«I consider these first syntheses of MOFs as a benchmark event in the development of our research center, - said Vladislav Blatov, Professor, Director of SCTMS. - Our center is very young: we are officially approved as a university unit at the very end of 2017. At the same time, in such a short period of time, with the support of the Polytech, we were able to do what we had long dreamed of - to begin the practical implementation of our theoretical forecasts of new crystalline substances and materials in our laboratory».

A new spectroscopic method now makes it possible to measure and visualise the energetic landscape inside solar cells based on organic materials. It was developed by a research team led by Prof. Dr Yana Vaynzof, a physicist at Heidelberg University. This novel visualisation technique enables scientists to study the physical principles of organic photovoltaics with extreme precision and to better understand processes such as energetic losses.

"Mapping our Earth's landscapes was a necessary step for understanding the movement patterns and dynamics of people, animals and water, among other examples", explains Prof. Vaynzof, research group leader at the Kirchhoff Institute for Physics at Heidelberg University. "Similarly, the movement of electric charges in a solar cell is determined by the energetic landscape within the device." Until now, visualising these energetic landscapes was so challenging that only rough estimates could be used to study the fundamental processes in organic photovoltaic devices.

The spectroscopic method developed by the Heidelberg researchers can map the energetic landscape on a nanometre scale and can be applied at any point during the solar cell's lifetime. "The strength of our method lies in its excellent resolution and great versatility", says Vincent Lami, member of Prof. Vaynzof's team and the lead author of the study. According to Prof. Vaynzof, their work solves a key problem in the field of organic photovoltaics. "Without mapping the energetic landscapes, it is difficult to understand how and why devices lose energy in the process of converting light into electricity. Now we have a spectroscopic method that allows us to develop new generations of solar cells with reduced energy losses and improved performance", emphasises the scientist, who heads the "Organic Electronics" research group at the Kirchhoff Institute for Physics and works at the Centre for Advanced Materials of Heidelberg University.

COLUMBUS, Ohio - Racial and ethnic gaps in criminal sentences have declined, in some cases significantly, since the mid-1990s, a new analysis of state, county and federal data suggests.

For example, the overall sentence length gap between whites and blacks in federal courts decreased by more than 80 percent between 1996 and 2016.

The analysis also found declines in the disparity between how often blacks are sentenced to prison compared to whites.

While many studies have noted the differences in the sentencing of blacks and Hispanics compared to whites, this analysis is one of the first to examine how this has changed over time, said Ryan King, co-author of the new work and professor of sociology at The Ohio State University.

King said the findings surprised him.

"Before we did this analysis, I thought the racial and ethnic gap would stay pretty flat or maybe even increase slightly," he said.

"These results show we have a reason for optimism. I don't want to be a Pollyanna. But if our goal is to have an equitable criminal justice system, we should acknowledge the progress that has been made, while being mindful that there still is a gap."

King conducted the analysis with Michael Light, associate professor of sociology and Chicano/Latino studies at the University of Wisconsin-Madison. They presented their results Aug. 13 in New York City at the annual meeting of the American Sociological Association.

Some of the results were also reported earlier in Crime and Justice: A Review of Research.

The researchers used three data sets that collectively include more than 2 million criminal cases dating back to the 1980s or 1990s, depending on the source.

The data sets are federal sentencing data from 1992 to 2016; Minnesota Sentencing Guideline Commission data from 1981 to 2017; and State Court Processing Statistics data between 1990 and 2009, which consists of data from large urban counties in 25 states across the country.

The three data sets are quite different, but "they all tell a pretty consistent story - not identical, but similar," King said.

"I think what surprised me most was the trend in the federal system and how much it has changed since about 2009," he said.

In 1992, blacks were sentenced to roughly 27 more months in prison than whites, increasing to a difference of 42 months in 1996. Since then, the difference has dropped dramatically. In 2016, the gap was only eight months - an 80 percent reduction from 20 years earlier.

But other statistics also showed improvement, such as a reduction in the race gap relating to the probability of going to prison rather than getting probation or another kind of sentence.

In 1996, blacks in the federal system were nearly 14 percent more likely to receive a prison sentence than were whites. That gap was halved, to about 7 percent, in the mid-2000s.

The researchers examined other ways of looking at sentencing trends to see if they also showed a decline in the racial gap.

In one analysis, King and Light examined what is called the presumptive sentence. The federal system and some states give judges guidelines to follow when determining what the appropriate or typical sentence should be for a particular crime, taking into account factors such as the severity of the crime and the perpetrator's criminal history.

They found that in 1992, whites in the federal system received only 81 percent of the recommended prison sentences on average, while blacks received 90 percent of their presumptive sentences - a 9 percent difference. That difference shrunk slightly - to 6 percent - by 2016, results showed.

The results for Hispanics were more complex and reflected a tale of two groups: citizens and noncitizens.

"When you look at the sentencing disparities between Hispanics and whites, overall they are very large. But when you pull out the noncitizens and look only at citizens, it tells a different story," King said.

Hispanics, including non-citizens, were 17 percent more likely than whites to be incarcerated relative to their presumptive sentence in 1992 in the federal system, increasing to 26 percent in 2016.

But if you look only at U.S. citizens, the disparity is much smaller and trending toward more equality with whites, King said.

"Excluding immigration offenses, being a Hispanic noncitizen greatly increases the probability of going to prison for the same crime compared to Hispanic citizens," he said.

This trend started long before the Trump administration, King noted.

The gap in sentence length between non-Hispanic whites and Hispanics has consistently stood at 5 percent or less, and by 2016 there was practically no disparity between the groups in the federal system.

Several factors may have contributed to the decline in the racial sentencing gap, according to King.

On the federal level, the election of Barack Obama in 2008 and appointment of the first black attorney general likely played a role.

The Fair Sentencing Act of 2010, which reduced the disparity in sentences for crack versus powder cocaine, was also a key, because blacks were much more likely to be convicted under the much harsher crack-cocaine penalties.

But the data from the Minnesota court system and the State Court Processing Statistics show the progress in reducing the gap goes beyond these federal trends.

"It isn't just the result of federal policy changes and decisions by key people in powerful positions," King said. "There's more contributing to this trend."

One contributor may have been more media attention to the racial gap issue, particularly after 2000. That message reached the legal community.

For example, the Minnesota data showed that, over time, judges were increasingly giving sentences to blacks that were shorter than the guidelines recommended.

"I think it may have been changes in judicial norms. Judges don't want racial disparities. They may have observed it happening and made adjustments along the way, trying to be more equitable," King said.

But the research results don't mean that there isn't work yet to be done, he said.

"We've come a long way in the United States, but the gap hasn't disappeared."

New research reveals the emotional journey that tourists go on when they disconnect from technology and social media while travelling.

The study, by the University of East Anglia (UEA), University of Greenwich and Auckland University of Technology (AUT), investigated how engaging in digital-free tourism impacted travellers' holiday experiences. It involved losing access to technologies such as mobile phones, laptops, tablets, the Internet, social media and navigation tools.

The researchers, who also took part in the study themselves, examined participants' emotions before they disconnected, during their disconnection, and after they reconnected.

Published in the Journal of Travel Research, the findings show there were initial anxiety, frustration and withdrawal symptoms among many of the travellers, but later growing levels of acceptance, enjoyment, and even liberation.

The findings come as the demand for so-called 'digital detox' holidays is on the rise. Lead author Dr Wenjie Cai, from the University of Greenwich Business School, said: "In the current ever-connected world, people are used to constant information access and various services provided by different applications.

"However, many people are increasingly getting tired of constant connections through technologies and there is a growing trend for digital-free tourism, so it is helpful to see the emotional journey that these travellers are experiencing.

"Our participants reported that they not only engaged more with other travellers and locals during their disconnected travels, but that they also spent more time with their travel companions."

As well as looking at emotions Dr Cai, working with Dr Brad McKenna of UEA's Norwich Business School and Dr Lena Waizenegger from AUT, used the theory of affordance to understand the loss or gain of technological opportunities while travellers engage in digital-free tourism. For example, Google Maps affords navigation and when taken away, the participants lost the ability to navigate, which caused anxiety for some.

Dr McKenna said the findings have valuable implications for tour operators and destination management organisations to gain a better understanding of travellers' emotions when developing 'off-the-grid' packages or tech-savvy tour products.

"Understanding what triggers consumers' negative and positive emotions can help service providers to improve products and marketing strategies," said Dr McKenna. "The trips our travellers took varied in terms of lengths and types of destinations, which provides useful insights into various influencing factors on emotions.

"We found that some participants embraced and enjoyed the disconnected experience straightaway or after struggling initially, while for others it took a little bit longer to accept the disconnected experience.

"Many also pointed out that they were much more attentive and focused on their surroundings while disconnected, rather than getting distracted by incoming messages, notifications or alerts from their mobile apps."

In total 24 participants from seven countries travelled to 17 countries and regions during the study. Most disconnected for more than 24 hours and data was collected via diaries and interviews.

By talking to other travellers, especially locals, many reported that they were given excellent advice and learned more about sights, places and beaches that were not on any tourism websites or guidebooks, but were a highlight of their trips.

Once reconnected, many participants said they were upset and overwhelmed as soon as they saw all the incoming messages and notifications they received over the days they were disconnected. However, having enjoyed the engagement with locals and physical surroundings during disconnection, some decided to have another digital detox in the future.

Various factors affected how travellers perceived the digital-free tourism experience. Participants suffered anxieties and frustrations more in urban destinations due to the need for navigation, instant information access, and digital word-of-mouth recommendation seeking. Those in rural and natural destinations, on the other hand, tended to have withdrawal symptoms related to being unable to report safety or kill time.

Participants travelling as a couple, or in a group, tended to be more confident to disconnect than solo travelers. They reported suffering less or even had no negative withdrawal symptoms when travelling with companions who are connected; while solo travellers tended to feel vulnerable without technological assistance to buffer cultural differences, such as an unfamiliar language.

On a personal level, withdrawal symptoms tended to be stronger for travellers who participated in digital-free tourism with many social and professional commitments. They were also more likely to have negative disconnected experiences. Some participants tried, but could not disconnect during their travels either because they did not feel secure and thought they would get lost, or because they had private commitments that did not allow them to be unavailable.

Tropical Storm Krosa is a large tropical cyclone. When NASA-NOAA's Suomi NPP satellite passed over the Northwestern Pacific Ocean, it captured a visible image of the massive storm.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Tropical Storm Krosa on Aug. 12 at 12:30 a.m. EDT (0430 UTC). The VIIRS image showed that the storm appeared to be almost as wide as the length of the Philippines. For comparison, the Philippines' length is 1,851 km (1,150 miles) from south-southeast to north-northwest. Thunderstorms wrapped around the low-level center and a band of fragmented thunderstorms stretched far to the south of the center of circulation.

The Joint Typhoon Warning Center noted in their discussion on Aug. 12, "Animated enhanced infrared satellite imagery shows a very expansive system deep but widely fragmented convective bands spiraling in mostly from the southwest into a large, ragged and fully exposed low-level circulation."

At 11 a.m. EDT (1500 UTC) on Monday, August 12, 2019, the Joint Typhoon Warning Center found Krosa's maximum sustained winds near 55 knots (63 mph/102 kph). Krosa's large eye was centered near 26.1 degrees north latitude and 136.7 degrees east longitude. That's about 236 nautical miles west-northwest of Iwo To island, Japan. Krosa was moving to the northwest.

Krosa is expected to make landfall over western Shikoku, Japan in two and a half days, on August 15. Shikoku is the smallest of Japan's major islands.

The largest study ever conducted of its kind has identified where and how to save coral reef communities in the Indo-Pacific, according to an international group of scientists from WCS (Wildlife Conservation Society) and other conservation NGOs, government agencies, and universities. The study outlines three viable strategies that can be quickly enacted to help save coral reefs that are threatened by climate change and human impacts.

Published today in the journal Nature Ecology and Evolution, the study involved the efforts of more than 80 authors who surveyed coral abundance on more than 2,500 reefs across 44 countries in the Indian and Pacific Oceans. The findings revealed that the majority of reefs had functioning coral communities with a living cover of architecturally complex species that give reefs their distinctive structure. After the damage caused by severe heat stress during the 2014-17 El Niño event, the authors found nearly 450 reefs in 22 countries across the Indo-Pacific that survived in climate 'cool spots' that should be prioritized for urgent protection and management.

The landmark publication also presents a conservation framework of three management strategies (protect, recover, and transform) to safeguard reef ecologies and ecosystem services into the future.

"The good news is that functioning coral reefs still exist, and our study shows that it is not too late to save them," said WCS Conservation Scientist Dr. Emily Darling, lead author of the study and leader of WCS's global coral reef monitoring program. "Safeguarding coral reefs into the future means protecting the world's last functioning reefs and recovering reefs impacted by climate change. But realistically - on severely degraded reefs - coastal societies will need to find new livelihoods for the future."

Good news on corals has become rare in the 21st Century as increasing carbon emissions and human impacts of overfishing, pollution and unsustainable development have led to predictions of a bleak future for tropical reefs and the millions of people who depend on them. The Indo-Pacific, a hotspot of coral reef biodiversity, in particular has been devastated by periods of severe heat stress and mass coral bleaching events in 1983, 1998, 2005, 2010, and most recently in the world's longest, largest and most intense bleaching event in 2014-2017.

The study also identifies the minimum requirements to save functioning reefs. This required evaluating the impacts of 20 environmental, climatic, and human-caused stressors on reef-building corals. The authors found that higher abundances of framework corals, the species that build the backbone of coral reefs, occurred in locations with fewer climate shocks and longer recovery windows. Higher coral abundances were also found farther from coastal populations and their associated markets and agricultural impacts.

The authors' findings helped to formulate the three strategic choices of management for the reefs.

Protect: 17 percent of coral reefs in the study's dataset had functioning coral reefs and occurred in a climate 'cool spot' during the 2014-2017 El Niño. The reefs are found in 22 countries from East Africa to South East Asia, the Coral Triangle, and the Pacific. These findings call for an international network of coral reef conservation to save the world's last functioning coral reefs.

Recover: The second strategy is to promote rapid coral recovery where reefs (54 percent of those examined in the study) were previously functioning but have been recently impacted by the 2014-2017 coral bleaching event.

Transform: The third strategy recognizes that some coastal societies will need to transform away from dependence on reefs that are no longer functioning (28 percent of the reefs analyzed fell into this category).

The study's findings stress that strategic local management can play a role in helping protect corals through tools such as marine protected areas or other management restrictions that reduce threats and keep coral reefs above functional thresholds. However, the authors noted that local management can complement but not replace the need for worldwide efforts to limit carbon emissions.

"Saving reefs will require combining local and global efforts, such as reducing local dependence on reef fish to maintain a reef's important functions while also reducing carbon emissions to keep warming below 1.5 degrees Celsius," said Dr. Tim McClanahan, WCS Senior Conservation Zoologist and co-author of the study.

Said Dr. Georgina Gurney from the ARC Centre of Excellence for Coral Reef Studies, James Cook University: "While coral reef sustainability depends largely on reducing carbon emissions, identifying reefs that are likely to respond - or importantly, not respond - to local management is critical to targeting development and management strategies to build the well-being of the millions of people dependent on coral reefs across the globe."

Said Gabby Ahmadia, director of marine conservation science at World Wildlife Fund and co-author of the study: "More than ever, we must consider how to manage local threats to coral reefs while keeping an eye to future climate impacts. This study will help policymakers and conservationists make informed management decisions for coral reefs and the communities that rely on them."

Irvine, Calif., Aug. 12, 2019 -- When Joleah Lamb strapped on a scuba tank and plunged into the ocean over a decade ago, it was the first of many expeditions to examine the effects of climate change and other human-produced factors on coral.

Now, 13 years after that foray, she has contributed one of the largest amounts of data to a landmark study on how to save coral reefs in the Indian and Pacific Oceans. Lamb, an assistant professor of ecology & evolutionary biology at the University of California, Irvine School of Biological Sciences, is among more than 80 marine researchers worldwide who produced the report. It has been published in Nature Ecology and Evolution.

The research encompassed over 2,500 reefs across 44 countries. Lamb provided its fourth-largest dataset, containing details on more than a million individual corals. Gathering the information required painstaking visual inspection, with Lamb and colleagues swimming underwater for as much as six hours each day. Armed with special measuring tapes, waterproof paper and pencils, they recorded information on each coral, meticulously identifying the size and health of more than 300 unique species.

Key to this study were observations of bleaching, a visible indication water is too warm. When temperatures rise, corals expel algae they normally depend on for energy. The depletion robs the corals of their color and turns them white. It also eventually starves them.

"There are efforts to use drones or satellites to collect this information, but you cannot get the high resolution needed to assess the vital complex architecture of reefs unless you are in the water," said Lamb.

The scientists involved in the report say it's not too late to save reefs if three strategies are immediately enacted in the Indo-Pacific. One is protecting from human impact those that are functioning, representing 17 percent of the reefs studied. Another is helping the 54 percent that are damaged but have the potential to recover. For 28 percent, it may be too late for rescue, which suggests some coastal societies will need to transition away from depending on them.

Lamb says Americans should be concerned about the research results. "There are a lot of reefs in our territories, such as Hawaii, American Samoa and Guam," she said. "They all face severe impacts from the loss of coral reefs, including on coastal protection, food and income from tourism. And even if you don't live close to a reef, carbon emissions contribute to climate change that harms corals worldwide."

Besides university scientists, researchers with the Wildlife Conservation Society, other non-profit organizations and governmental agencies participated in the study. The massive project demonstrates the need for collaboration in combatting environmental threats, she said.

"As scientists, we can tend to work in small domains and become microscopic in what we examine," she added. "We can't be that way anymore. We must work together on large global solutions that protect our world."

BINGHAMTON, N.Y. - A research team including faculty at Binghamton University and University of Colorado Denver are the first to map the molecular structure of an aggressive protein aggregate that causes acceleration of Alzheimer's disease.

"Approximately 10 percent of Alzheimer's cases result from familial mutations," said Wei Qiang, assistant professor of biophysical chemistry at Binghamton University. "The other 90 percent cases are caused by misfolded wild-type amyloid proteins. We need to understand the molecular basis of the disease pathology. In doing so, we might one day create drugs that prevent the degenerative effects of the disease."

Alzheimer's disease starts developing when toxic protein fragments called beta amyloids form into chains known as fibrils, which build upon and kill brain cells. Qiang, along with researchers at the University of Colorado Denver, used high-resolution solid-state nuclear magnetic resonance spectroscopy to study these fibrils. Their work revealed that these fibrils may possess major variations in the molecular structure of amyloid depositions in the human brain. More importantly, the fibrils could serve as "seeds" for further fibril deposition, which is a potential risk factor in Alzheimer's pathology. 

"This work describes a molecular structural model for a pathologically relevant beta-amyloid fibril variant," said Qiang. "We showed that this variant could lead to rapid seeding of new amyloid fibrils, which potentially contributes to the spreading and amplification of amyloid deposition in human brains."

Qiang and his team are looking at several other types of fibril variants and specifically, the correlation between the structural variations, their seeding abilities and the resulted cellular toxicity levels.

"We have already obtained exciting results and a new manuscript describing these further finding is in preparation," said Qiang.

In discussions of anthropogenic climate change, carbon dioxide generally gets the spotlight, but it is not the only greenhouse gas spewed into the atmosphere by human activity, nor is it the most potent.

Methane is another greenhouse gas that is increasing in Earth's atmosphere because of humans. Methane is produced by human activity in much smaller amounts than carbon dioxide, but it is roughly 25 times more powerful as a greenhouse gas. Though it is often associated with cow flatulence, bovines are not the only human-associated source of methane.

New research by Caltech scientists shows that, at least in the Los Angeles Basin, leaks of natural gas used for heating homes and businesses are major contributors to methane in the atmosphere.

The research was conducted by Liyin He (MS '18), a graduate student in environmental science and engineering, while working in the lab of Yuk L. Yung, Caltech professor of planetary science and research scientist at the Jet Propulsion Laboratory, which Caltech manages for NASA. She found that methane concentrations in the air above L.A. fluctuate in tandem with the seasons. In winter, when natural gas use is at its highest, methane concentrations are also highest. In the summer, when natural gas use drops, so does the amount of methane in the air.

"Naturally, methane emissions should be pretty flat across the seasons, but maybe a little higher in the summer period because of a lot of things decompose from higher temperatures," He says. "But it seems that in the city, natural gas consumption is so high in the winter that a lot of it leaks into the atmosphere."

He conducted her research by using a device called a remote-sensing spectrometer atop Mt. Wilson, a mountain whose peak towers a mile above Los Angeles. From its lofty perch, the spectrometer had a view of a wide swath of the urban area below. Methane is invisible to human eyes, but it is easily seen by the spectrometer because it strongly absorbs infrared light, the wavelength of light to which the spectrometer is sensitive.

Using this setup, the spectrometer was pointed at 33 surface sites around the region and collected methane measurements six to eight times a day for six years. When those measurements were aggregated, a clear pattern emerged: methane levels in the atmosphere peaked each December and January and dipped to a low each June and July.

Though He's research does not identify specific sources of methane, she says that it is likely that the entire natural gas distribution system, from storage fields to pipelines to stoves and furnaces, is responsible for the leaks.

Because methane is such a potent greenhouse gas, and because it is relatively short-lived in the atmosphere, identifying and reducing those natural gas leaks is one way humans might help reduce the effects of climate change, He says.

"Agriculture and wetlands are still the most important sources of methane when we consider the global scale, He says. "But I think pipeline leakage is the most important one when it comes to cities."

PROVIDENCE, R.I. [Brown University] -- Tree-like branching structures are everywhere in the human body, from the bronchial system in the lungs to the spidering capillaries that supply blood to the extremities. Researchers have long worked to understand the cellular signaling needed to build these intricate structures, but new research suggests that simple physics may play an underappreciated role.

The research, published in the Proceedings of the National Academy of Sciences, shows that under certain circumstances, human epithelial cells behave according to the rules of diffusion-limited aggregation, a theory explaining the self-assembly of particles suspended in a liquid. The study showed that cells cultured at sparse densities and low amounts of growth factor arrange themselves in fractal-like branching clusters. The fractals (patterns in which tiny subsections look the same as the whole) have nearly the exact dimensions predicted by diffusion-limited aggregation.

"What's remarkable to me is that you have this elegant physical theory that describes the aggregation of sticky particles moving randomly and also explains the behavior of migrating cells," said Ian Y. Wong, an assistant professor in Brown University's School of Engineering and senior author on the paper. "In actuality, cells are complicated entities with many ways to send and receive signals, yet in this case they seem to follow the same rules as much simpler, non-living particles."

The findings could offer insights into the formation of branching structures in the body as well as other key biological processes, said Susan E. Leggett, currently a postdoctoral researcher at Princeton University and the study's lead author.

??"We think this could potentially tell us something about tissue formation, wound healing, cancer invasion and other processes in which moving cells organize into multicellular tissues," said Leggett, who performed the work as a Ph.D. student in pathobiology at Brown.

When she started the research, Leggett was actually thinking about a very different question. She wanted to learn more about how cells behave when they're on their own, away from the influence of their neighbors. She's interested in a process known as the epithelial to mesenchymal transition (EMT) in which clustered epithelial cells transition into more motile mesenchymal cells. The transition tends to happen when cells are isolated from each other.

"My original motivation for seeding cells in these low-growth-factor conditions was to maintain them in a low-density environment so we could study EMT," Leggett said. "We didn't anticipate that the cells would undergo this aggregation, which is almost the reverse process."

The cells in the low-density cultures moved around randomly until they came into contact with another cell, at which point the cells stuck together and stopped moving. Over the course of a few days, the clustered cells assembled themselves into long branch-like structures that were "strikingly reminiscent of fractal-like structures associated with diffusion-limited aggregation," the researchers wrote.

Further analysis showed that the fractal dimension of cell clusters (a measure of how densely packed the branches are) came out to around 1.7, which is precisely the fractal dimension measured experimentally and predicted theoretically for the diffusion-limited aggregation of particles.

The fact that the cells formed structures so similar to that of inanimate matter could be helpful in understanding how and why branched architectures are so prominent in biology, the researchers said.

"An improved understanding of these collective behaviors may further enable new design rules for programming cells to assemble into larger tissue architectures," Wong said.

Two studies led by the Garvan Institute of Medical Research have revealed that nitrogen-bisphosphonates, drugs commonly prescribed for osteoporosis, reduced the risk of premature mortality by 34% in a cohort of over 6,000 individuals. This reduction in early mortality risk was significantly associated with a reduction in bone loss compared with no treatment.

The findings present new advice of the significant benefits of taking approved osteoporosis medicine for those at risk of osteoporosis, and their health care professional.

After the age of 50, 40% of women and 25% of men will sustain an osteoporotic fragility fracture in their life, an injury that puts them at risk of further fractures. However, currently fewer than 30% of women and 20% of men with fragility fractures are taking approved treatments for osteoporosis.

"It's a common misconception that osteoporosis affects only women, and many people choose to not take recommended treatments," says Professor Jacqueline Center, who heads the Clinical Studies and Epidemiology laboratory at the Garvan Institute and is an Endocrinologist at St Vincent's Hospital, who led the studies. "But osteoporotic fractures are not benign. Osteoporosis medication not only decreases the risk of further fractures - but it appears that this same medication also decreases mortality rates over the subsequent 15 years."

Reduction in mortality risk

Osteoporosis affects around 200 million people worldwide, and is a progressive disease in which bones become more porous and fragile, often without symptoms until the first fracture occurs.

A Garvan-led team of international researchers analysed data from a cohort of 6,120 participants aged over 50, who took part in the observational Canadian Multicentre Osteoporosis Study.

The analysis showed that individuals treated with nitrogen-bisphosphonates (alendronate or risedronate) had a 34% reduction in mortality risk over the subsequent 15 years, compared to non-treated individuals. The study was published in the April issue of the journal Osteoporosis International(1).

In a second follow-up study, published in the Journal of Bone and Mineral Research, the team analysed data from a cohort of 1,735 women, from the same study. The analysis revealed that 39% of the reduction in premature mortality risk was mediated through a reduction in the rate of bone loss.

The researchers also directly compared the nitrogen-bisphosphonates (alendronate or risedronate) with a weaker, non-nitrogen bisphosphonate and found a similar reduction in mortality risk benefit with the nitrogen-bisphosphonates.

The study provides additional evidence that nitrogen-bisphosphonate treatment can provide significant benefits for those with osteoporosis and is the first to examine potential mechanisms.

"For many individuals with osteoporosis, bone health isn't front-of-mind," says first author of both studies, Garvan's Dr Dana Bliuc, Research Officer in the Clinical Studies and Epidemiology laboratory. "We hope our study results will encourage people with osteoporosis or at risk of a fracture to seek treatment - and commit to taking it."

The debate can finally be put to rest--Lil Nas X's record-setting, chart-topping hit "Old Town Road" is indeed country. But it's also a little rock 'n roll. And when you analyze the lyrics and chords together, it's straight-up pop.

At least, that's according to an artificial intelligence tool developed by USC computer science PhD student Timothy Greer. Greer's method automatically predicts music genres by analyzing how lyrics and chords interact with one another throughout the song.

The method classified "Old Town Road" as country according to the lyrics; rock according to the chords (based on a Nine Inch Nails music sample); and pop according to the chords and lyrics combined.

The paper, titled "Using Shared Vector Representations of Words and Chords in Music for Genre Classification," will be presented at the Speech, Music and Mind 2019 conference on Sept.14.

A Very Human Experience

"Old Town Road is an interesting song," said Greer, a lifelong musician who currently plays saxaphone and keyboard in an LA-based band (music genre: Indie rock).

"The lyrics are steeped in the country genre, but the chords and the instrumentation don't sound like country at all. The algorithm highlights the complexity of music, both in terms of how the music is constructed and how it is perceived, in other words, how people process it."

This effort in music research--to computationally understand the stories we tell with it, and how people experience and are influenced by it--is a part of a larger research program in Computational Media Intelligence at USC Signal Analysis and Interpretation Laboratory (SAIL) (SAIL).

"Music construction and perception are related, but they are not one and the same," said Greer's supervisor and paper co-author Shrikanth Narayanan.

Narayanan, SAIL director and the Niki and Max Nikias Chair and Professor of Electrical and Computer Engineering, has previously analyzed vocal patterns of beatboxers and opera singers using MRI scans, predicted violence ratings using movie scripts and developed technology that uses voice to assess speaker emotions. He said he is excited about this new research because it's a new way of analyzing music computationally and could reveal unexpected patterns.

"We always say there is no hard-set rule for human experiences of music," said Narayanan, a classical music enthusiast who plays the Indian stringed instrument veena and the violin. "AI and machine learning can provide a lens from which to look at this very human experience."

A New Sound

"Old Town Road," which has now been at the top of the charts for 18 weeks, has been notable for its genre-blending characteristic. As one of the most hotly debated topics in the pop world this summer, everyone seems to have a different opinion--is it country, pop, rock? Or something else altogether?

In April 2019, the song was removed from the Billboard Hot Country chart because it did "not embrace enough elements of today's country music to chart in its current version," according to a Billboard statement.

Greer put the song to the test with three models he had developed to predict genre: using only chord embeddings, only lyric embeddings and using chord-and-lyric embeddings combined. He trained the system on a dataset with 190,165 musical segments from 5,304 pop songs with lyrics and corresponding chords.

While most genre prediction tools use a song's entire audio file, which means retrieving and processing a high-quality recording, Greer's method can classify genre using only chords and lyrics, which are usually available online with a quick Google Search.

"This interplay between chord sequences and lyric sequences may give us a better glimpse into how we perceive genre than using either alone, although both of these modalities contains useful information alone, as well," said Greer.

The study gives a better understanding of how we perceived and process music, specifically the differences in human music perception--and categorization--of music genre depending on the "looking glass" used.

Applications include how music content is marketed, consumed and tagged; neuropsychology and the mechanisms of human thought; and affective computing systems that impact human emotions.

The greater frequency of droughts, combined with underlying economic, social, and environmental risks means that dry spells have an increasingly destructive impact on vulnerable populations, and particularly on children in the developing world. In a new study by researchers from IIASA and the USA, the team set out to map at-risk populations at the global scale.

Temperature extremes and erratic rainfall patterns associated with climate change are affecting food production and infrastructure critical to food distribution, which in turn directly impact nutrition outcomes. One in nine people around the world are currently under-nourished and nearly half of the deaths in children under five are caused by poor nutrition. The burden is particularly heavy in Africa and parts of South Asia, where conflict, political fragility, and drought are more prevalent. Drought in particular, takes a heavy toll on poor communities, and especially on children in developing countries where a large part of the population's livelihoods are dependent on subsistence farming and rain-fed agriculture. One of the consequences of poor child nutrition is stunting - in other words, impaired growth and development - which currently affects at least one in three children in these parts of the developing world.

Stunting has many adverse effects on children including a higher risk of mortality, reduced physical, cognitive, and educational attainment, and lifelong health problems from reduced immunity and increased disease susceptibility. A factor that makes addressing child stunting a critical component of sustainable development, is the fact that the effects of stunting on a population are long-term and in many cases also transgenerational, thus hampering future economic growth in populations where it is most needed. While rates of stunting have been in decline globally over the past few decades, increased climate shocks due to climate change could stall or even reverse the progress made to date. It is therefore important that populations at risk of the effects of drought be identified so that mitigation efforts can be targeted and deployed for maximum effectiveness.

Because data on stunting has been collected at fine spatial scales over decades, it is possible to explore in detail which areas are most vulnerable to climate shocks and which factors influence vulnerability. The authors of the study published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), however note that, while it is relatively easy to identify populations vulnerable to the climate impacts of, for instance, sea-level rise, not enough work has been done to identify populations vulnerable to the effects of drought on food availability and nutrition. According to the researchers, previous attempts to map the vulnerability of food systems did not incorporate historic observations of climate shocks and nutrition outcomes. The study improves on these approaches by using over 580,000 observations of children from 53 countries to examine how rainfall extremes have affected nutrition outcomes since 1990. This unusually large malnutrition data set was processed and analyzed in the Microsoft Azure cloud using resources provided from a Microsoft AI for Earth grant. The results indicate that rainfall extremes and drought are specifically associated with worse child nutrition, but also that these effects can be mitigated or amplified by several factors.

"We found that a number of factors can make children resilient to droughts, such as good governance, nutritionally diverse crops, higher levels of imports per capita, overall crop production, and irrigation," explains study lead-author Matthew Cooper, who started this work as part of the 2018 IIASA Young Scientists Summer Program. "By assessing all of these factors quantitatively, we were able to identify the places that were the most vulnerable to drought. These were predominantly arid, poorly governed countries with little trade, including Chad, Eritrea, Somalia, South Sudan, Sudan, and Yemen."

Cooper says that one of the most interesting findings of this study is that nutritionally diverse cropping systems can provide a lot of resilience. This information could help global actors like the UN Food and Agriculture Organization or the World Health Organization to get a sense of where to target aid and where populations expected to be the most vulnerable to droughts are situated. The factors that create resilience can also be useful to development practitioners and NGOs working in drought-vulnerable countries in terms of highlighting the benefits of advocating for and implementing nutritionally diverse farming systems as a way to improve drought resilience.

"Beyond being of practical relevance to development practitioners and other policymakers, this work shows how much just one of the main effects of climate change - more severe and more frequent droughts - will impact especially children in poor countries, who have not contributed to the climate change problem themselves. This is a grave injustice that needs to be addressed," concludes Cooper.