Global cooling event 4,200 years ago spurred rice's evolution, spread across Asia

Scientists use genomics, archeology, and climate data to reconstruct history of rice

NEW YORK UNIVERSITY

IMAGE: A SIMPLIFIED MAP SHOWS THE SPREAD OF RICE INTO BOTH NORTHERN AND SOUTHERN ASIA FOLLOWING A GLOBAL COOLING EVENT APPROXIMATELY 4,200 YEARS BEFORE PRESENT (YBP). view more 

CREDIT: RAFAL GUTAKER, NEW YORK UNIVERSITY

A major global cooling event that occurred 4,200 years ago may have led to the evolution of new rice varieties and the spread of rice into both northern and southern Asia, an international team of researchers has found.

Their study, published in Nature Plants and led by the NYU Center for Genomics and Systems Biology, uses a multidisciplinary approach to reconstruct the history of rice and trace its migration throughout Asia.

Rice is one of the most important crops worldwide, a staple for more than half of the global population. It was first cultivated 9,000 years ago in the Yangtze Valley in China and later spread across East, Southeast, and South Asia, followed by the Middle East, Africa, Europe, and the Americas. In the process, rice evolved and adapted to different environments, but little is known about the routes, timing, and environmental forces involved in this spread.

In their study, the researchers reconstructed the historical movement of rice across Asia using whole-genome sequences of more than 1,400 varieties of rice--including varieties of japonica and indica, two main subspecies of Asian rice--coupled with geography, archaeology, and historical climate data.

For the first 4,000 years of its history, farming rice was largely confined to China, and japonica was the subspecies grown. Then, a global cooling event 4,200 years ago--also known as the 4.2k event, which is thought to have had widespread consequences, including the collapse of civilizations from Mesopotamia to China--coincided with japonica rice diversifying into temperate and tropical varieties. The newly evolved temperate varieties spread in northern China, Korea and Japan, while the tropical varieties and spread to Southeast Asia.

"This abrupt climate change forced plants, including crops, to adapt," said Rafal M. Gutaker, a postdoctoral associate at the NYU Center for Genomics and Systems Biology and the study's lead author. "Our genomic data, as well as paleoclimate modeling by our collaborators, show that the cooling event occurred at the same time as the rise of temperate japonica, which grows in milder regions. This cooling event also may have led to the migration of rice agriculture and farmer communities into Southeast Asia."

"These findings were then backed up by data from archaeological rice remains excavated in Asia, which also showed that after the 4.2k event, tropical rice migrated south while rice also adapted to northern latitudes as temperate varieties," said Michael D. Purugganan, the Silver Professor of Biology at NYU, who led the study.

After the global cooling event, tropical japonica rice continued to diversify. It reached islands in Southeast Asia about 2,500 years ago, likely due to extensive trade networks and the movement of goods and peoples in the region--a finding also supported by archeological data.

The spread of indica rice was more recent and more complicated; after originating in India's lower Ganges Valley roughly 4,000 years ago, the researchers traced its migration from India into China approximately 2,000 years ago.

While the researchers had thought that rainfall and water would be the most limiting environmental factor in rice diversity, they found temperature to be the key factor instead. Their analyses revealed that heat accumulation and temperature were very strongly associated with the genomic differences between tropical and temperate japonica rice varieties.

"This study illustrates the value of multidisciplinary research. Our genomic data gave us a model for where and when rice spread to different parts of Asia, archaeology told us when and where rice showed up at various places, and the environmental and climate modeling gave us the ecological context," said Purugganan. "Together, this approach allows us to write a first draft of the story of how rice dispersed across Asia."

Understanding the spread of rice and the related environmental pressures could also help scientists develop new varieties that meet future environmental challenges, such as climate change and drought--which could help address looming food security issues.

"Armed with knowledge of the pattern of rice dispersal and environmental factors that influenced its migration, we can examine the evolutionary adaptations of rice as it spread to new environments, which could allow us to identify traits and genes to help future breeding efforts," said Gutaker.

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In addition to Purugganan and Gutaker, study authors include other members of the Purugganan laboratory at the NYU Center for Genomics and Systems Biology, and collaborators at Pennsylvania State University, Universidade Nova de Lisboa in Portugal, the Crow Canyon Archaeological Center, Carnegie Mellon University, the University of Manitoba, University College London, North-West University in China, University College Dublin, and the University of California San Diego.

The research at NYU was supported by the Zegar Family Foundation and the National Science Foundation Plant Genome Research Program (IOS-1546218).

RELEASE 15-MAY-2020

Early humans thrived in this drowned South African landscape

The Paleo-Agulhas Plain had diverse, verdant ecosystems and abundant game

UNIVERSITY OF CALIFORNIA - RIVERSIDE

Early humans lived in South African river valleys with deep, fertile soils filled with grasslands, floodplains, woodlands, and wetlands that abounded with hippos, zebras, antelopes, and many other animals, some extinct for millennia.

In contrast to ice age environments elsewhere on Earth, it was a lush environment with a mild climate that disappeared under rising sea levels around 11,500 years ago.

An interdisciplinary, international team of scientists has now brought this pleasant cradle of humankind back to life in a special collection of articles that reconstruct the paleoecology of the Paleo-Agulhas Plain, a now-drowned landscape on the southern tip of Africa that was high and dry during glacial phases of the last 2 million years.

"These Pleistocene glacial periods would have presented a very different resource landscape for early modern human hunter-gatherers than the landscape found in modern Cape coastal lowlands, and may have been instrumental in shaping the evolution of early modern humans," said Janet Franklin, a distinguished professor of biogeography in the department of Botany and Plant Sciences at UC Riverside, an associate member of the African Centre for Coastal Palaeoscience at Nelson Mandela University in South Africa, and co-author of several of the papers.

Some of the oldest anatomically modern human bones and artifacts have been found in cliff caves along the coast of South Africa. For many years, the lack of shellfish in some layers at these sites puzzled archaeologists. In spite of apparently living near the ocean, the inhabitants hunted mostly big game -- the sort of animals that typically live farther inland.

Scientists knew a submerged landscape existed on the continental shelf just offshore, but it wasn't until recently, perhaps inspired by rising sea levels of our current human-caused global warming, they realized these caves might have made up the westernmost edge of a long-lost plain.

During most of the Pleistocene, the geological era before the one we live in now, these caves were not located on the coast. With so much of the Earth's water locked up in continent-sized glaciers, sea level was much lower, and humans could have thrived between the cliffs and a gentler coastline miles and miles to the east.

A special issue of Quaternary Science Reviews presents papers using a wide range of techniques to reconstruct the environment and ecology of the Paleo-Agulhas Plain. They reveal a verdant world rich with game, plant, and coastal resources, periodically cut off from the mainland during warm spells between glacial periods when sea level rose to levels similar to those of today, which would have played an important role in human evolution.

Franklin and her colleagues used modern vegetation patterns along the Cape south coast to develop models of the expected vegetation for the various soil types, as well as the climate (especially rainfall) and fire regimes of the past glacial periods that framed most of the timeframe in which modern humans emerged.

Joining her in the research were Richard M. Cowling and Alastair J. Potts of Nelson Mandela University; Guy F. Midgley at Stellenbosch University; Francois Engelbrecht of the University of Witwatersrand; and Curtis W. Marean of Arizona State University.

Vegetation was reconstructed based on a model of the ancient climate and fire patterns of these glacial phases that define human evolution. The group developed the vegetation model based on present-day patterns and environmental conditions, compared their model to an independently derived vegetation map to validate it, then applied it to the climate, landforms, and soils reconstructed for the peak of the last ice age on the Palaeo-Agulhas Plain.

Reconstruction, mapping, and modeling of the paleo-climate, geology, and soils by their collaborators are featured in other articles in the special issue.

The model found the paleo-landscape exposed during glacial low-sea levels added a land area the size of Ireland to the southern tip of Africa. Near the coast, it was dominated by "limestone fynbos," a low-stature, but species-rich shrubland typical of contemporary South Africa's Cape Floristic Province, a global plant diversity hotspot. The northern plains were mostly grasslands in shallow floodplains and on shale bedrock.

This savanna-like vegetation is rare in the modern landscape and would have supported the megafauna typical of glacial periods. These game animals, found in the archaeological record, include a great diversity of grazing animals, including the now-extinct giant Cape Buffalo, and others of which no longer occur naturally in this part of Africa, such as giraffes.

The Paleo-Agulhas plain had extremely high plant species diversity, as well as a greater variety of ecosystems and plant communities than currently found in this region, including shale grassland with dune fynbos-thicket mosaic on uplands and broad and shallow floodplains supporting a mosaic of woodland and grassland on fertile, alluvial soils.

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This research is published as, "Describing a drowned Pleistocene ecosystem: Last Glacial Maximum vegetation reconstruction of the Palaeo-Agulhas Plain."

About UC Riverside

The University of California, Riverside (http://www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment is more than 24,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of almost $2 billion. To learn more, email news@ucr.edu.

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How do plants forget?

An international group of researchers found the answer to the question: How do plants forget?

INSTITUTO GULBENKIAN DE CIENCIA

The study now published in Nature Cell Biology reveals more information on the capacity of plants, identified as 'epigenetic memory,' which allows recording important information to, for example, remember prolonged cold in the winter to ensure they flower at the right time during the spring.

As soon as they produce seeds, this information is "erased" from memory so they don't bloom too early the following winter.

Although they do it differently than humans, plants also have memories. This so-called "epigenetic memory" occurs by modifying specialized proteins called histones, which are important for packaging and indexing DNA in the cell. One such histone modification, called H3K27me3, tends to mark genes that are turned off. In the case of flowering, cold conditions cause H3K27me3 to accumulate at genes that control flowering. Previous work from the Berger lab has shown how H3K27me3 is faithfully transmitted from cell to cell so that in the Spring, plants will remember that it was cold and that winter is over, allowing them to flower at the right time. But just as importantly, once they've flowered and made seeds, the seeds need to forget this 'memory' of the cold so that they do not flower too soon once winter comes around again. Since H3K27me3 is faithfully copied from cell to cell, how do plants go about forgetting this memory in seeds?

Jörg Becker, principal investigator at the Instituto Gulbenkian de Ciência, involved in the international team led by researcher Frédéric Berger, of the Gregor Mendel Institute of the Austrian Academy of Sciences, says that researchers set out to analyse histones in pollen, hypothesizing that the process of forgetting would most likely occur in the embedded sperm. According to Jörg Becker, "the study led us to identify a phenomenon, the so-called "epigenetic resetting", akin to erasing and reformatting data on a hard drive".

The researchers were surprised to find that H3K27me3 completely disappeared in sperm. They found that sperm accumulate a special histone that is unable to carry H3K27me3. This ensures that this modification is erased from hundreds of genes, not only those that prevent flowering but also ones which control a large array of important functions in seeds, which are produced once the sperm is carried by the pollen to fuse with the plant egg cell.

This phenomenon is called "epigenetic resetting" and is akin to erasing and reformatting data on a hard drive.

"This actually makes a lot of sense from an ecological perspective" says Dr. Borg, first author of the paper. "Since pollen can spread over long distances, by wind or bees for example, and much of the "memory" carried by H3K27me3 is related to environmental adaptation, it makes sense that seeds should "forget" their dad's environment and instead remember their mother's, since they are most likely to spread and grow next to mom."

According to Dr. Berger "Like plants, animals also erase this epigenetic memory in sperm, but they do it by replacing histones with a completely different protein. This is one of the first examples of how a specialized histone variant can help reprogram and reset a single epigenetic mark while leaving others untouched. There are many more unstudied histone variants in both plants and animals, and we expect that aspects of this resetting mechanism we have discovered will be found in other organisms and developmental contexts."

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This work was carried out by an international team with members from the Gregor Mendel Institute in Austria, the Cold Spring Harbor Laboratory, Yale University, University of Kentucky, and Purdue University in the USA, Nagoya University in Japan, University of Edinburg in the UK, and the Instituto Gulbenkian Ciência in Portugal. Funding was provided by the Austrian Science Fund, ERA-CAPS, the Howard Hughes Medical Institute, NIH, the Japan Society for the Promotion of Science, the Wellcome Trust, and the European Research Council

Indigenous protection

Anthropologists, physicians and tribal leaders develop a strategy for managing and containing COVID-19 among an indigenous population

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

The global reach of COVID-19 is unquestionable. Every day, news reports highlight the disease's increasing toll on countries and major cities around the world.

However, little attention is paid to indigenous populations worldwide who may be especially vulnerable to COVID-19 but are largely excluded from most national or regional efforts to curb the spread of the disease. Even in high-income countries, indigenous groups like the Navajo have been hit hard by COVID-19, with per capita infection rates rivaling those of New York and New Jersey.

A team of anthropologists, physicians and tribal leaders has developed a strategy for mitigating the impact of COVID-19 among the Tsimane, an indigenous population in the Bolivian Amazon. Led by UC Santa Barbara's Michael Gurven and Hillard Kaplan of Chapman University, their multiphase plan brings together relevant stakeholders to best serve Tsmane interests. They hope to provide a general template that can be applied to other indigenous groups, and to promote a wider discussion on how to adapt strategies to local circumstances, with the goal of minimizing harm to indigenous populations due to the SARS-CoV-2 pandemic.

Their work is published in the journal The Lancet.

"In Bolivia, most attention is focused in the cities, where the pandemic first appeared. Indigenous communities have not been part of any organizational plan," said Daniel Eid Rodriguez, the paper's Bolivian co-author and a physician working with the Tsimane Health and Life History Project since 2005. "Although resources in Bolivia and other countries are too limited to create the ideal response plan, there are many people and organizations who are ready to help. Finding and building collaboration is key for the success of any COVID-19 plan."

To reach a wider audience, the authors have published their paper not only in English, but also in Spanish, Portuguese and French -- languages spoken in countries where many indigenous people reside.

"We've been working with the Tsimane and other indigenous groups in Bolivia for almost two decades," said Gurven, co-director of the Tsimane Health and Life History Project. Research operations shut down in mid-March, as did most activity worldwide, but he and his team recognized that indigenous groups living in remote areas may be especially vulnerable to COVID-19, given their limited access to up-to-date information and appropriate health care.

So building on their years of active involvement with Tsimane health care, the researchers initiated conversations with tribal authorities and other local officials. Together, they began working on a plan, first to get folks informed and prepared, and then to act once COVID-19 hit the region.

"After a teenage Yanomami boy died of COVID-19 there was, understandably, a lot of panic about the potential plight of indigenous populations around the world in light of this new, unpredictable threat," Gurven said. "Since our team had already been working with the Tsimane to try and work out a reasonable plan, we thought it would be a great opportunity to move the conversation toward a concrete blueprint that could, hopefully, be adapted to work in similar areas."

While every individual around the world is vulnerable to COVID-19 because it is new and no one has developed any immunity, many indigenous communities are at additional risk because of widespread respiratory illness, including prior history of tuberculosis, bronchitis and lower respiratory tract infections and compromised immune function.

"These could make people more at risk of having COVID-19 complications," said Gurven. According to the World Bank, over 370 million indigenous people inhabit over 90 countries, in both rural and urban areas. Though health clinics may be present in rural areas, access and resources such as medication, portable oxygen and other treatments may be very limited. In Bolivia, the local hospital will likely be overloaded by the time COVID-19 reaches Tsimane villages, and the existing remote health outposts are not yet equipped to diagnose or treat COVID-19.

The potential for higher mortality among infected individuals makes COVID-19 more salient for indigenous populations, Gurven notes, for reasons different from those typically considered. "Indigenous elders are at greater risk because of their age and comorbidity; yet they are crucial for helping to pass on long-standing traditions," Gurven explained. "They are 'walking libraries,' the ones who transmit cultural practices, native language and rituals that are crucial to indigenous identity."

While certain elements of the indigenous populations make them more vulnerable to COVID-19, other factors may foster resilience. "Many indigenous populations maintain the ability to provide their own sustenance through farming, fishing, hunting and foraging activities," said Gurven. "The ability to get food in self-sustaining ways -- both in terms of the know-how and having use rights in native territories -- makes it easier for some indigenous communities to self-isolate and reduce COVID-19 exposure that might otherwise come from visits to nearby town."

"Tribal sovereignty also allows indigenous groups to make their own decisions, especially when it comes to restricting access to their communities," Gurven went on. "Also, strong family bonds and a tradition of community meetings helps provide everyone with the latest COVID-19 information and to coordinate action -- without the kind of political polarization we've seen in the U.S. that seems to shape what people know about COVID-19 and what should be done."

The multiphase plan he and his team developed began taking shape before COVID-19 was confirmed in the Beni region of Bolivia, where the Tsimane reside. The goal of Phase I was education and preparation. "Our team of trained Tsimane visited over 60 villages for awareness campaigns, using a variety of materials such as Centers for Disease Control posters translated to the Tsimane language," Gurven said. "In meetings, each community came up with a specific plan for collective isolation and for quarantining suspected cases."

They also developed a list of material needs to help with the collective isolation of Tsimane communities to minimize reliance on markets and outside merchants. Salt, for example, is used not just to flavor food, but also to preserve meat and fish. "So we made massive deliveries of these items to each community," said Gurven.

Phase II of the plan began when COVID-19 reached the Beni in mid-April. It focuses on implementing collective isolation containment of Tsimane communities, COVID-19 containment and patient management. "Our plan is adapted to a low-tech environment of inadequate hospital facilities and to lower population density where isolation is possible for whole communities," said Kaplan, co-director of the Tsimane Health and Life History Project.

"It prioritizes protecting the elderly, rapid-testing with contact-tracing and patient monitoring with portable oxygen support for those who need it," Kaplan continued. To track the location of disease 'hotspots,' the team will take advantage of a variety of communication methods and their detailed GPS data available on resident structure and social networks.

"Details are likely to change as new ways to diagnose or treat COVID-19 become available," Gurven noted. As of now, he added, no confirmed cases have been reported in the towns closest to Tsimane communities.

The authors hope their paper will serve to affect policy and call for action. "Our article is directed toward the heads of state in countries with indigenous peoples, tribal leaders, scientists, health care workers, missionaries and non-governmental organizations that work with tribal peoples," said Kaplan. "We also hope that charitable organizations and ordinary citizens will be inspired to look for ways to help reduce the wave of death that will occur in the face of inaction."

"History teaches us that the effects of a new infectious disease on a vulnerable population can be devastating," said MemorialCare's David Michalik, a co-author of the paper and a specialist in pediatric infectious disease. "Our protocol seeks to augment already existing plans that countries may have in place, and raise awareness that even in 2020, indigenous communities are at risk of being wiped out if nothing is done."


Other co-authors include Sarah Alami and Thomas Kraft of UC Santa Barbara. Other senior co-authors include Benjamin Trumble of Arizona State University, Jonathan Stieglitz of the Institute for Advanced Study in Toulouse and Gregory Thomas of MemorialCare.

Gauging water loss from northern peatlands, a likely accelerant of climate change

MARINE BIOLOGICAL LABORATORY

IMAGE: DATA ON WATER LOSS FROM PEATLANDS TO THE ATMOSPHERE WAS COLLECTED BY EDDY COVARIANCE FLUX TOWERS IN 95 LOCATIONS ACROSS THE GLOBAL BOREAL BIOME. THIS FLUX TOWER IS LOCATED IN... 

CREDIT: MANUEL HELBIG

WOODS HOLE, Mass. -- More carbon is stored in the forests, peatlands, and lakes of the high northern (boreal) latitudes than is currently in the atmosphere. Therefore, understanding how the boreal latitudes, which include Canada and Alaska, respond to global warming is very important for predicting its trajectory. As the climate warms, the air gets drier and can take up more water. The pines, spruces, and larches of boreal forests respond by largely retaining their water, but it hasn't been known how boreal peatlands (bogs and fens) respond.

To compensate, a team of 59 international scientists, including Inke Forbrich of the Marine Biological Laboratory, pooled their data and discovered boreal peatlands lose more water than do forests in response to drying air. This has important implications not only for projections of water availability in these regions but for global carbon-climate feedbacks. With a lower water table, peatlands are more likely to release CO2 to the atmosphere, which in turn would accelerate the pace of global warming.

Most current global climate models assume the boreal region consists only of forest ecosystems. Adding peatlands data will improve their projections. Led by scientists at Canada's McMaster University, the team published their report this week iNature Climate Change.

A team of 59 international scientists, including at McMaster University and the Marine Biological Laboratory, Woods Hole, pooled their data and discovered boreal peatlands lose more water than do forests in response to drying air. This has important implications not only for projections of water availability in the boreal biome but for global carbon-climate feedbacks.

Citation:

Manuel Helbig et al (2020) Increasing contribution of peatlands to boreal evapotranspiration in a warming climate. Nature Climate Change, DOI: 10.1038/s41558-020-0763-7

McMaster University press release

The Marine Biological Laboratory (MBL) is dedicated to scientific discovery - exploring fundamental biology, understanding marine biodiversity and the environment, and informing the human condition through research and education. Founded in Woods Hole, Massachusetts in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago

Online romance scams: A modern form of fraud

This article by Dr. Andrea Pozza et al. is published in Clinical Practice & Epidemiology in Mental Health, Volume 16, 2020

BENTHAM SCIENCE PUBLISHERS

 

Over the last 20 years, the rapid development of digital communication technology has given rise to new forms of social interaction on social media. Digital communication technologies can overcome physical, social and psychological barriers in building romantic relationships. Around 1400, dating sites/chats have been created over the last decade in North America alone. Solely in the UK, 23% of Internet users have met someone online with whom they had a romantic relationship for a certain period and that even 6% of married couples met through the web.

While communication technologies have revolutionized, and continue to revolutionize, the modalities of interaction and the building of emotional attachment on the one hand, on the other, the online dating industry has given rise to new forms of pathologies and crime. Online romance scams are a modern form of fraud that have spread in Western societies along with the development of social media. Through a fictitious Internet profile, the scammer develops a romantic relationship with the victim for 6-8 months, building a deep emotional bond with the aim of extorting economic resources in a manipulative dynamic. There are two notable features: on the one hand, the double trauma of losing money and a relationship, on the other, the victim's shame upon discovery of the scam, an aspect that might lead to underestimation of the number of cases. Sixty-three percent of social media users and 3% of the general population report having been a victim at least once. Women, middle-aged people, and individuals with higher tendencies to anxiety, romantic idealization of affective relations, impulsiveness and susceptibility to relational addiction are at higher risk of being victims of the scam. Understanding the psychological characteristics of victims and scammers will allow at-risk personality profiles to be identified and prevention strategies to be developed.

This article is open access and can be obtained from the following link: https://benthamopen.com/FULLTEXT/CPEMH-16-24

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Persistent inequitable exposure to air pollution in Salt Lake County schools

Minority students experience higher concentrations of PM 2.5 levels in clean, moderate and poor air quality scenarios

UNIVERSITY OF UTAH

 

IMAGE: LOCATIONS OF THE 174 PUBLIC SCHOOLS INCLUDED IN THE STUDY AND THE PM 2.5 SENSORS. 

CREDIT: MULLEN ET. AL. ENVIRO RES (2020)

Salt Lake County, Utah's air pollution varies over the year, and at times it is the worst in the United States. The geography traps winter inversions and summertime smog throughout the Salt Lake Valley, but underserved neighborhoods--and their schools--experience the highest concentrations. Previous research has shown pollution disparities using annual averages of PM 2.5 levels, the tiny breathable particles that can damage lungs just hours after exposure. Children are especially at risk and experience more than just health effects; exposure to PM 2.5 affects school attendance and academic success.

A new study utilized a community-university partnership of nearly 200 PM 2.5 sensors through the University of Utah's Air Quality and U (AQ&U) network. U researchers explored social disparities in air pollution in greater detail than ever before, and their findings reveal persistent social inequalities in Salt Lake County. The paper posted online ahead of publication in the journal Environmental Research.

The researchers analyzed PM 2.5 levels at 174 public schools in Salt Lake County, Utah under three different scenarios: relatively clean, moderate inversion and major inversion days. Schools with predominately minority students were disproportionally exposed to worse air quality under all scenarios. Charter schools and schools serving students from low income households were disproportionally exposed when PM 2.5 was relatively good or moderate. The findings speak to the need for policies that protect school-aged children from environmental harm.

"The persistence of these injustices -- from the pretty clean, but health-harming levels all the way up to the horrific air days--at schools serving racial/ethnic minority kids is unacceptable," said Sara Grineski, U professor of sociology and environmental studies and senior author of the paper.

The authors expected social disparities on bad air days, but were surprised that they persisted on clean air days when PM 2.5 levels are still higher than recommended by the U.S. Environmental Protection Agency.

"What makes this project so novel is the community-U partnership that gave us access to this larger network of sensors and helped provide the detailed study. If we had relied on Utah Department of Air Quality, we'd only have had two monitors and would have missed the nuanced variability," said Casey Mullen, a doctoral student at the U and lead author of the study.

A higher-resolution snapshot

The worst PM2.5 episodes occur during the winter, when cold air settles into the Salt Lake Valley and high pressure weather systems act as a lid that seals in particulate matter from vehicle exhaust, wood-burning fires and emission from industrial facilities. Locals refer to these periods as inversions, which can last from a few days to a few weeks. The lowest elevations experience high concentrations of PM 2.5 for the longest time, impacting the residential communities disproportionately. The study compared the PM 2.5 levels at 174 public schools in 10-minute increments over 2-day periods during each of three events: a major winter inversion (poor air quality), a moderate winter inversion (moderate air quality) and a relatively clean, fall day (good air quality). The extensive AQ&U network made up of 190 PM 2.5 sensors is extremely sensitive-- each sensor collects PM 2.5 concentrations every second, then uploads the 60-second to a database that the public can access through the U's AQ&U website: https://aqandu.org.

The researchers broke down 174 Salt Lake County public schools with respect to race/ethnicity, economic status, and student age. They also distinguished between school type; Title I Status (schools serving majority low-income households), charter school type, and alternative or special education school type. The average student body was 31% Hispanic, 15% non-Hispanic minority, and 54% white and about 45% of the schools were Title I eligible. Just over half of the schools were primary schools, about 16% were charter schools, and about 5% were alternative or special education schools.

During relatively clean air days, racial/ethnic minority students were disproportionally exposed to high concentrations. At the school level, a 21% increase in the proportion of Hispanic 

Mean 10-min PM 2.5 levels for each 48-hour scenario at the Salt Lake County schools during a clean, moderate winter persistent air pool (PCAP, inversion) and major PCAP event. The bigger the blue dot, the higher the concentration of PM 2.5 particles. In all three scenarios, the lowest PM 2.5 concentrations were on the south and east side of the study area along the bench where elevation ascends from the valley floor.

The evolution of PM 2.5 concentrations throughout Salt Lake County during a pollution event (not included in the study). Dark purple indicates low PM 2.5 particle concentrations, blue indicates higher PM 2.5 concentrations. The west side of the county has persistently higher concentrations under all scenarios.

Voluntary collective isolation is best response to COVID-19 for indigenous populations

Chapman University-Led study shows researchers collaborating with tribal leadership and government to develop and implement a COVID-19 prevention plan

CHAPMAN UNIVERSITY

TSIMANE HEALTH AND LIFE HISTORY PROJECT TEAM WORKED TO TRANSLATE AND MODIFY THE U.S. CENTERS FOR DISEASE CONTROL INFORMATIONAL POSTERS INTO THE LOCAL TSIMANE LANGUAGE.
CREDIT: TSIMANE HEALTH AND LIFE HISTORY PROJECT TEAM

Orange, Calif. - A team of anthropologists, physicians, tribal leaders and local government authorities developed and implemented a multi-phase COVID-19 prevention and containment plan among the Tsimane, an indigenous group of forager-horticulturists in the Bolivian Amazon. The collaborative effort is led by Hillard Kaplan, Ph.D., professor of health economics and anthropology and a member of the Economic Science Institute at Chapman University.

The study, published in The Lancet, proposes that indigenous populations worldwide share characteristics that make them especially vulnerable to COVID-19, including higher rates of extreme poverty, poor healthcare access and infrastructure, and widespread respiratory infections. As of May 7, Bolivia had 2,081 confirmed COVID-19 cases and 102 deaths, largely confined to the Santa Cruz and La Paz provinces. As of now, there are no confirmed cases in the towns closest to the Tsimane communities.

The Tsimane Health and Life History Project has been working with Tsimane communities since 2002, studying health and ageing while providing primary health care and biomedical surveillance. Kaplan, co-director of the project, and his team paused research activity in mid-March to redirect their efforts towards reducing the effects of COVID-19 on the tribal populations with whom they work with.

"The disease is spreading rapidly in Bolivia as is the case in many places throughout the developing world but has not yet reached the tribal territories where we work," said Kaplan, the principal investigator of this study. "It is clear from the painful lessons we have learned in this country and in Europe, advance planning is the key to mitigating the devastating effects of the disease."

"After a teenage Yanomami boy died of COVID-19, there was, understandably, a lot of panic about the potential plight of indigenous populations around the world in light of this new, unpredictable threat," said Michael Gurven, Ph.D., professor of anthropology at UC Santa Barbara and co-director of the Tsimane Project with Kaplan. "Since our team had already been working with the Tsimane to try and work out a reasonable plan, we thought it would be a great opportunity to move the conversation toward a concrete blueprint that could, hopefully, be adapted to work in similar areas."

The researchers believe that their approach with the Tsimane can be adapted more generally to tribal and aboriginal populations throughout the world to prevent widespread mortality, and will continue to adjust their plans according to the local circumstances and future COVID-19 discoveries.

Dr. Kaplan and his team developed their COVID-19 strategy based on two guidelines. The first is that preventative measures before mass infection can greatly reduce the burden of morbidity and mortality. The second is that any effective plan must be collaborative among all stakeholders and should involve the indigenous populations in the decision process.

These tribal communities have unique sources of resilience that can be used to prevent the potentially serious effects of COVID-19. The most pertinent is the group's cultural tradition of collective decision- making, where lively two-way discussions are held during village meetings to allow community members to speak up and contribute to a collective decision. The consensus among the Tsimane is that collective isolation is the most viable strategy for minimizing COVID-19 exposure until vaccines or treatments become available. Researchers utilized these community meetings to communicate best practices in collective isolation with the villages.

The research team has a two-phase plan. Phase I -- focused on education, outreach and preparation -- occurred while the novel coronavirus was spreading quickly in Bolivia but before there were confirmed cases in the Beni region where the Tsimane live.

The research team traveled to around 60 villages to hold community meetings. The researchers sent native speakers of the Tsimane language to these meetings to inform the population about the risks of COVID-19 and promote a collective decision-making process on how best to respond to the epidemic. These meetings lead to unanimous agreement by the Tsimanes to collectively isolate the tribal territory and its constituent communities to prevent interaction with the outside world.

The researchers also worked to translate and adapt U.S. Centers for Disease Control informational posters into the Tsimane language for dissemination.

"While some Tsimane people had heard about the existence of coronavirus, most were unaware of its imminent threat, how it is transmitted, who is most vulnerable or whether there was a cure for the disease," said Kaplan.

The research team is currently in Phase II: containment, patient management and quarantine strategies. This is being accomplished through ongoing radio communications about the current rates and areas of infection, coordination of rapid testing and contact-tracing and the provisioning of personal protective equipment for local health care workers. Phase II began in mid-April when COVID- 19 was diagnosed and confirmed in the Beni region.

"Our plan is adapted to a low-tech environment of inadequate hospital facilities and to lower population density where isolation is possible for whole communities and for families and individuals within communities," said Gregory Thomas, MD, a medical director of the Long Beach MemorialCare Heart and Vascular Institute and collaborator of the study.

"The plan places greater emphasis on testing with contact-tracing and whole-family approaches to isolation. For the management and treatment of COVID-19 cases, it emphasizes patient monitoring, especially blood oxygen, and portable oxygen support for those who need it," added David Michalik, MD, pediatric infectious disease specialist at MemorialCare Miller Women's and Children's Hospital Long Beach.

###

In addition to Kaplan, the paper's senior co-authors include Michael Gurven of UC Santa Barbara; Benjamin Trumble of Arizona State University; Jonathan Stieglitz of the Institute for Advanced Study in Toulouse, France; Gregory Thomas and David Michalik of MemorialCare.

About Chapman University

Founded in 1861, Chapman University is a nationally-ranked private university located in Southern California. Chapman is categorized by the Carnegie Classification as an R2 "high research activity" institution and offers personalized education to more than 9,000 undergraduate and graduate students. The campus has produced a Rhodes Scholar, been named a top producer of Fulbright Scholars and hosts a chapter of Phi Beta Kappa, the nation's oldest and most prestigious honor society. Based in the City of Orange, Chapman also includes the Harry and Diane Rinker Health Science Campus in Irvine. In 2019, the university opened its 11th college, Fowler School of Engineering, in its newest facility, Keck Center for Science and Engineering. Learn more about Chapman University: http://www.chapman.edu.


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Researchers find the key to preserving The Scream

Photograph of The Scream (1910?) (Munch Museum, Oslo; catalogue n. Woll.M.896). Photo Credit: Irina Crina Anca Sandu and Eva Storevik Tveit, Munch Museum.

EUROPEAN SYNCHROTRON RADIATION FACILITY

Moisture is the main environmental factor that triggers the degradation of the masterpiece The Scream (1910?) by Edvard Munch, according to the finding of an international team of scientists led by the CNR (Italy), using a combination of in situ non-invasive spectroscopic methods and synchrotron X-ray techniques. After exploiting the capability of the European mobile platform MOLAB in situ and non-invasively at the Munch Museum in Oslo, the researchers came to the ESRF, the European Synchrotron (Grenoble, France), the world's brightest X-ray source, to carry out non-destructive experiments on micro-flakes originating from one of the most well-known versions of The Scream. The findings could help better preserve this masterpiece, which is seldom exhibited due to its degradation. The study is published in Science Advances.

The Scream is among the most famous paintings of the modern era. The now familiar image is interpreted as the ultimate representation of anxiety and mental anguish. There are a number of versions of The Scream, namely two paintings, two pastels, several lithographic prints and a few drawings and sketches. The two most well-known versions are the paintings that Edvard Munch created in 1893 and 1910. Each version of The Scream is unique. Munch clearly experimented to find the exact colours to represent his personal experience, mixing diverse binding media (tempera, oil and pastel) with brilliant and bold synthetic pigments to make 'screaming colours'. Unfortunately, the extensive use of these new coloured materials poses a challenge for the long-term preservation of Munch's artworks.

The version of the Scream (1910?) that belongs to the Munch Museum (Oslo, Norway) clearly exhibits signs of degradation in different areas where cadmium-sulfide-based pigments have been used: cadmium yellow brushstrokes have turned to an off-white colour in the sunset cloudy sky and in the neck area of the central figure. In the lake, a thickly applied opaque cadmium yellow paint is flaking. Throughout its existence, several elements have played a role in the deterioration of the masterpiece: the yellow pigments used, the environmental conditions and a theft in 2004, when the painting disappeared for two years.

Since the recovery of the painting after the theft, the masterpiece has rarely been shown to the public. Instead, it is preserved in a protected storage area in the Munch Museum, in Norway, under controlled conditions of lighting, temperature (about 18°C) and relative humidity (about 50%).

(from left to right). Dr. Annalisa Chieli (University of Perugia, Italy), Dr. Letizia Monico (CNR, Italy) and Dr. Gert Nuys (Univeristy of Antwerp, Belgium) during measurements of cadmium yellow micro-flakes of The Scream (1910?) at the beamline ID21 of the European Synchrotron (ESRF, Grenoble, France). Credit: ESRF.

An international collaboration, led by the CNR (Italy), with the University of Perugia (Italy), the University of Antwerp (Belgium), the Bard Graduate Center in New York City (USA), the European Synchrotron (ESRF, France), the German Electron Synchrotron (DESY, Hamburg) and the Munch Museum, has studied in detail the nature of the various cadmium-sulfide pigments used by Munch, and how these have degraded over the years.

The findings provide relevant hints about the deterioration mechanism of cadmium-sulfide-based paints, with significant implication for the preventive conservation of The Scream.

"The synchrotron micro-analyses allowed us to pinpoint the main reason that made the painting decline, which is moisture. We also found that the impact of light in the paint is minor. I am very pleased that our study could contribute to preserve this famous masterpiece", explains Letizia Monico, one of the corresponding authors of the study.

Hitting the right formula for preservation

Monico and her colleagues studied selected cadmium-sulfide-based areas of The Scream (1910?), as well as a corresponding micro-sample, using a series of non-invasive in-situ spectroscopic analyses with portable equipment of the European MOLAB platform in combination with the techniques of micro X-ray diffraction, X-ray micro fluorescence and micro X-ray absorption near edge structure spectroscopy mainly at the ESRF, the European Synchrotron, in France, the world's most powerful synchrotron. The study of the painting was integrated with investigations of artificially aged mock-ups. The latter were prepared using a historical cadmium yellow pigment powder and a cadmium yellow oil paint tube that belonged to Munch. Both mock-ups had a similar composition to the lake in the painting. "Our goal was to compare the data from all these different pigments, in order to extrapolate the causes that can lead to deterioration", says Monico.

The study shows that the original cadmium sulfide turns into cadmium sulfate in the presence of chloride-compounds in high-moisture conditions (relative humidity, or RH ?95%). This happens even if there is no light.

"The right formula to preserve and display the main version of The Scream on a permanent basis should include the mitigation of the degradation of the cadmium yellow pigment by minimising the exposure of the painting to excessively high moisture levels (trying to reach 45% RH or lower), while keeping the lighting at standard values foreseen for lightfast painting materials. The results of this study provide new knowledge, which may lead to practical adjustments to the Museum's conservation strategy", explains Irina C. A. Sandu, conservation scientist at the Munch Museum.

"Today the Munch Museum stores and exhibits Edvard Munch's artworks at a relative humidity of about 50% and at a temperature of around 20 °C. These environmental conditions will also apply to the new Munch Museum to be opened in Spring 2020. That said, the Museum will now look into how this study may affect the current regime. Part of such a review will be to consider how other materials in the collection will respond to possible adjustments", adds Eva Storevik Tveit, paintings conservator at the Munch Museum.

Cadmium-sulfide-based yellows are not only present in Munch's artwork but also in the work of other artists contemporary to him, such as Henri Matisse, Vincent van Gogh and James Ensor.

View of the ESRF, the European Synchrotron, Grenoble, France.

"The integration of non-invasive in-situ investigations at the macro-scale level with synchrotron micro-analyses proved its worth in helping us to understand complex alteration processes. It can be profitably exploited for interrogating masterpieces that could suffer from the same weakness", reports Costanza Miliani, coordinator of the mobile platform MOLAB (operating in Europe under the IPERION CH project) and second corresponding author of this study.

Monico and colleagues, especially Koen Janssens (University of Antwerp), have a long-standing collaboration with the ESRF, the European Synchrotron, and in particular with the scientist Marine Cotte, to investigate these pigments and the best way to preserve the original masterpieces.

"At the ESRF, ID21 is one of the very few beamlines in the world where we can perform imaging X-ray absorption and fluorescence spectroscopy analysis of the entire sample, at low energy and with sub-micrometer spatial resolution", explains Janssens.

"EBS, the new Extremely Brilliant Source, the first-of-a-kind high-energy synchrotron, which is under commissioning at the moment at the ESRF, will further improve the capabilities of our instruments for the benefit of world heritage science. We will be able to perform microanalyses with increased sensitivity, and a greater level of detail. Considering the complexity of these artistic materials, such instrumental developments will highly benefit the analysis of our cultural heritage", adds Cotte, ESRF scientist and CNRS researcher director.

"This kind of work shows that art and science are intrinsically linked and that science can help preserve pieces of art so that the world can continue admiring them for years to come", concludes Miliani, coordinator of MOLAB.

Big data and synthetic chemistry could fight climate change and pollution

University of South Carolina chemists look to the future of materials design

UNIVERSITY OF SOUTH CAROLINA

IMAGE: LAURA MURDOCK, A UNIVERSITY OF SOUTH CAROLINA PHD CANDIDATE IN CHEMISTRY, EXAMINES A POLYMER FILM THAT OUTPERFORMED ALL OTHER KNOWN MEMBRANES USED FOR SEPARATING CARBON DIOXIDE AND METHANE. SHE CREATED... view more 

CREDIT: UNIVERSITY OF SOUTH CAROLINA

COLUMBIA, S.C. -- May 15, 2020 -- Scientists at the University of South Carolina and Columbia University have developed a faster way to design and make gas-filtering membranes that could cut greenhouse gas emissions and reduce pollution.

Their new method, published today in Science Advances, mixes machine learning with synthetic chemistry to design and develop new gas-separation membranes more quickly. Recent experiments applying this approach resulted in new materials that separate gases better than any other known filtering membranes.

The discovery could revolutionize the way new materials are designed and created, Brian Benicewicz, the University of South Carolina SmartState chemistry professor, said.

"It removes the guesswork and the old trial-and-error work, which is very ineffective," Benicewicz said. "You don't have to make hundreds of different materials and test them. Now you're letting the machine learn. It can narrow your search."

Plastic films or membranes are often used to filter gases. Benicewicz explained that these membranes suffer from a tradeoff between selectivity and permeability ? a material that lets one gas through is unlikely to stop a molecule of another gas. "We're talking about some really small molecules," Benicewicz said. "The size difference is almost imperceptible. If you want a lot of permeability, you're not going to get a lot of selectivity."

Benicewicz and his collaborators at Columbia University wanted to see if big data could design a more effective membrane.

The team at Columbia University created a machine learning algorithm that analyzed the chemical structure and effectiveness of existing membranes used for separating carbon dioxide from methane. Once the algorithm could accurately predict the effectiveness of a given membrane, they turned the question around: What chemical structure would make the ideal gas separation membrane?

Sanat K. Kumar, the Bykhovsky Professor of Chemical Engineering at Columbia, compared it to Netflix's method for recommending movies. By examining what a viewer has watched and liked before, Netflix determines features that the viewer enjoys and then finds videos to recommend. His algorithm analyzed the chemical structures of existing membranes and determined which structures would be more effective.

The computer produced a list of 100 hypothetical materials that might surpass current limits. Benicewicz, who leads a synthetic chemistry research group, identified two of the proposed structures that could plausibly be made. Laura Murdock, a UofSC PhD student in chemistry, made the prescribed polymers and cast them into thin films.

When the membranes were tested, their effectiveness was close to the computer's prediction and well above presumed limits.

"Their performance was very good ? much better than what had been previously made," Murdock said. "And it was pretty easy. It has the potential for commercial use."

Separating carbon dioxide and methane has an immediate application in the natural gas industry; CO2 must be removed from natural gas to prevent corrosion in pipelines. But Murdock said the method of using big data to remove the guesswork from the process leads to another question: "What other polymer materials can we apply machine learning to and create better materials for all kinds of applications?"

Benicewicz said machine learning could help scientists design new membranes for separating greenhouse gases from coal, which can help to reduce climate change.

"This work thus points to a new way of materials design," Kumar said. "Rather than test all the materials that exist for a particular application, you look for the part of a material that best serves the need that you have. When you combine the very best materials then you have a shot at designing a better material."

Laura Murdock, a PhD candidate at the University of South Carolina, shows a polymer film she made according to a chemical design prescribed by machine learning. The film outperformed all known membranes used for separating carbon dioxide and methane, demonstrating that machine learning can help chemists more quickly develop new materials.

About the Study

The study is titled: "Designing exceptional gas-separation polymer membranes using machine learning."

The authors are: J. Wesley Barnett, Connor R. Bilchak, Yiwen Wang and Sanat K. Kumar from the Columbia University Department of Chemical Engineering; Brian C. Benicewicz and Laura A. Murdock from the University of South Carolina Department of Chemistry and Biochemistry; and Tristan Bereau from the Max Planck Institute for Polymer Research.

The study was supported by the National Science Foundation Graduate Research Fellowship Program (grant DGE-16-44869 to C.R.B.), the Designing Materials to Revolutionize and Engineer our Future Program (grant 1629502 to C.R.B., J.W.B., and S.K.K. and grant 1629052 to B.C.B. and L.A.M.), and the Emmy Noether Program of the Deutsche Forschungsgemeinschaft (to T.B.). S.K.K., J.W.B., and C.R.B. acknowledge that the majority of the work was funded by NSF through DMREF grant CTS-1629502. This project was started under a previous NSF grant (DMR150730), which was continued as grant DMR-1929655.

The authors declare no financial or other conflicts of interest.