DEEPWATER HORIZON

Oil in the ocean photooxides within hours to days, new study finds

Study provides new details on the fate of spilled oil in the marine environment, effectiveness of chemical dispersants

UNIVERSITY OF MIAMI ROSENSTIEL SCHOOL OF MARINE & ATMOSPHERIC SCIENCE

Research News

 

IMAGE: SATELLITE IMAGE TAKEN ON MAY 9, 2010 OF THE DEEPWATER HORIZON OIL SPILL SITE IN THE GULF OF MEXICO. view more 

CREDIT: MODIS ON NASA'S AQUA SATELLITE, 9 MAY 2010 @ 190848 UTC. DOWNLINK AND PROCESSED AT THE UM ROSENSTIEL SCHOOL'S CENTER FOR SOUTHEASTERN TROPICAL ADVANCED REMOTE SENSING (CSTARS)

MIAMI--A new study lead by scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science demonstrates that under realistic environmental conditions oil drifting in the ocean after the DWH oil spill photooxidized into persistent compounds within hours to days, instead over long periods of time as was thought during the 2010 Deepwater Horizon oil spill. This is the first model results to support the new paradigm of photooxidation that emerged from laboratory research.

After an oil spill, oil droplets on the ocean surface can be transformed by a weathering process known as photooxidation, which results in the degradation of crude oil from exposure to light and oxygen into new by-products over time. Tar, a by-product of this weathering process, can remain in coastal areas for decades after a spill. Despite the significant consequences of this weathering pathway, photooxidation was not taken into account in oil spill models or the oil budget calculations during the Deepwater Horizon spill.

The UM Rosenstiel School research team developed the first oil-spill model algorithm that tracks the dose of solar radiation oil droplets receive as they rise from the deep sea and are transported at the ocean surface. The authors found that the weathering of oil droplets by solar light occurred within hours to days, and that roughly 75 percent of the photooxidation during the Deepwater Horizon oil spill occurred on the same areas where chemical dispersants were sprayed from aircraft. Photooxidized oil is known to reduce the effectiveness of aerial dispersants.

"Understanding the timing and location of this weathering process is highly consequential. said Claire Paris, a UM Rosenstiel School faculty and senior author of the study. "It helps directing efforts and resources on fresh oil while avoiding stressing the environment with chemical dispersants on oil that cannot be dispersed."

"Photooxidized compounds like tar persist longer in the environment, so modeling the likelihood of photooxidation is critically important not only for guiding first response decisions during an oil spill and restoration efforts afterwards, but it also needs to be taken into account on risk assessments before exploration activities" added Ana Carolina Vaz, assistant scientist at UM's Cooperative Institute for Marine and Atmospheric Studies and lead author of the study.

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The study, titled "A Coupled Lagrangian-Earth System Model for Predicting Oil Photooxidation," was published online on Feb 19, 2021 in the journal Frontiers in Marine Science. The authors of the paper include: Ana Carolina Vaz, Claire Beatrix Paris and Robin Faillettaz.

The study was supported by the Gulf of Mexico Research Initiative (GoMRI): C-IMAGE III (Center for the Integrated Modeling and Analysis of the Gulf Ecosystem) and RECOVER 2 (Relationship of Effects of Cardiac Outcomes in ?sh for Validation of Ecological Risk).

New machine learning model could remove bias from social network connections

PENN STATE

Research News

 

UNIVERSITY PARK, Pa. -- Did you ever wonder how social networking applications like Facebook and LinkedIn make recommendations on the people you should friend or pages you should follow?

Behind the scenes are machine learning models that classify nodes based on the data they contain about users -- for example, their level of education, location or political affiliation. The models then use these classifications to recommend people and pages to each user. But there is significant bias in the recommendations made by these models -- known as graph neural networks (GNNs) -- as they rely on user features that are highly related to sensitive attributes such as gender or skin color.

Recognizing that the majority of users are reluctant to publicize their sensitive attributes, researchers at the Penn State College of Information Sciences and Technology have developed a novel framework which estimates sensitive attributes to help GNNs make fair recommendations.

The team found that their model, called FairGNN, maintains high performance on node classification using limited, user-supplied sensitive information, while at the same time reducing bias.

"It has been widely reported that people tend to build relationships with those sharing the same sensitive attributes such as ages and regions," said Enyan Dai, doctoral candidate in informatics and lead author on the research paper. "There are some existing machine learning models that aim to eliminate bias, but they require people's sensitive attributes to make them fair and accurate. We are proposing to apply another model based on the very few sensitive attributes that we have (and instead look at other provided information) which could provide us very good insight to give fair predictions toward sensitive attributes such as your gender and skin color."

The researchers trained their model with two real-world datasets: user profiles on Pokec, a popular social network in Slovakia, similar to Facebook and Twitter; and a dataset of approximately 400 NBA basketball players. In the Pokec dataset, they treated the region in which each user was from as the sensitive attribute, and set the classification task to predict the working field of the users. In the NBA data, they identified players as those in the U.S. and those overseas, using location as the sensitive attribute with the classification task to predict whether the salary of each player is over the median.

They then used the same datasets to test their model with other state-of-the-art methods for fair classification. First, they evaluated FairGNN in terms of fairness and classification performance. Then, they performed "ablation studies" -- which remove certain components of the model to test the significance of each component to the overall system -- to further strengthen the model. They then tested whether FairGNN is effective when different amounts of sensitive attributes are provided in the training set.

"Our experiment shows that the classification performance doesn't decrease," said Suhang Wang, assistant professor of information sciences and technology and principal investigator on the project. "But in terms of fairness, we can make the model much more fair."

According to the researchers, their framework could make an impact for other real-world use cases.

"Our findings could be useful in applications, such as job applicant rankings, crime detection or in financial loan applications," said Wang. "But those are domains where we don't want to introduce bias. So we want to give accurate predictions while maintaining fairness."

Added Dai, "[If] this fair machine learning model could be introduced in these applications, we will have more fair data and this problem would be gradually dissolved."

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Dai and Wang presented their work this week at the virtual ACM International Conference on Web Search and Data Mining, with support from the National Science Foundation and the Global Research Outreach program of Samsung Advanced Institute of Technology.

 

Financial strain predicts future risk of homelessness and partly explains the effect of mental illness

WOLTERS KLUWER HEALTH

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IMAGE: TO WHAT EXTENT DOES FINANCIAL STRAIN MEDIATE THE RELATIONSHIP BETWEEN SEVERE MENTAL ILLNESS AND HOMELESSNESS? view more 

CREDIT: ELBOGEN ET AL. (2021) | MEDICAL CARE | DOI: 10.1097/MLR.0000000000001453

March 12, 2021 - Financial strains like debt or unemployment are significant risk factors for becoming homeless, and even help to explain increased risk of homelessness associated with severe mental illness, reports a study in a supplement to the April issue of Medical Care. The journal is published in the Lippincott portfolio by Wolters Kluwer.

The findings "suggest that adding financial well-being as a focus of homelessness prevention efforts seems promising, both at the individual and community level," according to the new research, led by Eric Elbogen, PhD, of the US Department of Veterans Affairs (VA) National Center on Homelessness and Duke University School of Medicine. The study appears as part of a special issue on "Multimorbidity and social drivers of homelessness and health," produced in partnership between the VA National Center on Homelessness and the American Public Health Association Caucus on Homelessness.

Financial strain is a mediator of the link between homelessness and mental illness

Using data on nearly 35,000 participants in a nationally representative longitudinal survey, Dr. Elbogen and colleagues analyzed financial strain as a predictor of homelessness, on its own and in combination with mental illness. Responses to a 2001-02 survey were analyzed to identify factors associated with homelessness at a follow-up survey in 2004-05.

All types of financial strain analyzed - financial crises and debt, lower income, and unemployment - were associated with an increased risk of future homelessness. As expected, severe mental illness - psychotic, bipolar, or depressive disorder - was directly related to an increased risk of homelessness.

In addition, there was a significant "mediating effect" of financial strain, which explained 39 percent of the link between homelessness and mental illness. Homelessness risk was lowest for participants with none of the four types of financial strain, whether or not they had severe mental illness.

"Conversely, participants with all four financial strain variables had significantly higher risk of homelessness," Dr. Elbogen and coauthors write. The risk of becoming homeless increased with each additional type of financial strain, independent of mental illness.

The findings offer a "fresh perspective" on homelessness prevention efforts, the researchers write. "[I]nterventions could be proactively targeted at improving an individual's financial literacy and well-being such that they could prevent situations that may contribute to future homelessness."

The finding that financial strain accounts for part of the impact of severe mental illness "suggests that addressing mental illness without consideration of financial strain may not lead to optimal reduction in homelessness risk," Dr. Elbogen and colleagues add. The study supports efforts to help homeless individuals grow financially through employment, increased financial knowledge, and money management skills - as offered in effective interventions such as Housing First and VA homeless programs.

The special supplement to Medical Care focuses "on the intersection of homelessness, medical illnesses, and related social factors," according to an introductory guest editorial by Jack Tsai, PhD, of the VA National Center on Homelessness and University of Texas Health Science Center at Houston and colleagues. A key focus is on the rising rates of multimorbidity - having multiple medical, mental health, and substance use disorders - amid the ongoing obesity crisis in an aging population.

The supplement includes nine original papers examining special populations such as homeless youth, older adults, and veterans, along with medical and behavioral health conditions such as tuberculosis, HIV, and opioid use disorder. It also presents two editorials commenting on the history of homelessness and its association with suicide. Dr. Tsai and colleagues write: "This special issue illustrates the complex realities of homelessness but also the progress that has been made and the continued efforts and gaps in knowledge that need work."

Click here to read "Financial Strain, Mental Illness, and Homelessness: Results from a National Longitudinal Study."

DOI: 10.1097/MLR.0000000000001453

About Medical Care

Rated as one of the top ten journals in health care administration, Medical Care is devoted to all aspects of the administration and delivery of health care. This scholarly journal publishes original, peer-reviewed papers documenting the most current developments in the rapidly changing field of health care. Medical Care provides timely reports on the findings of original investigations into issues related to the research, planning, organization, financing, provision, and evaluation of health services. In addition, numerous special supplementary issues that focus on specialized topics are produced with each volume. Medical Care is the official journal of the Medical Care Section of the American Public Health Association.

About Wolters Kluwer

Wolters Kluwer (WKL) is a global leader in professional information, software solutions, and services for the clinicians, nurses, accountants, lawyers, and tax, finance, audit, risk, compliance, and regulatory sectors. We help our customers make critical decisions every day by providing expert solutions that combine deep domain knowledge with advanced technology and services.

Wolters Kluwer reported 2019 annual revenues of €4.6 billion. The group serves customers in over 180 countries, maintains operations in over 40 countries, and employs approximately 19,000 people worldwide. The company is headquartered in Alphen aan den Rijn, the Netherlands.

Wolters Kluwer provides trusted clinical technology and evidence-based solutions that engage clinicians, patients, researchers and students with advanced clinical decision support, learning and research and clinical intelligence. For more information about our solutions, visit https://www.wolterskluwer.com/en/health and follow us on LinkedIn and Twitter @WKHealth.

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 AND HUMANS INFECTED MINKS

SARS-CoV-2 jumped from bats to humans without much change

PLOS

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IMAGE: SCHEMATIC OF OUR PROPOSED EVOLUTIONARY HISTORY OF THE NCOV CLADE AND PUTATIVE EVENTS LEADING TO THE EMERGENCE OF SARS-COV-2. view more 

CREDIT: MACLEAN OA, ET AL. (2021), NATURAL SELECTION IN THE EVOLUTION OF SARS-COV-2 IN BATS CREATED A GENERALIST VIRUS AND HIGHLY CAPABLE HUMAN PATHOGEN. PLOS BIOL 19(3): E3001115. CC-BY...

How much did SARS-CoV-2 need to change in order to adapt to its new human host? In a research article published in the open access journal PLOS Biology Oscar MacLean, Spyros Lytras at the University of Glasgow, and colleagues, show that since December 2019 and for the first 11 months of the SARS-CoV-2 pandemic there has been very little 'important' genetic change observed in the hundreds of thousands of sequenced virus genomes.

The study is a collaboration between researchers in the UK, US and Belgium. The lead authors Prof David L Robertson (at the MRC-University of Glasgow Centre for Virus Research, Scotland) and Prof Sergei Pond (at the Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia) were able to turn their experience of analysing data from HIV and other viruses to SARS-CoV-2. Pond's state-of-the-art analytical framework, HyPhy, was instrumental in teasing out the signatures of evolution embedded in the virus genomes and rests on decades of theoretical knowledge on molecular evolutionary processes.

First author Dr Oscar MacLean explains, "This does not mean no changes have occurred, mutations of no evolutionary significance accumulate and 'surf' along the millions of transmission events, like they do in all viruses." Some changes can have an effect; for example, the Spike replacement D614G which has been found to enhance transmissibility and certain other tweaks of virus biology scattered over its genome. On the whole, though, 'neutral' evolutionary processes have dominated. MacLean adds, "This stasis can be attributed to the highly susceptible nature of the human population to this new pathogen, with limited pressure from population immunity, and lack of containment, leading to exponential growth making almost every virus a winner."

Pond comments, "what's been so surprising is just how transmissible SARS-CoV-2 has been from the outset. Usually viruses that jump to a new host species take some time to acquire adaptations to be as capable as SARS-CoV-2 at spreading, and most never make it past that stage, resulting in dead-end spillovers or localised outbreaks."

Studying the mutational processes of SARS-CoV-2 and related sarbecoviruses (the group of viruses SARS-CoV-2 belongs to from bats and pangolins), the authors find evidence of fairly significant change, but all before the emergence of SARS-CoV-2 in humans. This means that the 'generalist' nature of many coronaviruses and their apparent facility to jump between hosts, imbued SARS-CoV-2 with ready-made ability to infect humans and other mammals, but those properties most have probably evolved in bats prior to spillover to humans.

Joint first author and PhD student Spyros Lytras adds, "Interestingly, one of the closer bat viruses, RmYN02, has an intriguing genome structure made up of both SARS-CoV-2-like and bat-virus-like segments. Its genetic material carries both distinct composition signatures (associated with the action of host anti-viral immunity), supporting this change of evolutionary pace occurred in bats without the need for an intermediate animal species."

Robertson comments, "the reason for the 'shifting of gears' of SARS-CoV-2 in terms of its increased rate of evolution at the end of 2020, associated with more heavily mutated lineages, is because the immunological profile of the human population has changed." The virus towards the end of 2020 was increasingly coming into contact with existing host immunity as numbers of previously infected people are now high. This will select for variants that can dodge some of the host response. Coupled with the evasion of immunity in longer-term infections in chronic cases (e.g., in immunocompromised patients), these new selective pressures are increasing the number of important virus mutants.

It's important to appreciate SARS-CoV-2 still remains an acute virus, cleared by the immune response in the vast majority of infections. However, it's now moving away faster from the January 2020 variant used in all of the current vaccines to raise protective immunity. The current vaccines will continue to work against most of the circulating variants but the more time that passes, and the bigger the differential between vaccinated and not-vaccinated numbers of people, the more opportunity there will be for vaccine escape. Robertson adds, "The first race was to develop a vaccine. The race now is to get the global population vaccinated as quickly as possible."

###

Research Article

Peer reviewed; Experimental study; Animals

In your coverage please use these URLs to provide access to the freely available articles in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001115

Citation: MacLean OA, Lytras S, Weaver S, Singer JB, Boni MF, Lemey P, et al. (2021) Natural selection in the evolution of SARS-CoV-2 in bats created a generalist virus and highly capable human pathogen. PLoS Biol 19(3): e3001115. https://doi.org/10.1371/journal.pbio.3001115

Funding: DLR is funded by the Medical Research Council (MC_UU_1201412) and Wellcome Trust (220977/Z/20/Z). OAM is funded by the Wellcome Trust (206369/Z/17/Z). SLKP and SW are supported in part by the National Institutes of Health (R01 AI134384 (NIH/NIAID)) and the National Science Foundation (award 2027196). PL acknowledges funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 725422-ReservoirDOCS), the European Union's Horizon 2020 project MOOD (874850), the Wellcome Trust through project 206298/Z/17/Z (The Artic Network) and the Research Foundation -- Flanders (`Fonds voor Wetenschappelijk Onderzoek -- Vlaanderen', G066215N, G0D5117N and G0B9317N). MFB is funded by a grant from the Bill and Melinda Gates Foundation (INV-005517) and by NIH/NIAID Center of Excellence in Influenza Research and Surveillance contract (HHS N272201400007C). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests: The authors have declared that no competing in

An unusual creature is coming out of winter's slumber. Here's why scientists are excited.

Duke Lemur Center recreates the seasonal swings of native habitat, helping to unlock the secrets of hibernation.

DUKE UNIVERSITY

Research News

 

IMAGE: RESEARCHERS AT THE DUKE LEMUR CENTER HAVE BEEN CHANGING UP THEIR CARE TO MORE CLOSELY MATCH THE SEASONAL FLUCTUATIONS THEY EXPERIENCE IN THE WILD. view more 

CREDIT: PHOTO BY DAVID HARING, DUKE LEMUR CENTER

DURHAM, N.C. -- If you binged on high-calorie snacks and then spent the winter crashed on the couch in a months-long food coma, you'd likely wake up worse for wear. Unless you happen to be a fat-tailed dwarf lemur.

This squirrel-sized primate lives in the forests of Madagascar, where it spends up to seven months each year mostly motionless and chilling, using the minimum energy necessary to withstand the winter. While zonked, it lives off of fat stored in its tail.

Animals that hibernate in the wild rarely do so in zoos and sanctuaries, with their climate controls and year-round access to food. But now our closest hibernating relative has gone into true, deep hibernation in captivity for the first time at the Duke Lemur Center.

"They did not disappoint," said research scientist Marina Blanco, who led the project. "Indeed, our dwarf lemurs hibernated just like their wild kin do in western Madagascar."

The researchers say recreating some of the seasonal fluctuations of the lemurs' native habitat might be good for the well-being of a species hardwired for hibernation, and also may yield insights into metabolic disorders in humans.

"Hibernation is literally in their DNA," Blanco said.

Blanco has studied dwarf lemurs for 15 years in Madagascar, fitting them with tracking collars to locate them when they are hibernating in their tree holes or underground burrows. But what she and others observed in the wild didn't square with how the animals behaved when cared for in captivity.

Captive dwarf lemurs are fed extra during the summer so they can bulk up like they do in the wild, and then they'll hunker down and let their heart rate and temperature drop for short bouts -- a physiological condition known as torpor. But they rarely stay in this suspended state for longer than 24 hours. Which got Blanco to wondering: After years in captivity, do dwarf lemurs still have what it takes to survive seasonal swings like their wild counterparts do? And what can these animals teach us about how to safely put the human body on pause too, slowing the body's processes long enough for, say, life-saving surgery or even space travel?

To find out, Duke Lemur Center staff teamed up to build fake tree hollows out of wooden boxes and placed them in the dwarf lemurs' indoor enclosures, as a haven for them to wait out the winter. To mimic the seasonal changes the lemurs experience over the course of the year in Madagascar, the team also gradually adjusted the lights from 12 hours a day to a more "winter-like" 9.5 hours, and lowered the thermostat from 77 degrees Fahrenheit to the low 50s.

The animals were offered food if they were awake and active, and weighed every two weeks, but otherwise they were left to lie.

It worked. In the March 11 issue of the journal Scientific Reports, the researchers show for the first time that fat-tailed dwarf lemurs can hibernate quite well in captivity.

For four months, the eight lemurs in the study spent some 70% of their time in metabolic slow-motion: curled up, cool to the touch, barely moving or breathing for up to 11 days at a stretch, showing little interest in food -- akin to their wild counterparts.

Now that spring is afoot in North Carolina and the temperatures are warming, the lemurs are waking up. Their first physical exams after they emerged showed them to be 22% to 35% lighter than they were at the start but otherwise healthy. Their heart rates are back up from just eight beats per minute to about 200, and their appetites have returned.

"We've been able to replicate their wild conditions well enough to get them to replicate their natural patterns," said Erin Ehmke, who directs research at the center.

Females were the hibernation champs, out-stuporing the males and maintaining more of their winter weight. They need what's left of their fat stores for the months of pregnancy and lactation that typically follow after they wake up, Blanco said.

Study co-author Lydia Greene says the next step is to use non-invasive research techniques such as metabolite analysis and sensors in their enclosures to better understand what dwarf lemurs do to prepare their bodies and eventually bounce back from months of standby mode -- work that could lead to new treatments for heart attacks, strokes, and other life-threatening conditions in humans.

Blanco suspects the impressive energy-saving capabilities of these lemurs may also relate to another trait they possess: longevity. The oldest dwarf lemur on record, Jonas, died at the Duke Lemur Center at the age of 29. The fact that dwarf lemurs live longer than non-hibernating species their size suggests that something intrinsic to their biological machinery may protect against aging.

"But until now, if you wanted to study hibernation in these primates, you needed to go to Madagascar to find them in the act," Blanco said. "Now we can study hibernation here and do more close monitoring."

###

This research was supported by the Duke Lemur Center.

CITATION: "On the Modulation and Maintenance of Hibernation in Captive Dwarf Lemurs," Marina B. Blanco, Lydia K. Greene, Robert Schopler, Cathy V. Williams, Danielle Lynch, Jenna Browning, Kay Welser, Melanie Simmons, Peter H. Klopfer, Erin E. Ehmke. Scientific Reports, March 11, 2021. DOI: 10.1038/s41598-021-84727-3.

AND ONCE THE FAT TAILED DWARF LEMUR WAKES UP THEY ARE WOKE!

Farm-level study shows rising temperatures hurt rice yields

NORTH CAROLINA STATE UNIVERSITY

Research News

 

A study of the relationship between temperature and yields of various rice varieties, based on 50 years of weather and rice-yield data from farms in the Philippines, suggests that warming temperatures negatively affect rice yields.

Recent varieties of rice, bred for environmental stresses like heat, showed better yields than both traditional rice varieties and modern varieties of rice that were not specifically bred to withstand warmer temperatures. But the study found that warming adversely affected crop yields even for those varieties best suited to the heat. Overall, the advantage of varieties bred to withstand increased heat was too small to be statistically significant.

One of the top 10 countries globally in rice production, the Philippines is also a top-10 rice importer, as domestic supply cannot meet demand.

Roderick Rejesus, a professor and extension specialist of agricultural and resource economics at North Carolina State University and the corresponding author of a paper that describes the study, says that teasing out the effects of temperature on rice yields is important to understand whether rice-breeding efforts have helped address the environmental challenges faced by modern society, such as global warming.

The study examined rice yields and atmospheric conditions from 1966 to 2016 in Central Luzon, the major rice-growing region of the Philippines. Rejesus and study colleagues were able to utilize farm-level data of rice yields and area weather conditions in four-to-five-year increments over the 50-year period, a rare data trove that allowed the researchers to painstakingly examine the relationship between rice yield and temperature in actual farm environments.

"This rich data set allowed us to see what was actually happening at the farm level, rather than only observing behavior at higher levels of aggregation like in provinces or districts," Rejesus said.

The study examined three general rice varieties planted during those 50 years: traditional rice varieties; "early modern varieties" planted after the onset of the Green Revolution, which were bred for higher yields; and "recent modern varieties" bred for particular characteristics, like heat or pest resistance, for example.

Perhaps as expected, the study showed that, in the presence of warming, recent modern varieties had the best yields when compared with the early modern and traditional varieties, and that early modern varieties outperformed traditional varieties. Interestingly, some of the early modern varieties may have also mitigated heat challenges given their smaller "semi-dwarf" plant architecture, even though they were not bred to specifically resist heat.

"Taken all together, there are two main implications here," Rejesus said. "The first is that, at the farm level, there appears to be a 'yield gap' between how rice performs in breeding trials and on farms, with farm performance of recent varieties bred to be more tolerant to environmental stresses not being statistically different relative to the older varieties.

"The second is that rice breeding efforts may not have reached their full potential such that it may be possible to produce new varieties that will statistically perform better than older varieties in a farm setting."

Rejesus also acknowledged that the study's modest sample size may have contributed to the inability to find statistical significance in the differences in warming impacts between rice varietal yields.

"This paper has implications for other rice-breeding countries, like Vietnam, because the timing of the release of various rice varieties is somewhat similar to that of the Philippines," Rejesus said. "Plant-breeding institutions can learn from this type of analysis, too. It provides guidance as to where research funding may be allocated by policymakers to further improve the high temperature tolerance of rice varieties available to farmers."

Rejesus plans to further study other agricultural practices and innovations that affect crop yields, including an examination of cover crops, or plants grown on cropland in the off season that aim to keep soils healthy, to gauge whether they can mitigate the adverse impacts of a changing climate.

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The paper appears in the American Journal of Agricultural Economics. Former NC State Ph.D. student Ruixue Wang is the paper's first author. Jesse B. Tack from Kansas State University, Joseph V. Balagtas of Purdue University and Andy D. Nelson of the University of Twente are other paper co-authors. Support for the work was provided in part by the U.S. Department of Agriculture's NIFA Hatch Project No. NC02696.

- kulikowski -

Note to editors: An abstract of the paper follows.

Quantifying the Yield Sensitivity of Modern Rice Varieties to Warming Temperatures: Evidence from the Philippines

Authors: Ruixue Wang and Roderick Rejesus, North Carolina State University; Jesse B. Tack, Kansas State University; Joseph V. Balagtas, Purdue University; and Andy D. Nelson, University of Twente

Published: March 4, 2021 in American Journal of Agricultural Economics

DOI: 10.1111/ajae.12210

Abstract: This study examines the relationship between yields of modern rice varieties and warming temperatures. Data from a long-running farm-level survey in the Philippines, with rich information on planted rice varieties, allow us to estimate fixed effect econometric models of rice yields. We find that increases in temperature, especially minimum temperatures, have statistically significant negative impacts on rice yields. Point estimates of the marginal effect of higher temperatures on rice yields indicate that early modern varieties bred primarily for higher yields, pest resistance, and/or grain quality traits (i.e., not necessarily abiotic stress tolerance) tend to be more resilient to heat events than traditional rice varieties. Moreover, the marginal effect point estimates also suggest that more recent rice varieties bred for better tolerance to abiotic stresses are likely more resilient to warming than both traditional varieties and early modern varieties. Notwithstanding the heat resilience pattern suggested by these point estimates, we are unable to find statistically significant differences in the marginal yield response to warming across these three rice varietal groups. These results provide suggestive evidence that rice breeding efforts have improved resilience to warming temperatures and point to several interesting future research directions.

WAGES FOR HOUSEWORK

School closures 'sideline' working mothers

In states where elementary schools primarily offered remote instruction, the gender gap between parents in workforce surpassed 23 percentage points in 2020

"Now, more than ever, it is crucial that federal and state governments invest in expanding the public care infrastructure for children of all ages."

WASHINGTON UNIVERSITY IN ST. LOUIS

Research News

 

Decades of feminist gains in the workforce have been undermined by the COVID-19 pandemic, which has upended public education across the United States, a critical infrastructure of care that parents -- especially mothers -- depend on to work, according to new research from Washington University in St. Louis.

The research, published in Gender & Society, draws on new data from the Elementary School Operating Status (ESOS) database to show that the gender gap between mothers and fathers in the labor force has grown significantly since the onset of the pandemic in states where schools primarily offered remote instruction.

And if these circumstances continue, it could deliver a long-lasting blow to mothers' lifetime earnings and occupational trajectories.

At the start of the 2019-20 school year, U.S. mothers' rate of labor participation was, on average, 18 percentage points less than fathers'. By last September, the gap grew to over 23 percentage points in states where schools primarily offered remote instruction. In comparison, in states where in-person instruction was most common, the gender gap in parents' labor force participation grew by less than 1 percentage point, to 18.4%.

"Our research shows schools are a vital source of care for young children, and without full-time, in-person instruction, mothers have been sidelined from the labor force," said Caitlyn Collins, assistant professor of sociology in Arts & Sciences and co-author of the study.

"The longer these conditions remain in place, the more difficult it may be for mothers to fully recover from prolonged spells of non-employment, resulting in reduced occupational opportunities and lifetime earnings."

As the pandemic continues into the spring, states with significantly curtailed in-person learning will likely continue to see low maternal labor force participation with the potential for devastating, long-term employment effects for many women with children, Collins added.

How do school reopening plans impact working parents?

While the primary function of schools is children's education, they also provide an expansive infrastructure of care -- especially for elementary school-age children -- that parents, businesses and the economy rely upon, Collins said. COVID-19 has strained that infrastructure in unprecedented ways.

States have varied considerably in their approaches to slow the virus' spread and reopen schools, resulting in a patchwork structure of K-12 education across the United States.

Collins and co-authors -- Liana Christin Landivar at the Maryland Population Research Center; Leah Ruppanner at the University of Melbourne; and William Scarborough at the University of North Texas -- wanted to understand the nature and magnitude of school closures across states.

They used the ESOS database to measure the percentage of school districts offering in-person, remote and hybrid instruction models for elementary schools by state in September 2020. Then, they linked the data to the Current Population Survey to evaluate the association between school reopenings and parents' labor force participation rates, comparing such 2020 rates with those observed pre-pandemic in 2019.

In the paper, the authors describe results from the 26 states currently available in ESOS, and highlight three states as illustrative examples of the consequences of various reopening statuses.

Their findings illustrate the critical role schools play not only in supporting children's well-being, but also enabling parents, especially mothers, to maintain employment. Absent fathers' equal participation at home, mothers bear the brunt of responsibility for childrearing, both before and during the pandemic, according to Collins.

Maryland - where schools across the state primarily opened remotely in 2020 - experienced the largest drop in mothers' labor force participation. In 2019, Maryland mothers with elementary-age children had a 90% predicted probability of being in the labor force. When schools opened in 2020, that probability dropped to 74%, representing a 16-point drop. In comparison, Maryland fathers' predicted probability of labor force participation dropped by 5 percentage points, from 92% to 87% - a statistically insignificant change, the authors wrote.

Just 200 miles away, New York took a different approach: Nearly half of the elementary schools in the state offered hybrid programs consisting of a mix of remote and in-person education. Researchers found that mothers' labor force participation in New York declined by 7 percentage points, from 79% to 72%. Fathers' labor force participation dropped by 4 percentage points, from 96% to 92%. Neither of these drops was statistically significant.

Finally, in Texas - where more than half of school districts offered full-time, in-person education for elementary students - mothers' labor force participation dropped by 10 percentage points, from 77% to 67%, and fathers' from 96% to 93%. While this was a larger shift than observed in New York, it was still substantially smaller than the changes observed in Maryland.

Across all states, mothers' work attachment fell to a greater extent than fathers', but the gap is widest in states, like Maryland, where schooling was fully remote at the start of the school year.

Upon completion in spring 2021, the ESOS database will be made publicly available via the Open Science Framework, offering the reopening status of all elementary school districts in the country serving more than 500 students, or approximately 9,000 school districts.

'Something had to give'

One in three U.S. women who left employment since the onset of the COVID-19 pandemic cite childcare demands as a primary reason for their departure. Perhaps that's not surprising, though. Preliminary evidence suggests that gender inequality in the domestic division of labor worsened under the pandemic, Collins said.

Collins, Landivar, Ruppanner and Scarborough have been studying the impact of the pandemic on mothers' paid work since the first shutdowns in March 2020. Their early analysis found that mothers were more likely to reduce their work hours or exit the labor force altogether - even when both parents were able to telecommute. They suggest this is likely because mothers picked up a larger share of housework, childcare and homeschooling than fathers.

"Mothers have also reported greater increases in anxiety, depression and disturbed sleep compared to fathers, especially after experiencing a job loss or an increased housework or childcare load," said Ruppanner, associate professor of sociology at the University of Melbourne.

"Without more support from fathers, employers and the government, something had to give under this unsustainable pressure. What seems to be giving is mothers' employment," Collins said.

The fallout will last well beyond the pandemic When mothers are forced to choose between their families and jobs, it impacts not only their immediate financial stability, but also their psychological well-being, economic independence and lifetime occupational attainment and earnings.

As the current research illustrates, mothers have paid the price of the childcare crisis created by the COVID-19 pandemic.

"This is an injustice with long-term consequences for mothers' job prospects and economic stability," the researchers wrote.

"These are not personal problems, but deeply political issues that require policy interventions. Well-funded and evidence-based reopening plans are necessary to allow children to return to school face-to-face, and to allow parents to engage in paid work.

"Now, more than ever, it is crucial that federal and state governments invest in expanding the public care infrastructure for children of all ages."

 

Children's preventive healthcare costs dropped under ACA: BU study

BOSTON UNIVERSITY SCHOOL OF MEDICINE

Research News

 

The Affordable Care Act (ACA) dramatically increased children's preventive healthcare while reducing out-of-pocket costs, according to a new Boston University School of Public Health (BUSPH) study.

Published in JAMA Network Open, the study found that checkups with out-of-pocket costs dropped from 54.2% of visits in 2010 (the year the ACA passed) to 14.5% in 2018.

"This is a great feather in the cap of the ACA, even though there is still some work to do," says study lead author Dr. Paul Shafer, assistant professor of health law, policy & management at BUSPH.

"We found that one in seven families were still charged something for their children's well visits," he says, "and costs can be a barrier to parents keeping their kids up-to-date with preventive care."

Shafer and colleagues analyzed national health insurance claims data from 2006 through 2018 for children 0 to 17 years old.

Even before the ACA became law in 2010, the researchers saw improving trends in preventive pediatric care. The proportion of children who went to the doctor at least once per year without having a preventive checkup dropped from 39.3% in 2006 to 29.0% in 2018. The researchers also found a 60% increase in the proportion of so-called "sick" visits (for anything other than a checkup) that included one or more preventive services, such as immunizations or recommended screenings. The researchers write that this may mean pediatricians are increasingly taking advantage of any opportunity they can to provide preventive care.

"As deductibles and copays continue to rise, the promise of free preventive care has become a very popular benefit of the ACA," Shafer says. "According to our results, we are continuing to get better at delivering on that promise for children."

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About Boston University School of Public Health

Founded in 1976, Boston University School of Public Health is one of the top five ranked private schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations--especially the disadvantaged, underserved, and vulnerable--locally and globally.

Study finds cancer cells may evade chemotherapy by going dormant

WEILL CORNELL MEDICINE

Research News

 

Cancer cells can dodge chemotherapy by entering a state that bears similarity to certain kinds of senescence, a type of "active hibernation" that enables them to weather the stress induced by aggressive treatments aimed at destroying them, according to a new study by scientists at Weill Cornell Medicine. These findings have implications for developing new drug combinations that could block senescence and make chemotherapy more effective.

In a study published Jan. 26 in Cancer Discovery, a journal of the American Association for Cancer Research, the investigators reported that this biologic process could help explain why cancers so often recur after treatment. The research was done in both organoids and mouse models made from patients' samples of acute myeloid leukemia (AML) tumors. The findings were also verified by looking at samples from AML patients that were collected throughout the course of treatment and relapse.

"Acute myeloid leukemia can be put into remission with chemotherapy, but it almost always comes back, and when it does it's incurable," said senior author Dr. Ari M. Melnick, the Gebroe Family Professor of Hematology and Medical Oncology and a member of the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine. "A longstanding question in the field has been, 'Why can't you get rid of all the cancer cells?' A similar question can be posed for many other types of aggressive cancer in addition to AML."

For years, cancer researchers have studied how tumors are able to rebound after they appear to be completely wiped out by chemotherapy. One theory has been that because not all cells within a tumor are the same at the genetic level--a condition called tumor heterogeneity--a small subset of cells are able to resist treatment and begin growing again. Another theory involves the idea of tumor stem cells--that some of the cells within a tumor have special properties that allow them to re-form a tumor after chemotherapy has been given.

The idea that senescence is involved does not replace these other theories. In fact, it could provide new insight into explaining these other processes, Dr. Melnick said.

In the study, the researchers found that when AML cells were exposed to chemotherapy, a subset of the cells went into a state of hibernation, or senescence, while at the same time assuming a condition that looked very much like inflammation. They looked similar to cells that have undergone an injury and need to promote wound healing--shutting down the majority of their functions while recruiting immune cells to nurse them back to health.

"These characteristics are also commonly seen in developing embryos that temporarily shut down their growth due to lack of nutrition, a state called embryonic diapause," Dr. Melnick explained. "It's not a special process, but normal biological activity that's playing out in the context of tumors."

Further research revealed that this inflammatory senescent state was induced by a protein called ATR, suggesting that blocking ATR could be a way to prevent cancer cells from adopting this condition. The investigators tested this hypothesis in the lab and confirmed that giving leukemia cells an ATR inhibitor before chemotherapy prevented them from entering senescence, thereby allowing chemotherapy to kill all of the cells.

Importantly, studies published at the same time from two other groups reported that the role of senescence is important not just for AML, but for recurrent cases of breast cancer, prostate cancer and gastrointestinal cancers as well. Dr. Melnick was a contributor to one of those other studies.

Dr. Melnick and his colleagues are now working with companies that make ATR inhibitors to find a way to translate these findings to the clinic. However, much more research is needed, because many questions remain about when and how ATR inhibitors would need to be given.

"Timing will be very critical," he said. "We still have a lot to work out in the laboratory before we can study this in patients."

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Dr. Cihangir Duy, a former postdoctoral fellow in Dr. Melnick's lab, was the study's first author. Dr. Duy now leads his own lab at Fox Chase Cancer Center in Philadelphia.

Dr. Ari Melnick has been a paid consultant for KDAC Therapeutics, Epizyme, and Constellation Pharmaceuticals.