Extraordinary carbon emissions from El Nino-induced biomass burning estimated using Japanese aircraft and shipboard observations in Equatorial Asia

NATIONAL INSTITUTE FOR ENVIRONMENTAL STUDIES

 VIDEO: A MOVIE TO DEMONSTRATE THE AIRCRAFT AND SHIP OBSERVATIONS AND OVERVIEW THE RESULTS. view more 

CREDIT: NIES

Equatorial Asia, which includes Indonesia, Malaysia, Papua New Guinea, and surrounding areas, experienced devastating biomass burning in 2015 due to the severe drought condition induced by the extreme El Niño and a positive anomaly of the Indian Ocean dipole. This biomass burning emitted a significant amount of carbon, mainly in the form of carbon dioxide (CO2), into the atmosphere.

Equatorial Asia has very few ground-based stations that observe CO2 and other related atmospheric constitutents. Meanwhile, a few satellites could observe atmospheric CO2; however, their observations were less available and subject to errors due to cumulus cloulds typical in the tropics and smokes from the biomass burning.

To estimate the fire-induced carbon emissions from Equatorial Asia for 2015, the research team of the National Institute for Envrionmental Studies (NIES), Japan, and Meteorological Research Institute (MRI), Japan, expoloited high-precision observations onboard commercial passenger aircraft and a cargo ship that traveled in Equatorial Asia. These observations are unique because measurements are made on a moving platform, enabling to capture three-dimensional gradients of atmospheric CO2 concentrations. The aircraft observations are conducted by the NIES-MRI collaborative research project named CONTRAIL. The shipboard observations are operated by NIES as a part of the Global Environmental Monitoring project.

Using these aircraft and ship observations, the team performed an inverse analysis, which is based on numerical simulations of atmospheric transport, and estimated that the amount of carbon emitted from Equatorial Asia in September - October 2015 was 273 Tg C. The validity of the simulation-based analysis was carefully evaluated by comparing the simulated atomospheric concentrations with those of the observations, not only for CO2, but also for carbon monoxide, which was used as a proxy for combustion sources. In fact, this estimate is slightly smaller than the estimates of previous studies. However, nearly 300 Tg C emissions for only two months are extraordinary because they are comparable to the annual CO2 emissions from Japan.

"Our analysis is the first study that used in-situ high-precision observations for estimating the fire-induced emissions from Equatorial Asia for 2015, which contributes to improving our understanding of biomass burning in this region. It is considered that biomass burning here is dominated by fires in peatland, which has a remarkably high carbon density. Because Equatorial Asia has a significant amount of peatland, the region has a distinct role in the global carbon cycle despite its small terrestrial coverage", Yosuke Niwa (NIES & MRI), the leading author of the study, said. "Peatland forms over thousands of years. Therefore, it is difficult to restore carbon in burnt peatland. Meanwhile, forests could recover by taking CO2 from the atmosphere. However, such CO2 uptake by forest regrowth would not be large enough if the burnt land was converted to a crop field or fires frequently occurred at the same place", said Akihiko Ito (NIES), a coauthor of the study who works on terrestrial biosphere simulations. "It is important to keep on monitoring atmospheric CO2 concentrations. Despite difficult circumstances due to the COVID-19 pandemic, these observations are ongoing thanks to great efforts of the commercial companies that operate the aircraft and the ship. To provide useful information for mitigating climate change, we will continue these observations for many years to come", Toshinobu Machida (NIES), the leader of the CONTRAIL project, said.

CAPTION

Locations of the observations obtained by aircraft (magenta) and ship (blue) for Nov 2014 - Jan 2016. The orange region indicates Equatorial Asia, the target region of this study.

CREDIT

NIES

Mammalian-like hippocampal activity in a food-caching songbird

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

Tufted titmice - tiny songbirds with exceptional memories - process spatial memory using mammalian-like neural mechanisms, researchers report. Food-caching birds like the tufted titmouse are extreme memory specialists and can remember the precise locations of thousands of hidden food stores in the environment. Because of this, they are often regarded as a textbook model of spatial memory and an iconic example of higher cognition in animals. Although spatial memory is observed widely among vertebrates, the hippocampus-like brain regions responsible for it are anatomically distinct between vertebrate clades. As a result, it's been widely assumed that non-mammals use fundamentally different neural mechanisms for memory. Using electrophysical recordings from freely behaving birds, Hannah Payne and colleagues analyzed neuronal activity in the hippocampus homolog of the tufted titmouse and zebra finch - bird species that do, and do not display food-caching behavior, respectively. Payne et al. found mammalian-like neural activity in the titmouse hippocampus, including sharp-wave ripples and anatomically organized place cells. However, compared to titmice, spatial activity was weaker and less abundant in the non-food-caching zebra finches. The findings suggest that neural mechanisms underlying spatial memory are similar between birds and mammals and conserved across widely divergent hippocampal brain circuits.

 

Stakeholders' sentiment can make or break a new CEO

New study finds that stakeholders' sentiment toward a new CEO has a stronger effect on post succession performance than the CEO's previous experience and fit and this is more critical for new external CEOs

BOCCONI UNIVERSITY

Research News

IMAGE: DOVEV LAVIE, BOCCONI UNIVERSITY view more 

CREDIT: PAOLO TONATO

When a CEO steps down or is dismissed, the attention of the board is on how to choose the right executive to succeed that CEO. However, Bocconi University professor Dovev Lavie claims that managing the process of introducing the new CEO and choking the negative sentiment that can arise among stakeholders in a moment of uncertainty could be a more critical task, especially when the new CEO comes from outside the firm.

The effect of such a negative sentiment, which is a form of psychological bias, on a firm's performance is stronger than the implications of the new CEO's previous experience and fit between the CEO's corporate background and the appointing firm's characteristics.

Professor Lavie and co-authors Thomas Keil (University of Zurich) and Stevo Pavi?evi? (Frankfurt School of Finance and Management), in a paper in-press on the Academy of Management Journal, investigate the link between the appointment of an outside CEO and a firm's performance. The appointment of outside CEOs has become increasingly common in recent years, with about a third of appointed CEOs originating from outside the firm. Yet most studies report that they underperform compared to inside CEOs and exhibit greater performance variability.

Analyzing 1,275 appointments in 882 publicly listed US firms during 2001-2014, the study refines existing CEO-centric theories on the effect of a CEO's previous experience and fit, while introducing a novel stakeholder-centric perspective, which relates post-succession performance to the sentiment of stakeholders toward CEO appointments.

"Our findings reveal that, counter to expectations, the length and breadth of a CEO's executive experience do not enhance firm performance, nor explain the performance differences between inside and outside CEOs," Professor Lavie says. "Rather, the misfit between the CEO's corporate background and the appointing firm's characteristics, in terms of industry, firm size and firm age, undermines firm performance, especially following outside CEO appointments."

More importantly, the authors contend that negative sentiment originating from the firm's stakeholders toward the appointment of the CEO may hamper a new CEO's effectiveness, and hence firm performance.

They capture stakeholder sentiment using textual analysis of 27,092 press items around the announcement of CEO successions and further study the reactions of relevant stakeholders, such as analysts' buy/sell recommendations, executives' sales of their firm's stocks, and employees' ratings of their new CEOs.

Negative sentiment turns out to undermine post-succession performance and this effect is more significant than that of corporate misfit. Negative sentiment, if left unattended, can escalate, leading to increased scrutiny, deprived support, organizational resistance, and reputational damage.

Both inside and outside CEOs can suffer negative sentiment, but the effects are stronger for outside CEOs because they are less familiar with the hiring firm and cannot readily use workplace politics and personal networks to muffle them. The study finds that outside CEOs have an advantage so long as their corporate background makes a good fit with the hiring firm and the negative sentiment is effectively dealt with.

"Boards should develop practices that enable outside CEOs to quickly integrate into the firm and its social networks, while carefully and promptly managing the reactions of all stakeholders. For their part, newly appointed CEOs should consider tactics for offsetting negative sentiment before it escalates, e.g., by restructuring the top management team, leveraging public relations, or building social ties in the firm prior to taking office," the authors suggest.

###

 

Guiding principles for work shift duration published by AASM and SRS

Key factors for determining shift length will help manage fatigue-related risks while meeting operational demands

AMERICAN ACADEMY OF SLEEP MEDICINE

Research News

DARIEN, Ill. -- The American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) have published evidence-based guiding principles to help employers determine optimal work shift durations for their workplace. With a process that assesses risks, considers countermeasures, and institutes an informed approach to determine and evaluate shift durations, employers can make shift duration decisions that manage fatigue-related risks while also maintaining high productivity and safety.

"Historically, shift duration guidance has set maximum shift durations in a one-size-fits-all approach that focused primarily on physical fatigue," said Dr. Indira Gurubhagavatula, corresponding author for the paper and a physician in the division of sleep medicine of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. "Rather than providing a single, generic recommendation, these new guiding principles involve taking a more holistic view when setting customized shift durations for each individual workplace, considering not just physical fatigue, but mental fatigue, time of day, job requirements, safety risks, lifestyle factors, and health."

Determining optimal work shift durations is an important issue that affects performance and safety - both at work and in the community. Organizations, communities, workers, and regulatory agencies struggle with how to best manage shift durations. Scientific evidence that is essential for designing effective solutions has grown substantially in recent years, providing a foundation for making informed decisions about shift durations while preserving the integrity and feasibility of workplace operations.

When establishing work shift durations, the guiding principles recommend an approach that includes three strategies: (1) assess risk factors, (2) consider countermeasures, and (3) institute an informed approach.

Assess Risk Factors

The duration of work shifts is linked to adverse performance, safety, and health outcomes, especially when shifts are misaligned with a worker's biological clock. Work shift timing, workload factors, commute time, other demands on people's time, and individual biological factors all contribute to the impact of shift durations.

"An overall assessment of the risk factors associated with work shifts in a particular setting is key to making informed decisions about optimal shift durations in that setting," said senior author Hans Van Dongen, director of the Sleep and Performance Research Center at Washington State University in Spokane.

Consider Countermeasures

Countermeasure tools and strategies can be deployed in the workplace to reduce or manage risks associated with extended work shifts. Some are aimed at increasing sleep through nap opportunities or improving alertness with strategic caffeine consumption, for instance. Other countermeasures target operational risk outcomes; examples include quality control checks, warning systems, and team-based work strategies.

The choice of countermeasures should be based on assessment of the risks to be managed. After implementation, both positive and negative effects should be monitored to identify any unintended consequences and evaluate opportunities for improvement.

Institute an Informed Approach

Determining appropriate shift durations often involves finding an optimal compromise between competing goals. To ensure everyone understands the trade-offs, the decision-making process about shift durations should be fully informed, transparent, and based on scientific evidence. It should incorporate representatives of all stakeholders, and those whose lives and livelihoods would be directly impacted by changes to shift durations should be encouraged to participate in the decision-making process.

Any changes made to shift duration work policies should be monitored and evaluated, with corrective action taken in the event of unintended consequences.

The paper providing the recommendations and the supporting scientific evidence, "Guiding Principles for Determining Work Shift Duration and Addressing the Effects of Work Shift Duration on Performance, Safety, and Health," will be co-published July 15, 2021, in the peer-reviewed scientific publications the Journal of Clinical Sleep Medicine and SLEEP. Links to the paper will be active when the embargo lifts.

###

About the American Academy of Sleep Medicine

Established in 1975, the AASM advances sleep care and enhances sleep health to improve lives. The AASM has a combined membership of 11,000 accredited member sleep centers and individual members, including physicians, scientists, and other health care professionals (aasm.org). The monthly, peer-reviewed Journal of Clinical Sleep Medicine is the official publication of the AASM.

About the Sleep Research Society

The Sleep Research Society (SRS) is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals SLEEP and SLEEP Advances.

Thinking without a brain

Studies in brainless slime molds reveal that they use physical cues to decide where to grow

WYSS INSTITUTE FOR BIOLOGICALLY INSPIRED ENGINEERING AT HARVARD

Research News

If you didn't have a brain, could you still figure out where you were and navigate your surroundings? Thanks to new research on slime molds, the answer may be "yes." Scientists from the Wyss Institute at Harvard University and the Allen Discovery Center at Tufts University have discovered that a brainless slime mold called Physarum polycephalum uses its body to sense mechanical cues in its surrounding environment, and performs computations similar to what we call "thinking" to decide in which direction to grow based on that information. Unlike previous studies with Physarum, these results were obtained without giving the organism any food or chemical signals to influence its behavior. The study is published in Advanced Materials.

"People are becoming more interested in Physarum because it doesn't have a brain but it can still perform a lot of the behaviors that we associate with thinking, like solving mazes, learning new things, and predicting events," said first author Nirosha Murugan, a former member of the Allen Discovery Center who is now an Assistant Professor at Algoma University in Ontario, Canada. "Figuring out how proto-intelligent life manages to do this type of computation gives us more insight into the underpinnings of animal cognition and behavior, including our own."

Slimy action at a distance

Slime molds are amoeba-like organisms that can grow to be up to several feet long, and help break down decomposing matter in the environment like rotting logs, mulch, and dead leaves. A single Physarum creature consists of a membrane containing many cellular nuclei floating within a shared cytoplasm, creating a structure called a syncytium. Physarum moves by shuttling its watery cytoplasm back and forth throughout the entire length of its body in regular waves, a unique process known as shuttle streaming.

"With most animals, we can't see what's changing inside the brain as the animal makes decisions. Physarum offers a really exciting scientific opportunity because we can observe its decisions about where to move in real-time by watching how its shuttle streaming behavior changes," said Murugan. While previous studies have shown that Physarum moves in response to chemicals and light, Murugan and her team wanted to know if it could make decisions about where to move based on physical cues in its environment alone.

The researchers placed Physarum specimens in the center of petri dishes coated with a semi-flexible agar gel and placed either one or three small glass discs next to each other atop the gel on opposite sides of each dish. They then allowed the organisms to grow freely in the dark over the course of 24 hours, and tracked their growth patterns. For the first 12 to 14 hours, the Physarum grew outwards evenly in all directions; after that, however, the specimens extended a long branch that grew directly over the surface of the gel toward the three-disc region 70% of the time. Remarkably, the Physarum chose to grow toward the greater mass without first physically exploring the area to confirm that it did indeed contain the larger object.

How did it accomplish this exploration of its surroundings before physically going there? The scientists were determined to find out.

It's all relative

The researchers experimented with several variables to see how they impacted Physarum's growth decisions, and noticed something unusual: when they stacked the same three discs on top of each other, the organism seemed to lose its ability to distinguish between the three discs and the single disc. It grew toward both sides of the dish at roughly equal rates, despite the fact that the three stacked discs still had greater mass. Clearly, Physarum was using another factor beyond mass to decide where to grow.

To figure out the missing piece of the puzzle, the scientists used computer modeling to create a simulation of their experiment to explore how changing the mass of the discs would impact the amount of stress (force) and strain (deformation) applied to the semi-flexible gel and the attached growing Physarum. As they expected, larger masses increased the amount of strain, but the simulation revealed that the strain patterns the masses produced changed, depending on the arrangement of the discs.

"Imagine that you are driving on the highway at night and looking for a town to stop at. You see two different arrangements of light on the horizon: a single bright point, and a cluster of less-bright points. While the single point is brighter, the cluster of points lights up a wider area that is more likely to indicate a town, and so you head there," said co-author Richard Novak, Ph.D., a Lead Staff Engineer at the Wyss Institute. "The patterns of light in this example are analogous to the patterns of mechanical strain produced by different arrangements of mass in our model. Our experiments confirmed that Physarum can physically sense them and make decisions based on patterns rather than simply on signal intensity."

The team's research demonstrated that this brainless creature was not simply growing toward the heaviest thing it could sense - it was making a calculated decision about where to grow based on the relative patterns of strain it detected in its environment.

But how was it detecting these strain patterns? The scientists suspected it had to do with Physarum's ability to rhythmically contract and tug on its substrate, because the pulsing and sensing of the resultant changes in substrate deformation allows the organism to gain information about its surroundings. Other animals have special channel proteins in their cell membranes called TRP-like proteins that detect stretching, and co-author and Wyss Institute Founding Director Donald Ingber, M.D., Ph.D had previously shown that one of these TRP proteins mediates mechanosensing in human cells. When the team created a potent TRP channel-blocking drug and applied it to Physarum, the organism lost its ability to distinguish between high and low masses, only selecting the high-mass region in 11% of the trials and selecting both high- and low-mass regions in 71% of trials.

"Our discovery of this slime mold's use of biomechanics to probe and react to its surrounding environment underscores how early this ability evolved in living organisms, and how closely related intelligence, behavior, and morphogenesis are. In this organism, which grows out to interact with the world, its shape change is its behavior. Other research has shown that similar strategies are used by cells in more complex animals, including neurons, stem cells, and cancer cells. This work in Physarum offers a new model in which to explore the ways in which evolution uses physics to implement primitive cognition that drives form and function," said corresponding author Mike Levin, Ph.D., a Wyss Associate Faculty member who is also the Vannevar Bush Chair and serves and Director of the Allen Discovery Center at Tufts University.

The research team is continuing its work on Physarum, including investigating at what point in time it makes the decision to switch its growth pattern from generalized sampling of its environment to directed growth toward a target. They are also exploring how other physical factors like acceleration and nutrient transport could affect Physarum's growth and behavior.

"This study confirms once again that mechanical forces play as important a role in the control of cell behavior and development as chemicals and genes, and the process of mechanosensation uncovered in this simple brainless organism is amazingly similar to what is seen in all species, including humans," said Ingber. "Thus, a deeper understanding how organisms use biomechanical information to make decisions will help us to better understand our our own bodies and brains, and perhaps even provide insight into new bioinspired forms of computation." Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children's Hospital, and Professor of Bioengineering at the Harvard John A. Paulson School of Engineering and Applied Sciences.

###

Additional authors of the paper include Daniel Kaltman, Paul Jin, Melanie Chien, and Cuong Nguyen from the Allen Center for Discovery at Tufts University, Ramses Flores from the Wyss Institute, and Anna Kane from both the Allen Center and the Wyss Institute.

This research was supported by the Allen Discovery Center program through The Paul G. Allen Frontiers Group, Defense Advanced Research Projects Agency (DARPA) under Cooperative Agreement Number HR0011-18-2-0022, Lifelong Learning Machines program from DARPA/MTO, and the Wyss Institute at Harvard University.

 

Nitrogen-producing process of anammox bacterium finally uncovered

RADBOUD UNIVERSITY NIJMEGEN

Research News

After years of research, the molecular structure of the enzyme responsible for a large part of the global nitrate and nitrogen production by bacteria has finally been uncovered. The anammox bacterium and other bacteria use this enzyme to convert toxic nitrite into nitrate. Now that the working of the enzyme has become clear, new possibilities have opened for the improved deployment of the anammox bacterium for power generation from wastewater and for the production of rocket fuel. Researchers from Radboud University and the Max Planck Institutes in Heidelberg and Frankfurt published a paper on the subject in Nature Microbiology today.

Nitrogen-consuming bacteria like the anammox bacterium require the nitrite oxidoreductase enzyme (NXR) to convert toxic nitrite into nitrate. The enzyme fulfils a central role in nature's nitrogen cycle. Significant amounts of ammonium end up in soil due to activities such as the use of fertilisers. The ammonium is subsequently converted into nitrate, which is water-soluble and therefore easily washes away into groundwater and surface water. This process forms an important part of the reason why too much nitrogen has such an environmental impact.

Complex molecule

"Despite the enzyme being such a vital part of the nitrogen cycle, we knew relatively little about how it worked", says Mike Jetten, professor of Ecological Microbiology at Radboud University. "It took us more than ten years to map the molecular structure of this enzyme in the anammox bacterium."

"NXR turns out to have a complex structure and contains unexpected parts", explains Thomas Barends of the Max Planck Institute for Medical Research in Heidelberg. "Together with our colleagues in Frankfurt, we found a building block that ensures the protein combines into long threads. We have also gained greater insight into the way proteins are able organise inside a cell in general."

Wastewater and rocket fuel

The knowledge of the inner working of NXR will help in the deployment of the anammox bacterium in interesting applications. Jetten: "Anammox requires this enzyme to grow, but it also grows slowly by nature. We might now be able to suppress the bottlenecks in the growing process, allowing for the application of the bacterium in smaller and faster installations."

Nijmegen microbiologists have long studied the properties of this unique anammox bacterium. It is the only known bacterium that is able to convert harmful ammonium into harmless nitrogen gas without requiring oxygen in the process. Since its discovery, anammox has been widely used for wastewater treatment.

A year ago, the microbiologists discovered that the bacterium can help to generate power from wastewater. "This - previously impossible - reaction was made possible by circumventing the NXR enzyme. Another point on our bucket list is to have anammox produce rocket fuel on a large scale. To achieve this, we will need to know how to circumvent the enzyme even more efficiently: this will cause the bacterium to focus less of growth and more on the synthesis of the by-product hydrazine, one of the compounds used in liquid rocket fuel."

###

 

Study shows strong association between perceived risk, availability and past-year cannabis use

Individuals who perceived cannabis as both low-risk and available were 22 times more likely to have used cannabis in the past year than those perceiving cannabis as both high-risk and unavailable

COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH

Research News

Combined perceptions of the risk and availability of cannabis influence the risk of cannabis use more than perceived risk and perceived availability alone, according to a new study at Columbia University Mailman School of Public Health. Researchers observed that those who perceived cannabis as low-risk and available were more likely to report using the drug in the past year and almost daily compared to those individuals who perceived cannabis as high-risk and unavailable. This is the first study to consider the joint effects of perceived risk and perceived availability. The results are published in the journal Drug and Alcohol Dependence.

"Our study described the evolution of joint perceptions of cannabis risk and availability from 2002-2018 and estimated the relationship between combined perceptions and past-year cannabis use, frequent use, and cannabis use disorder," said Natalie Levy, MPH, doctoral student in the Department of Epidemiology at Columbia Mailman School, and first author. "Studying perceived risk and availability in conjunction revealed more nuanced patterns than considering each perception in isolation.."

Using data on 949,285 participants from the National Surveys on Drug Use and Health from 2002-2018, researchers observed that the prevalence of perceiving cannabis use as low-risk doubled over this period while the prevalence of perceiving cannabis as available increased only marginally. When looking at joint categories of perceived risk and perceived availability, they found that prevalence of perceiving cannabis as both low-risk and available increased, from 17 percent in 2002 to 36 percent in 2018 while the proportion of the population perceiving cannabis as high-risk and available or high-risk and unavailable declined. By 2018, a larger proportion of the population perceived marijuana as low-risk and available (36 percent) than both high-risk and available and high-risk and unavailable, at 26 percent and 27 percent, respectively.

Individuals who perceived cannabis as low-risk were six times more likely to have used cannabis in the past-year than individuals who perceived the drug as high-risk. Similarly, individuals who perceived cannabis as available were five times more likely to have used cannabis in the past year than individuals who perceived it as unavailable. However, individuals who perceived marijuana as both low-risk and available were 22 times more likely to have used the drug in the past year than those who perceived cannabis as high-risk and unavailable.

In 2018, most individuals who reported no past-year cannabis use perceived cannabis as high-risk, whether or not they distinguished between its availability or non-availability. In contrast, the majority of individuals who used cannabis in the past year perceived the drug as low-risk and available and this perception rose to even higher levels among those reporting frequent use.

Cannabis perceptions also differed by gender. Overall, a larger proportion of males viewed cannabis as lower risk and more available compared with females, but patterns differed by age. "We found minimal differences in perceptions by gender in the 12-17-year age group while among all those 18 years of age and older, the prevalence of perceiving cannabis as low-risk and available was higher for males than females; perceiving cannabis as high-risk and unavailable was more common among females in every year," noted Levy.

"Our results provide an important starting point for exploring specific hypotheses regarding the effects of perceptions on individual cannabis outcomes and highlight the importance of exploring perceived risk and availability together," said Silvia Martins, MD, PhD, Columbia Mailman School associate professor of Epidemiology, director of the Substance Use Epidemiology Unit of the Department of Epidemiology, and senior author. "For example, our findings suggest that prevention efforts that focus only on the risks of cannabis use may be less effective among individuals who perceive cannabis as easily available.

"Trends in perceptions - especially among younger age groups -- may also identify priority groups for intervention," observed Levy. "Further understanding of these relationships is particularly important in light of rapidly changing cannabis policies, a contextual factor that may influence perceptions of both risk and availability of cannabis and subsequent use."

###

Co-authors are Pia Mauro, Christine Mauro, and Luis Segura, Columbia Mailman School of Public Health.

The study was supported by National Institutes of Health, grants R01DA037866 and K01DA045224.

Columbia University Mailman School of Public Health

Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the seventh largest recipient of NIH grants among schools of public health. Its nearly 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change and health, and public health preparedness. It is a leader in public health education with more than 1,300 graduate students from 55 nations pursuing a variety of master's and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit http://www.mailman.columbia.edu.

 

Study finds adolescent girls and young women in Africa will use HIV prevention products

Interim results of the REACH study of daily oral PrEP and monthly dapivirine vaginal ring presented at IAS 2021 - the 11th IAS Conference on HIV Science

MICROBICIDE TRIALS NETWORK

Research News

Adolescent girls and young women can and will use HIV prevention products with consistency, according to interim results of a study of two different methods: daily use of the antiretroviral (ARV) tablet Truvada® as oral pre-exposure prophylaxis (PrEP) and the monthly dapivirine vaginal ring, a new HIV prevention product currently under regulatory review in several countries.

To provide protection against HIV, both must be used consistently- daily, for oral PrEP, and for the ring, a full month at a time - which previous studies of these products found to be especially challenging for younger women.

This was not the case in an ongoing study, known as REACH (Reversing the Epidemic in Africa with Choices in HIV prevention), being conducted at four clinical research sites in Uganda, South Africa and Zimbabwe by the National Institutes of Health-funded Microbicide Trials Network (MTN). The vast majority (97 percent) of the study's 247 participants, who were between the ages of 16 and 21 when they enrolled, used the vaginal ring and daily oral PrEP some or all of the time. Fewer than three percent of participants used neither of the products, according to laboratory tests for adherence.

These and other results from the study's first two periods, during which participants were asked to use each of the products for six months, are being reported at IAS 2021 - the 11th IAS Conference on HIV Science - taking place virtually from 18-21 July, and were featured in an official IAS press conference today.

Both approaches received high marks from the study's participants: during the six months they were asked to use the monthly dapivirine ring, 88 percent said they liked it, and during the period when they were assigned to use oral PrEP, 64 percent said they liked the daily pill-taking regimen.

The research team attributes the study's findings of high product adherence and acceptability to the ongoing support measures, tailored for this population, and nonjudgmental counseling approach provided as part of the study.

"In many ways, these results exceeded even our own expectations, yet at the same time, it's not surprising to find that these young women have the capacity and desire to protect themselves against HIV. They simply need to feel empowered and have the agency to make choices based on what they feel is right for them," said Gonasagrie (Lulu) Nair, MBChB, MPH, REACH protocol chair and senior lecturer, Centre for Medical Ethics and Law, Faculty of Medicine, at Stellenbosch University in South Africa.

Globally, more than half of all people living with HIV are women, and in sub-Saharan Africa, women account for more than 60 percent of adults with HIV. Rates of infection are especially high among adolescent girls and young women. According to UNAIDS, in 2020, one in four new infections in sub-Saharan Africa were in young women ages 15-24, despite making up only 10 percent of the population.

REACH, also known as MTN-034, was designed to fill important gaps in information about the safety and acceptability of the dapivirine ring and Truvada (a tablet containing a combination of the ARV drugs tenofovir disoproxil fumarate and emtricitabine) as oral PrEP in girls younger than 18. Of the 247 participants in REACH, 86 (35 percent) were age 16 or 17 at the time of enrollment. The study is also collecting important data that will supplement existing safety and acceptability data among young women ages 18-21.

Indeed, interim results also found both Truvada as oral PrEP and the dapivirine ring were well tolerated with no safety concerns. As REACH is still an ongoing study, the safety of these products continues to be monitored by the research team.

Information about the safety of the ring among adolescent girls is especially important. The ring, which was developed by the nonprofit International Partnership for Microbicides (IPM), would be the first biomedical prevention method designed specifically for women, and the first long-acting method. However, because the product's Phase III trials were conducted among cisgender women ages 18-45, additional data would be needed to support the ring's use in women younger than 18. Pending its final results, data from REACH, as well as from the MTN-023/IPM 030 study among adolescent girls ages 15 to 17 in the United States, will be submitted to regulators so that they may consider approving the ring for adolescent girls.

REACH also seeks to understand what adolescent girls and young women need to help them to use the dapivirine ring and oral PrEP as consistently as possible, and their preferences for either or both. After having experienced using both of the products, each for six months, participants then choose which one they want to use for the remaining six months of the study, or to choose neither. Moreover, participants are free to change their minds. The choice phase of REACH is still ongoing, with approximately 50 participants still in the study.

As researchers are reporting at IAS 2021, adherence to both products was high during the first two periods of the study. Adherence to oral PrEP was based on levels of drug in blood samples taken at each monthly visit. For the ring, researchers looked at the amount of residual drug left in rings participants returned after a month of use. The ring contains 25mg of the ARV dapivirine, about 4 mg of which is released into the vagina when used continuously for 28 days.

Using these measures, researchers determined that during the six months participants were assigned to use oral PrEP, 39.9 percent of the participants had drug levels that suggested they used oral PrEP at least some of the time, meaning they took the tablets between one and three times a week; and 58.6 percent were classified as high users, whose drug levels suggested they took the tablets at least four times a week, which among men who have sex with men has been associated with 100 percent protection. The threshold for protection in cisgender women has yet to be determined. For the ring, drug levels in returned rings suggested that 45.4 percent used it at least some of the time, and that 50.2 percent used the ring for the full month. Full compliance to oral PrEP, whereby blood levels indicate taking at least six pills per week, was evident for 22 percent of the participants.

"It's important to note that our aim is not to make direct comparisons between oral PrEP and the ring, which wouldn't be feasible anyway because the methods for measuring adherence are not the same. Rather, the study aims to compare participants' adherence to the ring and oral PrEP in this study with what had been observed among young women in other trials of these products, as a way to understand whether these are feasible options for young women and whether they are willing to use either or both," explained Dr. Nair. "The answer, as these results make clear, is yes."

In the two Phase III trials of the ring, younger women used the ring least regularly, and as a group, had the lowest rates of risk reduction. In ASPIRE, for example, the ring was not shown to be effective among women ages 18-21, with levels of drug in returned rings also indicating low adherence to use. Likewise, daily pill taking was more challenging for younger women in the Phase III trials of oral PrEP (VOICE and FEM-PrEP). Moreover, results of the HPTN 082 open-label study among adolescent girls and young women in South Africa and Zimbabwe, found that 85 percent of the participants used oral PrEP with some regularity at the beginning of the study, but when clinic visits changed from monthly to every three months, there was a steep decline. Three months into the study, fewer than 25 percent were using oral PrEP, and by month 12, it was only nine percent.

"What strikes me most about REACH is that not only are we seeing high adherence, but persistence appears to be high as well. Clearly, the ongoing support and individual attention paid to participants seems to make a difference," noted Connie Celum, M.D., M.P.H., professor of global health and medicine and director of the International Clinical Research Center at the University of Washington in Seattle, who is a REACH protocol co-chair and led the HPTN 082 study. "To see this kind of high adherence - it's pretty remarkable, especially during this time of COVID-19."

As part of REACH, study participants receive extensive support and counseling focused on helping them to use their assigned (or chosen) product as best they can. Every monthly visit includes a meeting with a counselor, and participants can also choose from a menu of additional forms of support, including daily text messages or weekly check-ins by phone; having a "Peer Buddy"; and adherence support groups. At some sessions, participants receive their individual adherence test results as a way to help facilitate discussion about adherence and how it relates to HIV risk reduction. Results are presented in terms of what they may mean for level of protection they are receiving and given without judgement.

"We've tried to empower these young women by letting them take control of their own health and behaviors and to make their own decisions. If participants don't want to or cannot use either the ring or oral PrEP, we simply want to understand the reasons why, while also seeing what kind of support may help. And if they change their mind, that's okay as well, because as their circumstances change, so will their needs and preferences for HIV prevention," added Kenneth Ngure, Ph.D., MPH, chair of the department of community health at Jomo Kenyatta University of Agriculture & Technology in Nairobi, Kenya, and REACH protocol co-chair.

REACH began in February 2019 and is expected to be completed by October 2021, with final results, including outcomes from the choice period, anticipated in early-to-mid 2022.

While the study was originally designed to enroll 300 participants, 100 of whom would be 16- and 17-years old, in March 2020, in the face of the emerging COVID-19 pandemic, MTN and study leadership decided to close the study to further enrollment so that fullest attention could be paid to ensuring the safety of its current participants as well as clinic staff. By this time, REACH had already enrolled 247 participants, including 86 who were under the age of 18, such that the study would still be able to provide sufficient data about the safety of the dapivirine vaginal ring and oral PrEP in adolescent girls and young women, and to do so in less time as well.

Just four months later, in July 2020, the ring received a positive opinion from the European Medicines Agency (EMA) for its use among women ages 18 and older in developing countries, and soon after, was added to the World Health Organization's (WHO) list of pre-qualified medicines. IPM is now seeking approval of the ring in eastern and southern Africa, including in countries where REACH is being conducted. Just yesterday, the ring received its first approval, which came from the Medicines Control Authority of Zimbabwe. IPM is also seeking regulatory approval from the US Food and Drug Administration.

In anticipation of the ring's potential approval, WHO's updated guidelines for HIV prevention, published in March 2021, recommend the ring as an additional HIV prevention choice for women at substantial risk of HIV, while also acknowledging that study's like REACH will help to better understand ways to support consistent and persistent use of both PrEP and the ring in adolescent girls and young women.

The clinical research sites (CRSs) where REACH is being conducted are Makerere University-Johns Hopkins University CRS in Kampala, Uganda; the University of Zimbabwe College of Health Sciences Clinical Trials Research Centre Spilhaus CRS, Harare; and in South Africa, the Wits Reproductive Health and HIV Institute in Johannesburg and the Emavundleni CRS of the Desmond Tutu HIV Foundation in Cape Town.

###

MTN and the REACH study are supported by U.S. National Institutes of Health grants UM1AI068633, UM1AI068615 and UM1AI106707.

The study products for REACH were provided by the International Partnership for Microbicides (IPM) and Gilead Sciences.

More information about REACH is at mtnstopshiv.org/reach-study and http://www.mtnstopshiv.org/news/studies/mtn034,.

To learn more about the monthly dapivirine ring, visit https://www.ipmglobal.org/

Trends in Diversity and Representativeness of Health Care Workers in the United States, 2000 to 2019

Research Letter 

Health Policy

July 15, 2021

Dan P. Ly, MD, PhD, MPP^1,2; Anupam B. Jena, MD, PhD^3,4,5

Author Affiliations Article Information

JAMA Netw Open. 2021;4(7):e2117086. doi:10.1001/jamanetworkopen.2021.17086

Introduction

Despite evidence that greater diversity among health care workers may allow them to better care for patients with diverse cultural, social, economic, and clinical needs,^1-3 data are limited on trends in diversity and representativeness of US health care workers by occupation. Using US Census data from 2000 to 2019, we examined national trends in representativeness in select health care occupations by race/ethnicity and sex.

Methods

In this cross-sectional study, we used 2 data sources: (1) the Decennial Census long form, a nationally representative, US Census–administered survey, from 2000, and (2) the American Community Survey, a nationally representative Census-administered survey, from 2001 to 2019. Response rates for both exceeded 90%.^4,5 This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. The University of California Los Angeles institutional review board determined that the study was not human subjects research and therefore exempt from review and the requirement for informed consent.

Occupation, race, (White, Black, American Indian or Alaska Native, Chinese, Japanese, other Asian or Pacific Islander, other race, 2 major races, or ≥3 major races) and ethnicity (not Hispanic, Mexican, Puerto Rican, Cuban, and other Hispanic origin) were self-reported. Participants who selected Chinese, Japanese, or other Asian or Pacific Islander were included into the category Asian. Participants who selected Mexican, Puerto Rican, Cuban, and other were included in the Hispanic category. Participants who selected other race, 2 major races, or 3 or more major races were excluded, leaving 4 groups: non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic. We estimated the composition of select health care occupations (Table 1) by race/ethnicity and sex in 2000 to 2004 and 2015 to 2019. For each occupation, we calculated the change in percentage in each race/ethnicity and sex subgroup between these 2 periods using linear regression. In addition, in each occupation, we assessed the population representativeness of each race/ethnicity and sex subgroup by calculating the ratio of the percentage of a specific subgroup in an occupation (eg, Black male physicians) to the percentage of the US population in that subgroup (eg, Black men).⁶ We used Census-provided sampling weights to make nationally representative estimates. P values were from 2-sided tests, and results were deemed statistically significant at P < .05. Analyses were conducted in Stata version 16.1 (StataCorp).

Results

Our study included 1 648 924 individuals (1 303 496 [79.1%] women; 345 428 [20.9%] men) across 6 health care occupations (Table 1). The percentage of White men in relatively more remunerative occupations (ie, physicians and surgeons, pharmacists, and dentists) decreased between 2000 to 2004 and 2015 to 2019. For example, the percentage of physicians and surgeons who were White men decreased from 54.1% (95% CI, 53.3% to 54.9%) to 43.8% (95% CI, 43.3% to 44.3%) (difference, −10.3 [95% CI, −11.2 to −9.3] percentage points), while the percentage of dentists who were White men decreased 15.6 (95% CI, 13.5 to 17.6) percentage points. Little to no change was observed in the percentage of men from underrepresented minorities in these occupations. For example, no change was observed in the percentage of physicians and surgeons who were Hispanic men (difference, 0.2 [95% CI, −0.2 to 0.6] percentage points) or in the percentage of pharmacists who were Black men (difference, −0.06 [95% CI, −0.8 to 0.6] percentage points). Statistically significant increases were observed in the percentage of both Black and Hispanic women in these 3 occupations. For example, the percentage of pharmacists who were Black women increased 1.3 (95% CI, 0.6 to 2.0) percentage points, and the percentage of dentists who were Hispanic women increased 1.0 (95% CI, 0.4 to 1.7) percentage points. Increases for White and Asian women in these occupations were larger than for Black and Hispanic women.

Significant increases were observed among most minority race/ethnicity and sex subgroups in less remunerative occupations (ie, nurses, therapists, and health care aides). In an analysis of population representativeness in 2015 to 2019, Black and Hispanic men and women remained considerably underrepresented relative to the US population in more remunerative occupations (Table 2).

Discussion

In a nationally representative sample, little to no increase in Black or Hispanic men was observed among physicians and surgeons, pharmacists, and dentists between 2000 and 2019. While there were increases in Black and Hispanic women in these occupations, increases among White and Asian women were larger. Altogether, increases in representation of these 4 subgroups of women were accompanied by large declines in the proportion of White men. Other health care occupations, such as nurses, therapists, and health care aides, had increases across most minority subgroups during the examined period. These results quantify the current representativeness of the US health care workforce and changes in its composition during the past 2 decades. Study limitations include the use of self-reported survey data.

Back to top

Article Information

Accepted for Publication: May 12, 2021.

Published: July 15, 2021. doi:10.1001/jamanetworkopen.2021.17086

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Ly DP et al. JAMA Network Open.

Corresponding Author: Anupam B. Jena, MD, PhD, Department of Health Care Policy, Harvard Medical School, 180 Longwood Ave, Boston, MA 02115 (jena@hcp.med.harvard.edu).

Author Contributions: Dr Ly had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Both authors.

Acquisition, analysis, or interpretation of data: Both authors.

Drafting of the manuscript: Both authors.

Critical revision of the manuscript for important intellectual content: Both authors.

Statistical analysis: Both authors.

Supervision: Jena.

Conflict of Interest Disclosures: Dr Jena reported receiving consulting fees from Pfizer; Bioverativ; Bristol Myers Squibb; Merck, Sharp, and Dohme; Janssen Pharmaceuticals; Edwards Life Sciences; Novartis; Amgen; Eli Lilly and Co; Vertex Pharmaceuticals; AstraZeneca; Celgene; Tesaro; Sanofi Aventis; Precision Health Economics; and Analysis Group outside the submitted work. No other disclosures were reported.

Disclaimer: The views expressed in this manuscript are those of the authors and do not necessarily represent the views of the US Department of Veterans Affairs or the US government.

References

1.

Alsan  M, Garrick  O, Graziani  G.  Does diversity matter for health? experimental evidence from Oakland.   Am Econ Rev 2019; 109: 4071-4111. doi:10.1257/aer.20181446Google ScholarCrossref

2.

Mertz  EA, Wides  CD, Kottek  AM, Calvo  JM, Gates  PE.  Underrepresented minority dentists: quantifying their numbers and characterizing the communities they serve.   Health Aff (Millwood). 2016;35(12):2190-2199. doi:10.1377/hlthaff.2016.1122PubMedGoogle ScholarCrossref

3.

Institute of Medicine. In the nation’s compelling interest: ensuring diversity in the health-care workforce. Accessed May 4, 2021. https://www.nap.edu/catalog/10885/in-the-nations-compelling-interest-ensuring-diversity-in-the-health

4.

Griffin  DH, Love  SP, Obenski  SM. Can the American Community Survey replace the Census long form? Accessed May 4, 2021. http://www.asasrms.org/Proceedings/y2003/Files/JSM2003-000596.pdf

5.

IPUMS USA. Select samples. Accessed May 4, 2021. https://usa.ipums.org/usa-action/samples

6.

Lett  LA, Murdock  HM, Orji  WU, Aysola  J, Sebro  R.  Trends in racial/ethnic representation among US medical students.   JAMA Netw Open. 2019;2(9):e1910490. doi:10.1001/jamanetworkopen.2019.10490
ArticlePubMedGoogle Scholar