How to make up your mind when the glass seems half empty?

Review highlights recent advances in understanding how anxiety can drive ‘pessimistic’ decision making

Peer-Reviewed Publication

KYOTO UNIVERSITY

 

IMAGE: NEUROSCIENTISTS AT KYOTO UNIVERSITY’S INSTITUTE FOR ADVANCED STUDY OF HUMAN BIOLOGY (WPI-ASHBI) HAVE CONNECTED SOME OF THE DOTS TO REVEAL THE BRAIN NETWORKS THAT GIVE ANXIETY INFLUENCE OVER DECISIONS. WRITING IN THE JOURNAL FRONTIERS IN NEUROSCIENCE, THE GROUP HAS PUBLISHED A REVIEW THAT SYNTHESIZES RESULTS FROM YEARS OF BRAIN MEASUREMENTS IN RATS AND PRIMATES AND RELATES THESE FINDINGS TO THE HUMAN BRAIN. view more 

CREDIT: KYOTO UNIVERSITY

KYOTO—Is a new high-income job offer worth accepting if it means commuting an extra hour to work? People often have to make tough choices regarding whether to endure some level of discomfort to take advantage of an opportunity or otherwise walk away from the reward. In making such choices, it turns out that the brain weighs our desire to go for the reward against our desire to avoid the related hardship.

In previous research, negative mental states have been shown to upset this balance between payoff and hardship toward more ‘pessimistic’ decision making and avoidance. For example, scientists know that people experiencing anxiety have a stronger-than-normal desire to avoid negative consequences. And people with depression have a weaker desire to approach the reward in the first place. But there is still much we do not know about how the brain incorporates feelings into decision making. 

Neuroscientists at Kyoto University’s Institute for Advanced Study of Human Biology (WPI-ASHBi) have connected some of the dots to reveal the brain networks that give anxiety influence over decisions. Writing in the journal Frontiers in Neuroscience, the group has published a review that synthesizes results from years of brain measurements in rats and primates and relates these findings to the human brain.

“We are facing a new epidemic of anxiety, and it is important that we understand how our anxiety influences our decision making,” says Ken-ichi Amemori, associate professor in neuroscience at Kyoto University, ASHBi. “There is a real need for a better understanding of what is happening in the brain here. It is very difficult for us to see exactly where and how anxiety manifests in humans, but studies in primate brains have pointed to neurons in the ACC [anterior cingulate cortex] as being important in these decision-making processes.”

Thinking of the brain as an onion, the ACC lies in a middle layer, wrapping around the tough ‘heart’, or corpus callosum, which joins the two hemispheres. The ACC is also well-connected with many other parts of the brain controlling higher and lower functions with a role in integrating feelings with rational thinking.

The team started by measuring brain activity in rhesus macaques while they performed a task to select or reject a reward in the form of food combined with different levels of ‘punishment’ in the form of an annoying blast of air in the face. The potential choices were visually represented on a screen, and the monkeys used a joystick to make their selection, revealing how much discomfort they were willing to consider acceptable.

When the team probed the ACC of the monkeys, they identified groups of neurons that activated or deactivated in line with the sizes of the reward or punishment on offer. The neurons associated with avoidance and pessimistic decision-making were particularly concentrated in a part of the ACC called the pregenual ACC (pACC). This region has been previously linked to major depressive disorder and generalized anxiety disorder in humans.

Microstimulation of the pACC with a low-level electrical pulse caused the monkeys to avoid the reward, simulating the effects of anxiety. Remarkably, this artificially induced pessimism could be reversed by treatment with the antianxiety drug diazepam.

With knowledge of the pACC’s involvement in anxiety-related decision-making, the team next searched for its connections to other parts of the brain. They injected viruses at the specific sites that instructed nerve cells to start making fluorescent proteins that would light up under microscope observation. The virus then spread to other connected nerve cells, revealing the pathways other areas of the brain linked to this center of ‘pessimistic’ thought.

The team found interconnections with many parts of the prefrontal cortex at the front of the human brain, which is associated with higher cogitative function and reasoning. They also noted a strong connection with labyrinth-like structures known as striosomes.

Amemori explains, “The function of the striosome structure has been something of a mystery for a long time, but our experiments point to these being an important node linking pessimistic decision-making to the brain’s reward system and dopamine regulation.”

The team noted a further connection, namely that between these striosomes and another more distant region, the caudal region of the orbitofrontal cortex (cOFC) at the front of the brain. This part is also known to be involved in cognition and decision-making.  

When the team repeated their brain monitoring, microstimulation, and virus tracing studies in cOFC, they found a very similar influence on the monkey’s tendency toward pessimistic decision making. Curiously, the pACC and the cOFC also shared many of the same connections to other parts of the brain.

The team was able to generalize these findings in primates to humans by drawing comparisons with the body of knowledge in human brains studies based on magnetic resonance imaging or MRI.

Amemori says, “The many parallels in brain activation point to a common mechanism for both humans and monkeys. It’s important that we have associated striosomes and their extended network with decision making under an anxious condition, and we hope that this study will be useful toward developing brain pathway-specific treatments for neurological and psychiatric disorders in humans.”

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JOURNAL

Frontiers in Neuroscience

DOI

10.3389/fnins.2021.649167

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Causal evidence for induction of pessimistic decision-making in primates by the network of frontal cortex and striosomes

ARTICLE PUBLICATION DATE

29-Jun-2021

 

Transgender adults more likely to experience subjective cognitive decline, depression

Peer-Reviewed Publication

ALZHEIMER'S ASSOCIATION

 

IMAGE: ALZHEIMER'S ASSOCIATION INTERNATIONAL CONFERENCE 2021 view more 

CREDIT: ALZHEIMER'S ASSOCIATION

DENVER, JULY 28, 2021 -- Transgender and gender nonbinary adults in the U.S. are more likely to report worsening memory and thinking, functional limitations and depression compared to cisgender (non-transgender) adults, according to two studies reported at the Alzheimer's Association International Conference® (AAIC®) 2021 in Denver and virtually.

Little is known about Alzheimer's disease, dementia and cognitive impairment among transgender adults. However, it is known that transgender adults experience a greater number of health disparities considered risk factors for dementia -- including higher cardiovascular disease, depression, diabetes, tobacco/alcohol use and obesity -- and the social inequities experienced by transgender adults are also linked to an increased risk of cognitive impairment.

One of the first clinical manifestations of Alzheimer's disease may be subjective cognitive decline (SCD), a self-reported experience of confusion or memory loss that is happening more often or is getting worse.

These new data at AAIC 2021 are among the first ever looking at cognition specifically in transgender and gender nonbinary individuals. Key findings include: - Transgender adults -- individuals who identify with a gender different than the one assigned to them at birth -- were nearly twice as likely to report SCD and more than twice as likely to report SCD-related functional limitations, such as reduced ability to work, volunteer or be social. - Prevalence of depression was significantly higher for transgender and gender nonbinary adults (individuals who identify outside the male/female binary) (37%) compared to cisgender adults (19.2%). Additionally, reports of cognitive disability, a surrogate for SCD, were significantly higher in transgender and nonbinary adults (24.7%) compared to cisgender adults (10.5%).

"We know far too little about Alzheimer's, dementia and cognitive well-being among transgender and gender nonbinary individuals," said Carl V. Hill, Ph.D., MPH, Alzheimer's Association chief diversity, equity and inclusion officer. "As we learn more about dementia within this population, there is a great need for health care that is culturally competent and delivered with humility to address the needs of aging transgender individuals and their loved ones."

The first dementia prevalence data for U.S. lesbian, gay and bisexual individuals were reported at AAIC 2018, followed by the first data report suggesting higher rates of SCD among lesbian, gay, bisexual and/or transgender Americans at AAIC 2019. Also that year, the Alzheimer's Association partnered with SAGE (Advocacy & Services for LGBT Elders) to develop an issues brief and infographic that offers recommendations for working with LGBT people living with Alzheimer's or other dementias, as well as supporting LGBT-identified caregivers for people living with dementia. Among those recommendations is using gender-affirming language. The Association also maintains a list of resources for the LGBT community and caregivers on its website.

Transgender Adults Report More Subjective Cognitive Decline Than Cisgender Adults

Using data from the 2015-2019 Behavioral Risk Factor Surveillance System (BRFSS), a large annual health behavior survey led by the Centers for Disease Control and Prevention (CDC), Ethan Cicero, Ph.D., RN, Assistant Professor at Emory University's Nell Hodgson Woodruff School of Nursing, and colleagues examined data on SCD and associated functional limitations -- including giving up day-to-day activities or interferences with ability to work, volunteer or engage in social activities -- among transgender and cisgender adults.

Approximately 17% of transgender adults (1 in 6) reported SCD, which is significantly higher than the 10.6% rate for cisgender adults (roughly 1 in 10). Among those reporting SCD, transgender adults were 2.3 times more likely to report associated social and self-care limitations when compared to cisgender adults. Among those reporting SCD, transgender adults were about three years younger and more likely to be a racial/ethnic minority, to be uninsured, and to have depression.

Barriers to health care were a concern among transgender adults -- 1 in 3 transgender adults who experienced worsening memory problems and 1 in 2 transgender adults with related social and self-care limitations were unable to see a doctor because of cost.

"We are not certain what may be causing the elevated subjective cognitive decline rates among transgender adults. We postulate that it may be in part due to anti-transgender stigma and prejudice that expose transgender people to high rates of mistreatment and discrimination where they live, work, learn, seek health care and age," Cicero said. "More research is needed to identify and target preventive intervention strategies, develop culturally relevant screenings, and shape policies to improve the health and well-being of the transgender population."

Depression, Cognitive Disability Higher Among Transgender and Gender Nonbinary Adults

Using data from the 2019 BRFSS, Nickolas H. Lambrou, Ph.D., assistant scientist, Gleason Lab at the Division of Geriatrics and Gerontology at the University of Wisconsin School of Medicine & Public Health, and colleagues examined associations between health conditions, cognitive disability and gender identity. Of respondents providing a gender identity (n=231,414), 955 identified as transgender or gender nonbinary (TNB).

The researchers found prevalence of depression was significantly higher for transgender and nonbinary adults (37%) compared to cisgender adults (19.2%). Additionally, reports of cognitive disability were significantly higher in TNB respondents (24.7%) compared to cisgender respondents (10.5%). Nonbinary respondents reported the highest proportion of depression (49.6%) and cognitive disability (30.5%) compared to all other gender groups. The analysis also suggested that men, whether transgender or cisgender, were more likely to report cognitive disability associated with depression compared to other groups. However, it is important to note that cisgender men also reported the lowest proportions of depression (14%) and cognitive disability (9.4%) compared to all other gender identity groups.

"This research demonstrates that the cognitive health of transgender or gender nonbinary adults is different than cisgender adults, and that there are health differences within the TNB population. Notably, TNB respondents reported depression and cognitive disability at more than twice the rate of cisgender adults," Lambrou said.

"These rates are concerning because cognitive disability may be a risk factor or early indicator of Alzheimer's or other dementia. Further research is needed; it is critical that researchers include measures to identify TNB participants so we have an accurate representation of their health and health behaviors," Lambrou added.

 AMERICAN GUN CULTURE POST SHOOTING PTSD

Nonfatal firearm injuries lead to increased chance of mental health disorder in youth

Researchers at MUSC Health find those under 18 years of age are more likely to suffer a mental health disorder in the year following a nonfatal firearm injury

Peer-Reviewed Publication

MEDICAL UNIVERSITY OF SOUTH CAROLINA

THIS RESEARCH TEAM FOUND THAT CHILDREN WITH AN UNDERLYING MENTAL ILLNESS ALREADY HAVE A HIGHER BASELINE RISK FOR INJURY FROM A FIREARM. AND ONCE INJURED, THE SAME CHILDREN HAVE A GREATER RISK OF DEVELOPING ADDITIONAL MENTAL DISORDERS. view more 

CREDIT: BRENNAN WESLEY, MUSC HEALTH

For every youth who dies with injury from a firearm, at least four survive. These survivors led researchers at MUSC Health to look at new mental health diagnoses that may stem from nonfatal gunshot wounds in adolescents. 

Betsy Oddo, M.D., a pediatric hospital medicine fellow at MUSC Shawn Jenkins Children’s Hospital, says firearm injury is the leading cause of death for youth in the United States. In a recent paper in Academic Pediatrics, Oddo and her team looked at pediatric patients in the year before they suffered their firearm-related injury and the year following.

“What we ultimately found is that in the time before their injury, a large proportion of these patients already had an underlying mental health diagnosis,” she said. “And then in the year after their injuries, another proportion went on to have a new mental health diagnosis.” 

This research team found that children with an underlying mental illness already have a higher baseline risk for injury from a firearm. And once injured, the same children have a greater risk of developing additional mental disorders. Any physical disability they may experience from the injury adds to any mental stress they may also be feeling. 

The level of risk depends on the type of mental health disorder prior to injury. Children diagnosed with depression are at a higher risk for suicide, and according to the Centers for Disease Control and Prevention, 3.2% of children between the ages of 3 and 17 have diagnosed depression ­— which equates to 1.9 million people in the United States. Rates of depression in children have only increased over time.

Oddo points to conduct disorder as another risk factor, as children with conduct disorders or substance-related disorders are more likely to be involved in community violence. While more common in boys than in girls, the lifetime prevalence of conduct disorder is 12% for boys and 7% for girls according to American Family Medicine.

Patients in South Carolina have access to the MUSC Health Trauma Survivors Network, which provides a community of patients, families, health care providers and volunteers who can help people connect after a serious injury such as a gunshot wound. In addition to connecting trauma victims with mental health services when they are first admitted to the hospital, Oddo is also part of a hospital-based violence intervention program that will soon start to see children. 

Physicians at MUSC also screen children who enter the hospital or emergency room with mental health concerns as well as asking about any firearms at home. If there are firearms in the home, Oddo can offer free gun locks to the family and free counseling on safe gun storage as an injury prevention method. She thinks discussing access to firearms should be a regular part of any pediatrician visit.

“This paper just goes to show that the mental health epidemic in this country and the firearm violence epidemic in this country are intertwined,” said Oddo. “It’s important for us to address mental health needs in the population of children who have suffered a firearm injury.”

Oddo and her team plan to look at the ways these children are utilizing the mental health care system in an effort to understand if they are getting adequate attention in the timeframe needed following a firearm-related injury. She advises any parents who are concerned about mental health disorders in their children to be mindful of guns in their homes, urging parents to keep weapons locked away and to keep firearms separate from ammunition to reduce the odds of the physical injury and mental health damage that a firearm injury can inflict. 

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As the clinical health system of the Medical University of South Carolina, MUSC Health is dedicated to delivering the highest quality patient care available while training generations of competent, compassionate health care providers to serve the people of South Carolina and beyond. Comprising some 1,600 beds, more than 100 outreach sites, the MUSC College of Medicine, the physicians’ practice plan and nearly 275 telehealth locations, MUSC Health owns and operates eight hospitals situated in Charleston, Chester, Florence, Lancaster and Marion counties. In 2020, for the sixth consecutive year, U.S. News & World Report named MUSC Health the No. 1 hospital in South Carolina. To learn more about clinical patient services, visit muschealth.org.

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JOURNAL

Academic Pediatrics

DOI

10.1016/j.acap.2021.06.003

ARTICLE TITLE

Increase in Mental Health Diagnoses Among Youth With Nonfatal Firearm Injuries

ARTICLE PUBLICATION DATE

10-Jun-2021

Using AI to predict suicidal behaviours in students

Algorithm shows self-esteem is one of four major predictors of suicidal behaviours

Peer-Reviewed Publication

MCGILL UNIVERSITY

How can we predict suicide risk in students, especially at a time when the COVID-19 pandemic has negatively affected many people’s mental health? According to researchers from Montreal and France, self-esteem represents an important predictive marker of suicidal risk. The team from McGill University, University of Montreal, Inserm, and Université de Bordeaux is using artificial intelligence to identify factors that accurately predict suicidal behavior in students.

“Suicide is the second leading cause of death among 15- to 24-year-olds. Early detection of suicidal behaviours and thoughts is the key to providing appropriate treatment,” says lead author Mélissa Macalli, a PhD Candidate at University of Bordeaux.

Published in Scientific Reports, their analysis is based on data collected from over 5,000 university students in France who were followed for at least one year between 2013 and 2019. The study shows that out of 70 potential predictors, four detect around 80 percent of suicidal behaviours at follow-up. These are suicidal thoughts, anxiety, depressive symptoms, and self-esteem.

AI identifies main predictors of suicidal behaviours

Using machine learning, the researchers simultaneously analyzed the many factors associated with suicidal risk and ranked them according to their importance in predicting suicidal behaviours. These factors included sociodemographic data, lifestyle, substance use, childhood trauma, and personal and family history of suicidal behaviours.

“Many known factors can contribute to the increased risk in university students, such as the transition from high school to college, psychosocial stress, academic pressures, and adapting to a new environment. These are risks that have also been exacerbated by the health crisis triggered by the COVID-19 pandemic, although there is no clear evidence of an increase in suicide rates during the pandemic,” says co-author Massimiliano Orri, a Postdoctoral Fellow at McGill University with the McGill Group for Suicide Studies and at University of Bordeaux.

Opening the door to large scale screening

The students completed two surveys, one at the time of enrollment in the study and the other a year later, providing researchers with critical information about their health, drug and alcohol use, medical and psychiatric history, and their psychological state. This follow-up survey revealed that approximately 17 percent of the participating students, both women (17.4 percent) and men (16.8 percent), exhibited suicidal behaviours in the year elapsing between the two questionnaires.

“This research opens up the possibility of large-scale screening by identifying students at risk of suicide using short, simple questionnaires, in order to refer them to appropriate care,” explains senior author Christophe Tzourio, a Professor of epidemiology at Université de Bordeaux and Director of the Bordeaux Population Health research center. Such screening tools could provide an alternative to mental health assessments by a physician for students who are often reluctant to disclose sensitive personal information in face-to-face interactions.

Self-esteem: a previously unrecognized predictor

According to the researchers, self-esteem represents an important predictive marker of suicidal risk and should therefore be used in screening tools, even among students that do not show signs of suicidal behaviours.

In secondary analyses of 3,946 students that did not exhibit suicidal behaviours, the primary predictors that stood out for men was self-esteem. For women, they were self-esteem, depressive symptoms, and academic stress.

Low self-esteem is known to be a part of social anxiety, and to overlap with depression. Self-esteem, which is an important marker of psychological vulnerability in young adults has also been associated with suicidal thoughts. “Our study showed that self-esteem is an independent and prominent predictive marker,” say the researchers.

“The mental health specialists on our teams did not expect self-esteem to be one of the top four predictors of suicidal behaviours,” says Mélissa Macalli. “This finding would not have been discovered without the use of machine learning, which makes it possible to analyze a large amount of data simultaneously. This opens up new avenues for both research and prevention,” she concludes.

THE IRONY IS THAT SCHOOL REFORM FROM THE RIGHT 

DECRIES SELF ESTEEM AS A LIBERAL CULTURAL 

BUG A BOO

About this study

“A machine learning approach for predicting suicidal thoughts and behaviours among college students” by Mélissa Macalli, Marie Navarro, Massimiliano Orri, Marie Tournier, Rodolphe Thiébaut, Sylvana M. Côté and Christophe Tzourio was published in Scientific Reports.

DOI: https://doi.org/10.1038/s41598-021-90728-z

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-021-90728-z

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

A machine learning approach for predicting suicidal thoughts and behaviours among college students

ARTICLE PUBLICATION DATE

15-Jun-2021

 

Early adulthood education and employment experiences play independent role in later life cardiovascular health

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

New research published today in the Journal of Epidemiology and Community Health has found that education and employment experiences in early adulthood contribute to cardiovascular health inequalities in later life, independent of occupation and family income in mid-adulthood.

There are important differences in health between different sectors of our society, with those who are less educated and in lower status jobs shown to be less healthy and have shorter life expectancy on average than the more privileged.  While early adulthood is an important time for both the development of adult socioeconomic position and for development of behaviours related to cardiovascular health, until now the degree to which early adulthood socioeconomic trajectories contribute directly to health differences observed in later life has not been clear.

Researchers from the University of Cambridge, University of Bristol and UCL Social Research Institute analysed health and socioeconomic data collected over several decades from over 12,000 members of the 1970 British Birth Cohort, to determine the contribution of early adulthood to differences in cardiovascular health in mid-adulthood. The scientists used a data-driven method to divide the population into different socioeconomic trajectory groups based on their participation in education, different job types, unemployment or economic inactivity across early adulthood (ages 16-24). They studied the association of these groups with cardiovascular risk factors at age 46, including blood pressure, cholesterol levels, waist circumference. To determine if the association of early adulthood socioeconomic trajectories with cardiovascular health was mediated by socioeconomic status later in life, they examined how correcting for occupation or family income at age 46 affected the link.

Professor Kate Tilling from the MRC Integrative Epidemiology Unit at the University of Bristol, and senior author on the paper, said: “Measuring socioeconomic position in early adulthood has always been difficult as this is a period of transition when most people’s occupations change over time. The method we’ve developed provides a flexible way to identify early adulthood socioeconomic position, and we hope that it will be used in future to answer other research questions related to this period of life.”

The researchers found that those who spent a longer time in education, going on to employment in professional or managerial roles during early adulthood, had better cardiovascular health more than 20 years later (at age 46) than other groups. Importantly this association wasn’t entirely because of a higher income or higher level job at age 46, suggesting an independent and long-term association of early adulthood influences with health.

The findings indicate that that material factors in mid-adulthood do not contribute to the pathway through which early adulthood socioeconomic trajectory affects mid-life health, and the authors suggest that the development of health behaviours or psychosocial factors such as stress, depression, and job control in early adulthood may play an important role.

Dr Eleanor Winpenny from the MRC Epidemiology Unit at the University of Cambridge, and first author on the paper, said:

“We found that an individual’s education and employment experiences in early adulthood had a far larger impact on measures of cardiovascular health more than twenty years later than their occupation or income at that time did.

These results suggest that we need to provide more support for young adults to allow healthy development into middle age and prevent disease in later life. Given the added disadvantage to young adults as a result the current coronavirus pandemic, there is an urgent need to understand and mitigate the effect these circumstances may be having on their future health”.

The research was funded by the Medical Research Council and the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and Wellcome, under the auspices of the UK Clinical Research Collaboration.

Reference

Winpenny, E. et al. Early adulthood socioeconomic trajectories contribute to inequalities in adult cardiovascular health, independently of childhood and adulthood socioeconomic position. Journal of Epidemiology and Community Health 2021; 6 Aug 2021; DOI: 10.1136/jech-2021-216611

After publication the paper will be available at http://dx.doi.org/10.1136/jech-2021-216611

ENDS

 

About the MRC Epidemiology Unit

The MRC Epidemiology Unit is a department at the University of Cambridge. It is working to improve the health of people in the UK and around the world.  Obesity, type 2 diabetes and related metabolic disorders present a major and growing global public health challenge. These disorders result from a complex interplay between genetic, developmental, behavioural and environmental factors that operate throughout life. The mission of the Unit is to investigate the individual and combined effects of these factors and to develop and evaluate strategies to prevent these diseases and their consequences. www.mrc-epid.cam.ac.uk

 

About the University of Cambridge

The University of Cambridge is one of the world’s top ten leading universities, with a rich history of radical thinking dating back to 1209. Its mission is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.

The University comprises 31 autonomous Colleges and 150 departments, faculties and institutions. Its 24,450 student body includes more than 9,000 international students from 147 countries. In 2020, 70.6% of its new undergraduate students were from state schools and 21.6% from economically disadvantaged areas.

Cambridge research spans almost every discipline, from science, technology, engineering and medicine through to the arts, humanities and social sciences, with multi-disciplinary teams working to address major global challenges. Its researchers provide academic leadership, develop strategic partnerships and collaborate with colleagues worldwide.

The University sits at the heart of the ‘Cambridge cluster’, in which more than 5,300 knowledge-intensive firms employ more than 67,000 people and generate £18 billion in turnover. Cambridge has the highest number of patent applications per 100,000 residents in the UK.

www.cam.ac.uk

 

About the MRC IEU
The MRC Integrative Epidemiology Unit (IEU) at the University of Bristol conducts some of the UK's most advanced population health science research. It uses genetics, population data and experimental interventions to look for the underlying causes of chronic disease. The unit exploits the latest advances in genetic and epigenetic technologies. We develop new analysis methods to improve understanding of how our family background, behaviours and genes work together. Using these to investigate how people develop and remain healthy or become ill. www.bristol.ac.uk/integrative-epidemiology/

 

About the Medical Research Council

The Medical Research Council is at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers’ money in some of the best medical research in the world across every area of health. Thirty-three MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. The Medical Research Council is part of UK Research and Innovation. https://mrc.ukri.org/

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DOI

10.1136/jech-2021-216611

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Early adulthood socioeconomic trajectories contribute to inequalities in adult cardiovascular health, independently of childhood and adulthood socioeconomic position.

ARTICLE PUBLICATION DATE

5-Aug-2021

COI STATEMENT

None declared

 

Chasing the light from elusive ‘milky seas’: CSU researchers light a path toward unraveling mysteries of the ocean from space

Peer-Reviewed Publication

COLORADO STATE UNIVERSITY

 

IMAGE: A COMPARISON OF PHOTOS TAKEN BY OLDER SATELLITE INSTRUMENTS (LEFT) WITH IMAGERY FROM THE NEW DAY-NIGHT BAND (DNB) INSTRUMENT (RIGHT). view more 

CREDIT: CSU/CIRA AND NOAA/NESDIS

Using nearly a decade of satellite data, researchers at Colorado State University have uncovered “milky seas” in a way they’ve never been seen before – a rare and fascinating oceanic bioluminescent phenomenon detected by a highly sensitive spaceborne low-light sensor.

The watershed study appears in the world’s largest scientific journal, Scientific Reports, published by Nature Research.

Milky seas are an elusive and rare display of bioluminescence in the Earth’s ocean, and the largest known form on our planet. Distinct from turbulent froth created by wakes of ships, milky seas achieve a long-lived, widespread, and uniform glow in the ocean’s surface that can persist for several nights, and span more than 100,000 square kilometers (almost 39,000 square miles) – about the size of the state of Kentucky.

Mariners experience these extraordinary conditions only in certain remote areas of the world—mainly in the northwest Indian Ocean offshore of the Horn of Africa, and in the waters surrounding Indonesia. Predicting when, where, and why milky seas form remains a modern-day scientific mystery.

The mysterious glow

Surreal descriptions of the fabled “milky sea,” which eyewitnesses say glows as bright as a snow field or a bed of clouds, has been shared among mariners throughout history, said Steve Miller, CIRA’s incoming director and lead author on the Scientific Reports paper. These stories found their way into seafaring adventure novels like Moby-Dick  and Twenty Thousand Leagues Under the Sea, taking their place in folklore, but not so much in scientific observation.

In more than 200 recorded sightings dating back to the 19th century, only once, in 1985, did a research vessel sail through a milky sea. The water sample collected at the time suggested a strain of luminous bacteria, colonizing a bloom of algae at the water’s surface, created the glow. Some of the features of milky seas, however, are not adequately explained by this hypothesis – especially in the face of eyewitness accounts.

Bolstered by new observations from space, researchers are now positioned to understand much more about the circumstances of this fascinating phenomenon. From far above the world’s oceans, the Suomi NPP and NOAA-20 satellites collect imagery using a sophisticated suite of sensors, including the “Day/Night Band” instrument. The Day/Night Band detects very faint amounts of visible light at night, and peers through the darkness to reveal the glow of city lights, the flames of forest fires, and much more – including, now, the ability to see milky seas.

At CSU’s Cooperative Institute for Research in the Atmosphere (CIRA), researchers are constantly analyzing satellite data, including observations from the Day/Night Band. CIRA research using this instrument targeted changing city lights to demonstrate how the COVID-19 pandemic impacted human activity. Researchers have also used it to discover a new phenomenon of nighttime glowing in the Earth’s atmosphere.

“The Day/Night Band continues to amaze me with its ability to reveal light features of the night. Like Captain Ahab of Moby-Dick, the pursuit of these bioluminescent milky seas has been my personal ‘white whale’ of sorts for many years,” Miller said.

Catching the light

By carefully analyzing Day/Night Band observations from three locations where milky seas are often reported, Miller and his team located 12 occurrences of this elusive phenomenon between 2012 and 2021.

Catching the light created by milky seas requires patience – and the right conditions. Even faint moonlight reflecting off the ocean’s surface can mask the signal. Light emitted by the glowing upper atmosphere, both directly upward and as reflected by the clouds, can likewise contaminate observations. Researchers carefully analyzed signals in the satellite data to rule out other sources of light emission, and used sophisticated techniques to find the persistent bioluminescent structures emitting light beyond the background noise.

Appearing as a persistent glowing patch on the ocean at night, these glowing bodies of water move with ocean currents. Disappearing from view during the day – due to the overwhelming amount of light from the Sun compared to the faint glow from the ocean – these patches become visible again to the satellite.

Coupling the satellite observations with measures of sea surface temperature, marine biomass, and the analyzed sea surface currents have led the authors to pose new hypotheses for the unique conditions surrounding milky sea formation.

“Milky seas are simply marvelous expressions of our biosphere whose significance in nature we have not yet fathomed,” Miller said. “Their very being spins an unlikely and compelling tale that ties the surface to the skies, the microscopic to the global scales, and the human experience and technology across the ages; from merchant ships of the 18th century to spaceships of the modern day. The Day/Night Band has lit yet another pathway to scientific discovery.”

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Imagery and data from this research, including a supplemental collection of colorful eyewitness accounts from mariner encounters with milky seas over the years, are all available online.

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-021-94823-z

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Honing in on bioluminescent milky seas from space

ARTICLE PUBLICATION DATE

29-Jul-2021

Sea Fever

John Masefield

I must go down to the seas again, to the lonely sea and the sky,

And all I ask is a tall ship and a star to steer her by,

And the wheel's kick and the wind's song and the white sail's shaking,

And a grey mist on the sea's face, and a grey dawn breaking,

 

I must down to the seas again, for the call of the running tide

Is a wild call and a clear call that may not be denied; 

And all I ask is a windy day with the white clouds flying,

And the flung spray and the blown spume, and the sea-gulls crying.

 

I must down to the seas again, to the vagrant gypsy life,

To the gull's way and the whale's way where the wind's like a whetted knife;

And all I ask is a merry yarn from a laughing fellow-rover,

And quiet sleep and a sweet dream when the long trick's over.

 

Nitrogen inputs in the ancient ocean

Underappreciated bacteria step into the spotlight

Peer-Reviewed Publication

MAX-PLANCK-GESELLSCHAFT

 

IMAGE: PURPLE SULFUR BACTERIA IN FRESHWATER LAKE CADAGNO (UPPER PANELS, IN GREEN AND PURPLE), AND THEIR SINGLE-CELL NITROGEN FIXATION ACTIVITY MEASURED WITH NANOSIMS (LOWER PANELS, WARM COLORS INDICATE HIGH ACTIVITY). view more 

CREDIT: MAX PLANCK INSTITUTE FOR MARINE MICROBIOLOGY/M. PHILIPPI

Nitrogen is vital for all forms of life¬: It is part of proteins, nucleic acids and other cell structures. Thus, it was of great importance for the development of life on early Earth to be able to convert gaseous dinitrogen from the atmosphere into a bio-available form – ammonium. However, it has not yet been clarified who carried out this so-called nitrogen fixation on early Earth and with the help of which enzyme. Now, researchers at the Max Planck Institute for Marine Microbiology in Bremen have shown that under similarly barren conditions as in the Proterozoic ocean, a previously underappreciated group of bacteria can fix nitrogen very efficiently.

A “small Proterozoic ocean” in the Swiss Alps

Since the Proterozoic ocean can hardly be studied directly, the researchers Miriam Philippi and Katharina Kitzinger from the Max Planck Institute in Bremen and colleagues substituted it with a comparable modern-day habitat: The alpine Lake Cadagno in Switzerland. Unlike most other lakes, Lake Cadagno is permanently stratified, meaning that the upper and lower water layers do not mix. Purple sulfur bacteria inhabit the transition zone between the upper, oxygenated layer and the lower, oxygen-free and sulfidic layer. There, they carry out photosynthesis and oxidize sulfur. “The discovery of fossils of this group of microorganisms shows that they already lived on our planet at least 1.6 billion years ago, during the Proterozoic eon,” said Philippi, first author of the study. “Hence, this lake and these bacteria represent a system that resembles the Proterozoic ocean in many aspects.” Therefore, it is so well-suited for learning more about the processes on early Earth.

Purple sulfur bacteria fix nitrogen

Using a combination of biogeochemical and molecular analyses, Philippi and colleagues discovered that the purple sulfur bacteria in Lake Cadagno fix nitrogen very efficiently. Nitrogen fixation is the conversion of nitrogen gas, which is not very reactive, into nitrogen compounds that many organisms can use, for example algae. “To our knowledge, this is the first direct evidence of nitrogen fixation by purple sulfur bacteria in nature,” explained co-author Katharina Kitzinger. “We discovered that they use the most common enzyme in present-day, molybdenum nitrogenase, to do so. Although this enzyme is not rare, we were very surprised to find it in Lake Cadagno.” This is because there is only very little molybdenum in the water – just as in the Proterozoic ocean, which has led researchers to believe that non-molybdenum nitrogenases prevailed on early Earth. “Now we know that molybdenum nitrogenase works very efficiently, even at low molybdenum concentrations.”

“We thus provide the first indication that purple sulfur bacteria may have been partly responsible for nitrogen fixation in the Proterozoic ocean,” Philippi continued. “Until now, it was generally assumed that cyanobacteria carried out most of the nitrogen fixation then. We show that the role of purple sulfur bacteria in this process was likely underestimated.”

  

CAPTION

Salty springs at the lake bottom prevent mixing, resulting in a stable stratification. The upper meters contain oxygen but little nutrients. The lower layer is anoxic and rich in sulfide, creating a stable intermediate layer with steep concentration gradients of oxygen and sulfide. Here, the purple sulfur bacteria use solar energy to oxidize sulfide – and fix nitrogen.

CREDIT

Miriam Philippi

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JOURNAL

Nature Communications

ARTICLE TITLE

Purple sulfur bacteria fix N2 via molybdenum-nitrogenase in a low molybdenum Proterozoic ocean analogue.

ARTICLE PUBLICATION DATE

5-Aug-2021