British sex lives revealed in new study

Peer-Reviewed Publication

UNIVERSITY OF EAST ANGLIA

A new study published today shows the number of sexual partners we have changes as we age – and there are some surprising results. 

Researchers from the University of East Anglia (UEA), in collaboration with King’s College London and University College London, surveyed more than 5,000 people aged 18 years and older during the 2022 mpox (previously known as “monkeypox”) outbreak.  

The team wanted to better understand how sexual behaviours change with age, so that mathematical models of sexually transmitted infections can be made more accurate. Key findings included in the paper, published today in the journal PLOS ONE, show that many gay and bisexual men over age 70 continue to have a sex life with multiple partners, while straight women become less sexually active after age 50. 

Lead researcher Dr Julii Brainard, from UEA’s Norwich Medical School, said: “Before this study, many models about sexually transmitted diseases assumed that everyone over a certain age - say 40 or 65 - stopped being sexually active, or at least stopped having multiple partners.   

“Or there might be an assumption that young people have the most sex. But the answer is more nuanced, and it partly depends on people’s sexuality.” 

The study is based on a survey of 5164 British people, including 3297 sampled from the general population and 1036 men who have sex with men (MSM) recruited via Facebook and Instagram. A further 831 people responded to adverts on the gay dating app Grindr.  
 
“The 2022 mpox cases spread mostly among men who have sex with men, so we particularly surveyed this group,” explained Dr Brainard. 

The participants were asked for their gender, sexual identity (gay, bisexual or heterosexual) and how many sexual partners they had had in the last three weeks and in the last three months. The answers were divided into the three largest groups that each had more than a thousand responses: women who have sex with men, men who have sex with women, and men who have sex with men. 

The team focused on the relationship between sex partner counts in last three weeks and respondent age, using statistical models to see how much a person's age was linked to their recent partner count. 

Key findings: 

•    Most people surveyed had either zero or one sexual partner at any age in the preceding three weeks. 

•    About 65 per cent of heterosexual women reported having one partner in the last three weeks consistently until they were 50 - after which there was a steep climb in reporting no partners. 79 per cent of women age 70+ who identified as heterosexual or had any male partners in last 3 months, had had no male partners in the last three weeks.
 
•    Of the heterosexual men surveyed (all age groups), 50 per cent reported having one partner in the last three weeks. But they were increasingly likely to report no partners as they got older. 50 per cent of men age 70+ who were heterosexual or had had sex with any women in last three months, didn’t have a female partner in the most recent three weeks, compared to just 44 per cent of men having heterosexual sex who had no recent female partners when age under 70.  

•    Partner concurrency – which is more than one recent sex partner – was uncommon in the general population, but common among the social media samples. 42 per cent of MSMs recruited on Facebook or Instagram and 52 per cent of Grindr respondents had at least two recent male partners.  

•    Partner concurrency declined among older people, with least decline among social media respondents. Seventy-seven men who have sex with men, age 70+, answered the survey. 17 per cent of them reported more than one recent partner in the most recent three weeks. 25 per cent of the MSM age 70+ recruited via social media had concurrent partners. 

•    Only two per cent of straight people over 70 reported multiple partners. 

Dr Brainard said: “Most people in our survey, regardless of their gender identity or sexuality, had zero or one recent partner at any age.   

“We managed to collect a lot of data from MSM who practiced partner concurrency. About 45 per cent of them sustained partner concurrency from age 27 to 63. Even at age 65+ the respondents recruited via social media still tended to have more sexual contact than the general population sample at the same age.    

“It would be interesting to see if these findings were replicated if we targeted heterosexuals most likely to practice partner concurrency. 

“Models of disease spread shouldn't assume that young people are necessarily most at risk or that having multiple partners just stops happening at a strict age threshold.” 

The information about age profiles and sexual habits is useful because it helps to tailor safe sex messages at the right demographics and using media channels that best reaches these subgroups. 
Research Fellow Dr Louise Smith at Kings College London coordinated the survey in autumn 2022 to collect information about public awareness of mpox and what public health messages might be most motivating for different sub-groups. 

Dr Smith said: “This study underscores the importance of considering how data were collected. For instance, we can’t conclude from this survey that MSM who use social media are particularly likely to have concurrent partners. But it may be that the algorithms that Facebook or Instagram use to identify MSMs are also very good at finding that subset of people. 

“At the time, mpox mostly affected gay and bisexual men so we focused recruitment on this group. Because we didn’t recruit very many lesbian and bisexual women, or members of the trans community, our statistical analyses would have been less reliable for these groups.  

“Further research into other minority sexualities and gender identities could be beneficial to better understand the granularity of sexual behaviour and optimal public health messaging suited to different groups of people in the UK.” 

This work was funded by the National Institute for Health and Care Research. 

‘The relationship between age and sex partner counts during the mpox outbreak in the UK, 2022’ is published 8 September 2023 in the journal PLOS ONE. 
 

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JOURNAL

PLoS ONE

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The relationship between age and sex partner counts during the mpox outbreak in the UK, 2022

ARTICLE PUBLICATION DATE

8-Sep-2023

 

Synchrotron studies change the composition of the Earth’s core

Peer-Reviewed Publication

RIKEN

In work published in Science Advances, a team of researchers have determined a new pressure scale, which is critical for understanding the Earth’s composition. Using x-rays from a uniquely powerful spectrometer at RIKEN’s SPring-8 Center they avoided some of the large approximations of previous work, discovering that the previous scale overestimated pressure by more than 20% at 230 gigapascals (2.3 million atmospheres) - a pressure reached in Earth’s core. This is similar to someone running a marathon that they thought was 42 kilometers, but finding they had only really run 34 kilometers. While 20% might seem like a modest correction, it has big implications. 

An accurate pressure scale is critical for understanding the composition of the Earth. In particular, the core composition is hotly debated as it is important both for understanding our planet at present, and for understanding the evolution of the solar system in the distant past. While it is generally accepted that the core is mostly iron, evidence from tracking the propagation of seismic waves from earthquakes suggests the core also contains lighter material. When the new scale was used to interpret the seismological model, the team found that the amount of light material in the inner core is about double what was previously expected, and indeed the total mass of light material in the entire core is probably five times, or more, that of the Earth’s crust – the layer that we live on. 

In the new work, the team, led by Alfred Q.R. Baron of the RIKEN SPring-8 Center, and Daijo Ikuta and Eiji Ohtani of Tohoku University, used Inelastic X-ray Scattering (IXS) to measure the sound velocity of a rhenium sample under pressure. A tiny rhenium sample (<0.000000001 grams = 1 nanogram) was put under extreme pressure by crushing it between two diamond crystals in a Diamond Anvil Cell (DAC). The cell was placed in the large IXS spectrometer at BL43LXU (figure 2) and small (~1 ppm) shifts in the energy of the x-rays scattered from the rhenium were carefully measured, allowing the researchers to determine the sound velocity of the rhenium. They determined both compressional/longitudinal and shear/transverse sound velocities, and the density of the rhenium. That allowed the researchers to determine the pressure that the rhenium was subjected to. 

The new study provides a direct relationship between rhenium density and pressure. Baron says, “The density of rhenium at high pressure is straightforward and fast to measure, and there are many facilities worldwide where such measurements can be made. However, measuring the sound velocity is much more difficult, and, at these pressures, is probably only practically possible using RIKEN’s spectrometer at BL43LXU of SPring-8.” The team has done the heavy lifting so that other scientists can now use a much easier-to-measure density to determine pressure. 

As Ikuta, Ohtani, and Baron say: “When we used our new scale to interpret the behavior of metallic iron under high pressure and compared it with the seismic model of the Earth, we found that the light material hidden in the inner core is probably about double what was previously expected. Similar changes, perhaps even larger in magnitude, may be expected in considering the structure of other planets. Our work also suggests reassessment of the pressure dependence of nearly all material properties that have been measured at pressures similar or larger than that of the Earth’s core.” 

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adh8706 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Density deficit of the Earth’s core revealed by a multi-megabar primary pressure scale

ARTICLE PUBLICATION DATE

8-Sep-2023

DRUIDIC STUDIES

How trees influence cloud formation

Peer-Reviewed Publication

PAUL SCHERRER INSTITUTE

 

IMAGE: IN THE LABORATORY FOR ATMOSPHERIC CHEMISTRY, LUBNA DADA INVESTIGATES THE FORMATION AND CHEMICAL COMPOSITION OF AEROSOLS, AMONG OTHER THINGS. view more 

CREDIT: PAUL SCHERRER INSTITUTE/ MARKUS FISCHER

As part of the international CLOUD project at the nuclear research centre CERN, researchers at PSI have identified so-called sesquiterpenes – gaseous hydrocarbons that are released by plants – as being a major factor in cloud formation. This finding could reduce uncertainties in climate models and help make more accurate predictions. The study has now been published in the journal Science Advances.

According to the latest projections of the Intergovernmental Panel on Climate Change (IPCC), the global climate will be 1.5 to 4.4 degrees Celsius warmer than pre-industrial levels by 2100. This figure is based on various scenarios describing how anthropogenic greenhouse gas emissions may develop in the future. So in the best case, if we manage to curb emissions quickly and radically, we can still meet the 1.5 degree target of the Paris Agreement. In the worst case, we will end up far above that. However, such projections are also subject to some uncertainty. In the worst-case scenario, for example, with emissions continuing to increase sharply, the rise in temperature could be as low as 3.3 or as high as 5.7 degrees Celsius, rather than 4.4 degrees.

These uncertainties in predicting how temperatures will change as a result of concrete developments in greenhouse gas emissions are essentially due to the fact that scientists do not yet fully understand all the processes that occur in the atmosphere – the interactions between the various gases and aerosols in it. Establishing them is the aim of the CLOUD project (Cosmics Leaving Outdoor Droplets), an international collaboration between atmospheric researchers at the CERN nuclear research centre in Geneva. PSI helped to build the CLOUD chamber and is a member of the project’s steering committee.

The mystery of cloud formation

Particularly the way in which cloud cover will develop in the future remains largely nebulous for the time being. However, this is a key factor in predicting the climate because more clouds reflect more solar radiation, thus cooling the earth’s surface.

To form the droplets that make up clouds, water vapour needs condensation nuclei, solid or liquid particles on which to condense. These are provided by a wide variety of aerosols, tiny solid or liquid particles between 0.1 and 10 micrometres in diameter, which are produced and released into the air both by nature and by human activity. These particles can include salt from the sea, sand from the desert, pollutants from industry and traffic, or soot particles from fires, for example. However, about half the condensation nuclei are actually formed in the air when different gaseous molecules combine and turn into solids, a phenomenon that experts call “nucleation” or “new particle formation” (NPF). To begin with, such particles are tiny, barely larger than a few nanometres, but over time they can grow through the condensation of gaseous molecules and then serve as condensation nuclei.

Greenhouse gases that you can smell

The main anthropogenic gas that contributes to the formation of particles is sulphur dioxide in the form of sulphuric acid, mainly from burning coal and oil. The most important natural gases involved are so-called isoprenes, monoterpenes and sesquiterpenes. These are hydrocarbons that are mainly released by the vegetation. They are key components of the essential oils that we smell when, for example, grass is cut or we go for a walk in the woods. When these substances oxidise, i.e. react with ozone, in the air they form aerosols.

“It should be noted that the concentration of sulphur dioxide in the air has decreased significantly in recent years due to stricter environmental legislation and it will continue to decrease,” says Lubna Dada, an atmospheric scientist at PSI. “The concentration of terpenes, on the other hand, is increasing because plants release more of them when they experience stress – for example when there is an increase in temperatures and extreme weather conditions and vegetation is more frequently exposed to droughts.” The big question for improving climate predictions is therefore which of the factors will predominate, leading to an increase or a decrease in cloud formation. To answer this, one would need to know how each of these substances contributes to the formation of new particles. A great deal is already known about sulphuric acid, and the role of monoterpenes and isoprene is now also understood better thanks to measurements in the field and chamber experiments like CLOUD, in which PSI has been involved.

Sesquiterpenes are rare but effective

Until now, sesquiterpenes have not been a focus of research. “This is because they are quite difficult to measure,” explains Dada. “Firstly because they react very quickly with ozone, and secondly because they occur much less frequently than the other substances.” Around 465 million tonnes of isoprene and 91 million tonnes of monoterpenes are released every year, whereas sesquiterpenes account for just 24 million tonnes. Nevertheless, the new study, of which Dada is the lead author, has shown that these compounds play an important role in cloud formation. According to the measurements, they form ten times more particles than the other two organic substances at the same concentration.

To determine this, Dada and her coauthors used the unique CLOUD chamber at the European Organisation for Nuclear Research, CERN. The chamber is a sealed room in which different atmospheric conditions can be simulated. “At almost 30 cubic metres, this climate chamber is the purest of its kind worldwide,” says Dada. “So pure that it allows us to study sesquiterpenes even at the low concentrations recorded in the atmosphere.”

This was precisely what the study set out to do. It was designed to simulate biogenic particle formation in the atmosphere. More specifically, researchers were interested in studying pre-industrial times, when there were no anthropogenic sulphur dioxide emissions. This allows the effect of human activities to be determined more clearly and projected into the future. However, anthropogenic sulphur dioxide has long since become ubiquitous in nature. This is another reason why only the CLOUD chamber was viable. It also allows a pre-industrial mixture to be produced under controlled conditions.

Persistent particles lead to more clouds

The experiments revealed that the oxidation of a natural mixture of isoprene, monoterpenes and sesquiterpenes in pure air produces a large variety of organic compounds– so-called ULVOCs (Ultra-Low-Volatility Organic Compounds). As the name suggests, these are not very volatile and therefore form particles very efficiently, which can grow over time to become condensation nuclei. The enormous effect of sesquiterpenes was revealed when the researchers added sesquiterpenes into the chamber with a suspension of only isoprenes and monoterpenes. Even adding just two percent doubled the rate of new particle formation. “This can be explained by the fact that a sesquiterpene molecule consists of 15 carbon atoms, while monoterpenes consist of only ten and isoprenes only five,” says Dada.

On the one hand, the study reveals another mean by which vegetation can influence the weather and climate. Above all, however, the research results suggest that sesquiterpenes should be included as a separate factor in future climate models, alongside isopren and monoterpenes, to make their predictions more accurate. This is particularly true in light of the decrease in atmospheric sulphur dioxide concentrations and the simultaneous increase in biogenic emissions as a result of climate stress, meaning that the latter is likely to become increasingly important for our future climate. However, other studies are also needed to further improve cloud formation predictions. These are already being planned at the Laboratory for Atmospheric Chemistry. “Next,” says Imad El Haddad, Group Leader for Atmospheric Molecular Processes, “we and our CLOUD partners want to investigate what exactly happened during industrialisation, when the natural atmosphere became increasingly mixed with anthropogenic gases such as sulphur dioxide, ammonia and other anthropogenic organic compounds.”

 

Text: Jan Berndorff

 

 

 

About PSI

The Paul Scherrer Institute PSI develops, builds and operates large, complex research facilities and makes them available to the national and international research community. The institute's own key research priorities are in the fields of matter and materials, energy and environment and human health. PSI is committed to the training of future generations. Therefore about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether PSI employs 2200 people, thus being the largest research institute in Switzerland. The annual budget amounts to approximately CHF 420 million. PSI is part of the ETH Domain, with the other members being the two Swiss Federal Institutes of Technology, ETH Zurich and EPFL Lausanne, as well as Eawag (Swiss Federal Institute of Aquatic Science and Technology), Empa (Swiss Federal Laboratories for Materials Science and Technology) and WSL (Swiss Federal Institute for Forest, Snow and Landscape Research). Insight into the exciting research of the PSI with changing focal points is provided 3 times a year in the publication 5232 - The Magazine of the Paul Scherrer Institute.

Original publication:

Role of sesquiterpenes in biogenic new particle formation

Lubna Dada et al.

Science Advances, 08.09.2023

DOI: 10.1126/sciadv.adi5297

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adi5297 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Role of sesquiterpenes in biogenic new particle formation

ARTICLE PUBLICATION DATE

8-Sep-2023

 

These worms have rhythm

Peer-Reviewed Publication

COLD SPRING HARBOR LABORATORY

 

IMAGE: TO OBSERVE DEVELOPMENT IN THE C. ELEGANS WORM, SEEN HERE, PROFESSOR CHRISTOPHER HAMMELL’S TEAM AT THE CSHL CANCER CENTER EXPANDED UPON AN IMAGING TECHNIQUE ORIGINALLY DEVELOPED FOR USE IN SINGLE CELLS. THIS ALLOWED THEM TO WITNESS, FOR THE FIRST TIME, ACTIVE GENE EXPRESSION TAKING PLACE INSIDE AN ANIMAL. view more 

CREDIT: CHRISTOPHER HAMMELL/COLD SPRING HARBOR LABORATORY

There’s a rhythm to developing life. Growing from a tiny cell cluster into an adult organism takes precise timing and control. The right genes must turn on at the right time, for the right duration, and in the correct order. Losing the rhythm can lead to diseases like cancer. So, what keeps every gene on beat?

Cold Spring Harbor Laboratory (CSHL) Professor Christopher Hammell has found that in the worm C. elegans, this genetic orchestra has no single conductor. Instead, a quartet of molecules works in concert to time each developmental stage. Hammell says this process shares some similarities with the circadian clocks that control human behavior. Understanding how the worm’s clock is regulated could help explain how time affects development in other animals. Hammell explains:

“This clock we’ve discovered sets the cadence of development. It’s a coordinator of the orchestra. It controls when the trombone goes, how loud it gets, and how long the note lasts.”

Each stage of C. elegans’ development begins with two proteins, NHR-85 and NHR-23. They work together to spark a pulse of gene expression, switching on the microRNA lin-4, which controls stem cell development patterns. The pulse’s timing, strength, and duration depend on the short stretch when NHR-85 and NHR-23 interact, and another protein, LIN-42, which ends each developmental period by shutting off NHR-85.

“Mess up the orchestra—it’ll still make sound,” Hammell says. “But the way the music changes lets us know proper timing is critical for development.”

Hammell teamed with Wolfgang Keil from Paris’ Curie Institute to observe this gene expression cycle in action. C. elegans takes about 50 hours to reach adulthood. During that time, it’s always on the move, like a restless teenager. The team developed a new imaging technique to hold the tiny worm in place long enough to take pictures and video. This let them measure each developmental beat as it occurred.

“We could see every time genes turned on from birth to adulthood,” Hammell says. “This kind of imaging had never been done in animals, only in single cells.”

Hammell is now working with CSHL Professor & HHMI Investigator Leemor Joshua-Tor to image how clock proteins interact over time.

“We want to work out, with even more precision, how this clock operates,” Hammell says. “Humans can do things like write music or perform calculus, not because we have a calculus or music gene, but because our developmental clocks enable our brain to develop longer into a more complex organ.”

In other words, when it comes to development, time is truly of the essence.

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JOURNAL

Developmental Cell

DOI

10.1016/j.devcel.2023.08.006 

ARTICLE TITLE

A circadian-like gene network programs the timing and dosage of heterochronic miRNA transcription during C. elegans development

High levels of depression found among Canadian older adults with cancer during the COVID-19 pandemic

The risk of depression was higher among older adults with cancer who were lonely, those with functional limitations, and those who experienced an increase in family conflict during the pandemic

Peer-Reviewed Publication

UNIVERSITY OF TORONTO

Toronto, ON —Older adults who have had cancer had a high risk of experiencing symptoms of depression during the early months of the COVID-19 pandemic according to a new study published in Cancer Management and Research.

The study was focused on a sample of 2486 adults aged 50 and older with a history of cancer who participated in the Canadian Longitudinal Study on Aging. Among the 1765 individuals from the study who had a history of cancer but no lifetime history of depression, researchers found that 1 in 8 experienced depression for the first time during the early stages of the pandemic.

“The findings of our study indicate the substantial impact the pandemic had on the mental health of individuals with cancer,” said first author Meghan Bird, research assistant at the Factor-Inwentash Faculty of Social work at the University of Toronto. “Even among those with no history of depression, the pandemic took a significant toll on worsening their mental health.”

“Older adults with cancer also have to navigate the stress of being particularly vulnerable to severe COVID-19 related morbidity and mortality,” said co-author Andie MacNeil, researcher in the Institute for Life Course and Aging at the University of Toronto. “While strict adherence to lockdowns was an important step for many cancer patients to minimize their risk of COVID-19 infection, for many individuals this also meant forgoing social support, which is an important source of strength during cancer treatment and recovery.”

When the researchers focused on the 786 individuals who had previously experienced depression, they found that approximately one-half of these individuals experienced a recurrence or persistence of depression during the COVID-19 pandemic.

“Older adults who experienced depression in the past were a particularly vulnerable subset of the population,” said co-author Ying Jiang, Senior Epidemiologist at the Public Health Agency of Canada. She emphasized that “their difficulties were amplified if they had functional limitations, which doubled the odds of depression in this group.”

Experiencing family conflict during the pandemic was associated with an approximate four-fold risk of both new and recurrent depression among older adults with a history of cancer. This finding is in keeping with research that has identified interpersonal conflict as a risk factor for depression among older adults. Other research indicates extended periods of lockdown and quarantine increase familial conflict. “Of particular concern, the pandemic also reduced access to many coping strategies that can help mitigate family conflict, such as time spent outside the home and time spent with friends.” said co-author Grace Li, PhD candidate in the Sociology Department at the University of Victoria.

Incident depression (or depression experienced for the first time) was almost 50% higher among women. Gender roles may have contributed to this increased risk for depression. “Women are more likely to take on time-consuming caretaking roles and household labor. This aligns with existing research which suggests that caretaking roles may be associated with an increased risk of depression,” said co-author, Margaret de Groh, Scientific Manager at the Public Health Agency of Canada.

Esme Fuller-Thomson, senior author and Professor at FIFSW and Director of the Institute for Life Course & Aging says she hopes the study’s findings can help guide healthcare workers and social service providers better understand the pandemic’s impact on the mental health of people with cancer. “Future research should continue to examine depression among older adults with cancer to better understand the pandemic’s long-term impacts,” Fuller-Thomson said.

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JOURNAL

Cancer Management and Research

DOI

10.2147/CMAR.S421675 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Pandemic-induced depression among older adults with a history of cancer during the COVID-19 pandemic: Findings from the Canadian Longitudinal Study on Aging

ARTICLE PUBLICATION DATE

6-Sep-2023

 

Sleep-wake therapy gives new hope for teens with depression

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN FRANCISCO

Sleep-Wake Therapy Gives New Hope for Teens with Depression 
Promoting healthy sleep in teen night owls brings adolescents’ biology and school demands in alignment. 

School systems aren’t built for kids who fall asleep and wake up late, the so-called “night owls,” which may help explain why this group of teens is more prone to depression. 

Now, researchers at UC San Francisco have found a way to help these kids adjust to their natural sleep-cycle rhythms while still fulfilling their school responsibilities. The findings are a welcome sign for adolescents with depression, who are more likely than most to report staying up late. 

While 40% of teens overall report being night owls, in those with depression, 80% report late-night sleep patterns.

The key to success with the current intervention was teaching the night owls to structure their lives so they could sleep as late as possible, while gently training their bodies to fall asleep a little earlier. 

“A big finding here is that there is a subgroup of teens for whom treating sleep is particularly important for improving depression symptoms,” said Lauren Asarnow, PhD, a clinical psychologist with UCSF Health who specializes in sleep health. “And the other big finding is that they really need to be able to live a life that is more in line with their sleep-wake biology.

It’s Biology, Not Laziness

The study, published in August in the Journal of Child Psychology and Psychiatry, analyzed data from 42 participants with clinical depression who had been part of a larger study of 176 night-owl adolescents. Twenty-four of these adolescents received the intervention, called the Transdiagnostic Sleep and Circadian Intervention (TransS-C), and 18 received educational sessions on how to lead a healthy lifestyle. All participants kept sleep diaries and wore devices that measured the quality of their sleep. They also received 45-minute therapy sessions each week for eight weeks.

At the beginning of the study, all of the teens scored at least 40 on the Children’s Depression Rating Scale, a level that indicates clinically significant depression. A score of 28 or lower indicates remission. Six months after the treatment, the intervention group’s average score had fallen to 21.67, compared to 32.5 for the group that received the healthy lifestyle intervention. At 12 months post-treatment, the intervention scored 24.97, while controls were at 32.75.

A larger study has since been funded by the National Institute of Mental Health, and it will be open for enrollment to 200 teens in the Bay Area this fall.

About 3 million adolescents have at least one major depressive episode in a given year, and about 40% don’t respond to treatment. Teens whose natural tendencies are to fall asleep later and wake up later are at higher risk for recurrent depression, more severe depression, suicidality and poor antidepressant response, research shows. 

“There is a saying in our psychology and psychiatry clinics that the best treatment for depression and anxiety is summer break,” Asarnow said. “We need to stop calling these kids ‘lazy.’ A lot of the time it is just their biology. It’s not their fault.”
 

About UCSF Health: UCSF Health is recognized worldwide for its innovative patient care, reflecting the latest medical knowledge, advanced technologies and pioneering research. It includes the flagship UCSF Medical Center, which is a top-ranked specialty hospital, as well as UCSF Benioff Children’s Hospitals, with campuses in San Francisco and Oakland; Langley Porter Psychiatric Hospital and Clinics; UCSF Benioff Children’s Physicians; and the UCSF Faculty Practice. These hospitals serve as the academic medical center of the University of California, San Francisco, which is world-renowned for its graduate-level health sciences education and biomedical research. UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area. Visit https://www.ucsfhealth.org/. Follow UCSF Health on Facebook or on Twitter

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Follow UCSF
ucsf.edu | Facebook.com/ucsf | Twitter.com/ucsf | YouTube.com/ucsf

 

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JOURNAL

Journal of Child Psychology and Psychiatry

 

Study explores an underappreciated way warmer temperatures will impact ecosystems: Decomposition

In a new study, researchers at the Holden Arboretum improve our understanding of a mechanism for how climate change will impact natural ecosystems.

Peer-Reviewed Publication

HOLDEN FORESTS & GARDENS

 

IMAGE: RESEARCHERS AT HOLDEN FORESTS & GARDENS USED THESE SUPPLIES TO STUDY HOW DECOMPOSITION RATES CHANGE UNDER WARMING TEMPERATURES. CLOCKWISE FROM TOP LEFT, YOU’LL SEE LITTER SAMPLES, TUBES WITH SOIL SAMPLES, A SYRINGE USED TO EXTRACT GAS SAMPLES, A MASON JAR WITH A TOP FITTED WITH A RUBBER SEPTUM USED IN THE LAB STUDY, AND ADDITIONAL SOIL AND LITTER SAMPLES. view more 

CREDIT: EMMA DAWSON-GLASS/HOLDEN FORESTS & GARDENS

Our world is changing, and warming temperatures will alter our natural ecosystems. Some of these changes will be straightforward, like animal ranges creeping northward as they strive to maintain their ideal temperatures. But other changes will be more complicated, as warming sets off complex chain reactions that reverberate through these systems.

An important process in ecosystems is the decomposition of plant litter, in which dead plant material is broken down by animals, fungi, and microbes, making its nutrients accessible to the next generation of plants. How quickly this breakdown happens — the decomposition rate — is important for determining the capacity for our ecosystems to hold carbon, which ultimately influences carbon dioxide (an important greenhouse gas) levels in the atmosphere, a primary contributor to present-day warming. 

How fast this decomposition occurs is known to be affected by the composition of the plant community itself — that is, which species are present and in which relative abundances — since different kinds of plants contain different types of nutrients. Just as you might find different nutrients in rice compared to wheat, when different plant species die, the nutrients their decomposed stems and leaves contribute to the ecosystem will vary.

Decomposition rates are also affected by the microbes that live in the soil, since different bacteria and fungi carry out decomposition at different rates. Meanwhile, warming temperatures can affect both plant and microbial communities.

In a new study led by Holden Arboretum ecologists Emma Dawson-Glass and Katie Stuble, researchers uncovered how microbes, plants, and warmer temperatures all interact to alter decomposition rates in a natural ecosystem. Their work appeared August 21 in the journal Functional Ecology.

“Our study is exciting because scientists haven’t extensively explored how changes in the plant and decomposer communities will interact under climate warming,” says Emma Dawson-Glass, Research Specialist in the Stuble Community Ecology lab and lead author on the study. “Studying how decomposition is impacted by warming can help us better understand how the function of our environment is being altered by climate change. By improving our understanding of the changes caused by climate warming, we can also help to better inform climate intervention strategies.”

The new study builds on previous work that demonstrated, through experimental warming in a prairie, that higher temperatures shifted the microbial community in a way that accelerated decomposition, but shifted the plant community in a way that decelerated decomposition. With both communities at work in nature, what do these conflicting processes mean for actual decomposition in ecosystems?

To find out, the team pit these factors against each other in lab experiments to see what happens to decomposition rates when the plants, microbes, and warming temperatures all interact.

They found that soil microbial and plant communities interacted in important ways. As expected, decomposition decreased when there was more of a slower-decomposing grass (Indian grass, Sorghastrum nutans) — but only when certain microbes were in the soil. When the soil microbes had been exposed to warming, more Indian grass didn’t slow decomposition. This suggests that the microbial community actually shifted under warming in ways that make it better able to deal with more Indian grass, which itself is also more abundant under warming. 

This shift in the way microbes function could mean that changes in soil microbial and plant communities could interact to mitigate changes in decomposition under warming. These results foster improved understanding of how warming will affect ecosystems, underscoring the importance of considering multiple concurrent processes in tandem in order to understand outcomes.  

“The impacts of global warming are pervasive, but so incredibly nuanced,” says Katie Stuble, Holden Forests & Gardens scientist and senior author on the paper. “The response of one element of the environment to warming is almost certainly influenced by simultaneous shifts in other elements. Sometimes these confounding changes may exacerbate the impacts of warming, but they may also mitigate the impacts.” 

“Unpacking the intricate ways in which warming will modify various aspects of the environment, but also how these changes will interact with one another, will be a critical step in understanding how climate change is reshaping the world now, as well as into the future,” says Stuble.

Citation: Dawson-Glass, Emma; Hewins, Charlotte; Burke, David; Souza, Lara; Stuble, Katharine. 2023. Warming-induced functional shifts in the decomposer community interact with plant community compositional shifts to impact litter decomposition. Functional Ecology. DOI: 10.1111/1365-2435.14404

About Holden Forests & Gardens: Holden Forests & Gardens is made up of two of Northeast Ohio’s most important environmental and cultural institutions — the Holden Arboretum and Cleveland Botanical Garden — whose mission is to connect people with the wonder, beauty, and value of trees and plants, to inspire action for healthy communities. One of the largest public gardens in the country, Holden Forests & Gardens has 18,000 member households and an annual attendance of nearly 350,000 for whom we strive to provide inspirational and educational visitor experiences. For more information, visit holdenfg.org.

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JOURNAL

Functional Ecology

DOI

10.1111/1365-2435.14404 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Warming-induced functional shifts in the decomposer community interact with plant community compositional shifts to impact litter decomposition