Saturday, May 04, 2024

 

Birdwatching can help students improve mental health, reduce distress



NORTH CAROLINA STATE UNIVERSITY





For college students seeking to improve their mental health, a potential answer may be right outside their window: birdwatching.

A new study finds people who have nature-based experiences report better well-being and lower psychological distress than those who do not. Birdwatching in particular yielded promising results, with higher gains in subjective well-being and more reduction in distress than more generic nature exposure, such as walks. Because birdwatching is an easily accessible activity, the results are encouraging for college students – who are among those most likely to suffer from mental health problems.

“There has been a lot of research about well-being coming out through the pandemic that suggests adolescents and college-aged kids are struggling the most,” said Nils Peterson, corresponding author of the study and a professor of forestry and environmental resources at North Carolina State University. “Especially when you think about students and grad students, it seems like those are groups that are struggling in terms of access to nature and getting those benefits.

“Bird watching is among the most ubiquitous ways that human beings interact with wildlife globally, and college campuses provide a pocket where there's access to that activity even in more urban settings.”

To quantitatively measure subjective well-being, researchers used a five-question survey known as the World Health Organization-Five Well-Being Index (WHO-5). This tool asks participants to assign a rating of zero through five to statements about well-being, depending on how often they have felt that way in the last two weeks. For example, given the prompt “I have felt calm and relaxed,” a participant would mark a zero for “at no time” or a five for “all of the time.” Researchers can calculate a raw well-being score by simply adding the five responses, with zero being the worst possible and 25 the best possible quality of life.

Researchers split the participants into three groups: a control group, a group assigned five nature walks and a group assigned five 30-minute birdwatching sessions. While all three groups had improved WHO-5 scores, the birdwatching group started lower and ended higher than the other two. Using STOP-D, a similar questionnaire designed to measure psychological distress, researchers also found that nature engagement performed better than the control, with participants in both birdwatching and nature walks showing declines in distress.

This study differed from some previous research, Peterson said, in that it compared the effects of birdwatching and nature engagement to a control group rather than a group experiencing more actively negative circumstances.

“One of the studies that we reviewed in our paper compared people who listen to birds to people who listened to the sounds of traffic, and that’s not really a neutral comparison,” Peterson said. “We had a neutral control where we just left people alone and compared that to something positive.”

The study supports the idea that birdwatching helps improve mental health and opens up many avenues for future research. For example, future study could examine why birdwatching helps people feel better or the moderating effects of race, gender and other factors.

The paper, “Birdwatching linked to increased psychological well-being on college campuses: A pilot-scale experimental study,” is published in Environmental Psychology. Co-authors include Lincoln Larson, Aaron Hipp, Justin M. Beall, Catherine Lerose, Hannah Desrochers, Summer Lauder, Sophia Torres, Nathan A. Tarr, Kayla Stukes, Kathryn Stevenson and Katherine L. Martin, all from NC State.

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Note to Editors: The study abstract follows.

“Birdwatching linked to increased psychological well-being on college campuses: A pilot-scale experimental study”

Authors: Nils Peterson, Lincoln Larson, Aaron Hipp, Justin Beall, Catherine Lerose, Hannah Desrochers, Summer Lauder, Sophia Torres, Nathan Tarr, Kayla Stukes, Kathryn Stevenson, Katherine Martin

Published: April 26, 2024 in Environmental Psychology

DOI: 10.1016/j.jenvp.2024.102306

Abstract: Exposure to nature is known to improve human health, but little is known about how one of the most common forms of nature engagement, birdwatching, impacts psychological well-being - especially among campus populations at great risk for experiencing mental health challenges. This study engaged 112 campus participants in a stepped design experiment evaluating the degree to which five >30 min weekly birdwatching (n = 62) and nature walk (n = 77) exposures impacted self-reported subjective well-being (WHO-5) and psychological distress (STOP-D) levels relative to a control group (n = 81). The directions of all relationships supported hypotheses that nature-based experiences, and birdwatching in particular, would increase well-being and reduce distress. These results build on preliminary evidence of a causal relationship between birdwatching and well-being and highlight the value of considering well-being impacts for specific types of activities in nature, underscoring the need for future research with larger and more diverse samples.

 

Largest quantitative synthesis to date reveals what predicts human behavior and how to change it


Prof. Dolores Albarracín and her team dug through years of research on the science behind behavior change to determine the best ways to promote changes in behavior.



UNIVERSITY OF PENNSYLVANIA





Pandemics, global warming, and rampant gun violence are all clear lessons in the need to move large groups of people to change their behavior. When a crisis hits, researchers, policymakers, health officials, and community leaders have to know how best to encourage people to change en masse and quickly. Each crisis leads to rehashing the same strategies, even those that have not worked in the past, due to the lack of definitive science of what interventions work across the board combined with well intended but erroneous intuitions. 

To produce evidence on what determines and changes behavior, Professor Dolores Albarracín and her colleagues from the Social Action Lab at the University of Pennsylvania undertook a review of all of the available meta-analyses — a synthesis of the results from multiple studies — to determine what interventions work best when trying to change people’s behavior. What results is a new classification of predictors of behavior and a novel, empirical model for understanding the different ways to change behavior by targeting either individual or social/structural factors.

paper published today in Nature Reviews Psychology reports that the strategies that people assume will work — like giving people accurate information or trying to change their beliefs — do not. At the same time, others like providing social support and tapping into individuals’ behavioral skills and habits as well as removing practical obstacles to behavior (e.g., providing health insurance to encourage health behaviors) can have more sizable impacts.

“Interventions targeting knowledge, general attitudes, beliefs, administrative and legal sanctions, and trustworthiness — these factors researchers and policymakers put so much weight on — are actually quite ineffective,” says Albarracín. “They have negligible effects."

Unfortunately, many policies and reports are centered around goals like increasing vaccine confidence (an attitude) or curbing misinformation. Policymakers must look at evidence to determine what factors will return the investment, Albarracín says.

Co-author Javier Granados Samayoa, the Vartan Gregorian Postdoctoral Fellow at the Annenberg Public Policy Center, has noticed researchers’ tendency to target knowledge and beliefs when creating behavior change interventions.

“There's something about it that seems so straightforward — you think x and therefore you do y. But what the literature suggests is that there are a lot of intervening processes that have to line up for people to actually act on those beliefs, so it’s not that easy,” he says.

Targeting Human Behavior

To change behaviors, intervention researchers focus on the two types of determinants of human behavior: individual and social-structural. Individual determinants encompass personal attributes, beliefs, and experiences unique to each person, while social-structural determinants encompass broader societal influences on people, like laws, norms, socioeconomic status, social support, and institutional policies.

The researchers’ review explored meta-analyses of experiments in which specific social-structural determinants or specific individual determinants were tested for their ability to change behavior. For example, a study might test how learning more about vaccination might encourage vaccination (knowledge) or how reductions in health insurance copayment charges might encourage medication adherence (access).

These meta-analyses encompassed eight individual and eight social-structural determinants — part of the original classification made by the authors.

The results from the research are presented in the following three figures, which pertain to a. all behaviors analyzed, b. only health behaviors, and c. only environmental behaviors.

The figures present interventions with individual targets on the left, and interventions with social/structural targets on the right. For each determinant, the figures show whether the effects has been shown to be negligible, small, medium or large.

Individual Determinants 

The analyses researchers conducted showed that what are often assumed to be the most effective individual determinants to target with interventions were not the most effective. Knowledge (like educating people about the pros of vaccination), general attitudes (like implicit bias training), and general skills (like programs designed to encourage people to stop smoking) had negligible effects on behavior. 

What was effective at an individual level was targeting habits (helping people to stop or start a behavior), behavioral attitudes (having people associate certain behaviors as being “good” or “bad”), and behavioral skills (having people learn how to remove obstacles to their behavior).

DeterminantDefinitionExample measuresExample interventions
KnowledgeCollection of facts about an object or behavior, which can include information about the properties and consequences of a particular object or event, such as a virus or pollution; knowledge links an object or behavior to an attribute or event with absolute certaintyMeasure of literacy: "Contact with a dirty toilet is a common cause of venereal disease or sexually transmitted disease" (participant responds 'true' or 'false)

Health education

Didactic instruction about climate change in schools

General SkillsCognitive or overt routines that enable individuals to carry out various specific behavious; they involve broad capacities such as controlling attention during tasks and being able to inhibit temptations when behaviors require high levels of self-control Self-report measures of self-control, which include statements about a person's ability to make a plan or avoid temptationsBehavioral change to programs emphasizing the need to train general skills that might help individuals control undesirable behaviors 
General attitudesEvaluations of objects, persons and events; for example, prejudice is a negative judgement of a group as the attitude object, and an attitude towards cars is a positive or negative evaluation of cars as the attitude objects this type of attitude is often termed 'attitude towards the target'

Likert-scale measure of attitudes towards enviornmental protections: "Humans are severely abusing the environment"

Implicit attitude test concerning alcohol 

Mass-media health-promotion campaigns about a behavior 

Interventions aimed at weakening associations by instilling goals and threat

BeliefsSubjective assignments of probability that an object or behavior has a given attribute or outcomeSelf-report measure of conspiracy beliefs: "To what extent do you think the virus is part of a biological warfare program?"

Messages that explicitly introduce expectations about a behavior 

Growth mindset interventions in academic settings

EmotionsVisceral feelings (for example, happiness or fear) associated with a particular object, person or event; experiencing fear of climate change or disgust about a particular group of individuals are examples of emotionLikert-scale measure of emotions towards COVID-10: "I feel fearful about COVID-19"Emotional appeals that sensitize audiences to risks and include discussion of the threat posed by a problem or the audience's susceptibility to it 
Behavioral skillsRoutines that enable people to execute a target behavior, often reflected in higher levels of perceived control or efficacy concerning the behavior Self-report measure of behavioral control and confidence to perform or abstain from a behavior: "If I wanted to, it would be easy for me to exercise for at least twenty minutes, three times a week for the next fortnight"

Practicing and receiving feedback on the behavior and performing homework related to the behavior 

Asking individuals to formulate implementation intentions 

Behavioral attitudesEvaluations of a behavior as good or bad; for example, whereas an attitude towards cars is a general attitude, an attitude towards driving a car for transportation is a behavioral attitude; this type of attitude is often referred to as 'attitude towards the behavior'Semantic differential measures of attitudes linking recycling to adjectives such as good or bad: "Recycling household waste for me is something..." (participant selects from five-point response scale anchored by adjectives 'good' or 'bad')Mode of questioning designed to uncover and reduce attitudinal ambivalence towards a particular behavior
HabitsBehavioral routines that have acquired features of automaticity, meaning that they occur efficiently, without awareness, or continue even without intention and after they are no longer adaptive Measure of handwashing habit: "Washing my hands would require effort not to do"

Training to stop a behavior when faced with temptations

Introducing environmental regularity to promote habit formation

Distracting oneself from behavioral cues

 

 

 

Social-Structural Determinants

The researchers also found that what are often assumed to be the most effective social-structural persuasive strategies were not. Legal and administrative sanctions (like requiring people to get vaccinated) and interventions to increase trustworthiness — justice or fairness within an organization or government entity — (like providing channels for voters to voice their concerns) had negligible effects on behavior. 

Norms and forms to monitor and incentivize behavior had some effects, albeit small. What was most effective was focusing on targeting access (like providing flu vaccinations at work) or social support (facilitating groups of people who help one another to meet their physical activity goals).

DeterminantDefinitionSample measuresSample interventions
Legal and administrative sanctionsLegal and administrative instruments to prescribe, ban or sanction a behavior State and country records of laws coded through a policy review

Banning smoking in public establishments

Mandating vaccination

Mandating sick pay

Taxing pollution

TrustworthinessJustice or fairness within an organization or government entity, which leads constituents to follow recommendationsSelf-report measure of procedural justice: "How fair were the procedures used to handle the problem?"

Providing channels for Latinx voters to voice their concerns

Community-oriented policing that fosters non-enforcement interactions

 

Injunctive normsPerceptions of the degree to which others support a person's behaviorSelf-report measure of injunctive norms: "People who are important to me think I should use condoms"

Messages that communicate that others approve of condom use

Posting signs stating that taking the stairs is a good way to get some exercise

Monitors and remindersPhysical or digital instrument to track behavioral performance and remind users of the need to execute a behavior Self-reported use of pill boxes, diaries, and planners

Clinical reminder system for promoting preventive care

Digital watches and phone apps that promote physical activity

Descriptive normsFrequency of a behavior is a particular populationSelf-reported perception of what others do: "Most residents would vaccinate their child against COVID-19"

Comparative feedback such as a chart tracking one's energy consumption in relation too one's neighbors

Using role models to promote a target behavior

Posting signs stating that most people use the stairs

Material incentivesProviding financial or non-financial rewards in exchange for a behavior Introduction of state lottery for vaccinated residents as a rewards for vaccinationsPaying people $24 to receive the COVID-19 vaccine
Social supportInformational, instrumental or financial help to facilitate a particular behaviorSelf-reported lists of individuals who can perform instrumental, informational and emotional support functions

Leveraging family or ad-hoc groups to assist individuals to meet their physical activity goals 

Groups of Latina mothers led by 'promotoras' who support and accompany each other during health-promoting activities 

AccessMaterial or logistic resources to facilitate the performance of a behavior

Census demographics and self-report of health insurance

Self-reported health insurance

Reducing co-payments for medication

Providing health insurance

Providing basic income

 

Future Use

Granados Samayoa says that knowing which behavior change interventions work at which levels will be especially crucial in the face of growing health and environmental challenges. 

“When faced with massive problems like climate change, policy makers and other leaders have this desire to do something to change people's behavior for the better,” says Samayoa. “Our study provides valuable insights. Our research can inform future interventions and create programs that are actually effective, not just what people assume is effective. 

Albarracín is glad policymakers will have this resource now. 

“Before this study, analyses of behavior change efforts were limited to one domain, whether that was environmental science or public health. By looking at research across domains, we now have a clearer picture of how to encourage behavior change and make a difference in people’s lives,” she says.

“Our research provides a map for what might be effective even for behaviors nobody has studied. Just like masking because a critical behavior during the pandemic but we had no research on masking, a broad empirical study of intervention efficacy can guide future efforts for an array of behaviors we have not directly studied but that need to be promoted during a crisis.”

“Determinants of Behaviour and Their Efficacy As Targets of Behavioural Change Interventions” was published in Nature Reviews Psychology and authored by Dolores Albarracín, Bita Fayaz-Farkhad, and Javier Granados Samayoa. The research was funded by National Institutes of Health (NIH) grants R01MH132415, R01 AI147487, DP1 DA048570, R01 MH114847, and NSF 2031972 to Dolores Albarracín, and by the Annenberg Foundation Endowment to the Division of Communication Science at the Annenberg Public Policy Center.

About the Social Action Lab

The Social Action Lab is a group of experts and trainees in psychology, communication, and economics who seek to understand the fundamentals of social behavior and apply this knowledge to the solution of social and health problems. The lab is led by Dolores Albarracín, a Penn Integrates Knowledge Professor and Director of the Division of Communication Science in Annenberg Public Policy Center. She holds appointments in the Annenberg School for Communication, the Department of Psychology in the School of Arts & Sciences, the School of Nursing, and the Wharton School. The other two authors are Bita Fayaz-Farkhad, who is Assistant Research Professor in the Annenberg School for Communication, and Javier Granados Samayoa, the Vartan Gregorian Postdoctoral Fellow of the Annenberg Public Policy Center. 

 

Did a magnetic field collapse trigger the emergence of animals?


Evidence suggests a weak magnetic field millions of years ago may have fueled the proliferation of life.



UNIVERSITY OF ROCHESTER

Ediacaran Fauna 

IMAGE: 

UNIVERSITY OF ROCHESTER RESEARCHERS STUDIED EARTH’S MAGNETIC FIELD DURING THE TRANSFORMATIVE EDIACARAN PERIOD, WHICH SPANNED FROM ABOUT 635 TO 541 MILLION YEARS AGO. THE RESEARCH RAISES QUESTIONS ABOUT FACTORS THAT MAY HAVE FUELED THE EMERGENCE OF COMPLEX, MULTICELLULAR ORGANISMS, SUCH AS EDIACARAN FAUNA, NOTABLE FOR THEIR RESEMBLANCE TO EARLY ANIMALS.

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CREDIT: UNIVERSITY OF ROCHESTER ILLUSTRATION / MICHAEL OSADCIW




The Ediacaran Period, spanning from about 635 to 541 million years ago, was a pivotal time in Earth’s history. It marked a transformative era during which complex, multicellular organisms emerged, setting the stage for the explosion of life.

But how did this surge of life unfold and what factors on Earth may have contributed to it?

Researchers from the University of Rochester have uncovered compelling evidence that Earth’s magnetic field was in a highly unusual state when the macroscopic animals of the Ediacaran Period diversified and thrived. Their study, published in Nature Communications Earth & Environment, raises the question of whether these fluctuations in Earth’s ancient magnetic field led to shifts in oxygen levels that may have been crucial to the proliferation of life forms millions of years ago.

According to John Tarduno, the William Kenan, Jr. Professor in the Department of Earth and Environmental Sciences, one of the most remarkable life forms during the Ediacaran Period was the Ediacaran fauna. They were notable for their resemblance to early animals—some even reached more than a meter (three feet) in size and were mobile, indicating they probably needed more oxygen compared to earlier life forms.

“Previous ideas for the appearance of the spectacular Ediacaran fauna have included genetic or ecologic driving factors, but the close timing with the ultra-low geomagnetic field motivated us to revisit environmental issues, and, in particular, atmospheric and ocean oxygenation,” says Tarduno, who is also the Dean of Research in the School of Arts & Sciences and the School of Engineering and Applied Sciences. 

Earth’s magnetic mysteries

About 1,800 miles below us, liquid iron churns in Earth’s outer core, creating the planet’s protective magnetic field. Though invisible, the magnetic field is essential for life on Earth because it shields the planet from solar wind—streams of radiation from the sun. But Earth’s magnetic field wasn’t always as strong as it is today.

Researchers have proposed that an unusually low magnetic field might have contributed to the rise of animal life. However, it has been challenging to examine the link because of limited data about the strength of the magnetic field during this time.

Tarduno and his team used innovative strategies and techniques to examine the strength of the magnetic field by studying magnetism locked in ancient feldspar and pyroxene crystals from the rock anorthosite. The crystals contain magnetic particles that preserve magnetization from the time the minerals were formed. By dating the rocks, researchers can construct a timeline of the development of Earth’s magnetic field.

Leveraging cutting-edge tools, including a CO2 laser and the lab’s superconducting quantum interference device (SQUID) magnetometer, the team analyzed with precision the crystals and the magnetism locked within.

A weak magnetic field

Their data indicates that Earth’s magnetic field at times during the Ediacaran Period was the weakest field known to date—up to 30 times weaker than the magnetic field today—and that the ultra-low field strength lasted for at least 26 million years.

A weak magnetic field makes it easier for charged particles from the sun to strip away lightweight atoms such as hydrogen from the atmosphere, causing them to escape into space. If hydrogen loss is significant, more oxygen may remain in the atmosphere instead of reacting with hydrogen to form water vapor. These reactions can lead to a buildup of oxygen over time.

The research conducted by Tarduno and his team suggests that during the Ediacaran Period, the ultraweak magnetic field caused a loss of hydrogen over at least tens of millions of years. This loss may have led to increased oxygenation of the atmosphere and surface ocean, enabling more advanced life forms to emerge.

Tarduno and his research team previously discovered that the geomagnetic field recovered in strength during the subsequent Cambrian Period, when most animal groups begin to appear in the fossil record, and the protective magnetic field was reestablished, allowing life to thrive.

“If the extraordinarily weak field had remained after the Ediacaran, Earth might look very different from the water-rich planet it is today: water loss might have gradually dried Earth,” Tarduno says.

Core dynamics and evolution

The work suggests that understanding planetary interiors is crucial in contemplating the potential of life beyond Earth.

“It’s fascinating to think that processes in Earth’s core could be linked ultimately to evolution,” Tarduno says. “As we think about the possibility of life elsewhere, we also need to consider how the interiors of planets form and develop.”

This research was supported by the US National Science Foundation.

 

In medieval England, leprosy spread between red squirrels and people, genome evidence shows



CELL PRESS





Evidence from archaeological sites in the medieval English city of Winchester shows that English red squirrels once served as an important host for Mycobacterium leprae strains that caused leprosy in people, researchers report May 3 in the journal Current Biology.

“With our genetic analysis we were able to identify red squirrels as the first ancient animal host of leprosy,” says senior author Verena Schuenemann of the University of Basel in Switzerland. “The medieval red squirrel strain we recovered is more closely related to medieval human strains from the same city than to strains isolated from infected modern red squirrels. Overall, our results point to an independent circulation of M. leprae strains between humans and red squirrels during the Medieval Period.”

“Our findings highlight the importance of involving archaeological material, in particular animal remains, into studying the long-term zoonotic potential of this disease, as only a direct comparison of ancient human and animal strains allows reconstructions of potential transmission events across time,” says Sarah Inskip of the University of Leicester, UK, a co-author on the study.

Leprosy is one of the oldest recorded diseases in human history and is still prevalent to this day in Asia, Africa, and South America. While scientists have traced the evolutionary history of the mycobacterium that causes it, they didn’t know how it may have spread to people from animals in the past beyond some hints that red squirrels in England may have served as a host.

In the new study, the researchers studied 25 human and 12 squirrel samples to look for M. leprae at two archaeological sites in Winchester. The city was well known for its leprosarium (a hospital for people with leprosy) and connections to the fur trade. In the Middle Ages, squirrel fur was widely used to trim and line garments. Many people also kept squirrels trapped wild squirrels as kits in the wild and raised them as pets.

The researchers sequenced and reconstructed four genomes representing medieval strains of M. leprae, including one from a red squirrel. An analysis to understand their relationships found that all of them belonged to a single branch on the M. leprae family tree. They also showed a close relationship between the squirrel strain and a newly constructed one isolated from the remains of a medieval person. They report that the medieval squirrel strain is more closely related to human strains from medieval Winchester than to modern squirrel strains from England, indicating that the infection was circulating between people and animals in the Middle Ages in a way that hadn’t been detected before.

“The history of leprosy is far more complex than previously thought,” Schuenemann said. “There has been no consideration of the role that animals might have played in the transmission and spread of the disease in the past, and as such, our understanding of leprosy’s history is incomplete until these hosts are considered. This finding is relevant to today as animal hosts are still not considered, even though they may be significant in terms of understanding the disease’s contemporary persistence despite attempts at eradication.” 

“In the wake of COVID-19, animal hosts are now becoming a focus of attention for understanding disease appearance and persistence,” Inskip said. “Our research shows that there is a long history of zoonotic diseases, and they have had and continue to have a big impact on us.”

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This work was supported by the Swiss State Secretariat for Education, Research and Innovation SERI funded ERC Consolidator Project “RESERVOIR,” the University of Zurich’s University Research Priority Program “Evolution in Action: From Genomes to Ecosystems,” and the Fondation Raoul Follereau and the Heiser Program of the New York Community Trust for Research in Leprosy.

Current Biology, Urban, Blom, and Avanzi et al.: “Ancient Mycobacterium leprae genome reveals medieval English red squirrels as animal leprosy host.” https://www.cell.com/current-biology/fulltext/S0960-9822(24)00446-9 

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

 

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Lepra in the middle ages: New insights on transmission pathways through squirrels



Peer-Reviewed Publication

UNIVERSITY OF BASEL

Lady holding a pet squirrel 

IMAGE: 

A LADY PLAYS WITH A PET SQUIRREL, WEARING A BELLED COLLAR, IN THE EARLY 14TH CENTURY LUTTRELL PSALTER.

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CREDIT: BRITISH LIBRARY BOARD MS ADD. MS 42130 F. 33R




Researchers at the University of Basel and the University of Zurich have been able to prove that British squirrels carried leprosy bacteria as early as the Middle Ages. Further results revealed a link between the pathogens found in the medieval rodents and those in the local human population during that period.

Skin spots, deformed noses, ulcers: leprosy, is an infectious disease that can bring about some serious symptoms. The bacterium responsible, Mycobacterium leprae, which still infects around 200,000 people each year especially in the Global South, also has a long history in Europe. The international research group led by paleogeneticist Professor Verena Schünemann (University of Basel, formerly University of Zurich) used archaeological findings to identify red squirrels (Sciurus vulgaris) as hosts for M. leprae in medieval England. The researchers also discovered that the leprosy bacteria in medieval squirrels were closely related to those isolated from medieval human skeletons from the same region. The results were published in the journal “Current Biology”.

From squirrels to humans or vice versa?

“This similarity shows us that leprosy bacteria were probably transmitted between animals and humans at that time,” says Schünemann. However, she stresses that, based on current knowledge, it is not clear how this took place. “We don’t know whether the squirrels infected humans or whether humans were the ones to introduce the disease to the animals,” says Schünemann.

There were certainly a number of points of contact between humans and squirrels during the Middle Ages. One key aspect was fur trade, which provided the highly sought-after squirrel fur for the upper echelons of society. Especially in the 11th and 12th centuries, for example, entire coats made of squirrel fur were produced for the various royal families. Furthermore, squirrels were also kept as pets, in royal courts as well as nunneries.

Genetic analysis from 20 milligrams

For their study, the researchers focused on the city of Winchester in southern England. The material necessary for the genetic analysis originates from two different archaeological sites within the city. The human remains were extracted from the location of a former leprosarium, a care facility specifically for people suffering from leprosy. The researchers were able to examine the medieval squirrels thanks to hand and foot bones found at a former skinner’s shop. “We carried out the genetic analyses on the squirrels’ tiny hand and foot bones, which weigh between 20 and 30 milligrams. That is not a lot of material,” explains Christian Urban, first author of the study.

For the researchers, the results are particularly important for predicting leprosy in the future. Because to this day, it is not completely clear how the disease spreads. “Our One Health approach prioritizes finding out more about the role animals played in the spread of diseases in the past”, says Schünemann. “A direct comparison between ancient animal and human strains enables us to reconstruct potential transmission events over time and helps to form conclusions about the long-term zoonotic potential of the disease”, she adds.

The results are therefore relevant for today, as animals still receive very little attention as hosts of leprosy, even though they may be important for understanding the current persistence of the disease despite all attempts to eradicate it.

 

Ice shelves fracture under weight of meltwater lakes




UNIVERSITY OF COLORADO AT BOULDER





When air temperatures in Antarctica rise and glacier ice melts, water can pool on the surface of floating ice shelves, weighing them down and causing the ice to bend. Now, for the first time in the field, CIRES-led research shows that ice shelves don’t just buckle under the weight of meltwater lakes — they fracture. As the climate warms and melt rates in Antarctica increase, this fracturing could cause vulnerable ice shelves to collapse, allowing inland glacier ice to spill into the ocean and contribute to sea level rise.

“Ice shelves are extremely important for the Antarctic Ice Sheet’s overall health as they act to buttress or hold back the glacier ice on land,” said Alison Banwell, a CIRES scientist in the Earth Science and Observation Center (ESOC) and lead author of the study published today in the Journal of Glaciology. “Scientists have predicted and modeled that surface meltwater loading could cause ice shelves to fracture, but no one had observed the process in the field, until now.”

The new work may help explain how the Larsen B Ice Shelf abruptly collapsed in 2002. In the months before its catastrophic breakup, thousands of meltwater lakes littered the ice shelf’s surface, which then drained over just a few weeks.

To investigate the impacts of surface meltwater on ice shelf stability, Banwell and her colleagues from the University of Cambridge, University of Oxford, and University of Chicago traveled to the George VI Ice Shelf on the Antarctic Peninsula in November 2019. First, the team identified a depression or “doline” in the ice surface that had formed by a previous lake drainage event where they thought meltwater was likely to pool again on the ice. Then, they ventured out into the frigid landscape on snowmobiles, pulling all their science equipment and safety gear behind on sleds. 

Around the doline, the team installed high-precision GPS stations to measure small changes in elevation at the ice’s surface, water-pressure sensors to measure lake depth, and a timelapse camera system to capture images of the ice surface and meltwater lakes every 30 minutes. 

In 2020, the COVID-19 pandemic brought their fieldwork to a screeching halt. When the team finally made it back to their field site in November 2021, only two GPS sensors and one timelapse camera remained; two other GPS and all water pressure sensors had been flooded and buried in solid ice. Fortunately, the surviving instruments captured the vertical and horizontal movement of the ice’s surface and images of the meltwater lake that formed and drained during the record-high 2019/2020 melt season.

GPS data indicate that the ice in the center of the lake basin flexed downward about a foot in response to the increased weight from meltwater. That finding builds upon previous work led by Banwell that produced the first direct field measurements of ice shelf buckling caused by meltwater ponding and drainage. 

The team also found that the horizontal distance between the edge and center of the meltwater lake basin increased by over a foot. This was most likely due to the formation and/or widening of circular fractures around the meltwater lake, which the timelapse imagery captured. Their results provide the first field-based evidence of ice shelf fracturing in response to a surface meltwater lake weighing down the ice. 

“This is an exciting discovery,” Banwell said. “We believe these types of circular fractures were key in the chain reaction style lake drainage process that helped to break up the Larsen B Ice Shelf.” 

The work supports modeling results that show the immense weight of thousands of meltwater lakes and subsequent draining caused the Larsen B Ice Shelf to bend and break, contributing to its collapse. 

“These observations are important because they can be used to improve models to better predict which Antarctic ice shelves are more vulnerable and most susceptible to collapse in the future,” Banwell said.

 

Sister cities can help communities better navigate the climate crisis, suggests Rice research




RICE UNIVERSITY





Anthropologists at Rice University suggest in a new study that establishing networks of 'sister cities' dedicated to addressing the impact of natural disasters can mitigate the devastation wrought by climate change.

Published in the journal Nature, “Sister cities for the Anthropocene” by professors Cymene Howe and Dominic Boyer explores the connectivity of “sister cities,” broad-based, long-term, legal or social partnerships between two similar-sized communities in two countries. The original Sister Cities International program was born out of the aftermath of World War II and fears of nuclear conflict in the 1950s.

Historically, these relationships have centered on social and political factors like trade relationships, diplomacy and more. But Howe and Boyer believe they can be powerful tools to aid in dealing with the physical effects of climate change, especially as cities deal with things like wildfires, extreme storms and more. As a result, they recommend forming a network called “Sister Cities for the Anthropocene” to help track and raise awareness of the spread of related impacts and responses to climate-related disasters in urban communities across the world.

“The idea of this network is to create relationships and networks that help formulate ideas and best practices to cope with the consequences of climate change that are already with us, including the effects of natural disasters,” Howe said. 

“This network also takes into account the consequences that we know are coming in the future,” Boyer said. “We know that we will have more extreme storms, more drought andmore wildfires. We want to prevent as many of those terrible effects as we can.”

Howe and Boyer wrote that in regions affected by chronic wildfire and droughts, “sister cities” might learn how other urban communities are assessing predictions of a hotter, drier future and making plans to adapt. In areas where flooding, sea-level rise or extreme storms increasingly threaten residents, “sister cities” can look at what responses have been initiated by nongovernmental organizations, community groups and media organizations and how the outcomes and impacts of these initiatives compare.

Howe said that while it is encouraging that many city leaders, urban professionals and residents are already talking about climate change, related disasters and mitigation strategies, this network would formalize relationships between cities and bring more public attention to the effects of climate change. 

Howe and Boyer’s research is supported by the National Science Foundation’s Arctic Social Sciences Program in the Office of Polar Programs (award No. 2030474).