It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, July 15, 2021
GUNS IN AMERICA
Self-inflicted firearm injuries three times more common in rural youth
Targeted interventions needed in rural areas to prevent self-harm among youth
ANN & ROBERT H. LURIE CHILDREN'S HOSPITAL OF CHICAGO
A national study published in the Journal of Pediatrics found that Emergency Department (ED) visits by youth for self-harm were nearly 40 percent higher in rural areas compared to urban settings. Strikingly, ED visits by youth for self-inflicted firearm injuries were three times more common in rural areas. Youth from rural areas presenting to the ED for suicidal ideation or self-harm also were more likely to need to be transferred to another hospital for care, which underscores the insufficient mental health resources in rural hospitals.
"Our study used pre-pandemic data, and we know that increased attention to youth mental health is even more pressing now everywhere, but especially in rural settings to prevent self-harm in youth," said lead author Jennifer Hoffmann, MD, pediatric emergency medicine physician at Ann & Robert H. Lurie Children's Hospital of Chicago and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine. "We need universal screening for suicidal ideation for all children and adolescents age 10 and up who present in the ED to identify youth at risk and intervene before tragedy occurs."
The study used national data on suicidal ideation or self-harm in youth (ages 5-19 years) from a sample of EDs across the country, including those in general hospitals and children's hospitals. Dr. Hoffmann and colleagues extrapolated the results to reach national estimates.
Dr. Hoffmann explains that a number of factors contribute to higher suicide rates and self-harm in rural youth. Access to mental healthcare is a huge challenge, she says. Shortages of pediatric mental health professionals in rural areas play a significant role, requiring patients to travel long distances for help, which is a barrier for many. Also, lower family income and higher unemployment rates in rural areas may result in poor insurance coverage, especially for mental health. In small towns, there are also concerns with anonymity, which may cause delays in seeking care until a crisis brings the child to the ED. Rural families are also more likely to own firearms, so increased access to firearms may account for the high degree of disparity in self-inflicted firearm injuries.
"We need to improve mental health training for ED providers, allocate more resources and implement policies in rural hospitals on managing young patients who present with suicidal ideation or self-harm," said Dr. Hoffmann. "More widespread use of tele-psychiatry also might help prevent unnecessary transfers to other hospitals. But even more importantly, we need to train primary care providers to help diagnose and treat mental health issues earlier, so we can prevent self-inflicted injuries and death."
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Research at Ann & Robert H. Lurie Children's Hospital of Chicago is conducted through the Stanley Manne Children's Research Institute. The Manne Research Institute is focused on improving child health, transforming pediatric medicine and ensuring healthier futures through the relentless pursuit of knowledge. Lurie Children's is ranked as one of the nation's top children's hospitals by U.S. News & World Report. It is the pediatric training ground for Northwestern University Feinberg School of Medicine. Last year, the hospital served more than 220,000 children from 48 states and 49 countries.
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Food insufficiency linked to lack of mental health services during pandemic
Americans experiencing food insufficiency more likely to use antidepressant medications
A new national study published in Public Health Nutrition on July 15 found that Americans experiencing food insufficiency were three times as likely to lack mental health support during the COVID-19 pandemic than those not experiencing food insufficiency.
The most extreme form of food insecurity, food insufficiency occurs when families do not have enough eat. Among a nationally representative sample of 68,611 adults who participated in the US Census Household Pulse Survey in October 2020, 11% reported food insufficiency. Of those, 24% also reported an unmet mental health need compared to 9% of food-sufficient adults.
"Hunger, exhaustion, and stress related to not getting enough food to eat may lead to depression and anxiety," says lead author, Jason Nagata, MD, assistant professor of pediatrics at the University of California, San Francisco.
"The experience of food insecurity could lead affected people to prioritize food over other needs such as seeking health care, using up considerable time and energy to navigate food pantries and free meal services, or locate and visit affordable food stores."
Food insufficiency was also associated with higher use of psychiatric medications: 27% of food-insufficient adults reported psychiatric medication use compared to 19% of food-sufficient adults.
"To better address these problems, medical professionals, social workers, and clinicians can screen patients for both symptoms of anxiety and depression to ensure they have sufficient access to food," says co-author Kyle T. Ganson, PhD, assistant professor at the University of Toronto's Factor-Inwentash Faculty of Social Work.
The researchers argue that clinicians should assess for food insecurity and provide referrals to food assistance programs.
"Policymakers should focus on increasing funding for food assistance and mental health services as part of pandemic relief legislation," says Nagata. "Expanding access to supplemental food programs may help to mitigate the need for more mental health services during the pandemic."
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How spiders distinguish living from non-living using motion-based visual cues
Ability to identify other animals from relative positioning of the joints not unique to vertebrates
IMAGE: UNKNOWN JUMPING SPIDER, AUGUST 2012, BELTSVILLE, MARYLAND, BENJAMIN A COULTER HELPED NARROW THIS DOWN TO PERHAPS AN IMMATURE THIODINA SYLVANA view more
CREDIT: SAM DROEGE, USGS BEE INVENTORY AND MONITORING LAB, FLICKR
Jumping spiders can distinguish living from non-living objects in their peripheral vision using the same cues used by humans and other vertebrate animals, according to a study publishing 15th July 2021 in the open-access journal PLOS Biology by Massimo De Agrò of Harvard University in the United States.
The ability to detect other living creatures in your surroundings is a key skill for any animal - it is crucial for finding mates, avoiding predators, and catching prey. The movements of vertebrates and invertebrates are distinct from inanimate objects because their rigid, jointed bones and exoskeletons constrain the relative positioning of certain body parts. Most vertebrates can recognize this biological pattern of movement from very limited visual information, such as a point-light display, which shows dots representing the positions of the main joints.
To investigate this phenomenon in invertebrates for the first time, researchers partially restrained 60 wild-caught jumping spiders (Menemerus semilimbatus) on a spherical treadmill and used a computer screen to show point-light displays on each side of their peripheral vision (only visible to their lateral eyes). They found that spiders were more likely to try to turn and face displays that showed random movements, compared to those that moved in a more biological way, with the distances between joints constrained.
The result seems contrary to the expectation that spiders should focus their attention on objects in their surroundings that appear to be living - potential prey, mate or predator. However, the authors suggest that this behavior may allow the spiders to focus their forward-facing primary eyes on unidentifiable objects to get a better look. Complex vision evolved independently in vertebrates and arthropods and so the ability to distinguish living from non-living motion using the relative positioning of the joints has most likely arisen convergently in the two groups of animals.
"Jumping spiders' secondary eyes confirm themselves to be a marvelous tool," the researchers add. "In this experiment, we observed how they alone can tell apart living from non-living organisms, using the semi-rigid pattern of motion that characterize the formers and without the aid of any shape cue. Finding the presence of this skill, previously known only in vertebrates, opens up new and exciting perspectives on the evolution of visual perception. My co-authors and I can't wait to see what other visual cues can be perceived and understood by these tiny creatures."
Citation: De Agrò M, Rößler DC, Kim K, Shamble PS (2021) Perception of biological motion by jumping spiders. PLoS Biol 19(7): e3001172. https://doi.org/10.1371/journal.pbio.3001172
Funding: PSS was supported by the John Harvard Distinguished Science Fellows Program within the FAS Division of Science, Harvard University. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist
A new spidey sense
Harvard study shows jumping spiders can distinguish living objects from non-living objects based on their movement
Add this to the list of real-life spidey senses: Harvard researchers have shown that jumping spiders are able to tell the difference between animate objects and inanimate objects -- an ability previously known only in vertebrates, including humans.
Using a specialized treadmill system and a point-light display animation, the team of scientists found that these spiders are able to recognize biological motion. This type of motion refers to the visual movements that come from living organisms when they are moving. The visual cue is how people, even babies, can tell someone is another person just by the way their bodies move. Many animals can do this, too.
The ability, which is critical for survival, is evolutionarily ancient since it is so widespread across vertebrates. The study from the Harvard team is believed to be the first demonstration of biological motion recognition in an invertebrate. The findings pose crucial questions about the evolutionary history of the ability and complex visual processing in non-vertebrates.
"[It] opens the possibility that such mechanisms might be widespread across the animal kingdom and not necessarily related to sociality," the researchers wrote in the paper, which published in PLOS Biology on Thursday.
The study was authored by a team of researchers who were John Harvard Distinguished Science Fellows during the time of the study or are current fellows. Massimo De Agrò, now a researcher at an animal comparative economics lab in Regensburg, Germany, led the work. Paul Shamble, a current fellow, and Daniela C. Rößler, and Kris Kim, former fellows, co-authored the study.
The researchers chose jumping spiders to test biological motion cues because the animals are among the most visually adept of all arthropods. With eight eyes, for example, vision plays a central role in a wide range of behaviors.
They placed the jumping spiders, a species called Menemerus semilimbatus, into a forced choice experiment. They suspended the spiders above a spherical treadmill so their legs could make contact with it. The spiders were kept in a fixed position so only its legs could move, transferring its intended direction to the sphere which spun freely because of a constant stream of compressed air shooting up below it.
(Friendly disclaimer: No spiders were harmed during the experiment and all were freed in the same place they were captured afterwards.)
Once in position, the spiders were presented two animations as stimuli. The animations were called point-light displays, each consisting of a dozen or so small lights (or points) that were attached to key joints of another spider so they could record its movements. The body itself is not visible, but the digital points give a body-plan outline and impression of a living organism. In humans, for example, it only takes about eleven dots on the main joints of the body for observers to correctly identify it as another person.
For the spiders, the displays followed the motion of another spider walking. Most of the displays gave the impression of seeing a living animal. Some of the displays were less real than others and one, called a random display, did not give the impression it was living.
The researchers then observed how the spiders reacted and which light display they turned toward on the treadmill. They found the spiders reacted to the different point-light displays by pivoting and facing them directly, which indicated that the spiders were able to recognize biological motion.
Curiously, the team found the spiders preferred rotating towards the more artificial displays and always toward the random one when it was part of the choice. They initially thought they would turn more toward the displays simulating another spider and possible danger, but the behavior made sense in the context of jumping spiders and how their secondary set of eyes work to decode information.
"The secondary eyes are looking at this point-light display of biological motion and it can already understand it, whereas the other random motion is weird and they don't understand what's there," De Agrò said.
The researchers hope to look into biological motion recognition in other invertebrates such as other insects or mollusks. The findings could lead to greater understanding of how these creatures perceive the world, De Agrò said.
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Arrival of land plants changed Earth's climate control system
The arrival of plants on land about 400 million years ago may have changed the way the Earth naturally regulates its own climate, according to a new study led by researchers at UCL (University College London) and Yale.
IMAGE: WATER COLLECTS ON MOSSES. THE FIRST LAND PLANTS WERE THOUGHT TO BE NON-VASCULAR, LIKE MOSSES. view more
CREDIT: KATMAI PRESERVE NPS PHOTO/RUSS TAYLOR
The arrival of plants on land about 400 million years ago may have changed the way the Earth naturally regulates its own climate, according to a new study led by researchers at UCL and Yale.
The carbon cycle, the process through which carbon moves between rocks, oceans, living organisms and the atmosphere, acts as Earth's natural thermostat, regulating its temperature over long time periods.
In a new study, published in the journal Nature, researchers looked at samples from rocks spanning the last three billion years and found evidence of a dramatic change in how this cycle functioned about 400 million years ago, when plants started to colonise land.
Specifically, the researchers noted a change in the chemistry of seawater recorded in the rock that indicates a major shift in the global formation of clay - the "clay mineral factory" - from the oceans to the land.
Since clay forming in the ocean (reverse weathering) leads to carbon dioxide being released into the atmosphere, while clay on land is a byproduct of chemical weathering that removes carbon dioxide from the air, this reduced the amount of carbon in the atmosphere, leading to a cooler planet and a seesawing climate, with alternating ice ages and warmer periods.
The researchers suggested the switch was caused by the spread of land plants keeping soils and clays on land, stopping carbon from being washed into the ocean, and by the growth in marine life using silicon for their skeletons and cell walls, such as sponges, single-celled algae and radiolarians (a group of protozoa), leading to a drop in silicon in the seawater required for clay formation.
Senior author Dr Philip Pogge von Strandmann (UCL Earth Sciences) said: "Our study suggests that the carbon cycle operated in a fundamentally different way for most of Earth's history compared to the present day.
"The shift, which occurred gradually between 400 to 500 million years ago, appears to be linked to two major biological innovations at the time: the spread of plants on land and the growth of marine organisms that extract silicon from water to create their skeletons and cells walls.
"Before this change, atmospheric carbon dioxide remained high, leading to a stable, greenhouse climate. Since then, our climate has bounced back and forth between ice ages and warmer periods. This kind of change promotes evolution and during this period the evolution of complex life accelerated, with land-based animals forming for the first time.
"A less carbon-rich atmosphere is also more sensitive to change, allowing humans to influence the climate more easily through the burning of fossil fuels."
First author Boriana Kalderon-Asael, a PhD student at Yale University, said: "By measuring lithium isotopes in rocks spanning most of Earth's history, we aimed to investigate if anything had changed in the functioning of the carbon cycle over a large time scale. We found that it had, and this change appears to be linked to the growth of plant life on land and silicon-using animal life in the sea."
In the study, researchers measured lithium isotopes in 600 samples of rock taken from many different locations around the world. Lithium has two naturally occurring stable isotopes - one with three protons and three neutrons, and one with three protons and four neutrons.
When clay forms slowly on land, it strongly favours lithium-6, leaving surrounding water enriched with the other, heavier isotope, lithium-7. Analysing their samples using mass spectrometry, the researchers found a rise in the levels of lithium isotope-7 in seawater recorded in the rock occurring between 400 and 500 million years ago, suggesting a major shift in Earth's clay production coinciding with the spread of plants on land and emergence of silicon-using marine life.
Clay forms on land as a residue of chemical weathering, the primary long-term process through which carbon dioxide is removed from the atmosphere. This occurs when atmospheric carbon combines with water to form a weak acid, carbonic acid, which falls to the ground as rain and dissolves rocks, releasing ions including calcium ions that flow into the ocean. Eventually, the carbon is locked up in rocks on the ocean floor. In contrast, carbon drawdown by plant photosynthesis is negated once the plants decay, and rarely affects carbon dioxide levels on timescales longer than a few hundred years.
When clay forms in the ocean, carbon stays in the water and is eventually released into the air as part of the continual exchange of carbon that occurs when air meets water.
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The study received support from the European Research Council and NASA.
High-ranking hyena mothers pass their social networks to their cubs
Using 27 years of detailed data on hyena social interactions, a team led by Penn biologists nailed down a pattern of social network inheritance and its implications for social structure, rank, and survival
IMAGE: USING 27 YEARS OF DETAILED DATA ON HYENA SOCIAL INTERACTIONS, A TEAM LED BY PENN BIOLOGISTS NAILED DOWN A PATTERN OF SOCIAL NETWORK INHERITANCE AND ITS IMPLICATIONS FOR SOCIAL STRUCTURE,... view more
CREDIT: KATE SHAW YOSHIDA
Hyenas are a highly social species, living in groups that can number more than 100. But within their clans, there is order: A specific matrilineal hierarchy governs societies in this species where females are dominant to males.
While researchers have intensively studied the social structure of hyenas and other animals, it's only recently that scientists have begun to investigate how this structure arises. A new study led by Penn biologists, which relies upon 27 years of detailed observations of hyena social behavior collected by researchers at Michigan State University, pulls back the curtain on how social order comes to be.
Their findings show that hyenas inherit their mother's social networks, so their social connections resemble their mother's. However, offspring of higher-ranking individuals more faithfully replicate their mother's interactions, winding up with social networks that more closely resemble their mother's than do offspring of females that rank lower on the clan's social ladder. The team reported their findings in the journal Science.
"We knew that the social structure of hyenas is based in part on one's rank in the agonistic hierarchy, which we know is inherited from mothers" says Erol Akçay, a study coauthor and associate professor in Penn's School of Arts & Sciences. "But what we found, that affiliative, or friendly interactions, are also inherited, hadn't been shown."
"This is a very simple process of social inheritance that we show works very, very well," says Amiyaal Ilany, a senior lecturer at Israel's Bar-Ilan University. "Individuals that were born to higher rank are more accurate in their inheritance, and they have good reason to do so. It fits well with what is already known about inheritance of rank. There are very strict rules about what place you sit in the hierarchy if you are a hyena."
The work builds on a theoretical model of social network inheritance Akçay and Ilany developed in 2016. According to that simple framework, animals establish their networks by "social inheritance," or copying their mother's behaviors. The model fit well with snapshots of real-world social networks from not only hyenas but also three other social species: bottle-nosed dolphins, rock hyrax, and sleepy lizards.
In the new work, the team aimed to refine their model to better understand the intricacies of social inheritance in hyenas. They were fortunate to have a robust dataset collected by Akçay and Ilany's coauthor, zoologist Kay Holekamp of Michigan State University, consisting of 27 years of detailed accounting of a clan's social interactions.
"We realized we could use that dataset to directly test our model, to see if social ties are inherited or not," Akçay says.
Field biologists from Holekamp's research group had meticulously tracked how hyenas in a clan interacted, including who spent time with whom as well as the social rank of each member. To do so, researchers spent months getting to know each member of the clan by sight.
"They are there year-round, every day, identifying individuals by their specific spot patterns and other characteristics," Ilany says.
These observations allowed Akçay, Ilany, and Holekamp to map out hyenas' social networks based on which individuals spent time close together.
"This use of proximity to track social networks isn't possible with humans, as two strangers might randomly get into an elevator together," Ilany says. "But with hyenas, if one individual gets within a few meters of another, that suggests that they have a social connection."
With this picture of each individual's social affiliations in hand, the researchers compared the social networks of mothers to their offspring. "We developed a new metric to measure social inheritance, to track how faithfully an offspring's network reproduces its mother's network," Akçay says.
Hyena cubs stick close to their mothers for the first couple years of life, so the networks of mothers and their offsprings were quite similar to start. However, the researchers noticed that even as the young stopped spending so much time in close proximity to their mothers they still sustained quite similar networks, particularly for female offspring, who generally remain members of the clan for life. "We have data in some cases showing that the network similarity between mothers and offspring, especially female offspring, was still very high after six or so years," says Ilany. "You may not be seeing your mother as often, or she even may have died, but you still have similar friends."
This pattern was especially strong for the higher-ranking mothers, for whom social inheritance was the strongest in the group.
"That is kind of intuitive because things like that happen in human society as well," Akçay says. "It happens so much we take it for granted. We inherit social connections, and there's a lot of social science research that shows that this has a huge influence on people's life trajectory."
Offspring of lower-ranking mothers were less likely to reproduce their mother's social networks, perhaps trying to compensate for their more lowly origins by associating with a greater variety of individuals.
There is no genetic inheritance of rank or close associates in this species, so in Holekamp's opinion one of the most remarkable things about the phenomenon documented here is that the youngsters' relationships with their mothers' close associates are all learned very early in life. One explanation for why inheritance of social networks works better for high- than for low-ranking hyenas may be that low-ranking females tend to go off on their own more often to avoid competition with higher-ranking hyenas, so their cubs have fewer learning opportunities than cubs of high-ranking females.
Mother-offspring pairs with more similar social networks also lived longer, the team found. This effect on survivorship may owe to the fact that offspring who spend more time with their mothers and thus replicate their social networks benefit from the increased care.
Social rank also had an effect on survivorship and reproductive success.
"Rank is super important," says Akçay. "If you're born to a lower-ranked mother, you are less likely to survive and to reproduce."
The researchers note that social network inheritance likely contributes to a group's stability and also has implications for how behaviors are learned and spread through groups.
The study also underscores how factors other than genetics hold sway in key evolutionary outcomes, including reproductive success and overall survival. "A lot of things that are considered by default to be genetically determined may depend on environmental and social processes," says Ilany.
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Erol Akçay is an associate professor of biology in the School of Arts & Sciences at the University of Pennsylvania.
Amiyaal Ilany is a senior lecturer at the Mina and Everard Goodman Faculty of Life Sciences at Bar-Ilan University and completed a postdoctoral fellowship working with Akçay at Penn.
Kay Holekamp is a professor of zoology at Michigan State University.
The research was supported by the Israel Science Foundation (grants 244/19 and 245/19), U.S. Army Research Office (Grant W911NF-17-1-0017), Israel-U.S. Binational Science Foundation (grants 2015088 and 2019156), and National Science Foundation (grants 185
Inherited social networks shape spotted hyena society and survival
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE
In spotted hyena societies, inherited social networks - passed from mothers to offspring - are essential to hyena life and survival, according to a new study. While the structure of animal social networks plays an important role in all social processes as well as health, survival and reproductive success, the general mechanisms that determine social structure in the wild remain unknown. One proposed model, termed social inheritance, suggests that an offspring's social affiliations tend to resemble those of their parents, particularly those of the mother. Previous research has indicated that these inherited social networks may influence social structure across generations in multiple species. Here, Amiyaal Ilany and colleagues evaluate the role of social inheritance in spotted hyena society, which is female-dominated and highly structured. Combining social network analysis and a transgenerational dataset comprised of 73,767 social observations among a population of wild hyenas collected over 27 years, Ilany et al. found that that the social relationships of juvenile hyenas are similar to those of their mothers and that the degree of similarity increases with the mother's social rank. What's more, the results show that the strength of the maternal relationship affects social inheritance and is also positively correlated with the long-term survival for both mother and offspring. According to the authors, the findings suggest that selection for social inheritance might play an essential role in shaping hyena social behavior and the fitness of individual hyenas. "Future work should seek to examine how widely specific social relationships are inherited in a range of population structures and what implications this has for the rate of evolution of the many processes that depend on social network structure," write Josh Firth and Ben Sheldon in a related Perspective.
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Disclaimer:AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.3934 and 1755089).
CAPTION
A massive study of data collected over 27 years, published today in the journal Science, sheds new light on social networks, rank and survival of spotted hyenas.
Dr. Amiyaal Ilany, a biologist at Bar-Ilan University in Israel, integrates behavioral ecology, network science, and social science, to study broad aspects of social behavior in the wild. As a postdoctoral researcher at the University of Pennsylvania, he developed, together with Dr. Erol Akçay, a theoretical model suggesting that social inheritance - in which offspring inherit their social bonds from their parents, either passively or by copying them - could explain the social networks of multiple species. To test their model Ilany and Akçay forged a partnership with Dr. Kay Holekamp, of Michigan State University. Holekamp had spent the previous 27 years observing wild spotted hyenas in Kenya. Poring over Holekamp's data, which included nearly 74,000 social interactions among the spotted creatures, they were able to show, for the first time on such a large scale, that their model correctly hypothesized that a process of social inheritance determines how offspring relationships are formed and maintained. Their study also elucidates the major role that social rank plays in structuring the spotted hyena clan, and how this affects survival.
CREDIT
Lily Johnson-Ulrich
Among spotted hyenas, social ties are inherited
Massive study of data collected over 27 years sheds light on social networks, rank, and survival of this African species
IMAGE: A MASSIVE STUDY OF DATA COLLECTED OVER 27 YEARS, PUBLISHED TODAY IN THE JOURNAL SCIENCE, SHEDS NEW LIGHT ON SOCIAL NETWORKS, RANK AND SURVIVAL OF SPOTTED HYENAS. DR. AMIYAAL ILANY, A... view more
CREDIT: KATE SHAW YOSHIDA
Social networks among animals are critical to various aspects of their lives, including reproductive success and survival, and could even teach us more about human relationships.
Dr. Amiyaal Ilany, a biologist at the Mina and Everard Goodman Faculty of Life Sciences at Bar-Ilan University in Israel, integrates behavioral ecology, network science, and social science, to study broad aspects of social behavior in the wild. As a postdoctoral researcher at the University of Pennsylvania, he developed, together with Dr. Erol Akçay, a theoretical model suggesting that social inheritance - in which offspring inherit their social bonds from their parents, either passively or by copying them - could explain the social networks of multiple species.
In a study published today in the journal Science, the researchers show, for the first time on such a large scale, that their model correctly hypothesized that a process of social inheritance determines how offspring relationships are formed and maintained. Their study also elucidates the major role that social rank plays in structuring the spotted hyena clan, and how this affects survival.
To test their model Ilany and Akçay forged a partnership with Dr. Kay Holekamp, of Michigan State University. Holekamp had spent the previous 27 years observing wild spotted hyenas in Kenya. The researchers pored over Holekamp's data, which included nearly 74,000 social interactions among the spotted creatures.
"Social affiliations are, indeed, inherited within clusters of hyenas. The plethora of data on spotted hyenas that was collected by Kay Holecamp provided us with a golden opportunity to test the model we developed several years ago," says Dr. Ilany, the lead author of the study. "We found overwhelming evidence that social connections of offspring are similar to those of the mother. A mother who has social affiliations with another hyena can connect her offspring to that hyena and the two, in turn, will form a social bond. Even after the mother-offspring bond itself weakens dramatically, the offspring still remain connected to their mother's friends."
Spotted hyenas live in clans, the size of which depends on the abundance of prey and may vary from only a few individuals to more than a hundred. Life in the clan can be difficult for lower-ranked individuals. They may be excluded and may not get access to food.
"Rank is super important," says Dr. Akçay, who co-authored the study. "Spotted hyena live in a matriarchal society. Those born to a lower-ranked mother are less likely to survive and to reproduce." Descendants of high-class individuals face fewer constraints than descendants of lower-class individuals in choosing their social partners. The researchers found that offspring born to high-ranked mothers copied their mother's bonds more accurately than those born to low-ranked mothers.
Social inheritance plays an important role in survival, and the researchers discovered an association between the two in both mothers and female offspring. There was a positive relationship between offspring survival and social associations that were similar to their mothers, but only in offspring of high-ranked mothers. Mothers of offspring who were more similar to them in social association were more likely to survive to the following year, possibly reflecting a change in maternal relationships as they get older.
The results of this study suggest that social inheritance plays an important role in building the social networks of hyenas and further supports Ilany's and Akçay's hypothesis that in species with stable social groups, the inheritance of social connections from parents is the cornerstone of social structure. In several species successful social integration is associated with higher survival and reproductive success. The results add to this by showing that social inheritance is also associated with both offspring and mother survival.
The researchers note that social network inheritance likely contributes to a group's stability, and also has implications for how behaviors are learned and spread through groups. The study also underscores how factors other than genetics hold sway in key evolutionary outcomes, including reproductive success and overall survival. "A lot of things that are considered by default to be genetically determined may depend on environmental and social processes," concludes Ilany.
CAPTION
A massive study of data collected over 27 years, published today in the journal Science, sheds new light on social networks, rank and survival of spotted hyenas.
Dr. Amiyaal Ilany, a biologist at Bar-Ilan University in Israel, integrates behavioral ecology, network science, and social science, to study broad aspects of social behavior in the wild. As a postdoctoral researcher at the University of Pennsylvania, he developed, together with Dr. Erol Akçay, a theoretical model suggesting that social inheritance - in which offspring inherit their social bonds from their parents, either passively or by copying them - could explain the social networks of multiple species. To test their model Ilany and Akçay forged a partnership with Dr. Kay Holekamp, of Michigan State University. Holekamp had spent the previous 27 years observing wild spotted hyenas in Kenya.
Poring over Holekamp's data, which included nearly 74,000 social interactions among the spotted creatures, they were able to show, for the first time on such a large scale, that their model correctly hypothesized that a process of social inheritance determines how offspring relationships are formed and maintained. Their study also elucidates the major role that social rank plays in structuring the spotted hyena clan, and how this affects survival.
CREDIT
Lily Johnson-Ulrich
Pandemic of antibiotic resistance is killing children in Bangladesh
BOSTON - Resistance to antibiotics is common and often deadly among children with pneumonia in Bangladesh, according to a new study coauthored by researchers from Massachusetts General Hospital (MGH) with colleagues at the International Centre for Diarrhoeal Disease Research, Bangladesh (abbreviated as icddr,b). This study, which appears in the journal Open Forum Infectious Diseases, offers an early warning that a pandemic of potentially deadly antibiotic resistance is under way and could spread around the globe.
The study was led by Mohammod Jobayer Chisti, MD, PhD, a senior scientist in icddr,b's Nutrition and Clinical Services Division. Chisti was inspired to conduct the research when he observed that the hospital affiliated with icddr,b was admitting more and more young children with pneumonia who were highly resistant to treatment with standard antibiotics. "At our hospital, dozens of kids died of pneumonia between 2014 and 2017, despite receiving the World Health Organization's recommended antibiotics and enhanced respiratory support," says Chisti.
Pneumonia is an infection of the lungs that causes fluid and pus to fill air sacs, producing cough, fever, trouble breathing, and other symptoms. Without effective treatment, the infection can be fatal; pneumonia is the most common cause of death in young children, according to the World Health Organization. In small children, pneumonia can be caused by viruses, but certain types of bacteria are common sources of infection, too. In the United States and other high-income countries, Staphylococcus ("staph"), Streptococcus ("strep"), and Haemophilus influenzae are the most common bacterial causes of pneumonia, which usually respond well to antibiotic therapy. Vaccines for the latter two have saved countless lives worldwide.
However, when Chisti and his colleagues examined health records of more than 4,000 children under age five with pneumonia admitted to their hospital between 2014 and 2017, they found that a very different pattern of bacterial infections was occurring. The usual staph and strep infections that commonly cause pneumonia in the United States and elsewhere were relatively rare. Among the children who had a positive culture, gram-negative bacteria were responsible for 77 percent of the infections, including Pseudomonas, E. coli, Salmonella and Klebsiella.
"That's totally different than what I'm used to in my practice in Boston," says Jason Harris, MD, MPH, co-first author of the study and chief of the division of Pediatric Global Health at the Massachusetts General Hospital for Children. Unfortunately, he adds, "the gram-negative bacteria we saw in these kids are notorious for being antibiotic resistant." To wit: Some 40 percent of the gram-negative bacterial infections in this study resisted treatment with first- and second-line antibiotics that are routinely used to treat pneumonia. More alarming, children who had antibiotic-resistant bacterial infections were 17 times more likely than others without bacterial infections to die.
Harris believes that these results are clear evidence that longstanding concerns that antibiotic resistance will become a deadly menace are no longer theoretical--the problem has taken root. "These kids are already dying early because of antibiotic-resistant bacteria, from what would be a routine infection in other parts of the world," says Harris. "And this was at one hospital in Bangladesh. Extrapolate these findings across a country of 163 million people, and then to a larger region where antibiotic resistance is emerging, and the overall numbers are probably huge."
There is an urgent need to address factors that are promoting antibiotic resistance in Bangladesh, says Tahmeed Ahmed, PhD, executive director of icddr,b and senior author of the study. For starters, antibiotics can be purchased without a prescription in the country and many people use them to self-treat conditions such as dysentery, cold, cough and fever. Misuse of antibiotics promotes the spread of bacteria that resist the medications. "We may be able to reduce this emerging bacterial resistance by improving antibiotic stewardship, particularly in the outpatient setting," says Ahmed. Lab testing for diagnosis of bacterial infections is also inadequate in the country. "What's more, lack of access to clean water and adequate sanitation helps spread bacteria that are resistant to antibiotics," adds Ahmed. Improvements in health care infrastructure and policy changes to rein in the misuse of antibiotics are essential, he argues, though Ahmed notes that Bangladesh's health care system also needs better access to more advanced antibiotic therapies for resistant infections.
If these and other steps aren't taken now, it's only a matter of time before the problem of widespread deadly antibiotic resistance spreads around the world, notes Harris. "We know that acquisition of antibiotic resistance is very common in travelers, and that when highly resistant bacteria crop up in one part of the world, they ultimately crop up everywhere," he says, comparing the problem to another current global health care crisis. "If COVID-19 was a tsunami, then emerging antibiotic resistance is like a rising flood water. And it's kids in Bangladesh who are already going under."
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Harris is also an associate professor of pediatrics at Harvard Medical School.
This research was funded by unrestricted support to icddr,b from the governments of Bangladesh, Canada, Sweden and the United Kingdom. Harris receives funding from the National Institutes of Health.
About the Massachusetts General Hospital
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In August 2020, Mass General was named #6 in the U.S. News & World Report list of "America's Best Hospitals."
About icddr,b
icddr,b, formerly known as International Centre for Diarrhoeal Disease Research, Bangladesh is an international public health research institution based in Bangladesh. Established in 1960, icddr,b has been at the forefront of discovering low cost solutions to key public health challenges facing people in poverty and provides robust evidence of their effectiveness at a large scale. Instrumental in the development of oral rehydration therapy, icddr,b's research in this area has been credited with saving more than 70 million lives worldwide. From an early focus on cholera and diarrhoeal disease, the scope has expanded to encompass most of the global public health challenges. Find out more at http://www.icddrb.org or follow @icddr_b
Roadless forests see more blazes and greater severity, but fire resilience is the result
IMAGE: BEACHIE CREEK FIRE 2020 WHEN IT WAS STILL SMALL. view more
CREDIT: (PHOTO BY JAMES JOHNSTON, OSU COLLEGE OF FORESTRY)
CORVALLIS, Ore. - Roadless national forests in the American West burn more often and at a slightly higher severity than national forests with roads, but the end result for the roadless forests is greater fire resilience, Oregon State University researchers say.
The findings, published today in Environmental Research Letters, provide a key piece of the puzzle for a region trying to develop better approaches to living with fire in the wake of a 2020 fire season that brought historically disastrous blazes.
Limiting smoke exposure and reducing risk to water supplies, habitat and human infrastructure from huge, uncontrolled fires are important goals of policymakers, said James Johnston, a researcher in the OSU College of Forestry and the study's leader.
Mechanical fuel treatments - piling brush, thinning dense stands of trees, etc. - are a common tool for meeting those goals, but more than half of all fires, including most of the largest ones, burn mainly in roadless areas, where mechanical treatments are usually prohibited.
"The extent of fire where management options are limited makes clear the need to adapt to, rather than overcome, fire," he said.
Differences in fire extent and fire escape - a fire getting beyond the area you think it should stay contained in - are strongly associated with roadless vs. non-roadless management, Johnston said. But the real drivers of fire severity - i.e. tree mortality - are differences in environment and not land use designations.
Trees growing in sites at higher elevations with greater moisture availability and lower temperatures - which describes most of the roadless sites - are generally less fire tolerant than species found in drier, lower-elevation landscapes.
Created in 1905, the U.S. Forest Service oversees nearly 190 million acres of national forests, most of it in the West. The area managed by the USFS makes up one-fifth of all forestland in the United States and 1.5% globally.
Historically, federal legislation typically required the agency to emphasize timber cutting, but the Wilderness Act of 1964 called for the creation of areas where natural conditions would be preserved.
"The act also required the Forest Service to inventory all of its roadless areas not designated as wilderness, pending future action by Congress," Johnston said. "Any of those roadless areas not released for development in the 1970s and '80s ended up becoming an unofficial extension of the wilderness system, and then in 2001, the Roadless Area Conservation Rule generally prohibited building roads and harvesting timber in those areas."
That created two distinct management regimes: an active one featuring road-filled landscapes and a history of recreational development and timber harvesting, and another with no roads, no development and little or no harvesting history. The breakdown is roughly 50-50.
"Human influences are largely absent in roadless areas, the management of which is largely a matter of decisions about how to deal with natural disturbances like wildfire," Johnston said.
Before 1910, frequent low-severity surface fires played a key role in maintaining forests. In the decades since, the comparative lack of fire that resulted from federal policy - in concert with grazing, logging and land-use changes - have caused major structural shifts in older forests as shade-tolerant and fire-intolerant species have moved in.
The policy of fire suppression traces its roots to the Great Fire of 1910, which killed 87 people, destroyed several towns and burned an area roughly the size of Connecticut. The blaze consumed 3 million acres of forest in Idaho, Montana, Washington and British Columbia.
"Wildfire is an important disturbance process that shapes the structure, composition and function of forests, and a better understanding of how passive versus active management relates to fire patterns is critical for managers trying to meet new objectives to restore forests to their natural fire regime," Johnston said. "Over the last three decades, roughly one-third of the roadless landscape experienced fire, while less than one-fifth of the 'roaded' lands did."
That's despite the fact that roadless areas had far fewer ignition events and are generally in regions that are cooler and moister.
"Most of the largest fires that have burned on national forestland in recent years began in roadless areas," said study co-author Jack Kilbride, a Ph.D. student in OSU's College of Earth, Ocean and Atmospheric Sciences. "But evidence suggests that the greater extent of fire in roadless areas has potential to make those landscapes more resilient in the face of climate change. This study really shows the usefulness of satellite data for being able to characterize how fire patterns differ as a function of management."
The legacy of fire suppression includes increased forest density, shifts in species composition and loss of resiliency to fire, drought and insects, the researchers say. But a number of recent studies have shown that forests in wilderness and other roadless areas that have experienced multiple fires are less likely to experience stand-replacing fire and are getting back to the structure and composition they featured prior to white settlement.
"Mechanical thinning, prescribed fire and wildland fire will continue to be used as tools on the 'roaded' landscape," Johnston said. "And without major policy changes, wildland fire will continue to be the primary weapon available in roadless areas. Working together, forest managers and scientists can determine which management objectives are seeing progress, and how much."
