The rat's whiskers: multidisciplinary research reveals how we sense texture

Mathematicians and neuroscientists achieve breakthrough in understanding how whiskers 'amplify' texture

UNIVERSITY OF BRISTOL

Research News

 

IMAGE: THE TAPERING OF THE WHISKER HAS THE EFFECT OF AMPLIFYING TINY HIGH-FREQUENCY MOTIONS INTO APPRECIABLE PULSE-LIKE CHANGES IN FORCES AND MOVEMENT AT THE WHISKER FOLLICLE. view more 

CREDIT: NATURE SCIENTIFIC REPORTS

How we sense texture has long been a mystery. It is known that nerves attached to the fingertip skin are responsible for sensing different surfaces, but how they do it is not well understood. Rodents perform texture sensing through their whiskers. Like human fingertips, whiskers perform multiple tasks, sensing proximity and shape of objects, as well as surface textures.

Mathematicians from the University of Bristol's Department of Engineering Mathematics, worked with neuroscientists from the University of Tuebingen in Germany, to understand how the motion of a whisker across a surface translates texture information into neural signals that can be perceived by the brain.

By carrying out high precision laboratory tests on a real rat whisker, combined with computation models, the researchers found that whiskers act like antennae, tuned to sense the tiny stick-slip motions caused by friction between the surface and the tip of the whisker.

"One of the most striking things we found both in the experiments and the theory was the thousand-fold amplification of tiny force signals perceived by the tip of the whisker to that received by the neurons at the whiskers base. Suddenly we realised that the whisker is acting like an amplifier, taking micro-scale stick-slip events and rapidly turning them into clean pulses that can be picked up and processed by the brain," said Professor Alan Champneys from the University of Bristol, co-lead of the modelling work with colleague, Dr Robert Szalai. Dr Thibaut Putelat carried out the detailed numerical modelling.

The research Conveyance of texture signals along a rat whisker, published in the journal Scientific Reports from the publisher Nature, reveals the tapering of the whisker has the effect of amplifying tiny high-frequency motions into appreciable pulse-like changes in forces and movement at the whisker follicle. In turn, the nerve cells in the follicle sense these changes and transmit them to the brain.

"It is almost as if the morphology of the whisker is designed to convey these friction-induced signals as "AC" waves on top of the "DC" motion of the whisker that conveys the information on surface proximity and hardness.

"These AC waves are too small and too rapid to be perceived by the human eye. However, in approaching this problem in a multidisciplinary fashion, we have been able to reveal these waves with clarity for the first time," said Professor Champneys.

"The findings have implications for human touch too, where the morphology of finger-print ridges is more complex, but might similarly distinguish between AC and DC signals as our brain tries to disentangle multiple information streams about what we are feeling," said Dr Maysam Oladazimi, who carried out the experiments as part of his PhD.

The findings could have far-reaching benefits including how textures could be designed to provide optimal cues for the visually impaired, for human safety operation in low light environments, or for immersive artistic installations.

"This research opens several avenues for future work. As neuroscientists, we are interested in developing a more detailed understanding of neural signalling pathways in texture discrimination, while our colleagues in Bristol are keen to explore implications for the design of future robotic sensing systems," said Professor Cornelius Schwarz, who led the experiments at the University of Tuebingen.

Professor Champneys said the research was of particular value to haptic-sensing in the field of robotics, where robots literally feel their environment and is the focus of much current research, especially for robots that need to act autonomously in the dark, such as in search and rescue missions. Professor Nathan Lepora and colleagues at the Bristol Robotics Laboratory are pioneers in this field.

"This transnational interdisciplinary collaboration between experimentalists and mathematical modellers was exciting. The results from the computer models and from the laboratory experiments went hand in hand - it was only through a combination of the two that we were able to make our breakthrough," said Professor Champneys.

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Paper:

Conveyance of texture signals along a rat whisker, by Oladazimi, M; Putelat, T; Szalai, R; Noda, K; Shimoyama, I; Champneys, A & Schwarz, C; published in Scientific Reports. 11, 13570 (2021). https://doi.org/10.1038/s41598-021-92770-3

 OF MICE AND MEN

Combining plant-based diet and a healthy microbiome may protect against multiple sclerosis

Metabolism of isoflavone by gut bacteria protects mice from MS-like inflammation

UNIVERSITY OF IOWA HEALTH CARE

Research News

A new University of Iowa study suggests that metabolism of plant-based dietary substances by specific gut bacteria, which are lacking in patients with multiple sclerosis (MS), may provide protection against the disease.

The study led by Ashutosh Mangalam, PhD, UI associate professor of pathology, shows that a diet rich in isoflavone, a phytoestrogen or plant-based compound that resembles estrogen, protects against multiple sclerosis-like symptoms in a mouse model of the disease. Importantly, the isoflavone diet was only protective when the mice had gut microbes capable of breaking down the isoflavones. The findings were published July 9 in Science Advances.

"Interestingly, previous human studies have demonstrated that patients with multiple sclerosis lack these bacteria compared to individuals without MS," Mangalam says. "Our new study provides evidence that the combination of dietary isoflavones and these isoflavone metabolizing gut bacteria may serve as a potential treatment for MS."

Isoflavones are found in soybeans, peanuts, chickpeas and other legumes. The study also found that mice fed the isoflavone diet have a microbiome that is similar to the microbiome found in healthy people and includes the bacteria which can metabolize isoflavones. Conversely, a diet lacking isoflavones promotes a microbiome in mice which is similar to one observed in patients with MS and lacks beneficial bacteria that can metabolize isoflavone.

Multiple sclerosis is an autoimmune disease of the brain and spinal cord where the immune system attacks the protective coating surrounding nerve fibers. The symptoms of this disease include muscles weakness, balance issues, and problems with vision and thinking. While there are treatments that slow down the disease, there is currently no cure for MS.

Although the exact cause of MS is unknown, a complex interaction between genetic and environmental factors are thought to initiate the disease. Recently, the gut microbiome--the trillions of gut bacteria the live inside human intestines--has emerged as a potential environmental factor that contributes to MS. In prior work, Mangalam and colleagues demonstrated that there are significant differences between the gut microbes of patients with MS and people without MS. Specifically, patients with MS lacked bacteria that are able to metabolize isoflavones. Although role of gut microbiome in human diseases such as MS is being appreciated, the mechanism through which these gut bacteria might influence the disease is poorly understood.

In the current study, Mangalam's team, including first author Samantha Jensen, a UI graduate student in immunology, found that the bacteria that are lacking in patients with MS are able to suppress inflammation in a mouse model of MS. The team compared the effects of an isoflavone diet and an isoflavone-free diet on disease in the mouse model of MS. They found that the isoflavone diet led to disease protection. However, when the team placed the mice on the isoflavone diet but removed the isoflavone-metabolizing gut bacteria, the isoflavone diet was no longer able to protect against MS-like symptoms. When the bacteria were reintroduced, the protective effect of the isoflavone diet was restored. Furthermore, the team was able to show that a specific isoflavone metabolite called equol, which is produced by the gut bacteria from isoflavone, is also able to provide protection against disease.

"This study suggests that an isoflavone diet may be protective so long as the isoflavone metabolizing gut bacteria are present in the intestines," say Mangalam, who also is a member of the Iowa Neuroscience institute and Holden Comprehensive Cancer Center.

###

The research was supported in part by the National Multiple Sclerosis Society, the National Institute of Allergy and Infectious Diseases, the National Institute of Environmental Health Sciences, and the Roy J. Carver Charitable Trust.

In addition to Mangalam and Jensen, the team included UI scientists Shailesh Shahi and Stephanie Peterson; Katherine Gibson-Corley at Vanderbilt University; Nicole Cady at the University of Michigan; and Arnav Gupta at the KK Birla in Goa.

 

Empathy may drive rats and other mammals to help friends over strangers

A new study identifies the brain regions involved in rats' tendency to help members of their own social group over strangers, with findings that may help scientists better understand similar social biases in humans

ELIFE

Research News

 

IMAGE: NEW FINDINGS REVEAL THAT RATS FEEL EMPATHY FOR OTHER RATS, BUT REFRAIN FROM HELPING THOSE OUTSIDE THEIR SOCIAL GROUP. view more 

CREDIT: INBAL BEN-AMI BARTAL (CC BY 4.0)

Rescuing a member of their own social group, but not a stranger, triggers motivational and social reward centres in rats' brains, suggests a report published today in eLife.

The study provides the first description of similar brain activity in both rats and humans underlying this socially biased behaviour. The findings add to our understanding of social biases and could help with developing ways to promote cooperation outside of an individual's social group.

"Humans, as well as many other creatures, are biased toward helping other members of their social groups over individuals they view as outsiders, and this can have a negative impact in diverse societies where different groups need to cooperate in order to thrive," says first author Inbal Ben-Ami Bartal, a faculty member at the Sagol School of Neuroscience and the Psychology Department at Tel-Aviv University, Israel. "Understanding the brain mechanisms underlying these biases is essential to finding ways to eliminate them."

To explore this further, Bartal and a multinational team of colleagues placed rats in a situation where either a cage mate of the same type of rat, or a different type of rat they had never met, was trapped. In the experiments, most rats learned to free their cage mate, but few rescued the stranger.

The team then examined the brain activity associated with these behaviours to understand why the rats were biased towards helping their cage mates. They found that some regions of the brain are activated in response to the distress of either a cage mate or an unfamiliar rat, meaning that rats sense the distress of another animal whether or not they know them. But additional brain regions associated with reward seeking and positive social experiences were turned on only when a cage mate was in distress. "This brain activity in the rats that helped their fellow group members suggests an empathetic response to their distress," Bartal says.

Previous studies in humans have also suggested that empathy towards fellow group members drives the desire to help them but not strangers. The current findings suggest that similar brain activity may drive these social biases in rats and potentially other mammals.

"We've provided the first evidence for a common biological mechanism driving empathic helping behaviours in humans and rats in response to the distress of friends," concludes senior author Daniela Kaufer, Professor at the Department of Integrative Biology and the Helen Wills Neuroscience Institute at the University of California, Berkeley, US. "Our results lay the groundwork for future studies to better understand the brain activity involved and why it causes us to choose helping some people over others."

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About eLife

eLife is a non-profit organisation created by funders and led by researchers. Our mission is to accelerate discovery by operating a platform for research communication that encourages and recognises the most responsible behaviours. We aim to publish work of the highest standards and importance in all areas of biology and medicine, including Neuroscience, while exploring creative new ways to improve how research is assessed and published. eLife receives financial support and strategic guidance from the Howard Hughes Medical Institute, the Knut and Alice Wallenberg Foundation, the Max Planck Society and Wellcome. Learn more at https://elifesciences.org/about.

To read the latest Neuroscience research published in eLife, visit https://elifesciences.org/subjects/neuroscience.

 

Are silver nanoparticles a silver bullet against microbes?

Leanne Gilbertson's group studies the mechanisms behind bacterial resistance to silver nanoparticles to determine if their ubiquitous use is a solution to the antimicrobial resistance challenge or if it is perhaps fueling the fire

UNIVERSITY OF PITTSBURGH

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IMAGE: A DEPICTION OF HYPER-MOTILE E.COLI, A STRAIN OF BACTERIA FOUND TO RESIST SILVER NANOPARTICLES' ANTIMICROBIAL PROPERTIES AFTER REPEATED EXPOSURE. view more 

CREDIT: LISA STABRYLA/UNIVERSITY OF PITTSBURGH.

Antimicrobials are used to kill or slow the growth of bacteria, viruses and other microorganisms. They can be in the form of antibiotics, used to treat bodily infections, or as an additive or coating on commercial products used to keep germs at bay. These life-saving tools are essential to preventing and treating infections in humans, animals and plants, but they also pose a global threat to public health when microorganisms develop resistance to them, a concept known as antimicrobial resistance.

One of the main drivers of antimicrobial resistance is the misuse and overuse of antimicrobial agents, which includes silver nanoparticles, an advanced material with well-documented antimicrobial properties. It is increasingly used in commercial products that boast enhanced germ-killing performance - it has been woven into textiles, coated onto toothbrushes, and even mixed into cosmetics as a preservative.

The Gilbertson Group at the University of Pittsburgh Swanson School of Engineering used laboratory strains of E.coli to better understand bacterial resistance to silver nanoparticles and attempt to get ahead of the potential misuse of this material. The team recently published their results in Nature Nanotechnology.

"Bacterial resistance to silver nanoparticles is understudied, so our group looked at the mechanisms behind this event," said Lisa Stabryla, lead author on the paper and a recent civil and environmental PhD graduate at Pitt. "This is a promising innovation to add to our arsenal of antimicrobials, but we need to consciously study it and perhaps regulate its use to avoid decreased efficacy like we've seen with some common antibiotics."

Stabryla exposed E.coli to 20 consecutive days of silver nanoparticles and monitored bacterial growth over time. Nanoparticles are roughly 50 times smaller than a bacterium.

"In the beginning, bacteria could only survive at low concentrations of silver nanoparticles, but as the experiment continued, we found that they could survive at higher doses," Stabryla noted. "Interestingly, we found that bacteria developed resistance to the silver nanoparticles but not their released silver ions alone."

The group sequenced the genome of the E.coli that had been exposed to silver nanoparticles and found a mutation in a gene that corresponds to an efflux pump that pushes heavy metal ions out of the cell.

"It is possible that some form of silver is getting into the cell, and when it arrives, the cell mutates to quickly pump it out," she added. "More work is needed to determine if researchers can perhaps overcome this mechanism of resistance through particle design."

The group then studied two different types of E.coli: a hyper-motile strain that swims through its environment more quickly than normally motile bacteria and a non-motile strain that does not have physical means for moving around. They found that only the hyper-motile strain developed resistance.

"This finding could suggest that silver nanoparticles may be a good option to target certain types of bacteria, particularly non-motile strains," Stabryla said.

In the end, bacteria will still find a way to evolve and evade antimicrobials. The hope is that an understanding of the mechanisms that lead to this evolution and a mindful use of new antimicrobials will lessen the impact of antimicrobial resistance.

"We are the first to look at bacterial motility effects on the ability to develop resistance to silver nanoparticles," said Leanne Gilbertson, assistant professor of civil and environmental engineering at Pitt. "The observed difference is really interesting and merits further investigation to understand it and how to link the genetic response - the efflux pump regulation - to the bacteria's ability to move in the system.

"The results are promising for being able to tune particle properties for a desired response, such as high efficacy while avoiding resistance."

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Mosquito-resistant clothing prevents bites in trials

NORTH CAROLINA STATE UNIVERSITY

Research News

North Carolina State University researchers have created insecticide-free, mosquito-resistant clothing using textile materials they confirmed to be bite-proof in experiments with live mosquitoes. They developed the materials using a computational model of their own design, which describes the biting behavior of Aedes aegypti, the mosquito that carries viruses that cause human diseases like Zika, Dengue fever and yellow fever.

Ultimately, the researchers reported in the journal Insects that they were able to prevent 100 percent of bites when a volunteer wore their clothing - a base layer undergarment and a combat shirt initially designed for the military - in a cage with 200 live, disease-free mosquitoes. Vector Textiles, an NC State startup company, has licensed the related patent rights and intends to make clothing for commercial sale in the United States.

The researchers think their computational model could be used more widely to develop clothing to reduce transmission of diseases.

"The fabric is proven to work - that's the great thing we discovered," said study co-author Andre West, associate professor of fashion and textile design at NC State and director of Zeis Textiles Extension for Economic Development. "To me, that's revolutionary. We found we can prevent the mosquito from pushing through the fabric, while others were thick enough to prevent it from reaching the skin."

To develop the computational model to design textile materials that could prevent A. aegypti bites, researchers investigated the dimensions of the head, antenna and mouth of A. aegypti, and the mechanics of how it bites. Then, they used the model to predict textile materials that would prevent bites, depending on their thickness and pore size. Researchers said they believe the materials could be effective against other mosquito species in addition to A. aegypti because of similarities in biology and biting behavior.

"There are different uses for clothing," said the study's first author Kun Luan, postdoctoral research scholar of forest biomaterials at NC State. "The idea is to have a model that will cover all possible garments that a person would ever want."

To test the accuracy of their model, the researchers tested the materials predicted to be bite-proof. In experiments with live, disease-free mosquitoes, the researchers surrounded a blood reservoir with plastic materials made according to parameters predicted by the model. They then counted how many mosquitoes became engorged with blood.

One material they initially tested was very thin - less than one millimeter thick - but had a very small pore size to prevent the mosquito from sticking its mouth parts, or proboscis, through the material. Another material had a medium pore size to prevent the mosquito from inserting its head through the textile far enough to reach the skin; and a third material had larger pores, but was sufficiently thick that the mosquito's mouth still couldn't reach the skin.

In a subsequent test, the researchers chose a series of knitted and woven fabrics that met the bite-proof parameters determined by the model, and validated they worked in experiments using both the blood reservoir and human volunteers. The researchers tested the number of bites received by volunteers when study participants inserted an arm covered by a protective sleeve into a mosquito cage. The researchers also compared the fabrics' ability to prevent bites and repel mosquitoes to fabrics treated with an insecticide.

From what they learned in early experiments, researchers developed the bite-resistant, form-fitting undergarment made with a thin material, as well as a long-sleeved shirt, which was initially envisioned as a combat shirt for the military.

When a volunteer wore the garments sitting for 10 minutes and standing for 10 minutes in a walk-in cage with 200 hungry mosquitos, the volunteer found the combat shirt was 100 percent effective at preventing bites. In the first trial testing the base layer, the volunteer received bites on the back and shoulders - seven bites for 200 mosquitoes. The researchers attributed the bites to the fabric stretching and deforming, so they doubled the material layer around the shoulders, and were ultimately able to prevent 100 percent of bites. They also tested the clothing for comfort, and to see how well it trapped heat and released moisture.

"The final garments that were produced were 100 percent bite-resistant," said Michael Roe, William Neal Reynolds Distinguished Professor of Entomology at NC State. "Everyday clothing you wear in the summer is not bite-resistant to mosquitoes. Our work has shown that it doesn't have to be that way. Clothes that you wear every day can be made bite-resistant. Ultimately, the idea is to have a model that will cover all possible garments that person would ever want - both for the military as well as for private use."

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The study, "Mosquito-textile physics: A mathematical roadmap to insecticide-free, bite-proof clothing for everyday life," was published online July X, 2021, in the journal Insects. It was authored by Luan, Roe, West, Charles Apperson, Marian McCord, Emiel DenHartog, Quan Shi, Nicholas Travanty, Robert Mitchell, Grayson Cave, John Strider and Youngxin Wang from NC State University and Isa Bettermann, Florian Neumann and Tobias Beck from Aachen University, Germany. The study was supported by the National Science Foundation, the Department of Defense Deployed War Fighter Program, Natick Contracting Division of the U.S. Department of Defense, the Chancellor's Innovation Fund at NC State, the Southeast Center for Agricultural Health and Injury Prevention, PILOTS and the NC Agriculture Research Experiment Station.

Note to editors: The abstract follows.

"Mosquito-textile physics: A mathematical roadmap to insecticide-free, bite-proof clothing for everyday life"

Authors: Kun Luan, Andre J. West, Marian G. McCord, Emiel DenHartog, Quan Shi, Isa Bettermann, Jiayin Li, Nicholas V. Travanty, Robert D. Mitchell III, Grayson L. Cave, John B. Strider, Yongxin Wang, Florian Neumann, Tobias Beck, Charles S. Apperson and R. Michael Roe.

Published online in Insects on July 13, 2021.

DOI: 10.3390/insects12070636

Abstract: Garments treated with chemical insecticides are commonly used to prevent mosquito bites. Resistance to insecticides, however, is threatening the efficacy of this technology, and people are increasingly concerned about the potential health impacts of wearing insecticide-treated clothing. Here, we report a mathematical model for fabric barriers that resist bites from

Aedes aegypti mosquitoes based on textile physical structure and no insecticides. The model was derived from mosquito morphometrics and analysis of mosquito biting behavior. Precision polypropylene plates were first used to simulate woven and knitted fabrics for model validation.

Then based on model predictions, prototype knitted textiles and garments were developed that prevented mosquito biting and were tested for comfort. Our predictive model can be used to develop additional textiles in the future for garments that are highly bite-resistant to mosquitoes.

Disclaimer: AAAS and

 

Study: Racial/ethnic and language inequities in ways patients obtain COVID-19 testing

UNIVERSITY OF MINNESOTA

Research News

The COVID-19 pandemic caused an unprecedented disruption to health care delivery, with resources shifted toward telehealth services and mass viral testing. While early studies in the pandemic highlighted differences in health care utilization among patients with commercial insurance, data from publicly insured or uninsured "safety-net" patient populations continue to emerge.

A recent study from researchers at the University of Minnesota and Hennepin Healthcare Research Institute (HHRI) is among the first to examine how different socio-demographic groups used telehealth, outpatient (i.e., clinic), emergency department and inpatient (i.e., hospital) care to test for SARS-CoV-2, the virus that causes COVID-19. Their findings were recently published in JAMA Network Open.

The study was led by U of M School of Public Health graduate student Rohan Khazanchi. Along with others from Hennepin Healthcare and HHRI, researchers included Medical School Assistant Professor Tyler Winkelman, who is also with the U of M Robina Institute of Criminal Law and Criminal Justice, and HHRI Data Scientist Peter Bodurtha. The team analyzed anonymous electronic health record data for people with symptoms of viral illness who received SARS-CoV-2 testing at Hennepin Healthcare, a large safety-net health system in Minneapolis.

The study found that:

• Patients who initiated testing via telehealth were disproportionately white and English-speaking, whereas patients who initiated testing through the emergency department were disproportionately Black, Native American, non-English-speaking and had one or more pre-existing conditions.
• Testing initiated through telehealth and outpatient encounters was associated with lower rates of subsequent inpatient and intensive care unit care than testing initiated in more care-intensive settings, such as emergency departments.

"Inequities by race, ethnicity and language in where people seek SARS-CoV-2 testing may point to several structural root causes, including barriers to timely testing access, delays in care seeking, difficulty accessing telehealth services, and higher rates of pre-existing conditions among patients who require higher levels of care," said Khazanchi.

The researchers also added that the inequities could be partially explained by clinician and clinic variations in telehealth use.

"Without structural reforms, rapid implementation of telehealth and other new services may exacerbate inequities in access to care, particularly if these investments come at the expense of other care sites," said Bodurtha.

The authors said that as investigators explore the effects of the COVID-19 pandemic on health use and patient outcomes, future research should continue to examine how and why the health care use of safety-net patients differs from commercially insured individuals to inform equity-oriented interventions.

The study was supported by the National Institutes of Health's National Center for Advancing Translational Sciences (#UL1TR002494).

 STRUCTURAL RACISM

US-wide, non-white neighborhoods are hotter than white ones

Wealthier, whiter urban and small-town residents benefit more from cooling infrastructure and trees

AMERICAN GEOPHYSICAL UNION

Research News

 

IMAGE: THE INTERACTIVE MAP SHOWS THE WIDESPREAD RACE AND CLASS DISPARITIES IN EXTREME SUMMER SURFACE TEMPERATURES ACROSS THE UNITED STATES. THIS MAP ONLY SHOWS COUNTIES WITH MORE THAN 10 CENSUS TRACTS. view more 

CREDIT: SUZANNE BENZ

WASHINGTON--In cities and towns across the United States, neighborhoods with more Black, Hispanic and Asian residents experience hotter temperatures during summer heatwaves than nearby white residents, a new study finds. It is the first to show that the trend, documented in some major cities, is widespread, even in small towns, nationwide.  

According to the new nationwide study, these racial disparities exist because non-white neighborhoods tend to be more densely built up with buildings and pavement that trap heat and have fewer trees to cool the landscape.   

"Urban climate is different from temperatures outside the city," said co-author Susanne Benz, an environmental scientist who conducted this research at the University of California, San Diego, and is now at Dalhousie University. "Inside the city, temperatures are affected by the buildings surrounding you and by the surface of the streets." Dark pavement absorbs sunlight and releases the heat at night, while trees and other vegetation cool an area through transpiration, when they release water vapor through pores in the leaves.  

The new study is published in Earth's Future, AGU's journal for interdisciplinary research on the past, present and future of our planet and its inhabitants. The approach offers city planners and policymakers a way to identify disparities and to evaluate initiatives to address urban heat.    

Summer in the city

Summer heatwaves cause more than 700 deaths each year in the United States. When heat and humidity are so high that a body can no longer cool itself through sweating, heat stroke can set in, rapidly causing brain and organ damage. People who are older, have certain chronic health conditions or are physically exerting themselves are most at risk. Urban environments are commonly hotter than their rural counterparts, and temperatures can vary even within cities. Those few degrees can mean life or death for some residents.

Benz initially had the idea for this study after reading a New York Times article finding that neighborhoods the U.S. government redlined in the 1930s--meaning they classified them as poor investments because people of color lived there--are now hotter than white neighborhoods in the same cities. She and co-author Jennifer Burney, an Earth scientist at the University of California, San Diego, realized they could do a similar analysis for the entire country.   

Benz looked for urban heat patterns using land surface temperatures during summer heat waves collected by a NASA satellite. She subtracted the temperature of nearby rural locations to find variations in urban heat across towns and cities. Then she combined the temperature data with demographic information from the U.S. Census, looking at more than 1,000 counties to see who was most impacted. NOAA and USGS survey data allowed her to estimate how densely built up an area was, and the proportion of land covered by trees.  

The researchers found that in 76% of counties with more than 10 census tracts, poorer neighborhoods were notably hotter than wealthier ones, primarily due to physical differences--more pavement and people and fewer trees. Areas with a larger percentage of people of color or where people had less education also experienced higher temperatures.  

Big cities weren't the only places with race-related heat differences. Benz and Burney also saw the same patterns playing out in less developed areas. "It turns out that even your tiny towns have the same disparities," Benz said, "and this was something that really shocked me."  

The trend held up even when they took wealth out of the picture. When residents had a similar income, non-white neighborhoods still faced significantly higher temperatures than white ones in 71% of the counties.    

"The findings are really quite staggering," said Jeremy Hoffman, a climate scientist and chief scientist at the Science Museum of Virginia, who was not involved in the research. "These disparities exist across virtually every built environment in the country. Money doesn't grow on trees, but it is certainly concentrated underneath them across the U.S." 

How to beat urban heat  

The new analysis provides information for policymakers and establishes a way to evaluate the success of policies designed to address urban heat. "There's a lot of talk in Biden's administration about environmental justice but not so much clarity on what metrics might be used to evaluate policy proposals," said Burney. "These are very concrete metrics that can be tracked over time."  

Now that officials can recognize and measure urban heat disparities, the big question is how to fix them.   

Hoffman thinks it will take thoughtful investment to cool off hotter neighborhoods, such as planting trees at parks, bus stops and along pedestrian thoroughfares and providing incentives for green or white reflective roofs to cool buildings. These initiatives could dovetail with urban agriculture programs, solar panel installation, workforce development and other programs to more holistically address racial inequality.   

Benz hopes that this analysis will be useful for all communities, but especially for smaller towns, whose residents can use the information to understand where disparities exist and take steps to correct them--before they become entrenched through further urbanization. She created a website where interested users can visualize where heat extremes exist in their area. 

Daytime urban surface temperature (IMAGE)

AMERICAN GEOPHYSICAL UNION

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CAPTION

Higher temperatures correspond to regions of the United States with more poor, non-white residents, including this example of extreme summer daytime urban surface temperature anomalies (left), lower median income (center) and share of non-Hispanic white residents (right) from western Washington State, with King County and the greater Seattle metropolitan area at center. Maps of Similar data for other U.S. locations can be browsed in an online interactive map feature.

CREDIT

Credit: Suzanne Benz

USAGE RESTRICTIONS

AGU supports 130,000 enthusiasts to experts worldwide in Earth and space sciences. Through broad and inclusive partnerships, we advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.  

Notes for Journalists:

Earth's Future is open access. Download a PDF copy of the paper here. Neither the paper nor this press release is under embargo.  

Paper title:

"Widespread race and class disparities in surface urban heat extremes across the United States"  

Authors: 

Susanne A. Benz and Jennifer A. Burney, School of Global Policy and Strategy, UC San Diego, 9500 Gilman Drive, La Jolla CA, USA 92037 

US citizen migrant children in Mexico lacking adequate health insurance

Researchers call for transborder policies to address place-based inequity in health coverage

UNIVERSITY OF HOUSTON

Research News

 

IMAGE: SHARON BORJA, ASSISTANT PROFESSOR, UNIVERSITY OF HOUSTON GRADUATE COLLEGE OF SOCIAL WORK view more 

CREDIT: UNIVERSITY OF HOUSTON

While attending a conference at the Universidad Nacional Autónoma de México in Mexico City several years ago, Sharon Borja was struck by the story of a young man who, as a child, joined his parents repatriating to their native country of Mexico. Like millions of Mexican immigrants, the family had called the United States home for years, and having been born in the U.S., he was an American citizen. Walking one day in his newfound urban Mexican neighborhood, a couple carrying a wooden stick approached him on the street and encouraged him to do the same, Borja recalled the man sharing.

"The stick was for protection against all the stray dogs," said Borja, an assistant professor at the University of Houston Graduate College of Social Work. "He grew up in America and was in a new country for the first time and didn't understand the various challenges. His story sparked my interest in investigating other hurdles U.S. citizen migrant children face when accompanying their parents back to Mexico, including lack of adequate health insurance."

More than a million Mexican nationals and their families that returned to Mexico from the United States in 2015 fueled in part by the Great Recession limiting job opportunities and increased deportation. Among them were 550,000 U.S.-born minors.

An analysis of more than 36,000 of those minors, published in the peer reviewed journal Health Affairs, found that nearly 54% were underinsured. The situation was even more stark in urban settings, where 80% of U.S. citizen migrant children had limited, inadequate insurance. Among the children who lived in Mexican states near the U.S. border, 65% suffered the same fate.

For the study, "underinsured" was defined as those who reported having no insurance or received coverage through public health services or private insurance, which offer narrower coverage, limited access to high-quality care, and modest protection from catastrophic health expenses compared to employment-based programs through Mexico's Social Security Institute.

"We believe health care is a human right. It's a travesty that these U.S. citizen children are vulnerable to financial risk and delays in care and treatment. Many don't even think about this subgroup of at-risk kids, yet they are U.S. citizens who moved to another country, likely not by their choice," said Borja, lead author of the research paper. "These circumstances elevate their risk for lifelong disparities in health and productivity compared with their counterparts who stayed in the U.S."

The study also revealed that parents' level of education and living with an employed mother were associated with a higher likelihood of having the superior employment-based coverage. In addition, the likelihood of having such coverage is reduced by 59% for U.S. citizen migrant children in border states compared with those in other areas.

Although Mexico established a form of universal health care in 2020 called Instituto de Salud para el Bienestar (INSABI), or the Institute of Health for Well-being in English, it faces insufficient funding and does not cover all health conditions, according to the researchers. Regardless, access is guaranteed only for those with proof of citizenship or legal residency. Fewer than half of U.S. citizen migrant children in Mexico in 2015 reported having Mexican citizenship, further putting them at risk for delayed medical care, particularly when there is no alternative to prove eligibility.

The findings underscore the need for transborder health policies that address the growing place-based inequity in health coverage, according to the study authors. They recommend the following solutions:

• Reintegration policies, including assistance to revalidate education and training obtained abroad, to help ease the transition of returning migrants and their families to Mexico.
• Expedited dual-citizenship application process to facilitate receipt of health and social protection programs; a U.S.-Mexico bilateral agreement to recognize birth certificates from either country as proof of dual citizenship could further simplify the registration of U.S. citizen migrant children in programs such as INSABI, as these documents already bear their parents' nationalities.
• Exempting U.S. citizen migrant children who reside in the 80 Mexican municipalities within approximately 60 miles of the U.S.-Mexico border from automatic suspensions of Medicaid and Children's Health Insurance Program (CHIP) benefits to ensure uninterrupted care via telemedicine and in-person consultation with U.S. health care providers.
• Creation of a workgroup within the Comisión de Salud Fronteriza México-Estados Unidos (U.S.-Mexico Border Health Commission) to help monitor the health status and needs of U.S. citizen migrant children.

Other authors of the research paper include Jodi Berger Cardoso, University of Houston; Pedro Isnardo De La Cruz, Universidad Nacional Autónoma de México; Krista Perreira, University of North Carolina; Natalia Giraldo-Santiago, University of Houston Ph.D. candidate; Martha Virginia Jasso Oyervides, Universidad Autónoma de Coahuila.

The researchers acknowledge that the evolving geopolitical landscape of U.S.-Mexico migration and the recent implementation of INSABI could present a different picture now, six years after their data was collected. But with increased deportations during the Trump Administration, the numbers of U.S. citizen migrant children lacking adequate health insurance is likely even higher today.

"We recognize that the implementation of cross-border health initiatives could be costly. But the long-term societal savings of investing in early childhood and ensuring timely access to high quality preventive care far outweigh the cost," wrote the researchers. "Sustained political will and consistent commitment to invest in U.S. citizen migrant children, who are often an ignored segment of the population, are needed so that they do not become 'out of sight and out of mind.'"

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#AUSTERITYKILLS

Cuts to local government funding in recent years cost lives, study finds

#CRIMEAGAINSTHUMANITY

UNIVERSITY OF LIVERPOOL

Research News

 

A new study from researchers at the University of Liverpool shows that decreasing local government funding over recent years probably contributed to declines in life expectancy in some areas of England, which was stalling even prior to the COVID-19 pandemic.

Local government funding and life expectancy in England, a longitudinal ecological study published in The Lancet Public Health, linked annual local government funding data from the Ministry of Housing, Communities, and Local Government with life expectancy and mortality data from Public Health England between 2013 and 2017.

Corresponding author Dr Alexandros Alexiou said: "Since 2010, large reductions in funding for local government services have been introduced in England, which led to reduced provision of health-promoting public services. We wanted to investigate whether areas that showed a greater decline in funding also had more adverse trends in life expectancy and premature mortality.

"Prior to the COVID-19 pandemic, stalling life expectancy in England was a major public health concern, and the causes were unclear.

"Our research shows that cuts to local government over recent years have probably cost lives. We found that, during a period of large reductions in funding for local government in England, areas that experienced the greatest cuts also experienced slower improvements or a decline in life expectancy. As funding for the most deprived areas decreased to a greater extent, they experienced the most adverse impact - widening health inequalities.

"This has important implications for current policy and for recovery from the COVID-19 pandemic."

On average between 2013 and 2017 central funding to local governments decreased by 33% or £168 per person in total. Each £100 reduction in funding per person was associated with an decrease in 1.3 months in male life expectancy and 1.2 months in female life expectancy.

As funding reductions were greater in more deprived areas, these places were more severely affected, increasing the gap in life expectancy between those places and more affluent areas. Researchers estimated that cuts in funding increased the gap in life expectancy between the most and least deprived areas by 3% for men and 4% for women. Overall reductions in funding during this period were associated with an additional 9600 deaths in people younger than 75 years old.

Dr Alexiou added: "Our study suggests that reduced funding for local services that disproportionally affected deprived areas have had a significant impact on health. The UK government has declared that austerity is over and has committed to investing more to 'level up' those places that have previously been 'left behind'. Fair and equitable investment in local government services can redress these inequalities, enabling the country to 'build back better'."

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This work was funded by the NIHR and MRC.

The full paper is available in the Lancet Public Health, here: http://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00110-9/fulltext