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)
Tuesday, July 21, 2020
Racial discrimination may adversely impact cognition in African Americans
BOSTON UNIVERSITY SCHOOL OF MEDICINE
(Boston)--Experiences of racism are associated with lower subjective cognitive function (SCF) among African-American women.
Rates of incident dementia and Alzheimer's Disease (AD) are higher in African Americans than in white Americans. In many studies, older African Americans perform more poorly on neuropsychological cognition tests compared to white Americans. Experiences of racism are common among African Americans, with 50 percent or more respondents to a 2017 national survey reporting such experiences. These institutional and daily forms of racism have been associated with increased risks of various conditions that can impair cognition, including depression, poor sleep, type 2 diabetes and hypertension.
Using data from the Black Women's Health Study (a prospective cohort study established in 1995, when 59,000 black women aged 21 through 69 years enrolled by completing health questionnaires) researchers from Boston University's Slone Epidemiology Center quantified the association between experiences of racism and SCF, based on six questions about memory and cognition.
They found that experiences of both daily and institutional racism were associated with decreased SCF. Women reporting the highest level of daily racism had 2.75 times the risk of poor SCF as women reporting the lowest level of daily racism. Women in the highest category of institutional racism had 2.66 times the risk of poor SCF as those who reported no such experiences.
"Our findings of a positive association of experiences of racism with poorer subjective cognitive function are consistent with previous work demonstrating that higher perceived psychological stress is associated with greater subjective memory decline," explains senior author Lynn Rosenberg, ScD, epidemiologist at the Slone Epidemiology Center at Boston University and a principal investigator of the Black Women's Health Study. "Our work suggests that the chronic stress associated with racial discrimination may contribute to racial disparities in cognition and AD," added Rosenberg, who is also a professor of epidemiology at Boston University School of Public Health.
Future work is needed to examine whether exposure to institutional and daily racism accelerates conversion to Alzheimer's dementia and/or increases levels of AD biomarkers, such as cerebrospinal fluid or PET markers of amyloid ? and tau pathology, according to the researchers.
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These findings appear online in the journal Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring.
This study was supported in part by the National Cancer Institute grants R01CA058420 and UM1CA164974, the National Institute on Aging grant R21AG060269 and Alzheimer's Association grant AARG-17-529566.
POST MODERN ALCHEMY
Lithium ion battery waste used in biodiesel production from discarded vegetable oil
Using mixtures of metal hydroxides as a catalyst provides way to make cleaner fuel in minutes at room temperature
AMERICAN INSTITUTE OF PHYSICS
IMAGE: THE TWO-PHASE SYSTEM CONTAINING BIODIESEL (UPPER PHASE) AND GLYCEROL (LOWER PHASE) view more
CREDIT: GILBERTO MAIA DE BRITO
WASHINGTON, July 21, 2020 -- The production of biodiesel from vegetable oil has been around for more than 150 years, and the approach significantly reduces several pollutants associated with burning fossil fuels. Vegetable oils, however, can be notoriously difficult to use in an engine, providing low power output and release of unique toxic byproducts.
Brazilian researchers demonstrated a new chemical approach for producing biodiesel from domestic cooking oil waste by using hydroxide lithium mixed with either sodium hydroxides or potassium hydroxides as catalysts. Their work, published in the Journal of Renewable and Sustainable Energy, by AIP Publishing, could enable future studies related to the use of lithium from waste lithium ion batteries.
The work marks one of the first times lithium has been used for such purposes. Author Gilberto Maia de Brito said green engineering can yield solutions for a variety of problems at the same time.
"The results achieved in this work will make it possible to expand the use of new types of metallic catalysts to a higher level, such as lithium, applied to the production of biodiesel," he said. "Before, in practice, these were just restricted to sodium hydroxide and potassium hydroxide."
The group's technique draws on one proposed solution for creating biodiesel, called transesterification, which can yield fuel in a matter of minutes at room temperature.
The researchers collected waste cooking oil samples from fast food restaurants and homes, some of the biggest sources of waste disposed of inappropriately, and lithium hydroxide from lithium ion battery waste.
When catalyzed by the mixture of metal hydroxides, the transesterification reaction split the cooking oil into a biodiesel layer and a layer of glycerol, which itself can be used in a variety of ways such as producing food sweeteners, alleviating certain skin conditions and acting as a main reactant in making antifreeze.
With the right proportions of catalysts, the group was able to produce biodiesel with an average yield of 90%. They analyzed the biodiesel, using techniques ranging from infrared spectroscopy to chromatography to nuclear magnetic resonance studies, to assess the purity of their fuel.
"We were surprised that what came out was not only some results, but actually very good results related to the yield production," Maia de Brito said. "The fast phase separation and the main chemistry and physics properties of that biodiesel produced from lithium were also surprising."
Maia de Brito hopes to continue finding new ways to recover lithium from waste and use it to facilitate biofuel production even further.
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The article, "Eco-green biodiesel production from domestic waste cooking oil by transesterification using LiOH into basic catalysts mixtures," is authored by Gilberto Maia Brito, Mariana Borsoi Chicon, Edumar Ramos Coelho, Diêgo Nunes Faria and Jair Checon de Freitas. The article will appear in Journal of Renewable and Sustainable Energy on July 21, 2020 (DOI: 10.1063/5.0005625). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0005625.
ABOUT THE JOURNAL
Journal of Renewable and Sustainable Energy is an interdisciplinary journal that publishes across all areas of renewable and sustainable energy relevant to the physical science and engineering communities. Topics covered include solar, wind, biofuels and more, as well as renewable energy integration, energy meteorology and climatology, and renewable resourcing and forecasting. See https://aip.scitation.org/journal/rse.
How adding green tea extract to prepared foods may reduce the risk for norovirus
In study, edible coating made with tea extract killed the virus and bacteria
OHIO STATE UNIVERSITY
COLUMBUS, Ohio - Infusing prepared foods with an edible coating that contains green tea extract may lower consumers' chances of catching the highly contagious norovirus by eating contaminated food, new research suggests.
Norovirus, which causes vomiting and diarrhea, sickens an estimated 48 million people in the United States every year and causes about 3,000 deaths. It's transmitted from person to person and through consumption of contaminated water and food.
Lots of things we consume contain what are known in the industry as edible films: They can enhance appearance, like wax that makes apples shiny; hold contents together, like plastic drug capsules; and prevent contents from seeping together by, for example, being placed between a prepared pie crust and the filling.
"In many cases, an edible film is in a product, but you are not aware of it," said Melvin Pascall, professor of food science and technology at The Ohio State University and senior study author. "We don't have to put that on the label since the material is edible. That's another way in which we use packaging - and the consumer doesn't have to know."
Some edible films are also enriched with antimicrobial agents that can kill or slow the growth of organisms that cause illness, such as E. coli and mold.
In this new study led by Pascall, adding green tea extract to a film-forming substance created a safe-to-eat barrier that killed norovirus as well as two types of bacteria.
While most antimicrobial packaging advances to date have emphasized fighting bacteria, this finding holds promise for a newer area of research into the concept of using edible film to kill a virus, Pascall said.
"Norovirus is a tough virus to work with - it is a non-enveloped virus, which is the type more resistant to sanitizers and antimicrobial agents," he said. "However, because it has public health concerns and has been implicated in a number of foodborne outbreaks, we wanted to look at the effects of green tea extract on norovirus."
The study is published in the International Journal of Food Science.
Pascall and his team created the films with a base substance called chitosan, a sugar found in the exoskeleton of shellfish. Chitosan is marketed as a weight-loss supplement and used in agricultural and medicinal applications, and has been studied extensively as a safe and readily available compound for edible film development.
Previous studies have suggested that chitosan has antimicrobial properties. But norovirus might exceed its bug-fighting abilities: In this study, the researchers found that chitosan by itself did not kill the virus.
To test the effects of green tea extract, the researchers dissolved it alone in water and added it to a chitosan-based liquid solution and dried film. Several different concentrations of the extract showed effectiveness against norovirus cells, with the highest level tested in this study killing them all in a day.
"We had tested the chitosan by itself and it didn't show much antimicrobial activity against the virus," Pascall said. "But when we added the green tea extract to chitosan, we saw that the film had antiviral properties - so we concluded the antiviral properties were coming from the green tea extract."
The scientists introduced at least 1 million virus cells to the solution and dried films. Those containing green tea extract lowered the presence of virus cells within three hours. The films with the highest concentration of green tea extract reduced norovirus to undetectable levels by 24 hours after the exposure.
Though norovirus was the focus of this work, the researchers also found that green tea extract lowered E. coli K12 and listeria innocua, surrogates for bacteria that also cause foodborne illness, to undetectable levels within 24 hours.
This study didn't identify how the killing happens - typically an antimicrobial agent disables organisms in ways that cause them to die or render them unable to reproduce. The researchers used mouse norovirus cells because human norovirus cells don't grow well in a lab setting.
There is still a lot of work to do before green tea extract-infused films are ready to enter the market. A tricky part of adding natural substances to edible packaging is ensuring that enough is used to deliver the microbe-killing effect without changing the taste or smell of the food.
"A higher concentration of a natural antimicrobial might cause a large drop in the target organism, but at the same time it defeats the purpose of the food by adding an objectionable taste or odor," Pascall said. "There is also the impact of the natural compound on the material itself - it may cause the film to become too brittle or sticky. These are things food scientists have to consider when using antimicrobial agents, especially those from natural sources."
It's also too soon to tell which kinds of food would be the best candidates for antiviral edible films made with green tea extract. It depends on whether the food would be exposed to heat, moisture or acidic conditions, for example. There is also a chance another natural substance could do an even better job - Pascall is conducting similar studies with other extracts.
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Co-authors Collins Amankwaah and Jaesung Lee of the Department of Food Science and Technology and Jianrong Li of the Department of Veterinary Biosciences, all at Ohio State, also worked on the study.
Front-line physicians stressed and anxious at work and home
New study reports moderate to severe stress levels in ER doctors during the frenetic early phase of COVID-19 pandemic
UNIVERSITY OF CALIFORNIA - SAN FRANCISCO
Amid the COVID-19 chaos in many hospitals, emergency medicine physicians in seven cities around the country experienced rising levels of anxiety and emotional exhaustion, regardless of the intensity of the local surge, according to a new analysis led by UC San Francisco.
In the first known study to assess stress levels of U.S. physicians during the coronavirus pandemic, doctors reported moderate to severe levels of anxiety at both work and home, including worry about exposing relatives and friends to the virus. Among the 426 emergency physicians surveyed, most reported changes in behavior toward family and friends, especially decreased signs of affection.
"Occupational exposure has changed the vast majority of physicians' behavior at both work and home," said lead author Robert M. Rodriguez, MD, a professor of Emergency Medicine at UCSF. "At home, doctors are worried about exposing family members or roommates, possibly needing to self-quarantine, and the effects of excess social isolation because of their work on the front line."
The results, which appear July 21, 2020, in Academic Emergency Medicine, found slight differences between men and women, with women reporting higher stress. Among male physicians, the median reported effect of the pandemic on both work and home stress levels was 5 on a scale of 1 to 7 (1=not at all, 4=somewhat, and 7=extremely). For women, the median was 6 in both areas. Both men and women also reported that levels of emotional exhaustion or burnout increased from a pre-pandemic median of 3 to a median of 4 after the pandemic started.
Lack of PPE was associated with the highest level of concern and was also the measure most often cited that would provide greatest relief. The doctors also voiced anxiety about inadequate rapid diagnostic testing, the risk of community spread by discharged patients, and the well-being of coworkers diagnosed with COVID-19.
But the survey also showed clear-cut ways of mitigating anxiety:
Improve access to PPE;
Increase availability of rapid turnaround testing;
Clearly communicate COVID-19 protocol changes;
Assure access to self-testing and personal leave for front line providers.
The responses came from faculty (55 percent), fellows (4.5 percent), and residents (about 39 percent), with a median age of 35. Most physicians lived with a partner (72 percent), while some lived alone (nearly 15 percent) or with roommates (11 percent). Nearly 39 percent had a child under age 18.
The study involved healthcare providers at seven academic emergency departments and affiliated institutions in California, Louisiana and New Jersey. Researchers noted that the majority of study sites were in California, which at the time of the survey had not yet experienced the large surges of patients seen in other areas of the country. But the study found that median levels of anxiety in the California sites were similar to those in the New Orleans and Camden sites, which were experiencing surges at the time.
"This suggests that the impact of COVID-19 on anxiety levels is pervasive and that measures to mitigate stress should be enacted universally," Rodriguez said. "Some of our findings may be intuitive, but this research provides a critical early template for the design and implementation of interventions that will address the mental health needs of emergency physicians in the COVID-19 pandemic era."
The study is longitudinal, with this first phase focused on the early "acceleration" phase of the pandemic. Subsequent studies will address stressors that have arisen throughout the course of the pandemic, including childcare and homeschooling demands, the economic impact of fewer patients overall in the ER, and possible development of long-term post-traumatic stress.
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Authors: From the University of California, co-authors are Anthony Medak, MD, of UC San Diego; Brian Chinnock, MD, of the UCSF-Fresno Medical Education Program; Remi Frazier, MS, of UCSF; and Richelle Cooper, MD, of UCLA.
Financial Support: None.
Disclosures: All the authors report no conflict of interest.
About UCSF: The University of California, San Francisco (UCSF) is exclusively focused on the health sciences and is dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. UCSF Health, which serves as UCSF's primary academic medical center, includes top-ranked specialty hospitals and other clinical programs, and has affiliations throughout the Bay Area. Learn more at https://www.ucsf.edu, or see our Fact Sheet.
Twitter data reveals global communication network
Researchers have studied Twitter 'mention' data from 2013 and discovered geographical patches of highly connected individuals
AMERICAN INSTITUTE OF PHYSICS
IMAGE: TOP PANEL: VISUALIZATION OF THE NETWORK ASSOCIATED WITH TWITTER GLOBAL COMMUNICATION. BOTTOM PANEL: BETWEENNESS CENTRALITY OF THE TWITTER COMMUNICATION NETWORK. view more
CREDIT: NEW ENGLAND COMPLEX SYSTEMS INSTITUTE
WASHINGTON, July 21, 2020 -- Twitter mentions show distinct community structure patterns resulting from communication preferences of individuals affected by physical distance between users and commonalities, such as shared language and history.
While previous investigations have identified patterns using other data, such as mobile phone usage and Facebook friend connections, research from the New England Complex Systems Institute looks at the collective effect of message transfer in the global community. The group's results are reported in an article in the journal Chaos, by AIP Publishing.
The scientists used the mentions mechanism in Twitter data to map the flow of information around the world. A mention in Twitter occurs when a user explicitly includes another @username in their tweet. This is a way to directly communicate with another user but is also a way to retransmit or retweet content.
The investigators examined Twitter data from December 2013 and divided the world into 8,000 cells, each approximately 100 kilometers wide. A network was built on this lattice, where each node is a precise location and a link, or edge, is the number of Twitter users in one location who are mentioned in another location.
Twitter is banned in several countries and is known to be more prevalent in countries with higher gross domestic product, so this affects the data. Their results show large regions, such as the U.S. and Europe, are strongly connected inside each region, but they are also weakly connected to other areas.
"While strong ties keep groups cohesive, weak ties integrate groups at the large scale and are responsible for the spread of information systemwide," said co-author Leila Hedayatifar.
The researchers used a computational technique to determine modularity, a value that quantifies distance between communities on a network compared to a random arrangement. They also investigated a quantity known as betweenness centrality, which measures the number of shortest paths through each node. This measure highlights the locations that serve as connectors between many places.
By optimizing the modularity, the investigators found 16 significant global communities. Three large communities exist in the Americas: an English-speaking region, Central and South American countries, and Brazil in its own group. Multiple communities exist in Europe, Asia and Africa.
The data can also be analyzed on a finer scale, revealing subcommunities. Strong regional associations exist within countries or even cities. Istanbul, for example, has Twitter conversations that are largely restricted to certain zones within the city.
The investigators also looked at the effect of common languages, borders and shared history.
"We found, perhaps surprisingly, that countries who had a common colonizer have a decreased preference of interaction," Hedayatifar said.
She suggests hierarchical interactions with the colonizing country might inhibit interactions between former colonies.
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The article, "Geographical fragmentation of the global network of Twitter communications," is authored by Leila Hedayatifar, Alfredo J. Morales and Yaneer Bar-Yam. The article will appear in Chaos on July 21, 2020 (DOI: 10.1063/1.5143256). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/1.5143256.
ABOUT THE JOURNAL
Popular seafood species in sharp decline around the world
UNIVERSITY OF BRITISH COLUMBIA
IMAGE: OCTOPUS AT A FISH MARKET IN INDONESIA. view more
CREDIT: PHOTO BY DENG PALOMARES, SEA AROUND US.
Fish market favourites such as orange roughy, common octopus and pink conch are among the species of fish and invertebrates in rapid decline around the world, according to new research.
In the first study of its kind, researchers at the University of British Columbia, the GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of Western Australia assessed the biomass--the weight of a given population in the water--of more than 1,300 fish and invertebrate populations. They discovered global declines, some severe, of many popularly consumed species.
Of the populations analyzed, 82 per cent were found to be below levels that can produce maximum sustainable yields, due to being caught at rates exceeding what can be regrown. Of these, 87 populations were found to be in the "very bad" category, with biomass levels at less than 20 per cent of what is needed to maximize sustainable fishery catches. This also means that fishers are catching less and less fish and invertebrates over time, even if they fish longer and harder.
"This is the first-ever global study of long-term trends in the population biomass of exploited marine fish and invertebrates for all coastal areas on the planet," said Maria "Deng" Palomares, lead author of the study and manager of the Sea Around Us initiative in UBC's Institute for the Oceans and Fisheries."When we looked at how the populations of major species have been doing in the past 60 years, we discovered that, at present, most of their biomasses are well below the level that can produce optimal catches."
To reach their findings, the researchers applied computer-intensive stock assessment methods known as CMSY and BSMY to the comprehensive catch data by marine ecosystem reconstructed by the Sea Around Us for the 1950-2014 period.
The greatest declines in stocks were found in the southern temperate and polar Indian Ocean and the southern polar Atlantic Ocean, where populations shrunk by well over 50 per cent since 1950.
While much of the globe showed declining trends in fish and invertebrates, the analysis found a few exceptions. One of these was the Northern Pacific Ocean where population biomass increased by 800 per cent in its polar and subpolar zones, and by about 150 per cent in its temperate zone.
Despite these pockets of improvement, the overall picture remains a cause for concern, according to co-author Daniel Pauly, principal investigator at Sea Around Us.
"Despite the exceptions, our findings support previous suggestions of systematic and widespread overfishing of the coastal and continental shelf waters in much of the world over the last 60-plus years," said Pauly. "Thus, pathways for improvements in effective fisheries management are needed, and such measures should be driven not only by clearly set total allowable annual catch limits, but also by well-enforced and sizeable no-take marine protected areas to allow stocks to rebuild."
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"Fishery biomass trends of exploited fish populations in marine ecoregions, climatic zones and ocean basins" was published in Estuarine, Coastal and Shelf Science.
OSU researchers part of international effort to save critically endangered seabird
CORVALLIS, Ore. - The global population of the critically endangered Chinese crested tern has more than doubled thanks to a historic, decade-long collaboration among Oregon State University researchers and scientists and conservationists in China, Taiwan and Japan.
The project included OSU's Dan Roby and Don Lyons and was led by Chen Shuihua of the Zhejiang Museum of Natural History. When it began, fewer than 50 of the seabirds remained.
"The species is still far from being safe from extinction, but the population is now well over 100 adults and the future is much brighter than 10 years ago," said Roby, professor emeritus in the Department of Fisheries and Wildlife in the College of Agricultural Sciences.
Findings were published in Biological Conservation.
First described in 1863, the Chinese crested tern has been a largely mysterious species and is arguably the world's most threatened seabird.
After 21 specimens were collected in 1937 along the coast of Shandong Province, China, it wasn't until 2000 that any other sightings were confirmed: four adults and four chicks within a large colony of greater crested terns in the Matsu Islands, Taiwan.
The discovery was big news in the ornithology world, which had generally considered the Chinese crested tern to be extinct. In the years since, breeding has been confirmed in five locations: three along the Chinese coast, plus an uninhabited island off the southwestern coast of South Korea and the Penghu Islands of Taiwan.
The Chinese crested tern is among the nearly one-third of seabird species threatened with extinction because of entanglement with fishing gear, reduction in food supplies, environmental contaminants, overharvest, and predation and other disturbances by invasive species.
"Most seabirds select nesting habitat largely by social cues, whose absence may delay recovery even when there is suitable habitat," Roby said. "Since the 1970s, new techniques have been developed and implemented to enhance seabird restoration efforts. These techniques are social attraction and chick translocation and have been used in at least 171 different seabird restoration projects conducted in 16 locations in an attempt to restore 64 seabird species."
Social attraction was the strategy for the Chinese crested tern project, the first major conservation effort for seabirds in the People's Republic of China.
"Terns feed their young and provide other parental care for extended periods post-fledging, suggesting that chick translocations would likely not result in fledged young that would survive to recruit into the breeding population," Roby said.
Social attraction involves decoys, recorded bird vocalizations, mirrors, scent and artificial burrows that work in concert to lure adult seabirds to restoration sites with the goal of establishing breeding colonies.
"The most serious immediate threat to the survival of the species was the illegal harvest of eggs by fishermen," Roby said. "Beyond just taking the eggs, the disturbance associated with fishermen landing on breeding islands to collect eggs or shellfish apparently caused breeding terns to abandon their nesting sites."
The scientists believed that if Chinese crested terns could be attracted to a site with suitable nesting habitat that was continuously monitored and secured against egg harvest and other human disturbances, the species could have a chance to recover from the brink of extinction.
In 2013, a tern restoration project was launched on Tiedun Dao, an uninhabited, densely vegetated, 2.58-hectare island in the Jiushan Islands, home to a former breeding colony of Chinese crested terns that was abandoned in 2007 in the wake of illegal egg harvesting.
"It's near the original breeding island of Jiangjunmao but was not known to have been previously occupied by breeding seabirds," Roby said. "To improve the chances for Chinese crested tern success, we used social attraction techniques to try to establish a new breeding colony of greater crested terns because since their rediscovery, Chinese crested terns had only been found nesting in large colonies of greater crested terns."
In 2015, Yaqueshan, a 1-hectare island in the Wuzhishan Archipelago, was chosen as a second restoration site, where social attraction would be deployed in an attempt to stabilize the breeding colony there.
Three years later, the researchers attracted a total of 77 breeding adult Chinese crested terns to the Tiedun Dao and Yaqueshan colonies - 88.5% of the known number of breeding adults in the global population for that year.
Also in 2018, 25 Chinese crested tern chicks fledged from the Tiedun Dao and Yaqueshan colonies, or 96% of the known number of Chinese crested tern fledglings produced that year.
"Consequently, we now know for the first time in history that the global population of Chinese crested terns exceeds 100," Roby said. "The population increase from under 50 to more than 100 is a cautiously hopeful sign that this species can be brought back from the very edge of extinction. The success of this international project is a testimony to what can be accomplished when scientists from China, the U.S. and Taiwan work together toward a common conservation goal."
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Supporting the project were the National Natural Science Foundation of China, the Zhejiang Technological Research Project for Public Welfare, the National Key R&D Program of China, the Biodiversity Investigation, Observation and Assessment Program of the Ministry of Ecology and Environment of China, the Zhejiang Rare and Endangered Wildlife Rescue and Conservation Project, the Endangered Species Monitoring Fund from the State Forestry Administration of China, the Ocean Park Conservation Foundation, the China Association for Science and Technology, the Japan Fund for Global Environment, the U.S. Fish and Wildlife Service and the Pacific Seabird Group.
Spinal stimulators repurposed to restore touch in lost limb
UNIVERSITY OF PITTSBURGH
PITTSBURGH, July 21, 2020 - Imagine tying your shoes or taking a sip of coffee or cracking an egg but without any feeling in your hand. That's life for users of even the most advanced prosthetic arms.
Although it's possible to simulate touch by stimulating the remaining nerves in the stump after an amputation, such a surgery is highly complex and individualized. But according to a new study from the University of Pittsburgh's Rehab Neural Engineering Labs, spinal cord stimulators commonly used to relieve chronic pain could provide a straightforward and universal method for adding sensory feedback to a prosthetic arm.
For this study, published today in eLife, four amputees received spinal stimulators, which, when turned on, create the illusion of sensations in the missing arm.
"What's unique about this work is that we're using devices that are already implanted in 50,000 people a year for pain -- physicians in every major medical center across the country know how to do these surgical procedures -- and we get similar results to highly specialized devices and procedures," said study senior author Lee Fisher, Ph.D., assistant professor of physical medicine and rehabilitation, University of Pittsburgh School of Medicine.
The strings of implanted spinal electrodes, which Fisher describes as about the size and shape of "fat spaghetti noodles," run along the spinal cord, where they sit slightly to one side, atop the same nerve roots that would normally transmit sensations from the arm. Since it's a spinal cord implant, even a person with a shoulder-level amputation can use this device.
Fisher's team sent electrical pulses through different spots in the implanted electrodes, one at a time, while participants used a tablet to report what they were feeling and where.
All the participants experienced sensations somewhere on their missing arm or hand, and they indicated the extent of the area affected by drawing on a blank human form. Three participants reported feelings localized to a single finger or part of the palm.
"I was pretty surprised at how small the area of these sensations were that people were reporting," Fisher said. "That's important because we want to generate sensations only where the prosthetic limb is making contact with objects."
When asked to describe not just where but how the stimulation felt, all four participants reported feeling natural sensations, such as touch and pressure, though these feelings often were mixed with decidedly artificial sensations, such as tingling, buzzing or prickling.
Although some degree of electrode migration is inevitable in the first few days after the leads are implanted, Fisher's team found that the electrodes, and the sensations they generated, mostly stayed put across the month-long duration of the experiment. That's important for the ultimate goal of creating a prosthetic arm that provides sensory feedback to the user.
"Stability of these devices is really critical," Fisher said. "If the electrodes are moving around, that's going to change what a person feels when we stimulate."
The next big challenges are to design spinal stimulators that can be fully implanted rather than connecting to a stimulator outside the body and to demonstrate that the sensory feedback can help to improve the control of a prosthetic hand during functional tasks like tying shoes or holding an egg without accidentally crushing it. Shrinking the size of the contacts -- the parts of the electrode where current comes out -- is another priority. That might allow users to experience even more localized sensations.
"Our goal here wasn't to develop the final device that someone would use permanently," Fisher said. "Mostly we wanted to demonstrate the possibility that something like this could work."
VIDEO: SEVERAL YEARS AGO, BAYNE LOST HER ARM AT THE SHOULDER, BUT SPINAL STIMULATORS ALLOWED HER TO FEEL SENSATIONS IN HER MISSING LIMB CREDIT: UPMC
Everything you ever wanted to know about leech sex but were afraid to ask
SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
IMAGE: GREEN HORSE LEECHES (HAEMOPIS MARMORATA) WERE USED FOR THE GONAD DISSECTIONS. view more
CREDIT: KAREN KIDD
Today, we pull the veil back on the secret sex lives of leeches and how researchers at McMaster University and Fisheries and Oceans Canada are using that information to learn about endocrine disrupting chemicals. Leeches, who gained worldwide popularity when making their film debut in the blockbuster "Stand by Me" in 1986, have actually been around much, much longer. They are found on every continent in freshwater habitats where there is little flow. They are popular bait for fishing, and doctors continue to use them in medical treatments.
We know a lot about leech reproduction. For example, leeches are hermaphroditic, which means they have both male and female sex organs, but that is not all that uncommon for invertebrates. Some families of leeches demonstrate protrandry (they start life as a male and then change into a female), while others self-fertilize, brood eggs and show parental care. Still others cross-fertilize with other leeches, sometimes implanting sperm in one or both of the partners' body walls and sometimes directly introducing sperm into a genital pore with a penis. Their reproductive cycle also varies across families, with some only reproducing one time in their life, and others reproducing multiple times in their lifespan.
We also know a little about the impact of environmental contaminants on leeches. As a matter of fact, leeches have been shown to be highly sensitive to metals in aquatic systems. Leeches can be useful as an environmental quality indicator, as the aquatic ecosystems where leeches are found are often a sink for contaminants. However, even though studies have looked at how some environmental contaminants affect leech populations, very little is known about how they influence leech community composition, species abundance, egg production, growth rates and gonad size. For example, plenty of studies have been conducted at the Experimental Lakes Area in Ontario, Canada, to study the effects of synthetic estrogen (17α-estradiol [EE2]) on fish, other types of invertebrates, and amphibians. Synthetic estrogens are used in oral contraceptives and enter aquatic system when they are not completely broken down in wastewater treatment plants. The compound EE2 was shown to have profound effects on fathead minnows, collapsing their population, and occasionally affected amphibian hatching success and gonad development. However, little attention was given to the effect of EE2 on leech communities until now.
In their article, published in Environmental Toxicology and Chemistry, Karen Kidd, professor at McMaster University and lead author, documents that the EE2 appeared to have little impact on the abundance of leeches, but notes that there was "increased condition in one species and some changes in relative gonad sizes of reproductive organs." This may be because there was an increase in their food supply of other invertebrates, an indirect effect of EE2 linked to reduced fish numbers. For the leech species H. marmorata, the weight of the epididymis (a duct behind the testes) and the sperm sac size decreased, but the length of the testes, prostrate and penis sheath increased in exposed individuals. Likewise, EE2-exposed leeches were associated with growth in ovisac and albumen and vaginal bulb lengths. However, these leeches showed few individual-level and no population- or community-level responses, suggesting that they are much less sensitive to this endocrine disruptor than fish. There had been some thought that leeches may be an ideal study species for assessing contaminant effects - as noted above, they are sensitive to metals and ubiquitous - but, this study suggests that they may be less responsive to endocrine disrupting compounds, such as EE2.
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Women's burden increases in COVID-19 era
FLINDERS UNIVERSITY
Ros Wong, from Flinders University's Climate and Sustainability Policy Research (CASPR) group, was part of a team conducting research across four countries to understand the extent to which COVID-19 restrictions affect women and men differently.
"Women have had to endure additional burdens associated with both paid and unpaid work, often without consideration or the alleviation of other life responsibilities," says Ms Wong, who has completed her PhD at Flinders University this year.
"Women were also tasked with the ongoing organisation of their homes and families under pandemic conditions."
Ms Wong conducted interviews with women from Sri Lanka, Malaysia, Vietnam and Australia that highlight intersections between COVID-19 and gendered burdens, particularly in frontline work, unpaid care work and community activities.
"Our analysis during the early months of the pandemic indicates that women's burdens are escalating. We estimate that women will endure a worsening of their burdens until the pandemic is well under control, and for a long time after."
Ms Wong is critical that public policy and health efforts have not sufficiently acknowledged issues concerned with the associations between gender and disease outbreaks.
She says the study's results will be fundamental to understanding the broader impact both during the crisis and during societal recovery.
"It is critical that public policy and health efforts are proactive in devising transformative approaches that address women's subordinate position in the context of this disease," she says. "In our analysis, we consistently identified that women's burdens across all spheres were not only heavier, but also more dangerous."
Under COVID 19 restrictions in Sri Lanka, women working in frontline health care roles say they faced discrimination in supermarkets when buying groceries, were threatened with eviction, and refused access on public transport.
In Malaysia, only the male head of the household was allowed to shop. Combined with only one person being allowed in a car, this meant that many women were confined to the house unless employed as a frontline worker. However, after a few weeks, this restriction was relaxed, mainly because men struggled to shop effectively and buy basic necessities required for a family.
News media in Vietnam portrayed COVID-19 restrictions as providing the perfect opportunity for women to relax, enjoy a chance for renewed intimacy and to spoil their men - this despite women having to wait in long queues to purchase food and their increased caring duties.
In Australia, childcare and schools did remain open to aid the many health and essential workers with childcare to continue working. However, this placed an extra burden on women as they negotiated school runs, extra housework and caring duties while still employed in essential work.
"COVID-19 restrictions for many women demonstrated once again that women continue to be disadvantaged during natural disasters, war and global pandemics," says Ms Wong.
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The paper - COVID-19 and Women's Triple Burden: Vignettes from Sri Lanka, Malaysia, Vietnam and Australia, by Helen Jaqueline McLaren, Karen Rosalind Wong, Kieu Nga Nguyen and Komalee Nadeeka Damayanthi Mahamadachchi - has been published in Social Sciences journal (doi.org/10.3390/socsci9050087)
