Category: Science

Try moderation, not panic, in response to recent news about aspartame, an expert advises.

The World Health Organization has added aspartame, the chemical that gives products like Diet Coke their distinctly sweet flavor, to its list of potential carcinogens.

The decision came from the WHO’s International Agency for Research on Cancer (IARC), which declared that there is some limited evidence linking aspartame with cancer development in humans. That puts the popular sweetener in the same category as aloe vera extract and certain types of pickled vegetables.

Still, even if the link between aspartame intake and cancer is a tenuous one, Meghan Windham, a registered dietician with Texas A&M University Health Services, says there are plenty of other reasons to consider cutting back on aspartame and other artificial sweeteners.

“If someone likes to have a diet soda occasionally, that’s not a big deal,” Windham says. “But if we’re drinking 12 of them a day, that’s probably not the best choice, regardless of whether it’s carcinogenic or not.”

Here, she explains what’s behind the ruling, and stresses that, as with all things, moderation is key.

What does the aspartame classification mean?

IARC sorts carcinogens and potential carcinogens into several different categories:

• Group 1: Carcinogenic to humans
• Group 2A: Probably carcinogenic to humans
• Group 2B: Possibly carcinogenic to humans
• Group 3: Not classifiable as to its carcinogenicity in humans

The agency has placed aspartame in the less risky “possibly carcinogenic” category, meaning evidence for its cancer-causing properties remains limited. Still, Windham says, that doesn’t mean IARC’s declaration should be entirely discounted.

“Certainly there’s a need to be concerned if something like this is coming out,” she says. “I work with a lot of students, and that’s a question I get a lot: ‘Should I be having these artificially sweetened products?’ So I think there’s always been some level of concern, and this is just bringing it into the spotlight.”

But do I have to give up diet soda?

Following IARC’s announcement, the Joint Expert Committee on Food Additives—a group composed of scientists from the WHO and the Food and Agriculture Organization of the United Nations—announced guidelines for how much aspartame a person can consume safely.

According to their figures, one’s daily intake of the artificial sweetener should not exceed 40 milligrams per kilogram of body weight. That means a person weighing 150 pounds could consume around a dozen diet sodas a day and still be considered safe, at least as far as cancer risk is concerned.

Windham’s advice? Don’t even get near that number.

“Too much of anything is not a good thing,” she says. “Just because 12 diet drinks a day is ‘safe,’ that’s not the best choice nutritionally. When we think about sugared beverages in general, whether they’re sweetened with stevia, truvia, sucralose, aspartame, or even actual sugar, nutritionally there’s not much there. There’s usually no protein, no healthy fats, they’re not fiber rich. So if we’re just drinking those all day to sustain us, that’s probably not the best.”

Still, she says, that doesn’t mean anyone should have to go cold turkey on artificially sweetened beverages. Just like with processed meats containing nitrates and nitrites—which the WHO classifies in the higher category of “probably carcinogenic”—there’s typically nothing wrong with consuming these products occasionally.

“I always say everything in moderation,” Windham says. “Ideally, we should focus on good old water, low fat milk, and other hydration sources that don’t have sugar or any type of artificial sweetener in them.

“But when we have populations, maybe a type 2 diabetic or someone with a medical condition where they need to choose lower levels of actual sugar, some of these diet drinks are beneficial for them. So I encourage it in those populations who maybe want to take a step down from regular sugared beverages.”

Source: Luke Henkhaus for Texas A&M University

Marine protected areas offer many social and ecological benefits, but they’re not resilient to the effects of ocean warming, research finds.

Marine protected areas (MPAs) are locations in the ocean where human activities such as fishing are restricted to conserve and protect marine ecosystems, habitats, species, and cultural resources. The study, part of a 10-year review of California’s MPA network conducted at the University of California, Santa Barbara’s National Center for Ecological Analysis & Synthesis (NCEAS), finds that marine heatwaves affect ecological communities regardless of whether they are protected inside MPAs.

“MPAs in California and around the world have many benefits, such as increased fish abundance, biomass, and diversity,” says Joshua Smith, who led the study while a postdoctoral researcher at NCEAS. “But they were never designed to buffer the impacts of climate change or marine heatwaves.”

The findings appear in Global Change Biology.

‘The Blob’ and El Niño

Smith and coauthors from all over the world were part of an NCEAS working group formed to synthesize decades of long-term ecological monitoring data from California’s diverse ocean habitats. The group, co-led by Jenn Caselle, a researcher with UC Santa Barbara’s Marine Science Institute, and Kerry Nickols, a professor from Cal State University Northridge who now works with the nonprofit Ocean Visions, aimed to provide actionable scientific results to California’s policy makers and natural resource managers, as part of a statewide Decadal Evaluation of the MPA network.

Their analyses spanned the largest marine heatwave on record, which rolled through the Pacific Ocean toward California from 2014-2016.

The monster marine heatwave was formed from an environmental double-whammy—unusual ocean warming nicknamed “The Blob,” followed by a major El Niño event that prolonged the sweltering sea temperatures. The marine heatwave blanketed the West Coast from Alaska to Baja and left a wake of altered food webs, collapsed fisheries, and shifted populations of marine life, among various other consequences.

As MPA managers around the world face increasing climate shocks, the extent to which MPAs can buffer the worst of these events has become an important question. The working group scientists asked how the ecological communities in California’s protected areas fared after such a severe and prolonged heatwave: Would the communities shift and if so, how? Would they “bounce back” when the marine heatwave subsided? Could the marine protected areas protect sensitive populations or facilitate recovery?

MPAs and climate resilience

To find answers to their questions, they synthesized over a decade of data collected from 13 no-take MPAs located in a variety of ecosystems along the Central Coast: rocky intertidal zones, kelp forests, shallow and deep rocky reefs. The team looked at fish, invertebrates, and seaweed populations inside and outside these areas, using data from before, during, and after the heatwave.

They also focused on two of these habitats, rocky intertidal and kelp forests, at 28 MPAs across the full statewide network to gauge whether these locations promoted one particular form of climate resilience—maintaining both population and community structure.

“We used no-take MPAs as a type of comparison to see whether the protected ecological communities fared better to the marine heatwave than places where fishing occurred,” says Smith, now an Ocean Conservation Research Fellow at Monterey Bay Aquarium.

The results are somewhat sobering, though not altogether unexpected.

“The MPAs did not facilitate resistance or recovery across habitats or across communities,” Caselle says. “In the face of this unprecedented marine heatwave, communities did change dramatically in most habitats. But, with one exception, the changes occurred similarly both inside and outside the MPAs. The novelty of this study was that we saw similar results across many different habitats and taxonomic groups, from deep water to shallow reefs and from fishes to algae.”

The implication of these findings, according to Smith, is that every part of the ocean is under threat from climate change. “MPAs are effective in many of the ways they were designed, but our findings suggest that MPAs alone are not sufficient to buffer the effects of climate change.”

Warm-water species moving in

The key question now is what will happen in the future? At the time of this study using data through 2020, the ecological communities have not returned to their former, pre-heatwave state. According to the paper, these ecological communities shifted toward a “pronounced decline in the relative proportion of cold-water species and an increase in warm water species.” For example, increases in the abundance of the señorita fish (Oxyjulis californica), a subtropical species with warm water affinity and previously rare in central California, had an outsized influence on the shift of communities. Whether these species persist in their new locations remains to be seen.

“This study makes it clear why long-term monitoring of California’s MPAs is so critical,” says Caselle. “Some of these time series are longer than 25 years at this point and the data are critical to understanding and readying human communities for the changes occurring in our marine communities.” Continued study will show if future shifts in marine communities occur at different rates or to different base states in MPAs compared to fished areas.

Despite the limited ability of MPAs to resist the grip of the marine heatwave, they do confer benefits, not the least of which is the ability to study the complex effects of climate change in areas not affected by fishing. As areas of minimal human interference that are regularly monitored, they present opportunities to study the response of marine ecosystems to shifting conditions and potentially tailor management techniques accordingly. Moreover, as Smith stated, “the ecological communities in MPAs are still being protected, even if they are different as a result of the heatwave. Given that marine heatwaves are anticipated to increase in frequency and magnitude into the future, swift climate action and nature-based solutions are needed as additional pathways to enhance the health of our oceans.”

Nickols adds, “With the devastating impacts of climate change already apparent, it is very important that we are upfront about climate solutions—as long as we are burning fossil fuels and warming the globe marine ecosystems will be at risk, even if they are protected from fishing.”

This paper is the first in a series led by the NCEAS working group. Forthcoming articles examine human engagement across the California MPA network, the effect of MPAs on fish populations and fisheries, and a synthesis of marine protected areas that work for people and nature.

Source: UC Santa Barbara

With paid leave, older adults are spending less time looking after their grandchildren and more time looking after their parents.

In 2004, California passed a law requiring employers above a certain size to provide paid family leave to their employees.

Much of the research looking at this policy has examined its effect on the work, income and leave-taking of new parents and women of childbearing age—but less research has focused on how paid leave may affect older adults.

“The law could affect older adults directly, by enabling them to take paid leave to take care of sick relatives when they wouldn’t have before. But it could also affect older adults indirectly, if it enables new parents to take paid leave,” says University of Michigan economist Joelle Abramowitz.

“If grandparents provided significant amounts of care to their grandchildren because the parents of those grandchildren did not have access to paid leave, now that the parents of those grandchildren are able to take paid leave, we would expect to see grandparents spend less time caregiving to their grandchildren.”

The research team drew from the 1998-2016 waves of University of Michigan’s Health and Retirement Study (HRS), a longitudinal study of approximately 20,000 Americans over age 50 and their spouses. The study is nationally representative, and participants are interviewed every two years.

The HRS asks respondents with grandchildren if they or their spouses spent 100 or more hours in total taking care of their grandchildren in the past two years. If respondents answer yes, they are asked how many hours they spent taking care of grandchildren in the past two years and how many hours their spouse spent taking care of grandchildren in the past two years.

Likewise, the HRS asks respondents with parents if they or their spouses spent 100 or more hours in total helping their parents with basic personal activities in the past two years. If respondents answer yes, they are asked how many hours each they and their spouse spent helping their own parents and their spouse’s parents in the past two years. The researchers combined values for helping the respondent’s own parents and their spouse’s parents.

Additionally, the researchers were able to compare outcomes for residents of California to residents of other states using a restricted-use version of the data with state identifiers.

After the implementation of the paid-leave law, the researchers found that the respondents spent, on average, 96 hours helping parents with basic needs and 190 hours caring for grandchildren over the past two years. Compared to before the paid leave law was implemented, this represents a 17% decrease in grandparents’ time spent caring for grandchildren in the past two years and a 40-50% increase in time spent helping parents with personal activities. In terms of hours, older adults are spending 39 fewer hours caring for grandchildren and 41 more hours caring for their parents.

The effects for women are larger, Abramowitz says. Women spend 48 hours fewer caring for their grandchildren and 53 more hours caring for their parents. Men spend 24 hours less caring for grandchildren and 30 hours more caring for their parents.

These hours don’t reflect the total amount of time that people spend with their grandchildren or parents, Abramowitz says. The hours only include time spent caregiving to relatives.

“One distinction I want to make is that the question on the survey specifically asks about caring for grandchildren, not about spending time with your grandchildren. For parents, we look at spending time helping them with basic needs—just chores and functional tasks,” Abramowitz says. “We really focus on the caregiving aspect as opposed to how much time respondents are spending with their family members.”

Abramowitz says it’s important to look beyond the immediate effects of this policy on the caregiving choices of new parents. The policy may have indirect effects on older adults’ ability to work longer rather than retiring in order to give care to their parents.

“There has been a lot of focus on new parents and not as much focus on older adults, but they’re also people who engage in a lot of caregiving,” she says. “This law potentially supports older caregivers, which enables more options for providing care to their parents.

“I think it’s important to have more evidence about how policy can influence people’s choices in terms of institutional care versus home care. Additionally, these policies can influence people’s ability to work longer. If people want to work longer, how do we facilitate that ability?”

The findings appear in the Journal of Aging and Social Policy.

Source: University of Michigan

A green tea compound with powerful antioxidant properties could be promising for both treating and preventing uterine fibroids, according to a new pre-clinical, proof-of-concept study.

The findings in the journal Scientific Reports add to growing evidence that the compound, epigallocatechin gallate (EGCG), may reduce fibroid cell growth. The study was specifically designed to identify the biochemical mechanisms responsible for EGCG action in fibroid cells.

The investigators emphasize that their study involves human fibroid cells grown in the laboratory and treated with EGCG extract to explore the possibility of oral EGCG supplementation as a therapy, rather than just drinking cups of green tea as a preventative measure for uterine fibroids.

“The purpose of this study was to examine how EGCG works to treat and prevent uterine fibroids,” says James Segars Jr., professor of gynecology and obstetrics at the Johns Hopkins University School of Medicine. “There is no standard protocol for uterine fibroid disease management or prevention, no tools to prevent their growth, so finding a safe nonsurgical therapy is important.”

Uterine fibroids are the most common benign tumors of the uterus. Made up of smooth muscle cells and a large matrix of connective tissue, the fibroids range in size from nearly microscopic to bulky masses that can enlarge and distort the uterus.

An estimated 77% of women will develop fibroids in their lifetime, most of them by age 50. Black and Hispanic women develop them at 1.5 to two times the rate of white women.

While many people with uterine fibroids are without symptoms, about 25% experience significant symptoms including heavy uterine bleeding, pelvic pain, and infertility. Uterine fibroids are the leading cause of hospitalization for hysterectomy in the United States, according to the US Department of Health and Human Services. In addition to complete removal of the uterus, surgical treatment may include various means of removing fibroid tumors from the uterine wall.

For the new study, researchers used laboratory cultures of uterine fibroids collected from living patients. Because uterine fibroid cells have a large extracellular matrix (the network of macromolecules and minerals in tissues that support, but are not part of, cells) compared to normal cells, researchers designed their experiments to see if treatment of cells with EGCG affects protein expression associated with this matrix.

Specifically, they studied fibronectin, a matrix protein; cyclin D1, a protein involved with cell division; and connective tissue growth factor (CTGF) protein.

Cells were dosed with 100 micromoles (a micromole is 1 millionth of a mole) per liter of EGCG in growth media for 24 hours, and then a Western blot—a laboratory technique used to detect a specific protein in a blood or tissue sample—was performed. In this study, researchers looked for levels of cyclin D1 and CTGF proteins in EGCG-treated fibroid cells compared to untreated cell.

They found that EGCG reduced protein levels of fibronectin by 46% to 52%, compared with an untreated control group of fibroid cells. They also found that EGCG disrupted pathways involved in fibroid tumor cell growth, movement, signaling and metabolism, and they saw up to an 86% decrease in CTGF proteins compared with the control group.

“The results from this study show that EGCG targets many signaling pathways involved in fibroid growth, particularly the extracellular matrix,” says lead author Md Soriful Islam, a postdoctoral fellow at the Johns Hopkins University School of Medicine. “EGCG supplements could be an easily accessible and natural way to relieve symptoms and slow fibroid growth.”

These results lend support to the FRIEND (Fibroids and Unexplained Infertility Treatment With Epigallocatechin Gallate; A Natural Compound in Green Tea) study, an ongoing clinical trial of EGCG in women with fibroids who are seeking pregnancy.

While results from this study show promise, researchers caution that more studies need to be done, and consumers should not try to self-dose with green tea supplements. Future research on EGCG will include clinical trials with large and diverse patient groups to determine optimal doses as well as possible side effects of EGCG supplementation.

Segars has been a primary investigator on research sponsored by Bayer, Abbvie, BioSpecifics Technologies Corp., Allergan, and Myovant Sciences. All other authors have no conflicts to disclose.

The National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the Howard W. and Georgeanna Seegar Jones Endowment partly supported the work.

Source: Johns Hopkins University

Children with autism have memory challenges that hinder not only their memory for faces but also their ability to remember other kinds of information, according to new research.

These other impairments are reflected in distinct wiring patterns in the children’s brains, the researchers report.

The findings clarify a debate about memory function in kids with autism, showing that their memory struggles surpass their ability to form social memories and should prompt broader thinking about autism in children and about treatment of the developmental disorder, according to the scientists who conducted the study.

“Many high-functioning kids with autism go to mainstream schools and receive the same instruction as other kids,” says lead author Jin Liu, a postdoctoral scholar in psychiatry and behavioral sciences at Stanford University. Memory is a key predictor of academic success, says Liu, adding that memory challenges may put kids with autism at a disadvantage in school.

The study’s findings also raise a philosophical debate about the neural origins of autism, the researchers say. Social challenges are recognized as a core feature of autism, but it’s possible that memory impairments might significantly contribute to the ability to engage socially.

“Social cognition can not occur without reliable memory,” says senior author Vinod Menon, a professor of psychiatry and behavioral sciences.

“Social behaviors are complex, and they involve multiple brain processes, including associating faces and voices to particular contexts, which require robust episodic memory. Impairments in forming these associative memory traces could form one of the foundational elements in autism.”

Autism and memory

Autism, which affects about one in every 36 kids, is characterized by social impairments and restricted, repetitive behaviors. The condition exists on a wide spectrum. The most severely affected individuals cannot speak or care for themselves, and about one-third of people with autism have intellectual impairments.

On the other end of the spectrum, many people with high-functioning autism have normal or high IQ, complete higher education, and work in a variety of fields.

Research has shown that children with autism have difficulty remembering faces. Some research has also suggested that children with autism have broader memory difficulties, but these studies were small and did not thoroughly assess participants’ memory abilities. They included children with wide ranges of age and IQ, both of which influence memory.

To clarify the impact of autism on memory, the new study included 25 children with high-functioning autism and normal IQ who were 8 to 12 years old, and a control group of 29 typically developing children with similar ages and IQs.

All participants completed a comprehensive evaluation of their memory skills, including their ability to remember faces; written material; and non-social photographs, or photos without any people.

The scientists tested participants’ ability to accurately recognize information (identifying whether they had seen an image or heard a word before) and recall it (describing or reproducing details of information they had seen or heard before). The researchers tested participants’ memory after delays of varying lengths. All participants also received functional magnetic resonance imaging scans of their brains to evaluate how regions known to be involved in memory are connected to each other.

Beyond faces

In line with prior research, children with autism had more difficulty remembering faces than typically developing children, the researchers found.

The research showed they also struggled to recall non-social information. On tests about sentences they read and non-social photos they viewed, their scores for immediate and delayed verbal recall, immediate visual recall, and delayed verbal recognition were lower.

“We thought that behavioral differences might be weak because the study participants with autism had fairly high IQ, comparable to typically developing participants, but we still observed very obvious general memory impairments in this group,” Liu says.

Among typically developing children, memory skills were consistent: If a child had good memory for faces, he or she was also good at remembering non-social information.

This wasn’t the case in autism. “Among children with autism, some kids seem to have both impairments and some have more severe impairment in one area of memory or the other,” Liu says.

The researchers had not expected this.

“It was a surprising finding that these two dimensions of memory are both dysfunctional, in ways that seem to be unrelated—and that maps onto our analysis of the brain circuitry,” Menon says.

The brain scans showed that, among the children with autism, distinct brain networks drive different types of memory difficulty.

Over-connected brain circuits

For children with autism, the ability to retain non-social memories was predicted by connections in a network centered on the hippocampus—a small structure deep inside the brain that is known to regulate memory.

But face memory in kids with autism was predicted by a separate set of connections centered on the posterior cingulate cortex, a key region of the brain’s default mode network, which has roles in social cognition and distinguishing oneself from other people.

“The findings suggest that general and face-memory challenges have two underlying sources in the brain which contribute to a broader profile of memory impairments in autism,” Menon says.

In both networks, the brains of children with autism showed over-connected circuits relative to typically developing children. Over-connectivity—likely due to too little selective pruning of neural circuits—has been found in other studies of brain networks in children with autism.

New autism therapies should account for the breadth of memory difficulties the research uncovered, as well as how these challenges affect social skills, Menon says. “This is important for functioning in the real world and for academic settings.”

The study appears in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.

The National Institutes of Health and the Stanford Maternal and Child Health Research Institute funded the work.

Source: Stanford University

New research explains the mysterious “Blood Falls” of Antarctica.

During the infamous Terra Nova Expedition to Antarctica in 1911, British geologist Thomas Griffith Taylor made a mysterious discovery at the rocky base of the glacier that now bears his name: a waterfall of what appeared to be blood.

Discharged from beneath the ice at the glacier’s tongue, the water emerges clear but then quickly turns crimson. For more than a century, this phenomenon that Taylor dubbed “Blood Falls” has captured people’s imaginations and remained a scientific mystery—until now.

Using powerful transmission electron microscopes at Johns Hopkins’ Materials Characterization and Processing facility, Ken Livi, a research scientist in the Whiting School’s department of materials science and engineering, examined solids in samples of Blood Falls’ water and found an abundance of tiny, iron-rich nanospheres that oxidize, turning the water seemingly gory. (Nanospheres are tiny round objects—100th the size of the average human red blood cell—with unique physical and chemical characteristics.)

“As soon as I looked at the microscope images, I noticed that there were these little nanospheres and they were iron-rich, and they have lots of different elements in them besides iron—silicon, calcium, aluminum, sodium—and they all varied,” Livi says.

Livi worked on the project as part of a team that included experts at other institutions, including Jill A. Mikucki, a University of Tennessee microbiologist who has been investigating the Taylor Glacier and Blood Falls for years. Their results appear in Frontiers in Astronomy and Space Sciences.

Livi says that the nature of the nanospheres he identified went undetected not only because they are minuscule, but also because previous research teams believed that some sort of mineral was causing the “bloody” water, and the real culprit—nanospheres—aren’t minerals.

“In order to be a mineral, atoms must be arranged in a very specific, crystalline, structure. These nanospheres aren’t crystalline, so the methods previously used to examine the solids did not detect them,” says Livi.

To understand the longstanding Blood Falls mystery, you must first understand Antarctic microbiology, according to Livi.

“There are microorganisms that have been existing for potentially millions of years underneath the saline waters of the Antarctic glacier. These are ancient waters,” he says.

The ancient iron- and salt-rich waters under the glacier are host to strains of bacteria that may not have changed for millennia. Scientists believe that understanding this highly unusual environment and its lifeforms could also inform the search for—and understanding of—life on other planets with similarly inhospitable environments. In fact, that is how Livi, an expert in planetary materials, came to tackle the mystery of Blood Falls.

“With the advent of the Mars Rover missions, there was an interest in trying to analyze the solids that came out of the waters of Blood Falls as if it was a Martian landing site,” he says. “What would happen if a Mars Rover landed in Antarctica? Would it be able to determine what was causing the Blood Falls to be red? It’s a fascinating question and one that several researchers were considering.”

One of those was Mikucki, whose team had previously conducted an analysis of Blood Falls samples using devices and methods identical to those employed by rovers traversing the surface of the Red Planet. A prolific Antarctic researcher, Mikucki was part of the team that first identified the presence of living organisms in the lake beneath the Taylor Glacier. That team mapped the caves and rivers of the glacier to the water’s source: an ancient, briny subglacial reservoir containing myriad minerals gathered by the ice in its crawl across the rocks below. The reason for the water’s startling gory appearance, though, remained unclear.

So Mikucki and astronomer Darby Dyar from Mount Holyoke College sent the samples from Mikucki’s most recent Antarctic expedition to Hopkins’ state-of-the-art MCP facility to be tested by Livi, a specialist in transmission electron microscopy, and he uncovered the nanospheres.

Livi is confident that the team has solved the Blood Falls mystery but says its research has uncovered another issue that now needs to be addressed.

“Our work has revealed that the analysis conducted by rover vehicles is incomplete in determining the true nature of environmental materials on planet surfaces. This is especially true for colder planets like Mars, where the materials formed may be nanosized and non-crystalline. Consequently, our methods for identifying these materials are inadequate. To truly understand the nature of rocky planets’ surfaces, a transmission electron microscope would be necessary, but it is currently not feasible to place one on Mars,” he says.

Source: Jack Darrell for Johns Hopkins University

The prevalence of moderate or severe arthritis joint pain varies strikingly across American states, ranging from 6.9% of the population in Minnesota to 23.1% in West Virginia, according to a new study.

The researchers used a combination of individual- and macro-level measures to reach new insights into geographic differences in pain and their causes.

“The risk of joint pain is over three times higher in some states compared to others, with states in the South, especially the lower Mississippi Valley and southern Appalachia, having particularly high prevalence of joint pain,” says first author Rui Huang, a sociology PhD student at the University at Buffalo.

“We also observed educational disparities in joint pain in all states that vary substantially in magnitude, even after adjusting for demographic characteristics.”

The percentage point difference in arthritis pain prevalence between people who did not complete high school versus those who obtained at least a bachelor’s degree is much larger in West Virginia (31.1), Arkansas (29.7), and Alabama (28.3) than in California (8.8), Nevada (9.8), and Utah (10.1).

“Education can function as a ‘personal firewall’ that protects more highly educated people from undesirable state-level contexts, while increasing the vulnerability of less educated individuals,” Huang says.

Nearly 59 million people in the US have arthritis, and at least 15 million of them experience severe joint pain because of that condition. Severe joint pain is associated with diminished range of motion, disability, and mortality.

While existing research on the social determinants of pain has relied primarily on individual-level data, individuals are embedded in social contexts, such as a specific US state.

Different states can have dramatically different policies that affect many aspects of life including opportunities, resources and social relationships, which can in turn influence individuals’ pain, a potential influence that has gone largely unexplored in previous research.

“Very little research has examined the geography of chronic pain, and virtually none has examined the role of state-level policies in shaping pain prevalence,” says coauthor Hanna Grol-Prokopczyk, associate professor of sociology. “We were excited to identify state characteristics that reduce residents’ risk of pain.”

The current study does so by combining data on nearly 408,000 adults (ages 25-80) from the 2017 Behavioral Risk Factor Surveillance System with state-level data about SNAP programs (formerly known as food stamps), Earned Income Tax Credits, income inequality, social cohesion (relationship strength among community members), Medicaid Generosity Scores, and tobacco taxes.

Although SNAP programs exist in all 50 states, some states offer more expansive benefits to qualifying residents than others. States with more generous SNAP benefits had a lower prevalence of pain. The same was true for states with greater social cohesion, indicating that both material resources and social functioning play critical roles in shaping pain risk.

“The increase in the generosity of SNAP benefits could potentially alleviate pain by promoting healthier eating habits and alleviating the life stress associated with food insecurity,” says Huang. “Social factors such as conflict, isolation, and devaluation are also among the ‘social threats’ that can lead to physical reactions such as inflammation and immune system changes.”

In addition to providing new information on pain disparities across states, the paper might also fuel a reorientation of pain research that puts equal emphasis on macro- and individual-level factors, according to Huang.

“Chronic pain can—and should—be addressed through macro-level policies, as well as through individual-level interventions,” Huang says. “This study also implies that pain research in general should move towards a greater understanding of the macro contextual factors that shape pain and pain inequalities.”

The study is published in the journal PAIN.

Source: University at Buffalo

A new model clarifies why millions of years ago more animal species from Asia made the leap to the Australian continent than vice versa.

The climate in which the species evolved played an important role, researchers report.

If you travel to Bali, you won’t see a cockatoo, but if you go to the neighboring island of Lombok, you will. The situation is similar with marsupials: Australia is home to numerous marsupial species, such as the kangaroo and the koala. The further west you go, the sparser they become.

While you will find just two representatives of these typically Australian mammals on the Indonesian island of Sulawesi, you will search in vain for them on neighboring Borneo. Australia, on the other hand, is not home to mammals that you will typically find in Asia, such as bears, tigers, or rhinos.

This abrupt change in the composition of the animal world already caught the eye of the British naturalist and co-​discoverer of evolutionary theory Alfred Russell Wallace, who traveled through the Indo-​Australian Archipelago from 1854 to 1862 to collect animals and plants. He described an (invisible) biogeographical line running between Bali and Lombok and Borneo and Sulawesi that marked the westernmost distribution of Australian fauna.

Migration stepping stones

Biodiversity researchers have long been fascinated by this abrupt change of creatures along the Wallace Line. How these distribution patterns came about, however, has not yet been clarified in detail.

One explanation is plate tectonics. Forty-​five million years ago, the Australian Plate began to drift northwards and slid under the mighty Eurasian Plate. This brought two land masses closer together that had previously been far apart. It became easier for land creatures to colonize one continent from the other. Tectonic movements also gave rise to the creation of countless (volcanic) islands between the two continents, which animals and plants used as stepping stones to migrate westwards or eastwards.

But why more species found their way from Asia to Australia—countless poisonous snakes, thorny lizards (Moloch horridus), hopping mice (Notomys sp.), or flying foxes bear witness to this—than the other way round has been a mystery until now.

In order to better understand this asymmetrical vertebrate distribution along the Wallace Line, researchers led by Loïc Pellissier, professor of ecosystems and landscape evolution at ETH Zurich, created a new model that combines reconstructions of the climate, plate displacements between 30 million years ago and the present day, and a comprehensive data set for around 20,000 birds, mammals, reptiles, and amphibians that are recorded in the region today.

Wildlife in Australia

In the new study in Science, the researchers show that adaptations to the climates in the areas of origin are partly responsible for the uneven distribution of Asian and Australian faunal representatives on both sides of the Wallace Line.

In addition to plate tectonics, the environmental conditions that prevailed millions of years ago were decisive for the exchange between the two continents. Based on simulations, the researchers found that animals originating from Asia were more likely to “hop” across the Indonesian islands to reach New Guinea and northern Australia.

These islands featured a tropically humid climate, which they were comfortable with and had already adapted to. The Australian wildlife was different, having evolved in a cooler climate that had become increasingly drier over time, and was therefore less successful in gaining a foothold on the tropical islands than the fauna migrating from Asia.

The Asian climate thus favored creatures that reached Australia via the tropical islands of the faunal region known as Wallacea, especially those that could tolerate a wide range of climates. This made it easier for them to settle on the new continent.

“The historical context is crucial for understanding the biodiversity distribution patterns observed today and was the missing piece of the puzzle explaining the enigma of Wallace’s line,” says first author Alexander Skeels, a postdoctoral researcher in Pellissier’s group.

Biodiversity crisis

Traits of species that evolved in tropical habitats include faster growth and higher competitiveness to enable them to withstand the pressure of coexistence with many other species.

In harsher climates, such as the colder and drier regions of Australia, organisms usually have to evolve special adaptations to cope with drought and heat stress. These include behavioral adaptations such as nocturnal activity and physiological adaptations to minimize water loss.

“Many Australian frogs bury themselves in the ground and remain dormant for long periods for this reason,” Skeels says. “Something that is rare in tropical frogs.”

The findings are important for the researchers. “They make it clear that we can only understand today’s distribution patterns of biodiversity if we include the geological development and climatic conditions of prehistoric times in our considerations,” says Pellissier.

The heritage of long past epochs has shaped the patterns of biodiversity right up to the present. It also helps us to understand why more species are found in the tropics today than in temperate latitudes.

“To fully understand the distribution of biodiversity and the processes that maintain it in the present, we need to find out how it came about,” Pellissier  says.

This is especially true in biogeography because the exchange of species between continents continues to take place regularly and at an alarming rate today as humans move animals and plants around the planet. These species can become invasive on other continents and harm the ancestral fauna and flora.

“Knowing the factors that influence exchange on long time scales is important to understanding why species can become invasive on more recent time scales. In the current biodiversity crisis, this can help us to better assess the consequences of human-​induced invasions,” Skeels says.

Source: ETH Zurich

Women, racial and ethnic minorities, and individuals identifying as lesbian, gay, bisexual, transgender, and queer are disproportionately affected by workplace mistreatment in academic medicine, a study finds.

This mistreatment negatively affects their mental health, the findings show.

The study, which appears in the Journal of the American Medical Association, looked specifically at three aspects of workplace mistreatment in academic medicine—sexual harassment, cyber incivility, and negative workplace climate—and whether they differ by gender, race and ethnicity, and LGBTQ+ status. Additionally, the study examined whether these factors are associated with faculty mental health.

Researchers surveyed a total of 830 faculty members who received National Institutes of Health career development awards in 2006–09 and remained in academia. Experiences were compared by gender, race and ethnicity, and LGBTQ+ status.

The study found that high rates of sexual harassment, cyber incivility, and negative workplace climate disproportionately target marginalized individuals, including women, those whose race or ethnicity has been underrepresented in medicine, and members of the LGBTQ+ community, and these experiences were associated with poorer mental health.

“Understanding the nature and frequency of experiences with harassment is the essential first step to inform a broader cultural transformation process,” says Reshma Jagsi, chair of the radiational oncology department at Emory University School of Medicine. “Cultural transformation of the medical profession is critical to foster civil work environments within which the best and brightest members of society can thrive in their pursuit of the admirable mission to promote human health through care delivery, research, and education.”

Key findings show that women were more likely than men to experience sexual harassment, including gender harassment and unwanted sexual attention.

Of the women surveyed, 71.9% reported that they experienced gender harassment during the past two years, compared to 44.9% of men. Women rated both the general and diversity workplace climate as worse than men and reported certain forms of incivility, sexist comments, and sexual harassment when using social media professionally. In addition, mental health ratings were lower for women, and this difference appeared partly explained by differences in culture experiences.

“The findings suggest that even while women’s representation in the medical field has improved, their experiences reflect marginalization,” says Jagsi. “These stressors lead to a lack of psychological safety, communicate unbelonging, and affect mental health, compromising the vitality of these critical contingents of the professional workforce.”

Of the individuals who identified as LGBTQ+, 13% reported experiencing sexual harassment while using social media professionally versus 2.5% of those who identify as cisgender or heterosexual.

In addition, respondents with races and ethnicities underrepresented in medicine rated the diversity climate more negatively than white respondents and reported certain forms of cyber incivility and racist comments when using social media professionally.

Together, these results suggest an ongoing need for specific interventions to transform culture in academic medicine.

The authors of the study state in JAMA: “The highest rates of sexual harassment occur in organizations that are perceived to tolerate such behavior. Organizations that proactively develop, disseminate, and enforce sexual harassment policies are least likely to harbor such behaviors. These efforts must go beyond formalistic and symbolic legal compliance to engage workers from the ground up and leaders from the top down to ensure meaningful culture change.

“Opportunities to share organizational wins and best practices abound, including the NASEM’s Action Collaborative, the Association of American Medical Colleges’ Group on Women in Medicine and Sciences, and myriad others in professional specialty societies. The findings from the current study should motivate increased attention and resources toward these efforts.”

This study had support from the National Institutes of Health.

Additional coauthors of the study are from Emory; the College of Medicine at Drexel University; and the Schools of Business and Medicine at Duke University.

Source: Emory University