Category: Science

A new tool and technique uses “vortex ultrasound,” a sort of ultrasonic tornado, to break down blood clots in the brain.

The approach worked more quickly than existing techniques to eliminate clots formed in an in vitro model of cerebral venous sinus thrombosis (CVST), according to a new study.

“Our previous work looked at various techniques that use ultrasound to eliminate blood clots using what are essentially forward-facing waves,” says Xiaoning Jiang, co-corresponding author of the paper in the journal Research. “Our new work uses vortex ultrasound, where the ultrasound waves have a helical wavefront.

“In other words, the ultrasound is swirling as it moves forward,” says Jiang, professor of mechanical and aerospace engineering at North Carolina State University. “Based on our in vitro testing, this approach eliminates blood clots more quickly than existing techniques, largely because of the shear stress induced by the vortex wave.”

“The fact that our new technique works quickly is important, because CVST clots increase pressure on blood vessels in the brain,” says Chengzhi Shi, co-corresponding author and an assistant professor of mechanical engineering at Georgia Institute of Technology. “This increases the risk of a hemorrhage in the brain, which can be catastrophic for patients.

“Existing techniques rely in large part on interventions that dissolve the blood clot. But this is a time-consuming process. Our approach has the potential to address these clots more quickly, reducing risk for patients.”

CVST occurs when a blood clot forms in the veins responsible for draining blood from the brain. Incidence rates of CVST were between 2 and 3 per 100,000 in the United States in 2018 and 2019, and the incidence rate appears to be increasing.

“Another reason our work here is important is that current treatments for CVST fail in 20-40% of cases,” Jiang says.

The new tool consists of a single transducer that is specifically designed to produce the swirling, vortex effect. The transducer is small enough to be incorporated into a catheter, which is then fed through the circulatory system to the site of the blood clot.

For proof-of-concept in vitro testing, the researchers used cow blood in a 3D-printed model of the cerebral venous sinus.

“Based on available data, pharmaceutical interventions to dissolve CVST blood clots take at least 15 hours, and average around 29 hours,” Shi says. “During in vitro testing, we were able to dissolve an acute blood clot in well under half an hour.”

During any catheterization or surgical intervention there is a potential risk of harm, such as damaging the blood vessel itself. To address this issue, the researchers performed experiments applying vortex ultrasound to animal blood vein samples. Those tests found no damage to the walls of the blood vessels.

The researchers also conducted tests to determine whether the vortex ultrasound caused significant damage to red blood cells. They found that there was not substantial damage to red blood cells.

“The next step is for us to perform tests using an animal model to better establish the viability of this technique for CVST treatment,” Jiang says. “If those tests are successful, we hope to pursue clinical trials.”

“And if the vortex ultrasound ever becomes a clinical application, it would likely be comparable in cost to other interventions used to treat CVST,” says Shi.

Bohua Zhang, a PhD student, Huaiyu Wu, a postdoctoral researcher, both at NC State, and Howuk Kim, a former PhD student at NC State now on faculty at Inha University, are co-lead authors of the paper. Additional coauthors are from Georgia Tech, the University of Michigan, the University of Pittsburgh Medical Center, UNC Chapel Hill, and NC State.

The National Institutes of Health and the National Science Foundation funded the work.

Source: NC State

Product recommendations that people hear rather than read have a greater influence on their behavior, research indicates.

In the spring of 2018, Shwetha Mariadassou and Chris Bechler, both graduate students at Stanford Graduate School of Business, learned that people generally perceive someone as more intelligent and competent when they convey spoken information rather than delivering the same message in writing.

As she and Bechler chatted after class, Mariadassou recalls, “We wondered, ‘What would happen if you apply this to recommendations?’” Would hearing a recommendation for a product or service influence consumers’ decisions differently? Would they be more likely to buy something based on the word of a smart speaker over a website?

“Voice technology is such a fast-growing technology segment right now,” Mariadassou says. “We wanted to see what would happen when we present recommendations in both modalities.”

So Mariadassou, who is pursuing her PhD in marketing, spearheaded a research project to investigate. She believed there is “a general perception that people act on auditory and visual information the same way”—and wanted to explore this assumption.

Audio vs. text recommendations

With Bechler, now a professor at the University of Notre Dame’s Mendoza College of Business, and Stanford marketing professor Jonathan Levav, Mariadassou ran a series of studies in which participants encountered the same information in different forms, including computer-generated audio that sounded like a smart speaker. This was meant to mimic real-world situations—for instance, Siri can be programmed to “read” a blurb aloud or display it in a text.

The researchers were surprised that, across the board, auditory recommendations for products like brownies, blenders, and beer were more influential than textual ones. Their findings appear in the journal Psychological Science.

“In theory, this shouldn’t yield any difference in behavior,” Levav writes in an email. “Hearing that you should drink the pale ale beer or reading that you should drink the pale ale beer is really one and the same. The fact that it leads to psychologically different experiences that are significant enough to lead to a change in behavior is not something you would expect.”

The effect was small but strong enough to demonstrate a “consistent effect of auditory power,” Mariadassou says. It was a bit difficult to pinpoint why it was happening, however. The researchers believe the power of auditory information has to do with its ephemeral nature—”it seems like there’s this sort of fundamental need to act on information that’s going away,” she says. Bechler agrees: “When something disappears, it creates a kind of urgency to respond.”

The researchers tested this assumption in a scenario where a recommendation was delivered visually, with each word disappearing shortly after it appeared. In this case, the subjects were just as likely to follow the recommendation as when it was delivered via audio.

Artificial voices will do

These findings could have important implications for how companies try to reach customers. While many brands spend a lot to place their products at the top of visual Google search results, Mariadassou says, it might be worthwhile to focus on auditory search results, which can come through a Google Home or an Alexa speaker.

Prior academic research suggests that the source of an auditory message is important: Authentic human voices are deemed more competent and intelligent than computer-generated ones. “The reason for that is because of the paralinguistic cues in a human voice, like intonation and pitch and volume,” Mariadassou says. “These convey this uniquely human capacity for thinking and feeling.” The team found that while people considered human voices more intelligent than digital voices, they still found messages delivered by artificial voices more compelling than those put in writing.

There has been a recent push to look at “how differences in modality affect the perceptions of the speaker,” Levav notes. However, he thinks this new research “breaks ranks” with the literature “by looking at the effect on the recipient of the information.”

There are limitations to these findings, of course. The messages used in the experiments were short and simple. A longer, more complex spoken message might not hold the same weight. Also, the form of the message is just one factor that drives decision-making.

Another important factor is the time-sensitive nature of recommendations. In these experiments, subjects made decisions shortly after receiving the information. “There are very few things in psychology that last beyond the immediate context in which a stimulus occurs,” Levav says. “Here you hear something and are given a chance to act on it; the information is salient and is useful at that moment. Later on, the information is less salient, so therefore also less influential.” It is unclear whether people would make the same choice if there were more time to decide.

Regardless, Bechler says, this research can help us better understand the connection between “consuming information—whether it’s listening to a podcast or reading the newspaper—and how that relates to evaluating choices when purchasing a product or service.”

“We say, ‘Hey, you should focus on these auditory kinds of platforms.’”

Source: Hope Reese for Stanford University

Dollar stores are now the fastest-growing food retailers in the contiguous United States—and have doubled their share in rural areas, according to a new study.

Households with more purchases at dollar stores also tend to be lower-income and headed by people of color. The study in the American Journal of Public Health could have meaningful implications for nutrition policy.

Food and beverages stocked by dollar stores are typically lower in nutrients and higher in calories, while only a small percentage of such shops carry fresh produce and meats. Their growing footprint, especially in the remote South, is also important: These regions already have higher baseline levels of obesity and food insecurity.

“Dollar stores play an increasingly important role in household food purchases, yet research on them is lacking. Many localities have established policies such as zoning laws aiming to slow dollar store expansion even though we don’t fully understand the role that they play,” says first author Wenhui Feng, a professor of health care policy and assistant professor of public health and community medicine at Tufts University School of Medicine. “Our study is one of the first to use nationally representative data to see the role of dollar stores at the household level.”

Rural road trips sparked interest in the topic for the researchers. While completing her doctoral program, Feng vacationed throughout the United States, traveling remote highways that were dotted with dollar stores.

“It was surprising to see this one type of business dominated many areas that I visited. I was intrigued,” says Feng.

Senior author Sean Cash, a professor in global nutrition and associate professor at the Friedman School of Nutrition Science and Policy, had a similar experience visiting his small hometown in upstate New York, where he observed residents crowding the local dollar store for groceries.

Their new research confirms the anecdotes. The pair, and coauthor Elina T. Page from the US Department of Agriculture’s Economic Research Service, analyzed how Americans use dollar stores to access food by analyzing food-purchase data from the IRI Consumer Network, a nationally representative panel of about 50,000 households.

The data captured purchases from 2008 until 2020. It painted a provocative picture of nutritional divides, with households headed by people of color, households in rural areas, and households with lower incomes increasingly reliant on dollar stores.

In general, as people’s income goes up, they spend less of their budget at dollar stores, the researchers found. But they also found that in rural and low-income areas, people spend on average more than 5% of their food budget at dollar stores. In particular, rural non-Hispanic Black households spend 11.6% of their food budgets in dollar stores. Households in the rural South also spend in large numbers.

“The South is a hot spot,” says Cash, a food economist. “The dollar-store business model originated in the South. They have more distribution centers there, and consumers there have supported this growth.”

It’s a notable evolution: Dollar stores once focused primarily on personal care and craft items. Now, they’re expanding to offer prepackaged, shelf-stable food items. These items might be convenient, but they often have suboptimal nutritional value.

“When you start to look at race and ethnicity, there are some implications about equity in terms of people’s access to healthy food,” Feng says.

While dollar stores don’t tend to specialize in fresh foods and produce, they do fill a void that can’t be ignored, especially for people who live in remote areas. In some ways, their rise is actually a positive development, providing consumers with food options in low-access areas.

On the other hand, the recent growth in dollar store food expenditures raises concerns that such stores could force out local grocers through competitive pricing, the researchers write—leaving consumers with limited, less healthy options.

The two plan to focus on health and dietary outcomes in the future, highlighting the types of food typically purchased at dollar stores. “We are now working on a study to see how the healthfulness of the foods purchased in dollar stores compared to other retail outlets,” Feng says.

While dollar stores could be ripe for food-policy intervention, the pair are careful to point out that dollar stores likely won’t overtake supermarkets anytime soon.

“Our data clearly show dollar stores are the fastest-growing format in terms of their share of the food dollar. At the same time, even in the groups that are most impacted in income, racial, and geographic demographics, it’s still 10% or less,” Cash says.

The USDA Cooperative Agreement and a Tufts University Springboard Award supported the work. The USDA Agriculture and Food Research Initiative (AFRI) conference grant program supported a food access workshop the researchers conducted.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the US Department of Agriculture.

Source: Kara Baskin for Tufts University

A significant number of nursing homes at risk for hurricane-related flooding may be inadequately prepared, a new study finds.

One in 10 nursing homes in US coastal regions is at risk of exposure to severe hurricane-related flooding. Nursing home residents are disproportionately more susceptible than the general population to injury and death due to environmental disasters.

Researchers used publicly-available data from the Centers for Medicare & Medicaid Services (CMS) to study the relationship between local exposure risk to hurricanes and emergency preparedness across nursing homes in various coastal regions.

They found that preparedness differed considerably, highlighting the need for standardized emergency measures that protect all vulnerable, at-risk residents.

“This project is at the intersection of medicine and climate,” says Kaitlin Throgmorton, data librarian for the health sciences at Cushing/Whitney Medical Library at Yale University and collaborator of the study, published in JAMA Network Open. “We’re trying to understand how nursing homes are responding to various climate threats through using fully open data.”

Smaller-scale studies have suggested a lack of emergency preparedness. The team hoped to better understand the correlation between potential inundation from hurricanes and preparedness at a large geographic scale using a sample of nearly 6,000 nursing homes along the Atlantic and Gulf coasts.

They geocoded the homes and evaluated facility characteristics as well as exposure risk to potential hurricane-related inundation using maps data from the National Hurricane Center. Then, they used the data to see if exposed nursing homes were likelier to have stronger preparedness.

The study found that approximately 10% of those sampled were at risk of experiencing hurricane-related inundation, and about 30% also had a critical emergency preparedness deficiency.

While at-risk facilities on the western Gulf Coast were more likely to have stronger preparedness, to the team’s surprise, this correlation did not exist in other regions. In the mid-Atlantic region, they observed a higher prevalence of emergency preparedness deficiencies among at-risk facilities.

“In our analysis, we found that nursing homes in the western Gulf Coast seem to be responsive to local environmental risks,” says Natalia Festa, research fellow with the National Clinician Scholars Program and Yale Program on Aging. “But in other regions, that does not seem to be the case.”

The team believes that the western Gulf Coast may be better prepared due to regulatory reforms following Hurricane Katrina, and that these facilities could potentially serve as an exemplar of emergency preparedness for at-risk nursing homes in other parts of the country.

“But there is additional research that’s needed to understand the mechanisms underlying the patterns that we observed,” Festa adds.

Furthermore, the study shows how fully open data can be used to learn more about health care facilities’ preparedness for environmental hazards.

“We’ve been able to promote open data work and also show the impact of what we can learn and what we can advise on from a policy perspective,” says Throgmorton.

The team plans to extend its work by evaluating nursing home emergency preparedness for other regionally concentrated environmental hazards throughout the United States.

Source: Isabella Backman for Yale University

Any unseasonably hot day—no matter the time of year—can lead to a rush of gun violence, research finds.

When temperatures sizzle, so do tempers. Across the United States, headlines lamenting a summer spike in shootings—a “gun violence emergency” in Portland, Oregon, “another summer of mayhem” in Philadelphia—have become a depressing feature of the season.

According to the researchers, mitigating the impacts of climate change and helping residents adjust to rising temperatures could help curb shootings.

Published in the journal JAMA Network Open, the study finds a consistent relationship between higher temperatures and higher risk of shootings in 100 of the country’s most populated cities.

The comprehensive study reveals that nearly 7% of shootings can be attributed to above-average daily temperatures, even after adjusting for seasonal patterns. The paper’s findings—the first to show that heat-attributable shootings are a nationwide problem—indicate that the Northeast and Midwest regions experience the sharpest increases in gun violence on hotter-than-normal days. Gun violence is the leading cause of death among children and teens—a situation that only worsened during the pandemic.

“Our study provides strong evidence that daily temperature plays a meaningful role in gun violence fluctuations,” says study senior author Jonathan Jay, assistant professor of community health sciences and director of Boston University’s Research on Innovations for Safety and Equity (RISE) Lab. “Even though some regions showed larger or smaller effects, the general pattern is remarkably consistent across cities.”

As climate change threatens to raise daily temperatures even more, the researchers say their findings underscore the need for ongoing policies and programs that acclimate communities to heat and mitigate the risk of heat-attributable gun violence.

“Our study really highlights the importance of heat adaptation strategies that can be used all year, as well as a need for specific regional awareness and attention in regions where this relationship is strongest,” says Vivian Lyons, study lead author and a research scientist in the Social Development Research Group at the University of Washington’s School of Social Work.

For the study, the research team used publicly available data from the Gun Violence Archive, a national repository of gun violence information. They analyzed daily temperatures and more than 116,000 shootings, from 2015 to 2020, in 100 of the most populous US cities with the highest number of assault-related shootings. Accounting for seasonality and regional climate differences, they found that 7,973 shootings were attributable to above-average temperatures.

The temperatures associated with increased gun violence varied considerably across cities. For example, both Seattle and Las Vegas experienced the highest elevated risk of gun violence during days when the temperature soared within the 96th percentile range of average daily temperatures—but for Seattle, that temperature was 84 degrees, while in Las Vegas, it was 104 degrees.

“Cities with high rates of firearm violence should continue to implement firearm-prevention strategies broadly, including credible messenger programs and hospital-based violence intervention programs,” Lyons says. “What our study suggests is that for cities with more heat-attributable shootings, implementing heat adaptation strategies at the community level—such as greening efforts that have been effective at reducing urban heat islands and have some association with reductions in firearm violence—may be particularly important.”

So, what might be driving this association between heat and gun violence? “It could be that heat causes stress, which makes people more likely to use aggression,” says Jay, who’s also a partnering faculty member at the BU Center for Climate and Health. “Or it could be that people are more likely to get out on warmer days and have more interactions, which creates more opportunities for conflict and violence. Most likely, it’s a combination of both.”

Regionally, heat-attributable gun violence may be most pronounced in the Northeast and Midwest due to sharper fluctuations in temperature in those areas, even within seasons, or because cities in those regions are less acclimated to heat, the researchers say. But those regions are also more racially segregated than other parts of the country. The study findings should be interpreted within the context of structural racism and racial inequities in exposure to gun violence and heat, says Jay.

“The Northeast and Midwest regions are where we see some of the starkest differences in the built environment and other resources, according to race—to me, these inequities are the most interesting and important direction of this work,” Jay says. “We know that segregation and disinvestment lead communities of color, especially Black communities, to have greater exposure to adverse environmental conditions that contribute to gun violence risk, such as abandoned buildings, liquor stores, lack of green space, and more intense urban heat islands.”

Healthy tree canopy and other heat mitigation strategies can serve as part of a mission that’s “part racial justice, part climate change mitigation, and part gun violence prevention,” he says. “These are all urgent issues where we need to continue to partner with communities and work across disciplines.”

The researchers will next study differences in heat-related gun violence among neighborhoods in a project funded by the National Collaborative on Gun Violence Research.

The study had funding from Washington state; Jay also had support from the Boston University Clinical & Translational Science Institute.

Source: Boston University

In an important step toward a medical technology that could help restore independence of people with paralysis, researchers find the investigational BrainGate neural interface system has low rates of associated adverse events.

More than two decades ago, a team researchers set out with an ambitious goal to provide people with paralysis a revolutionary neurotechnology capable of turning thoughts about movement into actual action, using a tiny device that would one day be implanted in the surface of the brain.

Their work led to an ongoing effort to create the BrainGate brain-computer interface, designed to allow clinical trial participants with paralysis to control assistive devices like computers or robotic limbs just by thinking about the action they want to initiate.

Now, after decades of advancements, researchers are getting their best glimpse yet at the safety profile for this promising technology and what it means for long-term use by people affected by neurologic disease or paralysis.

The team’s new study analyzes more than 17 years of safety data on clinical trials testing the BrainGate technology. The study found a low rate of adverse events associated with the implanted brain-computer interfaces (BCIs) and concluded that the technology should continue to be evaluated for its potential to help people with paralysis regain lost neurologic function.

“In the largest ongoing trial of intracortical brain-computer interfaces, the interim safety profile reported today supports the possibility that these systems may become restorative neurotechnologies for people with paralysis,” says Leigh R. Hochberg, an engineering and brain science professor at Brown University, a critical care neurologist at Massachusetts General Hospital, and director of the BrainGate academic consortium leading the development and testing of the technology.

The new study is an important step for the BrainGate consortium and other BCI research as the current BrainGate clinical trial enters its 14th year.

“Intracortical brain-computer interfaces have so much promise for restoring communication and mobility,” says Hochberg, who also directs the VA Rehabilitation Research and Development Center for Neurorestoration and Neurotechnology in Providence, Rhode Island.

“Translating these advances in neural engineering to patient care will depend largely on whether the devices are accompanied by an acceptably low degree of risk.”

The BrainGate device is a type of BCI that is implanted in a part of the brain that controls limb movement. The microelectrode array—called a “Utah” array—is smaller than a contact lens and is placed into the surface of the motor cortex. It works by detecting neural signals associated with intended movements, sending them out to a small nearby computer that then uses algorithms to translate the signals into movement commands.

The ultimate goal of BrainGate is to restore communication, mobility, and independence for people with tetraplegia. Previous studies by BrainGate researchers have shown that the BCI can enable people to move robotic arms or even move their own paralyzed arm and hand.

The new BrainGate study evaluated a total of 12,203 days of safety data from 14 clinical trial participants with quadriparesis resulting from spinal cord injury, brainstem stroke, or ALS. Participants were ages 18 to 75 and were enrolled in BrainGate’s trials between 2004 to 2021. In that span, the study found, there were 68 device-related adverse events—the most common was skin irritation around the small portion of the device on top of a user’s head that connects the neural sensor array implanted in the brain to the nearby neural decoding system.

There were six serious adverse events determined to be related to the BrainGate device or surgical procedure. Two participants, both of whom had a history of traumatic brain injury, had brief post-operative seizures, which were easily treated. The researchers say none of the adverse events documented in the study were unanticipated, resulted in permanently increased disability, required removal of the device, or led to infections in the nervous system.

Data from the clinical trials came from seven sites across the US, including Mass General and the Providence VA Researchers at Mass General led the study in collaboration with colleagues from Brown, the VA, Stanford University, and several other institutions in the BrainGate consortium. The scientists write in the study that while the safety profile is a big step forward, there is still much work to be done to reach their ultimate goals for the technology.

“Overall, we are reassured by our findings over the past 17 years that the investigational BrainGate Neural Interface system is being deployed safely,” the researchers write. “Both our group and others continue to work on components and systems that would permit [BCIs] to become fully implanted, available to users around-the-clock, and incorporating a suite of design characteristics previously proposed.”

“In the future, I hope that BrainGate becomes an option for everyone with paralysis,” says John Donoghue, a professor at Brown. “The golden day would be when somebody who is paralyzed gets a BrainGate-like system implanted, and they go play basketball.”

The new study appears in Neurology. The research received support from the US Department of Veterans Affairs, the National Institutes of Health, Howard Hughes Medical Institute, Massachusetts General Hospital, the Carney Institute for Brain Science at Brown University, and several additional funders noted in the paper.

Source: Brown University

Young Asian and white men without college education are paid more—sometimes far more—than both Black men and women of all racial groups, according to a new study.

The study finds that young Black men with no college education earn barely half of what their Asian American and white counterparts make. Latinx, Asian, and Black women lag even further.

“…rather than wasting time blaming workers’ choices or attitudes, we might get further by identifying discriminatory labor market processes.”

“Earnings are an important factor to study because they’re related to other outcomes, like health, engagement with the criminal justice system and family development,” says study leader Byeongdon Oh, a postdoctoral researcher in the University of California, Berkeley’s Social Sciences D-Lab. “So we focus on the non-college population at an early age. They are already disadvantaged economically—they have very low earnings. If there’s a sizable racial or ethnic earnings disparity in this population, there may be severe consequences.”

The study appears in the journal Sociology of Race and Ethnicity. It provides the first detailed look at the earnings of young adults with no college experience as their working lives take shape.

In recent years, about one-third of young Americans have stopped their education after high school. That projects to roughly 1 million less-educated young people every year entering a job market that increasingly requires advanced education and training to earn even a middle-class salary. Latinx and Black people are over-represented in this group.

To understand their experience, Oh and colleagues Daniel Mackin Freeman and Dara Shifrer from Portland State University studied data from the High School Longitudinal Study of 2009, tracing racial and ethnic earnings disparities among men and women who had never attended college. In 2016, they were in their early 20s.

“Striking” was the word the authors used to describe the earnings gaps revealed in the core data:

• Young Asian American men with no college education earned an average of $24,837 in 2016, followed by white men at $22,056 and Latinx men at $17,984. Young Black men averaged just $12,573—barely half the wages earned by Asian Americans and whites.
• A similar, but less severe, disparity was evident among young women with no college experience. White women on average earned $14,766, followed by Latinx women at $12,465, Asian American women at $10,935, and Black women at $10,871.
• The gap between these women and men was vast, with young Black women on average earning only 44 cents for every dollar earned by Asian American men with similar levels of education.

How to explain these racial and gender gaps in earning?

Oh says the data did not allow the researchers to determine the causes. They did find, however, that a range of possible factors—from family background and home location to high school grades and criminal records—rarely account for the earnings gaps.

But, he explains, racial discrimination in the workforce cannot be ruled out as the cause.

Oh suggests that complex social and economic factors may sort people of color into lower-paying job sectors, but the estimated earnings gaps among groups of people in the same occupation are still dramatic. These earning disparities, he says, may reflect employer bias against women and Black men.

The findings “suggest that, like their more educated counterparts, young non-college-educated women may face pernicious earnings discrimination in the labor market, regardless of their race/ethnicity,” the authors write.

They add: “The results may indicate that employers devalue the work of young Black men without a college education to a greater degree than they do the work of white, Latinx, and Asian men without a college education.”

According to Oh, the pay disparity between Asian and white men on one side and Black men on the other may actually be worse than the data suggest. A disproportionate number of young men who did not go to college are Black. A disproportionate number of young Black men have been incarcerated, he explains, and incarcerated men were not tracked in the survey data.

“And so our findings on the earnings gap are conservative—it may be larger,” he says.

The new study opens up a range of new questions for Oh and other researchers. Understanding the experience of the young workers would require more targeted surveys and in-person interviews. Those would allow the researchers to understand whether discrimination is to blame, and if so, how it works, Oh says.

“I hope the contribution of our research is to make people ask why we have these striking earnings gaps,” he says. “Then, rather than wasting time blaming workers’ choices or attitudes, we might get further by identifying discriminatory labor market processes.”

Source: UC Berkeley

Toddlers will go out of their way to help dogs, especially pups struggling to access out-of-reach treats and toys, according to new research.

The finding shows that young children notice and understand dogs’ goals, using that knowledge to help them.

“It’s been known for a long time that toddlers will go out of their way to help struggling humans, even strangers,” says Henry Wellman, professor emeritus of psychology at the University of Michigan.

“But perhaps such altruism is specially evolved for and targeted toward other humans (who after all might help them back). But no, it applies to other animals too, like dogs they will never see again.”

Wellman and colleagues conducted experiments with three dogs—Fiona, Henry, and Seymour—at the University of Michigan’s child laboratory between 2015 and 2020 to determine if young children spontaneously helped a pet.

The researchers studied 97 children (51 girls and 46 boys) ages 2 and 3 years, 44 of whom had dogs as pets. In the lab, the children met one of the friendly dogs in an enclosed baby gate fence while a treat or toy was placed outside it. Dogs reacted naturally, either showing interest (either pawing or begging) in accessing the item or ignoring it.

Children provided dogs with out-of-reach items 50% of the time when dogs showed interest rather than ignored items, indicating sensitivity to the dog’s goals, the study shows.

In addition, children who lived with pet dogs were more likely to provide items to the pups in the experiment if two scenarios were present: the dogs were lively and engaged rather than subdued, and if the item was a treat rather than a toy.

“These findings lend support to our hypothesis that children’s early-developing proclivities for goal-reading and prosociality extend beyond humans to other animals,” says lead author and alumna Rachna Reddy, who is now a postdoctoral fellow in evolutionary anthropology at Duke University.

The researchers believe children’s willingness to help goes beyond dogs; it likely extends to cats, birds, horses, pigs, ducks, sheep, and more. But demonstrating that will take future research, Wellman says.

The study appears in the journal Human-Animal Interactions.

Source: University of Michigan

Red squirrels that gamble at the game of reproduction outperform their counterparts, even if it costs them in the short term, research finds.

Imagine overhearing the Powerball lottery winning numbers, but you didn’t know when those numbers would be called—just that at some point in the next 10 years or so, they would be. Despite the financial cost of playing those numbers daily for that period, the payoff is big enough to make it worthwhile.

Animals that live in highly variable environments play a similar lottery when it comes to their Darwinian fitness, or how well they are able to pass on their genes.

Natural selection favors female squirrels that have large litters in years when food is abundant because they contribute lots of babies to the gene pool, says Lauren Petrullo, lead author of the study and a postdoctoral research fellow in biopsychology at the University of Michigan.

“We were surprised to find that some females have large litters in years when there won’t be enough food for their babies to survive the winter,” she says. “Because it’s biologically expensive to produce offspring, we wanted to know why these females make what appears to be an error in their reproductive strategy.”

The red squirrels studied live in the Canadian Yukon and experience a “mast year,” or boom in their main food source—seeds from the cones of white spruce trees—once every four to seven years. Squirrels forecast the large mast crop of food before it occurs and increase litter sizes in the months prior, ensuring better future survival for their babies and better fitness for themselves.

“There is a constant tug-of-war between the trees and the squirrels at our study site,” Petrullo says, “with each player trying to deceive the other for its own fitness gain.”

Petrullo and Ben Dantzer, associate professor of psychology and of ecology and evolutionary biology, used data collected by the Kluane Red Squirrel Project, a collaborative, 34-year-old field study involving the University of Michigan, the University of Colorado, the University of Alberta, and the University of Saskatchewan.

“This is exciting because it suggests that squirrels are eavesdropping on the trees.”

“Each year, we collect data on how many babies squirrels produce and how many spruce cones the squirrels eat,” Dantzer says.

The scientists quantified the reproduction of female squirrels during both food booms and busts, discovering differences in their fitness whether they gambled with their reproductive strategy or not. While some squirrels played it safe by keeping litter sizes small each year, those that took a “pie in the sky” approach by having large litters even when food was scarce enjoyed greater lifetime fitness if they got to experience a mast year, the research showed.

Unlike the Powerball example, though, squirrels aren’t guaranteed to eventually win.

“In some ways, this strategy of gambling with litter sizes is like playing with fire,” Petrullo says. “Because the average squirrel lifespan is 3.5 years and masts only happen every four to seven, a female could potentially be sabotaging her fitness by having too many babies in low-food years, hoping for a mast when she may die before she ever gets to experience a mast at all. This could be pretty costly.”

Alternatively, for squirrels, the cost of not gambling at all in the game of reproduction can be insurmountable if they end up missing their shot at the jackpot.

“It’s essentially impossible for a female to recuperate the fitness costs of not ramping up reproduction in a mast year, so the stakes are extremely high,” Petrullo says.

Females that increased litter sizes in low-food years did take a short-term hit to their fitness. But they were more likely to increase litter sizes if and when they experienced a mast, taking home the ultimate prize of greater lifetime reproductive success, she says.

The squirrels’ best bet, according to the researchers, is to take their chances and suffer short-term fitness costs in order to avoid the unmatched cost of missing the fitness jackpot completely.

“Determining the relative costs of different types of errors is key to understanding why animals make what look to us like mistakes,” Petrullo says.

Scientists are still unsure exactly how the squirrels are able to forecast future food production. The animals may be eating parts of the spruce trees that affect their physiology and alter the number of babies they produce, Dantzer says.

“This is exciting because it suggests that squirrels are eavesdropping on the trees, but we still have much more to do to solve this puzzle,” he says.

Because many animals use cues about things like food in their environment to make reproductive decisions, and the reliability of these cues is declining due to global climate change, scientists also wonder how the costs of these types of errors will alter what is the best reproductive strategy.

“If the predictability of a food boom is reduced and squirrels can no longer forecast the future, this could impact the number of squirrels out there in the Boreal forest,” Dantzer says. “This could be problematic given that squirrels are prey for many predators.”

The research, which appears in Science, had partial funding from the National Science Foundation and the Natural Sciences and Engineering Research Council of Canada.

Source: University of Michigan

Warming waters and heat waves have contributed to the loss of an economically and culturally important fishery, the production of bay scallops, according to a new study.

As climate change intensifies, heat waves are becoming more and more common across the globe. In the face of such repeated events, animals will acclimate, migrate, or perish.

Since 2019, consecutive summer mass die-offs of bay scallops in the Peconic Estuary on Long Island, New York, have led to the collapse of the bay scallop fishery in New York and the declaration of a federal fishery disaster, with landings down more than 99%.

The findings in Global Change Biology reveal that extreme summer temperatures, becoming more frequent under climate change, exacerbate the vulnerability of bay scallops to environmental stress and has played a role in the recurrent population crashes.

The study reports the mass die-off of all scallops at a New York site in 2020, when an eight-day summer heat wave event coincided with repeated episodes of low oxygen. Yet, scallops at locales with higher oxygen or lower temperatures survived. Further investigation that year confirmed that the combination of high temperatures and low oxygen reduced feeding and energy reserves, causing mortality in ecosystem and laboratory scenarios.

“Global warming is happening at an uneven pace in space and time. It just so happens that summer water temperatures in the Northeast are increasing at a rate more than three times the global average, leaving organisms adapted to cooler temperatures endangered,” says senior author Christopher Gobler, chair of coastal ecology and conservation at Stony Brook University.

By using a combination of satellite temperature and long-term environmental records, field and laboratory experiments, and measurements of scallop heartbeat rates in an ecosystem setting because scallops heartbeat rates vary with water temperatures, the researchers demonstrated that coastal waters from New York to Massachusetts—home to the nation’s northern bay scallop fisheries—are rapidly warming and that bay scallops have become increasingly susceptible to the combination of high temperatures and impaired water quality.

The bay scallop fishery was formerly one of the largest shellfisheries on the East Coast and has progressively vanished from regions south of New York. With the New York fishery collapsed, the only remaining commercial US fishery is in Massachusetts.

The study also reveals that although Massachusetts waters are still in the safe range for bay scallops, they have warmed at a rate even faster than New York waters and could be threatened in the future.

Stephen Tomasetti, a graduate of Stony Brook’s School of Marine and Atmospheric Sciences and currently a visiting assistant professor of environmental studies at Hamilton College, points to other examples of heat-induced mass mortality on the East Coast, like the loss of lobsters in Long Island Sound and blue mussels in coastal bays south of Delaware.

“Commercial shellfisheries are a vital part of our blue economy, and shellfish habitats are changing rapidly,” he says. “Mitigating further warming by transitioning to clean energy is critical. But while these global efforts are underway, committing to practices that will improve our local water quality like reducing nutrient pollution is also important.”

Warmer waters physically hold less oxygen, so increasing the baseline oxygen levels in the estuary by improving water quality will help offset future oxygen loss from increased temperature.

The authors warn that warming in the Northeast US is projected to continue at a faster pace than the global average. The populations of mobile species like fish can respond by moving to waters with more tolerable temperatures.

But for populations of bay scallops and other economically important shellfish species, movement is limited by their ability to disperse through spawning and the availability of suitable habitat. Populations forced to cope with temperature extremes may be more vulnerable to mass mortality events.

Source: Stony Brook University