Category: Science

A new study identifies a way to tame the self-destructive tendencies of certain killer T cells.

In a promising form of immunotherapy known as CAR T-cell (chimeric antigen receptor) therapy, the patient’s T cells are engineered to better recognize and attack antigens on the surface of cancer cells.

In treatments currently approved for use in battling lymphoma and leukemia, however, the therapy has a drawback: Amidst the cancer-killing frenzy, many engineered T cells become tainted with the remnants of cancer antigens, which causes them to turn on other T cells. This eventually depletes the body of cancer-fighting cells and opens the door for a recurrence of cancer.

Simply fusing a molecular tail onto the engineered T cells used in therapy, researchers say, can inhibit their proclivity to attack each other. The study appears in the journal Nature Immunology.

“It’s like putting a sword back in the sheath after it has done its work,” says Sidi Chen, associate professor of genetics at Yale University School of Medicine and senior author of the study.

For the study, the team—which was led by co-first authors Xiaoyu Zhou and Hanbing Cao—fused CTLA-4 cytoplasmic tails (CCTs) to engineered CAR T cells. CCTs are a portion of a naturally occurring human protein, known as CTLA-4, which is known to keep the immune system in check by regulating T cells. Researchers observed that the cells fused with these tails were less exhausted and survived longer than CAR T cells without the tails.

“The CAR T cells with the engineered tails were less reactive but more persistent” in killing cancer cells, says Zhou, a postdoctoral associate in Chen’s lab.

Chen says it would be relatively easy for existing companies to fuse CCTs to CAR T cells, and that improvements in therapy might help expand treatments to solid tumors as well.

The work had support from the National Institutes of Health, the US Department of Defense, and several foundations.

Source: Yale University

A new study highlights a key problem with computer security guidelines and outlines ways to improve them.

At issue are the computer security guidelines that organizations like businesses and government agencies provide their employees. These guidelines are generally designed to help employees protect personal and employer data and minimize risks associated with threats such as malware and phishing scams.

“As a computer security researcher, I’ve noticed that some of the computer security advice I read online is confusing, misleading, or just plain wrong,” says Brad Reaves, corresponding author of the study and an assistant professor of computer science at North Carolina State University. “In some cases, I don’t know where the advice is coming from or what it’s based on. That was the impetus for this research. Who’s writing these guidelines? What are they basing their advice on? What’s their process? Is there any way we could do better?”

For the study, researchers conducted 21 in-depth interviews with professionals who are responsible for writing computer security guidelines for organizations including large corporations, universities, and government agencies.

“The key takeaway here is that the people writing these guidelines try to give as much information as possible,” Reaves says. “That’s great, in theory. But the writers don’t prioritize the advice that’s most important. Or, more specifically, they don’t deprioritize the points that are significantly less important. And because there is so much security advice to include, the guidelines can be overwhelming—and the most important points get lost in the shuffle.”

The researchers found that one reason security guidelines can be so overwhelming is that guideline writers tend to incorporate every possible item from a wide variety of authoritative sources.

“In other words, the guideline writers are compiling security information, rather than curating security information for their readers,” Reaves says.

Drawing on what they learned from the interviews, the researchers developed two recommendations for improving future security guidelines.

• First, guideline writers need a clear set of best practices on how to curate information so that security guidelines tell users both what they need to know and how to prioritize that information.
• Second, writers—and the computer security community as a whole—need key messages that will make sense to audiences with varying levels of technical competence.

“Look, computer security is complicated,” Reaves says. “But medicine is even more complicated. Yet during the pandemic, public health experts were able to give the public fairly simple, concise guidelines on how to reduce our risk of contracting COVID. We need to be able to do the same thing for computer security.”

Ultimately, the researchers find that security advice writers need help.

“We need research, guidelines, and communities of practice that can support these writers, because they play a key role in turning computer security discoveries into practical advice for real world application,” Reaves says.

“I also want to stress that when there’s a computer security incident, we shouldn’t blame an employee because they didn’t comply with one of a thousand security rules we expected them to follow. We need to do a better job of creating guidelines that are easy to understand and implement.”

The study will be presented at the USENIX Symposium on Usable Privacy and Security, which takes place August 6-8 in Anaheim, California. Additional authors of the study are from NC State, George Washington University, and Paderborn University.

Source: NC State

A rodenticide, a neurotoxicant called bromethalin, can bioaccumulate in birds of prey, new findings show.

In 2020, Tufts Wildlife Clinic Director Maureen Murray published a study that showed 100% of red-tailed hawks tested at the clinic were positive for exposure to anticoagulant rodenticides (ARs). Such exposure occurs when these chemicals are used to kill mice or rats, which eat the poison, and the birds eat the poisoned prey.

“We understand very well that ARs can remain active once they’ve been ingested by the prey, and when a bird of prey or other species ingests that animal, the predator will be poisoned by the residues. But with bromethalin, adequate studies to prove or disprove whether that type of secondary poisoning can happen don’t exist yet,” says Murray, an associate clinical professor at Cummings School of Veterinary Medicine. “The point of our new study is to answer a simple question: would we be able to find evidence of bromethalin exposure in birds of prey coming into the clinic? And the answer is yes, we found it.”

Murray and coauthor Elena Cox, a fellow in wildlife medicine and education, sampled the birds in the same way as the birds in the 2020 AR study. The birds of prey were from the same geographic population of birds in which Murray has found high exposure to ARs over time and were from the same four species of hawks and owls that were included in her previous studies. They found evidence of bromethalin exposure in about 30% of the birds of prey that were sampled.

The new study appears in the journal Environmental Pollution.

How does bromethalin work?

In 2008, the United States Environmental Protection Agency (EPA) tightened the rules around the sale of ARs, prompted by evidence of exposure among children, pets, and “non-target wildlife” (animals not meant to be harmed by the poison). The regulations partially went into effect in 2011.

“After that decision, some manufacturers of rodent poisons sold through general consumer outlets changed the active ingredient in their products from an AR to bromethalin, which hadn’t really been present in these types of consumer products prior to the regulations going into effect,” says Murray. Bromethalin can also be used by pest management professionals (PMPs). A 2017 study by Murray explored what products PMPs in Massachusetts used.

ARs work by thinning the blood and cause the animal to slowly bleed to death. A single feeding of a second-generation AR potentially contains enough poison to kill a rodent. However, it takes a few days for the animal to die, and in the meantime, they may be eaten by birds of prey. Even after the animal dies, its carcass contains residues that can be lethal for scavengers.

Bromethalin works by interfering with a metabolic process called oxidative phosphorylation, or how an individual cell creates energy. When that process is disrupted, the cells can’t produce the fuel to keep their normal processes functioning correctly, such as regulating fluid balance, or the amount of fluid inside the cell versus outside of the cell. When the cell can’t regulate that fluid balance anymore, it causes accumulation of fluid in abnormal spaces.

The organ system most quickly and significantly affected by that is the central nervous system. The animal ends up with fluid accumulation and increased pressure in the brain and potentially in the spinal cord. Depending on the dose, this can result in poor coordination, seizures, depressed mentation, and/or death.

Bromethalin toxicosis

To look for bromethalin exposure Murray says fat is the best tissue to analyze for the active metabolite, desmethylbromethalin. However, exposure to a poison doesn’t always cause clinical signs or death, she said.

While AR toxicosis is pretty easy to diagnose, Murray says, that is not the case with bromethalin. With AR toxicosis the animal is hemorrhaging, their red blood cell count is very low, and their blood can’t clot. However, there’s an antidote, and in less severe cases, it can be treated, she says.

“Diagnosing bromethalin toxicosis is tricky because it causes symptoms that are very non-specific. Many things can cause the same signs, such as lead poisoning, head trauma, or the current outbreak of highly pathogenic avian influenza,” says Murray. “If a red-tailed hawk comes in with a certain set of neurologic signs, right now my first guess is the bird has avian influenza until it tests negative.”

It’s also not straightforward to prove bromethalin toxicosis after death because bromethalin does not result in visible changes to organs and it does not always cause microscopic changes to tissues. For these reasons, it’s hard for the researchers to say whether bromethalin exposure is responsible for a particular bird’s clinical signs or death.

Bald eagles, too?

Murray and Cox also are coauthors of a case report that will publish later this year in the Journal of Wildlife Diseases about bromethalin exposure and possible toxicosis in a bald eagle (Haliaeetus leucocephalus). While they could not definitively prove bromethalin toxicosis in the eagle, the exclusion of the most likely other causes of death supports the possibility. The paper “shows exactly how hard it is to prove bromethalin poisoning beyond a shadow of a doubt,” Murray says.

There’s no specific treatment for bromethalin toxicosis, she adds, and no antidote, just supportive care. Still, being able to diagnose bromethalin poisoning would help clinicians determine the prognosis for an animal, because depending on the amount it consumed, it could potentially recover.

“In mammalian species, if an animal has ingested a sub-lethal amount, they may show paralysis, usually of their hind legs. In a bird, that may look to us like spinal trauma, which has a poor prognosis. But if we could prove the bird had been exposed to bromethalin, the prognosis might actually be better for that bird to recover,” Murray says.

Further monitoring and study of the potential risk of bromethalin to wildlife species is needed, the authors conclude. Also, Murray adds, the findings show the ongoing, widespread exposure of birds of prey in the northeastern United States to ARs, underscoring the need for reevaluation of mitigation measures intended to decrease this risk. The EPA is currently evaluating new mitigation measures to reduce exposure and mortality in wildlife from ARs, and the authors hope their study supports the need for further protective measures for ARs as well as for continued monitoring of wildlife species to evaluate ongoing risk and effectiveness of mitigation efforts.

The research had support from the Animal Welfare Institute and the Ruby Memorial Research Fund administered by Cummings School of Veterinary Medicine at Tufts University. Complete information on authors, funders, methodology, and conflicts of interest is available in the published paper. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funders.

Source: Tufts University

People with Alzheimer’s disease and other forms of dementia end up in hospital emergency rooms 1.4 million times a year, a new study shows.

Together, they make up nearly 7% of all emergency visits for any reason by people over age 65. And compared with their peers who don’t have dementia, these patients have twice the rate of seeking emergency care after an accident or a behavioral or mental health crisis, the researchers show.

With about 6 million Americans currently estimated to have dementia, the study suggests there’s a lot of opportunity to prevent future emergency visits by better supporting dementia caregivers, the researchers say.

Once a person with dementia is in the emergency department, it can be a very disorienting experience.

The findings, published in JAMA Neurology, could help inform efforts to support family caregivers and nursing facility staff in reducing patients’ risks of injury, and preventing the agitation, aggression, and distressing behaviors that people with dementia can experience, says lead author Lauren B. Gerlach, a geriatric psychiatrist at Michigan Medicine, the University of Michigan’s academic medical center.

Dementia in the emergency room

“While dementia is thought of as a cognitive or memory disorder, it is the behavioral aspects of the disease such as anxiety, agitation, and sleep disturbances that can cause the most stress for caregivers and patients alike. Emergency departments are often not the right place to manage these behaviors,” she says. “We really need to do better to support caregivers so there are options other than seeking emergency care.”

Once a person with dementia is in the emergency department, it can be a very disorienting experience, Gerlach says. “This is especially true in the context of a busy ED where visits can last many hours and patients may have difficulty understanding what is occurring or communicating their needs,” she says. “Even routine blood draws from unfamiliar staff can be a very scary experience for a patient with advanced dementia.”

To make matters worse, behavioral symptoms common in this group can lead to treatment with potentially dangerous sedative medications.

Emergency department patients with dementia received antipsychotic medications at more than twice the rate as other emergency patients over age 65 during their visit, the study shows. Such drugs, often used to sedate people with dementia and calm their behavioral symptoms, can carry major risks if used long-term—including increasing the risk of fall accidents and death as highlighted in warnings from the US Food and Drug Administration.

Long after the emergency has ended, the concern is that these newly started antipsychotic and sedative medications in could then continue to be prescribed long-term, putting patients with dementia at further risk, says Gerlach.

Extra tests

The study also adds evidence that older adults with dementia may be treated differently in the emergency department. People with dementia were much more likely than those without to receive a urine test or a CT scan of their head.

“Difficulty in the ability of patients with dementia to communicate their symptoms verbally can make it challenging to distinguish what is causing their symptoms,” Gerlach says. “Is it related to a change in their environment, difficulty between the patient and their caregiver, or an underlying medical issue?”

For instance, urinary tract infections can cause pain that can lead to agitation or aggression in a person with dementia, who may not be able to express what they’re feeling. However, these challenges can sometimes lead to indiscriminate laboratory testing and imaging, Gerlach adds.

Caregiver stress, caregiver education

The data for the study came from the National Hospital Ambulatory Medical Care Survey conducted by the Centers for Disease Control and Prevention, and include information on people over 65 no matter what form of health care coverage they had.

There has not been much research on emergency care for people with dementia, despite the fact that clinicians and caregivers who care for such patients know from experience that emergencies can be common, say Gerlach and Matthew A. Davis, an associate professor in the School of Nursing and Michigan Medicine’s learning health sciences department.

Caregiver stress and burnout from a lack of respite or support may play a role in the need for seeking emergency care in people with dementia, says Gerlach, an assistant professor in the University of Michigan psychiatry department.

She sees promise in a new proposed Medicare rule that would allow health care teams to get reimbursed for sessions that educate family caregivers—including on how to prevent or soothe behavioral symptoms among their loved ones.

One approach to this, called DICE, is now available online to dementia caregivers anywhere. Gerlach also recommends the caregiver support programs and information offered by the Alzheimer’s Association, and videos from UCLA Health, available in multiple languages, to her patients’ caregivers to help manage these behaviors.

Those who live with people who have dementia should also consider safety upgrades in the home to reduce fall risks and the chance of other injuries. “It’s important to match the home environment to their needs and ability, which could reduce the risk of emergency care being needed,” Gerlach says.

The rise of geriatric-focused emergency departments or areas within larger emergency departments may also help, Gerlach notes, but they are not available in all areas.

It’s also important for families to be realistic about when it’s time to seek emergency services for their loved one with dementia.

If physical aggression or falling risk gets to be too much for a family caregiver to handle, the safety of the patient and the caregiver must outweigh the desire to keep them at home, Gerlach says. “But before that, there is a lot we can do in the outpatient setting to help prevent crisis and the need for emergency care,” she says.

The National institute on Aging, part of the National Institutes of Health, funded the work.

Source: University of Michigan

Researchers have created a new web app called Self-Talk with Superhero Zip to help children develop skills like self-awareness and emotional management.

At first, some parents were wary: An audio chatbot was supposed to teach their kids to speak positively to themselves through lessons about a superhero named Zip. In a world of Siri and Alexa, many people are skeptical that the makers of such technologies are putting children’s welfare first.

In Self-Talk with Superhero Zip, the chatbot guides pairs of siblings through lessons. The research team from the University of Washington found that, after speaking with the app for a week, most children could explain the concept of supportive self-talk (the things people say to themselves either audibly or mentally) and apply it in their daily lives. And kids who’d engaged in negative self-talk before the study were able to turn that habit positive.

The team published its findings at the 2023 Interaction Design and Children conference. The app is still a prototype and is not yet publicly available.

The team saw a few reasons to develop an educational chatbot. Positive self-talk has shown a range of benefits for kids, from improved sport performance to increased self-esteem and lower risk of depression. And previous studies have shown children can learn various tasks and abilities from chatbots. Yet little research explores how chatbots can help kids effectively acquire socioemotional skills.

“There is room to design child-centric experiences with a chatbot that provide fun and educational practice opportunities without invasive data harvesting that compromises children’s privacy,” says senior author Alexis Hiniker, an associate professor in the Information School.

“Over the last few decades, television programs like Sesame Street, Mister Rogers, and Daniel Tiger’s Neighborhood have shown that it is possible for TV to help kids cultivate socioemotional skills. We asked: Can we make a space where kids can practice these skills in an interactive app? We wanted to create something useful and fun—a Sesame Street experience for a smart speaker.”

The researchers began with two prototype ideas with the goal to teach socioemotional skills broadly. After testing, they narrowed the scope, focusing on a superhero named Zip and the aim of teaching supportive self-talk. They decided to test the app on siblings, since research shows that children are more engaged when they use technology with another person.

Ten pairs of Seattle-area siblings participated in the study. For a week, they opened the app and met an interactive narrator who told them stories about Zip and asked them to reflect on Zip’s encounters with other characters, including a supervillain. During and after the study, kids described applying positive self-talk; several mentioned using it when they were upset or angry.

By the end of the study, all five kids who said they used negative self-talk before had replaced it with positive self-talk. Having the children work with their siblings supported learning in some cases, but some parents found the kids struggling to take turns while using the app.

The length of these effects isn’t clear, the researchers note. The study spanned just one week and the tendency for survey participants to respond in ways that make them look good could lead kids to speak positively about the app’s effects. Future research may include longer studies in more natural settings.

“Our goal is to make the app accessible to a wider audience in the future,” says lead author Chris (Yue) Fu, a doctoral student in the iSchool. “We’re exploring the integration of large language models—the systems that power tech like ChatGPT—into our prototype and we plan to work with content creators to adapt existing socioemotional learning materials into our system. The hope is that these will facilitate more prolonged and effective interventions.”

Additional coauthors are from the University of Southern California, Meta Reality Labs, and the University of Washington.

The Jacobs Foundation and the Canadian Institute for Advanced Researchers funded the work.

Source: Stefan Milne for University of Washington

Breast milk from each person contains a unique assemblage of antibodies that are surprisingly stable throughout lactation and across pregnancies, according to a new study.

Since a baby’s early immunity is directed by antibodies from breast milk, the new research provides insight into why protection against different infections varies among infants and why some babies develop a life-threatening gut disease called necrotizing enterocolitis (NEC).

“While each milk donor in our study had very different antibody profiles from one another, we found that antibodies from the same donor were quite similar over time—even across the span of months,” says senior author Timothy Hand, associate professor of pediatrics and immunology at the University of Pittsburgh School of Medicine and the UPMC Children’s Hospital of Pittsburgh.

“This means that if a baby’s parent happens to lack particular antibodies, such as those that fend off NEC, they’re never going to receive that immunity. This could help explain why some babies get NEC and others don’t.”

NEC is a devastating inflammatory gut disease that mainly affects preterm infants; NEC, which has been linked with a family of bacteria called Enterobacteria is about two to four times more frequent in formula-fed babies than those fed breast milk.

Before their immune system matures, babies are protected from harmful bacteria by antibodies transferred via the placenta and through breast milk. These antibodies bind to bacteria in the intestine, preventing them from invading the host.

In an earlier study, Hand and his team found that Enterobacteriaceae in fecal samples of healthy babies were mostly bound by maternal antibodies. In contrast, infants who went on to develop NEC had more bacteria that escaped being bound. Hand suspected that variation in babies’ immunity to NEC was because different mothers passed along different antibodies. The new study lends support to this idea.

For the current study in the Journal of Experimental Medicine, Hand and his team analyzed donor breast milk from the Human Milk Science Institute and Biobank in Pittsburgh and Mommy’s Milk Human Milk Research Biorepository in San Diego. Using an array of different bacteria, they measured which strains each donor’s antibodies bound to.

“Individual donors’ antibody profiles looked completely different, which is what we had expected but were able to show for the first time,” says Hand. “During pregnancy, B cells travel from the intestine to the mammary gland, where they start making antibodies. The mom is trying to protect her infant using antibodies that she uses to protect her own intestine.

“Different women have led different lives, have different microbiomes, and have encountered different infections, so it makes perfect sense that breast milk antibodies would reflect that variability.”

Throughout the breastfeeding period, a person’s milk changes from highly concentrated protein-rich colostrum into mature milk. To learn whether antibody composition changes, too, Hand and his team compared breast milk from the same donors over time. They also looked at the same donors over multiple pregnancies.

“Not only were antibodies similar in donors across one pregnancy, they were also remarkably stable between infants,” says Hand. “This suggests that when B cells arrive in the breast tissue, they don’t leave. This is important for understanding how babies acquire immunity and how they deal with infections.”

The researchers also found there was no difference in antibodies between those who delivered their baby preterm and full-term.

Other studies indicate that a parent’s own milk is the best food for reducing a premature baby’s likelihood of developing NEC, but if that isn’t available, donor milk is an important substitute or supplement. This milk is sterilized to kill bacteria, but whether this process also affects antibodies had not been tested.

Hand and his team found that pasteurization reduced antibody levels in donor milk. While this likely means that infants fed donor milk receive fewer antibodies than those who get milk directly from their mother, Hand says that more research is needed to understand what levels of antibodies are protective against diseases like NEC.

In the future, better understanding of specific bacteria that are most dangerous for preterm infants at risk of NEC could help researchers develop antibodies that could be added to formula or breast milk to boost immunity.

Source: University of Pittsburgh

New technology could lower the cost of capturing carbon dioxide from all types of emissions, a new study shows.

The tech is a potential game-changer for both industries looking to adapt to evolving greenhouse gas standards and for the emergent energy-transition economy.

As reported in the journal Nature, the system can directly remove carbon dioxide from sources ranging from flue gas to the atmosphere by using electricity to induce a water-and-oxygen-based electrochemical reaction.

This technological feat could turn direct air capture from fringe industry—there are only 18 plants currently in operation worldwide—into a promising front for climate change mitigation.

Most carbon-capture systems involve a two-step process: First, high- pH liquids are used to separate the carbon dioxide, which is acidic, from mixed-gas streams such as flue gas. Next, the carbon dioxide is regenerated from the solution through heating or by injecting a low-pH liquid.

“Once the carbon dioxide is trapped in these solvents, you have to regenerate it,” says Haotian Wang, assistant professor of chemical and biomolecular engineering, materials science and nanoengineering, and chemistry at Rice University.

“Traditional amine scrubbing methods require temperatures of 100-200 degrees Celsius (212-392 Fahrenheit). For calcium carbonate-based processes you need temperatures as high as 900 Celsius (1652 Fahrenheit).

“There are literally no chemicals produced or consumed with our process. We also don’t need to heat up or pressurize our device, we just need to plug it into a power outlet and it will work.”

Another drawback of current carbon-capture technologies is their reliance on large-scale, centralized infrastructure. By contrast, the system developed in the Wang lab is a scalable, modular, point-of-use concept that can adapt to a variety of scenarios.

“The technology can be scaled up to industrial settings—power plants, chemical plants—but the great thing about it is that it allows for small-scale use as well: I can even use it in my office,” Wang says.

“We could, for example, pull carbon dioxide from the atmosphere and continuously inject that concentrated gas into a greenhouse to stimulate plant growth. We’ve heard from space technology companies interested in using the device on space stations to remove the carbon dioxide astronauts exhale.”

The reactor can continuously remove carbon dioxide from a simulated flue gas with efficiency above 98% using a relatively low electricity input.

“The electricity used to power a 50-watt light bulb for an hour will yield 10 to 25 liters of high-purity carbon dioxide,” says lead author Peng Zhu, a chemical and biomolecular engineering graduate student.

Wang notes that the process has “no carbon footprint or a very limited footprint” if powered by electricity from renewable sources such as solar or wind.

“This is great news considering that renewable electricity is becoming more and more cost-effective,” Wang says.

The reactor consists of a cathode set up to perform oxygen reduction, an oxygen evolution reaction-performing anode and a compact yet porous solid- electrolyte layer that allows efficient ion conduction. An earlier version of the reactor was used to reduce carbon dioxide into pure liquid fuels and reduce oxygen into pure hydrogen peroxide solutions.

“Previously, our group focused mainly on carbon dioxide utilization,” Zhu says. “We worked on producing pure liquid products like acetic acid, formic acid, etc.”

According to Wang, during the research process, Zhu observed that gas bubbles flowed out of the reactor’s middle chamber along with the liquids.

“At the beginning, we didn’t pay a lot of attention to this phenomenon,” Wang says. “However, Peng observed that if we applied more current there were more bubbles. That’s a direct correlation, which means that something not random is happening.”

The researchers realized that the alkaline interface generated during reduction reactions at the reactor’s cathode side interacted with carbon dioxide molecules to form carbonate ions. The carbonate ions migrate into the reactor’s solid-electrolyte layer where they combine with protons resulting from water oxidation at the anode side, forming a continuous flow of high-purity carbon dioxide.

“We randomly discovered this phenomenon during our previous studies,” Wang says. “We then tuned and optimized the technology for this new project and new application. We’ve spent years of continuous work on this type of electrochemical device.

“Scientific discovery often requires this patient, continuous observation and the curiosity to learn what’s really going on, the choice not to neglect those phenomena that don’t necessarily fit in the experimental frame.”

The National Science Foundation, the Robert A. Welch Foundation, and the David and Lucile Packard Foundation supported the research.

Source: Rice University

A new study reveals new clues about the subtle but previously poorly understood evolutionary dance happening between temperatures and changes in the size of animal body parts.

The new research offers important insights about how animals, particularly birds, may adapt to the rapid rise in temperatures driven by global climate change.

For the study in Nature Communications, the researchers looked at nearly 7,000 species of terrestrial nonmigratory birds—which is nearly two-thirds of all bird species—and focused on how bird morphology has evolved along gradients in ambient temperature and other agents of selection.

Two widely accepted “rules” in biology indicate that as local temperatures change, animals are likely to adjust their heat transfer capabilities by changing the size of their bodies and extremities.

Biologist Carl Bergmann’s rule states that colder climates spawn bigger bodies because they help retain heat while smaller bodies help shed it. As a result, a polar bear is more than 2½ times as tall at the shoulder as a sun bear from equatorial regions.

Zoologist Joel Asaph Allen’s rule deals with extremities, such as limbs, ears, and beaks, stating that animals in colder climates tend to have smaller extremities because extremities tend to have more surface than volume and are uniquely suited to shed heat. For example, arctic hares have evolved short legs and ears, whereas desert jackrabbits have evolved very long legs and ears.

“The problem is that everything we know about ecology tells us that changing the size of bodies and extremities can be problematic,” says lead author Carlos Botero, an associate professor of integrative biology at the University of Texas at Austin.

For example, if body size decreases, birds may not be able to hunt the same food as their ancestors. Similarly, if the average size or shape of a bill changes, birds may become less efficient foragers or have trouble producing typical mating calls.

It is not surprising that many prior studies have failed to find evidence for these predictions and that these so-called biological rules are currently controversial. The new study could clarify that debate by showing that although the patterns that Bergmann and Allen predicted occur in the wild, the two separate mechanisms complement each other within avian lineages.

The current study’s researchers also wanted to figure out why a small number of bird families still follow the rules that most others appear to circumvent. They found that in many of those cases, the species involved had bumped up against some kind of natural constraint.

For example, owls have responded to temperature gradients primarily through body size adjustments such that the arctic great gray owl has a body nearly 2 feet long, whereas its relative, the Central American pygmy owl, which lives in the tropics, is only about 5 inches long. These birds, however, have highly specialized beaks that are almost the same size.

“When your hunting tactics depend on the size and shape of your beak, that structure is the last thing you want to change,” says first author Justin Baldwin, a graduate student of Botero’s at Washington University in St. Louis. “As a result, it is likely less problematic to only change body size instead.”

Another example involves flycatchers. The tufted tit-tyrant flycatcher lives in the coldest parts of South America and has a tiny beak, which helps it retain heat. Its cousin, the boat-billed flycatcher, has a comparatively massive bill and lives in warmer areas of the tropics. Both have diminutive body sizes.

“When you’re already really small and you need to shed heat, it may be hard to get any smaller, so the next best available option is to expand the bill,” Baldwin says.

Joan Garcia-Porta of Washington University in St. Louis and Universitat de Barcelona also contributed to the research. The University of Texas at Austin and Washington University in St. Louis funded the work.

Source: UT Austin

Only 43% of parents have set their child up for a patient portal, an online tool allowing communication between patients and medical providers, and others may not be optimizing portal use, according to a new poll.

For many busy families, online access to a child’s health provider for medical advice, health records, or prescription refills could be a convenient option.

“Patient portals offer a wide range of benefits, including decreasing unnecessary hassles for providers and patients and improving access to both the medical staff and a child’s medical information,” says Sarah Clark, co-director of the University of Michigan Health C.S. Mott Children’s Hospital National Poll on Children’s Health.

“Given all the conveniences portals offer, it’s surprising that over half of parents have not set one up for their child, most commonly because they don’t see a need for it. This report suggests many parents may not be aware of all the potential benefits of using a patient portal for children.”

Parents whose children do have a portal tout those perks, with a third polled saying they’ve received advice about their child’s illness, injury, or symptoms through the platform. Nearly all of these parents say they got the level of guidance they anticipated within a reasonable amount of time and usually from the person they expected.

Why some parents skip it

The majority of parents who use the portal for their child have also used the tool to make appointments, view test results, complete pre-visit forms, and request prescription refills. Others use it for telehealth visits, requests for immunization records or forms for school, sports, or camps or for a referral, according to the nationally representative report, which is based on 2,095 responses from parents of children 18 and under.

Still, among parents who did not have a patient portal for their child, a little less than a third said they do not see any need for it, about a quarter did not know it had to be set up, and about a fifth prefer other modes of communication.

Very few parents cited privacy concerns or technical problems but some didn’t think their provider offered a portal option for their child.

“Our poll suggests that pediatric health providers should continue efforts to inform families about the benefits of patient portals, and parents who haven’t set one up should take steps to learn more about portal advantages and how to establish one for their child,” Clark says.

Some providers, she notes, have expressed concerns about parents having unrealistic expectations about how quickly the provider can respond to portal inquiries, including situations where the child may need urgent medical attention.

But providers can do their part to manage these expectations, Clark says. Parents who received instructions from their provider or medical staff on how to use and access the portal reported more benefits, such as it saving them time and hassle.

However, over a third of parents with portals did not receive such guidance—and these parents had the lowest satisfaction ratings on communication with their child’s provider.

“Instructions from the practice on how to optimize portal benefits appear to be the key to helping parents use it effectively and appropriately and increase families’ satisfaction with the experience,” Clark says.

Privacy for teens

Parents of older children should be aware that they may eventually lose access to some of their child’s health information. Among parents who have a portal for their teen, 1 in 3 have noticed differences in what they could see or do on their child’s portal.

These changes are mandated by states’ minor privacy laws, which requires children gain more confidentiality once they reach a certain age. Parents will then have a limited proxy account that doesn’t show them all of a child’s health information.

Clark says these laws are intended to protect the confidentiality of adolescent health care, including services for sexual health, mental health, or substance use. Portal limitations encourage teens to disclose and seek care for health behaviors they may not want known to their parents, such as a pregnancy test or prescription for birth control.

However, among parents who have a portal for their teen, 74% believe parents should retain portal access until the child turns 18. Many health care systems have an option where teens can grant portal access to their guardian, which might appeal to these parents, Clark says.

“Portal limitations are designed to protect the confidentiality of adolescent health care,” Clark says. “Before parents insist their teen give them portal access, or they attempt to get around portal limitations, parents should first consider the implications of their child being reluctant to seek confidential health care services.

“There are also potential benefits of teens actively participating in their own care and taking ownership of their health by learning to interact with providers via the portal.”

Source: University of Michigan

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