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The pathologies underlying brain decline can begin years before symptoms emerge. Can everyday behavior provide warning?Learning your odds of eventually developing dementia — a pressing concern for many, especially those with a family history of it — requires medical testing and counseling. But what if everyday behavior, like overlooking a couple of credit card payments or habitually braking while driving, could foretell your risk?A spate of experiments is underway to explore that possibility, reflecting the growing awareness that the pathologies underlying dementia can begin years or even decades before symptoms emerge.“Early detection is key for intervention, at the stage when that would be most effective,” said Sayeh Bayat, the lead author of a driving study funded by the National Institutes of Health and conducted at Washington University in St. Louis.Such efforts could help identify potential volunteers for clinical trials, researchers say, and help protect older people against financial abuse and other dangers.In recent years, many once-promising dementia drugs, particularly for Alzheimer’s disease, have failed in trials. One possible reason, researchers say, is that the drugs are administered too late to be helpful. Identifying risks earlier, when the brain has sustained less damage, could create a pool of potential participants with “preclinical” Alzheimer’s disease, who could then test preventive measures or treatments.It could also bring improvements in daily life. “We could support people’s ability to drive longer, and have safer streets for everyone,” Ms. Bayat offered as an example.For now, the search for older people who are likely to develop Alzheimer’s or other dementias takes place mostly in research settings, where patients learn their risk status through some combination of genetic testing, spinal taps or PET scans to detect amyloid in the brain, as well as through questions about family history..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}“It’s all about finding people soon enough to intervene and prevent or delay the onset of the disease,” said Emily Largent, a medical ethicist and health policy researcher at the Penn Memory Center in Philadelphia, which undertakes many such studies.Other kinds of predictive tests are on the horizon, including over-the-counter blood tests for tau, another Alzheimer’s biomarker, but are several years away, Dr. Largent said.That leaves methods that are invasive, like spinal taps, or expensive, like PET scans. These approaches can’t be used to screen large groups of people. “They’re not available everywhere,” Ms. Bayat said. “They’re not very accessible or scalable.”But a GPS device in someone’s car could monitor driving behavior almost continuously at low cost, providing so-called digital biomarkers. “Studies have shown that driving changes in people with symptomatic Alzheimer’s,” Ms. Bayat said. “But some changes occur even earlier.”The Washington University study enrolled 64 older adults with preclinical Alzheimer’s, as determined by spinal taps (the results were not shared with participants), and 75 who were deemed cognitively normal.For a year, researchers measured both groups’ driving performance — how often they accelerated or braked aggressively, exceeded or fell well below the speed limit, made abrupt moves — and their “driving space” (number of trips, average distance, unique destinations, trips at night). “Only now, because we have these technologies, can we do this kind of research,” Ms. Bayat said.The study found that driving behavior and age could predict preclinical Alzheimer’s 88 percent of the time. Those findings could spur recruitment for clinical trials and allow interventions — like an alert when a car drifts — to help keep drivers on the road. In areas with inadequate public transportation (which is most areas), that could enhance seniors’ independence.Dr. Jason Karlawish, a geriatrician and co-director of the Penn Memory Center, called the study “provocative” and well designed. “The results suggest that monitoring a real-world, cognitively intense behavior can detect the earliest, subtle signs of emerging cognitive impairment,” he said in an email.Similarly, a study analyzing medical records and consumer credit reports for more than 80,000 Medicare beneficiaries showed that seniors who eventually received a diagnosis of Alzheimer’s disease were significantly more likely to have delinquent credit card payments than those who were demographically similar but never received such diagnoses. They also were more likely to have subprime credit scores.“We were motivated by anecdotes in which family members discover a relative’s dementia through a catastrophic financial event, like a home being seized,” said Lauren Nicholas, the lead author and a health economist at the University of Colorado School of Public Health. “This could be a way to identify patients at risk.”The problems appeared early, with at least two consecutive payments skipped as much as six years before a diagnosis, and subprime credit two and a half years before. Although smaller studies have pointed to an association between self-reported financial mismanagement and dementia, this is the largest and the first to use actual financial data, Dr. Nicholas added.In Japan, researchers have developed a machine-learning tool that scrutinizes phone conversations for signs of preclinical Alzheimer’s. Using audio files recorded during interviews last year, they compared healthy patients’ vocal features — pitch, intensity, silent intervals — with those with Alzheimer’s and found that the models could predict cognitive status.IBM researchers have picked up elevated risk in writing tests, finding that word patterns and usage predicted later Alzheimer’s diagnoses. Any of these findings might, one day, be used for early screening.Such approaches raise concerns about privacy, however. “Are people comfortable with a bank or an auto insurance company having and communicating that information?” Dr. Largent asked. “It becomes medical information in the hands of people who are not physicians.”At the Penn Memory Center, where information is indeed in health professionals’ hands, “some people who are cognitively unimpaired, after testing in the clinic, indicate they’d like to be monitored,” she said. “Others find that unbelievably intrusive.”Bioethicists have grappled for years with questions about informing patients of higher-than-normal risk for a feared disease for which there is, still, no effective treatment. Studies have shown that in research settings, results can be communicated safely and effectively. But fears of discrimination and stigma remain.Even using established biomarkers like amyloid in PET scans, these advance findings aren’t definitive, which researchers take pains to point out to patients. “It’s neither necessary nor sufficient to have these risk factors,” Dr. Largent explained. People with elevated amyloid have higher risk but may not progress to cognitive impairment; people without it can nevertheless develop dementia.Still, Dr. Largent said, “I generally think having that information can be useful to people.”In a number of studies, Dr. Largent has examined what happens when dementia risks are disclosed to patients and families. She has found that about one-third of patients respond to the information by changing their health behavior, undertaking legal and financial planning or taking other preparatory steps. “They do things like update their wills, draft advance directives, exercise more, maybe move closer to an adult child,” she said.Paul Gondek, 68, who lives in Philadelphia and teaches social psychology at Drexel University, chose to learn his risk status two years ago, volunteering for several studies at the Penn Memory Center. Alzheimer’s tends to run in families and, having watched his mother’s slow decline from the disease, he knew he had a higher chance of developing it.To Mr. Gondek’s relief, the PET scan showed that he did not have elevated amounts of amyloid in his brain. And a calculated risk score showed that his odds of Alzheimer’s by age 85 were about 19 percent — higher than the 11 percent risk for the general population, but lower than he had feared.If other early indicators were available through driving or financial records or other behaviors and were reliable, he said, “I would want to use them. I’d rather know than not.”

The decline in the mental health of children and adolescents has led to new laws allowing kids to attend to their own self-care.By the time Ben Ballman reached his junior year in high school he was busier — and more anxious — than he had ever been. “I had moments where it felt like the whole world was coming down on me,” he said. “It was definitely a really difficult time.”Before the pandemic shut everything down, his day started at 6:30 a.m., when he woke up to get ready for school. Next came several Advanced Placement courses; then either soccer practice or his job at a plant nursery; studying for the SAT; and various extracurricular activities. He often didn’t start his homework until 11 p.m., and finally went to bed three hours later. Every day it was the same grueling schedule.“It’s not even that I was going above and beyond, it was, ‘This is the bare minimum,’” said Ben, now 18 and a recent graduate of Winston Churchill High School in Montgomery County, Md. “It’s like a pressure cooker that’s locked down. There’s nowhere to escape. Eventually you just kind of burst at some point, or, hopefully, you can get through it.”Faced with high stress levels among adolescents and a mental health crisis that includes worsening suicide rates, some states are now allowing students to declare a mental health day.In the last two years alone, Arizona, Colorado, Connecticut, Illinois, Maine, Nevada, Oregon and Virginia have passed bills permitting children to be absent from school for mental or behavioral health reasons, efforts that were often aided or spearheaded by students.And in March, Utah decided that a “valid excuse” for a student’s absence will now include “mental or behavioral health,” broadening an earlier definition that referred to mental illness. The legislator who sponsored the bill, Representative Mike Winder, a Republican, told the television station KUTV in February that it was his daughter, then a senior at Southern Utah University, who suggested the idea.Late last year the advocacy group Mental Health America surveyed teenagers about the top three things that would be most helpful for their mental health. More than half of the respondents cited the ability to take a mental health break or absence from either school or work. And in a Harris Poll of more than 1,500 teenagers conducted in May of last year, 78 percent of those surveyed said schools should support mental health days to allow students to prioritize their health. Ben, the recent graduate, said that as a high school student he had spoken with classmates who were struggling and needed support but didn’t know where to turn. So he organized a coalition of students to improve mental health services for students in his state. This year he spent months supporting a mental health day bill in Maryland, but it stalled in the State Senate.There is some debate over what constitutes a mental health day and how best to spend it. Just as there isn’t a precise definition for adults, there isn’t a consensus on what it means for children, either. Typically, it is a day to rest, recalibrate and take a break from your regular routine. Unless a state or a school district outlines specific requirements, families can interpret the term broadly.Dr. Harold S. Koplewicz, medical director of the Child Mind Institute and a child and adolescent psychiatrist based in New York City, views mental health days as a joyous occasion: an opportunity to have fun.Ideally, you can use mental health days as a way to celebrate your child’s efforts in school, he said.For example, maybe your child just finished a big project, handed it in, and the next day she said: “I’m exhausted. I want a mental health day.” In that case, taking the day off is “perfectly appropriate,” Dr. Koplewicz said.But don’t use mental health days to help your child avoid situations at school that are making them uncomfortable, he cautioned.Instead, try to pinpoint where that anxiety is stemming from. “Are they avoiding something because it is too challenging? Are they being hurt in some way?” he asked. If your child doesn’t want to be in school at all or is showing symptoms of depression, like insomnia, oversleeping or a lack of interest in normal activities, take time to have a deeper conversation about what’s going on. Depending on the problem, you might need a longer-term solution rather than simply a day or two to recharge.If your child needs time off because they are suffering from crippling anxiety or experiencing a behavioral health crisis, for example, it might not be appropriate for schools or families to label that as a “mental health day” — in fact, doing so might inadvertently minimize mental health disorders, Dr. Koplewicz said.“Sick days are sick days, whether it’s physical or mental,” he added.Taking a day to relax and recharge can be useful at any age, including for preschoolers, who are also susceptible to stress and exhaustion, said Jennifer Rothman, the senior manager of youth and young adult initiatives at the National Alliance on Mental Illness.“Everyone has mental health, everyone,” she said. “Our kids are faced with so many things on a daily basis.”And that was the case well before Covid-19. The state of children’s mental health has worsened over the last decade. Between 2009 and 2019, an increasing percentage of American youth reported feeling sad or hopeless for at least two weeks “to the degree that they could not engage in their usual activities,” the Centers for Disease Control and Prevention reported; and 70 percent of teenagers surveyed by the Pew Research Center in 2018 said anxiety and depression were major problems among their peers.The percentage of students who seriously considered suicide or made a suicide plan has also risen in the last decade. And suicide has become the second leading cause of death among adolescents.The pandemic has further exacerbated some of these problems. Nearly half of the parents surveyed in January by the University of Michigan’s C.S. Mott Children’s Hospital said that their teenagers had shown signs of either a new or worsening mental health condition during the pandemic. And a C.D.C. report found that the proportion of 12- to 17-year-olds visiting emergency rooms for mental health reasons rose 31 percent for most of 2020 compared with 2019.In New York, California and Florida — homes to some of the nation’s largest school districts — there are no state laws specifying that children can take a mental health day. Legislators in each of these states have tried to change that, but those efforts have fallen flat.In the New York City school system, which has more than 1 million students, a day off for mental or behavioral health reasons “would be treated like any other sick day,” Nathaniel Styer, a New York City Department of Education spokesman, said.The phrase “mental health day” might make some kids and parents uncomfortable. With that in mind, the school board in Montgomery County, Md., decided that it will excuse absences taken for “student illness and well-being,” starting in the new school year.“We didn’t want to call it a mental health day, because we know there is still stigma around that,” Karla Silvestre, the school board vice president, told Education Week in June.Schools are also experimenting with other methods beyond mental health days to help students cope with their daily stressors. The Jordan School District in South Jordan, Utah, is using “wellness rooms,” where students can decompress for 10 minutes if they are feeling overwhelmed. And some schools in Colorado have created “oasis rooms,” a student lounge staffed with peer counselors and other resources.Melanie Zhou, 19, who attended high school in Highlands Ranch, Colo., worked alongside other students to create the oasis rooms after a friend died by suicide.“When my friend passed away, I had no idea how to grieve properly,” she said.Much like Ben, Melanie felt that academics were the priority at her school, not self-care. And at home, “mental heath was not talked about very clearly or openly,” she added.One advantage of declaring a “mental health day” and recognizing its importance at the state level is that — ideally — using this kind of language can help families start to have more open conversations about subjects related to mental health, and potentially reduce some of the stigma associated with self-care, Ms. Rothman said.“It doesn’t necessarily mean that you have a diagnosable illness, it just means that you are taking a break,” she added.

Rice University, where more than 95 percent of students are vaccinated, announced a move to remote classes last week after testing showed an alarmingly high number of community members with breakthrough Covid infections.Those results, the university now says, were badly distorted by a testing glitch.Of 4,500 tests administered on the Rice campus, 81 had returned positive results, mostly in vaccinated members of Rice’s community. Even in Houston, where the Delta variant was surging, the results were a surprise. Rice had taken tough efforts to control coronavirus in its community, practically demanding that students, faculty and staff be vaccinated, even as the state of Texas prohibited vaccination mandates. The university also required masks.Further examination revealed that most of the people who appeared to have tested positive were actually negative for Covid, the university now says.When Rice began to examine the cases, it found that the results didn’t make sense, according to a note to the university community on Sunday from Kevin E. Kirby, vice president for administration at Rice. Most of the people who tested positive did not have any symptoms. And the cases were scattered, with no clusters.Rice discovered that the testing provider that reported so many positive results had just switched to using a new test. When 50 of the people who tested positive were retested using different types of tests, all but one of the results came back negative.All the same, Rice says that it plans to stick with its decision to move to remote learning until Sept. 3. According to a university Covid dashboard, Rice now considers only 27 of the 4,500 tests administered on campus since Aug. 13 to have yielded true positive results, not 81.

Although we can survive without a spleen, evidence continues to mount that this abdominal organ plays a more valuable role in our physiological defenses than previously suspected.
“The spleen holds a whole army of immune cells and signaling molecules that can be rapidly mobilized to respond whenever a major injury like a heart attack or viral invasion occurs,” said Ganesh Halade, PhD, an associate professor of cardiovascular sciences at the University of South Florida Health (USF Health) Morsani College of Medicine.
Dr. Halade led a new preclinical study that analyzed the interactions of the lipid mediator sphingosine-1-phosphate (S1P) in the spleen and heart during the transition from acute to chronic heart failure. The researchers discovered new cardiac repair mechanisms to help shed light on spleen-heart coordination of physiological inflammation in a mouse model of heart failure.
The study appeared online August 20 in the American Journal of Physiology- Heart and Circulation.
“Simply put, we showed that the spleen and the heart work together through S1P for cardiac repair,” said principal investigator Dr. Halade, a member of the USF Health Heart Institute. “Our study also suggests that early detection of little or no S1P levels after a heart attack and targeted activation of this bioactive lipid mediator may provide a cardioprotective treatment for patients at high risk of heart failure.”
Dr. Halade and colleagues have defined connections between fatty acids, dysfunctional inflammation control, and heart failure. His laboratory focuses on discovering ways to prevent, delay or treat unresolved inflammation after a heart attack. In this latest study, the researchers turned their attention to where S1P is produced and its role in cardiac repair.
S1P is a lipid mediator dysregulated during inflammatory responses, including heart failure. Moreover, several groups have demonstrated the potential significance of this signaling molecule as a treatment target for heart failure triggered by heart attack and ischemia-reperfusion injury.
The USF Health study captured time-dependent movement of S1P from the spleen through circulating blood plasma to the heart. The work was the first to quantify interactions between S1P and S1P receptor 1 (S1PR1) during the progression from acute to chronic heart failure, Dr. Halade said.
The researchers defined S1P/S1PR1 signaling in both mice and humans with heart failure after a heart attack. The otherwise young, healthy “risk-free” mice had no variable cardiovascular risk factors such as obesity, diabetes, hypertension, and aging commonly seen in a clinical setting. The researchers correlated the physiological data from the cardiac-repair mouse model experiments with what they observed in pathologically failing human hearts.
Among their key findings: Cardiac-specific S1P and S1PR1 levels were reduced in patients with ischemic heart failure. In the risk-free mice, physiological cardiac repair was facilitated by activation of S1P in the heart and the spleen. S1P/S1PR1 signaling increased in both organs from acute through chronic heart failure, helping to promote cardiac repair after heart attack. Increased plasma S1P indicates cardiac repair in the acute phase of heart failure. Selective activation of the S1P receptor in macrophages (immune cells that that help clear inflammation and guide tissue repair) suppressed biomarkers of inflammation and accelerated biomarkers of cardiac healing in mouse cells.”This study provides another example that the spleen should not be underestimated, because it contributes to the foundation of our immune health as well as the root cause of inflammatory diseases, including cardiovascular disease,” Dr. Halade said.
The research was supported by grants from the National Institutes of Health and the U.S. Department of Veterans Affairs. The USF Health team worked with collaborators at the University of Alabama at Birmingham and Hokkaido University, Japan.
Story Source:
Materials provided by University of South Florida (USF Health). Original written by Anne DeLotto Baier. Note: Content may be edited for style and length.

Researchers have found a way to better pinpoint the “golden window” when a womb is ready for pregnancy, in a discovery that could help boost IVF success rates.
It’s long been known that correctly timing an embryo transfer is critical to the chance of achieving pregnancy.
Identifying the right moment in a woman’s cycle with absolute precision remains a challenge however, contributing to low IVF success rates, which remain on average under 50%.
But now RMIT University researchers may have found a way forward, by identifying a Teflon-like molecule that makes the surface of the womb slippery and prevents embryos from implanting.
The team discovered that the levels of this molecule on the womb’s surface decrease at a certain point in the menstrual cycle.
This allows the womb to become stickier, opening the “golden window” for pregnancy success.

A six-month exercise programme helps maintain normal heart rhythm and reduces the severity of symptoms in patients with atrial fibrillation,according to late breaking research presented at ESC Congress 2021.1
“The ACTIVE-AF trial demonstrates that some patients can control their arrhythmia through physical activity, without the need for complex interventions such as ablation or medications to keep their heart in normal rhythm,” said study author Dr. Adrian Elliott of the University of Adelaide, Australia.
Atrial fibrillation (AF) is a heart rhythm disorder that makes the heart beat fast and irregularly. The most common symptoms are palpitations, shortness of breath, light headedness, and fatigue, which can dramatically impact quality of life. Patients have significant risks of stroke and heart failure. The global prevalence of AF is increasing rapidly and is estimated to be over 30 million people,2 while the lifetime risk of the disorder for individuals over the age of 55 may be as high as one in three.3
Exercise-based rehabilitation is recommended for patients with coronary heart disease and heart failure, but few studies have examined the benefits in AF. An observational study found that patients who gained cardiorespiratory fitness over a five-year follow-up were significantly less likely to have recurrences of AF.4 A randomised controlled trial showed that 12 weeks of aerobic interval training reduced the time spent in AF compared to usual care but the study enrolled just 51 patients and follow-up was only four weeks.5
The ACTIVE-AF trial assessed the impact of a six-month exercise programme combining supervised and home-based aerobic exercise on AF recurrence and symptom severity — during the intervention and after a further six months of follow-up. The study included patients with short AF episodes (paroxysmal AF) or longer episodes requiring intervention to restore normal rhythm (persistent AF). Patients whose normal heart rhythm cannot be restored (permanent AF) were excluded.
The trial randomly allocated 120 patients with symptomatic AF to an exercise intervention or usual care for six months. The intervention included supervised exercise (weekly for three months then fortnightly for three months) and an individualised weekly plan to follow at home. Over the six months the target was to increase aerobic exercise up to 3.5 hours per week. Supervised sessions were typically higher intensity to raise cardiorespiratory fitness, while home-based exercise was typically a moderate intensity aerobic activity of the patient’s choice (e.g. walking, indoor cycling, swimming). The usual care group received exercise advice but no active intervention. All patients received usual medical care from their cardiologist who was blinded to study group allocation.

Mosquitoes spread viruses that cause potentially deadly diseases such as Zika, dengue fever and yellow fever. New U.S. Army-funded research uses gene editing to render certain male mosquitoes infertile and slow the spread of these diseases.
Researchers at the Army’s Institute for Collaborative Biotechnologies and the University of California Santa Barbara used a gene editing tool known as CRISPR-Cas9 to target a specific gene tied to fertility in male mosquitoes. CRISPR-Cas9 is a genome editing tool that is creating a buzz in the science world, according to yourgenome.org. It is “faster, cheaper and more accurate than previous techniques of editing DNA and has a wide range of potential applications.”
Researchers experimented with the Aedes aegypti mosquitoes, which are found in tropical, subtropical and temperate regions throughout the world. The study, published in the Proceedings of the National Academy of Sciences, discerned how a mutation can suppress the fertility of female mosquitoes.
“This is yet one more important and exciting example of how synthetic biology tools are demonstrating unparalleled utility,” said Dr. James Burgess, ICB program manager for the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory. “In this case, it’s a precision increase from chainsaw to a scalpel leading to the correct biochemical outcome that could substantially reduce the population of a very infectious mosquito.”
To manage populations, scientists use a vector-control practice called the sterile insect technique in which they raise a lot of sterile male insects and they then release these males in numbers that overwhelm their wild counterparts. Females that mate with sterile males before finding a fertile one are themselves rendered infertile, thereby decreasing the size of the next generation.
Repeating this technique several times has the potential to crash the population because each generation is smaller than the last; releasing a similar number of sterile males has a stronger effect over time.

Feeling like leisure is wasteful and unproductive may lead to less happiness and higher levels of stress and depression, new research suggests.
In a series of studies, researchers examined the effects of a common belief in modern society: that productivity is the ultimate goal and time’s a-wasting if you’re just having fun.
People who most strongly agreed with this belief not only enjoyed leisure less, but also reported poorer mental health outcomes, said Selin Malkoc, co-author of the study and associate professor of marketing at Ohio State University’s Fisher College of Business.
“There is plenty of research which suggests that leisure has mental health benefits and that it can make us more productive and less stressed,” Malkoc said.
“But we find that if people start to believe that leisure is wasteful, they may end up being more depressed and more stressed.”
One bright side: Some skeptical people could enjoy fun activities if leisure was part of a larger goal, and not an end in itself.

Exposure to wildfire smoke during pregnancy increases the risk that a baby will be born too early, a new Stanford University study suggests.
The study, published Aug. 14 in Environmental Research, finds there may have been as many as 7,000 extra preterm births in California attributable to wildfire smoke exposure between 2007 and 2012. These births occurred before 37 weeks of pregnancy when incomplete development heightens risk of various neurodevelopmental, gastrointestinal and respiratory complications, and even death.
Wildfire smoke contains high levels of the smallest and deadliest type of particle pollution, known as PM 2.5. These specks of toxic soot, or particulate matter, are so fine they can embed deep in the lungs and pass into the bloodstream, just like the oxygen molecules we need to survive.
The research comes as massive wildfires are again blazing through parched landscapes in the western U.S. — just a year after a historic wildfire season torched more than 4 million acres of California and produced some of the worst daily air pollution ever recorded in the state. During the 2020 fire season, more than half of the state’s population experienced a month of wildfire smoke levels in the range of unhealthy to hazardous.
This year could be worse, said Stanford environmental economist Marshall Burke, a co-author of the new study. And yet much remains unknown about the health impacts of these noxious plumes, which contribute a growing portion of fine particle pollution nationwide and have a different chemical makeup from other ambient sources of PM 2.5, such as agriculture, tailpipe emissions and industry.
One possible explanation for the link between wildfire smoke exposure and preterm birth, the authors say, is that the pollution may trigger an inflammatory response, which then sets delivery in motion. The increase in risk is relatively small in the context of all the factors that contribute to the birth of a healthy, full-term baby. “However, against a backdrop where we know so little about why some women deliver too soon, prematurely, and why others do not, finding clues like the one here helps us start piecing the bigger puzzle together,” said co-author Gary Shaw, DrPH, a professor of pediatrics and co-primary investigator of Stanford’s March of Dimes Prematurity Research Center.

Drinking alcohol during adolescence to young adulthood is associated with accelerated arterial stiffening, a precursor to cardiovascular disease. That’s the finding of a study presented at ESC Congress 2021.1
“There was some evidence of a graded increase with heavier usage, meaning that the more you drink, the greater the increase in arterial stiffness,” said study author Mr. Hugo Walford, a medical student at University College London, UK. “The relationship was not explained by other predisposing factors for heart disease, suggesting that risky behaviour during this period has a direct effect on vascular health.”
As people get older, their arteries naturally become stiffer and less elastic. Stiffer arteries are associated with higher risks of heart disease and stroke.2 Certain behaviours can accelerate arterial stiffening. For example, previous research has shown that smoking tobacco and drinking alcohol are linked with stiffer arteries in teenagers.3
As young adulthood is a critical period for initiation and heavy usage of smoking and alcohol, this study focused on changes in arterial stiffness between the ages of 17 and 24 and the relationship with these habits.
The study included 1,655 participants of the Avon Longitudinal Study of Parents And Children (ALSPAC) aged 17 to 24 years. Alcohol and smoking were measured at ages 17 and 24 and results at the two time points were combined. Alcohol use was classified as never, medium (4 drinks or less on a typical day of drinking), and high (more than 5 drinks on a typical drinking day). Smoking was categorised as never, past, medium (less than 10 cigarettes a day), and high (10 or more cigarettes daily).
Arterial stiffness was assessed at ages 17 and 24 using a non-invasive technique called carotid-femoral pulse wave velocity, which is a robust and independent predictor of future cardiovascular disease, especially in young people.4
The researchers examined associations between smoking and drinking habits and changes in arterial stiffness between ages 17 and 24. The analyses were adjusted for age, sex, and socioeconomic status, plus the following measures at age 24: body mass index, blood pressure, low-density lipoprotein (LDL) cholesterol, blood glucose, and C-reactive protein (a measure of inflammation).