Culture

Smoking increases both men's and women's risk of a major heart attack at all ages, but women smokers have a significantly higher increased risk compared to men, especially women under 50 years old, according to a study in the Journal of the American College of Cardiology. Despite the increased risk, smokers can reduce their risk to that of a never smoker in as little as a month after quitting.

Heart disease is the No. 1 cause of death for women and men worldwide, and acute ST segment elevation myocardial infarction (STEMI) is among the most life-threatening forms of heart disease. STEMI is sometimes called a major heart attack and is caused by a complete blockage of one of the main coronary arteries.

Smoking is a risk factor for heart disease and researchers have previously identified smoking as the cause of STEMI in nearly 50 percent of all cases. However, none have quantified and compared the incidence of STEMI associated with smoking between genders and within different age groups.

In research led by Sheffield Teaching Hospitals NHS Foundation Trust in partnership with the University of Sheffield, the authors sought to assess smoking as an independent risk factor for STEMI and determine the differences in risk between age groups and genders. They used a retrospective ecological cohort study to compile data for all patients in the South Yorkshire region of the U.K. who presented with acute STEMI between January 2009 and July 2014, which included 3,343 STEMIs. The percentage who were current smokers was similar between genders, with 46.8 percent of female patients and 47.6 percent of male patients.

They found that smoking increases STEMI risk in all patients, regardless of age or gender; however, the risk is higher in females compared to males at all ages. The largest relative risk difference between men and women smokers was in the 50-64 years old group, but the highest risk increase in both genders was in the 18-49 years group--the youngest group. Female smokers in this age group had a greater than 13 times higher risk of STEMI compared to their non-smoking female contemporaries. Young male smokers had an 8.6 times increased risk.

The authors of the study proposed several possible reasons why smoking leads to such a greater risk of STEMI for females, including that smoking may lower levels of serum estrogen. Estrogens, which have long been known to have protective effects against atherosclerosis, which is a buildup of fats, cholesterol and other substances within artery walls that can restrict blood flow, are inhibited in female smokers. Also, men have been found to have larger coronary arteries than women, meaning that chronic inflammation from smoking may lead to a greater degree of arterial narrowing in women than men since their arteries are narrower to begin with. Several other vascular conditions are more prevalent in female STEMI patients, including vasospasm, vasculitis and spontaneous coronary artery dissection. The researchers said it is highly likely that smoking perpetuates some of these events and imposes a greater increase in STEMI risk for women.

However, researchers also found it is possible to substantially reverse the risk by quitting smoking.

"Our study found that smoking cessation, regardless of age or gender, reduces STEMI risk to that of a never smoker, possibly within a month," said Ever Grech, MD, senior author of the study and consultant interventional cardiologist and TAVI lead at South Yorkshire Cardiothoracic Centre in Sheffield, U.K. "Patients who smoke merit encouragement to give up their habit, and this study adds quantitative evidence to the massive benefits of doing so."

Researchers also speculated that since a previous study had shown that physicians perceived coronary artery disease in males as being more important than in females, professional advice on smoking cessation may differ between genders if smoking is considered to be less of a cardiac risk for females.

The study had several limitations, including that it did not provide information about intensity of smoking or duration of smoking cessation in ex-smokers who were defined as being abstinent for at least one month. It also only included patients presenting with STEMI as a candidate for PCI and did not include those who died in the community prior to admission.

Microdata from Swedish population registers provide new insights into cities' economic growth paths. The data reveal a surge in regional inequality, with more and more resources flowing to cities atop the urban hierarchy, which thus acquire an increasing share of national wealth.

A particular viewpoint has come to dominate the science of cities. Cities of different sizes are seen as scaled copies of one another, expected to go through similar lifecycles of socioeconomic growth - only in different historical epochs. In this perspective, cities follow parallel growth trajectories and, as an urban system grows in wealth and people, the relative inequality between cities remains stable.

"This idea has always puzzled me. It does not correspond to the increasing regional inequalities we observe in many countries around the world. The notion that cities grow completely in parallel appears empirically ill-founded as it is derived from datasets that only cover larger metropolitan areas. It misses out on small towns, many of which face a struggling economy and sustained out-migration of young and educated individuals", says Dr Marc Keuschnigg who is an Associate Professor at Linkoping University's Institute for Analytical Sociology.

The escalating urban-rural divide stands against the established interpretation of "urban scaling," as the dominant framework is known among academics. In his research article "Scaling trajectories of cities", published in the Proceedings of the National Academy of Sciences (PNAS), Keuschnigg puts the idea of self-similar urban growth to the test.

The new study also uses data on smaller cities, gathered from Swedish population registers that capture, for the first time, the city growth trajectories of an entire urban system - from the smallest town with 2,600 inhabitants to the capital city with 2.5 million inhabitants.

The results demonstrate that regional inequalities between smaller and larger cities increased substantially during 1990-2012, the period of observation. While big cities' economic growth trajectories are extremely robust over time, places with less than 75,000 inhabitants show little resilience to economic shocks and structural changes in society. The data reveal a firm grip of an urban hierarchy on cities' economic growth: Dominant positions in the urban system give an advantage to larger cities, helping their economies to thrive on specialized service industries and the sustained in-migration of talent from their hinterlands.

Because cities that rank lower in the urban hierarchy lack such relative advantages, path dependencies place bounds on the self-similarity of urban growth and, in relative terms, the pace of life in today's regional centers will never compare to a nation's core metropolitan areas back in time when they were of similar size.

These findings draw attention to the increasingly uneven economic geography observed in many countries, with growing levels of inequality between urban and rural areas.

"My research is of considerable policy relevance. It empirically identifies regional divides and measures the social inequalities associated with city growth and regional migration", says Dr Marc Keuschnigg.

Each year during the holiday season, soup kitchens and charities alike are flooded with offers to volunteer. But is a donation of your time most beneficial to the charity, or would a financial contribution provide more value?

Researchers from Portland State University and Texas A&M University wondered what drives volunteering -- especially when a monetary donation would have more impact. Their study, "Why Do People Volunteer? An Experimental Analysis of Preferences for Time Donations," was published in this spring in the journal Management Science.

PSU Assistant Professor of Economics J. Forrest Williams worked with Texas A&M economics professors Alexander Brown and Jonathan Meer to consider what drives volunteers. They found time and time again, people preferred to donate their time even when doing so is less efficient

Why do people make that choice? Williams said the "warm glow" effect appears to be responsible. Warm glow is described simply as the positive feeling associated with volunteering or donating to charity.

"If you have really high wages, why would you give up a few hundred dollars an hour, when you could just work an hour and donate that amount and then provide significantly more value than your time would be worth to the charity?" Williams said.

Past research assumes, he added, that when given the choice between donating $10 worth of someone's time and $10, the options are equivalent. Their research proves otherwise.

"The warm glow you get from volunteering appears to be significantly higher than that of giving money. And that went against what a lot of the field believed," Williams said.

Their findings should inform future economic studies and conversations considering gifts of time and money, he added.

"If we are only concerned about the impact of our donations, it makes no economic sense," Williams said of people's preferences to donate time. The warm glow effect is just that persuasive.

The study controlled for a variety of factors that may influence someone's choices: recognition, networking, reciprocity, happiness gained from working with others, etc.

Participants still chose to donate their time even when their choice essentially lost money for the charity and there was no personal benefit.

"If you make $100 an hour, then you go work in a soup kitchen and don't provide $100 worth of service in an hour, they would be better off if you just gave them $100," he said.

It's unclear how charities should respond to this finding. It's conceivable they could be better off insisting on donations and paying for labor to replace volunteers. But they may also lose a lot of potential donors who gain greater benefit from the volunteering experience. Those donors might end up volunteering at a competing charity. Further, volunteers might increase the visibility of the charity increasing future monetary donations, something this study could not address.

"Even if you are hyper-effective at what you do, it's just so unlikely that the value of your time there is greater than the value of the money you would give," Williams said.

Research presented at the Society of Nuclear Medicine and Molecular Imaging's 2019 Annual Meeting draws a strong link between severe obstructive sleep apnea (OSA) and impaired coronary flow reserve, which is an early sign of the heart disease atherosclerosis. Using 13N-ammonia positron emission tomography/computed tomography (PET/CT), researchers were able to noninvasively evaluate coronary microvascular function in OSA patients and use their findings to predict cardiovascular disease risk.

Obstructive sleep apnea occurs when a person's airway is blocked while sleeping, which causes intermittent pauses in breathing. According to the American Sleep Apnea Association, an estimated 22 million Americans suffer from sleep apnea, which is increasingly recognized as a cardiovascular disease risk factor. Left untreated, OSA can lead to high blood pressure, stroke, chronic heart failure and other cardiovascular problems.

To evaluate the cardiovascular disease risk factors in OSA patients, researchers conducted 13N-ammonia PET/CT imaging on 38 patients, who were divided into three groups based on the severity of their sleep apnea. During the PET/CT imaging, myocardial blood flow and coronary flow reserve--key indicators of coronary dysfunction--were automatically calculated using quantitative PET/CT software.

The mean rest myocardial blood flow was similar among patients in the three groups of mild, moderate and severe OSA. The mean hyperemic myocardial blood flow was also similar, though researchers found that the blood flow decreased gradually as the severity of OSA increased. There were, however, significant differences in the mean coronary flow reserve among the three groups--those with severe OSA had a substantially lower coronary flow reserve.

"As we all know, impaired coronary flow reserve is an early sign of atherosclerosis," said Ruonan Wang, MD, The First Hospital of Shanxi Medical University in Taiyuan, China. "Our study suggests that patients with OSA, especially severe OSA, should receive PET myocardial perfusion imaging as early as possible to exclude coronary microcirculatory dysfunction."

(Boston)--A new study raises the possibility that close-range blast exposure among veterans with a genetically higher risk for Alzheimer's disease (AD), may make them more susceptible to degradation of their white matter, the part of the brain made of fiber connections called axons that connect nerve cells.

Although there is evidence that genetic risk for AD may elevate the risk of neurodegeneration following traumatic brain injury, it has been unknown if blast exposure also interacts with AD disease risk to promote neurodegeneration.

Researchers examined whether apolipoprotein (APOE) ε4, a well-known genetic risk factor for AD, influenced the relationship between close-range blast exposure (approximately 10 yards) and white matter integrity in a group of 200 Iraq and Afghanistan War veterans.

"We found that veterans who had close-range blast exposure and carried the ε4 allele had more spatially diffused white matter abnormalities than those without the ε4 allele," explained corresponding author Danielle R. Sullivan, PhD, a research health science specialist at the National Center for PTSD, VA Boston Healthcare System and assistant professor of psychiatry at Boston University School of Medicine. According to Sullivan this interaction remained significant after controlling for traumatic brain injury, pointing to the specificity of close-range blast exposure and APOE in white matter disruptions.

The researchers believe this study has implications for the long-term health effects of veterans returning from the Iraq and Afghanistan Wars. "It suggests that veterans who experienced a blast exposure within close-range and have elevated genetic risk for neurodegenerative disease may be at a greater risk for neurodegeneration and subsequent presentation of neurodegenerative diseases such as Alzheimer's disease."

Research has shown that repetitive and sub-concussive injuries without apparent acute symptoms are especially important in neurodegenerative processes. "Therefore, it is possible that close-range blast exposure, particularly when combined with genetic risk for neurodegenerative disease, may be a sensitive marker for sub-clinical but persistent effects on the brain related to potential neurodegenerative processes."

PHILADELPHIA (June 24, 2019) - New research from the Monell Center analyzed nearly 400,000 food reviews posted by Amazon customers to gain real-world insight into the food choices that people make. The findings reveal that many people find the foods in today's marketplace to be too sweet.

"This is the first study of this scale to study food choice beyond the artificial constraints of the laboratory," said study lead author Danielle Reed, PhD, a behavioral geneticist at Monell. "Sweet was the most frequently mentioned taste quality and the reviewers definitively told us that human food is over-sweetened."

The study used data posted on an open-source data science site to examine 393,568 unique food reviews of 67,553 products posted by 256,043 Amazon customers over a 10-year period. Using a sophisticated statistical modeling program to identify words related to taste, texture, odor, spiciness, cost, health, and customer service, the scientists computed the number of reviews that mentioned each of these categories.

"Reading and synthesizing almost 400,000 reviews would essentially be impossible for a human team, but recent developments in machine learning gave us the ability to understand both which words are present and also their underlying semantic meaning," said study coauthor Joel Mainland, PhD, an olfactory neurobiologist at Monell.

The focus on product over-sweetness was striking, as almost one percent of product reviews, regardless of food type, used the phrase "too sweet." When looking at reviews that referred to sweet taste, the researchers found that over-sweetness was mentioned 25 times more than under-sweetness.

The findings, published online in advance of print in Physiology & Behavior, indicated that over 30 percent of the Amazon food product reviews mentioned "taste," making it the most frequently-used word.

Drilling down, the scientists found that sweet taste was mentioned in 11 percent of product reviews, almost three times more often than bitter. Saltiness was rarely mentioned, a somewhat surprising finding in light of public health concerns about excess salt consumption.

Seeking to better understand individual differences in how people respond to a given food, the scientists also looked at responses to the 10 products that received the widest range of ratings, as defined by the variability in the number of stars the product received. They identified two factors that tended to account for polarizing reviews related to a product: product reformulation and differing perspectives on the product's taste. With regard to taste, people often rated the sweetness of a product differently. Response to a product's smell also contributed to differences in opinion about a particular product.

"Genetic differences in taste or olfactory receptor sensitivity may help account for the extreme reactions that some products get," said Reed. "Looking at the responses to polarizing foods could be a way to increase understanding of the biology of personal differences in food choice."

Together, the findings illustrate the potential uses of big-data approaches and consumer reviews to advance sensory nutrition, an emerging field that integrates knowledge from sensory science with nutrition and dietetics to improve health. Moving forward, similar methods may inform approaches to personalized nutrition that can match a person's sensory responses to inform healthier food choices.

Told to optimize for speed while racing down a track in a computer game, a car pushes the pedal to the metal ... and proceeds to spin in a tight little circle. Nothing in the instructions told the car to drive straight, and so it improvised.

This example - funny in a computer game but not so much in life - is among those that motivated Stanford University researchers to build a better way to set goals for autonomous systems.

Dorsa Sadigh, assistant professor of computer science and of electrical engineering, and her lab have combined two different ways of setting goals for robots into a single process, which performed better than either of its parts alone in both simulations and real-world experiments. The researchers presented the work June 24 at the Robotics: Science and Systems conference.

"In the future, I fully expect there to be more autonomous systems in the world and they are going to need some concept of what is good and what is bad," said Andy Palan, graduate student in computer science and co-lead author of the paper. "It's crucial, if we want to deploy these autonomous systems in the future, that we get that right."

The team's new system for providing instruction to robots - known as reward functions - combines demonstrations, in which humans show the robot what to do, and user preference surveys, in which people answer questions about how they want the robot to behave.

"Demonstrations are informative but they can be noisy. On the other hand, preferences provide, at most, one bit of information, but are way more accurate," said Sadigh. "Our goal is to get the best of both worlds, and combine data coming from both of these sources more intelligently to better learn about humans' preferred reward function."

Demonstrations and surveys

In previous work, Sadigh had focused on preference surveys alone. These ask people to compare scenarios, such as two trajectories for an autonomous car. This method is efficient, but could take as much as three minutes to generate the next question, which is still slow for creating instructions for complex systems like a car.

To speed that up, the group later developed a way of producing multiple questions at once, which could be answered in quick succession by one person or distributed among several people. This update sped the process 15 to 50 times compared to producing questions one-by-one.

The new combination system begins with a person demonstrating a behavior to the robot. That can give autonomous robots a lot of information, but the robot often struggles to determine what parts of the demonstration are important. People also don't always want a robot to behave just like the human that trained it.

"We can't always give demonstrations, and even when we can, we often can't rely on the information people give," said Erdem Biyik, a graduate student in electrical engineering who led the work developing the multiple-question surveys. "For example, previous studies have shown people want autonomous cars to drive less aggressively than they do themselves."

That's where the surveys come in, giving the robot a way of asking, for example, whether the user prefers it move its arm low to the ground or up toward the ceiling. For this study, the group used the slower single question method, but they plan to integrate multiple-question surveys in later work.

In tests, the team found that combining demonstrations and surveys was faster than just specifying preferences and, when compared with demonstrations alone, about 80 percent of people preferred how the robot behaved when trained with the combined system.

"This is a step in better understanding what people want or expect from a robot," said Sadigh. "Our work is making it easier and more efficient for humans to interact and teach robots, and I am excited about taking this work further, particularly in studying how robots and humans might learn from each other."

Better, faster, smarter

People who used the combined method reported difficulty understanding what the system was getting at with some of its questions, which sometimes asked them to select between two scenarios that seemed the same or seemed irrelevant to the task - a common problem in preference-based learning. The researchers are hoping to address this shortcoming with easier surveys that also work more quickly.

"Looking to the future, it's not 100 percent obvious to me what the right way to make reward functions is, but realistically you're going to have some sort of combination that can address complex situations with human input," said Palan. "Being able to design reward functions for autonomous systems is a big, important problem that hasn't received quite the attention in academia as it deserves."

The team is also interested in a variation on their system, which would allow people to simultaneously create reward functions for different scenarios. For example, a person may want their car to drive more conservatively in slow traffic and more aggressively when traffic is light.

The latest supplement to the American Ornithological Society's checklist of North and Middle American birds is being published in The Auk: Ornithological Advances, and it includes several major updates to the organization of the continent's bird species. The official authority on the names and classification of the region's birds, the checklist is consulted by birdwatchers and professional scientists alike and has been published since 1886.

Birdwatchers eager to build their "life lists" will be especially interested in the five species added to the checklist due to "splits," where scientists have determined that bird populations once believed to be part of the same species are actually distinct; these newly-recognized species include the Choco Screech-Owl, Socorro Parakeet, and Stejneger's Scoter. Eight species from Eurasia and South America have also been added to the list as a result of recent sightings in North America, and one species familiar to parrot fanciers, the Budgerigar, was removed from the list. Native to Australia, escaped pet "budgies" established a wild breeding population in central Florida in the 1950s. However, the population had been declining for decades, and as of 2014, Florida's budgies have died out, possibly due to competition for nest sites from other non-native birds.

More than just a list that species are added to and deleted from, however, the checklist is also the authority on how North America's bird species are sorted into genera and families based on their evolutionary relationships. This year, new genetic data led to the rearrangement of several of these groups. A genus of Neotropical tanagers called Tangara was split up, and a group of seabirds known as storm-petrels that were previously classified into two genera have now been lumped into a single genus called Hydrobates. AOS's North American Classification Committee, the group of scientists responsible for the checklist, also made several tweaks to the names and classifications of hummingbird species, including taking the step of changing the official English name of one species that occurs in the southwestern U.S. and Mexico from "Blue-throated Hummingbird" to "Blue-throated Mountain-gem."

"There are seven hummingbird species in the genus Lampornis, and all but two of them already had the common name 'mountain-gem,'" explains committee chair Terry Chesser, USGS Research Zoologist at the Patuxent Wildlife Research Center. "Usually we don't like to change the English names just to make them 'better,' because you could go through and make practically any bird name better if you wanted to, but in this case we thought it was worthwhile. We hope that calling all the birds in that genus by the name 'mountain-gem' will help birders understand a little bit more about the birds they're looking at, both in terms of associating these seven species with each other and in recognizing them as distinct from species in other genera simply called 'hummingbird.'"

Nuclear magnetic resonance spectroscopy - NMR spectroscopy for short - is one of the most important methods of physicochemical analysis. It can be used to precisely determine molecular structures and dynamics. The importance of this method is also evidenced by the recognition of ETH Zurich's two latest Nobel laureates, Richard Ernst and Kurt Wüthrich, for their contributions to refining the method.

The technique is based on nuclear magnetic resonance, which takes advantage of the fact that certain atomic nuclei interact with a magnetic field. A key factor here is the nuclear spin, which can be compared with the spinning of a child's top. Similar to a top that begins to wobble - experts call this precession - nuclear spins that are exposed to a magnetic field begin to precess. This generates an electromagnetic signal that can be measured using an induction coil.

Higher resolution

A team of researchers led by Christian Degen, Professor of Solid-State Physics at ETH Zurich, has developed a new approach, making it possible to directly track the precession of single nuclear spins. In comparison: conventional NMR measurements usually require at least 1012 to 1018 atomic nuclei in order to register a measurement signal.

In their project, the ETH researchers analysed the behaviour of carbon-13 atoms in diamonds. Rather than using conventional methods to measure the precession of the carbon nucleus, they used the spin of an adjacent electron in an N-V centre - an imperfection in the diamond's crystal lattice - as a sensor. Kristian Cujia, a doctoral student in Degen's group, summarises the principle thus: "We use a second quantum system to study the behaviour of the first quantum system. In this way, we created a very sensitive way of measurement."

Potential for future applications

Quantum systems are hard to pin down, as any measurement will also influence the system being observed. Therefore, the researchers were unable to track the precession continuously; its movement would have been changed too drastically. To solve this problem, they developed a special measurement method to capture the spin of the carbon atom through a series of weak measurements in quick succession. As a result, they were able to keep the influence of their observation so small as to not influence the system measurably, leaving the original circular motion perceptible.

"Our method paves the way for remarkable advances in NMR technology," Degen explains. "This potentially enables us to directly record the spectra of individual molecules and analyse structures at the atomic level." As a first example, the physicists identified the three-dimensional position of the carbon nuclei in the diamond lattice with atomic resolution. The physicists see huge potential in this development. Such detailed NMR measurements could lead to completely new insights in many areas, as has already been the case with conventional NMR spectroscopy in recent decades."

The study, carried out by experts from the University of Nottingham and funded by the NIHR School for Primary Care Research, found that there was nearly a 50% increased risk of dementia among patients aged 55 and over who had used strong anticholinergic medication daily for three years or more.

Anticholinergic drugs help to contract and relax muscles. They work by blocking acetylcholine, a chemical that transmits messages in the nervous system.

Doctors prescribe the drugs to treat a variety of conditions, including chronic obstructive pulmonary disease, bladder conditions, allergies, gastrointestinal disorders and symptoms of Parkinson's disease.

These medicines can have short-term side effects, including confusion and memory loss, but it is less certain whether long-term use increases the risk of dementia.

The research, published in the JAMA Internal Medicine journal and led by Professor Carol Coupland from the University's Division of Primary Care, looked at the medical records of 58,769 patients with a diagnosis of dementia and 225,574 patients without a diagnosis of dementia, all aged 55 and over and registered with UK GPs contributing data to the QResearch database, between 1 January 2004 and 31 January 2016.

The study findings showed increased risks of dementia for anticholinergic drugs overall and specifically for the anticholinergic antidepressants, antipsychotic drugs, antiparkinsons drugs, bladder drugs and epilepsy drugs after accounting for other risk factors for dementia.

No increased risks were found for the other types of anticholinergic drug studied such as antihistamines and gastrointestinal drugs.

Professor Tom Dening, Head of the Centre for Dementia at the University of Nottingham and a member of the research study team, said: "This study provides further evidence that doctors should be careful when prescribing certain drugs that have anticholinergic properties. However, it's important that patients taking medications of this kind don't just stop them abruptly as this may be much more harmful. If patients have concerns, then they should discuss them with their doctor to consider the pros and cons of the treatment they are receiving."

The 58,769 patients with dementia had an average age of 82 and 63% were women. Each dementia case was matched to five control patients of the same age, sex, and general practice.

Anticholinergic drug exposure was assessed using prescription information over a complete period of 10 years from 1 to 11 years before diagnosis of dementia or the equivalent dates in control patients, and was compared between the two patient groups. Further analysis looked at prescriptions for anticholinergic drugs up to 20 years before diagnosis of dementia.

This is an observational study so no firm conclusions can be drawn about whether these anticholinergic drugs cause dementia, and it is possible that the drugs were being prescribed for very early symptoms of dementia.

Professor Coupland said: "Our study adds further evidence of the potential risks associated with strong anticholinergic drugs, particularly antidepressants, bladder antimuscarinic drugs, anti-Parkinson drugs and epilepsy drugs.

"The risks of this type of medication should be carefully considered by healthcare professionals alongside the benefits when the drugs are prescribed and alternative treatments should be considered where possible, such as other types of antidepressants or alternative types of treatment for bladder conditions. These findings also highlight the importance of carrying out regular medication reviews.

"We found a greater risk for people diagnosed with dementia before the age of 80 which indicates that anticholinergic drugs should be prescribed with caution in middle-aged people as well as in older people."

These results, along with those of a similar study published in 2018 help to clarify which types of anticholinergic drug are associated with the highest risks of dementia.

In the 1-11 years before the dementia diagnosis date or equivalent in controls, nearly 57% of cases and 51% of controls were prescribed at least one strong anticholinergic drug, with an average of six prescriptions in cases and 4 in controls. The most frequently-prescribed types of drugs were antidepressants, anti-vertigo and bladder antimuscarinic drugs - which are used to treat an overactive bladder.

The increased risk associated with these drugs indicates that if the association is causal around 10% of dementia diagnoses could be attributable to anticholinergic drug exposure, which would equate to around 20,000 of the 209,600 new cases of dementia per year in the UK.

This is a sizeable proportion and is comparable with other modifiable risk factors for dementia, including 5% for midlife hypertension, 3% for diabetes, 14% for later life smoking and 6.5% for physical inactivity.

Serotonin is a multipurpose molecule found throughout the brain, playing a role in memory, cognition, and feelings of happiness and other emotions. In particular, researchers have long debated serotonin's role in sleep: Does serotonin promote sleep, or its opposite, wakefulness?

Now, Caltech scientists have found that serotonin is necessary for sleep in zebrafish and mouse models.

A paper describing the research appears online on June 24 in the journal Neuron. The work is a collaboration between the Caltech laboratories of David Prober, professor of biology and affiliated faculty member of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech; and Viviana Gradinaru (BS '05), professor of neuroscience and biological engineering, Heritage Medical Research Institute Investigator, and director of the Chen Institute's Center for Molecular and Cellular Neuroscience.

Previous studies on serotonin and sleep have yielded conflicting results. Some research showed that serotonin promotes sleep, but other work showed that serotonin-producing neurons were most active and releasing the chemical during wakefulness.

In order to settle this debate, the Caltech team focused on a region called the raphe nuclei, which has the brain's main population of serotonin-producing (or serotonergic) neurons. The raphe are evolutionarily ancient structures found in the brain stem of a wide range of organisms from fish to humans, and they are responsible for both manufacturing and sending out serotonin to other brain regions.

Led by senior postdoctoral scholar Grigorios Oikonomou of the Prober lab, the research began using zebrafish, tiny transparent fish that are widely used as a model to study sleep. Like humans, zebrafish larvae are diurnal--meaning that their sleep occurs mostly at night.

First, the researchers genetically mutated zebrafish so that their raphe did not produce serotonin. These mutant fish, the team found, slept about half as much as normal fish. In another experiment, the researchers removed the raphe altogether, and these fish also slept much less than usual.

"This suggests that serotonin produced by the raphe is required for the fish to get normal amounts of sleep," says Oikonomou.

In a third set of experiments, zebrafish were genetically modified so that their raphe could be activated by light. Shining a light on these fish put them to sleep, implying that activation of the raphe induces sleep. This effect requires serotonin, because activating the raphe in fish that do not synthesize serotonin had no effect on sleep.

The team from the Prober laboratory then collaborated with scientists in the Gradinaru laboratory to continue the serotonin studies in mice. Led by graduate student Michael Altermatt, the team examined serotonergic neurons in the mouse raphe and confirmed that they are indeed mostly active while the animals are awake and less active during sleep, in agreement with previous studies.

As Prober's lab did in zebrafish, the Gradinaru lab's team genetically removed the serotonergic neurons in the mouse raphe and found that the mice slept less than usual. Stimulating these neurons with light also put the mice to sleep but only when the light was administered at frequencies that are consistent with the naturally occurring baseline activity pattern of these neurons during wakefulness.

"There's an obvious paradox here: stimulating the neurons causes the animals to sleep, and yet the neurons are normally active during the day," says Altermatt.

Oikonomou explains: "There are two main factors that control sleep. One is the circadian clock--when it is light during the day, the body is awake, and when it gets dark, the body knows to sleep. The other factor is called homeostatic sleep pressure. When you wake up in the morning, you have just gotten rest, and so you're energetic. As the day goes on, you get tired and sleepy, so there is a building of pressure to sleep. If you don't sleep that night, your sleep pressure is even higher, and you are even more tired the next day even though it's light outside, and your circadian clock dictates that you should be awake."

"The theory is that, in order to sleep, you need to have high sleep pressure and the circadian clock needs to be aligned with the time of day--nighttime for diurnal creatures like us and daytime for nocturnal animals."

The researchers theorize that the firing of neurons in the raphe and their release of serotonin is a way for the brain to build up sleep pressure. Indeed, they found that zebrafish lacking serotonin as well as mice with ablated raphe show reduced sleep pressure.

While the studies were in animal models, the raphe region and its production of serotonin are similar in human brains. The research can contribute to explanations of some sleep-related side effects of common antidepressant drugs that increase serotonin levels in the brain.

Bottom Line: Having a family member who was previously dispensed prescription opioids was associated with higher odds of overdose for individuals who themselves didn't have an opioid prescription in this analysis of insurance company data. The study included 2,303 people with the earliest date of an opioid overdose in a family and 9,212 others in the insurance database for comparison. Researchers report the increased risk of opioid overdose for an individual if a family member was prescribed an opioid applied to all age groups and increased with greater quantities of opioids prescribed. Potential interventions include encouraging patients to properly dispose of or secure prescription opioids in their homes, as well as improving patient and public education. Limitations of the study include that the time period analyzed (through 2015) may not reflect current patterns of opioid prescribing or overdoses.

Authors: Joshua J. Gagne, Pharm.D., Sc.D., Brigham and Women's Hospital, Harvard Medical School, Boston, and coauthors

(doi:10.1001/jamainternmed.2019.1064)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

A new study has found that variability in night-to-night sleep time and reduced sleep quality adversely affect the ability of older adults to recall information about past events. The study also found unexpected racial differences in the type of sleep patterns tied to lower memory performance across both younger and older African American research participants.

Although further investigation will be needed to confirm the results of the pilot study, the findings could help open up a new area of research aimed at understanding the potential connection between poor sleep and the memory declines associated with aging. And the study, which included 50 Atlanta-area adults, also underscores the importance of sleep in maintaining good cognitive functioning.

"The night-to-night variability in the older study participants had a major impact on their performance in tests aimed at evaluating episodic memory," said Audrey Duarte, an associate professor in Georgia Tech's School of Psychology and principal investigator in the Memory and Aging Lab. "The association between sleep and memory has been known, but this study's novelty is showing that the connection is particularly evident for older adults and black participants, regardless of age."

The research, supported by a National Science Foundation Graduate Research Fellowship, was reported June 4 in the journal Frontiers in Human Neuroscience. It is believed to be the first study of the relationship between sleep and memory with both age and racial differences.

Duarte and Emily Hokett, a Ph.D. student in the School of Psychology, recruited 81 volunteers from the Atlanta area. The volunteers were evaluated carefully to screen out those who had mild cognitive impairment or other potentially confounding factors. Younger adults were recruited in the age range of 18 to 37 years, while older adults were recruited in the range from 56 to 76 years. Ultimately, 50 adults were selected for the study.

"We wanted to look at lifestyle factors to see how people sleep normally, and how their sleep patterns change over time," Hokett explained. "We wanted to know how sleep affected memory performance - how well they remembered things and how well their brains functioned depending on how well they slept."

The participants were given accelerometers worn on their wrists to measure sleep duration and quality over a period of seven nights. Though they did not measure brain waves, the devices allowed sleep measurements to be done in the participants' own homes. The researchers sought to provide a more realistic measurement than testing done in sleep labs, which typically lasts just one night.

Participants were asked to visit a Georgia Tech laboratory for a memory test that measured electroencephalography (EEG) brain wave activity as they attempted to recall word pairs that had been shown to them earlier. Not surprisingly, better performance correlated with better sleep in most of the older adults.

But Duarte and Hokett were surprised that the relationship between poor sleep and memory-related brain activity extended to both older and younger black participants - some of whom were college students. To understand the potential causes of the poor sleep, they administered a standardized questionnaire designed to measure stress levels in those participants.

"The main factor that correlated with poor sleep quality in black participants was race-related stress," said Hokett. "When participants had higher values on that measure of stress, they would also have greater sleep fragmentation, on average. We found a very significant relationship here."

The study found that black adults slept for 36 minutes less than other adults, which translated into a 12% decrease in memory-related brain activity. On an average night, black adults in the study spent 15 minutes more time awake after falling asleep than did other participants.

The study also found significant variation among subjects in each age group. "Some of our 70-year-old subjects looked like our 20-year-old students," Duarte said. "There are many factors that contribute to individual differences."

In future research, Duarte and Hokett hope to expand their study to a larger group of participants, to study the relationship between sleep and memory in other underrepresented minorities, and to explore whether variations in sleep patterns could predict a person's likelihood of experiencing diseases such as Alzheimer's.

The study's takeaway message may be that regular sleep is important at any age for the best cognitive performance.

"You can imagine that many people, students among them, may have variable sleep patterns based on staying up late to study and sleeping in on weekends to catch up," Duarte said. "This data shows that may not be the greatest strategy for optimizing memory ability."

Yet improvements in sleep may be one area where people concerned about cognitive impairment may have an opportunity to make improvements.

"In understanding normative aging, lifestyle factors are a good area to target because they are potentially factors we can control," said Duarte. "It's been known for decades that important things are happening while you sleep with regard to memory consolidation and strengthening of memories. Because we knew that sleep quality typically declines in normal aging, this was a prime target for study."

USC researchers have discovered a secret sauce in the brain's vascular system that preserves the neurons needed to keep dementia and other diseases at bay.

The finding, in a mouse model of the human brain, focuses on specific cells called pericytes and reveals that they play a previously unknown role in brain health. Pericytes secrete a substance that keeps neurons alive, even in the presence of leaky blood vessels that foul brain matter and result in cognitive decline.

The study, which appears today in Nature Neuroscience, helps explain the cascade of problems that lead to neurodegeneration after stroke or traumatic brain injury, as well as in diseases like Alzheimer's and Parkinson's -- and suggests a potential strategy for therapy.

"What this paper shows is if you lose these vascular cells, you start losing neurons. The link with neurodegeneration was really not that clear before," said senior author Berislav Zlokovic, director of the Zilkha Neurogenetic Institute at the Keck School of Medicine of USC.

The discovery comes at a time when scientists are beginning to understand Alzheimer's disease as the result of multiple processes that begin long before memory loss sets in. Many researchers are shifting their focus from the amyloid plaques that accumulate in the brain later in life toward other targets earlier in the timeline.

Zlokovic, for example, studies the layers of cells that make up blood vessels in the brain. His previous research shows that the more permeable, or leaky, a person's brain capillaries, the more cognitive disability they have.

For this new experiment in mice, Zlokovic zeroed in on pericytes in the brain's blood vessels. Pericytes help regulate blood flow and keep blood vessel walls sealed tight. When researchers artificially removed pericytes, they saw rapid degeneration of the blood-brain barrier, a slowdown of blood flow and the loss of brain cells.

To further understand the role of pericytes, the scientists infused mice with a protein, or growth factor, secreted by pericytes in the brain and not found elsewhere in the body. They found that, even with pericyte cells artificially removed, the growth factor protected neurons and the brain cells didn't die. The results persisted even with constricted blood flow.

Because these pericytes are implicated in many diseases -- including Huntington's, Parkinson's, stroke, brain trauma and amyotrophic lateral sclerosis -- the research offers intriguing possibilities for further investigation.

"This opens up an entirely new view of the possible pathogenesis of Alzheimer's disease," Zlokovic said.

Berkeley -- The rise of anti-immigration rhetoric and policies in the United States following the 2016 presidential election may be taking its toll on the health of California's Latinx youth, including those who are U.S. citizens, suggests a new study led by University of California, Berkeley, researchers.

The study tracked the mental and physical health of U.S.-born children of Mexican and Central American immigrants in California in the years before and after the 2016 election. It also asked about their sleep quality and their degree of worry about the personal consequences of U.S immigration policies.

Nearly half of the youth reported worrying at least sometimes about the impacts of U.S. immigration policy on their families. Those with more worries also experienced higher anxiety and poorer sleep quality than their peers.

When the researchers compared the youth's well-being before and after the election, they found that anxiety symptoms increased more markedly among individuals who reported more worry about immigration policies.

"We're seeing an increase in anxiety that is related to kids' concern about the personal consequences of U.S. immigration policy, and these are U.S.-born citizens," said Brenda Eskenazi, the Brian and Jennifer Maxwell Endowed Chair in Public Health in UC Berkeley's School of Public Health.

"Further, these are kids in California, a sanctuary state with more protective policies for immigrant families, compared to many other states," Eskenazi said. "So, this study is probably reflecting the best-case scenario of how children of immigrants in other states are being affected."

Eskenazi is the lead and corresponding author of a paper describing the results that appears June 24 in the Journal of the American Medical Association: Pediatrics.

The research drew upon mental and physical health data of 397 Latinx youth that was gathered by the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal study of Mexican farmworker families in California. Each participant in the study had at least one parent who was an immigrant; the documentation status of the parents was unknown.

Researchers assessed teens' blood pressure, body mass, anxiety and depression symptoms and overall health at the age of 14, before the 2016 presidential election, and again at the age of 16, during the year after the election.

At their evaluations at age 16, teens also completed the Pittsburgh Sleep Quality Index, which assessed their sleep quality, and the Perceived Immigration Policy Effects Scale (PIPES), which gauged their levels of concern about the effects of U.S. immigration policies on their families.

Between 41% and 45% of the teens reported on the PIPES survey that they worried at least sometimes "about the impact of immigration policies on the family," "about family separation due to deportation" or "that a family member would be reported to immigration officials." Teens with those concerns experienced higher anxiety levels and worse sleep than the others.

"These results are problematic, because high levels of anxiety are not necessarily fleeting," said Nancy Gonzales, dean of natural sciences at Arizona State University and co-author on the paper. "They can impact other aspects of children's well-being including their ability to stay focused in school, and if they are living with prolonged anxiety, that also has long-term effects on their physical health and susceptibility to problems like alcohol and substance abuse."

Co-author Julianna Deardorff, an associate professor in the Maternal and Child Health Program in UC Berkeley's School of Public Health, noted that the higher levels of anxiety faced by these teens is likely piled on top of other challenges and responsibilities that come with living with immigrant parents, including being an English translator for Spanish-speaking family members and helping relatives navigate U.S. services and institutions. The fear of having a family member reported may also keep them from seeking treatment, Deardorff added.

"It's not just that these youth are faced with the prospect of ICE coming to their door and taking away their parents, but in addition to that, they are having to navigate through settings that may not feel friendly in this political climate, in order to help themselves and their parents," Deardorff said.

The team is currently following up with the teens at age 18 to see if the increase in anxiety observed the year following the election has continued. It also is assessing the teens' academic performance and whether they are engaging in high-risk behaviors.