Culture

People at high genetic risk of stroke can still reduce their chance of having a stroke by sticking to a healthy lifestyle, in particular stopping smoking and not being overweight, finds a study in The BMJ today.

These findings "highlight the potential of lifestyle measures to reduce risk of stroke across entire populations, even in those at high genetic risk of stroke," say the researchers.

Stroke is a complex disease caused by both genetic and environmental factors, including diet and lifestyle. But could adhering to a healthy lifestyle offset the effect of genetics on stroke risk?

A team of international researchers decided to find out by investigating whether a genetic risk score for stroke is associated with actual ("incident") stroke in a large population of British adults.

They developed a genetic risk score, based on 90 gene variants known to be associated with stroke from 306,473 white men and women in the UK Biobank - a database of biological information from half a million British adults.

Participants were aged between 40 and 73 years and had no history of stroke or heart attack. Adherence to a healthy lifestyle was based on four factors: non-smoker, diet rich in fruit, vegetables and fish, not overweight or obese (body mass index less than 30), and regular physical exercise.

Hospital and death records were then used to identify stroke events over an average follow-up of 7 years.

Across all categories of genetic risk and lifestyle, the risk of stroke was higher in men than women.

Risk of stroke was 35% higher among those at high genetic risk compared with those at low genetic risk, irrespective of lifestyle. However, an unfavourable lifestyle was associated with a 66% increased risk of stroke compared with a favourable lifestyle, and this increased risk was present within any genetic risk category.

A high genetic risk combined with an unfavourable lifestyle profile was associated with a more than twofold increased risk of stroke compared with a low genetic risk and a favourable lifestyle.

These findings highlight the benefit for entire populations of adhering to a healthy lifestyle, independent of genetic risk, say the researchers. Among the lifestyle factors, the most significant associations were seen for smoking and being overweight or obese.

This is an observational study, so no firm conclusions can be drawn about cause and effect, and the researchers acknowledge several limitations, such as the narrow range of lifestyle factors, and that the results may not apply more generally because the study was restricted to people of European descent.

However, the large sample size enabled study of the combination of genetic risk and lifestyle in detail. As such, the researchers conclude that their findings "highlight the potential of lifestyle interventions to reduce risk of stroke across entire populations, even in those at high genetic risk of stroke."

Routine oxygen therapy is not recommended for hospital patients because the benefit is uncertain and there are clear harms, say a panel of international experts in The BMJ today.

Their advice is based on new evidence that too much oxygen increases risk of death and is part of The BMJ's 'Rapid Recommendations' initiative - to produce rapid and trustworthy guidance based on new evidence to help doctors make better decisions with their patients.

Oxygen therapy is widely used in hospitals and it is usual care to give extra oxygen to sick patients, often with relatively little attention paid to when to start and stop it. Guidelines also vary in their advice on when to give oxygen and how much to give.

Oxygen levels are measured by blood saturation (SpO2) - the amount of hemoglobin in the bloodstream that is saturated with oxygen to carry it through the body. Normal oxygen saturation is usually between 96% and 98%, but sick patients are often kept close to 100%.

However, a recent evidence review published in The Lancet found that giving extra oxygen to hospital patients with normal oxygen levels increases mortality. Its authors concluded that oxygen should be given conservatively, but they did not make specific recommendations on how to do it.

So an international panel - made up of specialist doctors, a nurse, a surgeon, and patients - met to discuss this latest evidence and formulate a recommendation.

Using the GRADE approach (a system used to assess the quality of evidence), they make a strong recommendation to stop oxygen therapy in patients with a saturation of 96% or higher.

For patients who have had a heart attack or stroke, they suggest not starting oxygen therapy when levels are between 90% and 92% saturation, and they strongly recommend not starting oxygen therapy when levels are at or above 93% saturation.

There was not enough evidence to say exactly when oxygen should be started for many other medical conditions such as infections.

For most patients, they say a target of 90-94% saturation seems reasonable and is low enough to avoid harm. In all cases, they advise using the minimum amount of oxygen necessary.

The authors point out that while their recommendations apply to most patients, they do not apply to surgical patients, babies, or patients with a few other uncommon conditions. And they say their recommendations may be altered as new evidence emerges.

A new study in the Journal of Public Health indicates that advertising for alcohol is common in British television, and may be a potential driver of alcohol use in young people.

It is estimated that the rate of alcohol consumption in those over 15 in the UK is the eighth highest in Europe. Alcohol use was responsible for at least 6813 deaths in the country in 2015, and cost the NHS £3.5 billion in 2013-14.

There is strong evidence that exposure to advertising or other alcohol imagery in the media increases subsequent use in adolescents. An estimated 28 million British households have at least one television and in 2015 the average viewing was 3 hours and 47 minutes a day. Previous studies have found that alcohol imagery appeared frequently in studies of UK television; some 40 per cent of programs contained alcohol content.

In 2015, researchers quantified the content of all programs and advertisements broadcast on the five, free access, national UK channels. The researchers here explored the differences in content between channels and genres, and compared these with the findings of a similar study in 2010.

A total of 611 programs and 1140 commercials were recorded during the peak viewing hours, between 6 and 10 pm, from Monday to Sunday in three separate weeks. Alcohol imagery occurred most frequently in the news, current affairs programs, and soap operas.

This study demonstrates that alcohol imagery is extremely common on UK television, occurring in over 50% of all programs broadcast and almost 50% of all advertising periods between programs. The majority of alcohol content occurred before 9 pm. Branding occurred in 18% of programs and 11% of advertisement periods and involved 122 brands, though three brands (Heineken, Corona, and Fosters) accounted for almost half of all brand appearances.

Alcohol content shown on TV has an effect on the uptake of alcohol use in young people. This analysis shows that television remains a major source of alcohol exposure to young people in the UK and is likely to continue to be a contributor to alcohol uptake by young people, with levels of content slightly higher than the researchers observed in the earlier analysis of program content from 2010.

"There is strong evidence that viewing alcohol advertising or imagery has an uptake on subsequent alcohol use in young people," said Alexander Barker, research fellow at the Centre for Tobacco and Alcohol Studies. "Our study shows that alcohol imagery, including branding, is regularly broadcast on prime-time TV, when children and adolescents are likely to be watching. Tighter scheduling rules from the Advertising Standards Agency and Ofcom (broadcast regulator), such as restricting alcohol advertisements and alcohol imagery in programs, to after the 9 p.m. watershed, could prevent children and adolescents being exposed to this content."

Despite the conventional belief that for women giving birth “once a cesarean always a cesarean,” the practice of attempting vaginal delivery after cesarean — also known as “trial of labor after cesarean delivery” (TOLAC) — is safe for many second-time mothers with no contraindications. However, hospitals differ widely in how frequently and how well they use TOLAC, say Yale researchers. This study appears online in the American Journal of Obstetrics and Gynecology.

"Today, more than 30% of births in the U.S. are delivered via cesarean section," said Xiao Xu, lead author on the study and associate professor of obstetrics, gynecology, and reproductive sciences at the Yale School of Medicine. "This high rate of cesarean delivery not only affects the current birth but also future pregnancies as well since maternal risks for adverse outcomes progressively increase with each additional cesarean. So appropriate use of TOLAC plays an important role for improving long-term reproductive health of American women."

Examining data from the linked Californian hospital discharge records and birth certificates from 2010 to 2012, the researchers found that overall 12.5% of mothers with one prior cesarean delivery were able to give birth vaginally. Across hospitals, however, the rate of TOLAC use and subsequent success varied considerably -- with a median of 30.0% and 30.2%, respectively. The team then uncovered an inverted U-shaped relationship: Both excessively low or high TOLAC use was associated with lower success rates at any given hospital.

Additionally, whether hospitals in the study were more or less likely to have greater TOLAC use and success was linked with certain characteristics. Hospitals in rural locations and with higher local malpractice insurance premiums had lower TOLAC use, and hospitals with for-profit ownership had lower TOLAC success. Meanwhile, hospitals with both higher TOLAC use and success rates were those with teaching status, system affiliation, larger volume, higher neonatal care capacity, greater anesthesia availability, a higher proportion of midwife-attended births, and a lower proportion of Medicaid or uninsured patients.

"Understanding how and why hospitals differ in providing trial of labor for women after a previous cesarean can help us identify opportunities for improvement," said Dr. Jessica Illuzzi, senior author on the study and associate professor of obstetrics, gynecology, and reproductive sciences at Yale.

"For example, we found that low-volume and rural hospitals tend to have lower TOLAC use, so for those hospitals, exploring ways to safely support labor after cesarean can be beneficial to women in these regions," said Illuzzi. "In addition, some hospitals demonstrated successful vaginal delivery rates above 60% when attempting labor after a previous cesarean, so optimizing labor after cesarean for women at other hospitals can be an important and feasible way to reduce repeat cesarean delivery and associated maternal morbidities."

Rates of premature mortality are two times higher in the most deprived areas of England (Blackpool), compared to the most affluent (Wokingham), according to a new comprehensive analysis of health at a local, national and regional level across the UK.

In addition, the study reveals the huge burden of disability linked to long-term conditions such as low back and neck pain, anxiety and depression, highlighting the need for health services to adapt to managing these conditions.

While overall rates of premature death have improved since 1990, half of all premature deaths in 2016 were linked to risk factors including tobacco use, unhealthy diet, alcohol and drug use, obesity and high blood pressure, pointing to the urgent need for policies and programmes targeting prevention, especially in areas outside the control of the health service.

The study, from the Global Burden of Disease initiative, provides data on premature mortality, disability and risk factors from 1990 to 2016 for 150 Upper-Tier Local Authority (UTLAs) in England, as well as Scotland, Northern Ireland and Wales, with the aim of informing resource allocation and priorities at a local, regional and national level.

Years lived with disability exceed years of life lost

Ischaemic heart disease was the leading cause of premature death in the UK in 2016, and rates were two times higher in men than in women. Self-harm was the third leading cause of premature death for men.

In England, Wales and Northern Ireland (but not Scotland), the years lived with disability exceeded the years of life lost. Low back and neck pain, skin and subcutaneous diseases, migraine, depressive disorders, sense organ disorders and anxiety disorders were the leading causes of disability.

"As death rates decrease, people continue to live with long-term, often multiple, conditions," says Professor Nicholas Steel, lead author, University of East Anglia, UK. "Our findings show a significant shift from mortality to morbidity, yet our health services are still designed to deal with the big killers. Today, conditions such as back and neck pain and anxiety and depression are huge causes of disability in the UK." [1]

Health and deprivation

Rates of premature mortality from all causes were more than two times higher in the most deprived UTLAs in England (Blackpool), compared to the most affluent (Wokingham, Surrey, Windsor and Maidenhead, and West Berkshire). Rates of premature mortality were consistently higher for the 15 most deprived areas of England, compared to the 15 least deprived, and the association with deprivation was particularly strong for lung cancer, and chronic obstructive pulmonary disease.

In England, some UTLAs performed better than expected for their level of deprivation. For instance, Birmingham and some London boroughs (eg. Tower Hamlets and Hackney) performed better than UTLAs with similar levels of deprivation in Liverpool and Manchester, strengthening the need for specific action to respond to the distinct problems that might exist in northern cities.

The authors also suggest that the relatively better health seen in London may be because of lower levels of risk factors such as smoking and poor diet; better access to health care; higher educational performance; or the selective movement of sicker people outside London, and of healthier people to London for work.

Professor John Newton, author and director of health improvement at Public Health England, UK, said: "This comprehensive assessment of health across the country highlights the stark division between rich and poor areas, which sees poorer people dying earlier and getting sicker quicker. It also shows the improvements to health that could be achieved by addressing underlying causes, such as poverty, education and other resources needed for good health." [1]

"As we work to develop the NHS long term plan, actions tackling the social and structural drivers of ill health are needed if we're to improve the stubborn health gap between rich and poor areas of the country." [1]

Northern Ireland had particularly high rates of anxiety disorders, which have been attributed to the social and economic legacy of civil conflict. Premature mortality remains higher in Scotland than in England, with higher rates of cardiovascular disease, cancer and cirrhosis. The authors note that the long-standing differences between the countries of the UK are likely to be due to variations in risk factors and socioeconomic deprivation, rather than differences in health service organisation and spending.

Health improvements have slowed since 2010

Between 1990 and 2016, life expectancy has improved in all four countries of the UK, but the rate of improvement has slowed since 2010. Nine out of 150 UTLAs [2] had worse rates of premature death in 2016, compared to 2010.

Rates of premature death varied by cause, and the national slow-down in improvements since 2010 was mainly driven by the gradual disappearance of improvements in ischaemic heart disease, cerebrovascular disease, and to a lesser extent colorectal cancer, lung cancer, and breast cancer. The slow-down in improvements in cardiovascular deaths was seen in most age groups, but this was most apparent in those aged over 85 years.

"The worsening trend in mortality for some cancers is a concern, especially given evidence that survival from some common cancers in the UK is worse than in other European countries," explains Professor Steel. [1]

More affluent UTLAs saw the greatest improvements in mortality before 2000, but this changed after 2010 when the national slow-down in mortality improvements was more substantial in affluent areas than in more deprived UTLAs. However, the reasons for this are unclear and more research is needed into the links between deprivation and mortality since 2010.

The need for action outside the health service

In all four countries, over half of premature deaths are linked to behavioural risk factors including tobacco use, unhealthy diet, obesity, alcohol and drug use, low physical activity, and environmental factors, such as air pollution.

"In many cases, the causes of ill health and the behaviours that cause it lie outside the control of health services. Our results argue for policies and programmes that deter the food industry from a business model based on cheap calories, that promote and sustain healthy built and natural environments, that help people stop smoking, and that encourage a healthy drinking culture. The same level of attention that has previously been given to the prevention of cardiovascular disease and cancer now needs to be directed at other major causes of mortality such as liver disease and dementia, and associated risk factors including unhealthy diets, alcohol, air pollution and drug misuse," says Professor Steel [1].

The ten leading risk factors ranked similar across the four countries of the UK, with higher rates of tobacco use in Scotland, and of alcohol and drug use in Scotland and Northern Ireland.

"All countries in the UK could further reduce the burden of disease through effective prevention. Good progress has been made on reducing the prevalence of smoking to historic lows, but there is scope to do much more in almost all areas of prevention. Health services need to realise that prevention is a core activity, not an optional extra to be undertaken if resources allow," he says [1].

Since 2010, the annual rate of reduction of premature deaths linked to most major risk factors has slowed - apart from alcohol which has remained roughly unchanged since 2000. The continued dominance of cardiovascular disease as the leading cause of mortality argues for renewed efforts to deliver systematic programmes to reduce risk factors such as high body mass index, high fasting glucose, high blood pressure and high cholesterol (all ranked in the top 10 risk factors in the UK).

Finally, the authors note that improved data are needed to estimate morbidity trends across the UK. The UTLA-level data on morbidity (or disability) is subject to greater uncertainty than the mortality data.

Dr Christopher Murray, Institute for Health Metrics and Evaluation at the University of Washington, USA, says: "The estimation of disease burden at the very local UTLA level in England is unprecedented in the twenty plus-year history of the Global Burden of Disease Study. These local findings demonstrate to other countries the value of empowering policymakers to make more effective health decisions that address specific needs of very specific communities." [1]

Writing in a linked Comment, Ellen Nolte, London School of Hygiene & Tropical Medicine, UK, highlights previous research (Rutter et al.) showing that a series of single, unlinked, interventions that require the individual to act (for example, making healthy choices on the basis of traffic light labelling of food or taking up exercise on prescription) are unlikely to have an effect on complex problems such as obesity. Instead, she says: "There is a need for a wider policy framework that is mindful of the potential tensions and unintended consequences of policies that are not consistent, recognises the influence of powerful corporate actors in undermining public health policies that seek to promote health, and creates a policy environment that provides the means for those who are asked to implement change to acquire the capacity and competence to do so."

Life-changing moments are also brain-changing moments: everything from a first kiss to a last goodbye modifies cells within the skull. The capacity to learn and remember, however, extends beyond the profound experiences that we lament or treasure. In fact, a new study led by Rockefeller scientist Charles D. Gilbert suggests that even when we're not consciously forming new memories, our brains can change in important ways, altering how we interpret and interact with the world.

"Some connections in brain are fixed after a period in early life, known as the critical period," says Gilbert, the Arthur and Jane Ross Professor of Neurosciences and Behavior. "Others are changing throughout life, and play an important role in encoding information in our brain as we encounter new experiences."

Perceiving is believing

The study, published in the Proceedings of the National Academy of Sciences, focused on perceptual learning, a process that involves tuning the senses to better perceive the subtleties of various sights, sounds, and smells. Most of the time, we're not aware that we've become better at distinguishing between two different shapes, for instance; but over time, with repeated exposure, this type of unconscious learning indeed takes place.

Scientists have long known that the brain can remodel itself, both as a result of normal memory formation and as a way to recover from brain damage. Gilbert had previously shown, for example, that when recovering from brain injury, neurons grow new axons, the threads that transmit signals to other cells. And he has long believed that this type of change might also occur under normal circumstances.

"We had always suspected that this ability to form new connections in the adult brain isn't something that just evolved as a way to recover after injury," says Gilbert. "Rather, it's a mechanism that we're using in our brains all the time."

What's more, disruptions to that mechanism could underlie some brain disorders, Gilbert says. "This type of neuronal flexibility happens in areas outside of perception," he notes. "So if that mechanism gets disturbed, it may account for behavioral disorders such as autism and schizophrenia."

Can you see it?

To test whether remodeling occurs in brain regions devoted to vision, Gilbert and his colleagues challenged two macaque monkeys to perceive elements of order within otherwise disordered scenes. During experiments, the monkeys viewed two pictures side by side. Both contained a frenzy of dashes, but in one image some of these dashes came together to form a cohesive line. The monkeys' task was to identify the line--and the fewer dashes it contained, the harder it was to spot.

Initially, the monkeys succeeded only during the easy rounds, when the lines consisted of nine dashes. With weeks of training, however, they mastered increasingly difficult trials, and one animal was eventually able to spot a line only three dashes long.

"The animal didn't need a reward to move his eye in the direction of the image that contained a line," says Gilbert. "Just by doing the same task over and over, he improved."

Throughout the experiment, the researchers tracked cellular changes in the visual cortex, a brain region that receives and processes signals from the eye. They found that, as the animals got better at the task, visual cortex neurons sprouted new axons and shed some old ones. These findings show that the circuitry of the adult brain is constantly changing, a quality known as plasticity.

"We've always known the brain needs some degree of plasticity through adulthood so that we can acquire new memories," says Gilbert. "But it turns out that plasticity is more ubiquitous than we initially thought."

RICHLAND, Wash. - Taste might have less to do with what consumers are willing to pay for wine than you think.

In fact, issues like a wine's country and region of origin sometimes had more impact on a person's willingness to pay more for a wine than taste.

The trend was revealed in a study by university researchers from Washington state, Minnesota, Hong Kong and Korea.

Researchers found through a series blind taste tests that 'nontaste-related factors' may play a larger role in how much consumers are willing to pay for wine in Hong Kong, compared with their western counterparts.

Project researchers included Byron Marlowe, a clinical assistant professor in hospitality business management at Washington State University Tri-Cities, and colleagues at the University of Minnesota, Hong Kong Polytechnic University and Gyeongsang National University in Korea, Their results are presented the fall issue of the British Food Journal.

Three stages of research

The test was administered in three stages.

Stage 1: A purely blind tasting test, in which participants received no information about the wine.

State 2: Participants were provided with the wine's country of origin prior to the tasting.

Stage 3: Full information on the wines, including attributes such as grape variety, region and winery of origin, were provided before tasting.

During each tasting, participants were asked to taste and rate each wine according to selected attributes and assign their "willingness-to-pay" for that particular wine. Six wines -- three reds and three whites, with similar price points, from five different countries and six different regions -- were served in each stage. The wine originated from the following areas:

Western Cape, South Africa

Iowa, USA

Rheingau, Germany

Rioja, Spain

Wisconsin, USA

Argentina

"Most of the wines did fairly well in the first treatment, when all of the individuals were completely blind to the wine details," Marlowe said. "But they do worse when revealed that the wines are from regions that they are not as familiar with or with varietals that they aren't familiar with."

Pre-taste factors that impact willingness to pay

Researchers found that revealing the country and region of origin of the wines from Iowa and Wisconsin had a negative effect on how much participants were willing to pay per bottle. Customers indicated they would be willing to pay an average of $2.70 to $4.80 less per bottle than the designated stated retail price for the wines.

For example, if the wine's stated retail price was $24, then the customer would be willing to pay potentially $2.70 to $4.80 less than that price, or $21.30 or $19.20 per bottle.

Marlowe said this is probably because those regions are not widely known as wine grape-growing regions, and also not for wine production.

"All of a sudden, when participants know they're drinking a wine from the Midwest, where cold and hardy varietals are grown, their immediate response is to rate it lower than wine from a more well-known region," he said.

Similar results were shown for the wines from Germany and Argentina, although further analysis found the two countries to be less effected by perception of region.

Researchers also realized that female participants in the study seemed to have higher willingness to pay than males. Younger consumers also appeared to have higher willingness to pay than older consumers.

Additionally, "novice drinkers" or those who had wine rarely or less than once a month, relied mainly on country of origin information in their wine evaluations, as compared to "expert consumers" or those who drink wine more than once a week and who relied more on sensory quality or taste, according to results of the study.

Asian vs. western market perceptions

Although results of Hong Kong participants follow similar trends as those who participated in similar studies in western countries, results also suggest that cues unrelated to taste play a larger role in the evaluation of wine in the Asian market, especially for novice wine drinkers, as compared to western societies.

Marlowe said these points warrant attention as wine consumption and popularity continues to grow in Asia, and specifically Hong Kong..

"Teachers, wine scientists and marketers can use these details when marketing wines for Asian countries, as well as in educating individuals in those areas about wine origins and attributes," Marlowe said. "A wine produced in the Midwest in the United States may be a premium wine, but if there is a perception that it is less than, we need to overcome those factors through marketing and business tactics to help promote those wines."

Scientists at Tokyo Institute of Technology, RIKEN and Tohoku University have developed a silicone polymer chain that can self-assemble into a 3D periodic structure. They achieved this by using their recently reported self-assembling triptycene molecules to modify the ends of the polymer chains.

The development of novel soft materials for various optical, mechanical, heat/charge transportation and nanotechnological applications would greatly benefit from techniques to create polymer assemblies in periodically ordered structures. Such ordered structures are created using molecular scaffolds or by modifying certain parts of the polymers used so that they self-assemble into the desired shape.

However, researchers nowadays consider that terminal functionalization (modifying both ends of a polymer chain) is not very effective for creating periodically ordered structures. That's why scientists from Tokyo Institute of Technology (Tokyo Tech), led by Fumitaka Ishiwari, were interested in revisiting one of their recently developed triptycene molecules, called 1,8,13-Trip. The team had already demonstrated that this molecule can reliably self-assemble into a periodic 3D structure made of parallel 2D sheets separated from each other by a fixed distance (see Fig. 1). "We were interested in investigating whether the powerful self-assembling ability of this triptycene motif would also operate in polymer systems," explains Ishiwari.

Therefore, the team designed polydimethylsiloxane (PDMS) chains with the ends replaced by a triptycene molecule. They hoped that these modified silicone chains would also exhibit the promising self-assembling behavior observed for 1,8,13-Trip alone, and thus had to run many different experiments to prove it, including Synchrotron-Radiation X-ray diffraction/scattering using the BL45XU beamline at SPring-8 (Hyogo, Japan), differential scanning calorimetry and spectroscopy measurements. Fortunately, all results seemed to indicate that the modified PDMS chains had self-assembled into the 3D periodic structure shown in Fig. 2. This was also verified by analyzing the differences in the flow characteristics of the modified PDMS chains and regular PDMS chains.

The team's findings are very promising because the triptycene motif used is simple and easy to synthesize via short steps, and may provide a powerful tool for organizing polymers and reinforcing their structural and physical properties. "The present finding will update the general notion that terminal functionalization is not effective for achieving the controlled assembly of polymers into a periodically ordered structure," concludes Ishiwari. The team will carry on investigating the self-organization of polymers, and it is hoped that the results will lead to the development of novel materials and synthesis techniques.

Professor Masaki Takata of Tohoku University attributed the success of the study to the collaborative efforts of the Network Joint Research Center for Materials and Devices and the large scale Synchrotron Radiation facility, SPring-8, managed by RIKEN. He added that "this would hopefully also trigger a big demand for further high quality materials, which can be developed at the next-generation 3GeV synchrotron facility, due to begin construction at Tohoku University next year."

New research, published today (Wednesday 24 October) in the journal Monthly Notices of the Royal Astronomical Society, has found evidence for a large number of double supermassive black holes, likely precursors of gigantic black hole merging events. This confirms the current understanding of cosmological evolution - that galaxies and their associated black holes merge over time, forming bigger and bigger galaxies and black holes.

Astronomers from the University of Hertfordshire, together with an international team of scientists, have looked at radio maps of powerful jet sources and found signs that would usually be present when looking at black holes that are closely orbiting each other.

Before black holes merge they form a binary black hole, where the two black holes orbit around each other. Gravitational wave telescopes have been able to evidence the merging of smaller black holes since 2015, by measuring the strong bursts of gravitational waves that are emitted when binary black holes merge, but current technology cannot be used to demonstrate the presence of supermassive binary black holes.

Supermassive black holes emit powerful jets. When supermassive binary black holes orbit it causes the jet emanating from the nucleus of a galaxy to periodically change its direction. Astronomers from the University of Hertfordshire studied the direction that these jets are emitted in, and variances in these directions; they compared the direction of the jets with the one of the radio lobes (that store all the particles that ever went through the jet channels) to demonstrate that this method can be used to indicate the presence of supermassive binary black holes.

Dr Martin Krause, lead author and senior lecturer in Astronomy at the University of Hertfordshire, said: "We have studied the jets in different conditions for a long time with computer simulations. In this first systematic comparison to high-resolution radio maps of the most powerful radio sources, we were astonished to find signatures that were compatible with jet precession in three quarters of the sources."

The fact that the most powerful jets are associated with binary black holes could have important consequences for the formation of stars in galaxies; stars form from cold gas, jets heat this gas and thus suppress the formation of stars. A jet that always heads in the same direction only heats a limited amount of gas in its vicinity. However, jets from binary black holes change direction continuously. Therefore, they can heat much more gas, suppressing the formation of stars much more efficiently, and thus contributing towards keeping the number of stars in galaxies within the observed limits.

Chemical communication is widely used in the animal kingdom to convey social information. For example, animals use olfactory cues to recognize group or family members, or to choose genetically suitable mates. In contrast to most other mammals, however, primates have traditionally been regarded as "microsmatic" - having a poor sense of smell. Although research on olfaction in some primate species has increased in recent years, non-human great apes have been greatly neglected in these studies. Researchers from the University of Leipzig and the Max Planck Institute for Evolutionary Anthropology as well as Durham University have now conducted one of the first studies investigating the signaling function of social odors in non-human great apes.

The scientists presented two groups of chimpanzees with urine from group members, strangers and an unscented control in aerated plexiglass boxes and videotaped their behavior. Chimpanzees sniffed longer at urine than at the control, suggesting they perceive the odor of other chimpanzees. More importantly, they discriminated between the smell of group members and strangers, sniffing outgroup odors longer than ingroup odors. "Chimpanzees are highly territorial, and encounters between groups are mostly hostile - in fact, they sometimes kill individuals from other communities - so olfactory cues might help them to locate other animals and determine whether they are group members or strangers, enhancing their survival and leading to fitness benefits", says lead author Stefanie Henkel of the University of Leipzig and the Max Planck Institute for Evolutionary Anthropology. "Odor might be especially important because most chimpanzees live in dense forests where visibility is low, and because in chimpanzee societies, group members split up into subgroups that may not see each other for days", Henkel adds.

Furthermore, the researchers found that chimpanzees sniffed longer at the odor the more closely related they were to the odor donor, providing the first evidence for odor-mediated kin recognition in non-human great apes. "The ability to recognize kin is crucial, because it allows animals to choose appropriate partners for coalitions, avoid mating with close relatives, and avoid killing their own offspring", co-author Jo Setchell explains. "There is evidence that humans can also recognize the smell of their relatives, even as newborns. We apparently retained good olfactory capabilities, although we - like our closest relatives, the chimpanzees - don't usually scent-mark, and lack the specialized olfactory system found in many other animals. Our results help us to understand the evolution of primate chemical communication and suggest that we should pay more attention to olfaction in apes".

"Interestingly, in the vast majority of cases, the first investigatory behavior the chimpanzees showed when they approached a box for the first time was related to olfaction, rather than touch or just visual inspection", Henkel points out. "To me it is very surprising that research on great ape olfaction has been neglected for so long, particularly given the increasing evidence for the importance of olfaction in other primate taxa, including humans. Our results highlight the importance of the sense of smell in chimpanzees and there is great potential for future studies to investigate the full information content of different ape odor sources using chemical analyses and further behavioral experiments".

More than 10 million tons of plastic debris enter the oceans every year and are found in nearly every oceanic layer. They start out as large floating items and eventually break down into much smaller pieces called microplastics. These particles are pervasive and have been found in the digestive tracts of more than 100 different species, posing physical, chemical and even potential biological harm to these animals. Mussels and other bivalves like oysters and clams are eaten whole without removal of the gastrointestinal tract and therefore represent a pathway for microplastics to enter the human food chain.

Contrary to prior research, a first-of-its-kind study from a team of scientists suggests that mussels are not a robust indicator of microplastics in the marine environment because of their inherent ability to selectively feed, making them very picky eaters. Instead, marine aggregates, also referred to as "marine snow," have much more to say about the fate of microplastics in the environment.

Marine aggregates are a predominant form of sinking particulate carbon in the marine water column and form the basis of the food chain in the ocean. These aggregates also represent a mechanism for transporting microplastics to the sea floor. The study demonstrates that they play an important role in removing microplastics from the ocean surface, vertically transferring them through the water column, and facilitating their transfer to marine food webs.

Using a powerful tool called spectroscopy, researchers from Florida Atlantic University, East China Normal University, Woods Hole Oceanographic Institution, the University of Connecticut, and the University of New England, are the first to identify a connection, under field conditions, between microplastics within marine aggregates and mussels (Mytulis edulis). Results of the study, published in the journal Environmental Science & Technology, have important implications for the fate of plastic particles in marine environments.

"We suspected that suspension-feeding bivalves like mussels would particularly be impacted by plastic-laden marine aggregates," said Tracy J. Mincer, Ph.D., co-author and a research professor at FAU's Harbor Branch Oceanographic Institute and FAU's Harriet L. Wilkes Honors College. "We wanted to better understand the link between marine aggregates, microplastics and marine animals, especially bivalves, in the environment."

For the study, the researchers collected marine aggregates and blue mussels at Avery Point in Connecticut and used microscopy and microspectrometry to measure the spectra of these microscopic samples. They found that 73 percent of the marine aggregates they sampled contained plastic particles. More than 90 percent of these microplastics measured less than 1 millimeter.

In the mussels, the researchers detected microplastics in the biodeposits or digestive gland/gut of nearly all of the mussels they collected from the Avery Point dock. More than 40 percent of the microplastic particles were either rejected in the mussels' pseudofeces or egested (discharging undigested material) in feces. Normally, mussels can digest their food within a matter of minutes. In contrast, the plastic particles passed to the digestive diverticula of the mussels took days to digest.

The characteristics of microplastics in the marine aggregates and mussels were similar, which provided further evidence of marine aggregates' role in the trophic transfer of plastic particles to bottom suspension-feeders.

The uniformity of microplastic sizes and shapes identified within the mussels indicated that selective ingestion of certain types of plastics occurred. The mussels preferentially ingested particles of a smaller size and a relatively larger shape factor.

"The good news is that mussels are picky eaters and have well-developed mechanisms for particle discrimination," said Mincer. "They sort particles based on physical features like size, shape, flexibility and density as well as chemical and nutritional properties. Particle selection is one strategy that they use to enhance their diet quality and optimize energy intake."

The chemical composition from these marine aggregates were diverse and included a broad range of domestic and industrial uses. Polypropylene, polyester and cellulose acetate, commonly used in cigarette filters, hygiene products, and clothing, made up nearly 76.3 percent of all plastic particles identified in the sampled marine aggregates. Cellulose acetate is primarily introduced into marine environments via sewage discharge, and cigarette butts are a major coastal ocean input mechanism as well.

An unexpected finding from the study was that fragmented plastics were the predominant type of synthetic particles identified in the marine aggregates and accounted for 65.9 percent of all microplastics.

The researchers compared the abundances of plastic particles in the marine aggregates with other reports worldwide. They also found that the concentration of microplastics in the mussels they sampled was about three times lower than those found in wild mussels from China's coastal waters.

The trillions of bacteria in the human gut affect our health in multiple ways including effects on immune functions and metabolism. A rich and diverse gut microbiota is considered to promote health providing the human host with many competences to prevent chronic diseases. In contrast, poor diversity of the gut ecosystem is a characteristic feature of chronic diseases including obesity, diabetes, asthma and gut inflammatory disorders.

Due the general bacterial-killing nature of antibiotics, it has been speculated that repetitive use of antibiotics deprives people of a rich gut bacterial environment and through this lead to adverse health effects.

Now, an international team of researchers led from the University of Copenhagen and Steno Diabetes Center Copenhagen report when 3 antibiotics were given to young healthy men for 4 days it caused an almost complete eradication of gut bacteria, followed by a gradual recovery of most bacterial species over a period of six months.

After the six months, however, the study participants were still missing nine of their common beneficial bacteria and a few new potentially non-desirable bacteria had colonized the gut. The findings are published today in Nature Microbiology.

"We show that the gut bacterial community of healthy adults are resilient and able to recover after short-term simultaneous exposure to three different antibiotics However, our findings also suggest that exposure to broad-spectrum antibiotics may dilute the diversity of the intestinal bacterial ecosystem. Antibiotics can be a blessing for preserving human health but should only be used based upon clear evidence for a bacterial cause of infection," explains study lead , Professor Oluf Pedersen, Novo Nordisk Foundation Center for Basic Metabolic Research.

Is the missing beneficial gut microbes in the Western world due to over usage of antibiotics?

The study is a four-day intervention with three broad-spectrum so-called "last-resort" antibiotics in 12 adult healthy men. The method with a cocktail of three antibiotics was designed to mimic actual treatments in intensive care units.

The gut is a reservoir of hundreds of different bacterial species with antibiotic-resistant genes. This was confirmed in the study as these bacterial genes were the initiating force that led to the replenishment of bacteria in the gut.

"In this case, it is good that we can regenerate our gut microbiota which is important for our general health. The concern, however, relates to the potentially permanent loss of beneficial bacteria after multiple exposures to antibiotics during our lifetime. There is evidence that Western populations have a considerably lower diversity of their gut microbiota that native people living in certain parts of Africa and Amazonas. One possible explanation for this may be the widespread use of antibiotics in treatment of infectious diseases," says Oluf Pedersen.

RIVERSIDE, Calif. – Galaxy clusters are rare regions of the universe consisting of hundreds of galaxies containing trillions of stars, as well as hot gas and dark matter.

It has long been known that when a galaxy falls into a cluster, star formation is fairly rapidly shut off in a process known as "quenching." What actually causes the stars to quench, however, is a mystery, despite several plausible explanations having been proposed by astronomers.

A new international study led by astronomer Ryan Foltz, a former graduate student at the University of California, Riverside, has made the best measurement yet of the quenching timescale, measuring how it varies across 70 percent of the history of the universe. The study has also revealed the process likely responsible for shutting down star formation in clusters.

Each galaxy entering a cluster is known to bring some cold gas with it that has not yet formed stars. One possible explanation suggests that before the cold gas can turn into stars, it is "stripped" away from the galaxy by the hot, dense gas already in the cluster, causing star formation to cease.

Another possibility is that galaxies are instead "strangled," meaning they stop forming stars because their reservoirs cease getting replenished with additional cold gas once they fall inside the cluster. This is predicted to be a slower process than stripping.

A third possibility is that energy from the star formation itself drives much of the cold gas fuel away from the galaxy and prevents it from forming new stars. This "outflow" scenario is predicted to occur on a faster timescale than stripping, because the gas is lost forever to the galaxy and is unavailable to form new stars.

Because these three different physical processes predict galaxies to quench on different relative timescales over the history of the universe, astronomers have postulated that if they could compare the number of quenched galaxies observed over a long time-baseline, the dominant process causing stars to quench would more readily become apparent.

However, until recently, it was very difficult to find distant clusters, and even harder to measure the properties of their galaxies. The international Spitzer Adaptation of the Red-sequence Cluster Survey, or SpARCS, survey has now made a measurement of more than 70 percent of the history of the universe, accomplished by pioneering new cluster-detection techniques, which enabled the discovery of hundreds of new clusters in the distant universe.

Using some of their own newly discovered SpARCS clusters, the new UCR-led study discovered that it takes a galaxy longer to stop forming stars as the universe gets older: only 1.1 billion years when the universe was young (4 billion years old), 1.3 billion years when the universe is middle-aged (6 billion years old), and 5 billion years in the present-day universe.

"Comparing observations of the quenching timescale in galaxies in clusters in the distant universe to those in the nearby universe revealed that a dynamical process such as gas stripping is a better fit to the predictions than strangulation or outflows," Foltz said.

To make this state-of-the art measurement, the SpARCS team required 10 nights of observations with the W. M. Keck Observatory telescopes (10 meters in diameter) in Hawaii, and 25 nights of observations with the twin Gemini telescopes (8 meters in diameter) in Hawaii and Chile.

"Thanks to the phenomenal investment in our work by these observatories, we now believe we have a good idea of how star formation stops in the most massive galaxies in clusters," said Gillian Wilson, professor of physics and astronomy at UCR and leader of the SpARCS survey, in whose lab Foltz worked when the study was done. "There are good reasons, however, to believe that lower-mass galaxies may quench by a different process. That is one of the questions our team is working on answering next."

The team has been awarded 50 additional nights of Gemini time and a $1.2 million grant from the National Science Foundation to study how star formation stops in more regular-mass galaxies. Wilson was also awarded Hubble Space Telescope observations and a NASA grant to analyze high-resolution images of the quenching galaxies.

The research paper is published in the Astrophysical Journal.

Claims by the tobacco industry that heated tobacco products (HTPs) are safer than conventional cigarettes are not supported by the industry's own data and are likely to be misunderstood by consumers, according to research published in a special issue of Tobacco Control.

The issue was assembled by Stanton A. Glantz, PhD, director of the UCSF Center for Tobacco Control Research and Education.

HTPs are aggressively promoted by the tobacco industry as less harmful than cigarettes because they heat tobacco rather than burn it to generate the aerosol that delivers nicotine to users' lungs. The industry argument is that because HTPs do not set the tobacco on fire, they release lower levels of harmful chemicals and so cause less disease than conventional cigarettes.

The papers, published October 23, 2018, represent the first comprehensive collection of industry-independent peer-reviewed analyses of HTPs.

Many of the papers focus on IQOS, an HTP sold by Philip Morris International (PMI) in 30 countries including Canada, Israel, Italy and Japan. The U.S. Food and Drug Administration (FDA) has not yet approved IQOS for sale in the United States. In the issue's introductory overview, Glantz noted that eight papers use data provided by PMI in its pending application to the FDA, while 12 provide independent assessments of IQOS and other HTPs, including their political and policy implications.

"Until now, most of the published research on HTPs had been done by tobacco companies," said Glantz. "We've seen this charade from Big Tobacco before, going back to the 1960s, and the goal is always the same: to convince governments and the public that a new tobacco product is 'safer,' 'cleaner' or 'less harmful' than existing tobacco products. But in paper after paper, the scientists writing in this issue demonstrate that the health and other claims made for IQOS and other HTPs are false and misleading."

Overall, said Glantz, the issue's contributors demonstrate that PMI's safety claims for HTPs are not supported by the company's own data, which further show that consumers are likely to misunderstand those claims. "While some impacts of IQOS may be lower than that of cigarettes, others may be as bad or worse," he said. "The evidence does not support PMI's broad claims of reduced harm." He noted that researchers also found that HTPs are not as new as the industry would have consumers believe, with precursor devices going back decades. In addition, HTPs may appeal to young people. A final set of papers describes how HTPs fit into the tobacco industry's global strategy to deal with increasing regulation worldwide; after a legal analysis, the authors conclude that the FDA should not allow IQOS to be sold in the U.S.

UCSF scientists contributed to 14 of the 22 papers. Among them are:

Stella Bialous, RN, DrPH, FAAN, UCSF associate professor of social behavioral sciences, and Glantz identified the introduction of HTPs as the latest in a line of similar past efforts by the tobacco industry to undermine government regulation of tobacco by marketing a new product as "safer" or representing "harm reduction." They called on governments to regulate HTPs as tobacco products or drugs, noting that tobacco companies are the "vector" for the tobacco epidemic and cannot be part of the global tobacco control solution.

Glantz analyzed PMI's publicly available data on biomarkers of potential harm and determined that there was no statistically detectable difference between IQOS and conventional cigarettes for 23 of 24 biomarkers of potential harm among American adult smokers, and no significant difference in 10 of 13 such biomarkers among Japanese adult smokers.

A team led by Jeffrey Gotts, MD, UCSF assistant professor of medicine, found that that HTPs could possibly cause some diseases not caused by conventional cigarettes. They identified animal and human studies in PMI's FDA application suggesting that IQOS may cause liver toxicity not observed in cigarette users.

Lauren Kass Lempert, JD, MPH, law and policy specialist, UCSF Center for Tobacco Control Research and Education, and Glantz wrote that the non-tobacco components of HTPs have escaped effective regulation in many countries because they are packaged and sold separately from the tobacco-containing components. Lempert and Glantz argued that in countries where IQOS is currently marketed, all components of HTPs should be regulated at least as stringently as other tobacco products. They also argued that because PMI has not submitted sufficient evidence that marketing IQOS in the United States would be "appropriate for the protection of the public health," the standard companies must meet to market new tobacco products in the U.S., the FDA should not authorize sale of IQOS in the United States.

A team led by UCSF professor of medicine Pamela Ling, MD, analyzed the marketing campaign for Accord, a failed HTP that was introduced by Philip Morris in the late 1990s and early 2000s. The researchers observed that unlike the Accord campaign, PMI seeks to market IQOS as having reduced health risk compared with cigarettes, even though it contains more nicotine and tar than Accord. The researchers attributed this shift in marketing claims to a looser social and regulatory environment rather than a significant improvement in the product's aerosol chemistry.

Another investigation led by Dr. Ling used previously secret tobacco industry documents to describe how R.J. Reynolds Tobacco Company quietly secured a 1991 editorial in The Lancet endorsing Premier, an earlier HTP, two years after Premier had been removed from the market. According to the authors, this historical case illustrates the importance of endorsements by respected health leaders and the need to insist on full disclosures of potential conflicts of interest. They noted that such endorsements are likely to play a critical role in determining the commercial fate of new HTPs, and may help the newest crop of modified tobacco products succeed where previous attempts have failed.

Wendy Max, PhD, UCSF professor of health economics and director of the Institute for Health & Aging in the UCSF School of Nursing, led a group that reviewed a computational model developed by PMI that compared the public health impact of cigarettes and HTPs on mortality from four diseases caused by smoking: lung cancer, ischemic heart disease, stroke and chronic obstructive pulmonary disease. PMI used results from the model as evidence for its claim that HTPs pose less health risk than cigarettes. The researchers found that the PMI model excludes morbidity, underestimates mortality, does not compare HTPs with any tobacco products other than cigarettes, does not include the potential of HTPs to initiate smoking among non-smokers and underestimates the health impacts of HTPs on nonsmokers.

Farzad Moazed, MD, UCSF assistant professor of medicine, led a research group that studied publicly available data submitted by PMI to the FDA and determined that, among human smokers, both IQOS and conventional cigarettes were associated with significant toxicity in the lungs and immune system, with no detectable difference in toxicity between the two. Additionally, rats exposed to IQOS showed evidence of pulmonary inflammation.

A group led by Gideon St. Helen, PhD, UCSF assistant professor of medicine, reviewed PMI's publicly available data comparing levels of 113 chemical constituents found in smoke from IQOS and conventional cigarettes. They found that 56 constituents were higher in smoke from IQOS, 22 were at least 200 percent higher and seven were at least a thousand percent higher. The potential harm that could be caused by these substances is unknown.

Matthew Springer, PhD, UCSF professor of medicine, led a team which showed that in rats, a single IQOS tobacco stick impaired the ability of arteries to become larger in response to increased blood flow to the same extent as smoke from a conventional cigarette. In addition, the team found that nicotine levels were about 4.5 times higher in rats after exposure to IQOS compared with cigarettes.

The papers from other institutions provided insights into how IQOS is being marketed in other countries, how users would misunderstand marketing claims, and adverse health effects of HTPs.

While the issue was assembled by Glantz, all the papers were independently peer-reviewed by outside editors selected by Tobacco Control.

"When it comes to regulating tobacco, governments, regulatory bodies and nonprofit agencies need to always keep in mind that the tobacco industry is the source of the problem and can never be part of the solution," said Glantz. "Tobacco companies exist to sell tobacco to as many consumers as possible, period. Partnering with them to control tobacco use or promote harm reduction is always going to be a losing strategy."

The entrainment of theta brain waves with a commercially available device not only enhances theta wave activity, but also boosts memory performance. That's according to new research from the Center for Neuroscience at the University of California, Davis, published recently in the journal Cognitive Neuroscience.

Electrical activity in the brain causes different types of brain waves that can be measured on the outside of the head. Theta waves occur at about five to six cycles per second, often associated with a brain that is actively monitoring something -- such as the brain of a rat navigating a maze.

In an earlier study, Charan Ranganath, professor of psychology, and colleagues at the Center for Neuroscience found that high levels of theta wave activity immediately before a memory task predicted better performance.

"Entrainment" devices use a combination of sound and lights to stimulate brain wave activity. The idea is that oscillating patterns in sensory inputs will be reflected in brain activity. The devices are marketed to address a range of problems such as anxiety, sleep issues, "low mood" and learning. However, there is very little published scientific evidence to support these claims.

Brooke Roberts, a postdoctoral researcher in Ranganath's lab, obtained a theta wave entrainment device and decided to test it. She had 50 volunteers either use the device for 36 minutes, or listen to 36 minutes of white noise, then do a simple memory test.

Improved memory performance

The subjects who had used the device showed both improved memory performance and enhanced theta wave activity, she found.

Roberts showed her results to Ranganath, who was intrigued but cautious and suggested new controls. They repeated the experiment with another 40 volunteers, but this time the control group received beta wave stimulations. Beta waves are a different type of brain wave pattern, occurring at about 12 to 30 cycles per second, associated with normal waking consciousness.

Once again, theta wave entrainment enhanced theta wave activity and memory performance.

Ranganath's lab also conducted a separate study using electrical stimulation to enhance theta waves. However, this actually had the opposite effect, disrupting theta wave activity, and temporarily weakened memory function.

Ranganath said he's surprised the devices work as well as they appear to do.

"What's surprising is that the device had a lasting effect on theta activity and memory performance for over half an hour after it was switched off," he said.

There is debate among neuroscientists over the function and role of these brain waves. Some researchers argue that they are simply a product of normal brain function with no particular role. Ranganath, however, thinks that they may play a role in coordinating brain regions.

"The neurons are more excitable at the peak of the wave, so when the waves of two brain regions are in sync with each other, they can talk to each other," he said.