Culture

Unsubstantiated health claims widespread within weight loss industry

New research investigating the legality of on-pack nutrition and health claims routinely found on commercially available meal replacement shakes for sale in the UK, reveals that more than three-quarters are unauthorised and do not comply with the EU Nutrition and Health Claims regulation.

This is one of the first studies to analyse how on-pack claims stack up to current regulation, and how much consumers actually understand and are influenced by such claims, and is being presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May).

Britain is the most obese nation in Western Europe, with rates rising faster than any other developed country. The Organisation for Economic Co-operation and Development (OECD) estimates that almost two-thirds (63%) of UK adults are overweight or obese, making the UK weight-loss market a €26 billion business. In Europe, sales of meal replacement products are estimated to reach €940 million by 2020.

'Meal replacement for weight control' products are simple, convenient and low in calories, and there is good evidence that they are an effective option for weight loss and weight maintenance. Their nutritional composition, labelling, and nutrition and health claims are governed by EU legislation which seeks to ensure that the products are nutritionally sound and that any reported benefits are clear, accurate, and based on scientific evidence.

In this study, Dr Kelly Johnston and colleagues from LighterLife and Kings College London in the UK analysed the nutrient composition, legal compliance, and consumer understanding of on-pack health and nutrition claims for all commercially available 'meal replacement for weight control' shakes sold in the UK in 2017. On-pack information was assessed for its compliance with composition, labelling, and nutrition and health claims in line with EU regulation.

The researchers found that only 10 of the brands provided enough information to demonstrate that they met all the EU compositional and labelling requirements and the majority of products did not meet the basic compositional criteria necessary to be called a 'meal replacement for weight control'.

Results also showed that more than 90% of products made at least one nutrition claim on pack and just over half made at least one health claim--yet 79% of these claims were not compliant with EU regulations. In order to gauge their understanding of on-pack nutrition and health claims, internet-based questionnaires were completed by volunteers who were currently or had recently been engaged with the LighterLife weight loss programme. Of 240 respondents (44 men), three quarters (75%) reported being on a diet within the last 6 months.

The claims most likely to be reported as being understood by responders included common weight loss messages such as "low fat" (95%), "low calorie" (95%), and "high protein" (94%). In contrast, only around half of those questioned understood the claims: "protects against chronic diseases" (48%) and "low GI" (53%) - neither of which are authorised, nor should be on pack.

Interestingly, despite a relatively high overall reported level of understanding of on-pack claims, the majority of claims were perceived as being false.

Dr Johnston concludes: "Manufacturer's misleading labelling is confusing consumers about the healthiness and nutritional quality of meal replacement shakes. Some of these claims are clearly exaggerated and many are simply untrue. What we see from this group of consumers is that they generally have false perceptions about the efficacy of such products. In other words, even if they understand the claims, they often don't believe what they are reading."

She adds: "This situation doesn't benefit anyone but what it does mean is that reputable providers are disadvantaged by unscrupulous parties who sell products not fit for purpose. This study highlights the need for better enforcement to ensure products for sale meet the legally required compositional and labelling criteria which will both protect consumers whilst ensuring fair market competition."

The authors note that they only looked at one type of product--single serve meal replacement shakes--which is not representative of the entire sector.

Credit: 
European Association for the Study of Obesity

Kaiser Permanente researchers develop new models for predicting suicide risk

Combining data from electronic health records with results from standardized depression questionnaires better predicts suicide risk in the 90 days following either mental health specialty or primary care outpatient visits, reports a team from the Mental Health Research Network, led by Kaiser Permanente research scientists.

The study, "Predicting Suicide Attempts and Suicide Death Following Outpatient Visits Using Electronic Health Records," conducted in five Kaiser Permanente regions (Colorado, Hawaii, Oregon, California and Washington), the Henry Ford Health System in Detroit, and the HealthPartners Institute in Minneapolis, was published today in the American Journal of Psychiatry.

Combining a variety of information from the past five years of people's electronic health records and answers to questionnaires, the new models predicted suicide risk more accurately than before, according to the authors. The strongest predictors include prior suicide attempts, mental health and substance use diagnoses, medical diagnoses, psychiatric medications dispensed, inpatient or emergency room care, and scores on a standardized depression questionnaire.

"We demonstrated that we can use electronic health record data in combination with other tools to accurately identify people at high risk for suicide attempt or suicide death," said first author Gregory E. Simon, MD, MPH, a Kaiser Permanente psychiatrist in Washington and a senior investigator at Kaiser Permanente Washington Health Research Institute.

In the 90 days following an office visit:

Suicide attempts and deaths among patients whose visits were in the highest 1 percent of predicted risk were 200 times more common than among those in the bottom half of predicted risk.

Patients with mental health specialty visits who had risk scores in the top 5 percent accounted for 43 percent of suicide attempts and 48 percent of suicide deaths.

Patients with primary care visits who had scores in the top 5 percent accounted for 48 percent of suicide attempts and 43 percent of suicide deaths.

This study builds on previous models in other health systems that used fewer potential predictors from patients' records. Using those models, people in the top 5 percent of risk accounted for only a quarter to a third of subsequent suicide attempts and deaths. More traditional suicide risk assessment, which relies on questionnaires or clinical interviews only, is even less accurate.

The new study involved seven large health systems serving a combined population of 8 million people in nine states. The research team examined almost 20 million visits by nearly 3 million people age 13 or older, including about 10.3 million mental health specialty visits and about 9.7 million primary care visits with mental health diagnoses. The researchers deleted information that could help identify individuals.

"It would be fair to say that the health systems in the Mental Health Research Network, which integrate care and coverage, are the best in the country for implementing suicide prevention programs," Dr. Simon said. "But we know we could do better. So several of our health systems, including Kaiser Permanente, are working to integrate prediction models into our existing processes for identifying and addressing suicide risk."

Suicide rates are increasing, with suicide accounting for nearly 45,000 deaths in the United States in 2016; 25 percent more than in 2000, according to the National Center for Health Statistics.

Other health systems can replicate this approach to risk stratification, according to Dr. Simon. Better prediction of suicide risk can inform decisions by health care providers and health systems. Such decisions include how often to follow up with patients, refer them for intensive treatment, reach out to them after missed or canceled appointments -- and whether to help them create a personal safety plan and counsel them about reducing access to means of self-harm.

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Kaiser Permanente

Hot cars can hit deadly temperatures in as little as one hour

image: Cars can become deadly after one hour in the sun on a hot summer day.

Image: 
Graphic by Safwat Saleem/ASU

A lot can happen at 160 degrees Fahrenheit: Eggs fry, salmonella bacteria dies, and human skin will suffer third-degree burns. If a car is parked in the sun on a hot summer day, its dashboard can hit 160 degrees in about an hour. One hour is also about how long it can take for a young child trapped in a car to suffer heat injury or even die from hyperthermia.

Researchers from Arizona State University and the University of California at San Diego School of Medicine have completed a study to compare how different types of cars warm up on hot days when exposed to different amounts of shade and sunlight for different periods of time. The research team also took into account how these differences would affect the body temperature of a hypothetical 2-year-old child left in a vehicle on a hot day. Their study was published May 24 in the journal Temperature.

"Our study not only quantifies temperature differences inside vehicles parked in the shade and the sun, but it also makes clear that even parking a vehicle in the shade can be lethal to a small child," said Nancy Selover, an Arizona State climatologist and research professor in ASU's School of Geographical Sciences and Urban Planning.

From January through May 2018, six children have died after being left in hot cars in the United States. That number will go up. Annually in the U.S., an average of 37 children left in hot cars die from complications of hyperthermia - when the body warms to above 104 degrees and cannot cool down. More than 50 percent of cases of a child dying in a hot car involve a parent or caregiver who forgot the child in the car.

The findings

Researchers used six vehicles for the study: Two identical silver mid-size sedans, two identical silver economy cars, and two identical silver minivans. During three hot summer days with temperatures in the 100s in Tempe, Arizona, researchers moved the cars from sunlight to shade for different periods of time throughout the day. Researchers measured interior air temperature and surface temperatures throughout different parts of the day.

"These tests replicated what might happen during a shopping trip," Selover said. "We wanted to know what the interior of each vehicle would be like after one hour, about the amount of time it would take to get groceries. I knew the temperatures would be hot, but I was surprised by the surface temperatures."

For vehicles parked in the sun during the simulated shopping trip, the average cabin temperature hit 116 degrees in one hour. Dash boards averaged 157 degrees, steering wheels 127 degrees, and seats 123 degrees in one hour.

For vehicles parked in the shade, interior temperatures were closer to 100 degrees after one hour. Dash boards averaged 118 degrees, steering wheels 107 degrees and seats 105 degrees after one hour.

The different types of vehicles tested warmed up at different rates, with the economy car warming faster than the mid-size sedan and minivan.

"We've all gone back to our cars on hot days and have been barely able to touch the steering wheel," Selover said. "But, imagine what that would be like to a child trapped in a car seat. And once you introduce a person into these hot cars, they are exhaling humidity into the air. When there is more humidity in the air, a person can't cool down by sweating because sweat won't evaporate as quickly."

Hyperthermia

A person's age, weight, existing health problems and other factors, including clothing, will affect how and when heat becomes deadly. Scientists can't predict exactly when a child will suffer a heatstroke, but most cases involve a child's core body temperature rising above 104 degrees for an extended period.

In the study, the researchers used data to model a hypothetical 2-year old boy's body temperature. The team found that a child trapped in a car in the study's conditions could reach that temperature in about an hour if a car is parked in the sun, and just under two hours if the car is parked in the shade.

"We hope these findings can be leveraged for the awareness and prevention of pediatric vehicular heatstroke and the creation and adoption of in-vehicle technology to alert parents of forgotten children," said Jennifer Vanos, lead study author and assistant professor of climate and human health at U.C. San Diego.

Hyperthermia and heatstroke effects happen along a continuum, Vanos said. Internal injuries can begin at temperatures below 104 degrees, and some heatstroke survivors live with brain and organ damage.

Why memories fail

Forgetting a child in the car can happen to anyone, said Gene Brewer, an ASU associate professor of psychology. Brewer, who was not involved in the heat study, researches memory processes, and has testified as an expert witness in a court case involving a parent whose child died in a hot car.

"Often these stories involve a distracted parent," he said. "Memory failures are remarkably powerful, and they happen to everyone. There is no difference between gender, class, personality, race or other traits. Functionally, there isn't much of a difference between forgetting your keys and forgetting your child in the car."

Most people spend a lot of time on routine behaviors, doing the same activities over and over without thinking about them. For example, driving the same route to work, taking the children to daycare on Tuesdays and Thursdays, or leaving car keys in the same spot every day. When new information comes into those routines, such as a parent's daycare drop-off day suddenly changing or an emergency phone call from a boss on the way to work, that's when memory failures can occur.

"These cognitive failures have nothing to do with the child," Brewer said. "The cognitive failure happens because someone's mind has gone to a new place, and their routine has been disrupted. They are suddenly thinking about new things, and that leads to forgetfulness. Nobody in this world has an infallible memory."

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Arizona State University

Cigarette smoke directly damages muscles in the body

image: Cigarette smoke components, whether delivered by inhalation or more directly into the circulation, negatively impact the fatigue resistance of skeletal muscle.

Image: 
Dr Leonardo Nogueira

Not only is smoking bad for your lungs, but new research shows that components in cigarette smoke directly damages your muscles. The research, published in The Journal of Physiology, indicates that smoking decreases the number of small blood vessels that bring oxygen and nutrients to muscles in the legs.

We know that smoking limits a person's ability to exercise because it makes their muscles weaker. It was widely believed this muscle weakness is because the lungs become inflamed and eventually destroyed by habitual smoking, therefore limiting activity and exercise.

However, the findings of this study suggest that cigarette smoke directly damages muscles by reducing the number of blood vessels in leg muscles, thereby reducing the amount of oxygen and nutrients they can receive. This can impact metabolism and activity levels, both of which are risk factors for many chronic diseases including chronic obstructive pulmonary disease (COPD) and diabetes.

The research conducted by the University of California, San Diego in conjunction with Universidade Federal do Rio de Janeiro and Kochi University, involved exposing mice to smoke from tobacco cigarettes for 8 weeks, either by inhalation or by injecting mice with a solution bubbled with smoke.

The study did not identify which of the approximately 4,000 chemicals in cigarette smoke are responsible for this muscle damage. Identification of the responsible chemicals is a key avenue of further research, along with understanding the process by which they reduce the number of blood vessels.

Ellen Breen, the lead investigator commented on the study:

'It is vitally important that we show people that the use of tobacco cigarettes has harmful consequences throughout the body, including large muscle groups needed for daily living, and develop strategies to stop the damage triggered by the detrimental components of cigarette smoke.'

Credit: 
The Physiological Society

Depression speeds up brain aging, find psychologists

image: This is an image of how depression and anxiety speed up cognitive ageing.

Image: 
Amber John, University of Sussex

Psychologists at the University of Sussex have found a link between depression and an acceleration of the rate at which the brain ages. Although scientists have previously reported that people with depression or anxiety have an increased risk of dementia in later life, this is the first study that provides comprehensive evidence for the effect of depression on decline in overall cognitive function (also referred to as cognitive state), in a general population.

For the study, published today, Thursday 24 May 2018, in the journal Psychological Medicine, researchers conducted a robust systematic review of 34 longitudinal studies, with the focus on the link between depression or anxiety and decline in cognitive function over time. Evidence from more than 71,000 participants was combined and reviewed. Including people who presented with symptoms of depression as well as those that were diagnosed as clinically depressed, the study looked at the rate of decline of overall cognitive state - encompassing memory loss, executive function (such as decision making) and information processing speed - in older adults.

Importantly, any studies of participants who were diagnosed with dementia at the start of study were excluded from the analysis. This was done in order to assess more broadly the impact of depression on cognitive ageing in the general population. The study found that people with depression experienced a greater decline in cognitive state in older adulthood than those without depression. As there is a long pre-clinical period of several decades before dementia may be diagnosed, the findings are important for early interventions as currently there is no cure for the disease.

Lead authors of the paper, Dr Darya Gaysina and Amber John from the EDGE (Environment, Development, Genetics and Epigenetics in Psychology and Psychiatry) Lab at the University of Sussex, are calling for greater awareness of the importance of supporting mental health to protect brain health in later life.

Dr Gaysina, a Lecturer in Psychology and EDGE Lab Lead, comments: "This study is of great importance - our populations are ageing at a rapid rate and the number of people living with decreasing cognitive abilities and dementia is expected to grow substantially over the next thirty years.

"Our findings should give the government even more reason to take mental health issues seriously and to ensure that health provisions are properly resourced. We need to protect the mental wellbeing of our older adults and to provide robust support services to those experiencing depression and anxiety in order to safeguard brain function in later life."

Researcher Amber John, who carried out this research for her PhD at the University of Sussex adds: "Depression is a common mental health problem - each year, at least 1 in 5 people in the UK experience symptoms. But people living with depression shouldn't despair - it's not inevitable that you will see a greater decline in cognitive abilities and taking preventative measures such as exercising, practicing mindfulness and undertaking recommended therapeutic treatments, such as Cognitive Behaviour Therapy, have all been shown to be helpful in supporting wellbeing, which in turn may help to protect cognitive health in older age."

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University of Sussex

Severe eczema in adults may increase risk of cardiovascular disease

Led by the London School of Hygiene & Tropical Medicine, the study examined the health records of almost 2m people in the UK. Patients with severe eczema were found to experience a 20% increased risk of stroke (389/19,622 patients with severe eczema v 21,387/1,528,477 without), 70% increased risk of heart failure (419/19,624 v 16,983/1,528,477), and 40-50% increased risk of the remaining cardiovascular outcomes, including unstable angina, myocardial infarction, atrial fibrillation and cardiovascular death, compared to patients without eczema.

Patients with eczema of any kind were 10-20% more likely to experience non-fatal cardiovascular disease than patients without eczema, but the absolute risk is low (for example, over a one year period 25 in every 10,000 patients with eczema will have heart failure, compared to 21 in every 10,000 people without eczema).

Eczema can vary over time and patients whose eczema was active for most of their follow up were also at greater risk of cardiovascular outcomes. The risk was mainly confined to patients with severe eczema, including people on oral immunosuppressive drugs, those receiving phototherapy treatment for eczema or who were referred to dermatologists.

Although this observational study can't show cause and effect, cardiovascular prevention strategies among patients with severe and predominantly active eczema should be considered if findings are replicated by future studies.

Eczema, also known as atopic eczema or atopic dermatitis, is a common systemic inflammatory skin condition which affects up to 10% of adults in the UK and is becoming more common globally. Of those with eczema, 30% have moderate to severe disease with approximately 5% having severe disease. Symptoms include intense itch, pain and sleeplessness.

Dr Sinead Langan, Wellcome Trust Senior Fellow at the London School of Hygiene & Tropical Medicine and study lead investigator, said: "Eczema is a debilitating common condition. Increasing evidence suggests that severe eczema could be associated with a wider range of health problems than originally thought. Previous studies on the link between eczema and cardiovascular disease have reported mixed findings. However, these have lacked data on specific risk factors and have not assessed levels of eczema activity over time, points which our research addressed."

Using UK electronic health records from the Clinical Practice Research Datalink, Hospital Episode Statistics and data from the Office for National Statistics between 1998 and 2015, the researchers matched patients diagnosed with eczema and those without eczema on age, gender, general practice and calendar time. After adjusting for confounders such as socioeconomic status and age, the researchers examined the differences in cardiovascular disease risk between the two groups. Risks in severe eczema persisted after taking into account known cardiovascular risk factors, such as weight (BMI), smoking and alcohol intake.

Dr Langan said: "We found that severe eczema was linked with an increased risk of not only stroke and heart failure, but also a 30-40% increased risk of unstable angina, myocardial infarction, atrial fibrillation and cardiovascular death. Patients experiencing very severe eczema and those with symptoms the majority of the time were most at risk.

"It's important to highlight the absolute risk of people with eczema experiencing a cardiovascular event is low. However, with heart and circulatory disease causing more than a quarter of all deaths in the UK, it's important we explore all potential risk factors.

The links uncovered in our research, if robustly replicated by future studies, would support targeted screening and focus on primary prevention strategies to reduce cardiovascular disease among patients with eczema."

The authors acknowledge limitations of their study, including misclassification of eczema disease severity, though this is likely to have led to underestimation of the true associations. It is also not possible to completely disentangle the effects of eczema therapy and disease severity.

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London School of Hygiene & Tropical Medicine

Study finds antioxidant-enriched vitamin reduces respiratory illnesses in patients with CF

Researchers at Children's Hospital Colorado (Children's Colorado) and the University of Colorado School of Medicine have found that taking a specially formulated antioxidant-enriched multivitamin may decrease respiratory illnesses in people with cystic fibrosis (CF).

The study, which was recently published online in the American Journal of Respiratory and Critical Care Medicine, looked at the effects of a 'cocktail' of multiple antioxidants on inflammation and health outcomes in patients with CF. Inflammation is an important contributor to lung damage in CF, and contributes to progressive lung function decline.

The 16-week study consisted of 73 pancreatic-insufficient CF patients ages 10 years and older (average age 22 years). These patients ordinarily do not adequately absorb important dietary antioxidants including carotenoids such as beta(β)-carotene, tocopherols (vitamin E), coenzyme Q10 (CoQ10), and selenium that help to neutralize inflammation in the body. To address this issue, the antioxidants used in the study were delivered in a capsule specifically designed for individuals with difficulties absorbing fats and proteins, including those with CF.

Antioxidant supplementation was safe and well-tolerated. Supplemental antioxidants increased antioxidant concentrations in the bloodstream in treated subjects and temporarily reduced inflammation in the blood at four weeks but not 16 weeks. Importantly, antioxidant treatment appeared to both prolong the time to the first respiratory illness requiring antibiotics and reduce the frequency of respiratory illnesses they experienced.

Specifically, half as many of the patients taking the supplemental antioxidants experienced a pulmonary exacerbation (or respiratory illness) requiring antibiotics compared to the group taking the control multivitamin without added antioxidants at 16 weeks. In addition, the antioxidant treated group experienced a lower frequency of respiratory illnesses compared to the control group.

"Single oral antioxidant formulations have been previously tested in CF with mixed results. However, there had not been a well-designed, randomized controlled trial of an antioxidant 'cocktail' that included multiple antioxidants in a single formulation," said Scott D. Sagel, MD, PhD, pediatric pulmonologist at Children's Colorado and professor of pediatrics at the University of Colorado School of Medicine. "While more research certainly needs to be done to find a treatment that delivers a sustained anti-inflammatory effect, we believe the fact that this antioxidant supplement prolonged the time patients had before their first illness is meaningful. It offers a simple, relatively inexpensive means for restoring and maintaining normal antioxidant levels in people who would otherwise have trouble doing so."

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Children's Hospital Colorado

Space-like gravity weakens biochemical signals in muscle formation

image: These are skeletal myoblast cells in rats.

Image: 
Yuge Lab

Astronauts go through many physiological changes during their time in spaceflight, including lower muscle mass and slower muscle development. Similar symptoms can occur in the muscles of people on Earth's surface, too. In fact, it could affect everyone to some extent later in life.

"Age-related skeletal muscle disorders, such as sarcopenia, are becoming a greater concern in society," said Hiroshima University (HU) Professor and Space Bio-Laboratories Director Louis Yuge. "It is especially a big concern in Japan, where the number of aging people is increasing."

In a study published in Microgravity, a medical research group at HU led by Yuge shed light on these similarities. They found that the process that affects gene expression of differentiating muscle cells in space also affects cells in the presence of gravity.

The genetic and molecular basis of impaired muscle development has been unclear. Yuge thinks there is a pressing need to understand it and come up with better treatment outcomes.

He and his team investigated how simulated microgravity - that is, gravity in space-like conditions - affects muscle cell differentiation and gene expression.

They observed what happened to rat muscle cells over time. Some cells were treated with a drug that stops DNA methylation from happening, while other cells were not. DNA methylation is a process that controls gene expression and muscle cell differentiation.

Next, they grew the cells either in normal gravity or inside of Gravite, a machine that simulates gravity at levels that astronauts experience in spaceflight. Cells in microgravity exhibited less cell differentiation after all. However, cells growing without the drug formed muscle fibers at a slower rate and showed less gene expression.

One gene, Myod1, was of particular interest. Its expression levels were significantly lower in microgravity conditions and when growing with the drug that stopped DNA methylation.

Within gravity, as well as without it, the group concluded that DNA methylation appears to be a key player in regulating muscle cell differentiation. "These findings highlight genes affected by DNA methylation, like Myod1, as potential targets for treating patients with skeletal muscle atrophy," Yuge said.

The team's results can be utilized in space experiments, where muscle atrophy of astronauts uses myotubes because it is easy to understand morphologically. Additionally, the findings of this epigenetics can be used in many differentiated cells, stem cells, or cancer. The Micro-G Center of the Kennedy Space Center of NASA, where Yuge is an advisory committee member, and NASA have already conducted experiments to cultivate stem cells on the International Space Station, where this paper can also provide insight. Yuge and his team are expected to start a massive space experiment at NASA/Center for Advancement of Science in Space (CASIS).

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Hiroshima University

The Trump Presidency's impact on public perception of the Republican Party

A new Presidential Studies Quarterly article analyzes the effects of the early Trump Presidency on public attitudes toward the Republican Party.

Survey data indicate that Trump appears to be widening the demographic and cultural differences between ordinary Republicans and Democrats, exacerbating the gender, age, and racial gaps between the party coalitions in a way that threatens the long-term vitality of his party.

"Polls suggest that if his approval ratings remain at or below 40 percent, as they have through the first quarter of 2018, Democrats have excellent prospects for winning control of the House," said author Prof. Gary Jacobson, of the University of California, San Diego.

Credit: 
Wiley

First chip-scale broadband optical system that can sense molecules in the mid-IR

image: This is a schematic of silicon microresonator generating a frequency comb that samples molecules for chemical identification.

Image: 
Alexander Gaeta/Columbia Engineering

Researchers at Columbia Engineering have demonstrated, for the first time, a chip-based dual-comb spectrometer in the mid-infrared range, that requires no moving parts and can acquire spectra in less than 2 microseconds. The system, which consists of two mutually coherent, low-noise, microresonator-based frequency combs spanning 2600 nm to 4100 nm, could lead to the development of a spectroscopy lab-on-a-chip for real-time sensing on the nanosecond time scale.

"Our results show the broadest optical bandwidth demonstrated for dual-comb spectroscopy on an integrated platform," said Alexander Gaeta, David M. Rickey Professor of Applied Physics and of Materials Science and senior author of the study, published May 14 in Nature Communications.

Creating a spectroscopic sensing device on a chip that can realize real-time, high-throughput detection of trace molecules has been challenging. A few months ago, teams led by Gaeta and Michal Lipson, Higgins Professor of Electrical Engineering, were the first to miniaturize dual-frequency combs by putting two frequency comb generators on a single millimeter-sized chip. They have been working on broadening the frequency span of the dual combs, and on increasing the resolution of the spectrometer by tuning the lines of the comb.

In this current study, the researchers focused on the mid-infrared (mid-IR) range, which, because its strong molecular absorption is typically 10 to 1,000 times greater than those in the visible or near-infrared, is ideal for detecting trace molecules. The mid-IR range effectively covers the "fingerprint" of many molecules.

The team performed mid-IR dual-comb spectroscopy using two silicon nanophotonic devices as microresonators. Their integrated devices enabled the direct generation of broadband mid-infrared light and fast acquisition speeds for characterizing molecular absorption.

"Our work is a critical advance for chip-based dual-comb spectroscopy for liquid/solid phase studies," said Mengjie Yu, lead author of the paper and a PhD student in Gaeta's lab. "Our chip-scale broadband optical system, essentially a photonic lab-on-a-chip, is well-suited for identification of chemical species and could find a wide range of applications in chemistry, biomedicine, material science, and industrial process control."

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Columbia University School of Engineering and Applied Science

Disadvantaged students with lower grades do just as well on medical degrees

Students from some of England's worst performing secondary schools who enroll on medical degrees with lower A Level grades, on average, do at least as well as their peers from top performing schools, a new study has revealed.

The research also found that students from poorly performing schools who match the top A Level grades achieved by pupils from the best performing schools, go on to do better during a medical degree.

The authors of the research are now calling for medical school entry criteria to be relaxed for all pupils applying from low-performing schools.

The study, led by academics from the University of York alongside partners at the Universities of Dundee and Durham, analysed data from UK medical degree courses and linked it to information on secondary schools from the Department for Education.

Some universities, such as Birmingham, Southampton and Kings College London, have already trialled A Level 'grade discounting' for medical school place offers for some disadvantaged applicants.

Lead author of the paper, Lazaro Mwandigha, from the Department of Health Sciences at the University of York said: "This study suggests that relaxing A Level grade entry requirements for students from the worst performing secondary schools is beneficial. Although there are important further questions about how to fairly classify schools, the study demonstrates that these students are, on average, just as able to keep up with the pace of a medical degree".

There is fierce competition to study medicine in the UK with normally around 11-12 applications made for each place on offer. Partly as a result of this, entry grade requirements have crept up to AAA or A* AA at A Level. Despite only 5.3% of children in the UK going to private school, around half of medical degree places are currently filled by students who attended selective schools.

Supervising author Dr Paul Tiffin said: "This study is the first robust evidence that grade discounting for pupils from underperforming schools is justified. At the moment around 20% of UK schools are providing 80% of our medical students so A Level achievement should be viewed in terms of the context in which a pupil learns in order to help increase fairness and widen participation in medicine."

While they acknowledge it is not a "cure all" solution, the researchers argue that lowering entry grades for certain pupils could work as part of a package of measures.

Dr Lewis Paton, another member of the research team at the University of York, said: "Bright pupils from less well performing schools sometimes don't apply to medical school because they or their teachers don't think they'll make the grades required to get in. If medical schools started to contextualise A Level results, it could make access to studying medicine appear more achievable."

The researchers argue that widening access to medical degrees is not just a matter of social fairness; it is also something that would benefit the UK's health services.

Dr Tiffin added, "The NHS needs more doctors from under-represented minority groups. Having doctors from a wider range of backgrounds would enable health professionals to better understand and meet the UK's diverse healthcare needs."

Clare Owen, Assistant Director of the Medical Schools Council, said "This research adds important data to our understanding of how entry requirements relate to subsequent performance. The Medical Schools Council recognises the benefits of admissions which take applicants' backgrounds into account and this year published a guide which collects together the best practice of medical schools as they implement contextual admissions. Each medical school must decide on the best approach for its circumstances and this research will help them by making a significant contribution to the evidence base"

The study looked at data on medical students who had taken the UK Clinical Aptitude Test (UKCAT) - the admissions test used by most UK universities for admissions to their medical degree programmes. The dataset included information on schools attended by applicants, A level results, admissions to medical degrees and performance on the course.

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University of York

CU researchers offer insights into liver disease caused by intravenous nutrition

AURORA, Colo. (May 23, 2018) - Research by physician-scientists at the University of Colorado Anschutz Medical Campus offers hope for improved quality of life for people who rely on intravenous nutrition due to intestinal damage.

Karim C. El Kasmi, MD, PhD, assistant professor of pediatrics, and Ronald Sokol, MD, professor of pediatrics, are authors of an article in the April 2018 Nature Communications that sheds light on the underlying cause of intestinal failure-associated liver disease and suggests new therapeutic approaches.

Intestinal failure is a condition that occurs when a person's intestines are injured, damaged, or surgically shortened resulting in the need for the person to receive daily intravenous (IV) nutrition to sustain health. This IV nutrition, called parenteral nutrition, can be given in the hospital or at home through semi-permanent IV catheters.

Side effects of this form of nutrition are jaundice, liver injury called cholestasis, and eventually scarring in the liver. Intestinal failure-associated liver disease could eventually become so severe that the person would need a liver transplant or a combined liver and intestinal transplant to survive.

Until recently, there has been no effective therapy because of a poor understanding of how intestinal failure related to the development of the liver disease. Over the past decade, investigators have learned that reducing or changing the IV lipids can have a beneficial effect on some, but not all, patients.

Drs. El Kasmi and Sokol developed a mouse model that mimics the situation in humans with intestinal failure who depend on IV nutrition. Mice with intestinal injury that are given PN through a central venous catheter for 7 to 28 days develop decreased liver function, called cholestasis, and liver injury.

The researchers were able to show that products from bacteria in the intestine of the mice, called lipopolysaccharides (LPS), are absorbed through the injured intestine and activate the immune system in the liver to produce a cytokine, IL-1 beta, leading to cholestasis. The combination of IV lipids and intestinal injury lead to the intestinal failure-associated disease.

With this understanding, the researchers identified three possible new targets for drug intervention to prevent or treat intestinal failure-associated disease. Several drugs that target these disease-causing pathways are already approved or in development. Further testing in clinical trials with affected patients is required, but this research opens the possibility of treating patients who need long-term IV nutrition without the worry of developing serious liver damage.

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University of Colorado Anschutz Medical Campus

Leg exercise is critical to brain and nervous system health

Groundbreaking research shows that neurological health depends as much on signals sent by the body's large, leg muscles to the brain as it does on directives from the brain to the muscles. Published today in Frontiers in Neuroscience, the study fundamentally alters brain and nervous system medicine -- giving doctors new clues as to why patients with motor neuron disease, multiple sclerosis, spinal muscular atrophy and other neurological diseases often rapidly decline when their movement becomes limited.

"Our study supports the notion that people who are unable to do load-bearing exercises -- such as patients who are bed-ridden, or even astronauts on extended travel -- not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted," says Dr. Raffaella Adami from the Università degli Studi di Milano, Italy.

The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.

Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes -- specialized cells that support and insulate nerve cells -- didn't fully mature when exercise was severely reduced.

The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. Cutting back on exercise makes it difficult for the body to produce new nerve cells -- some of the very building blocks that allow us to handle stress and adapt to challenge in our lives.

"It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things," says Adami. "Neurological health is not a one-way street with the brain telling the muscles 'lift,' 'walk,' and so on."

The researchers gained more insight by analyzing individual cells. They found that restricting exercise lowers the amount of oxygen in the body, which creates an anaerobic environment and alters metabolism. Reducing exercise also seems to impact two genes, one of which, CDK5Rap1, is very important for the health of mitochondria -- the cellular powerhouse that releases energy the body can then use. This represents another feedback loop.

These results shed light on several important health issues, ranging from concerns about cardio-vascular impacts as a result of sedentary lifestyles to insight into devastating diseases, such as spinal muscular atrophy (SMA), multiple sclerosis, and motor neuron disease, among others.

"I have been interested in neurological diseases since 2004," says co-author Dr. Daniele Bottai, also from the Università degli Studi di Milano. "The question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?"

This research demonstrates the critical role of movement and has a range of potential implications. For example, missions to send astronauts into space for months or even years should keep in mind that gravity and load-bearing exercise play an important role in maintaining human health, say the researchers.

"One could say our health is grounded on Earth in ways we are just beginning to understand," concludes Bottai.

Credit: 
Frontiers

Lightening up dark galaxies

image: One of the new dark-galaxy candidates, identified through a combination of spectral information (left) and images reflecting the emission of gas (middle) and stars (right). The position of the dark-galaxy candidate is marked by the red circle.

Image: 
R. A. Marino / MUSE

Despite substantial progress over the past half a century in understanding of how galaxies form, important open questions remain regarding how precisely the diffuse gas known as the 'intergalactic medium' is converted into stars. One possibility, suggested in recent theoretical models, is that the early phase of galaxy formation involves an epoch when galaxies contain a great amount of gas but are still inefficient at forming stars. Direct proof of such a 'Dark Phase' has been so far elusive, however --- after all, dark galaxies do not emit much visible light. The observational discovery of such galaxies would therefore fill an important gap in our understanding of galaxy evolution.

There are ways to bring dark galaxies to lighten up though. An international team led by Dr. Raffaella Anna Marino and Prof. Sebastiano Cantalupo from the Department of Physics at ETH Zurich has now done just that and thus was able to search the sky for potential dark galaxies with unprecedented efficiency. And successfully so, as they report in a paper published today in The Astrophysical Journal: they have identified at least six strong candidates for dark galaxies.

To overcome the obstacle that their target objects are dark, the team used a flashlight of sorts, which came in the form of quasars. These emit intense ultraviolet light, which in turn induces fluorescent emission in hydrogen atoms known as the Lyman-alpha line. As a result, the signal from any dark galaxies in the vicinity of the quasar gets a boost, making them visible. Such 'fluorescent illumination' has been used before in searches for dark galaxies, but Marino et al. now looked at the neighbourhood of quasars at greater distances than has been possible in earlier observations.

Also, they acquired the full spectral information for each of the dark-galaxy candidates. Deep observations --- 10 hours for each of the six quasar fields they studied --- enabled Marino and her colleagues to efficiently tell dark-galaxy candidates apart from other sources. From initially 200 Lyman-alpha emitters, half a dozen regions remained that are unlikely to be normal star-forming stellar populations, making them robust candidates for dark galaxies.

The advances in observational capability have become possible thanks to the Multi Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT) of the European Southern Observatory (ESO) in Chile. In essence, previous studies were limited to imaging a relative narrow band of frequencies, for which specific filters had to be designed. The MUSE instrument instead allowed hunting 'blindly' -- without filters -- for dark galaxies around quasars at larger distances from Earth than had been possible so far.

Credit: 
ETH Zurich Department of Physics

Cheeseburger or salad? How music volume impacts your decision

TAMPA, Fla. (May 23, 2018)- Music can be the ultimate mood setter. Faster beats ignite excitement, while slower songs help one relax. And that makes all the difference in what we order from restaurant menus.

A study published in the Journal of the Academy of Marketing Sciences finds the volume of ambient music has a systemic effect on consumers' preferences for healthy vs. non-healthy foods. That's because volume is proven to directly impact heart rate and arousal. Softer music has a calming effect, making us more mindful of what we order. This typically results in healthier choices, such as a salad. Louder environments increase stimulation and stress, inspiring diners to crave a greasy cheeseburger and fries instead.

"Restaurants and supermarkets can use ambient music strategically to influence consumer buying behavior," said Dipayan Biswas, PhD, marketing professor at the University of South Florida Muma College of Business."

Dr. Biswas conducted the study at a café in Stockholm, Sweden, which played various genres of music in a loop separately at 55Db and 70Db. The menu items were coded as healthy, non-healthy and neutral, the category used for items like coffee or tea. During the experiment conducted over several hours across multiple days, researchers found 20% more restaurant patrons ordered something unhealthy when exposed to louder ambient music compared to those who dined during a quieter time.

55Db (295 items sold)    70Db (254 items sold)

Healthy- 32%     Healthy- 25%

Non-healthy- 42%     Non-healthy- 52%

Neutral- 26%     Neutral- 23%

While previous studies have looked at varying aspects of ambience's impact on food sales such as lighting, scent and décor, this is the first study to look specifically at how volume dictates healthy vs. non-healthy food choices. These findings allow restaurant managers to strategically manipulate music volume to influence sales.

Credit: 
University of South Florida (USF Health)