Tech

WASHINGTON, D.C., December 10, 2019 - Thrips are tiny insects 2 millimeters long, about as long as four human hairs are thick. Thrips are known for their unwelcome ability to devour garden plants and, lately, to inform the design of microrobotics.

Unlike larger insects, birds, and airplanes, thrips don't rely on lift in order to fly. Instead, the tiny insects rely on a drag-based flight mechanism, keeping themselves afloat in airflow velocities with a large ratio of force to wing size. Wind is proportionally stronger when you are a tiny insect with wings that measure on the microscale.

The leading-edge vortex is remarkably defused at such a tiny size, so little lift force can be generated. Author Yonggang Jiang explained the cause of this is the ultralow Reynolds number, which is a ratio between inertial and viscous forces in a fluid, such as the air.

While model-based studies have confirmed a drag-based mechanism for tiny insects, models aren't biologically faithful. A thrip's wing can have between 45 and 120 hairlike bristles extending from the wing membrane.

Despite the increasing precision of microelectromechanical systems, prior studies risked inaccurate calculations of drag force, because they did not include the length, angle or number of bristles.

In a study published this week in the Journal of Applied Physics, from AIP Publishing, researchers performed the first test of the drag force on an actual thrip's wing under constant airflow in a bench-top wind tunnel. Drawing from experience in microfabrication and nanomechanics, Jiang created an experiment in which a thrip's wing was glued to a self-sensing microcantilever that uses piezoresistors to take voltage measurements that are used to calculate the drag force on the wing.

The study served to quantify the aerodynamic characteristics of the wings, closely examining how much air leaks through the bristled wing and how airflow leakiness affects the drag force per unit area. The natural bristled design could be useful in designing tiny flying or swimming robots, Jiang said, as well as flow sensors and gas sensors, in which a bristled structure could increase sensitivity.

The authors plan to further explore using a microcantilever to study the thrip's flight mechanism and the kinematics of the wing, including the angle of attack, the various angles at which a thrip can position its wing, and how that affects the drag force in flight.

Researchers have found that transfusions using fresh red blood cells--cells that have spent seven days or less in storage--are no more beneficial than older red blood cells in reducing the risk of organ failure or death in critically ill children. The findings, the researchers said, should reassure doctors that the standard practice of using older red cells is just as safe and effective in these children, who are among the sickest and most fragile of patients.

The study, one of the largest clinical trials to investigate red blood cell storage in critically ill children, sheds light on a controversial aspect of transfusion medicine that has been understudied. It was funded in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, and the findings will appear online on Dec. 10 in the Journal of the American Medical Association.

"Our findings indicate that doctors should not be afraid to use older red cells in critically ill children," said study co-principal investigator Philip Spinella, M.D., a researcher with the Pediatric Critical Care Translational Research Program at Washington University School of Medicine in St. Louis. "Those who are showing a preference for fresh red cells might consider discontinuing this practice unless there are extenuating circumstances." Spinella added that the findings also provide good news for blood banks, which he said will likely feel less pressure to respond to requests for fresh red cells.

Red blood cell transfusions are commonly given to critically ill children for conditions such as trauma, cancer chemotherapy, intraoperative bleeding, and chronic conditions such as sickle cell disease and thalassemia. Transfusing the oldest red cells in the stored inventory first is standard practice among many hospitals. However, some hospitals preferentially give fresh red blood cells to critically ill children, even though clinical studies supporting the benefits of this practice have been lacking.

To help fill the research gap, scientists conducted the Age of Blood in Children in Pediatric Intensive Care Units (ABC-PICU) randomized trial at 50 medical centers between February 2014 and November 2018. They recruited critically ill patients from pediatric intensive care units in the United States, Canada, France, Italy, and Israel.

For the primary analysis, the researchers included a group of 1,461 critically ill children, half boys and half girls, between 3 days old and 16 years old. Half of the patients received transfusions with fresh red blood cells stored for less than seven days and half received transfusions with older, moderately aged red cells stored for 12 to 25 days. The researchers then measured the development of new or progressive multiorgan dysfunction (impairment of one or more organs) for 28 days or until the patients were discharged from the hospital or died.

The researchers found that fresh red cells did not reduce the incidence of new or progressive multiple organ dysfunction or death compared to older red cells and that the outcomes were not significantly different between the two groups. About 20.2% of those who received fresh red cells experienced new or progressive organ dysfunction while 18.2% of those who received older red cells experienced similar dysfunction.

Marisa Tucci, M.D., a co-principal investigator for the study and a researcher at the University of Montreal, noted that the study's relatively large size and geographic diversity were among its strengths, making it reasonable for researchers to generalize to the larger pediatric population.

The researchers did note some caveats. The study did not examine whether the use of the oldest red cells allowable (35-42 days old) affects outcomes, or if fresh red cells affect outcomes for children requiring large-volume red cell transfusions. The children in this study received low-volume red cell transfusions.

"The results of this study and other studies suggest that future research should be focused on deeper characterization of red blood cell products. This will help optimize the safety and effectiveness of these products among children, as well as others," said Traci Mondoro, Ph.D., the NHLBI project officer for the study. Mondoro, who also is chief of the Translational Blood Science and Resources Branch in the NHLBI Division of Blood Diseases and Resources, added that becoming a blood donor can help advance this kind of research--and save lives, too.

New research strongly suggests that the distinct 'oxygenation events' that created Earth's breathable atmosphere happened spontaneously, rather than being a consequence of biological or tectonic revolutions.

The University of Leeds study, published in the journal Science, not only shines a light on the history of oxygen on our planet, it gives new insight into the prevalence of oxygenated worlds other than our own.

The early Earth had no oxygen in its atmosphere or oceans until roughly 2.4 billion years ago when the first of three major oxygenation events occurred. The reasons for these 'stepwise' increases of oxygen on Earth have been the subject of ongoing scientific debate.

In a new study, Leeds researchers modified a well-established conceptual model of marine biogeochemistry so that it could be run over the whole of Earth history, and found that it produced the three oxygenation events all by itself.

Their findings suggest that beyond early photosynthetic microbes and the initiation of plate tectonics - both of which were established by around three billion years ago - it was simply a matter of time before oxygen would reach the necessary level to support complex life.

This new theory drastically increases the possibility of high-oxygen worlds existing elsewhere.

Study lead author Lewis Alcott, a postgraduate researcher in the School of Earth and Environment at Leeds, said: "This research really tests our understanding of how the Earth became oxygen rich, and thus became able to support intelligent life.

"Based on this work, it seems that oxygenated planets may be much more common than previously thought, because they do not require multiple - and very unlikely - biological advances, or chance happenings of tectonics."

The first "Great Oxidation Event" occurred during the Paleoproterozoic era - roughly 2.4 billion years ago. The subsequent wholesale oxygenation events occurred in the Neoproterozoic era around 800 million years ago and finally in the Paleozoic Era roughly 450 million years ago, when atmospheric oxygen rose to present day levels.

Large animals with high energy demands require high levels of oxygen, and evolved soon after the last of these steps, ultimately evolving into dinosaurs and mammals.

Currently, the two prevailing theories suggest the drivers of these oxygenation events were either major steps in biological revolutions - where the evolution of progressively more complex lifeforms essentially "bioengineered" oxygenation to higher levels - or tectonic revolutions - where oxygen rose due to shifts in the style of volcanism or make-up of the crust.

The new study instead highlights a set of feedbacks that exist between the global phosphorus, carbon and oxygen cycles, which are capable of driving rapid shifts in ocean and atmospheric oxygen levels without requiring any 'stepwise' change in either tectonics or biology.

Study co-author Professor Simon Poulton, also from the School of Earth and Environment at Leeds said: "Our model suggests that oxygenation of the Earth to a level that can sustain complex life was inevitable, once the microbes that produce oxygen had evolved."

Their 'Earth system' model of the feedbacks reproduces the observed three-step oxygenation pattern when driven solely by a gradual shift from reducing to oxidizing surface conditions over time. The transitions are driven by the way the marine phosphorus cycle responds to changing oxygen levels, and how this impacts photosynthesis, which requires phosphorus.

Senior author Dr Benjamin Mills, who leads the biogeochemical modelling group at Leeds, said: "The model demonstrates that a gradual oxygenation of Earth's surface over time should result in distinct oxygenation events in the atmosphere and oceans, comparable to those seen in the geological record.

"Our work shows that the relationship between the global phosphorus, carbon and oxygen cycles is fundamental to understanding the oxygenation history of the Earth. This could help us to better understand how a planet other than our own may become habitable."

As the cut flower industry hits one of its busiest periods, new research has shown that the water-absorbing green floral foam used by florists is contributing to the world's microplastic problem.

A study by RMIT University published in Science of the Total Environment found the plastic foam, which breaks into tiny pieces, can be ingested by a range of freshwater and marine animals and affect their health.

Charlene Trestrail from RMIT's Ecotoxicology Research group said the study - the first to examine the environmental effects of foam - looked specifically at the impact of this widely-used substance on aquatic animals.

"We tested a range of invertebrates with different feeding modes and all animals ingested the foam, with some species demonstrating stress responses as a result of consuming the material," said Trestrail, a PhD researcher in the School of Science.

The vast majority of florists who use foam are disposing of floral foam particles down the sink, according to a recent survey by the Sustainable Floristry Network.

The survey of more than 1200 florists globally found two-thirds of florists use foam, and of those that do, 72% pour the foam wastewater down the sink or drain, while 15% add it to the garden or soil.

A social media trend of crushing floral foam, often directly into the sink, is also adding to floral foam pollution issues, with one video promoting the fad amassing 70 million views. Each foam block is equivalent in weight to around 10 plastic bags.

Rita Feldmann, Founder of the Sustainable Floristry Network, said the research confirms the suspicions of concerned florists who are questioning the product and reverting to more sustainable, old-fashioned methods of floral design.

"For an industry that seeks to celebrate nature, we are actually adding to environmental problems when using this product," Feldmann said.

"Disposal issues have stemmed directly from a lack of user information about the product on packaging and at the point of sale.

"For the past 60 years, florists all over the world have been pouring it down the sink or putting it in the soil. And we have no idea what customers do with it - we do know that it is regularly buried with coffins."

Fighting against floral foam

Floral foam has been the base medium of choice for florists all over the world since its invention in the US by manufacturer Smithers Oasis in the 1950s.

The RMIT study showed the floral foam microplastics also leach chemicals into the surrounding water and these were more toxic to aquatic invertebrates than leachates from other plastic families.

Trestrail said more research was needed to better understand the impact of ingestion of the particles and related compounds on animals.

New global organisation the Sustainable Floristry Network has been created on the back of the #nofloralfoam movement started by Feldmann, with many florists among the 33,000 following the @nofloralfoam Instagram account.

Backed by highly regarded florists from around the globe, the Sustainable Floristry Network aims to support florists to transition to more sustainable practices by providing free education on foam-free floristry and sustainable floral design and business practices.

The network will also provide a guide for how customers can find a sustainable florist.

The picture of sea otters frolicking among kelp beds and rocky shoals has become an iconic image of the California coastline. But it may be drawing attention away from the value of other habitat that could truly help the endangered species in its recovery - estuaries.

In fact, a new study released today concludes that California could more than triple its population of southern sea otters, from an estimated 3,000 to nearly 10,000, by repopulating the largest estuary on the coast - the San Francisco Bay.

"It would essentially end up lifting the sea otter out of its endangered species status," said Brent Hughes, assistant professor of biology at Sonoma State and lead researcher in the study published in PeerJ. "For the conservation of the sea otter, this would be huge."

According to Hughes and fellow researchers, current southern sea otter recovery plans have not included estuaries as target habitats. This "may be an artifact of where the surviving population persisted," they concluded in their paper titled "Species recovery and recolonization of past habitats: Lessons for science and conservation from sea otters in estuaries."

"Sea otters are widely associated with kelp forests in the minds of both the scientific community and the general public," said Lisa Needles, a member of the research team based at California Polytechnic State University. "However, over the last two decades, we've seen the resurgence of sea otters in two estuaries, Morro Bay and Elkhorn Slough. This led us to realize that not only did they occur in estuaries in large numbers in the past but they're also integral to the ecosystem health of estuaries, just as they are in kelp forests."

The southern sea otter was widely believed to be extinct due to the expansive fur trade of the 18th and 19th centuries, which reduced the global population from between 150,000 and 300,000 to roughly 2,000. Then in 1914 a remnant population of about 50 southern sea otters was found along the rugged Big Sur shoreline. Thanks to conservation efforts, the population has since grown to more than 3,000, but their numbers are still far below their historic numbers and range.

While conservation efforts have focused on protecting otters in these rocky coastal habitats, evidence shows that southern sea otters were once abundant in California estuaries, including in San Francisco Bay. Early accounts by Spanish explorers noted otter populations as far south as San Jose and as far north as Richardson Bay. "Sea otters probably numbered in the thousands in this estuary prior to being driven to local extinction by over-hunting," the researchers noted.

The only estuary in California that is currently home to a distinct and self-sustaining population of sea otters is Elkhorn Slough at Moss Landing in Monterey Bay. Overall, southern sea otters have only recolonized about 13 percent of their historic range, according to the study.

Hughes says one of the reasons otter habitat has remained fragmented and why sea otters have not been able to migrate north and reestablish residency in San Francisco Bay is the presence of great white sharks near the Golden Gate. "We call it 'the gauntlet,' " said Hughes. "Otters really can't get past the gauntlet."

But if otter populations were established inside San Francisco Bay and out of the range of great whites they would become the top predator and would likely thrive.

Using existing studies and modeling of sea otter growth, the researchers concluded that the San Francisco Bay could support about 6,600 sea otters, more than twice the current estimated population of 3,000. "It would change the game in terms of how we look at sea otter conservation," he said.

Snowstorms can wreak havoc across the United States, but especially on the East Coast. Snow is the least-understood form of precipitation, with major snowstorms among the most difficult weather events to forecast. Yet people rely on these forecasts to stay safe, plan travel routes and decide whether to close schools or businesses.

To better understand large, disruptive snowstorms, a University of Washington atmospheric scientist will lead a NASA field campaign this winter to fly through major snowstorms along the East Coast. The multi-institutional team will observe snow as it forms in clouds to help with satellite monitoring of snowfall and ultimately improve forecasts.

"In a big snowstorm, the snow is not evenly distributed. Some places really get hammered, but others, even close by, don't get nearly as much. We want to understand the processes behind that," said principal investigator Lynn McMurdie, a UW research associate professor of atmospheric sciences.

The NASA Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Storms, or IMPACTS campaign, will be based at NASA's Wallops Flight Facility on the Virginia coast. The six-week campaign runs Jan. 15 through late February 2020, with additional campaigns in the same region in the winters of 2021 and 2022.

"Winter clouds contain regions that generate more snow, called snow bands," McMurdie said. "We hope to understand why these snow bands form, and how they evolve with the developing storm. If we can understand the processes in the clouds, we can better predict how they distribute snowfall to us on the ground."

IMPACTS is the first field campaign to study East Coast snowstorms in 30 years, and the most comprehensive study of Northeast snowstorms to date.

McMurdie led a previous NASA field campaign in 2015 that measured rain and snow over Washington state's Olympic Peninsula. That effort focused mostly on rain over mountainous terrain; this one will focus on snow, and over relatively flatter terrain. On the Eastern Seaboard, the combination of cold air from Canada and moisture from the Atlantic Ocean can produce major snowstorms that stretch from Georgia to Maine.

"Over the course of three years, we need at least six good storms," McMurdie said. "We expect far more, but they might not be good storms. And we want some redundancy to make sure we have all the instruments working during those events and to sample of a variety of storm intensities."

Two aircraft will collect observations. One is the high-flying ER-2 that flies at 20 kilometers (12 miles) altitude. A single specialized pilot wears a spacesuit and carries oxygen, and the plane's broad wings let it fly through thinner air. That aircraft will collect large-scale observations from above the clouds.

"The instruments on the ER-2 will be the same as the ones flown on satellites," McMurdie said. "But the airplane is closer to Earth and we can tell it where to go, so we can sample regions over and over again."

The second aircraft is a P-3 research aircraft that will travel through the clouds, lower than commercial planes, for a bumpier flight that offers a close-up view of snow particles. Instruments on board will monitor exactly what types of snow is forming and falling from the clouds. The P-3 will also drop balloons over the ocean that carry a box of instruments to measure temperature, humidity and winds.

Snow is a challenge to detect from space because satellite models assume that the snow crystal is a simple geometrical shape, which isn't realistic. The most famous form of snow, snowflakes, are especially tricky to image from space. The lower aircraft includes instruments that can image individual flakes from two angles, to capture them head-on and in profile.

"Snow can be hundreds of different shapes, which is not easy to do mathematically," McMurdie said. "The geometry alone is enough to put you through a tizzy. To assume your snow looks like round things is not what happens in the sky."

The P-3, which was outfitted in November with the instruments it will carry during this campaign, will be based in Virginia. The high-flying ER-2 will be based in Georgia, outside the storm centers for easier takeoff and landing. The team hopes to observe storms around New York State including Long Island, where partners are collecting ground observations. The final flight routes will depend on the storm paths that nature delivers.

In the days leading up to a promising storm, the mission scientists will map out the flight paths. Depending on how far the storm is from Wallops Flight Facility, which determines the travel time to the storm, the aircraft can collect observations for four to six hours. The campaign also will use ground instruments and balloons to help complete the picture.

The observations will be used to study how snowstorms evolve and improve satellite observations of snowfall.

"I just love winter storms, they've always fascinated me. So it's very exciting to find out how they work, and how snow gets distributed the way it does," McMurdie said.

Barcelona, 10 December 2019. A team led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by "la Caixa", has carried out a study to identify lifestyle habits that influence the risk of overweight and obesity in children. Of the behaviours analysed in the study, television watching had the strongest association with overweight and obesity.

The study, published in the journal Pediatric Obesity, was based on data from 1,480 children from Sabadell, Gipuzkoa and Valencia enrolled in the birth cohort of the INMA Environment and Childhood Project, a Spanish research network that studies the role of pollutants during pregnancy and their effects on children. The researchers analysed five lifestyle habits: physical activity, sleep time, television time, plant-based food consumption and ultra-processed food consumption. Parents were asked to complete various questionnaires on the children's lifestyle habits at four years of age. To calculate the health impact of these habits, the researchers measured the children's body mass index (BMI), waist circumference and blood pressure at four and seven years of age.

"Most research to date has focused on the impact of individual lifestyle behaviours rather than cumulative effects," commented Martine Vrijheid, co-leader of the study and researcher in the ISGlobal Programme on Childhood & Environment. "However, it is well known that unhealthy behaviours tend to overlap and interrelate. Our aim in this study was to examine the whole set of lifestyle behaviours with a view to facilitating the development of interventions capable of targeting the determinants of obesity from a broader perspective."

Television Encourages Bad Habits

The study findings showed that children who were less active and spent more time in front of the television at four years of age were at greater risk of being affected by overweight, obesity and metabolic syndrome at seven years of age. The researchers also measured the time spent by the children on other sedentary activities, such as reading, drawing and doing puzzles. However, these activities did not appear to be associated with overweight or obesity.

"When children watch television, they see a huge number of advertisements for unhealthy food," commented ISGlobal's Dora Romaguera, co-leader of the study. "This may encourage them to consume these products." Ultra-processed foods, such as pastries, sweet beverages and refined-grain products, are high in sugar, salt and saturated fat and low in nutritional value. The study showed that high intake of these products at four years of age was associated with a higher BMI at seven years of age.

Moreover, television viewing "discourages physical activity and interrupts sleep time", explained Sílvia Fernández, a post-doctoral researcher at ISGlobal. As the researchers noted, adequate sleep time in early childhood is essential for weight control later in childhood. "Previous studies have shown that 45% of children are not sleeping the recommended number of hours per night," explained Fernández. "This is worrying because shorter sleep time tends to be associated with obesity."

"Identifying habits linked to overweight and obesity in the early stages of life can help us to define preventive strategies against other conditions, such as cardiovascular and metabolic diseases during adulthood," commented Rowaedh A. Bawaked, researcher at the Hospital del Mar Medical Research Institute and lead author of the study. The study concluded that adult health depends on the establishment of healthy lifestyle habits during childhood: limited television time, extracurricular physical activity, getting enough hours of sleep, eating lots of vegetables and avoiding ultra-processed foods.

The identification of natural carbon sinks and understanding how they work is critical if humans are to mitigate global climate change. Tropical coastal wetlands are considered important but, so far, there is little data to show the benefits. This study, led by the University of Göttingen with the Leibniz Centre for Tropical Marine Research in Bremen, and the University of Bremen showed that mangrove ecosystems need to be conserved and restored as part of the battle against rising carbon levels in the atmosphere. The research was published in Global Change Biology.

Researchers conducted the study in the mangrove-fringed Segara Anakan Lagoon in Java, Indonesia. This coastal lagoon is known to be one of the most effective carbon sinks amongst mangrove ecosystems around the world. The researchers analysed a five-meter-deep core of sediment for its age and biogeochemical composition, as well as elements, pollen and spores. They investigated four different time periods across 400 years and varying climates, integrating data from ecological and societal changes with land and coastal changes.

The results show that the environmental dynamics in the lagoon and carbon accumulation were controlled mainly by fluctuations in the climate and human activity. The researchers found that the interaction of these two factors affected the lagoon's sediment and saltiness, which then went on to alter the composition of the organic matter (which contains carbon), and how it was deposited in the lagoon thus adding to the "sink of carbon". They also found that the weather was the chief driver in washing carbon compounds, in the form of organic matter, to the lagoon from remote areas far from the coast. In earlier times, these remote areas consisted of natural mixed forest but more often now they are agricultural land.

Coastal lagoons, such as Segara Anakan, are particularly threatened both by destruction of the mangroves by people and the effects of global environmental change, such as rising sea levels. The rising water in turn causes coastal erosion, extreme floods and habitat loss, which endangers society. "Our research shows that people need to prioritise mangrove ecosystems for conservation and restoration because mangroves absorb carbon efficiently," says first author Dr Kartika Anggi Hapsari from the Department of Palynology and Climate Dynamics at Göttingen University. "It is not enough just to focus on cutting carbon emissions. Society needs to also identify efficient and natural ecosystems, like those dominated by mangrove vegetation, to remove carbon."

"This research also really emphasises the importance of interdisciplinary working," Hapsari adds. "In this case, palaeoecological researchers, who look at organism and environmental interactions across geologic timescales, worked with researchers from biogeochemistry, who look at organic chemical compounds in sediment, historical cartography and socio-economy to relate the changes in landscape and socioeconomic condition over time. By combining different perspectives, we can be sure our results reach the right conclusion and are meaningful."

Magazine adverts continue to tell mothers to put caring for their families front and centre - and encourage them to devote all their knowledge to protecting and caring for them rather than for their own benefit or professional advancement.

A study of adverts in women's magazines since the 1950s found they present mothers with an idealised image of the 'knowing mother', where they are exhorted to put all their expertise to use in service to the family.

Researchers from the University of Sydney, Lancaster University, the University of Edinburgh, Monash University and St Gallen University studied advertisements in Australian Women's Weekly and Good Housekeeping, in the UK, for each decade between 1950 and 2010.

Their findings, published in the Journal of Consumer Culture, show that the visual representation of mothers as knowledgeable consumers for the whole family changed over the period, from being guided by experts to possessing expertise themselves.

However, assumptions about their responsibilities endured, as advertisers repeatedly positioned them in terms of their domestic responsibilities, such as cooking and cleaning, using their knowledge for family purposes and not necessarily for their own gain or professional pursuits.

"Knowing how to consume correctly for the family has become a major definer of female identity," said report lead author Professor Teresa Davis, of the University of Sydney Business School.

"The caring mother is one of the most recurring images of femininity in post-war advertising. Representations of the good mother are especially evident in relation to her consumption for the family through her knowledge of cooking, caring and cleaning 'correctly'.

"The advertisements we looked at place an emphasis on what mothers can, should and need to know, inviting readers to compare themselves with the ideal they are presented with.

"Despite shifts in attitudes that appear to share the role of caring within a family, there exists an enduring assumption that mothers should be responsible. Adverts increasingly position mothers as being required to acquire more expertise and skills to professionalise their mothering and to use this knowledge largely for maternal purposes."

The researchers found a shift in the representation of mothers in advertising over the 60-year period studied.

In the 1950s, adverts show mothers following the advice of (mainly male) experts such as doctors, celebrities and psychologists, on how to 'consume correctly' and care for their children. They would decide which particular brands of toothpaste, vitamins or clothing they should buy, with their choices legitimised by being 'doctor' approved. Images highlight the pressures of intensive mothering, with the knowledgeable mother one who happily sacrifices her time to make the right decisions for her family.

The theme continued into the 1960s and 1970s, with maternal knowledge drawing on scientific statements and experts in adverts, providing a grounding for decisions. While professional and domestic lives intertwine in the 1980s and 1990s, mothers use their professional skills and knowhow to consume efficiently for the family.

By 2000 and 2010, the mother becomes the expert herself, no longer passively following instructions, instead negotiating their way around complex scientific facts and sifting through claims about subjects such as genetically modified foods. She needs to know enough to be able to question experts; however, the adverts still represent mothers as possessing and striving for this knowledge primarily for the protection of their families and children.

""Through the decades we studied, we can trace the transformation of the depiction of mothers from someone informed by experts about how to consume for her family to someone who is an expert herself," said co-author, Professor Margaret K. Hogg, of Lancaster University Management School. "The mother who listens to the voice of the knowledgeable expert is present in advertisements in the early decades of our study, between 1950 and 1970.

"There is a major shift in recognising a woman's place as a holder of scientific knowledge. This is not just around the family, but also on issues such as the environment, sustainability, illness and well-being.

"In 2000 and 2010, the authoritative expert is replaced by the mother as the expert herself. It is no longer enough to follow implicitly an expert's instructions, the mother needs to know enough to be able to ask questions about climate change, cognitive development and GMO food, to know how to consume and protect her children. The adverts show them using their knowledge predominately to consume well on behalf of their children, thus fulfilling their primary maternal role."

This use of knowledge for the family is a common theme throughout the advertisements studied by the researchers in both Good Housekeeping and Australian Women's Weekly, be they for washing powder, vitamin supplements, tissues or disinfectants.

"In all instances, the representation of the knowing mother is presented as what mothers should aspire to, and this is an enduring vision across seven decades and two continents," said co-author Professor David Marshall, of the University of Edinburgh Business School.

"Although knowledge changes over the decades, it remains bent towards the pursuit of a selfless maternal ideal, strengthening gender stereotypes and the traditional hegemony.

"Women's knowledge is rarely used for personal gain - usually not in professional roles, such as a doctor or environmental scientist - but rather is harnessed to the highest purpose: that of carefully informed maternal consumption for the family."

A previously unknown mechanism that suppresses satiety signals from the small intestine is the main finding of a new study. This may explain, first, satiety disorders in obesity and diabetes and, second, the prompt health effects of gastric bypass, a form of bariatric surgery.

The study, published in the BMJ journal Gut, is based on investigations of the small intestinal mucous membrane in postoperative gastric bypass patients, as well as in mice and cell cultures. The finding concerns a research field in which many scientists have long sought associations and mechanisms of the kind now presented.

The focus of the study is on the intestinal hormone glucagon-like peptide (GLP)-1, which belongs to a group of satiety hormones that are released from food sensitive hormone producing cells in the gastrointestinal mucous membrane when we eat. These hormones regulate appetite by signaling satiety to the brain in order to end meals and they increase secretion of insulin from the pancreas.

For reasons that are unclear, release of GLP-1 and other similar acting satiety-signaling hormones is inhibited in patients with obesity and type-2 diabetes, and this is considered to be a key causal mechanism underlying these disorders. Therefore, several modern medicines against diabetes and overweight copy, or mimic, GLP-1 in order to try to imitate the normal secretion of this substance.

What the researchers have found is a mechanism in the small intestine that can explain how the satiety signaling is inhibited. The culprit is mHMGCS (mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase), an enzyme that triggers the formation of ketone bodies in the intestinal mucous membrane that, in turn, dampen the GLP-1 release from the hormone-producing cells in response to meals.

Mouse experimentation showed that the process was diet-dependent. In mice that, over a long period, were given a high-fat diet, a massive rise in enzyme production took place. This was accompanied by increasing production of ketone bodies, which proved to suppress release of GLP-1 from the hormone-producing cells.

The study was conducted by a research group at Sahlgrenska Academy, University of Gothenburg, and Sahlgrenska University Hospital. The scientists were seeking to answer the question of why, in patients who undergo gastric bypass surgery, there is a very rapid reversion from extremely low to normal levels of GLP-1 within days. The group's previous research shows that this change takes place within two days after the operation, long before the patients start losing weight.

"We now have a conceivable explanation for this: That a gastric bypass quite simply disconnects the part of the digestive system in which the problem, the ketone-body production, arises," says Ville Wallenius, associate professor and senior consultant in bariatric surgery and the principal author of the study.

"After the operation, food enters directly from the esophagus into the jejunum (the middle section of the small intestine) without passing the stomach and the duodenum. Then, when the food is no longer being mixed with bile and pancreatic enzymes that break down dietary fat into free fatty acids, that act as precursors for the ketone formation, the preconditions for the enzyme that triggers the ketone production simply disappear."

Lars Fändriks, a professor of bariatric surgery, describes the findings on ketone body formation in the small intestine in response to food intake as controversial and puzzling.
"Ketone bodies are usually produced in the liver during starvation and are essential to our survival. For example, during starvation, the brain is dependent on ketones as its primary energy source when it can't be met with glucose. Ketogenesis, the ketone production of the small intestine, seems to fulfill a completely different function," Fändriks says.

The scientists believe that these findings will open up for a new type of drugs. Instead of injecting copies of GLP-1, it might be possible to pharmacologically block the enzyme mHMGCS in the intestine. This would stop the suppression of the hormone-producing cells, which could thereby increase their release of both GLP-1 and other satiety hormones.

"That kind of drug could imitate the effect of the gastric bypass operation," Ville Wallenius concludes.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties - for example, they may ex-hibit conducting, semiconducting or insulating behavior. However, one property has so far been elusive: magnetism. Together with colleagues from the Technical University in Dresden, Aalto University in Finland, Max Planck Institute for Polymer Research in Mainz and University of Bern, Empa researchers have now succeeded in building a nanogra-phene with magnetic properties that could be a decisive component for spin-based elec-tronics functioning at room temperature.

Graphene consists only of carbon atoms, but magnetism is a property hardly associated with carbon. So how is it possible for carbon nanomaterials to exhibit magnetism? To un-derstand this, we need to take a trip into the world of chemistry and atomic physics.

The carbon atoms in graphene are arranged in a honeycomb structure. Each carbon atom has three neighbors, with which it forms alternating single or double bonds. In a single bond, one electron from each atom - a so-called valence electron - binds with its neigh-bor; while in a double bond, two electrons from each atom participate. This alternating single and double bond representation of organic compounds is known as the Kekulé structure, named after the German chemist August Kekulé who first proposed this repre-sentation for one of the simplest organic compound, benzene (Figure 1). The rule here is that electron pairs inhabiting the same orbital must differ in their direction of rotation - the so-called spin - a consequence of the quantum mechanical Pauli's exclusion princi-ple.

"However, in certain structures made of hexagons, one can never draw alternating single and double bond patterns that satisfy the bonding requirements of every carbon atom. As a consequence, in such structures, one or more electrons are forced to remain unpaired and cannot form a bond," explains Shantanu Mishra, who is researching novel nanogra-phenes in the Empa nanotech@surfaces laboratory headed by Roman Fasel. This phe-nomenon of involuntary unpairing of electrons is called "topological frustration".

But what does this have to do with magnetism? The answer lies in the "spins" of the elec-trons. The rotation of an electron around its own axis causes a tiny magnetic field, a mag-netic moment. If, as usual, there are two electrons with opposite spins in an orbital of an atom, these magnetic fields cancel each other. If, however, an electron is alone in its or-bital, the magnetic moment remains - and a measurable magnetic field results.

This alone is fascinating. But in order to be able to use the spin of the electrons as circuit elements, one more step is needed. One answer could be a structure that looks like a bow tie under a scanning tunneling microscope.

Two frustrated electrons in one molecule

Back in the 1970s, the Czech chemist Erich Clar, a distinguished expert in the field of nanographene chemistry, predicted a bow tie-like structure known as "Clar's goblet" (Fig-ure 1). It consists of two symmetrical halves and is constructed in such a way that one electron in each of the halves must remain topologically frustrated. However, since the two electrons are connected via the structure, they are antiferromagnetically coupled - that is, their spins necessarily orient in opposite directions.

In its antiferromagnetic state, Clar's goblet could act as a "NOT" logic gate: if the direction of the spin at the input is reversed, the output spin must also be forced to rotate.

However, it is also possible to bring the structure into a ferromagnetic state, where both spins orient along the same direction. To do this, the structure must be excited with a cer-tain energy, the so-called exchange coupling energy, so that one of the electrons reverses its spin.

In order for the gate to remain stable in its antiferromagnetic state, however, it must not spontaneously switch to the ferromagnetic state. For this to be possible, the exchange coupling energy must be higher than the energy dissipation when the gate is operated at room temperature. This is a central prerequisite for ensuring that a future spintronic cir-cuit based on nanographenes can function faultlessly at room temperature.

From theory to reality

So far, however, room-temperature stable magnetic carbon nanostructures have only been theoretical constructs. For the first time, the researchers have now succeeded in pro-ducing such a structure in practice, and showed that the theory does correspond to reali-ty. "Realizing the structure is demanding, since Clar's goblet is highly reactive, and the synthesis is complex," explains Mishra. Starting from a precursor molecule, the researchers were able to realize Clar's goblet in ultrahigh vacuum on a gold surface, and experimen-tally demonstrate that the molecule has exactly the predicted properties.

Importantly, they were able to show that the exchange coupling energy in Clar's goblet is relatively high at 23 meV, implying that spin-based logic operations could therefore be stable at room temperature. "This is a small but important step toward spintronics," says Roman Fasel.

Physicists at the Weizmann Institute of Science in Israel have imaged electrons flowing viscously through a nanodevice, just like water flowing through a pipe. Long predicted but only now visualized for the first time, this curious new behavior for electrons has important implications for future electronic devices.

From roaring waves to swirling whirlpools, the flow of a liquid can be extremely rich. Such varied phenomena are the result of the many collisions that occur between the particles that make up a liquid, and is described by the physics of hydrodynamics. However, despite being negatively charged, electrons usually flow through a conductor like a gas in a randomized fashion essentially without repelling each other. This is because most conductors are made from materials that are highly disordered, and the electrons flowing inside collide more frequently with the many impurities and imperfections. To make electrons flow like a liquid, one needs a more advanced conductor, for example, graphene -- a one atom-thick sheet of carbon, which can be made exceptionally clean. "Theories suggest that liquid electrons can perform cool feats that their ballistic or diffusive counterparts cannot. But to get a clear-cut proof that electrons can indeed form a liquid state, we wanted to directly visualize their flow," said Prof. Shahal Ilani, head of the Weizmann team in the Department of Condensed Matter Physics.

Visualizing hydrodynamic electron flow in a material like graphene isn't straightforward, though, as it requires a special technique that is simultaneously powerful enough to peer inside a material, yet gentle enough to avoid disrupting the electron flow. The Weizmann team created such a technique, which they published recently in Nature Nanotechnology [1]. They produced a nanoscale detector built from a carbon nanotube transistor that can image the properties of flowing electrons with unprecedented sensitivity. "Our technique is at least 1000 times more sensitive than alternative methods, which enables us to image phenomena that previously could only be studied indirectly," said Dr. Joseph Sulpizio, from Weizmann.

In their new paper, now published in Nature [2], the Weizmann researchers applied their novel imaging technique to state-of-the-art graphene devices produced by the group of Prof. Andre Geim at the University of Manchester. These devices are shaped into channels that guide the flowing electrons, similar to the way a pipe guides the flow of water. And just as water flows through a pipe, the electrons in the graphene were observed flowing faster in the center of the channels and slower at the walls, which is the hallmark of hydrodynamic flow.

This work demonstrates that the patterns of a conventional fluid can be mimicked by electrons. This may prove beneficial for creating new types of electronic devices, including low-power devices in which the hydrodynamic flow lowers the electrical resistance. "Computing centers and consumer electronics are devouring an ever-increasing amount of energy, and in light of climate change, it's imperative to find ways to make electrons flow with less resistance," said Dr. Lior Ella from Weizmann.

A new study led by the Sainte-Justine University Hospital Centre and the University of Montreal, along with the Washington University School of Medicine in St. Louis, has found that transfusions using fresh red blood cells--cells that have spent seven days or less in storage--are no more beneficial than older red blood cells in reducing the risk of organ failure or death in critically ill children. The results are published online today in the Journal of the American Medical Association.

Anemia is highly prevalent among children hospitalized in pediatric intensive care units. Transfusion with red blood cells is the only way to rapidly treat severe anemia that could be life-threatening. Red blood cells are stored in blood banks as red-cell units for up to 42 days. Some studies published over the past few decades have suggested that transfusion with red blood-cell units stored for longer periods might be less beneficial than transfusion with fresher red-cell units. The new findings should reassure patients, families and doctors: the current standard blood-bank practice of dispensing older red cells is just as safe and effective for children in intensive-care, among the sickest and most fragile of patients.

The study, one of the largest clinical trials to investigate red blood-cell storage for critically ill children, sheds light on a controversial and neglected aspect of transfusion medicine. The study was funded by the Canadian Institutes of Health Research (CIHR) in Canada, by the National Heart, Lung, and Blood Institute (NHLBI) in the U.S., by the Programme Hospitalier de Recherche Clinique (PHRC) in France and by the Quebec Ministry of Health.

The study was led by two principal investigators: Dr. Marisa Tucci of Sainte-Justine and Dr. Philip Spinella of Washington University; both are pediatric intensivists and researchers. According to the investigators, the findings indicate that doctors who care for children in pediatric critical-care units should not be afraid to use older red cells in their patients. The results from this study suggest that those who systematically request fresh red cells should consider discontinuing this practice unless there are extenuating circumstances. The findings also provide good news for blood banks, who will likely feel less pressure to respond to requests for fresh red cells.

Red blood-cell transfusions are commonly administered in critically ill children who have illnesses that increase the need for transfusion, such as trauma, cancer chemotherapy, major surgery with significant intraoperative bleeding, and conditions such as sickle cell disease and thalassemia. Transfusing the oldest red cells in the stored inventory first is standard practice among many hospitals to avoid wastage. However, some hospitals preferentially give fresh red blood cells to critically ill children, even though clinical studies supporting the benefits of this practice have been lacking.

To help fill the research gap, the investigators of the 'Age of Blood in Children in Pediatric Intensive Care Units' (ABC-PICU) study undertook a randomized trial that recruited patients admitted to pediatric intensive care units in 50 medical centres. The study began in February 2014 and ended in November 2018; 1,461 children ranging in age from 3 days to 16 years who were admitted to pediatric intensive care units were recruited in the United States (29 sites), Canada (10 sites), France (8 sites), Italy (2 sites), and Israel (1 site); Sainte-Justine University Hospital was the coordinating centre in Canada and recruited the greatest number of patients (over 160). Data management and analysis was done by Dr. Dean Fergusson of the Centre for Practice-Changing Research at the University of Ottawa, in coordination with Drs. Tucci and Spinella.

During the course of the study, half of the patients received transfusions with fresh red blood cells stored for seven days or less and half received transfusions with older red cells. The primary outcome measured was the development of new or progressive multiple-organ dysfunction (impairment of one or more organs). The researchers found that fresh red cells did not reduce the incidence of new or progressive multiple-organ dysfunction or death compared to older red cells and that the outcomes were not significantly different between the two groups. About 20.2 per cent of those who received fresh red cells experienced new or progressive organ dysfunction while 18.2 per cent of those who received older red cells experienced similar dysfunction.

The relatively large number of patients recruited and their geographic diversity, as well as the inclusion of a wide variety of patients, were among the study's strengths, making it reasonable for researchers to generalize the findings to a larger pediatric population. The researchers did note some caveats, however. The study did not examine whether the use of the oldest red cells allowable (more than 35 days) affects outcomes, or whether fresh red cells affect outcomes for children requiring large-volume red cell transfusions. The children in this study received low-volume red cell transfusions.

The results of this study are applicable to the vast majority of children in pediatric intensive care units and show that current red blood-cell transfusion practices are safe.

Over $650 million annually is raised for medical needs on the crowdfunding platform GoFundMe, with 1,059 campaigns for unproven and potentially dangerous interventions identified in one search. Crowdfunding campaigns can "mislead donors, spread misinformation and may even harm those receiving the money," write authors Jeremy Snyder and I. Glenn Cohen in "Medical Crowdfunding for Unproven Medical Treatments: Should GoFundMe Become a Gatekeeper?" "We urge GoFundMe and other crowdfunding platforms to move forward with restricting campaigns for unproven medical treatments more widely and as soon as possible given the ongoing and growing harms of inaction," they write. GoFundMe and similar platforms are aware they are being used in potentially unethical campaigns, yet they have done little to stop them, the authors maintain.

In "Physician Burnout Calls for Legal Intervention," Sharon Hoffman writes that hospitals with a high burnout rate among doctors should receive lower payments from Medicare, among other measures. Hoffman argues that the law routinely safeguards the health of workers such as pilots and air traffic controllers in safety-critical professions - and, as physician's jobs are also safety-critical, they also deserve focused legal intervention.

"Sugar, Taxes, & Choice" addresses objections to taxing sugar-sweetened beverages, noting that they have been prominent in the public debate on the grounds that they interfere with individuals' freedom and autonomy. The authors make the case that these arguments are often compromised by confusion over the concepts of freedom and autonomy. They explain why less freedom does not necessarily entail less autonomy.

Also in the issue: Emergency room doctor Jay Baruch writes about an embarrassing encounter with a patient in "Why Won't My Patient Act Like a Jerk?" A set of essays (by Tod S. Chambers, Arthur W. Frank, and Philip M. Rosoff) explores the ethics of writing stories of patient care. Rebecca Dresser analyzes the legal issues in executing a prisoner with dementia, and Hilde Lindemann warns that gender is bad for your health.

The table of contents and abstracts are available at https://onlinelibrary.wiley.com/toc/1552146x/2019/49/6

Most synthetic materials, including those in battery electrodes, polymer membranes, and catalysts, degrade over time because they don't have internal repair mechanisms. If you could distribute autonomous microrobots within these materials, then you could use the microrobots to continuously make repairs from the inside. A new study from the lab of Kyle Bishop, associate professor of chemical engineering, proposes a strategy for microscale robots that can sense symptoms of a material defect and navigate autonomously to the defect site, where corrective actions could be performed. The study was published in Physical Review Research December 2, 2019.

Swimming bacteria look for regions of high nutrient concentration by integrating chemical sensors and molecular motors, much like a self-driving car that uses information from cameras and other sensors to select an appropriate action to reach its destination. Researchers have tried to mimic these behaviors by using small particles propelled by chemical fuels or other energy inputs. While spatial variations in the environment (e.g., in the fuel concentration) can act to physically orient the particle and thereby direct its motion, this type of navigation has limitations.

"Existing self-propelled particles are more like a runaway train that's mechanically steered by the winding rails than a self-driving car that's autonomously guided by sensory information," says Bishop. "We wondered if we could design microscale robots with material sensors and actuators that navigate more like bacteria."

Bishop's team is developing a new approach to encode the autonomous navigation of microrobots that is based on shape-shifting materials. Local features of the environment, such as temperature or pH, determine the three-dimensional shape of the particle, which in turn influences its self-propelled motion. By controlling the particle's shape and its response to environmental changes, the researchers model how microrobots can be engineered to swim up or down stimulus gradients, even those too weak to be directly felt by the particle.

"For the first time, we show how responsive materials could be used as on-board computers for microscale robots, smaller than the thickness of a human hair, that are programmed to navigate autonomously," says Yong Dou, a co-author of the study and a PhD student in Bishop's lab. "Such microrobots could perform more complex tasks such as distributed sensing of material defects, autonomous delivery of therapeutic cargo, and on-demand repairs of materials, cells, or tissues."

Bishop's team is now setting up experiments to demonstrate in practice their theoretical navigation strategy for microrobots, using shape-shifting materials such as liquid crystal elastomers and shape memory alloys. They expect to show the experiments will prove that
stimuli-responsive, shape-shifting microparticles can use engineered feedback between sensing and motion to navigate autonomously.