Earth

FOOD HABITS The assumption that an elderly widower can hardly boil an egg simply doesn't stand according to a recent University of Copenhagen study. The study reports that male seniors do cook and only blossom in the kitchen once alone. Widows appear to be less interested in cooking. The new findings can be useful for municipal elder care and suggest that changing gender roles don't just apply to younger generations.
Elderly man
Photo: Getty

When older men lose a partner, there is an assumption that, due to traditional gender roles, they are helpless in the kitchen, fall by the wayside and end up living off of ready-to-eat meals and municipal food services because they've never learned to cook.

However, results from a new study at the University of Copenhagen's Department of Food and Resource Economics suggest that that this assumption may no longer hold water. In-depth interviews with 31 widowed men and women ages 67 to 86 paint a more nuanced picture.

"There's been a long-held assumption that older men are challenged in the kitchen, practically speaking, when living on their own. But, that's not what I see. While there are single men from older generations who are challenged, there are also those who are adept in the kitchen and who have taken up the challenge of cooking once alone. And perhaps, even after a wife has fallen ill or upon their own retirement," says researcher and assistant professor Sidse Schoubye Andersen, the study's author.

The researcher asserts that this behaviour surrounding cooking accords with the times, as men increasingly take part in household chores, but which also contradicts the well-known and somewhat gloomy narrative of the single man.

Men make pâtés and sausages from scratch, women eat cheese sandwiches

Many of the widowers in the study experience cooking as a new hobby, one in which they most notably flourish in relation to meat dishes, when asked, for example, what they ate the day prior to the interview. Sidse Schoubye Andersen explains:

"The men recounted in detail how they had prepared a pork roast or made sausage and liver pâté from scratch. While the dishes they prepared were often quite elaborate, they reported making them because they thought it was fun to do so and because it was important for them to have a hot meal." She adds:

"The men were worried about being considered helpless or dependent upon others when it came to cooking. It was important for them to demonstrate that they could take care of themselves and be distanced from the man who 'goes to the dogs' upon the passing of his spouse."

A different picture emerged among widowed women. Here, according to the researcher, the trend was that cooking ought not take longer than the time required to eat, and that cooking was considered more of a chore.

"The women told me that they weren't interested in spending too much time on cooking for themselves, and could often settle for some bread and cheese. One of them said that despite being terribly sorry to have lost her husband, the fact that she no longer had to cook was perfectly okay and somewhat of a relief," explains Schoubye Andersen.

Old age precipitates new gender roles

According to the researcher, the results are in part an indication that men and women perceive cooking differently, probably due to differing divisions of labour throughout life; men consider cooking a hobby, women see it as daily work. But these divergent narratives also express the gendered expectations of older men, women and their food habits.

"When an older woman describes skipping meals or eating bread and cheese, we interpret it as an expression of a priority. She needn't defend or explain it. Conversely, when older men make a big deal about not skipping a meal and detail their elaborate concoctions, it is partly because they seek to distance themselves from the image of a helpless widower," explains Sidse Schoubye Andersen.

The study is one of very few conducted in this area, which, according to the researcher, is partly due to the fact that as a society, we often forget to include older generations when appreciating changed gender roles. For example, we assume that seniors live according to traditional patterns and, as such, don't reflect modern trends.

"The results of this study reflect that some of the changes apparent in the gender roles of modern families are also at play among seniors. But we often forget to carry out research into changes in old age - because we assume that change and development are primarily a matter of youth," says Schoubye Andersen.

She hopes that the study can contribute new knowledge and add nuance to the picture of the seniors who live alone, e.g. in connection with preventive home visits by municipalities, which falls under the Danish Social Service Law.

Photo-induced electron transfer is central to numerous physical processes, for instance in the magnetization of materials. The quest to understand and control this ultrafast process has long been pursued in vain, with no answer to the question of whether electrons induce atomic motion, or vice versa. To answer this question, the atomic equivalent of the paradox of the chicken and the egg, a consortium of scientists led by the Institute of Physics in Rennes (CNRS/Université de Rennes 1)[1] used an X-ray laser (X-FEL) located in Stanford.[2] This latest-generation instrument can observe, in real time, the electrons and atoms that make up matter. In the system studied, experiments showed that light triggers the ultrafast distortion of the molecular structure of cobalt atoms. This leads to the transfer of iron atoms toward cobalt atoms, thereby making the system magnetic. This research, published in Nature Chemistry on December 7, 2020, shows that it is possible to distinguish between the electronic dynamics of atomic motion on the scale of one tenth of one millionth millionth of a second (or 100 femtoseconds). This opens the way for the development of a science that can control materials through light.

Climate change has and will continue to induce severe increases in summer temperatures throughout Europe, especially in the Mediterranean region, where Italy stands out in terms of heat-related effects on daily mortality. In particular, the "urban heat island" effect makes it essential to understand context specific heat-health risks in cities in order to manage them with appropriate policy measures.

The association between heat and mortality depends on social vulnerability, which is in turn influenced by demographic, social and economic factors. Some sub-groups of the population are therefore more at risk as temperatures rise. Which are these groups?

A recent study coordinated by the Instituto de Salud Global de Barcelona (ISGlobal) and the CMCC Foundation investigates how social inequalities can affect heat stress in South European urban contexts through the case study of the city of Turin, Italy. The outcomes of the study are presented in the paper "Social inequalities in heat-attributable mortality in the city of Turin, northwest of Italy: a time series analysis from 1982 to 2018", published in the scientific journal Environmental Health. Using an innovative methodology, the research associates daily temperatures and daily mortality in summer in the city of Turin for the period 1982-2018. Results show how the effect of heat on mortality varies widely between different population groups, divided by socio-demographic characteristics.

The mortality risk is higher for women than for men, and increases with age in both sexes. This study, however, considers not only the demographic aspects (age and gender) already explored in the literature, but also the level of education, the marital status and the number of household occupants: such socioeconomic variables are considered important for identifying the most vulnerable targets to heat stress. The women most at risk are those with the lowest educational levels, whereas the strongest effects on men are observed at the extremes (highest and lowest levels of education). Individuals living alone (such as the unmarried, separated, divorced and widowed), regardless of gender, were found to be at greater risk than married people. Finally, the association between heat and mortality was higher for men who live alone than for those who share a home with other people. For women, this difference is almost nil.

There are many studies on the link between heat and health, but few of them analyse the Italian context, especially using specific case studies. "We have chosen to focus on the city of Turin due to the availability of a very long historical series of daily data on mortality and hospitalization records crossed with the socio-economic components of the population. Talking about climate change it is necessary to consider sufficiently long periods of time. This data, made available by the Regional Public Health Observatory (SEPI) of the Local Health Board TO3, covers a 37 year period: there are few datasets available in Europe so long and rich in variables," says Marta Ellena, CMCC researcher and lead author of the study.

This study paves the way for a series of further investigations that will support urban decision making to improve heat-health risk management. The next step will be to determine how this risk varies over time and how it is diversified on a sub-urban scale. "The need to determine the distribution of heat risk at a sub-urban level is increasingly clear: this comprehension can help to mitigate such risk by designing cities in the best possible way through all the strategies available, from the use of green areas to the choice of the building materials" explains Paola Mercogliano, director of the Regional Models and geo-Hydrological Impacts division at the CMCC Foundation. "Furthermore, the usefulness of this research extends to other contexts. Each sub-urban area refers to hospital centers: if heat waves are combined with ongoing epidemics, the number of people that need access to these centers could increase. As the current pandemic is showing us, it is good to be prepared".

The REMHI division of the CMCC Foundation is developing climate models at very high resolution (2 km). In the future, thanks to these models, it will also be possible to evaluate the evolution of heat stress on the urban population for different cities, thus identifying priority actions in terms of adaptation in order to prevent health risks.

Over the past several decades, marine protected areas (MPAs) have emerged as a favored conservation tool. By protecting marine species and safeguarding habitat, these reserves help buffer ecosystems against natural and human-made shocks alike.

Researchers at UC Santa Barbara and the National Oceanic and Atmospheric Administration (NOAA) sought to determine how well MPAs protect fish from changes caused by marine heatwaves. These stressful events can drastically alter an ecosystem, and scientists predict they will increase in frequency and intensity as the climate warms.

To answer these questions, the team took advantage of a marine heatwave that affected the entire West Coast between 2014 and 2016, using 16 years of data from the Channel Islands. The archipelago lies at the transition between subtropical ecosystems in the south and temperate ecosystems north of Point Conception, and is dotted with a network of a dozen or so no-take reserves.

According to the researchers' findings, published in the journal Scientific Reports, MPAs do little to mediate some effects of marine heatwaves, including, in this case, changes to fish community structure. Resource managers will have to employ other strategies if they want to mitigate this challenge, the research shows.

No-take marine protected areas are extremely useful strategies for marine conservation. Because they are a whole-ecosystem management tool, many scientists believe they can help mitigate climate shifts. Prior research has shown that MPAs can increase species' numbers, stabilize ecosystems and even increase fishery catches - all effects that should, in theory, offer protection against climate change.

"There have been many studies showing that MPAs are effective at preserving biodiversity and facilitating recovery of single species during and after extreme temperature events," said lead author Ryan Freedman, a former doctoral student in the lab of Jennifer Caselle, a researcher at UCSB's Marine Science Institute. "Given these aspects, and the body of work on MPA benefits, a lot of resource managers point to MPAs as a way to mitigate climate effects even though there have been just a few studies on the topic."

Fortunately, Freedman and his team had a wealth of data from around the Channel Islands thanks to PISCO, the Partnership for Interdisciplinary Studies of Coastal Oceans. The academic consortium conducts research on California's coastal ocean to inform management and policy. PISCO has datasets stretching back to 1999, as well as monitoring sites inside and outside the islands' MPAs.

Freedman made use of a marine heatwave that affected the region in 2014 as a sort of natural experiment. He compared fish density, biomass, biodiversity and the recruitment of juveniles between warm-water and cold-water species to investigate how the marine protected areas mediated the impact of the heatwave.

"We found that the heatwave had an outsized effect on density, recruitment and biodiversity compared to typical oceanographic events like El Niño," Freedman said. "Once we saw that, we focused on data just during the heatwave years to look closely at the trends inside and outside MPAs."

The team asked if fish communities inside the reserves remained similar before, during and after the heatwave in comparison to unprotected locations. Instead, they found little difference in the way that fish communities shifted inside and outside the MPAs.

The researchers were surprised by the results, but have formulated a possible explanation. They suspect that trends were similar within and without the MPAs because the heatwave tended to affect non-fished species -- like rock wrasses and Garibaldi -- more than those targeted by fisheries. For non-targeted species, the additional protection of a no-take marine reserve is a moot distinction when it comes to marine heatwaves.

"We suspect [non-]targeted species are more responsive because they are usually smaller and have shorter life histories than targeted species," Freedman explained. As a result, non-fished species likely feel a stronger impact from acute events like marine heatwaves. Additionally, non-targeted species are generally more abundant, which means there are more individuals for a heatwave to effect.

The implications of these findings seem pretty clear to Freedman. "Because MPAs alone can't mitigate acute ecosystem change during heatwaves, resource managers will need to use a suite of conservation options to maintain important ecosystem services in the Santa Barbara Channel and beyond as heatwaves become more common," he said.

This study also highlights the close partnership between UC Santa Barbara and the NOAA Channel Islands National Marine Sanctuary, where Freedman was employed during his Ph.D. and where he is now a research ecologist.

"Strong partnerships between academic researchers and resource managers are critical to solving some of the most difficult environmental challenges," said Caselle. "Having the office of the Channel Islands National Marine Sanctuary physically located on our campus is a huge benefit to researchers working on applied problems and managers looking for scientific solutions."

This is the first in a series of papers that aims to identify some of the ways an altered climate will impact the future of kelp forests in Southern and Central California. The team recently submitted another manuscript outlining how they classified warm-water and cold-water species in the hopes that other conservation groups can use their methodology to improve the accuracy their own work. The final paper in the series forecasts future changes in fish species under different climate scenarios for the Santa Barbara Channel, with a goal of allowing for proactive management in the face of climate change.

Increased funding for Head Start -- the largest federally funded, early childhood development program in the United States -- is needed to support families during the COVID-19 recession and to ensure a more stable economic recovery.

After studying a decade's worth of U.S. data around the 2007-09 Great Recession, researchers from Washington University in St. Louis, University of North Texas, University of Melbourne and the Maryland Population Research Center made the recommendation in a study published Dec. 5 in the journal Family Relations.

"History has shown that families who are already economically vulnerable are often the most harmed by a crisis and face the toughest recovery. COVID-19 has been no exception," said Caitlyn Collins, study co-author and assistant professor of sociology at Washington University in St. Louis. "Not only are many families facing extreme economic precarity, but school and childcare closings during the pandemic have removed major sources of support on which families rely.

"Head Start funding should be a national priority to support the nation's most vulnerable children and families."

Their study comes at a time of crisis for remote education and childcare due to the pandemic.

"In times of economic recession, programs like Head Start provide a vital resource for families who lack childcare support as they seek employment or return to work," the authors write.

"Yet, the availability of Head Start varies widely depending on a family's state of residence. Community agencies have discretion in allocating federal funds and state governments may supplement funding to expand Head Start availability and services."

William Scarborough (North Texas), Caitlyn Collins (WashU), Leah Ruppanner (Melbourne) and Liana Christin Landivar (Population Research Center) examined this state-by-state variation to study whether the availability of Head Start during the 2007-09 recession mitigated the impact of that crisis on poverty rates among families with young children.

Using data from the American Community Survey from 2006-16 and state-level data from program information reports, they found that states with higher levels of Head Start enrollment experienced less poverty growth among families with young children during the Great Recession. They also experienced a faster and more stable economic recovery than states with lower Head Start enrollment.

"The more children enrolled, the less poverty growth"

Predicted rates of family poverty from 2006 through 2016 for states where 20%, 60% and 100% of eligible children were enrolled in Head Start. These percentages capture approximate data points in the sample. For instance, Nevada has 22%, Illinois 60% and North Dakota 100% of all eligible children enrolled in their Head Start programs.

Despite starting out with higher rates of poverty among families with young children in 2006, states with higher Head Start enrollment did not experience as rapid an increase in family poverty up to 2012. In fact, by 2009, there was practically no difference in family poverty rates between high-, medium- and low-Head Start enrollment states. By 2012, low-enrollment states had poverty rates 1 percentage point higher than medium-enrollment states and nearly 2 percentage points higher than high-enrollment states.

Take Mississippi and Alabama, for example. Prior to the recession, the poverty rate in Mississippi -- where 90% of eligible children are enrolled in Head Start -- was about 6 percentage points higher than neighboring Alabama, where only 47% of eligible children attend these programs. When the recession started, family poverty rates increased faster in Alabama. As a result, the gap had fallen to 3.5 percentage points by the end of the recession in 2009. Mississippi also recovered faster with poverty rates beginning to decline in 2011, while Alabama did not peak until 2013. By 2016, the two states had nearly the same poverty rate.

"The findings suggest that greater access to Head Start programs prevented many families from falling into poverty and helped others exit poverty during the Great Recession," Scarborough said.

"As we face new challenges stemming from the COVID-19 pandemic, we urge policymakers to heed this evidence and designate funding to expand Head Start."

"Current funding can't keep up with growing demand"

Head Start is a school readiness program that offers free childcare for children 5 and under and provides comprehensive support services for eligible families. To be eligible, children must live in a family with income below the poverty line, receive other type of income-based public assistance and either be homeless or in foster care. Head Start operates in all 50 states and the District of Columbia.

Current federal funding for Head Start remains well below the established demand. At minimum, the research team recommends all states enroll 100% of eligible children without further restricting eligibility standards. Previous studies have estimated doing so would cost an additional $14.4 billion.

While this would more than double the current Head Start expenditures, the authors said this amount is "minuscule" when compared with other types of coronavirus relief spending.

Ideally, they recommend a more proactive approach: broaden eligibility guidelines and funding to help keep vulnerable families out of poverty.

Even with substantial increases to Head Start funding, the U.S. would likely lag behind many other developed countries in terms of early childhood education and care funding.

Currently, the U.S. devotes around 0.4% of GDP to early-childhood programs, coming in a lowly third-to-last among 17 Organisation for Economic Co-operation and Development (OECD) nations. By contrast, Sweden spends 1.8% of GDP on early childhood education, while France spending exceeds 1.3% and the United Kingdom spends 0.6% on these programs.

Beyond the economic benefits for families and communities, increased access to Head Start will help level the playing field for at-risk children.

"Early childhood education is vital to support children at a critical developmental stage that's fundamentally different than K-12 education," Collins said. "Wealthier families have more resources to ensure that their children receive high quality care at this important stage, but low-income families do not. Their children need high-quality care, too.

"This is a matter of funding priorities."

HERSHEY, Pa. -- White blood cells are part of many immune system responses in the human body. New research shows that a specific type of those cells may cause brain cancer tissues to die -- but that's not good news, according to researchers at Penn State College of Medicine. They said that higher amounts of this tissue death have been associated with poor survival in patients with aggressive glioblastomas, a deadly type of brain cancer that is common in adults.

Wei Li, assistant professor of pediatrics and biochemistry and molecular biology, studied the causes of this tissue death, called necrosis. Scientists have suggested that a lack of oxygen due to poor blood supply from rapid tumor growth may cause necrosis, but Li and a team of researchers investigated the molecular processes that cause this tissue death to occur. Their findings were published in Nature Communications.

"Glioblastoma patients with higher degrees of necrosis have a poor chance of survival," Li said. "We hope insight into the processes that drive this tissue death can help us develop new therapeutics to improve outcomes for these patients."

Li and the research team, including medical scientist training program student Patricia Yee, found that ferroptosis, a specific type of regulated cell death, caused tissue death. They examined tumor tissue samples from animal models of glioblastoma under a microscope and found that neutrophils, a type of white blood cell, were present in the same areas as dead tumor cells.

To establish whether these cells were part of the tissue death process, they decreased the amount of neutrophils in animal models, which then decreased the amount of necrosis in those cancer models. They also isolated these white blood cells and tested them against cancer cells in a lab and found that the presence of neutrophils prevented the cancer cells from thriving.

"We confirmed our theory on the role of neutrophils in necrosis by evaluating glioblastoma patient data," Li said. "A high number of neutrophils and the presence of genetic signals of ferroptosis were associated with pathological evidence of necrosis and predicted poor survival in patients."

Although they had a better idea of the key factor driving the tissue death, Li and colleagues were unsure why the tissue death was beneficial to tumor progression. They studied glioblastoma patient data sets and found that the dead cells secrete molecular signals that may help tumor cells grow.

Li, a Penn State Cancer Institute researcher, said future studies will investigate how the white blood cells that spur on the tissue death arrive at the tumor to begin with. He suspects that tissue damage from the tumor growth may be causing the neutrophils to arrive, but that further studies are needed. He also said more research is needed to better understand how necrosis promotes cancer growth.

"If we can develop therapeutic approaches for preventing necrosis, there's a chance those tumors might be less aggressive, which could be beneficial to glioblastoma patients," Li said.

Chronic sleep disruption during adolescence can lead to depression in both males and females and alters stress reactivity in females, according to a new study led by University of Ottawa researchers. Their findings, published in the journal Behavioral Brain Research, are particularly relevant in the context of a pandemic, when adolescents' mental health is already under strain.

We talked to senior author Nafissa Ismail, Associate Professor at the uOttawa School of Psychology and University Research Chair in Stress and Mental Health, to learn more about the findings.

Why did you and your team decide to investigate sleep and depression in adolescents?

"More than 264 million people around the world suffer from depression. It is a prevalent mood disorder that reduces our quality of life. Individuals diagnosed with depression experience several symptoms including general malaise, reduced libido, sleep disruptions and suicidal tendencies in severe cases.

Twice as many females as males are currently diagnosed with depression. Preliminary evidence suggests that Canadians are experiencing greater depressive symptoms this year, likely as a result of lifestyle changes due to the COVID-19 pandemic.

Adults with depression often first experience depressive symptoms in early adolescence. However, the causes underlying adolescent depression and its sex-specific prevalence rates remain unclear. A popular theory suggests that depression originates in adolescents overexposed to stress, and that differences between male and female depression rates are attributed to an increased female vulnerability to chronic stress.

Sleep disruption is a common stressor during adolescent development. Its repeated exposure could partially be responsible for adolescent female susceptibility to depression.

Using a mouse model, we investigated whether repeated sleep delays differentially affected male and female adolescent mice and examined how their response to stress changed."

How was the research conducted?

"80 adolescent and adult mice (40 males and 40 females) were manually sleep disrupted for the first four hours of each rest cycle or allowed normal rest for eight consecutive days. They were then exposed to a stressor to assess depression-like behavior."

What did you find?

"Our results showed that adolescent male and female mice both displayed significantly greater depressive behaviour after only 7 days of sleep delays while adult male and female mice did not show depressive behaviour under similar conditions.

When exposed to a new stressor following 7 days of repeat sleep delay, only adolescent male and female mice showed increased activity in the prelimbic cortex of the brain - not the adults. The prelimbic cortex is associated with stress coping strategies and can be damaged from overactivation following sleep deprivation.

Adolescent females also showed greater stress hormone release and activation of stress-sensitive brain cells than adolescent males following repeat sleep delay."

Why is it important?

"Our findings suggest that significant sleep delays during adolescence may increase the likelihood of depression onset in both males and females.

Additionally, sleep delay may sensitize adolescent females to other stressors and increase the likelihood of mood disorder development.

As COVID-19 quarantine requirements - such as remote learning, limited in-person social interactions and increased screen time - have removed some pressure to adhere to regular sleep schedules, adolescents could be at a higher risk than ever before for developing depression and other mood disorders."

A research team led by Tao Sun, associate professor of materials science and engineering at the University of Virginia, has made two discoveries that can expand additive manufacturing in aerospace and other industries that rely on strong metal parts.

Additive manufacturing has contributed to aircraft production for years, as reported by the Association for Manufacturing Technology. However, additive manufacturing also generates defects in the microstructure of a finished part, limiting its role to the fabrication of ductwork, interior components and other non-critical parts. Additive manufacturing of safety-regulated parts will help the industry achieve its aspirations for efficient and stable supply chain management, as well as fuel savings and emissions reductions that accompany a lighter aircraft.

Sun's team and collaborators have discovered why structural defects occur during the additive manufacture of parts made from a high-strength, light-weight titanium alloy widely used in aerospace applications. They present a process map--the blueprint the machine uses to create a part--to help manufacturers avoid generating defects during a common additive manufacturing technique called laser powder bed fusion.

The team's paper, Critical Instability at Moving Keyhole Tip Generates Porosity in Laser Melting, is published in the Nov. 27 issue of Science. Cang Zhao, who was a post-doc in Sun's research group at Argonne National Laboratory and now a faculty member in the Department of Mechanical Engineering at Tsinghua University in Beijing, first-authored the paper with colleagues from Argonne, Carnegie Mellon University, the University of Utah and UVA. The second author, Niranjan D. Parab, was also one of Sun's Argonne National Laboratory post-docs, who has since joined Intel.

The research team focused on the two most important conditions of the additive manufacturing process, laser power and scan speed. How these two conditions are set and interact is captured in a power-velocity process map. Similar to a conventional map, the power-velocity map sets boundary lines between areas in which to work and areas to avoid.

The power-velocity map can be divided into a good zone and three bad zones. If the manufacturer stays in the good zone, the build will likely yield a high-quality part on a consistent basis. Two of the bad zones are easy to recognize. One is represented by a lack of fusion, evidenced by unmelted powder because of deficient laser power density. A second bad zone is represented by balling, when a single printed line rolls up on itself, signaling that the laser is moving too fast.

Sun and the team focus on zone four. In this zone, parts come out of the build process with tiny holes, a structural defect called porosity. These tiny holes appear inside the material, making it hard to see and control. "You could print multiple test lines, and you still would not know by examining the part surface if porosity is occurring underneath," Sun said.

Porosity defects remain a challenge for fatigue-sensitive applications, such as aircraft wings. Some porosity is associated with deep and narrow vapor depressions called keyholes, which occur under high-power, low-scan-speed laser melting conditions.

Sun and the team discovered how porosity occurs and were able to characterize materials' transformation during the 3D printing process with very high spatial and temporal resolutions. They used an imaging technique, called high-speed synchrotron x-ray imaging, that monitors the formation of the pores frame-by-frame throughout the laser printing process. Images are captured at microsecond intervals, far beyond what the human eye can capture or the human brain can process.

High-speed synchrotron x-ray imaging is the only available method to qualitatively measure and describe what happens when the laser beam is exposed to the metal powder bed. In addition to melting powder, the laser also vaporizes some metal. The high-velocity vapor escaping the melt pool surface creates a small cavity called a keyhole.

The formation and size of the keyhole is a function of laser power and the materials' capacity to absorb laser energy. If the keyhole walls are stable, it enhances the surrounding material's laser absorption and improves laser manufacturing efficiency. If, however, the walls are wobbly or collapse, the material solidifies around the keyhole, trapping the air pocket inside the newly formed layer of material. This makes the material more brittle and more likely to crack under environmental stress.

Sun described the boundary between the good zone and the bad, porosity zone as smooth and sharp. "A very narrow laser condition, the specific combinations of power and speed, separates a good part and a part with pores. Just stepping across the line between the good and bad zones will determine whether your part carries this structural defect," Sun said. Based on the physics of such a smooth and sharp boundary, Sun knew that a subprocess was at play.

The team eventually discovered that the laser-metal interaction generates acoustic waves.

Sun explains that an acoustic wave can interact with a gas bubble in a liquid in different ways. Driven by the acoustic force, a bubble can move, deform, split and even collapse. In this study, the team found that under laser conditions near the porosity zone boundary, the acoustic force plays a critical role in pushing the pore away from the keyhole tip. Without the generation of acoustic waves in the melt pool, the pore will be pulled back to the keyhole.

"This is rather surprising," Sun said. "Short-pulse lasers were believed to be the source for generating acoustic waves in liquid, but we observed acoustic effects while using continuous-wave lasers. Apparently, there are still many intriguing problems that demand more research."

The two discoveries described in the Science paper have immediate impact on laser additive manufacturing of metals on both basic and applied research fronts. The well-defined porosity zone boundary in the power-velocity map provides more confidence for laser powder bed fusion practitioners to identify good printing conditions. Meanwhile, the new observations afforded by synchrotron x-ray imaging open up exciting multidisciplinary research areas that will attract more scientists to perform fundamental studies on laser additive manufacturing.

Sun's research team at UVA will continue to apply state-of-the-art characterization techniques for in-depth studies of additive manufacturing processes and materials. Additive manufacturing technologies hold the promise to completely revolutionize the way we make things.

"Additive manufacturing can only reach its full potential after the research community pieces together all the beautiful physics governing the complex energy-matter interactions involved in the printing process," Sun said.

The interaction between lasers and matter is at the forefront of new investigations into fundamental physics as well as forming a potential bedrock for new technological innovations. One of the initiatives spearheading this investigation is the Extreme Light Infrastructure Nuclear Physics (ELI-NP) project. Here the project's High-Power Laser System (HPLS) - the world's most powerful laser - is just one of the tools driving electron acceleration with lasers, Direct Laser Acceleration (DLA). In a new paper published in EPJ D, Etele Molnar, ELI-NP, Bucharest, and co-authors study and review the characteristics of electron acceleration in a vacuum caused by the highest-power laser pulses achievable today looking for the key to maximum net energy gain.

In particular, the authors calculate the optimal values of the laser beam required to achieve maximum electron energy for different laser power levels. They observe that tuning certain aspects of a laser such as its beam waist - the point at which a laser beam has its minimum radius - can favourably increase the maximum acceleration of electrons in a vacuum for both linearly and circularly polarised lasers.

As may be expected, Molnar and colleagues find that the net energy of the electrons, and thus their acceleration, is raised with increased laser power for beams with optimal beam waists. The paper describes an average energy gain in electrons of a few MeV in full pulse interactions, in which the highest energy electrons possess is roughly 160 MeV. In other cases such as half-pulse interactions, however, the authors say that these energy gains are almost an order of magnitude greater - reaching up to 1 GeV.

In terms of future research, the paper puts forward other potential directions. For example, the researchers suggest a study with a focus on direct laser acceleration with higher Laguerre Gaussian modes - circularly symmetric beam profiles or lasers with cavities that are cylindrically symmetric - should follow the current paper.

Under the current pandemic conditions, activities out in nature are a popular pastime. The beneficial effects of a diverse nature on people's mental health have already been documented by studies on a smaller scale. Scientists of the Senckenberg Gesellschaft für Naturforschung, the iDiv, and the University of Kiel now examined for the first time whether a diverse nature also increases human well-being on a Europe- wide scale.

To this end, the researchers used the data from the "2012 European quality of Life Survey" to study the connection between the species diversity in their surroundings and the life satisfaction in more than 26,000 adults from 26 European countries. Species diversity was measured based on the diversity of avian species, as documented in the European breeding bird atlas.

"Europeans are particularly satisfied with their lives if their immediate surroundings host a high species diversity," explains the study's lead author, Joel Methorst, a doctoral researcher at the Senckenberg Biodiversity and Climate Research Centre, the iDiv, and the Goethe University in Frankfurt. "According to our findings, the happiest Europeans are those who can experience numerous different bird species in their daily life, or who live in near-natural surroundings that are home to many species."

Birds are well-suited as indicators of biological diversity, since they are among the most visible elements of the animate nature - particularly in urban areas. Moreover, their song can often be heard even if the bird itself is not visible, and most birds are popular and people like to watch them. But there is also a second aspect that affects life satisfaction: the surroundings. A particularly high number of bird species can be found in areas with a high proportion of near-natural and diverse landscapes that hold numerous greenspaces and bodies of water.

"We also examined the socio-economic data of the people that were surveyed, and, much to our surprise, we found that avian diversity is as important for their life satisfaction as is their income," explains Prof. Dr. Katrin Böhning-Gaese, director of the Senckenberg Biodiversity and Climate Research Centre, professor at the Goethe University in Frankfurt am Main, and member of the iDiv. This result becomes particularly obvious when both values increase by ten percent. Fourteen additional bird species in the vicinity raise the level of life satisfaction at least as much as an extra 124 Euros per month in the household account, based on an average income of 1,237 Euro per month in Europe.

According to the study, a diverse nature therefore plays an important role for human well-being across Europe - even beyond its material services. At the same time, the researchers draw attention to impending health-related problems. "The Global Assessment 2019 by the World Biodiversity Council IPBES and studies of avian species in agricultural landscapes in Europe clearly show that the biological diversity is currently undergoing a dramatic decline. This poses the risk that human well-being will also suffer from an impoverished nature. Nature conservation therefore not only ensures our material basis of life, but it also constitutes an investment in the well-being of us all," adds Methorst in conclusion.

A study led by researchers at the National Institutes of Health has made a surprising connection between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), two disorders of the nervous system, and the genetic mutation normally understood to cause Huntington's disease.

This large, international project, which included a collaboration between the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institute on Aging (NIA), opens a potentially new avenue for diagnosing and treating some individuals with FTD or ALS.

Several neurological disorders have been linked to "repeat expansions," a type of mutation that results in abnormal repetition of certain DNA building blocks. For example, Huntington's disease occurs when a sequence of three DNA building blocks that make up the gene for a protein called huntingtin repeats many more times than normal. These repeats can be used to predict whether someone will develop the illness and even when their symptoms are likely to appear, because the more repeats in the gene, the earlier the onset of disease.

"It has been recognized for some time that repeat expansion mutations can give rise to neurological disorders," said Sonja Scholz, M.D., Ph.D., investigator, NINDS Intramural Research Program. "But screening for these mutations throughout the entire genome has traditionally been cost-prohibitive and technically challenging."

Taking advantage of technology available at NIH, the researchers screened the entire genomes from large cohorts of FTD/ALS patients and compared them to those of age-matched healthy individuals. While several patients had a well-established genetic marker for FTD/ALS, a small subset surprisingly had the same huntingtin mutation normally associated with Huntington's disease. Remarkably, these individuals did not show the classical symptoms of Huntington's but rather those of ALS or FTD.

"None of these patients' symptoms would have clued their physicians into thinking that the underlying genetic cause was related to the repeat expansion we see in Huntington's disease," said Dr. Scholz.

She continued by explaining that whole genome sequencing is changing how neurological patients can be diagnosed. Traditionally, this has been based on which disease best fit the overall symptoms with treatment aimed at managing those symptoms as best as possible. Now, clinicians can generate genetically defined diagnoses for individual patients, and these do not always align with established symptom-based neurological conditions.

"Our patients simply don't match a textbook definition of disease when it comes to which mutation produces which symptoms. Here we have patients carrying a pathogenic huntingtin mutation but who present with FTD or ALS symptoms," said Dr. Scholz.

One implication of these findings is that, if successful, these therapies could be applied to the small subset of FTD and ALS patients with that mutation as well. The researchers note that, while the number of FTD/ALS patients seen with the Huntington's-linked mutation is small (roughly 0.12-0.14%), adding genetic screening for the mutation to the standard diagnostic procedure for patients showing symptoms of FTD or ALS should be considered.

"Because gene therapy targeting this mutation is already in advanced clinical trials, our work offers real hope to the small number of FTD and ALS patients who carry this mutation," said Bryan Traynor, M.D., Ph.D., senior investigator, NIA Intramural Research Program. "This type of large-scale international effort showcases the power of genomics in identifying the molecular causes of neurodegenerative diseases and paves the way for personalized medicine."

Researchers from the Niels Bohr Institute, University of Copenhagen have, in collaboration with Norwegian researchers in the ERC Synergy project, ICE2ICE, shown that abrupt climate change occurred as a result of widespread decrease of sea ice. This scientific breakthrough concludes a long-lasting debate on the mechanisms causing abrupt climate change during the glacial period. It also documents that the cause of the swiftness and extent of sudden climate change must be found in the oceans.

Scientific evidence for abrupt climate change in the past finally achieved

During the last glacial period, app. 10,000 - 110,000 years ago the northern hemisphere was covered in glacial ice and extensive sea ice, covering the Nordic seas. The cold glacial climate was interrupted by periods of fast warmup of up to 16.5 degrees Celsius over the Greenland ice sheet, the so called Dansgaard Oeschger events (D-O).

These rapid glacial climate fluctuations were discovered in the Greenland ice core drillings decades ago, but the cause of them have been hotly contested. D-O events are of particular significance today as the rate of warming seems to be very much like what can be observed in large parts of the Arctic nowadays. The new results show that the abrupt climate change in the past was closely linked to the quick and extensive decline in sea ice cover in the Nordic seas. Very important knowledge as sea ice is presently decreasing each year.

"Our, up until now, most extensive and detailed reconstruction of sea ice documents the importance of the rapid decrease of sea ice cover and the connected feedback mechanisms causing abrupt climate change", says Henrik Sadatzki, first author of the study.

Sediment core and ice core data were combined in order to achieve the result

The Norwegian researchers investigated two sediment cores from the Norwegian sea and the Danish researchers investigated an ice core from East Greenland for changes in the sea ice cover. Both sediment and ice cores were meticulously dated and further linked to one another through several volcanic layers of ash (tephra) identified in both.

Past sea ice cover was reconstructed in the marine cores by observing the relation between specific organic molecules produced by algea living in sea ice and others by algea living in ice free waters. In the Renland ice core from East Greenland the researchers looked at the content of Bromin. This content is connected to newly formed sea ice, since Bromin contents increase when sea ice is formed. A robust chronology and sea ice information in both sediment cores and the ice core could be established and used to investigate the extent of the sea ice changes in the Nordic seas during the last glacial period.

"We have investigated how the sea ice cover changed during the last glacial period in both marine cores and ice cores. With the high resolution in our data sets we are able to see that the Nordic seas, during the rapid climate changes in the glacial period, change from being covered in ice all year round to having seasonal ice cover. This is knowledge we can apply in our improved understanding of how the sea ice decline we observe today may impact the climate in the Arctic", says Helle Astrid Kjær, Associate professor at the Ice, Climate and Geophysics section at the Niels Bohr Institute.

Sea ice changes in the past show how the climate today can change abruptly

The data the group of researchers present shows that the Nordic seas were covered by extensive sea ice in cold periods, while warmer periods are characterized by reduced, seasonal sea ice, as well as rather open ice free oceans. "Our records show that the extensive decline in sea ice could have happened during a period of 250 years or less, simultaneously with a phase in which the water in the oceans to the north mixed with the Nordic sea, and that this situation led to sudden changes in atmospheric warming", says Henrik Sadatzki.

As the Nordic seas changed abruptly from ice covered to open sea, the energy from the warmer ocean water was released to the cold atmosphere, leading to amplification of sudden warming of the climate. The result of the study documents that sea ice is a "tipping element" in the tightly coupled ocean-ice-climate system. This is particularly relevant today, as the still more open ocean to the north can lead to similar abrupt climate change.

What The Study Did: This survey study examines changes in the use of e-cigarettes by those 24 years old and younger during the COVID-19 pandemic.

Authors: Bonnie Halpern-Felsher, Ph.D., of Stanford University in Palo Alto, California, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2020.27572)

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

Mortality rates after cancer surgery declined for Black as well as white patients during a recent ten-year period, although the mortality gap between the two groups did not narrow, according to new research by Dana-Farber Cancer Institute, Brigham and Women's Hospital, and Harvard University investigators.

The findings, published online today by JAMA Network Open, present a mixed picture for healthcare policymakers: While postsurgical mortality rates have fallen for patients generally, more targeted efforts are needed to reduce disparities between Black and white patients undergoing such surgery, study authors say.

"Black Americans are likely to be diagnosed with more advanced cancer than whites and, historically, have had higher mortality rates following cancer surgery," says lead author Miranda Lam, MD, MBA, of Dana-Farber, Brigham and Women's Hospital, Harvard T.H. Chan School of Public Health, and Harvard Medical School. "Hospitals have put a variety of policies in place to improve surgical cancer care over the past 15 years. This study provided an opportunity to gauge the effects of those measures for patients in general and for Blacks and whites specifically."

Investigators used national Medicare data to examine the trends in mortality rates for the years 2007-2016 in Black and white patients who had undergone surgery for any of nine major types of cancer. (Racial group was determined by patients' self-identification in Medicare documentation.) The data covered 870,929 cancer operations in all.

The researchers found that national mortality trends following cancer surgery improved for Black and white patients by 0.12% and 0.14% per year, respectively. Because mortality rates for Blacks were higher to begin with than for whites, the equal decline in rates for both groups meant the gap between them did not shrink.

"The findings tell us that even though policies designed to improve cancer surgery outcomes are working better for all patients, none of them have been specific enough to close the gap in mortality between Blacks and whites," Lam remarks. "It's possible that part of the gap may be due to upstream and/or downstream issues from the surgery itself, such as late referrals which may lead to late presentation at time of surgery, fragmented follow-up after discharge, and limited resources in the community, and that different policies and interventions may be needed to address disparities in cancer surgery."

A new study further implicates low levels of the amino acid glycine in development of nonalcoholic fatty liver disease, or NAFLD. It also suggests addressing this might hold the key to a future treatment for the disease.

"We've uncovered a new metabolic pathway and potential novel treatment," says senior author Y. Eugene Chen, M.D., Ph.D., a professor of internal medicine and surgery, from the Michigan Medicine Frankel Cardiovascular Center. His team collaborated with researchers from the University of Michigan, Wayne State University and Technion-Israel Institute of Technology.

Chen says there is a large need to expand treatment options for patients with NAFLD. Although it's the most common chronic liver disease, there are currently no approved drugs to treat it.

Lead author Oren Rom, Ph.D., R.D., a research fellow at the Michigan Medicine Frankel Cardiovascular Center, says the team focused on the poorly understood relationship between dysregulated amino acid metabolism and NAFLD.

"In particular, lower circulating glycine is consistently reported in patients with NAFLD and related comorbidities including diabetes, obesity and cardiovascular diseases," Rom says. "Our studies not only offer a metabolic explanation for defective glycine metabolism in NAFLD, but also uncover a potential glycine-based treatment."

The researchers were able to improve body composition and several other measures in mouse models using a tripeptide known as DT-109.

"Glycine-based treatment attenuates experimental NAFLD by stimulating hepatic fatty acid oxidation and glutathione synthesis, thus warranting clinical evaluation," the authors write.