Culture

Artificial night-time lighting has a diverse range of effects across the natural world and should be limited where possible, researchers say.

A team led by the University of Exeter brought together more than 100 studies and found "widespread" impacts on animals and plants.

Changes to animals' bodies and behaviour - especially hormone levels and patterns of waking and sleeping - were consistently found.

The study shows that levels of melatonin (a hormone regulating sleep cycles) were reduced by exposure to artificial lighting at night in all animal species studied.

"Lots of studies have examined the impacts of artificial night-time lighting on particular species or communities of species," said Professor Kevin Gaston, of the Environment and Sustainability Institute on Exeter's Penryn Campus in Cornwall.

"Our research brings those studies together - and we find the effects are very diverse and very pervasive.

"Particularly strong responses are seen in hormone levels, the timing of daily activity in diurnal (daytime) species, and 'life-history' traits such as number of offspring.

"People may imagine this is all about powerful light, but in fact we are seeing a lot of responses at quite low levels of artificial light."

Dr Dirk Sanders added: "We see differences in nocturnal and diurnal species.

"For rodents, which are mostly nocturnal, the duration of activity tended to be reduced by night-time lighting.

"In contrast, for birds - with all of those included strictly diurnal - artificial light led to an extension of the duration of their activity, with singing and foraging starting earlier."

Previous studies have shown night-time lighting has wide-ranging impacts - from reducing pollination by insects to trees budding earlier in spring.

Like climate change, night-time lighting appears to benefit certain species in certain locations, but Professor Gaston said the clear message of the study was to reduce lighting where possible.

"Both climate change and night-time lighting are human-driven and enormously disruptive to the natural world," he said.

"Historically, we have not really worried about the impact of night-time lighting.

"Only now are we discovering its wide-ranging effects.

"Our study shows that we should, as a matter of principle, only use night-time lighting where we need it and no further, and at intensities that we need and no more.

"In effect, we need to view light like any other pollutant.

"Obviously it would be ridiculous to say 'switch the world's lights off' - but we could reduce our use of light immensely with absolutely no impact on ourselves."

Professor Gaston is the scientific advisor on a forthcoming landmark natural history series about the night-time, called "Earth at Night in Colour''. The series is released on Apple TV+ on December 4th.

Researchers at MIT and the University of Waterloo have developed a high-power, portable version of a device called a quantum cascade laser, which can generate terahertz radiation outside of a laboratory setting. The laser could potentially be used in applications such as pinpointing skin cancer and detecting hidden explosives.

Until now, generation of terahertz radiation powerful enough to perform real-time imaging and fast spectral measurements required temperatures far below 200 Kelvin (-100 degrees Fahrenheit) or lower. These temperatures could only be achieved with bulky equipment that limited the technology's use to a laboratory setting. In a paper published in Nature Photonics, MIT Distinguished Professor of Electrical Engineering and Computer Sciences Qing Hu and his colleagues report that their terahertz quantum cascade laser can function at temperatures of up to 250 K (-10 degrees Fahrenheit), meaning that only a compact portable cooler is required.

Terahertz quantum cascade lasers, tiny chip-embedded semiconductor laser devices, were first invented in 2002, but adapting them to operate far above 200 K proved to be so difficult that many people in the field speculated that there was a fundamental physical reason preventing it, Hu says.

"With a high operating temperature, we can finally put this in a compact portable system and take this breakthrough technology out of the laboratory," Hu says. "This will enable portable terahertz imaging and spectral systems that will have an immediate impact on wide-ranging applications in medicine, biochemistry, security, and other areas."

Hu began research into the terahertz frequencies -- a band of the electromagnetic spectrum between microwaves and the infrared range -- back in 1991.

"It took me 11 years and three generations of students to make our own [terahertz quantum cascade laser] in 2002," he says. Since then, maximum operating temperatures that limited the use of terahertz radiation remained well below room temperature. The maximum of 250 K reported in this paper represents a considerable jump from the previous maximum of 210 K, which was established in 2019, beating a previous 2012 record of 200 K that had stayed untouched for seven years.

The lasers, which measure only a few millimeters in length and are thinner than a human hair, are quantum well structures with meticulously custom-engineered wells and barriers. Within the structure, electrons "cascade" down a kind of staircase, emitting a light particle, or photon, at each step.

One important innovation described in the Nature Photonics paper was the doubling of the height of the barriers within the laser to prevent leakage of the electrons, a phenomenon that tended to increase at high temperatures.

"We understood that over-the-barrier electron leakage was the killer," causing the system to break down if not cooled with a cryostat, Hu says. "So, we put a higher barrier to prevent the leakage, and this turned out to be key to the breakthrough."

Previously, higher barriers were explored sporadically, but they yielded inferior results, Hu says. The prevailing opinion was that increased electron scattering associated with the higher barriers was detrimental, and therefore higher barriers should be avoided.

The research team developed the correct parameters for the band structure for tall barriers and a conceptually novel optimization scheme for the design.

This innovation was paired with a "direct phonon scheme" that keeps the laser operating through a configuration in which lower lasing levels of each module, or steps of the structure's staircase, are quickly depopulated of electrons through phonon (or a unit of vibrational energy) scattering into a ground state, which then serves as the injector of electrons into the next step's upper level, and the process repeats. Such an arrangement of the electrons in the system is essential for lasing to occur, as first envisioned by Einstein back in 1916.

"These are very complex structures with close to 15,000 interfaces between quantum wells and barriers, half of which are not even seven atomic layers thick," says co-author Zbig Wasilewski, professor of electrical and computer engineering and University of Waterloo Endowed Chair in Nanotechnology. "The quality and reproducibility of these interfaces are of critical importance to the performance of terahertz lasers. It took the best in molecular beam epitaxial growth capabilities -- our research team's key contribution -- together with our MIT collaborators' expertise in quantum device modeling and fabrication, to make such important progress in this challenging sector of THz photonics."

In a medical setting, the new portable system, which includes a compact camera and detector and can operate anywhere with an electric outlet, could provide real-time imaging during regular skin-cancer screenings or even during surgical procedures to excise skin cancer tissues. The cancer cells show up "very dramatically in terahertz" because they have higher water and blood concentrations than normal cells, Hu says.

The technology could also be applied in many industries where the detection of foreign objects within a product is necessary to assure its safety and quality.

Detection of gases, drugs, and explosives could become especially sophisticated with the use of terahertz radiation. For example, compounds such as hydroxide, an ozone-destruction agent, have a special spectral "fingerprint" within the terahertz frequency rage, as do drugs including methamphetamine and heroin, and explosives including TNT.

"Not only can we see objects through optically opaque materials, but we can also identify the substances," Hu says.

Hu says he sees "a clear path" to the goal of being able to generate powerful terahertz without needing a cooler.

"Using the direct phonon scheme and taller barriers is the way to go forward," he says. "I can finally see the light at the end of the tunnel when we will reach room temperature."

The digital age brims with promise for the world's half-billion smallholder farmers. Smartphones with the right apps can tell farmers when it's likely going to rain, how to identify and eradicate pests, and negotiate the prices for a bountiful harvest delivered by a combination of hard work and big data.

While digital technologies are steadily reaching more farmers, for each one plugged into the latest weather forecast or selling produce at the tap of a screen, millions more are sidelined as the digital revolution whizzes by.

Depending on the region, this is due to a lack of devices or a combination of nonexistent, extremely expensive or outdated network coverage. For example, across Mexico, Latin America's second-largest economy, virtually everyone has a cell phone but only 25% of farming households have internet access.

Across many locations in sub-Saharan Africa, which has the potential to be a global breadbasket, fewer than 40% of farming households have internet access. And unlike Asia and Latin America where mobile phone ownership is nearly universal, fewer than 70% of farmers in sub-Saharan Africa have handheld devices. And access to 4G networks required to run more sophisticated apps is only 9%.

"There's an assumption that we're going to be able to target everyone with these new technologies and everyone is going to be able to benefit," said Zia Mehrabi, a scientist at the University of British Columbia who led the analysis published Nov. 2 in Nature Sustainability.

The study also showed major differences between farm size and mobile network services. Globally, 24-37% of farms under one hectare had access to 3G or 4G networks. Service availability is as high as 80% for farms over 200 hectares.

2G technology, which provides voice and text service, has wider availability but is not compatible with most smartphone technology.

"We face a digital poverty trap - those who are already marginalized fall further behind while others benefit from the myriad of opportunities offered by digital innovation in farming," said Andy Jarvis, a co-author from the Alliance of Bioversity International and CIAT, who is also part of the CGIAR Platform for Big Data in Agriculture.

The researchers' affordability analysis found that for many rural poor who do live in areas with coverage, getting connected could eat up the majority of their household budget.

"The study points to the need not only to expand coverage but vastly reduce the costs to make it affordable," said Jarvis. "We need to consider digital connectedness as a basic need, and design next-generation innovations to work in every corner of Africa."

The study included authors from the World Bank and the Helmholtz Centre for Environmental Research in Germany.

Noise but no signal

The study zeroed in on mobile coverage gaps where farmers need it most.

In nitrogen-deficient cropping areas, which have low yields without proper fertilizer management, 3G/4G availability was 60% and 22% respectively. Areas dependent on rainfall for production had 71% and 54% availability. For arid environments, which pose large but surmountable production challenges, coverage was only 37% and 17%.

"These coverage gaps pose important roadblocks for developing data-hungry nutrient advisories, climate services, and financial services that require mobile internet," the authors said.

As for people affected by food insecurity, which is based on the prevalence of childhood stunting, 3G/4G coverage was 61%/45% and, in Africa, 52%/22%. Global access for people afflicted by malaria, which caused more than 400,000 deaths in 2018, is only 37%/17%.

"This lack of coverage for at-risk populations poses serious concern for responding to food security and health impacts of emerging diseases including COVID-19. This lack of coverage is more problematic today than ever before," said Mehrabi.

Universal broadband

The authors call on governments, businesses, development agencies and global philanthropists to quickly mobilize the investments and interventions needed to close the digital divide. They call for immediate action on The United Nations Sustainable Development Goal, which outlines universal access to the Internet in least developed countries by 2020.

Proposed actions include:

Investment in "last-mile" infrastructure innovations such as renewable energy, low-cost mobile towers, and backhaul technologies like scalable microwave technologies.

Increase in handset affordability: devices in emerging markets are in the USD $100 range, making them unaffordable for many, including women who have lower handset ownership than men in many regions.

Make data access universal: even if they have handsets, the poorest farmers are unable to afford data. In some African countries, a basic plan with 1GB of data per month exceeds the annual income of the poorest 10% of the population.

Use interim solutions: SMS advisories and voice message services on existing 2G networks offer significant opportunities for productivity, market connectivity, money transfers, credit and other services - as long as they have sophisticated back-end support.

Research funding: this baseline study should be regularly updated to keep track of progress and build metrics related to capacity building, skills, digital literacy and cultural appropriateness of services, particularly across ages and genders.

"There's a lot of 5G coming online. If access is not addressed at lower-end technologies, this is only going to aggravate the divide and create more inequality," said Mehrabi.

While the future may hold universal internet access for the world - Google's Loon, OneWeb and SpaceX's Starlink hope to enable this - the reality is that delivery of these products is still perhaps a long way off.

"They'd better get their skates on, because we desperately need universal access in farming landscapes. And the longer we delay, the more problematic this is going to be," said Mehrabi.

The fabled Silk Road - the 4,000-mile stretch between China and Western Europe where trade flourished from the second century B.C. to the 14th century A.D. - is responsible for one of our favorite and most valuable fruits: the domesticated apple (Malus domestica).

Snack-packing travelers would pick apples at one spot, eat them and toss their cores many miles away. The seeds grew into trees in their new locations, cross-bred with the wild species, and created more than 7,000 varieties of apples that exist today.

Hybridizations with wild species have made the apple genome very complex and difficult to study. A global team of multi-disciplinary researchers - co-led by Zhangjun Fei, faculty member at Boyce Thompson Institute (BTI), and Gan-Yuan Zhong, scientist with the USDA-Agricultural Research Service (ARS) in Geneva, New York - tackled this problem by applying cutting-edge sequencing technologies and bioinformatics algorithms to assemble complete sets of both chromosomes for the domesticated apple and its two main wild progenitors.

The researchers discovered that the apple's unique domestication history has led to untapped sources of genes that could be used for crop improvement, such as improving size, flavor, sweetness and texture.

"Plant breeders could use this detailed information to improve upon traits that matter most to consumers, which today is primarily flavor," says Fei, also an adjunct associate professor in Cornell University's School of Integrative Plant Science (SIPS).

"Perhaps more importantly," he added, "the information will help breeders produce apples that are more resistant to stress and disease."

The research is described in a paper published in Nature Genetics on November 2, with authors from BTI, Cornell University, Cornell AgriTech, the U.S. Department of Agriculture (USDA) and Shandong Academy of Agricultural Sciences.

From the Silk Road to Geneva, N.Y.

According to Fei, the new study was the outgrowth of an earlier collaboration, published in Nature Communications in 2017, which traced the history of apple domestication and evolution along the Silk Road.

Follow-up discussions among Fei, Zhong and other colleagues at Cornell, inspired them to build better and new apple reference genomes by applying new sequencing and assembly technologies to material in USDA's Geneva Clonal Repository. The repository, which is housed at Cornell AgriTech, holds the largest collection of apple accessions in the world. Many of these accessions can be traced back to the Silk Road.

In the current work, the researchers sequenced, assembled and compared the full reference genomes for three species: Gala, a top commercial cultivar of M. domestica; and apple's two main wild progenitors, the European crabapple (M. sylvestris) and the central Asian wild apple (M. sieversii), which together account for about 90% of the domesticated apple's genome.

The results provide apple breeders with detailed genomic roadmaps that could help them build a better apple.

"We wanted to develop new genomes, especially the wild progenitors, because of the tremendous impact they could have on understanding apple's genetic diversity and identifying useful traits for breeding new cultivars," said Zhong, who is also an adjunct associate professor in SIPS.

By comparing the three genomes, the researchers were able to identify which progenitor species contributed the genes responsible for many traits in the domesticated apple.
For example, the team found that the gene giving apple its crunchy texture is located near the gene that makes it susceptible to blue mold.

"Now that we know exactly where those two genome regions are," Fei said, "breeders could figure out a way to keep the texture gene and breed out or edit out the blue mold gene to produce a more disease-resistant cultivar."

Discovering what's missing

The team also assembled pan-genomes for the three species. A pan-genome captures all of the genetic information in a species, unlike a reference genome that captures one individual organism. Pan-genomes are especially important for a very diverse species like apple.

The team identified about 50,000 genes in the pan-genome of the domesticated apple, including about 2,000 that were not present in previously published reference genomes for apple species. "These 'missing genes' turn out to be really important, because many of them determine the traits of greatest interest to apple breeders," Fei said.

Using RNA extracted from different stages of Gala fruits, they also identified genes linked to texture, aroma and other fruit characteristics that were preferentially expressed between the two copies of the genes.

"That provides us and breeders with an even deeper understanding of the genetic diversity underlying a particular trait," Zhong said.
"The findings will help our group better manage and curate more than 6,000 apple accessions in the USDA Geneva Clonal Repository," Zhong adds, "as well as enable us to provide critical genetic and genomic information associated with the accessions to breeders and other researchers."

UNIVERSITY PARK, Pa. -- As health care costs balloon in the U.S., experts say it may be important to analyze whether those costs translate into better population health. A new study led by a Penn State researcher analyzed existing data to find a dividing line - or "threshold - for what makes a treatment cost-effective or not.

David Vanness, professor of health policy and administration, led a team of researchers that created a simulation to consider health care treatment costs, insurance premiums, quality of life, and life expectancy to explore whether a treatment delivers enough value for its costs to be considered beneficial for population health.

According to Vanness, the term "treatment cost" in this research incorporates all the costs and savings related to a treatment. For example, the cost of a treatment to lower blood cholesterol would include how much it costs but also take into account potential savings for preventing a heart attack and its subsequent treatment.

"We know that we are spending more and more on health care in the U.S. and that we're getting less and less for it," Vanness said. "We do a good job of developing new treatments in this country, but we don't do a good job of covering everybody or making sure that people have access to basic health care. We're spending a lot on our medical treatments, but many of those treatments just don't have a lot of value."

Vanness added that in order to improve a population's health without spending too much, it's important to be able to tell whether the prices drug and device manufacturers are charging are justified by what they deliver in health improvements.

The researchers found that in their simulation, for every $10,000,000 increase in health care expenditures, 1860 people became uninsured. This led to five deaths, 81 quality-adjusted life-years lost due to death, and 15 quality-adjusted life-years lost due to illness. In health care economics, one quality-adjusted life-year (QALY) is equal to one year of perfect health.

Vanness said these results -- recently published in the Annals of Internal Medicine -- suggests a cost effectiveness threshold of $104,000 per QALY.

"If a treatment is beneficial but it costs more than about $100,000 to gain one quality-adjusted life-year using that treatment, then it may not be a good deal," Vanness said. "Because our simulation was using data estimates, we wanted to come up with a range of plausible values. So anything over a range of $100,000 to $150,000 per QALY gained is likely to actually make our population's health fall."

To create the simulation, Vanness said he and the other researchers used a variety of data, starting with estimates about how likely people are to drop their insurance when their premiums go up.

"We also used evidence from the public health literature on what happens to people's health and mortality when they gain or lose health insurance," Vanness said.

The simulation then compiled that data and estimated how much the health of a population goes down when costs increase. According to Vanness, that relationship determines the cost-effectiveness threshold -- how much a treatment can cost relative to the health benefits it gives before it causes more harm than good.

The researchers said the findings could be especially important to organizations like the Institute for Clinical and Economic Review, which provides analysis to several private and public insurers to help negotiate prices with manufacturers. These organizations could use the findings as empirical evidence for what makes a treatment a good value in the U.S.

"Moving forward, I think some changes could be made to national policy to make cost effectiveness analysis more commonly used," Vanness said. "Our goal is to get that information out there with the hope that somebody is going to use it to help guide coverage or maybe get manufacturers to reduce their prices on some of these drugs."

CHICAGO (November 2, 2020): Firearm violence impacts not only individuals and their communities, but also the health care providers who treat them. For surgeons, treating these victims and understanding the impact of firearm violence as a public health issue requires both technical and non-technical skills. Researchers at Washington University School of Medicine, St. Louis, Mo., developed a multidisciplinary curriculum to train surgical residents so that they can best treat victims of firearm violence and feel confident in contributing to the national conversation on firearm violence as a public health problem. The study findings appear as an "article in press" on the Journal of the American College of Surgeons website ahead of print.

The Anatomy of Gun Violence (AGV) curriculum was developed at Washington University School of Medicine to teach surgical trainees about managing firearm injuries while also understanding the injuries within the context of the public health epidemic of firearm violence. To achieve these goals, the curriculum was delivered over six weeks to general surgery residents in the 2017-18 and 2018-19 academic years. The curriculum contains multiple educational methods: a core curriculum of didactic lectures, mock oral examinations, a bleeding control training session, a Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) training session, a gun violence survivor session, and the Surgery for Abdominal-thoracic ViolencE (SAVE) simulation lab, along with other specialty programs. The authors believe this is the first effort to teach surgical residents about firearm violence as a disease process within its social context.

"We wanted to create a more holistic curriculum that not only involved epidemiological aspects of firearm violence, but also preventative medicine and the impact it has on the emotional and psychosocial parts of our lives," said lead study author Emily J. Onufer, MD, MPH, a general surgery resident at Washington University School of Medicine.

In both academic years, 60 surgical residents participated in the AGV curriculum and 41 and 36 residents, respectively, completed a survey regarding their experiences with the curriculum. The residents reported an average 7.5 percent improvement in knowledge, with junior residents showing an even larger increase. The SAVE lab, where residents are grouped in teams and complete five penetrating trauma scenarios, was the highest rated component of the curriculum. Respondents also requested a debrief after the SAVE lab to discuss best practices and a session on firearm safety, policy, and opportunities for advocacy so that they can feel confident contributing to the national conversation on firearm violence.

Dr. Onufer and her coauthors emphasized the importance of the gun violence survivor session in the curriculum. She said that surgeons have the tendency to, as a coping mechanism, depersonalize the treatment of firearm violence victims. The survivor session helped humanize and personalize the firearm violence epidemic in St. Louis.

"One of the hardest things for surgical residents is that we see these patients and we do everything we can to help them, but then we may rotate off the service and we don't find out what happens to them," said study coauthor Erin Andrade, MD, MPH, a general surgery resident at Washington University School of Medicine. "Bringing a patient back through the gun violence survivor session meant getting to hear a story come full circle. The survivor was able to come back and show us the impact we can make in a patient's life."

The AGV curriculum also contained a section on STOP THE BLEED®, training residents with hands-on practice of direct manual pressure, tourniquet application, and wound packing to stop severe bleeding. Residents assembled their own bleeding control kits during the training and, in their second year, if they had previously completed the STOP THE BLEED® session, they had the opportunity to serve as an instructor for a session with hospital environmental services workers. Serving as an instructor gave residents the chance to teach lifesaving skills to members of their community.

"The surgeon is relevant to the public health experience of violence. We can have an impact outside the operating room. I think a lot of residents who maybe never saw that possibility before now believe that," said study coauthor LJ Punch, MD, FACS, president, Power4STL, St. Louis, Mo.

Each scenario in the AGV curriculum represented actual patients who had been treated at the trauma center. Each scenario also was named after the residents who were involved in the care of that patient. Naming each scenario in this manner highlighted the tremendous impact surgical trainees have on the lives of firearm violence victims.
"I went through the operative records and found the names of the residents who were taking care of the patient from the emergency room to the operating room and I named the case after them. That is not something residents often get feedback on--that their work is the reason why this person is alive," Dr. Punch said.

The researchers are exploring ways to track the curriculum's clinical impact beyond the six-week course. They noted this is a single center experience at an urban training program with a high prevalence of firearm injuries, which could limit the curriculum's applicability in other regions. However, they emphasized that firearm violence is an epidemic across the U.S. and this curriculum provides a way to standardize the teaching of penetrating traumatic injury for surgical trainees.

Addressing firearm violence from a public health approach is also the focus of the American College of Surgeons Improving Social Determinants to Attenuate Violence (ISAVE) task force, which recently outlined steps the medical community must take to understand and address the root causes of firearm violence.

In nature, healthy plants are awash with bacteria and other microbes, mostly deriving from the soil they grow in. This community of microbes, termed the plant microbiota, is essential for optimal plant growth and protects plants from the harmful effects of pathogenic microorganisms and insects. The plant root microbiota is also thought to improve plant performance when nutrient levels are low, but concrete examples of such beneficial interactions remain scarce. Iron is one of the most important micronutrients for plant growth and productivity. Although abundant in most soils, iron's poor availability often limits plant growth, as it is found in forms that cannot be taken up by plants. Thus, adequate crop yields often necessitate the use of chemical fertilizers, which can be ecologically harmful in excessive application. Now, MPIPZ researchers led by Paul Schulze-Lefert have uncovered a novel strategy employed by plants to overcome this problem: they release substances from their roots that direct plant-associated bacteria to mobilise soil iron so that plants can easily take it up.

When confronted with iron in unavailable forms, plants mount a compensatory response to avoid iron deficiency. This starvation response involves extensive reprogramming of gene expression and the production and secretion of coumarins, aromatic compounds that are discharged from plant roots and which themselves can improve iron solubility. Interestingly, it was recently shown that coumarins are a selective force, shaping the composition of plant-associated bacterial communities. Now, it emerges that some coumarins also act as an "SOS" signal that prompts the root microbiota to support plant iron nutrition.

To first assess the contribution of the root microbiota to iron-limiting plant performance, first-author Christopher Harbort and colleagues used a controlled system which allowed them to regulate the availability of iron as well as the presence of root-associated bacteria. Using the laboratory model thale cress, they compared plants completely lacking bacteria and ones with an added synthetic community (SynCom) of bacterial commensals which reflects the root bacterial diversity observed in nature. The authors found that addition of this bacterial SynCom strongly improved the performance of plants grown on unavailable iron but not those grown with iron that was readily available. Growing plants in associations with single bacterial strains allowed them to determine that this iron-rescuing capacity is widespread among bacteria from different bacterial lineages of the root microbiota. When the researchers performed the same experiments with plants compromised in the production or secretion of coumarins, the community of bacteria provided no benefits. Thus, they could show that plant-secreted coumarins are responsible for eliciting nutritional assistance from bacterial commensals under iron limitation.

The authors' findings strongly suggest that the root microbiota is an integral part of how plants adapt to growth in iron-limiting soil. Furthermore, by identifying the plant-to-microbe signal for assistance, this research brings us one step closer to harnessing naturally present soil bacteria as a substitute for synthetic fertilizers. Improving plant iron nutrition could not only improve agricultural yields, but also increase the nutrient content of staple food crops, a potential strategy for tackling iron deficiency in humans as well.

Although profoundly different in terms of physiology, habitat and nutritional needs, plants and animals are confronted with one shared existential problem: how to keep themselves safe in the face of constant exposure to harmful microorganisms. Mounting evidence suggests that plants and animals have independently evolved similar receptors that sense pathogen molecules and set in motion appropriate innate immune responses. Now, in a study just published in the journal Cell Host & Microbe, senior author Takaki Maekawa together with co-first authors Lisa K. Mahdi, Menghang Huang, Xiaoxiao Zhang and colleagues have discovered that plants have evolved a family of proteins that bear a striking resemblance to proteins called mixed lineage kinase domain-like proteins (MLKLs), which trigger cell death in vertebrates as part of the immune response. In uncovering and characterizing an important new family of plant immune proteins, the authors' study, which involved collaboration with fellow MPIPZ researchers Paul Schulze-Lefert, Jane Parker and Jijie Chai, provides intriguing new insights into how plants protect themselves from microbial invaders.

Regulated cell death often accompanies immunity against infection in plants, animals and fungi. One pervasive theory suggests that highly localised cell death responses serve to strictly limit the spread of infection. Although starting from independent origins this shared response seems to also involve highly similar machinery: many proteins involved in cell death in different kingdoms of life contain a so-called HeLo domain, a bundle structure made up of four helices, which causes resistance and cell death by disturbing the integrity of cellular membranes or forming ion channels.

Based on the similarities between animal and plant immune systems and on the key role played by HeLo domains in cell death, Maekawa hypothesised that plants might also contain other proteins with HeLo domains. Making use of bioinformatic and structural analysis, he and his team discovered a new family of HeLo domain-containing proteins that are widely shared among different plant species, indicating that they are important for plant physiology.

Maekawa termed the proteins plant MLKLs, and for further studies he focused on MLKLs expressed in the model plant Arabidopsis thaliana. He and his team isolated MLKL proteins from A. thaliana and determined that plant MLKLs possess the same overall protein architecture as their vertebrate counterparts and also assemble into tetramer, likely auto-inhibited, structures when they're not active. Importantly, plant MLKLs also play a role in immunity, as plants in which genes encoding these proteins were mutated and thus non-functional were susceptible to pathogen infection.

Further investigation revealed additional similarities with vertebrate MLKLs: plant MLKLs are also trafficked to cellular membranes as part of their function, and activation of these proteins leads to cell death. Maekawa now aims to discover the molecular details underlying the function of plant MLKLs in immunity: "It will be exciting to uncover exactly how MLKLs are activated upon pathogen infection and how this activation is translated into effective plant protection."

The period of time before pregnancy is critically important for the health of a woman and her infant, yet not all women have access to health insurance during this time. New research finds that the expansion of Medicaid for many states under the Affordable Care Act (ACA) had a positive impact on a variety of indicators of maternal health prior to conception.

The study in the journal Health Affairs, conducted by Laura R. Wherry, assistant professor of economics and public service at the Robert F. Wagner Graduate School of Public Service, New York University, Rebecca Meyerson of the University of Wisconsin, Madison, and Samuel Crawford of the University of Southern California, Los Angeles, compared changes in 10 major preconception health indicators for low-income women in both expansion and non-expansion states following the ACA Medicaid expansions.

The researchers found significant improvements in three preconception health indicators associated with the Medicaid expansions:

Increase in preconception health counseling, which provides a valuable opportunity to address key risk factors associated with adverse maternal and infant health outcomes prior to conception.

Increase in daily folic acid intake prior to pregnancy, which is recommended for all women by the U.S. Preventive Services Task Force to reduce the likelihood of neural tube defects among newborns.

Increased use of effective birth control methods after childbirth, which may decrease the likelihood of unplanned pregnancies or short interpregnancy intervals.

They did not find evidence of changes in chronic condition prevalence or health behaviors.

As of October 2020 - ten years after the landmark passage of the ACA, a total of 36 states and the District of Columbia have implemented the expansion of the Medicaid expansion program and healthcare access for the poor.

"We hope these findings can be used to help address some of the risk factors that shape maternal and child health in the U.S.," said Professor Wherry.

Okazaki, Japan -- In baseball, a batter's reaction when he swings and misses can differ depending on whether they were totally fooled by the pitch or simply missed the change-up they expected. Interpreting these reactions is critical when a pitcher is deciding what the next pitch should be. This type of socially interactive decision-making is the topic of a recent brain study led by Masaki Isoda at the National Institute for Physiological Sciences (NIPS) in Japan. They found that this ability requires a specific connection between two regions in the front of the brain, and that without it, monkeys default to making decisions as if they were playing against an inanimate object.

Two regions in the front of the brain--the PMv and the mPFC--contain "self", "partner", and "mirror" neurons that signal self-actions, other-actions, or both, respectively. Scientists believe that these types of neurons are what make social qualities such as empathy possible. However, despite years of research, not much is known about how these brain regions work together. The NIPS team set out to find some answers.

They trained monkeys to play a game with a partner in which they pressed buttons to obtain rewards. Sometimes, the rules of the game changed, and the monkeys made mistakes. Sometimes monkeys made mistakes simply because they were careless. "Monkeys continued using the same rule if they thought the other monkey's mistakes were accidental," says Masaki Isoda. "But, if they thought the mistakes were because the rules had changed, the monkeys adjusted their thinking and switched rules." The researchers included three types of partners: real monkeys, recorded monkeys, and inanimate objects.

They found that the proportion of partner cells was much higher in the mPFC than in the PMv, indicating it could be particularly important for understanding what others are thinking. Partner cells in the mPFC were most active and most affected by the PMv when partners were real and least active and least affected when they were inanimate objects. Thus, it seemed possible that the ability of a monkey to recognize social cues depends on mPFC cells getting social information from the PMv.

To test this hypothesis, the researchers used viral vector technology to temporally silence only neurons in the PMv that connect to the mPFC. In this situation, monkeys made many more mistakes after their partners made careless errors, behaving as if every error was because the rules had changed. "This behavior was reminiscent of an autistic monkey who played the same game," says Taihei Ninomiya. "As difficulty understanding social cues is a hallmark of autism, understanding the role of the PMv-mPFC pathway provides a good direction for future research into autism spectrum disorders."

Scientists at Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST) and colleagues have uncovered some of the complex molecular mechanisms involved in the formation of the brain's neural circuits. Their findings were published in The Journal of Neuroscience and could be relevant for developing treatments for diseases, such as autism spectrum disorders and schizophrenia.

Synaptogenesis is a complex molecular process that promotes the growth and development of nerve fibre ends so they can recognize and communicate with their appropriate nerve fibre partner via molecules transmitted across specialized junctions, called synapses.

"A comprehensive understanding of synaptogenesis is essential for designing therapeutic approaches against many devastating brain disorders," says DGIST neuroscientist, Professor Jaewon Ko. "So it's really crucial to develop fine-tuned molecular manipulations that can target key synapse components in order to understand their roles."

Professor Ko and his team of scientists specifically looked at two key 'synaptic adhesion molecules' involved in synaptogenesis. Neurexins and leukocyte common antigen-related protein tyrosine phosphatases (LAR-RPTPs) are transmembrane proteins that are located on the 'presynaptic' sending side of a developing nerve junction. They are known to be involved in the formation and maintenance of synapses. But it has been unclear whether they cooperate with each other and how they interact with other synaptic molecules in regulating synapse organization.

To address these questions, the scientists conducted a series of extensive experiments in rodent nerve cell cultures and then in fruit flies in which Drosophila orthologs of neurexins and LAR-RPTPs were deleted. They observed that two members of LAR-RPTPs (termed PTPσ and PTPδ) are required for neurexins to promote presynaptic differentiation. At the sending end of the developing synapse, neurexins bind to either of the two LAR-RPTPs through a distinct set of molecules depending on whether the synapse will be excitatory or inhibitory; in other words if it will send signals to activate or to turn off its receiving nerve end.

The scientists also found that PTPσ and neurexin directly interact through specific glycans, called heparan sulphates, to direct the formation of the receiving nerve end at excitatory synapses.

"We believe that our findings have significance in terms of proposing a novel molecular model underlying synapse organization, and possibly have implications for understanding neural circuit architecture and brain functions," says Professor Ko.

The team is now investigating downstream mechanisms underlying interactions of neurexins with LAR-RPTPs in vertebrate neurons, and is working to pinpoint a set of intracellular proteins involved in trans-synaptic signalling in presynaptic neurons. Further studies are essential before these findings can be translated into clinical studies.

Banning a harmful ingredient from the Australian food supply could prevent thousands of deaths from heart disease according to new research from The George Institute for Global Health.

Trans fatty acids - made during the industrial process that converts vegetable oils into a solid form of fat - are a well-known risk factor for heart disease. But it has been argued that eliminating them completely - as required by law in many overseas countries - would be too costly for both government and the food industry.

Dr Jason Wu, Program Head of Nutrition Science at The George Institute said that while the intake of trans fatty acids in Australia is generally low, levels continue to exceed health guidelines for some people, mostly those with less education and income.

"Despite the known health risks, our previous research shows progress on reducing trans fats in Australia's packaged food supply has slowed to a halt," he said.

While trans fats occur naturally at low levels in meat and cow's milk, people in most countries can also get them from partially hydrogenated vegetable oils in processed foods such as pastries. But avoiding them isn't easy because in Australia, it's not compulsory for manufacturers to list the amount of trans fats on the nutrition information panel on packaged foods.

Researchers from The George Institute for Global Health set out to calculate the potential costs and health benefits of a nationwide ban on industrial trans-fatty acids in Australia food supply.

The modelling study found that such a ban could prevent around 2,000 deaths and 10,000 heart attacks over the first ten years and up to 42,000 deaths from heart disease over the lifetime of the adult population (the time from when the ban starts to when all individuals died or reached 100 years of age).

The cost of implementing this legislative measure was estimated to be A$22 million during the first ten years and A$56 million over the population lifetime, most of which was down to government costs for monitoring implementation of the ban.

However, the estimated heart disease-related healthcare cost savings, compared to no ban, reached A$80 million over ten years and A$538 million over a lifetime.

Overall, the elimination of trans fatty acids in Australia was estimated to be cost-saving to highly cost-effective during the first ten years, and highly cost-effective over the population lifetime.

Lead author and Senior Research Fellow at The George Institute Dr Matti Marklund said the results supported the call by the WHO to eliminate trans fats from the food supply around the world.

"Our modelling study suggests that even in countries like Australia where intake is low, elimination of industrial trans-fatty acids can improve public health," he said.

"We also found that socioeconomically disadvantaged groups and Australians outside major cities could potentially have the greatest health gains from such legislation."

In the meantime, in order to minimise your intake of trans fatty acids Dr Marklund advised checking the labels of the packaged foods before buying.

"Any products that include partially hydrogenated fat or partially hydrogenated vegetable oil on the ingredient list are more likely to contain trans fats," he said.

Osaka, Japan - A research team from Osaka University has developed an innovative new animal-borne data-collection system that, guided by artificial intelligence (AI), has led to the witnessing of previously unreported foraging behaviors in seabirds.

Bio-logging is a technique involving the mounting of small lightweight video cameras and/or other data-gathering devices onto the bodies of wild animals. The systems then allow researchers to observe various aspects of that animal's life, such as its behaviors and social interactions, with minimal disturbance.

However, the considerable battery life required for these high-cost bio-logging systems has proven limiting so far. "Since bio-loggers attached to small animals have to be small and lightweight, they have short runtimes and it was therefore difficult to record interesting infrequent behaviors," explains study corresponding author Takuya Maekawa.

"We have developed a new AI-equipped bio-logging device that allows us to automatically detect and record the specific target behaviors of interest based on data from low-cost sensors such as accelerometers and geographic positioning systems (GPS)." The low-cost sensors then limit the use of the high-cost sensors, such as video cameras, to just the periods of time when they are most likely to capture the specific target behavior.

The use of these systems in combination with machine learning techniques can focus data collection with the expensive sensors directly onto interesting but infrequent behaviors, greatly increasing the likelihood that those behaviors will be detected.

The new AI-assisted video camera system was tested on black-tailed gulls and streaked shearwaters in their natural environment on islands off the coast of Japan. "The new method improved the detection of foraging behaviors in the black-tailed gulls 15-fold compared with the random sampling method," says lead author Joseph Korpela. "In the streaked shearwaters, we applied a GPS-based AI-equipped system to detect specific local flight activities of these birds. The GPS-based system had a precision of 0.59—far higher than the 0.07 of a periodic sampling method involving switching the camera on every 30 minutes."

There are many potential applications for the use of AI-equipped bio-loggers in the future, not least the further development of the systems themselves. "These systems have a huge range of possible applications including detection of poaching activity using anti-poaching tags," says Maekawa. "We also anticipate that this work will be used to reveal the interactions between human society and wild animals that transmit epidemics such as coronavirus."

New research from north-west England published in Anaesthesia (a journal of the Association of Anaesthetists) shows that during the first wave of COVID-19, the proportion of caesarean section deliveries carried out under general anaesthesia approximately halved, from 7.7% to 3.7%. This lower rate of general anaesthesia (also 3.7%) was also found among the small number of women having caesarean sections who had tested positive for COVID-19.

"At the onset of the global pandemic of COVID-19 (SARS-CoV-2), guidelines recommended using regional anaesthesia for caesarean section in preference to general anaesthesia, in order to reduce the risk of SARS-CoV-2 infection in healthcare workers," say the authors, who include Dr Kailash Bhatia, Saint Mary's Hospital (part of Manchester University NHS Foundation Trust), and The University of Manchester; Dr Malachy Columb, Wythenshawe Hospital (part of Manchester University NHS Foundation Trust), UK, and colleagues. "Anaesthetic decision-making, recommendations from these anaesthetic guidelines, and the regular presence of an on-site anaesthetic consultant in the delivery suite throughout the first wave could be among the key factors that influenced this decline."

National figures from the UK show that almost 170,000 caesarean sections were carried out in 2016-17 and approximately 8.75% (around 15,000) were performed under a general anaesthetic. In this new study, the authors explored whether general anaesthesia rates for women having caesarean sections changed during the peak of the pandemic across six maternity units* in the north-west of England.

They analysed data for 2480 caesarean sections across these six maternity units* from 1 April to 1 July 2020 and compared this information with data from 2555 caesarean sections performed at the same hospitals over a similar period in 2019.

The data revealed a significant reduction (7.7% to 3.7%) in general anaesthetic rates for women having caesarean sections, with analysis showing that a woman having a caesarean section birth during this period in 2020 was half as likely to have it under general anaesthetic than a woman having the procedure in 2019. The authors also found that the rate of conversion from local to general anaesthesia (done for emergency reasons during the procedure) also halved from 1.7% to 0.8% from 2019 to 2020.

Their analysis found no differences between 2019 and 2020 for the obstetric indications for caesarean sections. However, the overall rate of caesarean sections in all births in these samples increased from 28.3% in 2019 to 29.7% in 2020.

Dr Bhatia said: "It has been known for a long time that regional anaesthesia - i.e. a spinal epidural - is safer than general anaesthesia for caesarean sections. It has other benefits which include better pain relief; both partners being able to share in the birth experience in theatre during the procedure and earlier skin to skin contact with the baby.

"However, during the current COVID-19 pandemic, there are additional concerns that if a woman who has the virus is given a general anaesthetic, she could develop more serious respiratory problems than if she had a regional anaesthetic, and it is therefore even more important that general anaesthetics are avoided where possible. Women in labour may require a caesarean section before the team caring for them know whether she has COVID-19 or not, and therefore in these women, it is also important to avoid general anaesthesia if possible.

"General anaesthesia not only puts the woman having the caesarean section at risk of respiratory problems, but also anaesthetic staff and other healthcare workers in theatre, as tracheal intubation is an aerosol-generating procedure which poses a high risk of viral transmission from a suspected or confirmed case. It is therefore not surprising that anaesthetists were keen to avoid general anaesthesia - unless regarded as essential - in order to ensure the safest possible care for patients, and a safe working environment for staff."

In the paper, the authors also stress that general anaesthesia was still used when required in emergency situations, termed category one caesarean sections (which represent around one in six of all caesarean sections in the UK), and include situations such as fetal distress that require immediate action. In this study, the rate of general anaesthesia in the 2020 group was 12% among these category one caesarean sections, well above the overall 2020 group average of 3.7%, but also well below the rate of 25% rate for category one caesarean sections seen in the 2019 group.

Also of note was that anaesthetic staffing changed during the pandemic. On-site out-of-hours anaesthetic consultant support systems were established in 80% of the hospitals analysed. "During the first wave of the COVID-19 pandemic, most of the maternity units we studied benefitted from the presence of more experienced and skilled personnel in the delivery suite, leading to improved on-site immediate and local supervision. This possibly contributed to the high regional anaesthesia rates and lower regional to general anaesthesia conversion rates compared to the pre-COVID group," explain the authors.

They add: "Personal protective equipment (PPE) recommendations were different for women needing regional anaesthesia and at low risk of a conversion to a general anaesthesia (droplet precautions) compared with those having general anaesthesia from the commencement of caesarean section or those at high risk of conversion (airborne precautions). Donning of PPE for general anaesthesia takes time, which could theoretically result in adverse fetal outcomes in urgent/emergency caesarean sections. It is possible that this factor may have contributed to decision-making by anaesthetists."

The authors also discuss specific findings on women who tested positive for COVID-19. A total of 76 of 2480 (3%) of women tested positive in this study and the caesarean section rate for COVID-19 positive women was 36% (27 women), higher than the 29.7% reported for the 2020 group overall, but much lower than reported in other studies. Just one of these 27 women had general anaesthesia, the same proportion (3.7%) as in the 2020 group overall.

However the authors caution: "We would not want to draw any specific conclusions as we do not have the details for these women. We do not know the number of women who were swabbed for COVID-19 across hospitals regionally, and cannot therefore estimate the incidence of COVID-19 in these hospitals. We would like to highlight the fact that our dataset has one of the lowest caesarean section rates reported for COVID-19 positive pregnant women."

They conclude: "Overall, we conclude that the general anaesthesia rate for women having caesarean sections declined significantly during the peak of the COVID-19 pandemic. Anaesthetic decision-making recommendations from anaesthetic guidelines and presence of an on-site anaesthetic consultant in the delivery suite could be among the key factors that potentially influenced this decline."

"One of the important questions this study raises is: why do trainees seemingly choose general anaesthesia more frequently when they are working solo?" adds Dr Tim Meek of the Association of Anaesthetists, a consultant anaesthetist based at James Cook University Hospital, Middlesbrough, UK. "Possible explanations include lack of confidence in their regional anaesthesia skills, a perception that general anaesthesia is always quicker and, perhaps most importantly, a disproportionate focus on target decision to delivery times as the key marker of success. We should now aim to identify what enables consultants to provide regional anaesthesia confidently and focus on equipping trainees with those tools to the benefit of the women and babies we all care for."

Simply comparing the total number of deaths across countries may provide a misleading representation of the underlying level of transmission of SARS-CoV-2, the virus that causes COVID-19, because of large differences in reported COVID-19 death rates in elderly populations in different countries.

The research, conducted by scientists at the University of Cambridge and the Institut Pasteur, was published today in the leading journal Nature. It highlights how large COVID-19 outbreaks in European nursing homes, and the potential for missing deaths in some Asian and South American countries, have skewed COVID-19 death data for older age groups, rendering cross-country comparisons of the scale of the pandemic inaccurate.

The researchers say that reporting of deaths from COVID-19 among those under the age of 65 is likely to be far more reliable, and can therefore give clearer insights into the underlying transmission of the virus and enable better comparisons between countries - crucial in guiding government strategies to try to get COVID-19 under control.

"Simply comparing the total number of deaths across countries can be misleading as a representation of the underlying level of transmission of SARS-CoV-2. Most deaths are in older people, but they are the least comparable across countries," said Megan O'Driscoll, a PhD researcher in the University of Cambridge's Department of Genetics and first author of the paper.

In countries including the UK, Canada and Sweden, the COVID-19 pandemic has disproportionately affected nursing home residents, who account for over 20% of all reported COVID-19 deaths. The level of SARS-CoV-2 transmission among the general population can be difficult to disentangle from these large outbreaks.

By contrast, some countries in Asia and South America have far fewer reported COVID-19 deaths in older people than expected. One potential explanation for these 'missing deaths' is that causes of deaths in elderly populations may be less likely to be investigated and reported as countries struggle to contain the epidemic.

"Nursing homes are enclosed communities of people, and once the virus gets in it can spread quickly resulting in higher levels of infection than in the general population. We're seeing an excessively large number of deaths from COVID-19 in this older age group, particularly in countries that have many nursing homes," said Dr Henrik Salje in the University of Cambridge's Department of Genetics, the senior author of the report.

He added: "It's not just that residents are older than the general population, they are also generally more frail, so a 70-year old living in a nursing home is often more likely to die of COVID-19 than a 70-year old in the general population. To reduce the overall number of COVID-19 deaths it is vital to protect vulnerable elderly communities."

In their new model, the researchers integrated age-specific COVID-19 death data from 45 countries with 22 national-level seroprevalence surveys. Governments of many countries are using seroprevalence surveys to estimate the number of people in a population with antibodies against the coronavirus. Antibodies indicate if a person has been infected with SARS-CoV-2 at some point, so are a good indicator of population-wide infection rates.

"Our model shows that the number of COVID-19 deaths by age, in people under 65 years old, is highly consistent across countries and likely to be a reliable indicator of the number of infections in the population. This is of critical use in a context where most infections are unobserved," said O'Driscoll.

The model can be used at a country-wide level to predict a person's likelihood of dying from COVID-19 following infection, depending on their age. It also works in reverse, to estimate a country's total number of infections given its number of COVID-19 deaths in an age group, which is particularly useful in places where seroprevalence studies have not been conducted.

Using death data from under-65 age groups only, which is most representative of transmission in the whole population, it shows that by the 1 September this year an average of 5% of the population of a country had been infected with SARS-CoV-2. However, in some places it was much higher, especially South America.

For example, using Peru's COVID-19 death figures, which equate to 0.01% of the country's population, the model suggests that over half of the population of Peru has now been infected with SARS-CoV-2 - a figure far higher than expected. This indicates particularly high rates of transmission of the virus in Peru.

But even after excluding data from the over 65's, the model shows that COVID-19 death rates cannot be compared between some countries, because the relationship between infections and deaths is not consistent when other widespread 'co-morbidity' factors are involved.

"It seems that people living in places such as Slovenia and Denmark have a low probability of death following infection with SARS-CoV-2, even after accounting for the ages of their populations, which is very different to what we've seen in New York, for example. There are likely to be fundamental differences in the populations across countries, which might include their underlying health," said Salje.

The model also revealed a strong pattern across countries in the 5-9 year age group, which consistently has the lowest probability of death following SARS-CoV-2 infection.

The work demonstrates how age-specific death data alone can be used to reconstruct the underlying level of SARS-CoV-2 infection in a country and how it has changed over time. The researchers say this approach could be applied at sub-national scale, and may be of particular use in settings where large seroprevalence studies might not be feasible.