Culture

Radiation from cell phones is associated with higher rates of thyroid cancer among people with genetic variations in specific genes, a new study led by the Yale School of Public Health finds.

The researchers examined over 900 people in Connecticut and found that those with certain single nucleotide polymorphisms (genetic variations commonly referred to as SNPs and pronounced as "snips") were significantly more likely to develop cancer in their thyroid, a gland in the throat that controls metabolism.

Cell phone users with SNPs in four of the genes studied were more than two times likely to develop cancer. The researchers examined a total of 176 genes and identified 10 SNPs that appear to increase the risk of thyroid cancer among cell phone users.

Published in the journal Environmental Research, the study is believed to be the first to examine the combined influence of genetic susceptibility and cell phone use in relation to thyroid cancer.

"Our study provides evidence that genetic susceptibility influences the relationship between cell phone use and thyroid cancer," said Yawei Zhang, M.D., Ph.D., a professor in the Department of Environmental Health Sciences at the Yale School of Public Health. "More studies are needed to identify populations who are susceptible to radiofrequency radiation (RFR) and understand exposure to RFR by different using patterns of cell phones."

The findings suggest that genetic susceptibilities play an important role in cell phone use and the risk of developing thyroid cancer and could help to identify subgroups who are potentially at risk. Further research is needed to confirm the findings and to better understand the interaction between cell phone radiation and SNPs within specific genes.

The rates of thyroid cancer have been steadily increasing in the United States and in many other parts of the world, Zhang said.

According to the American Cancer Society's most recent report, there were nearly 53,000 new cases of thyroid cancer in the United States, resulting in 2,180 deaths. Thyroid cancer is three times more common in women and is diagnosed at a younger age than most other cancers.

Zhang noted that the study relied on data collected from 2010 to 2011 when smartphones were first being introduced to the market. At the time, only a small proportion of people had smart phones. Therefore, if cell phone use increased the risk of thyroid cancer, it was possibly due to the use of earlier generation cell phones that were more commonly used when the data was collected.

Additionally, the transition to smartphones has also seen a major change in how cell phones are used (e.g., texting vs. phone calls). As a result, findings from this current study warrant a further evaluation in future studies, she said.

RESEARCH TRIANGLE PARK, N.C. -- Researchers working on an Army project developed nanoscale thermal switches that are key to thermal management of nanoscale devices, refrigeration, data storage, thermal computing and heat management of buildings.

The journal Nature Nanotechnology published an Army-funded study from University of Michigan researchers that showed for the first time how a nanoscale thermal switch can be built by employing nanoscale effects that arise when heat is transferred between a hot and cold nanoscale-thick membrane via thermal radiation.

In comparison to the vast array of devices, such as transistors and diodes that are available to control the flow of electricity, there exists currently very few proposals for controlling the flow of heat, especially at the nanoscale. To overcome this challenge researchers have been exploring nanoscale phenomena that may enable novel functional thermal devices.

"It's exciting to see Army investments in basic research leading to the discovery of new effects and proof of concept demonstrations of novel thermal devices," said Dr. Chakrapani Varanasi, a program manager at the Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "These findings can have a strong impact on thermal management for next generation computing for the military."

The Army's network modernization strategy is designed to enable the Army to fight tonight while also actively seeking next-generation solutions to stay ahead of potential adversaries.

A 2018 discovery by the research team, which highlighted how heat is transported in preferential directions from nanoscale membranes, led Dr. Dakotah Thompson, the lead author of the 2018 study, to begin exploring potential applications.

"After some thought it became apparent to us that we could potentially create a thermal switch by controlling the emission properties of the nanomembranes by bringing a third object into close proximity of the nanomembrane," said Dr. Edgar Meyhofer, a professor of mechanical engineering at the University of Michigan.

In order to test this hypothesis, Thompson developed a scheme where a planar object can be brought into close proximity (microns) of two co-planar membranes that were exchanging heat.

"In order to accomplish this challenging goal, I nanofabricated both suspended calorimetric devices that had unprecedented calorimetric resolution and a planar mesa-shaped object, and controlled the separation between them using a custom developed nanopositioner," Thompson said.

From these experiments the authors could show that heat transfer between nanoscale membranes can be turned on and off by simply modifying the separation between the membranes and the planar mesa.

In order to make precise numerical predictions of the experimental observations, Dr. Linxiao Zhu, a post-doctoral fellow at Michigan, and Thompson performed detailed calculations that showed how the observations can be quantitatively related to how the propagation of light, which is the carrier of heat, from one membrane to the other is impeded by the planar mesa which can either absorb the light propagating between the membranes or reflect it away from the membranes.

Scientists at the CCDC Army Research Laboratory are closely following this research to use these developments to create novel Army relevant devices.

One of the most controversial hypotheses for the origin of human language faculty is the evolutionary conjecture that language arose instantaneously in humans through a single gene mutation. `

Two recent publications by researchers at the University of Barcelona (UB), led by Cedric Boeckx, ICREA Research professor from the Section of General Linguistics and member of the Institute of Complex Systems of the UB (UBICS), question this hypothesis, advocated among others by linguist Noam Chomsky, and suggest that it is more likely that language evolved gradually.

Merge, the cognitive operation key to human language

For decades, several scholars such as Chomsky have proposed that modern humans are genetically equipped with a unique cognitive capacity that specifically allows us to implement computations over hierarchically structured symbolic representations. This capacity is enabled by a formally simple cognitive operation known as Merge, which is the basis of our ability to represent complex grammars in a way that other species cannot. "Merge is claimed to be sufficient to yield grammatical structure. Put it simple, Merge takes two linguistic units (say, words) and combines them into a set that can then be combined further with other linguistic units, effectively creating unbounded linguistic expressions. These, in turn, are claimed to form the basis for our cognitive creativity and flexibility, setting us aside from other species," said Cedric Boeckx.

"The strongest version of this hypothesis --Cedric Boeckx continued -- suggests that the biological foundation of our modern language capacity is a single genetic mutation, a macromutation, that emerged instantaneously in a single hominin individual who is an ancestor of all modern humans, and spread through the population."

Modeling the single gene mutation hypothesis

In the first paper, published in Scientific Reports -with participation of Cedric Boeckx and researchers from the Free University of Brussels (Belgium) and the Max Plank Institute of Psycholinguistics (Netherlands), they examine this hypothesis by modeling the evolutionary dynamics of such a scenario, taking into account different parameters such as how long ago this mutation would have happened and the population size at the time. "We examine the dynamics of a single, critical, mutation spreading rapidly through a population in a given time window, combining this theoretical proposal with contemporary genetic and demographic findings", said Cedric Boeckx.

In this case, researchers have applied a variety of techniques from theoretical biology to the question of how to quantify the probability of a complex trait like language evolving in a single step, in many small steps, or in a limited number of intermediate steps, within a specific time window and population size.

Researchers concluded that, instead of a single mutation with an extremely large fitness advantage, the most likely scenario is one where higher number of mutations, each with moderate fitness advantages, accumulate. "A scenario in which the genetic bases of our linguistic ability evolved through a gradual accumulation of smaller biological changes. This scenario can be articulated in many different ways, for instance as syntax evolving from phonological form, from rapid manual actions or from much simple pragmatic sequencing of words", said Boeckx.

Challenging the logic of the hypothesis

In the other study, published in PLoS Biology, UB graduate student Pedro Tiago Martins and Cedric Boeckx question this evolutionary hypothesis from a different angle: by going over its logic. Defendants of the single hypothesis claim that Merge, being such a simple operation had to be the result of a single genetic mutation that endowed one individual with the necessary biological equipment for language. In addition, because Merge is either fully present or fully absent --in other words, there cannot be such a thing as half-Merge--, the human language faculty had to emerge suddenly, as the result of this single mutation.

"From the formal properties of Merge, it is not possible to derive of number of evolutionary steps that led to the emergence of Merge. The computational simplicity of Merge does not correlate in any meaningful way to biological simplicity, and that once different levels of organization are taken into account there is no way to derive such simplistic evolutionary scenarios for any complex trait.",said Pedro Tiago Martins. The study highlights that even if a trait, such as the Merge operation, does not manifest itself in intermediate steps, its evolution may very well be gradual.

Researchers explained that the evolution of something as complex as human language deserves integration of results and insights from different corners of the research landscape, namely the fields of neurobiology, genetics, cognitive science, comparative biology, archaeology, psychology, and linguistics. "This is hard because it requires compatible levels of granularity between all fields involved, but it is the only way of achieving meaningful understanding," said Pedro Tiago Martins.

Together, these studies suggest that evolutionary reasoning does not warrant a scenario of sudden emergence of human language by means of a single mutation, and that it is more likely instead that language evolved gradually.

In a new short paper in the journal Nature Machine Intelligence, Roger A. Søraa from Norwegian University of Science and Technology (NTNU) and co-authors Eduard Fosch-Villaronga from Leiden University in the Netherlands, and Adam Poulsen from Charles Sturt University in Australia discuss what a queering of robots might entail.

"It is imperative that we construct mechanisms and policies that acknowledge the importance of inclusivity, diversity, and non-discrimination, also for the LGBTQ+ community in the development and use of robots and AI," the researchers wrote.

They point out that technology is not developed in a vacuum, but instead reflects biases and reproduces societal values and beliefs.

Søraa is active in robot and cyborg research through the newly started Immersive Technology and Social Robots Lab at NTNU, and has been active in queer and gender debates, including starting the NTNU LGBTQ+ networks for employees.

Søraa and his co-authors highlight the lack in the inclusion of queer perspectives on robots and machines. This, they argue, should be better recognized in both the research and design of the robots of the future, and should prod developers and designers to be more inclusive in how they build and create the machines that increasingly walk, talk and act among us.

Scientists and engineers from Nanyang Technological University, Singapore (NTU Singapore) and the University of Leeds in the UK have created the first electrically-driven 'topological' laser, which has the ability to route light particles around corners - and to cope with defects in the manufacture of the device.

Electrically-driven semiconductor lasers are the most common type of laser device today. They are used in products such as barcode readers and laser printers, for fibre optic communications, and in emerging applications such as laser ranging sensors for self-driving cars.

However, their manufacture is an exacting process and current laser designs do not work well if any defects are introduced into the structure of the laser during these processes.

The Singapore-UK advance reported in Nature today (12 February) overcomes this long-standing problem and promises to lead to more efficient and less wasteful manufacturing using existing semiconductor technologies. This is accomplished by harnessing a concept from theoretical physics known as the topological states, in order to make a 'topological laser'.

In the 1980s scientists found that electrons flowing in certain materials have 'topological features' - meaning that they can flow around corners or imperfections without scattering or leaking. The 2016 Nobel Prize in Physics was awarded to three theoretical physicists who pioneered the study of such topological states of electrons.

Now, an interdisciplinary team of engineers and physicists from NTU Singapore in collaboration with material scientists from the University of Leeds, have applied this topological approach to light particles, known as photons.

"Every batch of manufactured laser devices has some fraction that fails to emit laser light due to imperfections introduced during fabrication and packaging," said Professor Qi Jie Wang, the lead scientist from NTU Singapore's School of Electrical and Electronic Engineering. "This was one of our motivations for exploring topological states of light, which are much more robust than ordinary light waves."

In the present study, the researchers worked with a type of electrically-driven laser called a quantum cascade laser, based on advanced semiconductor wafers developed at the University of Leeds.

A senior author of the study, Professor Giles Davies FREng, Pro-Dean for Research and Innovation in the Faculty of Engineering and Physical Sciences at the University of Leeds, said: "The topological laser is a great example of a fascinating fundamental scientific phenomenon being applied to a practical electronic device, and as our study shows, it has the potential to improve the performance of laser systems."

To achieve topological states on a laser platform, the NTU and Leeds team developed a new design containing a valley photonic crystal, which was inspired by electronic topological materials known as two-dimensional valleytronic insulators.

The design consists of hexagonal holes arranged in a triangular lattice, etched into a semiconductor wafer, making it extremely compact.

Within the microstructure, the topological states of light circulate within a triangular loop of 1.2 millimetre circumference, acting as an optical resonator to accumulate the light energy required to form a laser beam.

"The fact that light circulates in this loop, including going around the sharp corners of the triangle, is due to the special features of topological states," says Associate Professor Yi Dong Chong, a theoretical physicist in NTU Singapore's School of Physical and Mathematical Sciences and co-lead investigator of the project. "Ordinary light waves would be disrupted by the sharp corners, preventing them from circulating smoothly."

The researchers note that an interesting feature of the new topological quantum cascade laser is that the light it emits is at terahertz frequencies between the microwave and infrared regions of the electromagnetic spectrum. Terahertz light has been identified as one of the principal realms from which future technological applications in sensing, illumination, and wireless communications may emerge.

This research project spanned two years, and involved an interdisciplinary team of twelve researchers. Team members also include NTU physicists: Associate Professor Baile Zhang, postdoctoral research fellow and first author of the paper, Dr Yongquan Zeng; as well as Professor Edmund Linfield, Professor of Terahertz Electronics, and Dr Lianhe Li, Senior Research Fellow, both at Leeds.

Looking ahead, the joint team is working on lasers that make use of other types of topological states.

"The design we used in this project, called a valley photonic crystal, is not the only way to create topological states," Professor Wang said. "There are many different types of topological states, imparting protection against different kinds of imperfections. We think it will be possible to tailor the design to the needs of different devices and applications."

In 2018, a team at the Technion - Israel Institute of Technology and the University of Central Florida in the USA developed a topological laser made from an array of connected optical resonators. The researchers showed that the topological states of light could travel efficiently around corners and defects in the laser array. However, this prototype laser had the drawback of being much larger than most semiconductor lasers, as well as being 'optically driven', meaning that it was powered by another laser.

In Brazil there is a plant so strange that researchers predicted - and 27 years later, proved - that opossums are key to its pollination. The findings are published in the Ecological Society of America's journal Ecology.

The plant Scybalium fungiforme, a little-known fungus-like species of the family Balanophoraceae, has bunches of tiny pale flowers that are surrounded and housed by a hard surface of bracts - like on an artichoke. Because of their scale-like shape, the bracts must be opened or peeled back to expose the flowers and nectar to pollinators such as bees.

While most species in the Balanophoraceae plant family are primarily pollinated by bees and wasps, researchers at São Paulo State University in Botucatu, Brazil hypothesized something different. They thought that opossums, with their opposable thumbs, would be a key pollinator for S. fungiforme due to the challenging bracts covering the flowers.

In the early 1990s Patrícia Morellato, a professor at the university, first made the prediction. She and her colleagues studied the plant and they captured an opossum with nectar on its nose. There observations went unpublished because they did not record or obtain direct evidence of the opossums pollinating the flowers.

Felipe Amorim, assistant professor at the university and lead author on this study, did not encounter the plant until 2017, but hypothesized that a non-flying mammal is needed for pollination based on the flower morphology. In April 2019 his students independently hypothesized that perhaps rodents could act as the main pollinators of this species. "At that time, neither of us knew anything about the unpublished observations made by Patrícia in the '90s,'" he explains.

In May 2019 Amorim and a team of researchers went to Serra do Japi Biological Reserve, located about 50 km from the area studied by Morellato, and set up night-vision cameras to record the activity of nocturnal flower visitors. The cameras captured opossums removing bracts from the fungus-like plant and pushing their faces into the flowers to eat the nectar. It was the first direct evidence of opossums pollinating the plant.

Amorim sent his colleague Morellato the footage. "When she watched the videos," he says, "she sent me a voice message as excited as we were when we first saw the opossum visiting the flowers, because it was the first time she saw something she predicted two and a half-decades ago!"

The researchers had made the opossum prediction based on "pollination syndrome" - the concept that floral attributes such as color, morphology, scent, and size reflect the adaptation of a plant species to pollination by a certain group of animals. Opossums, having "hands" with opposable thumbs, are capable of peeling back the scale-like leafs covering the flowers of S. fungiforme. The plant does have other floral visitors that act as secondary pollinators once the bracts are removed - bees and wasps dominate the crowd, but a surprising additional visitor was several hummingbirds.

"Based on the flower morphology," Amorim says, "Morellato, my students, and I could safely predict that this plant should be pollinated by non-flying mammals, but the occurrence of hummingbirds coming to the ground to visit these flowers was something completely unexpected to me." Morellato had not seen any hummingbirds visiting this species at her study site during the '90s, but researchers have more recently obtained indirect evidence that hummingbirds visit the plant in both study locations.

The authors hope to continue studying the pollinators of S. fungiforme to assess the efficiency of each group of flower visitor (mammals, hummingbirds, and bees and wasps) in order to quantify their contribution to the fruit production of this plant. They also want to analyze the chemical compounds of nectar and floral scent, which can reveal much about the adaptation of a plant for a given group of pollinator.

Overall, the story is an interesting one to tell, the culmination of nearly three decades of prediction and observation based on the hard shell surrounding a bunch of tiny flowers. Amorim contemplates that "at the time that non-flying mammals were first predicted as the pollinators of this fungus-like plant, I was about 11 years old, and most of the authors of this study haven't even had born!"

Brain-eating amoebae can cause particularly harmful forms of encephalitis, and more than 95% of people who develop these rare but devastating infections die. Despite the high mortality rate, there is currently no single effective drug available to fight these microbes. Now, however, researchers have designed some new compounds that show promise in the laboratory as treatments, according to a report in ACS Chemical Neuroscience.

Naegleria fowleri and Balamuthia mandrillaris are two types of amoebae that can cause primary amoebic meningoencephalitis and granulomatous amoebic encephalitis. They are single-celled microorganisms that live in water and soil, and can enter the body through the nose or open wounds. These pathogens can then move to the central nervous system, where they destroy brain cells. In the very few cases that have been treated successfully, patients were given high doses of many different antimicrobials. However, these drugs generally lack specificity and can have toxic effects at high levels. To make progress toward a single drug, Ruqaiyyah Siddiqui and colleagues turned to quinazolinones. These compounds are effective against a wide spectrum of human foes, including bacteria, viruses, fungi, parasites and cancer, but they had never been tested against brain-eating amoebae.

The researchers synthesized 34 new quinazolinone derivatives and studied their effects on N. fowleri and B. mandrillaris. Some of the new compounds were effective at killing the microorganisms and limiting the harm the pathogens could do to human cells in a Petri dish. In some cases, attaching silver nanoparticles to the derivatives enhanced that activity. The most effective compounds contained chlorine, methyl or methoxy groups, and their toxicity for human cells was low. The researchers say their results show that quinazolinones are good candidates for drug development studies.

As a result of climate change, more frequent and longer drought periods are predicted in the future. Drought risks are suggested to decrease agricultural yield. Researchers at the University of Bayreuth and the Leibniz Centre for Agricultural Landscape Research (ZALF) have now discovered a way to mitigate this problem: Amorphous silica is able to significantly increase the amount of available water for plants. This offers an opportunity to enhance global food security despite climate change. The researchers presented their findings in the journal Scientific Reports. They suggest a soil management that ensures a higher amorphous silica content.

The new research results are the product of close collaboration between environmental geochemists and soil physicists. The scientists have systematically investigated how amorphous silica affects the ability of soils to absorb and store water, for the first time. The results are impressive: Even if the proportion of amorphous silica in soils increases by just one percent by weight, the amount of plant available water in soils increases by up to 40 percent - or even more", reports Dr. Jörg Schaller from the Department of Environmental Geochemistry at the University of Bayreuth and ZALF. This is because gels, which contain enormous amounts of water, form in the soil out of amorphous silica molecules. These water supplies are easily accessible to the roots of plants.

However, it has been known for some time that conventional methods of agriculture lead to a steady decline of the content of amorphous silica in the soil. In combination with the expected consequences of climate change, this may lead to serve drought problems in e.g. agricultural systems in future, decreasing yield even more. This increases the risks to global food security. "Our new study shows a way to mitigate this risk. For this, soil management should be modified to increase the amorphous silica stocks in soils. Moreover, artificial produce amorphous silica - which has the same chemical properties as the biogenic silica - should be used as soil amendments. Such soil silica amendments may play an important role in global food security in the future," Schaller said.

St. Paul, MN (February 2020)--Transmitted by insects, especially the aster leafhopper, aster yellows (AY) outbreaks can cause severe production losses in many crops, including carrots, lettuce, and canola. Canola is a billion-dollar crop for Canada but the growing season in Western Canada is very short. Depending on the environmental conditions and number of infected leafhoppers, AY can be transmitted to canola in less than 24 hours and the leafhoppers can continue spreading the disease for the rest of their lives.

Scientists based in Saskatoon, Canada, developed a rapid, simple laboratory and field-adaptable DNA extraction method that allowed them to identify both plant pathogen and insect vector using molecular barcoding and gene sequencing. This method reduced the time from collection of insects to a positive identification of the presence of a pathogen from up to two weeks to less than one hour. They published their findings in Plant Health Progress.

"Using this methodology, we were able to go from DNA extraction to pathogen detection in less than one hour," according to lead author Karolina Pusz-Bochenska. "This rapid technique allows for same-day management decisions essential to preventing the spread of insect-transmitted pathogens."

To achieve this quick turnaround, Pusz-Bochenska and colleagues used DNA lysis paper to extract pathogen DNA, which was a novel choice that they combined with the rapid-detection potential of the sensitive and field-adaptable loop-mediated isothermal amplification (LAMP) assay. According to Pusz-Bochenska, this combination was groundbreaking.

"When the aster leafhoppers migrate into Canada in spring, they bring AY phytoplasmas that can cause devastating damage to canola crops, and we need a rapid-test to determine if these migrant leafhoppers are a threat or not. A rapid analysis of the leafhoppers allows us to estimate the infectivity of the population and forecast the risk to the crops, allowing the growers to make management decisions if the leafhoppers have arrived in their fields."

While this research focuses on agriculture, this techniques has potential applications to horticulture as well as animal and human health. For more details, read "A Rapid, Simple, Laboratory and Field-Adaptable DNA Extraction and Diagnostic Method Suitable for Insect-Transmitted Plant Pathogen and Insect Identification," which is freely available through the end of March.

New research spearheaded by McGill University has discovered that bacteriophages (viruses that infect bacteria) found in the intestinal tracts of children may play a role in childhood stunting, a significant impediment to growth that affects 22% of children under the age of five around the world.

The study, published today in Cell Host & Microbe, also suggests that because they affect the abundance and diversity of bacterial communities in the gastrointestinal tract, these viruses could also be used to improve health. The researchers believe this work offers hope of developing new cost efficient therapies for populations where nutritional interventions, which have been shown to work, are difficult to implement and sustain in vulnerable human populations.

Phages, bacteria and stunting

Earlier studies had suggested that the gut microbiome might play a role in stunting by showing that stunted children have increased numbers of disease-causing bacteria--associated with impaired digestive and absorption functions--living in their gastrointestinal tracts.

But while much research has focused on the bacteria present in our gut and the influence they can have on human health, little attention has thus far been paid to other very common residents of our gastrointestinal tract - bacteriophages.

"Phages or bacteriophages, which are bacterial viruses, are naturally found in every environment where bacteria are found, and the human gut is no exception," says Corinne Maurice, an assistant professor in McGill's Department of Microbiology and Immunology and senior author of the new study. "Because phages are as abundant as their hosts, they might be involved in regulating them in many ways by killing specific bacteria, transferring virulence or antibiotic resistance genes to them, for example, but we currently don't have a clear understanding of what they do and how they do it. This is a fairly new and exciting field of research."

Distinct viruses in healthy and stunted children

To understand how these viruses might play a role in stunting, Maurice's team, in collaboration with the International Centre for Diarrheal Disease Research in Bangladesh, collected fecal samples from 30 non-stunted and 30 unrelated stunted Bangladeshi children aged between 14 and 38 months.

Using a combination of microscopy, ribosomal gene sequencing, and metagenomics, they were able to determine that the phages found in the gut of non-stunted and stunted children are distinct. Furthermore, when gut bacteria from non-stunted children were exposed to phages from the guts of stunted children in vitro, they found that "bad" bacteria, suspected of being involved in stunting, proliferated.

"By showing that phages can change the bacterial community in children between 6 and 23 months, our work shows the potential of phages for reestablishing the gut bacterial community in stunting," says Mohammadali Khan Mirzaei, a former postdoctoral student in the Maurice lab and first author of the new study.

"Stunting has lifelong consequences (health/socioeconomic) and can be transferred from mother to child," says Maurice, who is also Canada Research Chair in Gut Microbial Physiology and a CIFAR Azrieli Global Scholar. "If phages can change bacterial communities in a specific way and long-term during child development, this could be a cheap treatment with no risk of antibiotic resistance."

Though the findings now need to be validated using a larger sample and in animal models, Maurice says that by understanding interactions between bacteria and viruses in the human gut, we might be able to one day manipulate them to improve human health.

In many industrial processes, such as in bioreactors that produce fuels or pharmaceuticals, foam can get in the way. Frothy bubbles can take up a lot of space, limiting the volume available for making the product and sometimes gumming up pipes and valves or damaging living cells. Companies spend an estimated $3 billion a year on chemical additives called defoamers, but these can affect the purity of the product and may require extra processing steps for their removal.

Now, researchers at MIT have come up with a simple, inexpensive, and completely passive system for reducing or eliminating the foam buildup, using bubble-attracting sheets of specially textured mesh that make bubbles collapse as fast as they form. The new process is described in the journal Advanced Materials Interfaces, in a paper by recent graduate Leonid Rapoport PhD '18, visiting student Theo Emmerich, and professor of mechanical engineering Kripa Varanasi.

The new system uses surfaces the researchers call "aerophilic," which attract and shed bubbles of air or gas in much the same way that hydrophilic (water-attracting) surfaces cause droplets of water to cling to a surface, spread out, and fall away, Varanasi explains.

"Foams are everywhere" in industrial processes, he says, including beer brewing, paper making, oil and gas production and processing, biofuel generation, shampoo and cosmetics production, and chemical processing.

Also, "It's one of the main challenges in cell culture or in bioreactors," he adds. To promote cell growth, various gases are typically diffused through the water or other liquid medium. But this can lead to a buildup of foam, and as the tiny bubbles burst they can produce shear forces that can damage or kill the cells, so controlling the foam is essential.

The usual way of dealing with the foam problem is by adding chemicals such as glycols or alcohols, which typically then need to be filtered out again. But that adds cost and extra processing steps, and can affect the chemistry of the product. So, the team asked, "How can you get rid of foams without having to add chemicals? That was our challenge," Varanasi says.

To tackle the problem, they created high-speed video in order to study how bubbles react when they strike a surface. They found that the bubbles tend to bounce away like a rubber ball, bouncing several times before eventually sticking in place, just as droplets of liquid do when they hit a surface, only upside down. (The bubbles are rising, so they bounce downward.)

"In order to effectively capture the impacting bubble, we had to understand how the liquid film separating it from the surface drains," says Rapoport. "And we had to start at square one because there wasn't even an established metric to measure how good a surface is at capturing impacting bubbles. Ultimately, we were able to understand the physics behind what causes a bubble to bounce away, and that understanding drove the design process."

The team came up with a flat device that has a set of carefully designed surface textures at a variety of size scales. The surface was tuned so that bubbles would adhere right away without bouncing, and quickly spread out and dissipate to make way for the next bubble instead of accumulating as foam.

"The key to quickly capturing bubbles and controlling foam turned out to be a three-layered system with features of progressively finer sizes," says Emmerich. These features help to trap a very thin layer of air along the surface of a material. This surface, known as a plastron, has similarities to the texture of some feathers on diving birds that help keep the animals dry underwater. In this case, the plastron helps to make the bubbles stick to the surface and dissipate.

The net effect is to reduce the time it takes for a bubble to stick to the surface by a hundredfold, Varanasi says. In tests, the bouncing time was reduced from hundreds of milliseconds to just a few milliseconds.

To test the idea in the lab, the team built a device containing a bubble-capturing surface and inserted it into a beaker that had bubbles rising through it. They placed that beaker next to an identical one containing foaming suds with a sheet of the same size, but without the textured material. In the beaker with the bubble-capturing surface, the foam quickly dissipated down to almost nothing, while a full layer of foam stayed in place in the other beaker.

Such bubble-capturing surfaces could easily be retrofitted to many industrial processing facilities that currently rely on defoaming chemicals, Varanasi says. He speculated that in the longer run, such a method might even be used as a way to capture methane seeping from melting permafrost as the world warms. This could both prevent some of that potent greenhouse gas from making it into the atmosphere, and at the same time provide a source of fuel. At this point that possibility is "pie in the sky," he says, but in principle it could work.

Unlike many new technology developments, this system is simple enough that it could be readily implemented, Varanasi says. "It's ready to go. ... We look forward to working with industry."

The work was supported by the Bill and Melinda Gates Foundation.

Dr Katerina Johnson, who conducted her PhD in the University's Department of Experimental Psychology, was researching the science of that 'gut feeling' - the relationship between the bacteria living in the gut (the gut microbiome) and behavioural traits. In a large human study she found that both gut microbiome composition and diversity were related to differences in personality, including sociability and neuroticism.

She said: "There has been growing research linking the gut microbiome to the brain and behaviour, known as the microbiome-gut-brain axis. Most research has been conducted in animals, whilst studies in humans have focused on the role of the gut microbiome in neuropsychiatric conditions. In contrast, my key interest was to look in the general population to see how variation in the types of bacteria living in the gut may be related to personality."

Previous studies have linked the gut microbiome to autism (a condition characterised by impaired social behaviour). Dr Johnson's study found that numerous types of bacteria that had been associated with autism in previous research were also related to differences in sociability in the general population. Katerina explained: "This suggests that the gut microbiome may contribute not only to the extreme behavioural traits seen in autism but also to variation in social behaviour in the general population. However, since this is a cross-sectional study, future research may benefit from directly investigating the potential effect these bacteria may have on behaviour, which may help inform the development of new therapies for autism and depression."

Another interesting finding related to social behaviour was that people with larger social networks tended to have a more diverse gut microbiome, which is often associated with better gut health and general health. Katerina commented: "This is the first study to find a link between sociability and microbiome diversity in humans and follows on from similar findings in primates which have shown that social interactions can promote gut microbiome diversity. This result suggests the same may also be true in human populations." Conversely, the study found that people with higher stress or anxiety had a lower microbiome diversity.

Various other key and novel findings were also reported in this study. Most notably, adults who had been formula-fed as children had a less diverse microbiome in adulthood. Katerina commented: "This is the first time this has been investigated in adults and the results suggest that infant nutrition may have long-term consequences for gut health." Diversity was also positively related to international travel, perhaps due to exposure to novel microbes and different diets. More adventurous eaters had a more diverse gut microbiome whilst those on a dairy-free diet had lower diversity. Furthermore, diversity was greater in people with a diet high in natural sources of probiotics (e.g. fermented cheese, sauerkraut, kimchi) and prebiotics (e.g. banana, legumes, whole grains, asparagus, onion, leek), but notably not when taken in supplement form.

"Our modern-day living may provide a perfect storm for dysbiosis of the gut. We lead stressful lives with fewer social interactions and less time spent with nature, our diets are typically deficient in fibre, we inhabit oversanitized environments and are dependent on antibiotic treatments. All these factors can influence the gut microbiome and so may be affecting our behaviour and psychological well-being in currently unknown ways."

COLUMBUS, Ohio - A new study uses China's one-child policy to show that having fewer children leads women to achieve higher levels of education.

The research found that the one-child policy alone accounted for about half of the additional education that women in China achieved after the policy was put in place.

"The findings suggest that some Chinese women anticipated having fewer children due to the one-child policy and they postponed marriage and postponed having children while they increased their education," said Xuan Jiang, a postdoctoral researcher in economics at The Ohio State University.

Jiang's study was published recently in the journal Contemporary Economic Policy.

Population data collected by the Chinese government since 2010 made it possible for Jiang to analyze how fertility decisions affect education in women. There has been no other way to study the issue in this way before, she said.

As such, she emphasized that the study is not defending the one-child policy, which critics say led to human rights abuses. Moreover, the results may have broader implications beyond China for explaining the link between motherhood and education.

"Economists have wanted to know why the education gap between men and women has closed in many countries. This study shows that reductions in fertility may play an important role," she said.

Jiang used data from the ongoing Chinese Family Panel Studies, a nationally representative annual longitudinal survey conducted by Peking University and funded by the Chinese government.

China's one-child policy was instituted in 1979 to control the country's rapidly growing population. But it didn't apply equally to all groups. This study focused on the Han, the ethnic majority in China who were most strictly controlled by the law.

Jiang compared two groups: an older generation (born 1950-1959) whose education decisions would not have been affected by the one-child policy and a younger generation (born 1960-1980) whose decisions would be impacted.

Overall, while men born in 1950 had significantly more education than women born that year, men and women born in 1980 had about equal levels - nearly nine years of schooling.

Jiang first compared Han women versus Han men from older and younger generations.

The results showed that, after taking into account other factors that could have affected educational attainment, the one-child policy was responsible for increasing Han women's years of schooling by 1.28 years compared to Han men. That explains 53 percent of the 2.38-year increase in education attainment of women born between 1950 and 1980.

"Being able to explain more than half of educational attainment with one factor - the one-child policy - is enormous," Jiang said. "That is very surprising for economists."

She noted that in a broader context, women in countries worldwide experienced increases in education in the same time frame. Could there be other worldwide social forces at work that affected women in China?

To control for that possibility, Jiang conducted a second analysis that compared Han women to non-Han women in China who were not subject to the strict one-child policy.

The results were nearly identical to the first analysis: The Han women's educational attainment increased by 1.29 years compared to non-Han women.

Jiang did another test, looking specifically at young women who had one or more parents who were members of the ruling Communist party.

"The Communist Party implemented the one-child policy and there were punishments for party members whose families did not follow the birth quota," Jiang said.

"So you would expect that the one-child policy would have an even stronger effect for young women whose parents were members."

And that is indeed what she found: The one-child policy had a more robust impact on increasing education among children of Communist Party members.

Jiang also analyzed what happened to women after their schooling was over.

Results showed that the one-child policy delayed women's first marriages, delayed how soon they had a child and increased how many entered the job market.

"Women anticipated having fewer children, which may have delayed their entry into parenthood and even delayed the decision to get married, which allowed them to get more education," Jiang said.

"And with the further education, they were more likely to get jobs."

The results show the powerful influence that the one-child policy had on Chinese society, she said.

"The one-child policy fundamentally changed the lives and family structure of the generations born in the 1960s and later."

DALLAS, Feb. 12, 2020 -- Researchers have developed a simple risk score prediction model to help determine stroke risk in adults who experience migraine accompanied by aura, according to preliminary research to be presented at the American Stroke Association's International Stroke Conference 2020 - Feb. 19-21 in Los Angeles, a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

Some people with migraines experience neurological symptoms affecting vision (visual aura) such as flashes of light and blind spots or tingling in the hands or face. In adults, symptoms usually happen before the headache itself, and younger women are at higher risk for migraine with aura.

"People who have migraine with aura are at increased risk for an ischemic stroke," said Souvik Sen, M.D., M.P.H., study co-author, and professor and chair of the neurology department at the University of South Carolina School of Medicine in Columbia, South Carolina. "With our new risk-prediction tool, we could start identifying those at higher risk, treat their risk factors and lower their risk of stroke."

Researchers reviewed data from the Atherosclerosis Risk in Communities Cohort (ARIC), a community-based group of people from four U.S. localities (Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburbs of Minneapolis, Minnesota) who have been followed since 1987. They evaluated the data of 429 adults (mostly women) with a history of migraine with aura who were in their 50s at the first visit. By the end of the study, participants were in their 70s.

They identified five risk factors for stroke and created a prediction model with each factor assigned a number of points proportional to its influence: diabetes (7 points), age greater than 65 years (5 points), heart rate variability (3 points), high blood pressure (3 points) and gender (1 point). Because the study group contained few men and migraines primarily affect women, fewer points were added for females. After calculating scores for each person, researchers classified participants into one of three groups: low-risk (0 to 4 points), intermediate-risk (5 to 10 points) and high-risk (11 to 21 points).

Researchers found:

Over an average of 18 years of follow-up, 32 people experienced a stroke.

At the end of 18 years, 3% in the low-risk group had a stroke, 8% in the intermediate-risk group had a stroke, and 34% in the high-risk group had a stroke.

Compared to the low-risk group, migraine with aura sufferers in the high-risk group were about 7 times more likely to have a stroke.

According to the researchers, the new risk-prediction tool needs to be validated in a larger population prior to being used in a clinical setting.

DALLAS, Feb. 12, 2020 -- A portable, low-field Magnetic Resonance Imaging (MRI) system may become a safe and practical way to get accurate brain images at a patient's bedside, according to preliminary research to be presented at the American Stroke Association's International Stroke Conference 2020 - Feb. 19-21 in Los Angeles, a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

"We've flipped the concept from having to get patients to the MRI to bringing the MRI to the patients," said Kevin Sheth, M.D., senior author and chief physician, Division of Neurocritical Care and Emergency Neurology at Yale School of Medicine and Yale New Haven Hospital in Connecticut. "This early work suggests our approach is safe and viable in a complex clinical care environment."

Eighty-five stroke patients (46% women, age 18-96, 46% ischemic stroke, 34% intracerebral hemorrhage, 20% subarachnoid hemorrhage) received bedside, low-field MRI within seven days of symptom onset. The exam time averaged about 30 minutes, and most patients were able to complete the entire exam. However, five patients could not fit into the 30-centimeter opening of the MRI machine, and six patients experienced claustrophobia, factors which halted their test.

"We started this research several years ago because obtaining accessible, meaningful brain imaging for patients has been a major worldwide health care gap for decades," Sheth said. "The whole thing works because we are using low-field magnets to acquire brain images after a stroke."

Currently, patients must travel to the location of a high-field MRI device. However, advances in low-field MRI have enabled acquisition of clinically useful images using a portable device at bedside.

"High-field magnets are the cornerstone of commercial MRIs. The portable, low-field MRI could be used at hospitals that currently have a high-field MRI and in any other setting where an MRI is currently not available."

He added that the portable MRI devices will also decrease need for a special power supply, cooling requirements, cost and other barriers that currently limit easy patient access

In addition, the low-field, bedside MRI scanner did not interfere with other equipment, and metals did not need to be removed from the room. No significant adverse events were reported.

"There's a lot of work to do, however, we've cracked the door open for bringing this technology to any setting, anywhere. In rural settings, urban advanced hospitals and in remote villages in areas of the world where it's hard to get an MRI - not anymore," Sheth said.

Sheth said next steps include scanning more patients, improving image quality, using the devices in multiple settings and using machine learning to extract as much meaningful information as possible.