Tech

Irvine, CA - July 27, 2020 - In a new study, researchers found that night- versus day-biting species of mosquitoes are behaviorally attracted and repelled by different colors of light at different times of day. Mosquitoes are among major disease vectors impacting humans and animals around the world and the findings have important implications for using light to control them.

The University of California, Irvine School of Medicine-led team studied mosquito species that bite in the daytime (Aedes aegypti, aka the Yellow Fever mosquito) and those that bite at night (Anopheles coluzzi, a member of the Anopheles gambiae family, the major vector for malaria). They found distinct responses to ultraviolet light and other colors of light between the two species. Researchers also found light preference is dependent on the mosquito's sex and species, the time of day and the color of the light.

"Conventional wisdom has been that insects are non-specifically attracted to ultraviolet light, hence the widespread use of ultraviolet light "bug zappers" for insect control. We find that day-biting mosquitoes are attracted to a wide range of light spectra during the daytime, whereas night-biting mosquitoes are strongly photophobic to short-wavelength light during the daytime," said principal investigator Todd C. Holmes, PhD, a professor in the Department of Physiology and Biophysics at the UCI School of Medicine. "Our results show that timing and light spectra are critical for species-specific light control of harmful mosquitoes."

The new study titled, "Circadian Regulation of Light-Evoked Attraction and Avoidance Behaviors in Daytime- versus Nighttime-Biting Mosquitoes," is published in Current Biology. Lisa S. Baik, a UCI School of Medicine graduate student researcher who recently completed her PhD work, is first author.

Mosquitoes pose widespread threats to humans and other animals as disease vectors. It is estimated historically that diseases spread by mosquitoes have contributed to the deaths of half of all humans ever to have lived. The new work shows that day-biting mosquitoes, particularly females that require blood meals for their fertilized eggs, are attracted to light during the day regardless of spectra. In contrast, night-biting mosquitoes specifically avoid ultraviolet (UV) and blue light during the day. Previous work in the Holmes lab using fruit flies (which are related to mosquitoes) has determined the light sensors and circadian molecular mechanisms for light mediated attraction/avoidance behaviors. Accordingly, molecular disruption of the circadian clock severely interferes with light-evoked attraction and avoidance behaviors in mosquitoes. At present, light-based insect controls do not take into consideration the day versus night behavioral profiles that change with daily light and dark cycles.

"Light is the primary regulator of circadian rhythms and evokes a wide range of time-of-day specific behaviors," said Holmes. "By gaining an understanding of how insects respond to short wavelength light in a species-specific manner, we can develop new, environmentally friendly alternatives to controlling harmful insects more effectively and reduce the need for environmentally damaging toxic pesticides."

Tiny finger-like projections called filopodia drive invasive behavior in a rare subset of lung cancer cells, researchers at Winship Cancer Institute of Emory University have found.

Adam Marcus' lab has developed innovative techniques for separating "leaders" and "followers," subpopulations of tumor cells that cooperate during the process of metastasis. The lab's new analysis of what molecular features distinguish leader from follower lung cancer cells focuses on filopodia. The results are published in Science Advances.

The findings could help researchers develop treatments that prevent cancer from spreading, by understanding the rare cells within a tumor necessary for deadly metastasis. The durable epigenetic changes that distinguish leader cells and invasive behavior may appear in several types of cancer, says Marcus. He is professor of hematology and medical oncology at Emory, and associate director for basic research and shared resources at Winship.

Marcus' previous research has shown how leader cells and their more common counterparts, follower cells, work together to create an invasive pack. The two types of tumor cells depend upon each other for mobility and survival, but have distinct patterns of gene activity and even different shapes.

In particular, leader cells display longer filopodia than follower cells. This is part of what the investigation by graduate student Emily Summerbell (who recently obtained her PhD), associate research scientist Janna Mouw, PhD and their colleagues revealed.

"Filopodia are like the fingers of the cell, and help the cell pull its way forward," Summerbell says. See the supplementary video S3 for a depiction of filopodia and invasive behavior.

Having longer filopodia is linked with a gene called MYO10, which encodes a component of the internal cellular skeleton stabilizing filopodia, Summerbell and Mouw found. MYO10 was the gene that was the most up-regulated and hypomethylated in leader cells, compared with follower cells, and both long filopodia and invasive behavior depend on MYO10 activity.

"It was known that MYO10 was linked to invasion and metastasis, but this is the first evidence that it is playing this specific role in a rare subset of cells," Marcus says. "This could help us look for these rare cells in patient tumors to gauge how potentially invasive they are."

Leader cells also secrete fibronectin, a sticky extracellular protein, while follower cells do not. The MYO10 protein helps filopodia rearrange fibronectin molecules into fibrils, but it does not appear to interact with fibronectin directly.

"As the leader cell filopodia pull on the extracellular matrix, they change this matrix from a random mesh into long parallel tracks in front of the cell, paving a road for a group of cells," Summerbell says.

Filopodia are sometimes described as resembling antennae - or precursors of more stable cellular structures.

"We're observing that in leader cells, filopodia are not only sensors of the extracellular environment but also actively participate in reorganizing the extracellular matrix," Marcus says.

Summerbell and Mouw also studied other changes that distinguish leader cells, such as elevated expression of the Jagged1 gene. Jagged1 encodes a receptor for the Notch pathway, whose activity lies behind activation of MYO10. MYO10 and Jagged/Notch activation may be generalizable to patient samples and other types of cancer.

HOUSTON - (July 27, 2020) - Materials scientists at Rice University and the University of Pennsylvania are calling for a collective, global effort to fast-track the mass production of 2D materials like graphene and molybdenum disulfide.

In a perspective article published online in Materials Today, journal editor-in-chief Jun Lou and colleagues make a case for a focused, collective effort to address the research challenges that could clear the way for large-scale mass production of 2D materials.

Lou and fellow Rice materials scientists Ming Tang, Jing Zhang and Fan Wang joined Penn's Vivek Shenoy in describing the potential transformation in 2D materials technology that could result from a systematic, communitywide effort to map the shapes of the 2D crystals that are being grown in labs worldwide via a process known as chemical vapor deposition (CVD).

"Like snowflakes in nature, 2D crystals exhibit a rich variety of morphologies under different growth conditions," they wrote.

Mapping these unique crystal patterns and compiling the maps in a global database, alongside the recipes for creating each pattern, could unlock a wealth of information "for understanding, diagnosing and controlling the CVD process and environment for 2D material growth," the researchers wrote.

CVD is a commonly used process for creating thin films, including commercially important materials in the semiconductor industry. In a typical CVD reaction, a flat sheet of material called a substrate is placed in a reaction chamber and gases are flowed through the chamber in such a way that they react and form a solid film atop the substrate.

One goal of the field is developing computer software that can accurately predict the properties of a thin film that will result from the mixing of specific reactant gases under specific conditions. Creating such models is complicated by both an incomplete understanding of the physical and chemical processes that take place during CVD and by the existence of dozens of CVD reactor formats.

Cataloging the shape of crystals produced by CVD experiments could provide materials scientists with important information about their synthesis, in much the same way that mineralogists retrieve valuable clues about the history of Earth based on examination of naturally occurring crystal structures, Lou and colleagues suggested.

"Take the beautiful snowflakes as an example," the authors wrote. "A perhaps surprising fact to many is that snow crystals can exhibit many different categories of shapes, which depend on the temperature and water supersaturation of the atmosphere in which they are formed."

The Japanese scientist Ukichiro Nakaya, through extensive observations of snowflakes in both nature and the laboratory, developed a figure known as the Nakaya diagram to help decipher the information in snowflakes. By examining the shapes in a snowflake, and seeing where those shapes lie on Nakaya's diagram, scientists can determine the exact atmospheric conditions that produced the snowflake, which Nakaya poetically referred to as "a letter from the sky."

Inspired by Nakaya's work, Lou and colleagues created a Nakaya-like diagram of 2D crystal patterns that have been produced via CVD and demonstrated how it and other morphology diagrams could be used to infer clues about process variables like gas flow rates and heating temperatures that produced each pattern.

Thanks to advances in real-time imaging and in automated systems that can produce large datasets of crystal structures, the authors said there is "real potential for morphology diagram development to become a common practice and serve as a cornerstone of crystal growth."

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Yokohama National University (YNU) uncover the peculiar mechanism by which spin perturbations travel through a seemingly unpassable region of a quantum spin liquid system. This new insight may represent another building block in next-generation electronics and even quantum computers.

Electronic devices as we know them are close to reaching their theoretical limits, meaning that radically new technology will be required to obtain better performance or higher miniaturization. The problem is that modern electronics is centered around manipulating electric currents and is therefore mainly concerned about the collective charge of moving electrons. But what if signals and data could be coded and sent in a more efficient way?

Enter spintronics, an emerging technological field envisioned to revolutionize electronics and, hopefully, become a key player in the development of quantum computers. In spintronic devices, the most important characteristic of electrons is their spin, an intrinsic property that can be broadly seen as their angular momentum and that is the underlying cause of magnetic phenomena in solids. However, physicists worldwide are struggling to find practical ways to generate and transport 'spin packets' through materials. In a recent study, scientists at Tokyo Tech and YNU, Japan, conducted a theoretical analysis of the peculiar spin transport characteristics of a particular system called the 'Kitaev model'.

This two-dimensional model comprises a honeycomb network where each vertex hosts a spin. What's special about the Kitaev system is that, because of the peculiar interactions between spins, it behaves as a quantum spin liquid (QSL). This broadly means that it is impossible in this system for spins to be arranged in a unique optimal way that 'keeps every spin happy.' This phenomenon, called spin frustration, causes spins to behave in a particularly disordered fashion. Professor Akihisa Koga, who led the study, says: "The Kitaev model is an interesting playground for studying QSLs. However, not much is known about its intriguing spin transport properties."

An important characteristic about the Kitaev model is that it has local symmetries; such symmetries mean that spins are correlated only with their nearest neighbors and not with far-away spins, thus implying that there should be a barrier to spin transport. However, in reality, small magnetic perturbations on one edge of a Kitaev system do manifest as changes in the spins at the opposite edge, even though the perturbations do not seem to cause any changes in the magnetization of the central, more symmetrical region of the material. This intriguing mechanism is what the team of scientists clarified in their study, which is published in Physical Review Letters.

They applied an impulse magnetic field on one edge of a Kitaev QSL to trigger 'spin packet' transport and numerically simulated the real-time dynamics that consequently unfolded. It turns out that the magnetic perturbation is carried across the central region of the material by travelling 'Majorana fermions.' These are quasiparticles; they are not real particles but precise approximations of the collective behavior of the system.

Notably, Majorana-mediated spin transport cannot be explained by classic spin-wave theory and therefore warrants further experimental studies. But Koga is hopeful of the application potential of the results of this study. He says: "Our theoretical results should be relevant in real materials as well, and the setup of our study could be implemented physically in certain candidate materials for Kitaev systems."

In their article, the scientists discuss possible materials, ways of creating the spin perturbations, and ways to experimentally find evidence of the Majorana fermions travelling through the bulk of the material to reach the other edge. It may even be possible to control the motion of the static (non-travelling) Majorana fermions in the system, which could be of practical use. Only time will tell how many more mysteries of the quantum world physicists will solve and how we will benefit from them.

Death Valley doesn't seem like the most ideal place to ride out rising temperatures amid a changing climate. But for the desert plants that live there, it's home--and they face the choice to adapt or die.

Research from the University of Utah shows that one shrub, the brittlebush, is adapting, and showing a remarkable ability to respond to increased temperature and aridity. The research is published in Proceedings of the National Academy of Sciences and was funded by the National Science Foundation.

"We were able to directly relate changes in plant ecophysiology to changing climate over a relatively short timescale," says study lead author and laboratory technician Avery Driscoll.  "This shows us that desert shrubs can and do acclimate to changing environmental conditions."

Forty years in the desert

Data for this study came from two long-term research sites in the remote deserts of the American Southwest--one in Death Valley and the other near Oatman, Arizona, both with an area of a few hundred square meters. The sites were established in the early 1980s by U distinguished professor of biology Jim Ehleringer, who recognized both the value of long-term observations, and the appeal of traveling somewhere warm during Salt Lake City's cold months. Every spring for nearly 40 years, Ehleringer and members of his lab have visited the research sites to survey the vegetation and collect samples of plants for later analysis.

In 2020, a scaled-down and postponed survey trip still went forward. "Easy to distance when working in the wide-open of the Mojave," tweeted co-author Darren Sandquist.

The study focuses on one shrub species in particular: Encelia farinosa, also called brittlebush or incienso. It can live more than 30 years and is found widely throughout the Southwest and northern Mexico, with bright yellow flowers and silvery leaves.

Biologists who study forests have a readily accessible climate record in tree rings. But in environments with few trees, they need another method. Brittlebush leaves, collected over time, contain their own climate record in the isotopes of carbon that make up the leaf tissue. Isotopes are atoms of the same element that differ in weight by only a neutron or two. Many isotopes are stable, i.e. non-radioactive, and their slight difference in mass can be reflected in physical or physiological processes.

In this case, the isotopes of carbon in the brittlebush leaves reflected how wide the plants were opening their stomata, small pores on the underside of their leaves. Plants open stomata to take in more carbon dioxide, but at the risk of losing water vapor. So the isotopes can yield the plant's water use efficiency, or the balance between the amount of water lost and the rate of photosynthesis.

Adapting for efficiency

The results show that the brittlebushes increased their water use efficiency by 53-58% over the 39-year study period. That's remarkably high, nearly double the increase in efficiency in forests over the same time period.

Temperature is rising and humidity is decreasing in the Mojave Desert, Driscoll says. "This increase in water-use efficiency shows that the leaf physiology of these plants has adjusted in response to this added water stress and increased availability of CO2."

Researchers have proposed that increasing CO2 levels may be a benefit to plants like the brittlebush, allowing it to get the same amount of CO2 with smaller stomatal openings, reducing water loss. So far, though, forests haven't demonstrated an increase in growth along with an increased water use efficiency.

"While we can't say anything about the implications for shrub growth," Driscoll says, "we did find that increases in water-use efficiency were substantially larger in deserts than they are in forests."

The researchers observed increased water use efficiency in some plants that had been sampled throughout the entire study period, showing acclimation by individuals, as well as by the whole shrub population, to changing conditions.

These shrubs can have lifespans of 30+ years and establishment of new plants occurs infrequently," Driscoll says, "so we can't rule out the possibility that generational changes will also occur if the populations are observed over longer timescales."

So does this finding mean that the brittlebush and other desert shrubs will be able to weather future warming? We can't yet say, Driscoll says.

"While it's possible that more efficient use of water could translate into growth, survival or flowering benefits for these plants, we don't yet know if the change will confer advantages or mitigate potential declines in the population."

After publication, find the full study here.

By tuning into a subset of brain waves, University of Michigan researchers have dramatically reduced the power requirements of neural interfaces while improving their accuracy--a discovery that could lead to long-lasting brain implants that can both treat neurological diseases and enable mind-controlled prosthetics and machines.

The team, led by Cynthia Chestek, associate professor of biomedical engineering and core faculty at the Robotics Institute, estimated a 90% drop in power consumption of neural interfaces by utilizing their approach.

"Currently, interpreting brain signals into someone's intentions requires computers as tall as people and lots of electrical power--several car batteries worth," said Samuel Nason, first author of the study and a Ph.D. candidate in Chestek's Cortical Neural Prosthetics Laboratory. "Reducing the amount of electrical power by an order of magnitude will eventually allow for at-home brain-machine interfaces."

Neurons, the cells in our brains that relay information and action around the body, are noisy transmitters. The computers and electrodes used to gather neuron data are listening to a radio stuck in between stations. They must decipher actual content amongst the brain's buzzing. Complicating this task, the brain is a firehose of this data, which increases the power and processing beyond the limits of safe implantable devices.

Currently, to predict complex behaviors such as grasping an item in a hand from neuron activity, scientists can use transcutaneous electrodes, or direct wiring through the skin to the brain. This is achievable with 100 electrodes that capture 20,000 signals per second, and enables feats such as reenabling an arm that was paralyzed or allowing someone with a prosthetic hand to feel how hard or soft an object is. But not only is this approach impractical outside of the lab environment, it also carries a risk of infection.

Some wireless implants, created using highly efficient, application-specific integrated circuits, can achieve almost equal performance as the transcutaneous systems. These chips can gather and transmit about 16,000 signals per second. However, they have yet to achieve consistent operation and their custom-built nature is a roadblock in getting approval as safe implants compared to industrial-made chips.

"This is a big leap forward," Chestek said. "To get the high bandwidth signals we currently need for brain machine interfaces out wirelessly would be completely impossible given the power supplies of existing pacemaker-style devices."

To reduce power and data needs, researchers compress the brain signals. Focusing on neural activity spikes that cross a certain threshold of power, called threshold crossing rate or TCR, means less data needs to be processed while still being able to predict firing neurons. However, TCR requires listening to the full firehose of neuron activity to determine when a threshold is crossed, and the threshold itself can change not only from one brain to another but in the same brain on different days. This requires tuning the threshold, and additional hardware, battery and time to do so.

Compressing the data in another way, Chestek's lab dialed in to a specific feature of neuron data: spiking-band power. SBP is an integrated set of frequencies from multiple neurons, between 300 and 1,000 Hz. By listening only to this range of frequencies and ignoring others, taking in data from a straw as opposed to a hose, the team found a highly accurate prediction of behavior with dramatically lower power needs.

Compared to transcutaneous systems, the team found the SBP technique to be just as accurate while taking in one-tenth as many signals, 2,000 versus 20,000 signals per second. Compared to other methods such as using a threshold crossing rate, the team's approach not only requires much less raw data, but is also more accurate at predicting neuron firing, even among noise, and does not require tuning a threshold.

The team's SBP method solves another problem limiting an implant's useful life. Over time, an interfaces' electrodes fail to read the signals among noise. However, because the technique performs just as well when a signal is half of what is required from other techniques like threshold crossings, implants could be left in place and used longer.

While new brain-machine interfaces can be developed to take advantage of the team's method, their work also unlocks new capabilities for many existing devices by reducing the technical requirements to translate neurons to intentions.

"It turns out that many devices have been selling themselves short," Nason said. "These existing circuits, using the same bandwidth and power, are now applicable to the whole realm of brain-machine interfaces."

The study, "A low-power band of neuronal spiking activity dominated by local single units improves the performance of brain-machine interfaces," is published in Nature Biomedical Engineering.

What The Study Did: Changes over 25 years in how common spanking of children was by parents in the United States are examined in this study.

Authors: Christopher J. Mehus, Ph.D., L.M.F.T., of the University of Minnesota in Minneapolis, is the corresponding author.

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

(doi:10.1001/jamapediatrics.2020.2197)

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

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Media advisory: The full study is linked to this news release.

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Graphene, an atomically thin hexagonal structure of carbon atoms is a potential candidate for electronic and optoelectrical applications such as transparent electrodes and interconnect for integrated circuits. Yet, it is one thing to possess such useful properties and to induce an intended characteristic from this "wonder material" is another. In the face of the end of the "Moore's Law", chip makers have set their sight on multi-layered graphene for its scaling ability of integrated circuits to smaller physical dimensions and the electric-field induced bandgap, which is not affordable in monolayer graphene. Furthermore, owning to exotic physical properties controlled by its stacking orders (the arrangement of graphene layer along vertical direction) such as superconductivity and quantum Hall effect to name a few, multi-layer graphene is an interesting material for condensed matter physicists. Still, the unknown growth method for uniform single-crystalline multilayer graphene growth in a wafer scale presents a challenge.

Led by professor LEE Young Hee at the Center for Integrated Nanostructure Physics, the Institute for Basic Science (IBS) in Sungkyunkwan University, South Korea, an IBS research team reports a novel method to grow multi-layered, single-crystalline graphene with a selected stacking order in a wafer scale. They obtained four-layered graphene using chemical vapor deposition (CVD) via Cu-Si alloy formation.

There have been several approaches to control the number of graphene layers. Conventionally, the monolayer graphene, which is easily grown on Cu-substrate, can be detached from the Cu-substrate and transferred onto insulator substrates such as SiO2/Si. Therefore, the simplest method to make multilayer graphene is to stack them layer-by-layer via the transfer process. However, this transfer process may cause tearing, wrinkles, and/or polymer residues. Though such issues can be avoided via a direct method, i.e. CVD on Cu substrate, the low solubility of carbon (C) in copper (Cu) hampers the controlling of the number of graphene layers with high uniformity in a large area. By depositing Ni or Co to form Cu-Ni/ Cu-Co alloys or employing oxygen-rich Cu substrate, C solubility in Cu is boosted and thus stacks more layers of graphene. Nevertheless, a small portion of inhomogeneous multilayers occurs. Controlling the crystallographic stacking sequence of graphene films thicker than two layers with high uniformity has not been demonstrated to date.

Dr. Van Luan Nguyen, the first author of the study (now at Samsung Advanced Institute Technology) proposed to use silicon carbide (SiC) on the surface of Cu substrate alloy, via the sublimation of Si atoms at a high temperature. They controlled the C solubility in the Cu film by introducing Si content on Cu surface by heat treatment of Cu substrate with a constant H2 gas flow inside the quartz tube of CVD chamber. "The formation of a homogeneous Cu-Si alloy, as a role of catalyst, was critical to control the number layers of graphene film in a wafer scale with methane gas. With the presence of Cu-Si alloy, SiC can be formed when methane gas is injected and the following sublimation process of Si atoms leaves C atoms behind to form multilayer graphene. Si amount is fixed at 28.7 % for uniform multilayer graphene film. Depending the concentrations of argon (Ar)-diluted methane gas, the number of graphene layers varies," says Dr. Van.

Growing in a large scale of this much-hyped graphene has seen much progress over a decade, but building multi-layered graphene is just in its early stages. Our study offers a novel approach to upgrade the conventional CVD method by introducing an intermediate process of in-situ formation of SiC film," notes Dr. LEE Sang Hyub, coauthor of the study. Importantly, this study provides a new platform to synthesize graphene multilayer towards the uniform large-area single-crystalline layer-tunable multilayer graphene as well as graphite thin film. This is an initial step to incorporate multilayer graphene to display panels and integrated circuits such as via-holes and replacement of Cu electrodes as well as photoelectronic and photovoltaic devices.

"Deposition of Si by conventional methods at low temperatures such as thermal evaporation or sputtering does not work for uniform multilayer graphene growth. The key in our new approach is to form uniform Cu-Si alloy on quartz tube chamber in which Si is sublimated at high temperature of 900 ? with H2 gas flow in a controllable manner," explains Director LEE Young Hee, the corresponding author of the study. Although the substantial achievement has been demonstrated in our current work, Director Lee cautions that the method to deposit Si at high temperature during the growth process is not practical and can be harmful for the quart tube for long-term use. They are searching for a solution to replace the current one for mass product.

Topology, which is a branch of mathematics, is rising as a universal notion in physics, from condensed matter physics to classical wave systems. Topology has been received particularly warmly in photonics and has spawned a new field called topological photonics. Over the past decade, topological photonics has undergone surprisingly rapid development. Researchers in topological photonics have realized physical phenomena that have only been predicted so far in other fields and have even discovered new phenomena for the first time ever.

In a new review article published in Light: Science & Applications, a team of scientists, led by Professor Junsuk Rho from POSTECH, South Korea have reviewed the recent progress of topological photonics. In the review article, they focus on three-dimensional photonic topological phases and the latest findings that have yet to be reviewed. Starting by emphasizing the importance the implementation of topology in photonics, they provide the general concepts of topological band theory and two-dimensional phases and introduce the numerous approaches to realizing 3D photonic topological phases using photonic crystals and metamaterials. The recently emerging fields including, but not limited to, layer pseudospin, Weyl degeneracies with nonzero dimension, Maxwellian spin waves, and higher-order topological photonics are all reviewed. Finally, their perspectives of the outlook of topological photonics are given.

The team describe the power of topology as:

"A physical phenomenon that is characterized by topology is not affected by any continuous deformation. Then light can flow through a topological device by even if there are defects or impurities."

"The merger of topology and photonics is mutually beneficial to each other. Photonics serves as a concrete platform to test and realize theories of topological physics, and topology enables robust control of electromagnetic waves even in imperfect devices. The advances in topological photonics may realize some fascinating applications that have been impossible in conventional photonics such as lossless waveguides." They added.

"As in the past decade, the advances of topological photonics will continue. The scope of the topological photonics is diversifying, covering nonlinearity, non-Hermiticity, and higher-dimensions and will be further broadened by being combined with interdisciplinary fields." The scientists forecast.

Deep learning applied for image/video processing opened the door for the practical deployment for object detection and identification with acceptable accuracy. Crowd counting is another application of image/video processing. The scientists at Japan Advanced Institute of Science and Technology (JAIST) designed a new DNN with backward connection, which achieved more accurate estimation of the density of objects. It can be applied for estimating human density in the public or vehicle density on a road in order for improving public safety/security and traffic efficiency.

Video surveillance is one of the standard ways for obtaining information to detect the status of objects. For example, video surveillance employed on a road is monitored to obtain the information on the flow of traffic, occurrence of accident, and/or the density of the vehicle for the purpose of improving security, safety, and/or efficiency of traffic. Another example of video surveillance is human traffic in the public. Monitoring the flow and the density of the people is mandatory to assure the safety of public places, especially for indoor environment.

Obtaining the information of the density or the number of objects, such as vehicles or people, is called crowd counting. Crowd counting with higher accuracy will offer more seamless control of ITS with less 'jaggy' feedback, or will detect serious status of human congestion that may cause accidents properly. The research group in JAIST led by Dr. Sooksatra and Prof. Atsuo Yoshitaka in collaboration with a research group of SIIT in Thailand proposed a new network employing backward connections in DNN, which achieved higher performance in crowed computing.

"Backward connection in DNN enables to take advantages obtained from both high-level feature and low-level feature in an image, and therefore achieves higher performance than before" says Prof. Atsuo Yoshitaka, the head of Yoshitaka Lab. The Yoshitaka lab. is currently developing different kind of DNNs for industrial applications such as object detection/identification of objects in micrograph, defect detection for industrial products, and DNA analysis for automated diagnosis.

Researchers at Linköping University's Department of Thematic Studies, Environmental Change, have developed a simple logger for greenhouse gas flows. It is built using inexpensive and easily available parts, and provides data on levels of methane, carbon dioxide, temperature and humidity.

"So far, measurement instruments have been so expensive that society's mapping of greenhouse gas emissions has had to rely on rough models. It's extremely important that we can make lots of proper measurements locally, so we can test whether measures for reducing emissions actually work. We hope that our simple and cost-efficient logger can contribute to more such measurements" says David Bastviken, professor at Environmental Change, and author of an article in Biogeoscience.

A current limitation when it comes to determining the greenhouse gas fluxes has been the lack of reliable low-cost measurement methods that can be widely available in society. In 2015, David Bastviken and colleagues described and published a logger for carbon dioxide, which is now used for various types of environmental measurements. However for methane, more complicated and expensive measurement equipment has so far been required. In the current article in Biogeoscience, the researchers describe an inexpensive sensor for methane.

Methane, CH4, is one of the most important long-lived greenhouse gases which contributes greatly to global warming. Since the 1750s, its relative increase in the atmosphere has been greater than for other greenhouse gases. There are many different sources and examples including incomplete combustion, handling of natural gas and biogas, and microbial production in agriculture, wetlands and lakes. However the large number of sources that can vary greatly in ways not fully understood makes it difficult to quantify fluxes and to propose best practices for flux mitigation. In addition, the discovery that lakes, rivers and flooded forests are large sources of methane, made by David Bastviken and his colleagues as recently as 2011 and later, shows that major methane sources are still being discovered.

"We have now built and tested a simple logger based on the open-source Arduino hardware. The parts are available in many electronics stores; they can be ordered online and cost about 200 euro. We have also developed more precise ways to calibrate the methane sensor, to enable the measurement of greenhouse gas fluxes at a very low cost", says David Bastviken.

The researchers hope that the logger will make it easier for all interested, and in e.g. education and environmental monitoring, to monitor greenhouse gas emissions.

"We also propose simplified but satisfactory ways to calibrate the sensors that don't require continuous access to advanced research laboratories. This can make measurements easier, for instance in developing countries", says David Bastviken.

Infertility affects between 10 and 15% of all couples of reproductive ages and can be caused by a wide variety of factors: genetic, physiological, environmental and nutritional.Although there is increasing scientific evidence about the role of nutrition in sperm quality, there is still controversy about the role of overweight, obesity and low weight in sperm parameters.

Researchers from the Human Nutrition Unit of the Rovira i Virgili University and the CIBERobn in collaboration with researchers from the University of Utah (USA), researchers from the Ahvaz Jundishapur University and the National University of Córdoba (Argentina),have carried out a systematic review and meta-analysis of all the existing observational scientific literature, evaluating the association between adiposity(normal weight, overweight, obesity, and low weight) and the sperm quality determined by a seminogram.

A total of 60 articles were included in the qualitative analysis and 28 in the quantitative analysis. The researchers indicated that overweight and/or obesity were associated with low semen quality parameters (i.e., semen volume, sperm count and concentration, sperm vitality, total motility and normal morphology) and underweight category was likewise associated with low sperm normal morphology.

According to the researchers, this work provides the most comprehensive analysis to date of the high-quality research and demonstrates the importance of adiposity in semen quality.

Albert Salas-Huetos, first author of the article states that these results "suggest that overweight/obesity prevention should be considered at an early age to avoid deleterious effects on reproductive health". Researchers also point out that additional studies are warranted to elucidate thepotential benefits of weight loss for improving reproductive potential in individuals with obesity.

The results of the present study, conducted by the post-doctoral researcher Dr. Albert Salas-Huetos, currently working at the University of Utah, in collaboration with researchers from the Human Nutrition Unit of the Rovira i Virgili University and the CIBERobn led by Professor Jordi Salas-Salvadó, have been published in the prestigious scientific journal Obesity Reviews. It is one of the most impactful scientific journals in the Endocrinology and Metabolism area.

Cicadas infected with the parasitic fungus Massospora unknowingly engage in trickery with their fellow insects, resulting in effective disease transmission, according to West Virginia University-led research.

Massospora manipulates male cicadas into flicking their wings like females – a mating invitation – which tempts unsuspecting male cicadas and infects them.

It’s a recent discovery into the bizarre world of cicadas plagued by a psychedelic fungus that contains chemicals including those found in hallucinogenic mushrooms. The research, “Behavioral betrayal: How select fungal parasites enlist living insects to do their bidding,” was published in the journal PLOS Pathogens.

“Essentially, the cicadas are luring others into becoming infected because their healthy counterparts are interested in mating,” said Brian Lovett, study co-author and post-doctoral researcher with the Davis College of Agriculture, Natural Resources and Design. “The bioactive compounds may manipulate the insect to stay awake and continue to transmit the pathogen for longer.”

These actions persist amid a disturbing display of B-horror movie proportions: Massospora spores gnaw away at a cicada’s genitals, butt and abdomen, replacing them with fungal spores. Then they “wear away like an eraser on a pencil,” Lovett said.

Lovett compared the transmission of the behavior-modifying virus to rabies.

Both rabies and entomopathogenic fungi (parasites that destroy insects) enlist their living hosts for successful “active host transmission,” Lovett said.

“When you're infected with rabies, you become aggressive, you become afraid of water and you don't swallow,” Lovett said. “The virus is passed through saliva and all of those symptoms essentially turn you into a rabies-spreading machine where you're more likely to bite people.

“In that sense, we're all very familiar with active host transmission. Since we are also animals like insects, we like to think we have complete control over our decisions and we take our freewill for granted. But when these pathogens infect cicadas, it's very clear that the pathogen is pulling the behavioral levers of the cicada to cause it to do things which are not in the interest of the cicada but is very much in the interest of the pathogen.”

Lovett’s colleague and paper co-author, Matthew Kasson, associate professor of plant pathology and mycology, helped first discover the existence of psychoactive compounds in Massospora-infected cicada fungi last year.

“Our previous literature always mentioned the strange behaviors associated with Massospora and some closely-allied fungi but what was missing was a synthesis of all this new information that had come to light,” Kasson said. “The most interesting finding is the things we still don't know. We realized that there were some possible scenarios for infection that we had not considered before.”

Kasson noted that it’s generally accepted that cicada nymphs encounter Massospora in their 17th year as they emerge from the ground to molt into adults. But researchers also concluded that nymphs could encounter Massospora on their way down to feed on roots for 17 years.

“The fungus could more or less lay in wait inside its host for the next 17 years until something awakens it, perhaps a hormone cue, where it possibly lays dormant and asymptomatic in its cicada host,” Kasson said.

Working alongside Lovett and Kasson was doctoral student Angie Macias, who believes their research will lead to a better overall understanding of insects.

“These discoveries are not only super cool but also have a lot of potential in helping us understand insects better, and perhaps learn better ways to control pest species using fungi that manipulate host behaviors,” she said. “It is almost certain that there are undiscovered Massospora species, never mind the other AHT (active host transmission) fungi, and each of these will have developed its own intimate connection with its host's biology.”

The team managed to research cicada broods earlier this year in southeastern West Virginia.

Lovett also explained why we’re seeing cicadas emerging again so soon.

“Different broods come out at different time spans,” he said. “There’s our periodical cicadas that come out every 13 years and there are other periodical cicadas that come out every 17 years. The timing is staggered in different states.”

And, as grotesque as an infected decaying cicada sounds, they’re generally harmless to humans, he said. They also reproduce at such a rate that the fungi’s extermination of hordes of cicadas has little effect on their overall population.

“They're very docile,” Lovett said. “You can walk right up to one, pick it up to see if it has the fungus (a white to yellowish plug on its back end) and set it back down. They’re not a major pest in any way. They’re just a really interesting quirky insect that’s developed a bizarre lifestyle."

Citation: “Behavioral betrayal: How select fungal parasites enlist living insects to do their bidding”

Journal

PLoS Pathogens

Naturally occurring lithium in public drinking water may have an anti-suicidal effect - according to a new study from Brighton and Sussex Medical School (BSMS) and the Institute of Psychiatry, Psychology & Neuroscience at King's College London.

Published in the British Journal of Psychiatry, the study collated research from around the world and found that geographical areas with relatively high levels or concentration of lithium in public drinking water had correspondingly lower suicide rates.

Professor Anjum Memon, Chair in Epidemiology and Public Health Medicine at BSMS and lead author of the study, said: "It is promising that higher levels of trace lithium in drinking water may exert an anti-suicidal effect and have the potential to improve community mental health. The prevalence of mental health conditions and national suicide rates are increasing in many countries. Worldwide, over 800,000 people die by suicide every year, and suicide is the leading cause of death among persons aged 15-24 years."
 

"In these unprecedented times of COVID-19 pandemic and the consequent increase in the incidence of mental health conditions, accessing ways to improve community mental health and reduce the incidence of anxiety, depression and suicide is ever more important." 
 

Lithium, sometimes referred to as the 'Magic Ion', is widely and effectively used as a medication for the treatment and prevention of manic and depressive episodes, stabilising mood and reducing the risk of suicide in people with mood disorders. Its anti-aggressive properties can help reduce impulsivity, aggression, violent criminal behaviour and chronic substance abuse.

Lithium is a naturally occurring element and is found in variable amounts in vegetables, grains, spices and drinking water. It is present in trace amounts in virtually all rocks, and is mobilised by weathering into soils, ground and standing water, and thus into the public water supply.

The health benefits and curative powers of naturally occurring lithium in water have been known for centuries. The Lithia Springs, an ancient Native American sacred medicinal spring, with its natural lithium-enriched water, is renowned for its health-giving properties. In fact, the popular soft drink 7-Up contained lithium when it was created in 1929.

Recent studies have also linked lithium to reduced incidence of Alzheimer's disease and other dementias. This raises the potential for its preventative use to combat the risk of dementia.

Professor Allan Young, Chair of Mood Disorders at King's College London, said: "This synthesis and analysis of all available evidence confirms previous findings of some individual studies and shows a significant relationship between higher lithium levels in drinking water and lower suicide rates in the community. The levels of lithium in drinking water are far lower than those recommended when lithium is used as medicine although the duration of exposure may be far longer, potentially starting at conception. These findings are also consistent with the finding in clinical trials that lithium reduces suicide and related behaviours in people with a mood disorder."

Professor Memon added: "Next steps might include testing this hypothesis by randomised community trials of lithium supplementation of the water supply, particularly in communities (or settings) with demonstrated high prevalence of mental health conditions, violent criminal behaviour, chronic substance abuse and risk of suicide. This may provide further evidence to support the hypothesis that lithium could be used at the community level to reduce or combat the risk of these conditions."

Professor Carmine Pariante from the Royal College of Psychiatrists, commented: "This study shows that the boundaries between medication and nutritional interventions are not as rigid as we used to think, opening up the possibility of new treatments that span both domains. More knowledge of the beneficial properties of lithium and its role in regulating brain function can lead to a deeper understanding of mental illness and improve the wellbeing of patients with depression and other mental health problems."
 

The study involved systematic review and meta-analysis of all previous studies on the subject - conducted in Austria, Greece, Italy, Lithuania, UK, Japan and USA - which correlated naturally occurring lithium levels in drinking water samples and suicide rates in 1,286 regions/counties/cities in these countries.

The simplicity and elegance of origami, an ancient Japanese art form, has motivated researchers to explore its application in the world of materials.

New research from an interdisciplinary team, including Northwestern Engineering's Horacio Espinosa and Sridhar Krishnaswamy and the Georgia Institute of Technology's Glaucio Paulino, aims to advance the creation and understanding of such folded structures for applications ranging from soft robotics to medical devices to energy harvesters.

Inspired by origami, mechanical metamaterials -- artificial structures with mechanical properties defined by their structure rather than their composition -- have gained considerable attention because of their potential to yield deployable and highly tunable structures and materials.

What wasn't known was which structures integrate shape recoverability, pronounced directional mechanical properties, and reversible auxeticity--meaning their lateral dimensions can increase and then decrease when progressively squeezed. Though some 3D origami structures have been produced through additive manufacturing, achieving the folding properties displayed in ideal paper origami remained a challenge.

Using nanoscale effects for an origami design, the team of researchers from the McCormick School of Engineering and Georgia Tech sought to answer that question. They produced small, 3D, origami-built metamaterials, successfully retaining the best properties without resorting to artifacts to enable folding.

"The created structures constitute the smallest fabricated origami architected metamaterials exhibiting an unprecedented combination of mechanical properties," said Espinosa, the James and Nancy J. Farley Professor of Manufacturing and Entrepreneurship and professor of mechanical engineering and (by courtesy) biomedical engineering and civil and environmental engineering.

"Our work demonstrated that rational design of metamaterials, with a large degree of shape recoverability and direction-dependent stiffness and deformation, is possible using origami designs, and that origami foldability enables a state where the material initially expands and subsequently contracts laterally (reversible auxeticity)," added Espinosa, who serves as director of Northwestern's Theoretical and Applied Mechanics graduate program. "Such properties promise to influence a number of applications across a wide range of fields encompassing the nano-, micro-, and macro-scales, leveraging the intrinsic scalability of origami assemblies."

"Guided by geometry, the scaling and miniaturization of the origami metamaterial are exciting in itself and by the unprecedented multifunctionality that it naturally enables," said Paulino, the Raymond Allen Jones Chair at Georgia Tech's School of Civil and Environmental Engineering.

"Only an interdisciplinary effort combining origami design, 3D laser printing with nanoscale resolution, and in situ electron microscopy mechanical testing could reveal the unprecedented combination of properties our work demonstrated and their potential impact on future applications," added Paulino, who contributed to establishing the National Science Foundation Emerging Frontiers in Research and Innovation program named ODISSEI (Origami Design for Integration of Self-assembling Systems for Engineering Innovation).

"Just like nature has architected a wide range of structures using just a few material systems, origami allows us to engineer resilient structural components with distinct physical properties along different directions," said Krishnaswamy, professor of mechanical engineering.

"We can envision origami-based soft microrobots that are stiff along some directions to carry payloads while maintaining other degrees of flexibility for motion. Origami-metamaterials that exploit reversible auxeticity and large deformation can lead to multifunctional applications ranging from deployable microsurgical instruments and medical devices, to energy steering and harvesting," added Krishnaswamy, the director of Northwestern's Center for Smart Structures and Materials.

The study presents new avenues to be explored long term, Espinosa said.

"There are a number of possibilities," he said. "One is the fabrication of origami structures with ceramic and metallic materials, while preserving nanoscale dimensions, to exploit size effects in the mechanical response of the structures leading to superior energy dissipation per unit volume and mass. Another is the use of piezoelectric polymers, which can result in energy harvesters that can drive sensing modalities or power microsurgical tools."