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AUGUST 24, 2020, NEW YORK - Researchers led by Ludwig Chicago Co-director Ralph Weichselbaum and Ronald Rock of the University of Chicago have identified in preclinical studies a potential drug target for curtailing cancer metastasis.

Their study, published in the Proceedings of the National Academy of Sciences, describes how a compound named 4-hydroxyacetophenone (4-HAP) activates a specific protein motor in cells and so monkey-wrenches biomechanical processes essential to cell motility. It also demonstrates in a mouse model that targeting this protein motor undermines the metastasis of colon cancer cells.

"Metastasis is a major problem in cancer and accounts for about 90% of cancer deaths," said Weichselbaum. "The overall goal here was to find something that reduces the metastatic burden to improve outcomes of cancer therapy."

For a cancer cell to establish a metastatic growth, it must first break out of the tumor in which it resides, slip into a blood or lymph vessel, drift to a new region of the body, climb out of the vessel, creep into another organ and plant itself firmly in the new tissue. To do all that, it has to squeeze, wriggle and crawl through the molecular stuffing between the cellular layers of various tissues. Each step of metastasis thus requires a good deal of shape shifting, which is accomplished by molecular motors that reorganize the dynamic protein skeleton of the cell and drive the cellular protrusions--or lamellipodia--that enable its crawl.

Researchers have long sought to block metastasis by targeting the biochemical signaling pathways that switch on these processes. Such efforts have, however, been met with limited success because multiple signaling pathways control cell motility, and cancer cells invariably find ways around the blockade of any one pathway.

The researchers thus turned their attention to the recipients of all those signals--the protein motors that dynamically remodel the protein skeleton of the migrating cell. Among these are a set of protein motors known as non-muscle myosins, which are critical to establishing the shape of a cell, anchoring it in place and forming and stretching its lamellipodia as it crawls.

In the current study, the researchers first established in cell culture experiments that 4-HAP disrupts the ability of colon cancer cells to invade, migrate and plant themselves at new sites.

Co-authors on the paper at Johns Hopkins University had previously shown that the molecule inhibits the motility of pancreatic cancer cells by targeting nonmuscle myosins. In an elegant series of subcellular molecular tracking experiments, Rock's lab demonstrated that 4-HAP specifically exerts its effects through the activation of non-muscle myosin 2 (NM2C).

NM2C helps control the stiffness of cells and organizes components of the cellular skeleton known as actin filaments. Weichselbaum, Rock and colleagues hypothesize that NM2C's abnormal activation essentially freezes it on certain types of actin filaments, gumming up the machinery of cellular motility.

The researchers also show that when colon cancer cells are injected into the spleen in a mouse model for liver metastasis, dosing the animals with 4-HAP significantly reduces the burden of tumors in the liver compared to untreated counterparts.

"Our next step is going to be to combine NM2C activation in animals with radiotherapy or chemotherapy," says Weichselbaum. "We're excited because, although 4-HAP is not suited to human use, we have shown that NM2C is likely to be a druggable target for the control of metastasis."

The researchers also plan to evaluate other non-muscle myosins as potential drug targets and pin down the precise mechanisms by which NM2C activation disrupts cellular motility.

Older adults living in very rural settings are less likely than those living closer to urban centers to receive available services in health, nutrition and transportation, according to a new study by a Washington State University scientist.

Raven Weaver, assistant professor in WSU's Department of Human Development, and her coauthor Karen Roberto at Virginia Tech, found that older adults living in a completely rural environment, far from a city center, are two and a half times less likely to receive any type of service compared to those living in a mostly rural setting.

The findings were published today in The International Journal of Aging and Human Development.

Services, in the paper, include meal delivery programs, farmer's market voucher assistance, various types of in-home care, health management programs, transportation services, and many others. Older adults are defined as anyone over 60 years old.

While service disparities between rural and urban older adults are well known, these findings distinguish between different levels of rural.

"We know that people living in rural areas receive fewer services," Weaver said. "Rural residents have the same level of need as urban older adults. Our paper highlights the most vulnerable groups within that rural classification."

For the study, Weaver used data from more than 1,600 adults, collected from Area Agencies on Aging in Virginia. Those agencies often provide or refer people to the services mentioned above, and are designed to support older adults proactively, Weaver said.

When looking through all the data, geography was the most significant disparity.

"Where people lived influenced what services they got more than their needs or disabilities," Weaver said.

Given the current Covid-19 pandemic, the findings of this paper could be exacerbated, she said.

"The lack of direct personal contact, not receiving health checkups, those are increasing with COVID and social distancing," Weaver said. "This study shows where the biggest holes are in the systems aimed at helping older adults age in place."

It is important for families caring for older adults to realize they can contact agencies about services for their relatives, Weaver said.

"Get connected to services early," she tells families. "Some support is better than no support. Having access to food or meal assistance can re-direct energy to other challenges. Being proactive is key for helping people remain in their homes as they get older."

PHILADELPHIA - Jefferson researchers developing a cancer vaccine to prevent recurrences of gastric, pancreatic, esophageal and colon cancers have added a component that would make the vaccine more effective. The change makes the vaccine less prone to being cleared by the immune system before it can generate immunity against the tumor components. The preclinical studies pave the way for a phase II clinical trial opening to patients this fall.

"Our data show strong immune responses in mice that might otherwise clear the vaccine, and suggests this approach will be more effective in the human trials we are starting shortly," says Adam Snook, PhD, assistant professor in the Department of Pharmacology and Experimental Therapeutics and researcher at the NCI-Designated Sidney Kimmel Cancer Center (SKCC)--Jefferson Health, a top ranked cancer center.

The research was published in Journal of ImmunoTherapy of Cancer on August 20, 2020.

Many vaccine targets, such as a tumor antigen or circulating virus, are introduced to the immune system through a "broker," -- a safe negotiator of immunity. That broker introduces the vaccine components to the immune system, triggering a strong immune reaction needed for immunity, while protecting a person from the original threat - the cancer or disease-causing virus. Many vaccines, including some COVID-19 candidate vaccines, are often built using a strain of adenovirus as that broker or carrier.

Adenovirus is a common choice for vaccine development because of its safety profile and its generally strong and two-pronged immune reaction - both important characteristics for lasting immunity. But because adenoviruses also cause the common cold, many people have existing antibodies against the virus, and would clear away any adenovirus-based vaccine before it has a chance to act. New research from Dr. Snook's laboratory shows that introducing a component of a less common adenovirus strain can make the vaccine more effective and less likely to be cleared by existing antibodies.

Rather than using a new carrier or broker, which would have triggered a restart in the clinical trials process, the investigators tweaked the existing vaccine based on commonly used serotype called adenovirus 5, or Ad5. To this, they added the spike protein of a rare adenovirus serotype Ad35 to create a hybrid vaccine Ad5.F35.

Dr. Snook and colleagues first showed that the Ad5.F35 cancer vaccine produced a comparable immune response to the original Ad5 vaccine in animal models of colorectal cancer. Similar to the Ad5, the vaccine with the F35 component added showed no toxicity in non-tumor tissue.

The researchers also showed that the Ad5.F35 vaccine was resistant to clearance by antibodies produced by mice exposed to Ad5. They also showed that the sera of colorectal cancer patients with Ad5 antibodies was not able to neutralize the vaccine.

"We speculate that based on these data, more than 90% of patients should produce a clinically meaningful immune response to the new version of the vaccine, whereas we would only expect about 50% to respond to the first version," says Dr. Snook.

The phase II clinical trial aims to enroll 100 patients with gastric, pancreatic, esophageal or colon cancers who have been treated with first-line therapy and are in remission. Eligible patients will have undergone standard first-line therapy, usually surgery and chemo or radiation therapy, with no evidence of disease.

"This cancer vaccine is really designed to help the body keep the cancer from coming back," says Babar Bashir, MD, assistance professor of medical oncology at Jefferson and researcher with the SKCC, who is the clinical leader on the trial. "It's not powered to remove large tumor burden. But recurrence is a major problem for each of these cancers, and being able to reduce the chance of recurrence can translate to major improvements in a patient's longevity."

"This work is the latest advance in what is a larger effort at the Sidney Kimmel Cancer Center at Jefferson to develop effective cancer vaccines. We are so proud of the laboratory and clinical teams, who ensure that discoveries are fast-tracked to the clinic, and provide our patients in Philadelphia access to the most advanced form of cancer care," said Karen E. Knudsen, PhD, EVP of Oncology Services at Jefferson Health and Enterprise Director of the Sidney Kimmel Cancer Center.

The ?ourishing of topological photonics in the last decade was achieved mainly due to developments in linear topological photonic structures. However, when nonlinearity is introduced, many intriguing questions arise. For example, are there universal ?ngerprints of the underlying topology when modes are coupled by nonlinearity, and what can happen to topological invariants during nonlinear propagation? To explore these questions, A new paper published in Light Science & Application, a team of scientists, led by Professor Zhigang Chen from the MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China and co-workers have experimentally demonstrated nonlinearity-induced coupling of light into topologically protected edge states using a photonic platform and developed a general theoretical framework for interpreting the mode-coupling dynamics in nonlinear topological systems.

The experiment results show the nonlinearity-induced mode-coupling between bulk and topological edge states, as they stated in the text:

"In the ?rst case, the topological defect is located at the SSH lattice edge (Fig. 1, left panels). When a narrow stripe beam is launched straight into the edge waveguide under linear conditions, it evolves into a topological edge state (Fig. 1(a2)). Such an edge state, with a characteristic amplitude and phase populating only the odd-numbered waveguides counting from the edge, is topologically protected by the chiral symmetry of the SSH lattice, as previously observed in the 1D photonic superlattice. On the other hand, when the excitation is shifted away from the edge with a tilted broad beam to pump the defect, we observe that the beam does not couple into the edge channel under linear conditions (Fig. 1b1). However, when the beam experiences a self-focusing nonlinearity, a signi?cant portion of the beam is coupled into the edge channel (Fig. 1b2), indicating that the nonlinearity somehow enables the energy to ?ow from the bulk modes into the topological edge mode of the SSH lattice."

They have developed a general theoretical framework to explained the nonlinear process of a certain system:

"However, we observe that the interplay of nonlinearity and topology can couple light into the topological edge state of the linear system, which is inadmissible for entirely linear dynamics (e.g., see Fig. 1 (b2) and Fig. 2d-f). When this happens, we can identify

the nonlinear edge mode φ_(NL,edge), which inherits the pro?le of the linear edge mode φ_(L,edge) in the edge channel and is quanti?ed by F_edge (z)?0.98 after the nonlinear coupling has occurred, although it lacks the amplitude in the third waveguide. Thus, for a high nonlinearity, the eigenvalue of φ_(NL,edge) moves outside the gap (see Fig. 2c), and the edge mode is dominated by nonlinearity but has some features inherited from the linear topological edge mode; for a low nonlinearity, its eigenvalue stays inside the gap, so it is dominated mainly by the topology."

[Points]

- Wide personality traits and attributes such as extraversion and IQ were predicted from Twitter information

- Network and linguistic information from Twitter usage predicts social personality and mental health

- The findings could lead to new technologies for mental health diagnostics and personalized nudges

[Abstract]

Principle Investigator HARUNO Masahiko and Dr. MORI Kazuma at the Center for Information and Neural Networks (CiNet), the National Institute of Information and Communications Technology (NICT, President: TOKUDA Hideyuki, Ph.D.), report the use of machine learning to analyze behavior on Twitter and predict a wide range of personality traits and attributes such as intelligence and extraversion. Specifically, the study uses component-wise gradient boosting to demonstrate that network features, such as the number of Tweets and the number of likes, and word usage on Twitter are predictive of social (e.g., extraversion) and mental health (e.g., anxiety) personalities, respectively. This approach may provide a new way for mental health diagnostics and personalized nudges.

The new study was published in Journal of Personality online on Thursday, August 20, 2020.

[Background]

Social media services (SNS) have quickly become universal tools for communication. Previous research has shown that information about Facebook and Twitter use can reveal basic and course personality traits based on the Big 5. However, which types of SNS information can be used to pinpoint specific personality traits and attributes are unknown. There is growing interest about what personality traits and attributes can be predicted by analyzing SNS information and how accurately that information reflects the user.

[Achievements]

The study by Dr. MORI and Principle Investigator HARUNO discovered that a wide range of personality traits and attributes can be predicted by analyzing four different types of users' behaviors on Twitter (i.e., network features, time, word statistics, and word usage).

A statistical analysis found significant correlations between measured personality and attribute scores and predicted ones, with correlation coefficients around 0.25. This value is not sufficient for determining an individual's personality traits precisely, but with a large enough population sample, this technology can provide informative results.

The study collected social media information from 239 participants (156 men, 83 women; average age 22.4 years old) who also took personality tests that measured 24 personality traits and attributes (52 subscales). Of the 52 subscales, the Twitter information could be reliably used to predict 23 of them. Figure 2A showcases a positive correlation (correlation coefficient = 0.44) between the measured and predicted Big 5 extraversion scores based on a 10-fold cross-validation procedure done 10 times (Bonferroni corrected p value of 0.05/52).

The analysis revealed that several social personality traits such as extraversion, empathy and autism could be predicted from network features (Figure 2B). Other personality traits such as socioeconomic status, smoking/drinking, and even depression or schizophrenia were predictable from the language usage features (Figure 2C and D). Prediction from time was more difficult to correlate with measured personalities, but did show a significant correlation with intelligence and social value orientation.

[Future Prospects]

We are expanding the analysis to thousands of subjects. The method described in this study could be used to for mental health diagnostics and personalized nudges to act on people's behaviors. It will also give insight on the neural mechanisms underlying individual differences in personality traits.

BALTIMORE, MD (August 24, 2020) - A new study from the University of Maryland School of Medicine (UMSOM) has found wide variations throughout the United States in the way hospitals ensure that premature or low birth weight infants can breathe safely in a car seat before discharging them. The study, published this month in the journal Pediatrics, found that the same infant who passes a screening in one hospital's newborn nursery (NBN) may fail in similar facilities at another hospital's nursery. The authors concluded that "further guidance on screening practices and failure criteria is needed to inform future practice and policy" in order to better protect these vulnerable newborns.

"Proper placement of an infant in their car seat can be a challenge, but it's important to get it right. Research has shown that 63 percent of infant sleep-related deaths that occur in sitting devices are in car seats," said the study lead author, Natalie L. Davis, MD, MMSc, Associate Professor of Pediatrics at UMSOM and a Neonatologist at the University of Maryland Children's Hospital.

The American Academy of Pediatrics (AAP) recommends a car seat tolerance screen (CSTS) for all premature newborns in the U.S. in order to identify any heart or breathing risks that could make use of a car seat unsafe in these babies whose lungs are not fully developed.

"The infants are placed in a car seat with a breathing and heart rate monitor for an hour-and-a-half to two hours to see if they are breathing effectively," Dr. Davis said. "The problem is that the AAP recommendations do not have specific guidelines on what to test for and how to test, and do not provide much guidance on what doctors should do if infants fail these tests," said Dr. Davis.

Hospitalized newborns are placed flat on their backs as part of national "Back-to-Sleep" measures to prevent sudden infant death syndrome (SIDS). "In the hospital, we use monitors on at-risk premature babies, and we do not send them home until they have established normal vital signs in their crib," said Dr. Davis. When at-risk infants are placed in a car seat for the ride home from the hospital, however, the semi-upright sitting position can pose breathing obstacles that may not be obvious in the flat-back position.

To gain a snapshot of CSTS practices today, the researchers conducted a survey across 35 states using a network of hospitals that participate in an outcomes research network. Of the 84 newborn nurseries surveyed, 90.5 percent reported performing a pre-discharge CSTS. Dr. Davis and her colleagues found, however, that newborn nurseries varied in how they selected newborns to be screened and what parameters they used to identify failure on a test. They also had inconsistent practices in how they dealt with a screening failure in terms of recommendations for parents to use special infant car beds instead of car seats and in making referrals to specialists for follow-up monitoring.

Most NBNs surveyed said they did repeat a CSTS after an initial failure, but the timing ranged from an immediate retest, to a minimum seven-day observation before retesting.

In a previous study published earlier this year in the journal Academic Pediatrics, Dr. Davis and her colleagues also found similar inconsistencies in the use of CSTS among infants discharged from neonatal intensive care units in hospitals throughout the country.

Dr. Davis said the findings from both studies highlight the need for more specific recommendations from the AAP to define failure criteria on these tests and recommended steps for follow-up if an infant fails. While she acknowledged that limited data have made it difficult for the AAP to establish evidence-based guidelines, having nationally consistent recommendations could help improve the collection of data and lead to refinement of the advice if needed.

"If we are all doing something similar," she said, "then we can consistently see if we are actually catching the babies who are at risk and take the appropriate steps we need to modify from there."

Two areas that can be improved immediately:

1. Parents and caregivers can be better educated on the proper placement and fit of an infant in the car seat through the use of child passenger safety technicians at the hospital.

2. Newborn nurseries should arrange for appropriate post-discharge follow-up, particularly if an infant is sent home in a car bed. Parents will need to know when it is safe to transition their baby to an upright infant car seat.

"This research clearly establishes a need for national standards to ensure that hospitals are providing consistent care to neonates," said E. Albert Reece, MD, PhD, MBA, a specialist in maternal-fetal medicine, who is Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. "It also points to the need for better data to help inform our medical societies when they make these public health recommendations."

Changes in the water cycle have important impacts on ecosystems and human activities. In the context of the current and expected temperature rise due to global warming, it is extremely important to understand the origin and extent of these changes.

A recent study published in the journal Nature Geosciences analyses the changes in global average water availability on land - defined by the difference between precipitation and evapotranspiration - eliminating any remaining uncertainties about human responsibility for variations in the hydrological cycle observed during the dry-season throughout the last century.

The research, realized with the contribution of the CMCC Foundation - Euro-Mediterranean Center on Climate Change, is entitled "Observed changes in dry-season water availability attributed to human-induced climate change" and is made up of two phases.

First, authors used land surface models and statistical models guided by observations to produce and compare global maps of water availability from 1902 to 2014, a period during which our planet experienced a global warming effect of approximately 1°C. The analysis focused on the difference in average water availability of the driest month between the 1902-1950 and the 1985-2014 period.

Results show a reduction in average water availability at a global level during the last century, with some regions experiencing increased and some decreased water availability. 57-59% of land areas, predominantly in extratropical latitudes, experienced a decrease in dry-season water availability. These areas include Europe, western North America, northern Asia, southern South America, Australia, northern Andes and eastern Africa. On the other hand, humidity during the dry season has increased in 41-43% of land areas, including inland China, southeastern Asia and the Sahel.

Moreover, the study shows that the intensification of the dry season is generally a consequence of increasing evapotranspiration rather than decreasing precipitation.

The second step was to understand the causes of this change, in order to understand if and in what terms these effects are connected to human-induced climate change rather than natural variability.

"Through a multi-model analysis, we have compared in different sets of experiments the spatial distribution of water availability in three different configurations: the world in 1850 (pre-industrial), the world as we observe it today (which is influenced by both natural and human-induced variability) and the world we would observe today if the climate had been influenced only by natural variability", explains Daniele Peano, researcher within the Climate Simulations and Predictions division at the CMCC Foundation, and co-author of the study. "With or without considering human activity, simulations bring us into a completely different early twenty-first-century world. Instead, the pre-industrial world is not so different from what we would have had today without anthropogenic influence on the climate system. Thus, we excluded the impact of natural variability, establishing human influence as the only explanation for the changes in water availability on land from the pre-industrial era to date."

This is the first time a scientific study demonstrates a correlation between human-induced climate change and changes in the water availability during the dry seasons: in previous assessments, a high level of uncertainty remained, due to the inability to exclude the influence of natural climate variability.

The valleys of two-dimensional transition metal dichalcogenides (TMDCs) offer a new degree of freedom for information processing and have attracted tremendous interest for their possible applications in valleytronics. To develop valleytronics devices based on TMDCs, effective approaches to separate valleys in the near or far field are indispensable. In recent researches, kinds of nanostructures are proposed to separate valleys and much progress has been made.

In a new paper published in Light Science & Application, a team of scientists, led by Professor Jian Zi, Professor Lei Shi from Fudan University and Professor Tian Jiang from National University of Defense Technology, and co-workers demonstrate that two-dimensional all-dielectric PhC slabs without in-plane inversion symmetry can be used to efficiently separate valley exciton emission of a WS2 monolayer in the far field at room temperature. Based on circularly polarized delocalized Bloch modes, the valley exciton emission is routed with high directionality and high degree of valley polarization. The delocalized Bloch modes not only play a critical role in separating and enhancing directional valley exciton emission, but also lead to spatial coherence properties of the emission field, which are neglected to be discussed in the past studies. This property of PhC slab extends the coherence control on PL of WS2 monolayer from temporal coherence to spatial coherence.

Due to the powerful ability of manipulating light, PhCs have been widely applied in various researches, such as PhC lasers and spontaneous emission control of TMDCs. However, to date, there are no reports of effective valley separation in TMDCs by using PhCs. The scientists introduce their method:

"For the radiative modes of PhC slabs, their polarization states in the far field are strictly defined. However, owing to high rotation symmetry, the polarization field is nearly linear in most PhC slabs. In our recent research, we reported that by breaking in-plane inversion symmetry of PhC slabs, circularly polarized states would emerge in photonic bands. This lays the foundation for us to control valley exciton emission via PhC slabs."

"Especially, the PhCs' Bloch modes are delocalized, which would lead to the coherence properties of TMDCs' emission field. We performed the Young's double-slit experiment to directly observe the interference fringes."

"Our method could be extended to manipulate valley exciton emission of other TMDCs monolayers. The ability of this PhC slabs to transport valley information from the near field to the far field would help to develop photonic devices based on valleytronics." They added.

Light-field imaging can detect both spatial and angular information of light rays. The angular information offers peculiar capabilities over conventional imaging, such as viewpoint shifting, post-capture refocusing, depth sensing, depth-of-field extension, etc. The concept of plenoptic cameras by adding a pinhole array or microlens array was proposed more than a century ago. Nowadays, microlens array based plenoptic cameras are commonly used for light-field imaging, such as the commercially available products, Lytro and Raytrix. However, these devices confront a trade-off between the spatial and angular resolutions; the spatial resolution is in general tens to hundreds times smaller than the number of pixels used.

In a new paper published in Light Science & Application, a team of scientists from College of Physics and Optoelectronic Engineering, Shenzhen University, China and Institut für Technische Optik, Universität Stuttgart, German have developed "a novel modality for computational light-field imaging by using a diffuser as an encoder, without needing any lens. Through the diffuser, each sub-beam directionally emitted by a point source in the detectable field-of-view forms a distinguishable sub-image that covers a specific region on the sensor. These sub-images are combined into a unique pseudorandom pattern corresponding to the response of the system to the point source. Consequently, the system has the capability of encoding a light field incident onto the diffuser. We establish a diffuser-encoding light-field transmission model to characterize the mapping of four-dimensional light fields to two-dimensional images, where a pixel collects and integrates contributions from different sub-beams. With the aid of the optical properties of the diffuser encoding, the light-field transmission matrix can be flexibly calibrated through a point source generated pattern. As a result, light fields are computationally reconstructed with adjustable spatio-angular resolutions, avoiding the resolution limitation of the sensor."

They constructed an experimental system using a diffuser and a sensor. The system was demonstrated for distributed object points and area objects, which shows the object-dependent performance of the computational approach. The performance regarding the spatio-angular samplings and measured objects was further analyzed. After that, these scientists made a summary of their approach:

"The improvement of the proposed methodology over the previous work on diffuser-encoding light-field imaging mainly lies in two aspects. One is that our imaging modality is lensless and thus is compact and free of aberration; the other is that the system calibration and decoupling reconstruction become simple and flexible since only one pattern generated by a point source is required."

"Based on this single-shot lensless light-field imaging modality, light rays, viewpoints, and focal depths can be manipulated and the occlusion problem can be tackled to some extent. This allows to further investigate the intrinsic mechanism of the light-field propagation through the diffuser. It is also possible to transform the diffuser-encoding light-field representation into the Wigner phase space so that the diffraction effect introduced by the internal tiny structure of the diffuser can be taken into account and lensless light-field microscopy through diffuser encoding may be developed." the scientists forecast.

Non-orthogonal multiple access (NOMA) and millimeter-wave (mmWave) are two crucial techniques of 5G to meet the explosive capacity demands. On the other hand, UAVs deployed as aerial base stations are potential to provide ubiquitous coverage and satisfy users' multifarious requirements due to their flexibility and mobility. Nevertheless, the finite onboard energy is a fundamental limit of UAVs, which can deter the performance of UAV communication networks. Therefore, the researchers Xiaowei Pang and Nan Zhao from Dalian University of Technology, Jie Tang and Xiuyin Zhang from South China University of Technology, and Yi Qian from University of Nebraska-Lincoln have focused on designing energy-efficient transmission schemes for mmWave-enabled NOMA-UAV networks. The network model is illustrated in Fig. 1, where the UAV equipped with multiple antennas serves K single-antenna ground users who are grouped into M clusters in the downlink.

"Although a large amount of research has contributed to integrating mmWave or NOMA with UAV communications, respectively," wrote the five researchers, "few of them investigated on mmWave-enabled NOMA-UAV networks."

In mmWave networks, the number of supported users conventionally cannot be larger than the number of RF chains at the same time-frequency resources. To break this fundamental limit, the users are grouped into multiple clusters according to their channel correlations, and NOMA is employed in each cluster to serve users simultaneously. To achieve a good balance between system complexity and performance, a hybrid precoding architecture is adopted to reduce the hardware cost and energy consumption. The authors aim to maximize the energy efficiency of mmWave-enabled NOMA-UAV networks by optimizing the UAV placement, hybrid precoding and power allocation. Due to the fact that the overall energy efficiency maximization problem is intractable, it is divided into several sub-problems. First, they optimize the UAV placement considering the total channel strength of all UAV-served users. And then, the hybrid precoding schemes with user clustering are proposed to better reap the multi-antenna gain. The last step is to optimize the power allocation among users to maximize the energy efficiency with users' quality of service requirements and an efficient algorithm is presented to solve the problem iteratively.

It's worth mentioning that three hybrid precoding schemes are introduced in the network, all of which perform user clustering and design the analog and digital precodings to improve the multiplexing gains and suppress the inter-user interference. Particularly, the major distinction among them is that they can achieve different performance of user fairness, spectrum efficiency and energy efficiency, which are further demonstrated by simulation results. The effectiveness of the proposed energy-efficient design is verified through numerical comparisons with other schemes without UAV placement optimization and without energy efficiency requirement. Moreover, numerical results also reveal the effects of the maximum UAV transmit power and the number of RF chains on the energy efficiency.

CHAMPAIGN, Ill. -- In the nanoworld, tiny particles such as proteins appear to dance as they transform and assemble to perform various tasks while suspended in a liquid. Recently developed methods have made it possible to watch and record these otherwise-elusive tiny motions, and researchers now take a step forward by developing a machine learning workflow to streamline the process.

The new study, led by Qian Chen, a professor of materials science and engineering at the University of Illinois, Urbana-Champaign, builds upon her past work with liquid-phase electron microscopy and is published in the journal ACS Central Science.

Being able to see - and record - the motions of nanoparticles is essential for understanding a variety of engineering challenges. Liquid-phase electron microscopy, which allows researchers to watch nanoparticles interact inside tiny aquariumlike sample containers, is useful for research in medicine, energy and environmental sustainability and in fabrication of metamaterials, to name a few. However, it is difficult to interpret the dataset, the researchers said. The video files produced are large, filled with temporal and spatial information, and are noisy due to background signals - in other words, they require a lot of tedious image processing and analysis.

"Developing a method even to see these particles was a huge challenge," Chen said. "Figuring out how to efficiently get the useful data pieces from a sea of outliers and noise has become the new challenge."

To confront this problem, the team developed a machine learning workflow that is based upon an artificial neural network that mimics, in part, the learning potency of the human brain. The program builds off of an existing neural network, known as U-Net, that does not require handcrafted features or predetermined input and has yielded significant breakthroughs in identifying irregular cellular features using other types of microscopy, the study reports.

"Our new program processed information for three types of nanoscale dynamics including motion, chemical reaction and self-assembly of nanoparticles," said lead author and graduate student Lehan Yao. "These represent the scenarios and challenges we have encountered in the analysis of liquid-phase electron microscopy videos."

The researchers collected measurements from approximately 300,000 pairs of interacting nanoparticles, the study reports.

Click here to see liquid-phase electron microscopy with combined machine learning in action.

As found in past studies by Chen's group, contrast continues to be a problem while imaging certain types of nanoparticles. In their experimental work, the team used particles made out of gold, which is easy to see with an electron microscope. However, particles with lower elemental or molecular weights like proteins, plastic polymers and other organic nanoparticles show very low contrast when viewed under an electron beam, Chen said.

"Biological applications, like the search for vaccines and drugs, underscore the urgency in our push to have our technique available for imaging biomolecules," she said. "There are critical nanoscale interactions between viruses and our immune systems, between the drugs and the immune system, and between the drug and the virus itself that must be understood. The fact that our new processing method allows us to extract information from samples as demonstrated here gets us ready for the next step of application and model systems."

The team has made the source code for the machine learning program used in this study publicly available through the supplemental information section of the new paper. "We feel that making the code available to other researchers can benefit the whole nanomaterials research community," Chen said.

According to the scientists, this plant is a source of valuable biologically active substances with cardioprotective, neuroprotective, anti-inflammatory, antitumor, and antiviral effects.

Researchers have proven heather to be effective herbal medicinal raw material. This small relict, evergreen shrub is a widespread plant in Europe and has long been used as a medicine for the treatment of rheumatism, arthritis, as well as an antiseptic, choleretic, wound healing, expectorant. A wide range of medicinal properties of heather is determined by the diversity and high content of biologically active substances in the plant, primarily phenolic compounds, which perform many different functions, for example, they are involved in photosynthesis and plant breathing process.

Heather is not included in the list of medicinal products. However, according to the scientists, this plant is a source of valuable biologically active substances with cardioprotective, neuroprotective, anti-inflammatory, antitumor, and antiviral effects. To prove this, the staff and students of the Institute of Living Systems have been collecting common heather from May to October 2019 at four stages (beginning of vegetation, budding, flowering, and fruiting) in the Pig Swamp on the Curonian Spit. Scientists have determined the content of biologically active compounds in the leaves, stems, roots, rhizomes, flowers, and seeds, as well as the antioxidant and antibacterial activity of the extracts against the bacteria of E. coli and hay bacillus.

Lyubov Skrypnik, Ph.D. in Biology, Associate Professor at the Institute of Living Systems told us:

"The phytochemical composition of heather is well studied. However, there was no research on the seasonal dynamics of the quantitative content of flavonoids, tannins, anthocyanins, proanthocyanins, hydroxycinnamic acids. In addition, earlier most of the studies were devoted to the study of the aboveground part of the heather, but in our work, we proved that phenolic compounds are actively accumulating in underground organs - the roots and rhizomes of the plant. Typically, heather is harvested for medicinal purposes during the flowering stage. But in the course of the study, we found that the maximum amount of flavonoids, which are of the greatest medicinal value, accumulates in all organs of the heather during the budding phase. This leads to a recommendation for harvesting heather plants just before flowering. Additionally, it was found that the budding stage is the only stage at which the antibacterial activity of the extracts of all the studied parts of the plant was found simultaneously, and the leaves and stems showed an antibacterial effect against bacteria of E. coli and hay bacillus".

Researchers from the Universities of Turku and Helsinki in Finland have been looking into literature about wind farm impacts on bats in several countries around the Baltic Sea (Estonia, Finland, Latvia, Lithuania, Russia and Sweden) and in the rest of Europe. They published a review on the topic.

The results are quite straightforward: impacts of wind farms on bats in the Baltic Sea region have barely been investigated.

"Only a handful of reports and studies are available, and they are rarely in English. The main reasons for this lack of data are probably the small numbers of turbines in the region and the shortage of information on bats themselves," says Simon Gaultier from the University of Turku, one of the authors of the review.

The authors also think it is important to not rely entirely on knowledge from the rest of Europe to study bats and wind farms in the Baltic Sea region.

"The climate and environmental conditions for bats are different, influencing the biology and ecology of these species, including the way they are affected by wind farms."

There are also concerns about survey methods and quality, especially during the environmental impact assessment of wind farm projects. It seems that current methods are not adapted to predict the actual presence of bats on the future wind farms, let alone the impacts they are facing, such as collision risks.

Turbines are more and more numerous in the Baltic Sea region, a region that plays an important role for European bats: it is crossed by numerous migrating bats during spring and autumn, but is also the home of other local resident bat species such as the Northern bat (Eptesicus nilssonii).

"At some point, concerns about bat conservation will appear. Bat numbers are not increasing, contrary to wind turbines. We need to anticipate and avoid this problem. However, in order to do this, we first need more information on bats."

Following this need, Gaultier started collecting new data during this summer. Using ultrasound recorders located around wind farms, Gaultier and his colleagues are looking for the possible effects turbines are having on the presence and activity of bats. Other studies have reported bats being attracted by wind turbines, others being repelled.

"We need to monitor bats for several years to see what is going on in Finland, but we should get a first glimpse by the end of this year," says Gaultier.

"In the end, we want our work to be useful for both wind power planning and bat preservation by defining high-risk areas where wind turbines should not be built or designing supplementary measures to reduce the impact of current and future wind farms," he adds.

Big mammals such as elephants, rhinos and primates are at highest risk of extinction in the national parks and nature reserves of the world's poorest countries, a new global review has found.

The review, which looked at 81 studies carried out between 1980 and 2020, found that illegal hunting was causing worrying declines in the big mammal populations of protected areas across the globe, and particularly in poorer countries.

In the four continents included in the study, 294 different mammal species were discovered to have been illegally hunted in the national parks created to protect them.

The threat species face in poorer countries may be down to a boom in bushmeat trade and a lack of resources for conservation.

In order to protect species, governments and policy makers need to focus on tackling human poverty, the researchers urge.

Lead author of the study, Dr Alfan Rija, of Tanzania's Sokoine University of Agriculture who conducted the review while a PhD student at the University of York, said: "We have known for several years that illegal hunting reduces mammal populations, but our review reveals that this is happening even inside protected areas and particularly affects larger mammals (those with a body mass of over 100kg) in the poorest countries. In poorer countries such as my home of Tanzania, bushmeat is a valuable source of income and protein in some areas and there is also less resources available to invest in the security and policing of national parks.

"The threat from illegal hunting is particularly dangerous to large mammals because they have slow growth rates and so over-hunting is likely to cause population decline.

"Aside from concerns about the future of many of these species being in peril, the loss of mammals due to illegal hunting pressure has been related to substantial loss of important functional characteristics in an ecosystem. They support many ecological interactions - such as seed dispersal and regeneration - and their decline threatens wider biodiversity."

The study found that in general across the globe, stricter protected areas showed lower rates of large mammal population decline. However, this was not the case in Asia, where stricter national parks had higher rates of illegal hunting and species decline.

Senior author of the study, Dr Colin Beale from the Department of Biology at the University of York, said: "Our research adds to a growing number of studies that suggest Asia is currently a particular focus for the illegal trade of wildlife body parts. Despite strict laws, illegal hunters may be forced to enter protected areas where most sought-after species such as snow leopard, tiger, pangolin, orangutans and sun bears still remain.

"Improving the effectiveness of Asian protected areas will be important to strengthen biodiversity conservation across continental Asia, and is likely to need a range of measures including ensuing effective law enforcement as well as work with communities in and around valuable wildlife areas."

A new study has revealed how remora suckerfish detach themselves from the surfaces they've clung to - and how the mechanism could provide inspiration for future reversible underwater adhesion devices.

The research, by an international, multidisciplinary team working across robotics, comparative biology, and electrical engineering, investigated the detachment mechanism of the remora's suction disc, and experimented with how it could be applied in underwater robots.

The team's findings are published today in the IOP Publishing journal Bioinspiration and Biomimetics.

Lead author Professor Li Wen, from Beihang University, Beijing, said: "Marine organisms mainly use two methods of adhesion in submerged environments: chemical adhesion and suction adhesion. Remora's hitchhiking behaviour uses suction adhesion and requires these fishes to be capable of both attaching and detaching regularly, but their detachment remains poorly understood.

"Understanding detachment is essential in studying biological adhesive systems. It is also becoming increasingly important in many engineering applications such as surface peeling (surface painting, coating and transfer printing). We explored how a remora detaches to expand the understanding of this biological system, and to see how it could be applied to artificial adhesion mechanisms."

To do this, the research team studied the detachment kinematics and associated morphology of live remoras.

Co-author Dr. Dylan Wainwright, from the Museum of Comparative Zoology, Harvard University, said: "the micro CT scanning results show that lip muscles are distributed ventrally around the outer edge of the disc pad. Contraction of the anterior-most lip muscles peels the disc lip away from the surface, reducing the pressure differential."

They then separated the detachment process into three stages and tested the effects of lamellae motion, disc flexibility, and disc lip motion on adhesive performance during detachment.

Co-author Professor Yufeng Chen, from the Massachusetts Institute of Technology, USA, said: "Using what we learned from observing the live remoras, we developed a biomimetic flexible adhesive disc with controllable motion of both the disc lip and the lamellae with spinules.

"To test if the disc worked in the same way as the real thing, we designed and built a biomimetic remora robot with a rigid body. It is composed of four parts: a 3D printed fish-like body, the biomimetic suction disc, a control unit and a jet propulsion component.

The first author Siqi Wang, from Beihang University said: "The robot showed similar detachment motions to its biological counterpart, mimicking the three-stage detachment. The entire detachment process took about 200 ms, which is even faster than the detachment of the live remoras (240 ms) we recorded."

"Using two biomimetic suction discs, the robot has both 'hitching' and 'pick and place' capabilities. This scalable ability of the biomimetic suction disc gives the current underwater robot broad applications including long-term underwater transportation, archaeology, search and rescue, and biological observation.

Professor Wen said: "We hope this study will provide an important step towards the practical realisation of the remora's suction mechanism for real-world applications."