Tech

The Raspberry Pi Virtual Reality system (PiVR) is a versatile tool for presenting virtual reality environments to small, freely moving animals (such as flies and fish larvae), according to a study published July 14, 2020 in the open-access journal PLOS Biology by David Tadres and Matthieu Louis of the University of California, Santa Barbara. The use of PiVR, together with techniques like optogenetics, will facilitate the mapping and characterization of neural circuits involved in behavior.

PiVR consists of a behavioral arena, a camera, a Raspberry Pi microcomputer, an LED controller, and a touchscreen. This system can implement a feedback loop between real-time behavioral tracking and delivery of a stimulus. PiVR is a versatile, customizable system that costs less than $500, takes less than six hours to build (using a 3D printer), and was designed to be accessible to a wide range of neuroscience researchers.

In the new study, Tadres and Louis used their PiVR system to present virtual realities to small, freely moving animals during optogenetic experiments. Optogenetics is a technique that enables researchers to use light to control the activity of neurons in living animals, allowing them to examine causal relationships between the activity of genetically-labeled neurons and specific behaviors.

As a proof-of-concept, Tadres and Louis used PiVR to study sensory navigation in response to gradients of chemicals and light in a range of animals. They showed how fruit fly larvae change their movements in response to real and virtual odor gradients. They then demonstrated how adult flies adapt their speed of movement to avoid locations associated with bitter tastes evoked by optogenetic activation of their bitter-sensing neurons. In addition, they showed that zebrafish larvae modify their turning maneuvers in response to changes in the intensity of light mimicking spatial gradients. According to the authors, PiVR represents a low-barrier technology that should empower many labs to characterize animal behavior and study the functions of neural circuits.

"More than ever," the authors note, "neuroscience is technology-driven. In recent years, we have witnessed a boom in the use of closed-loop tracking and optogenetics to create virtual sensory realities. Integrating new interdisciplinary methodology in the lab can be daunting. With PiVR, our goal has been to make virtual reality paradigms accessible to everyone, from professional scientists to high-school students. PiVR should help democratize cutting-edge technology to study behavior and brain functions."

The androgen receptor is the primary driver of the initiation and growth of prostate cancer, the second-leading cause of death in men. Looking to have a better understanding of how the androgen receptor works in cancer, researchers at Baylor College of Medicine conducted comprehensive studies of the 3-D structure of the receptor.

The findings unveiled the structure of a site on the receptor that seems to be at the heart of its action, called the N-terminal domain, where it interacts with activity-enhancing coactivators that together regulate gene expression that drives prostate cancer. The study, published in the journal Molecular Cell, offers new insights for the design of future treatments for this devastating condition.

The androgen receptor

"The androgen receptor binds to and mediates the effects of the androgenic hormone testosterone. The receptor is found in several tissues of both males and females, including skeletal muscle, heart and the nervous and the reproductive systems," said co-first author Dr. Ping Yi, assistant professor of molecular and cellular biology at Baylor. "In males, the androgen receptor contributes to the development of sexual characteristics, and in both males and females it also regulates hair growth and sex drive."

Previous studies had shown that when the androgen receptor binds to testosterone, the resulting molecular complex travels to the cell nucleus where it interacts with DNA, turning genes on or off as necessary to regulate development and growth. To carry on its activity, the androgen receptor also binds to coactivators and other molecules that promote its gene-regulatory function. However, how all these molecules are put together in a functional complex with the androgen receptor was not known.

"The androgen receptor drives prostate cancer," said co-corresponding author Dr. Bert O'Malley, chancellor and former long-time chair of the Department of Molecular and Cellular biology at Baylor. "To treat this cancer effectively, we need to better understand how the androgen receptor works. In this study, we reveal for the first time the complete 3-D structure of the active, full-length androgen receptor-coactivator complex as it interacts with DNA."

Cryo-EM reveals new components of androgen receptor structure and function

Before this study, researchers only had a partial idea of the 3-D structure of the androgen receptor. They were missing a part called the N-terminal domain, which biochemical evidence suggested might be crucial for its activity. Resolving the complete structure of the receptor would help understand why the N-terminal domain is key to the receptor's activity.

"Cryo-electron microscopy let us see what the N-terminal domain of the androgen receptor looks like, how the protein is organized and how this and other individual domains contribute to the coactivated protein and its function," said Yi, a member of Baylor's Dan L Duncan Comprehensive Cancer Center.

The researchers discovered that the N-terminal domain at the beginning of the androgen receptor is where the coactivators bind, activating the complex that drives prostate cancer. This finding was in marked contrast with what the same researchers had discovered for the estrogen receptor, which is a major driver of breast cancer.

The androgen and the estrogen receptors belong to the same family of steroid nuclear receptors and share similar 3-D structures. However, despite having general structural similarities, in the estrogen receptor the coactivators bind not to the N-terminal domain at the beginning of the molecule, but to the C-terminal domain at the end of the molecule. This finding has important implications generating drugs for cancer treatment.

Therapeutic implications

"The androgen receptor drug inhibitors that are currently available for prostate cancer treatment bind to the C-terminal domain, which we found is not the main interactive site of the androgen receptor," O'Malley said. "Our work strongly supports further studies to determine the effect that drugs directed at the androgen receptor's N-terminal domain have on prostate cancer growth."

"Our work provides a starting point to understand what is happening to the androgen receptor molecular machine in prostate cancer," said co-corresponding author Dr. Zhao Wang, assistant professor in the Verna and Marrs McLean Department of Biochemistry and Molecular Biology. "Our findings also generate a broader therapeutic space for the treatment of not only prostate cancer but also related diseases, as well as new information on basic mechanisms of regulation of gene expression."

Farmland bird species are declining over most of Europe. Birds breeding on the ground, are particularly vulnerable because they are exposed to mechanical operations, like ploughing and sowing, which take place in spring and often accidentally destroy nests.

Locating nests on the ground is challenging for the human eye, and highly time-consuming

Researchers flew a drone carrying a thermal camera over agricultural fields to record images. These were then fed to an artificial intelligence algorithm capable of accurately identifying nests, a first step to aid their protection. Researchers tested the system in Southern Finland near University of Helsinki's Lammi Biological Station, using wild nests with eggs of the Lapwing Vanellus vanellus.

"We have been involved in conservation of ground-nesting farmland birds for years, and realized how difficult it is to locate nests on the ground. At least at high latitudes, the temperature of these nests is typically higher than that of the surrounding environment. Hence, we thought that thermal cameras could assist. A small pilot study indicated that thermal vision is hampered by vegetation and objects on the ground. Therefore to make this an efficient system, we thought that the camera could be flown using a drone, and artificial intelligence could help to analyse the resulting thermal images. We show that this works. However, the system performed best under cloudy and cold conditions, and on even grounds," says Andrea Santangeli, an Academy of Finland fellow at the Finnish Museum of Natural History Luomus, University of Helsinki.

Drone technology becoming rapidly popular in conservation

It is possible to map in near real-time the spread of diseases on crops in agricultural areas using drones with various sensors. The latter is an integral part of precision agriculture, a new way of crop production that makes large use of drone technology to monitor crops and maximize production efficiency.

Studies like this one can help pave the way to integrate bird nest detection within the drone borne sensors used in precision agriculture, and automate a system for saving those nests.

"The conservation community must be ready to embrace technology and work across disciplines and sectors in order to seek efficient solutions. This is already happening, with drone technology becoming rapidly popular in conservation. A next and most challenging step will be to test our system in different environments and with different species. Our auspice is that this system will be, one day, fully integrated into agricultural practices, so that detecting and saving nests from mechanical destruction will become a fully automated part of food production," says Andrea Santangeli.

The catastrophic effects of global environmental degradation, health deterioration and diminishing energy resources are demanding remedy measures aimed at environmental conservation, health interventions and harnessing of the abundant and renewable energy resources. Consequently, sensors and renewable energy harnessing systems have emerged as worthwhile solutions to the existent challenges. However, conventional sensors and renewable energy harnessing systems have presented diminished efficiency and performance to be improved. Therefore, current research trends are focusing on improving the efficiency and performance of these systems.

For centuries, nature has availed an unlimited cache of evolved biological species with improved energy harnessing capabilities and heightened responses to external stimuli, including temperature, pH, humidity and chemical molecules. Specifically, butterfly wings have gained research and aesthetic popularity for their vivid coloring, architypes of unique micro/nanostructures, sensitivity and effective responses to stimuli. While insect enthusiasts marvel at the beautiful wing coloration and patterning, researchers have determined that the vivid coloration and wing properties result from the structures and pigments found in the wing scales. The huge variety of beautifully colored wings has led researchers to classify the various unique wing scale architectures. Equally, researchers have made attempts to mimic the wing properties in fabrication of various manmade functional materials and systems, such as sensors and energy harnessing applications.

In the overview published in National Science Review, researchers in the State Key Laboratory of Metal Matrix Composites at Shanghai Jiao Tong University, Shanghai, China present the recent research progress in sensor and energy applications inspired by butterfly wings. In their review, Zhang W. and co-workers highlight the genesis of wing scale development and the subsequent formation of wing scale architectures. They describe the general appearance of the wing scale architectures as having three distinct regions namely, the highly convoluted upper lamina, flat and featureless lower lamina and pillar-like connection of the two layers called trabeculae. In addition, the authors discuss the most recent wing structure classification based on variations in specialized regions of the architectures. These wing scale architecture variations influence wing coloration among other properties, including porosity, surface area and responses to stimuli.

Recently, researchers have worked on a variety of sensor and energy systems with the aim of mimicking the properties of natural species into manmade functional systems. This published review has focused on the progress achieved in recent research towards the fabrication of sensor and energy systems inspired by butterfly wings. By employing the different properties of butterfly wings, featured researches have successfully fabricated thermal, medical and vapor sensors, anti-counterfeit security devices, photocatalysts, photovoltaic systems, triboelectric nanogenerators and energy storage systems. Comparatively, these featured systems have demonstrated competitive efficiency and performance to similar systems inspired by other natural species.

Unfortunately, more research is still necessary to achieve optimal replication of natural properties onto manmade functional systems. As a result, authors suggest that the application scope should extend to photothermal imaging and therapy in cancer treatment and management. The good performance recorded by medical sensors for health monitoring and photothermal capabilities of butterfly wing inspired materials will generate sufficient mechanism for the detection, imaging, therapy and monitoring of terminal diseases. Similarly, photothermal materials inspired by butterfly wings can gain interest in the emerging stealth technologies research for modern-day warfare and scientific research technologies, such as rockets. Lastly, butterfly wings have exhibited numerous and diverse properties that enable them effectively respond to external stimuli. Research should envision tapping onto these characteristics in fabrication of functional systems with multiple responses and high efficiencies. This should be a real break-through in attaining next generation applications that optimize the properties of natural species and meet the global energy shortages, environmental degradation and deteriorating health conditions.

Terahertz radiation, or T-rays, has barely been exploited compared to most of the rest of the electromagnetic spectrum. Yet T-rays potentially have applications in next-generation wireless communications (6G/7G), security systems, biomedicine, and even art history. A new device for controlling T-rays using a specially designed 'metasurface' with properties not found in nature could begin to realize this potential.

The findings are published in the peer-reviewed journal Optics Express on July 13th, 2020.

The 'terahertz gap' is a term used by engineers to describe how very little technology exists that makes use of the frequency band in the electromagnetic spectrum that lies between microwaves and infrared radiation: terahertz radiation (also called T-rays).

While it is straightforward to generate and manipulate microwaves and infrared radiation, practical technologies that operate at room temperature and that are able to do the same with T-rays are inefficient and impractical.

This is a great shame, as the properties of T-rays would make them extremely useful if we could indeed harness them.

T-rays can penetrate opaque objects like X-rays, but they are non-ionizing, so much safer. They can also go through clothing, wood, plastics, and ceramics, so are of interest for the security and surveillance sector for real-time imaging to identify concealed guns or explosives. For this same reason, terahertz radiation applications are also promising for cultural heritage science, offering art historians and museums a no-radiation risk option for investigation of artifacts ranging from paintings to mummies.

Terahertz technology that allows generation, detection, and application of terahertz waves has taken off in the last decade or so, closing the terahertz gap somewhat. But the performance and dimensions of conventional optical components able to manipulate terahertz waves have not kept up with this rapid development. One reason is the lack of naturally occurring materials suitable for the terahertz waveband.

However, researchers at Tokyo University of Agriculture and Technology (TUAT) led by Associate Professor and terahertz wave engineer Takehito Suzuki have recently developed an optical component that can more easily manipulate T-rays and in a practical fashion--by using a material that doesn't occur in nature.

Conventionally, a collimator--a device that narrows beams or waves, typically consisting of a curved lens or mirror--that can manipulate T-rays is a bulky three-dimensional structure made of naturally occurring materials.

But the TUAT researchers, Takehito Suzuki, Kota Endo, and Satoshi Kondoh, have devised a collimator as an ultra-thin (2.22 micrometers) plane made from a 'metasurface'--a material that is engineered to have properties that are impossible or difficult to find in nature. These properties come not from whatever metal or plastic base substance they are composed of, but instead from the geometry and arrangement of the material in tiny repeating patterns that can bend electromagnetic waves in a way that natural substances cannot.

In this case, the material has an extremely high refractive index (how slow light travels through it) and low reflectance (proportion of light reflected after striking a surface). The collimator consists of 339 pairs of meta-atoms arranged so that the refractive index concentrically increases from the outside to the center of the device.

"The metasurface design is unprecedented," said Suzuki, "delivering a much higher performance that should accelerate the development of a wide range of applications, including next-generation wireless communications (6G/7G) and even thermal radiation control devices."

Research led by scientists at The Australian National University (ANU) could lead to major improvements in crop production.

The study shows a new way to help study and ramp up photosynthesis. The breakthrough is based on revisiting an original, billion-year-old strategy in plants.

It looks specifically at rubisco activity - a crucial part of the process according to co-author Professor Spencer Whitney from the ARC Centre of Excellence for Translational Photosynthesis at ANU.

"Rubisco is an enzyme involved in the first step of carbon fixation - it starts the conversion of carbon dioxide into plant sugars," he said.

"But compared to other enzymes, rubisco is considered a slow, inefficient catalyst.

"Many enzymes can process hundreds to thousands of molecules per second, but rubisco can only get through two to five cycles per second.

"For this reason, it's long been recognised as a good target for improving photosynthesis -- it's a puzzle scientists have been looking at for decades."

In plants rubisco is made up of 16 proteins - eight large and eight small subunits. Until now scientists have only been able to tinker with one subunit at a time.

"We've now turned back the clock a billion years to rectify this limitation," Professor Whitney said.

"By reapplying the genome design of the bacterial ancestors of chloroplasts we can now play around with all the components of rubisco simultaneously.

"This is crucial. To ramp up its activity you have to make changes to all the components."

It could mean big gains for canola and potato crop in particular.

"We know we can already tinker with rubisco activity in these crops, so it's a great place to start," Professor Whitney said.

"This is the just the first step - this technology could eventually deliver something much bigger in the not so distant future."

Medicated chewing gum has been recognised as a new advanced drug delivery method but currently there is no gold standard for testing drug release from chewing gum in vitro. New research has shown a chewing robot with built-in humanoid jaws could provide opportunities for pharmaceutical companies to develop medicated chewing gum.

The aim of the University of Bristol study, published in IEEE Transactions on Biomedical Engineering, was to confirm whether a humanoid chewing robot could assess medicated chewing gum. The robot is capable of closely replicating the human chewing motion in a closed environment. It features artificial saliva and allows the release of xylitol the gum to be measured.

The study wanted to compare the amount of xylitol remaining in the gum between the chewing robot and human participants. The research team also wanted to assess the amount of xylitol released from chewing the gum.

The researchers found the chewing robot demonstrated a similar release rate of xylitol as human participants. The greatest release of xylitol occurred during the first five minutes of chewing and after 20 minutes of chewing only a low amount of xylitol remained in the gum bolus, irrespective of the chewing method used.

Saliva and artificial saliva solutions respectively were collected after five, ten, 15 and 20 minutes of continuous chewing and the amount of xylitol released from the chewing gum established.

Dr Kazem Alemzadeh, Senior Lecturer in the Department of Mechanical Engineering, who led the research, said: "Bioengineering has been used to create an artificial oral environment that closely mimics that found in humans.

"Our research has shown the chewing robot gives pharmaceutical companies the opportunity to investigate medicated chewing gum, with reduced patient exposure and lower costs using this new method."

Nicola West, Professor in Restorative Dentistry in the Bristol Dental School and co-author, added: "The most convenient drug administration route to patients is through oral delivery methods. This research, utilising a novel humanoid artificial oral environment, has the potential to revolutionise investigation into oral drug release and delivery."

Researchers of Peter the Great St.Petersburg Polytechnic University(SPbPU) in collaboration with colleagues from Tsinghua University (China) developed a new dynamic light scattering method to determine the sizes of circulating immune complexes in blood serum. The results of the study were published in the first quartile Biology Journal, MDPI Publishing House. Scientists mentioned, that this method is fast, contactless, safe and cheap. That why it could be used in blood screening studies, for example, as part of regular medical examinations.

The scientific group of the Higher School of Applied Physics and Space Technologies SPbPU investigated how the immune complexes are formed in blood serum. The immune complexes are molecular aggregates, which consist of antigens, antibodies, and proteins of the immune system. The size and concentration of such immune complexes indicate the state of the immune system. Normally a certain concentration of the immune complexes presents in blood serum, high concentration of immune complexes is formed due to the pathological condition.

The international scientific group investigated the blood serum of donors with various pathologies, such as autoimmune diseases, cancer, diabetes mellitus, etc.

According to scientists the increased (compared with the average) size of the immune complexes indicates the presence of diseases, and by itself can have a potentially negative effect on the state of the body. A high concentration of the newly formed immune complexes can disrupt the functioning of the immune system. These complexes can clog microcapillaries, or accumulate in the tissues, causing chronic inflammatory processes.

"We found out, that the infection in the body leads to the formation of a large number of the immune complexes in the blood," said Elina Nepomnyashchaya, an employee of the Laboratory for Laser Photometry and Spectroscopy of St. Petersburg Polytechnic University.

Elena Velichko, Head of the Laboratory of Laser Photometry and Spectroscopy SPbPU, notes: "Our method is quite fast, it doesn't require the use of specific expensive antigens. Its work is based on the interaction of laser radiation with serum or plasma proteins. Using the developed method, we were able to trace the activation path of the immune system in the blood. Our results can be used in pharmacology for drug testing and in the modern preventive diagnosis of immune diseases."

The research is carried out jointly with medical institutions of St. Petersburg (Russia). In future, the scientific group plans to conduct research with the fellow biologists to determine how different substances affect the activation of the immune system.

Subsequently, scientists plan to study the disorders of the immune system due to cancer. Researchers hope to "teach" the immunity to recognize the cancer cells and to recover.

Especially activities in the field of artificial intelligence, like teaching robots to walk or precise automatic image recognition, demand ever more powerful, yet at the same time more economical computer chips. While the optimization of conventional microelectronics is slowly reaching its physical limits, nature offers us a blueprint how information can be processed and stored quickly and efficiently: our own brain. For the very first time, scientists at TU Dresden and the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have now successfully imitated the functioning of brain neurons using semiconductor materials. They have published their research results in the journal Nature Electronics (DOI: 10.1038/s41928-020-0412-1).

Today, enhancing the performance of microelectronics is usually achieved by reducing component size, especially of the individual transistors on the silicon computer chips. "But that can't go on indefinitely - we need new approaches", Larysa Baraban asserts. The physicist, who has been working at HZDR since the beginning of the year, is one of the three primary authors of the international study, which involved a total of six institutes. One approach is based on the brain, combining data processing with data storage in an artificial neuron.

"Our group has extensive experience with biological and chemical electronic sensors," Baraban continues. "So, we simulated the properties of neurons using the principles of biosensors and modified a classical field-effect transistor to create an artificial neurotransistor." The advantage of such an architecture lies in the simultaneous storage and processing of information in a single component. In conventional transistor technology, they are separated, which slows processing time and hence ultimately also limits performance.

Silicon wafer + polymer = chip capable of learning

Modeling computers on the human brain is no new idea. Scientists made attempts to hook up nerve cells to electronics in Petri dishes decades ago. "But a wet computer chip that has to be fed all the time is of no use to anybody," says Gianaurelio Cuniberti from TU Dresden. The Professor for Materials Science and Nanotechnology is one of the three brains behind the neurotransistor alongside Ronald Tetzlaff, Professor of Fundamentals of Electrical Engineering in Dresden, and Leon Chua from the University of California at Berkeley, who had already postulated similar components in the early 1970s.

Now, Cuniberti, Baraban and their team have been able to implement it: "We apply a viscous substance - called solgel - to a conventional silicon wafer with circuits. This polymer hardens and becomes a porous ceramic," the materials science professor explains. "Ions move between the holes. They are heavier than electrons and slower to return to their position after excitation. This delay, called hysteresis, is what causes the storage effect." As Cuniberti explains, this is a decisive factor in the functioning of the transistor. "The more an individual transistor is excited, the sooner it will open and let the current flow. This strengthens the connection. The system is learning."

Cuniberti and his team are not focused on conventional issues, though. "Computers based on our chip would be less precise and tend to estimate mathematical computations rather than calculating them down to the last decimal," the scientist explains. "But they would be more intelligent. For example, a robot with such processors would learn to walk or grasp; it would possess an optical system and learn to recognize connections. And all this without having to develop any software." But these are not the only advantages of neuromorphic computers. Thanks to their plasticity, which is similar to that of the human brain, they can adapt to changing tasks during operation and, thus, solve problems for which they were not originally programmed.

Vibrations of atoms in a crystal of the semiconductor gallium arsenide (GaAs) are impulsively shifted to a higher frequency by an optically excited electric current. The related change in the spatial distribution of charge between gallium and arsenic atoms acts back on their motions via electric interactions.

To hammer-on a guitar, a technique deployed by many rock guitarists, means to shorten a vibrating string quickly with a second finger and, thus, switch to a higher tone. This technique allows for faster playing and legato, a smoother linking of subsequent tones. Researchers from Berlin and Paris have now demonstrated a hammer-on analogue in crystals by switching the frequency of atomic motions with an impulsively generated electric current. As they report in the most recent issue of the journal Physical Review Letters, an electric current generated by femtosecond optical excitation shifts particular lattice vibrations, the transverse optical (TO) phonons, to a higher frequency.

The crystal lattice of GaAs consists of a regular arrangement of gallium and arsenic atoms (Fig. 1) held together by covalent chemical bonds. The atoms in the lattice can undergo a variety of vibrations, among them the TO phonon with a frequency of 8 THz = 8 000 000 000 000 vibrations per second. The electron density on the arsenic atoms is somewhat higher than on the gallium atoms, leading to a local electric dipole moment and making the crystal lattice electrically polar. This property makes the vibrational motion susceptible to electric forces.

In the experiments, a first femtosecond optical pulse launches a TO phonon oscillation, which is disturbed by a second pulse exciting electrons from the valence to the conduction band of the semiconductor. This excitation is connected with a shift of local charge, i.e., a so-called electric shift current. The shift current enhances the electron density on the gallium atoms. This change in the crystal's electron distribution leads to a transient electric polarization, which generates an electric force and, thus, acts back on the TO phonon motion. As a result, the TO phonon frequency in the excited crystal changes by a small amount.

The measurement of the tiny phonon frequency shift represents a big experimental challenge. In the present study, the TO phonon oscillation was mapped in real-time via the THz wave radiated from the oscillating phonon dipole moment. The THz wave was measured in amplitude and phase with extremely high precision (Fig. 2). The radiated THz wave displays a frequency up-shift after the second pulse has interacted with the sample. The frequency shift is obvious from the slightly shorter oscillation period of the THz wave (red trace in Fig. 2) compared to the case without the second pulse (black trace). The up-shift of the TO phonon frequency has a value of 100 GHz or approximately 1 percent of the initial frequency. An analysis of the experimental results shows that one photo-excited electron in a crystal volume of 20 000 GaAs unit cells induces the one-percent frequency up shift.

The change of TO phonon frequency observed here for the first time should also occur in a wider range of semiconductors with a polar lattice and in ferroelectric materials.

Nine out of 10 U.S. men ages 18 to 35 support health care providers asking about intimate partner violence, according to new survey analysis. Data from a 2014 nationally representative survey showed that while most men support health care-based intimate partner violence screenings, only about 10 percent reported being asked by their doctor. Men who reported lower levels of education were most likely to be asked, but support for screenings varied by race and past experience with such violence. Black non-Hispanic men were less likely to think doctors should ask. Victims of intimate partner violence were more likely to support screening. The study notes that overall, about 17 percent of the 916 respondents reported experiences of physical violence with their partners, and a majority of men--56 percent--said they had been both a victim and perpetrator. Authors note that, "When young men seek health care with their primary care physician, those health care encounters offer opportunities to identify intimate partner violence." Understanding the attitudes and experiences of men may help primary care clinicians tailor their conversations, support and referrals.

Prevalence of Intimate Partner Violence and Beliefs About Partner Violence Screening Among Young Men
Tova B. Walsh, PhD, et al
University of Wisconsin-Madison, School of Social Work, Madison, Wisconsin
https://www.annfammed.org/content/18/4/303

WASHINGTON (July 14, 2020)--Smartphone owners who unlock their devices with knock codes aren't as safe as they think, according to researchers from New Jersey Institute of Technology, the George Washington University and Ruhr University Bochum.

Knock codes work by letting people select patterns to tap on a phone's locked screen. LG popularized the method in 2014, and now there are approximately 700,000 people using this method in the U.S. alone, along with one million downloads worldwide of clone applications for Google Android devices generally, the researchers said.

Raina Samuel, a doctoral student in computer science at NJIT's Ying Wu College of Computing, said she had the idea for this research while attending a security conference in 2017.

"During that conference I heard our co-author Adam Aviv give a presentation. He was talking about passwords, PINs, shoulder surfing and how these mobile methods of authentication can be manipulated and insecure sometimes," she said. "At the time, I had an LG phone and I was using the knock codes. It was a bit of a personal interest for me."

Knock codes typically present users with a 2-by-2 grid, which must be tapped in the correct sequence to unlock their phone. The sequence is between six and ten taps. The researchers analyzed how easily an attacker could guess a tapping pattern.

In an online study, 351 participants picked codes. The researchers found that 65% of users started their codes in the top left corner, often proceeding to the top right corner next, which could be attributed to Western reading habits. They also found that increasing the size of the grid didn't help, instead making the users more likely to pick shorter codes.

"Knock codes really intrigued me as I have spent a lot of time working on other mobile authentication options, such as PINs or Android patterns, and had never heard of these," Aviv, an associate professor of computer science at GW, said. "Turns out, while less popular than PINs or patterns, there are still a surprising number of people using knock codes, so it's important to understand the security and usability properties of them."

The researchers also tested a blocklist of common codes, so that survey participants would pick something harder to guess. The list contained the 30 most popular codes. The first three were:

Top left, top right, bottom left, bottom right, top left, top right (Hourglass shape)

Top left, top right, bottom right, bottom left, top left, top right (Square shape)

Top left, top left, top right, top right, bottom left, bottom left. (Number 7 shape)

The researchers said there should be a feature that blocks codes which are too easy to guess and advises users to pick stronger ones, similar to how some websites respond when users create password-protected accounts.

The study showed that knock codes are difficult to memorize. Approximately one in ten participants forgot their code by the end of the study, even though it lasted only five minutes. In addition, entering such a code to unlock the display took 5 seconds on average, compared to entering a PIN which typically takes 4.5 seconds and an Android unlock pattern needing only 3 seconds.

The research team also included Ruhr University's Philipp Markert. Aviv asked Markert to join their project when peer reviewers said the study of knock code patterns should be done on phones, not on computer simulations. Markert adapted the study's programming for this change.

"I'm always interested in new authentication schemes, and I worked with Adam on a similar project about PINs, so when he asked me to join the team, I didn't think twice." Markert said.

The paper will be presented at the 16th Symposium on Usable Privacy and Security, held concurrently with the prestigious USENIX Security Symposium August 9-11. Funding was supplied by the Army Research Laboratory, National Science Foundation and Germany's North Rhine-Westphalian Experts on Research in Digitalization.

TORONTO, July 14, 2020 - Climate change and an increase in disturbed bee habitats from expanding agriculture and development in northeastern North America over the last 30 years are likely responsible for a 94 per cent loss of plant-pollinator networks, York University researchers found.

The researchers, corresponding author Professor Sandra Rehan of the Faculty of Science and grad student Minna Mathiasson of the University of New Hampshire, looked at plant-pollinator networks from 125 years ago through present day. The networks are comprised of wild bees and the native plants they historically rely on, although most of those have now been disrupted.

About 30 per cent of plant-pollinator networks were completely lost, which translates to a disappearance of either the bees, the plants or both. In another 64 per cent of the network loss, the wild bees, such as sweat or miner bees, or native plants, such as sumac and willow, are still present in the eco-system, but the bees no longer visit those plants. The association is gone.

The remaining six per cent of the plant-pollinator networks are stable or even thriving with pollinators such as small carpenter bees, which like broken stems for nest making.

"There are several reasons for the losses in the networks. Climate change is likely the biggest driver. We know that over the last 100 years or so annual temperatures have changed by two and a half degrees. This is enough to alter the time when certain native plants bloom," says Rehan.

"For a bee that's out for months on end or is a generalist pollinator, this isn't such a critical mismatch, but for a bee that's only out for two weeks of the year and only has a few floral hosts, this could be devastating."
An increase in non-native species of bees and invasive species of plants, which have displaced some of the native species, is another reason for the decline in networks.

"We are getting a lot of invasive species and new records of invasive species every year. This is usually accidentally through trade and through ornamental plants," says Rehan.

A lot of these bees live in stems, so it's easy to import plants with non-native bee species without knowing it. "We can actually show routes and means of invasion biology," she says.

These bees are following shipping routes from one continent to the other around the world, including North America through ornamental plants for our gardens.

The researchers say an increase in habitat restoration and native flowering plants in agricultural landscapes are critical for improving wild bee biodiversity, but also food security for humans.

Bees and other pollinators are worth hundreds of billions of dollars globally by pollinating the crops we eat, and wild bees are at the top of the list believed to pollinate more than 87 per cent or 308,006 flowering plant species. Many of these are economically important commercial crops, such as apples and blueberries.

"There is an urgent need to gain a deeper understanding of the environmental circumstances affecting these wild pollinator populations and their specialised, evolutionary relationships with plant communities," says Rehan. "Plant pollinator webs are dependent on changes in the landscape, so knowing how these networks are shaped is important for all regional habitats."

Previous recent research by Rehan and team looked at 119 wild bee species over 125 years and found 14 declining and eight increasing species. All of the wild bee species in decline are native and over half experienced significant range (latitude and elevation) shifts.

The authors of this study developed a single risk score derived from multiple social determinants of health that predicts county-level cardiovascular disease mortality. Using data culled from government resources, they identified U.S. counties with a high risk of CVD based on a three-year average mortality rate. They used a 50 percent random sample of 3,026 counties to develop a risk score based on seven social determinants of health factors: proportion of non-white population, poverty rate, proportion of population without high school diploma, grocery store ratio, fast-food restaurant ratio, after-tax soda price and primary care physician supply. The remaining 50 percent of the counties served to validate the measure. The resulting index had better predictive performance for CVD burden than common single-measure area-level indexes (e.g., only measuring poverty). The authors conclude that their multivariable SDoH risk score can identify counties with high CVD risk and has the potential to improve CVD risk prediction and interventions for vulnerable populations at the county level.

This study analyzes patterns of participation in the Comprehensive Primary Care Plus initiative which is the largest voluntary primary care payment and delivery reform model tested to date. Of the nearly 20,000 primary care practices within the 18 regions selected by the Centers for Medicare and Medicaid Services for CPC+ implementation, 22 percent applied to participate. CMS accepted all applicants that met their minimum criteria, reflecting 15 percent of all primary care practices in the regions. Participation rates varied across the 18 regions from 2 percent to 34 percent. The Mathematica research team found that applicant practices, while diverse, were more likely to be larger, to be owned by a hospital or health system, to have experience with transformation efforts, and to be located in urban areas than practices that did not apply. Applicants also generally served slightly healthier and more advantaged Medicare fee-for-service beneficiaries. Overall, participating practices were not necessarily representative of all primary care practices in their region, underscoring the need to further engage practices that are small, independent, in rural areas, and lack experience with practice and payment transformation models, and the need to extrapolate evaluation results carefully.