Culture

CHAMPAIGN, Ill. -- Scientists have known for decades that aerobic exercise strengthens the brain and contributes to the growth of new neurons, but few studies have examined how yoga affects the brain. A review of the science finds evidence that yoga enhances many of the same brain structures and functions that benefit from aerobic exercise.

The review, published in the journal Brain Plasticity, focused on 11 studies of the relationship between yoga practice and brain health. Five of the studies engaged individuals with no background in yoga practice in one or more yoga sessions per week over a period of 10-24 weeks, comparing brain health at the beginning and end of the intervention. The other studies measured brain differences between individuals who regularly practice yoga and those who don't.

Each of the studies used brain-imaging techniques such as MRI, functional MRI or single-photon emission computerized tomography. All involved Hatha yoga, which includes body movements, meditation and breathing exercises.

"From these 11 studies, we identified some brain regions that consistently come up, and they are surprisingly not very different from what we see with exercise research," said University of Illinois kinesiology and community health professor Neha Gothe, who led the research with Wayne State University psychology professor Jessica Damoiseaux.

"For example, we see increases in the volume of the hippocampus with yoga practice," Gothe said. Many studies looking at the brain effects of aerobic exercise have shown a similar increase in hippocampus size over time, she said.

The hippocampus is involved in memory processing and is known to shrink with age, Gothe said. "It is also the structure that is first affected in dementia and Alzheimer's disease."

Though many of the studies are exploratory and not conclusive, the research points to other important brain changes associated with regular yoga practice, Damoiseaux said. The amygdala, a brain structure that contributes to emotional regulation, tends to be larger in yoga practitioners than in their peers who do not practice yoga. The prefrontal cortex, cingulate cortex and brain networks such as the default mode network also tend to be larger or more efficient in those who regularly practice yoga.

"The prefrontal cortex, a brain region just behind the forehead, is essential to planning, decision-making, multitasking, thinking about your options and picking the right option," Damoiseaux said. "The default mode network is a set of brain regions involved in thinking about the self, planning and memory."

Like the amygdala, the cingulate cortex is part of the limbic system, a circuit of structures that plays a key role in emotional regulation, learning and memory, she said.

The studies also find that the brain changes seen in individuals practicing yoga are associated with better performance on cognitive tests or measures of emotional regulation.

The discovery that yoga may have similar effects on the brain to aerobic exercise is intriguing and warrants more study, Gothe said.

"Yoga is not aerobic in nature, so there must be other mechanisms leading to these brain changes," she said. "So far, we don't have the evidence to identify what those mechanisms are."

She suspects that enhancing emotional regulation is a key to yoga's positive effects on the brain. Studies link stress in humans and animals to shrinkage of the hippocampus and poorer performance on tests of memory, for example, she said.

"In one of my previous studies, we were looking at how yoga changes the cortisol stress response," Gothe said. "We found that those who had done yoga for eight weeks had an attenuated cortisol response to stress that was associated with better performance on tests of decision-making, task-switching and attention."

Yoga helps people with or without anxiety disorders manage their stress, Gothe said.

"The practice of yoga helps improve emotional regulation to reduce stress, anxiety and depression," she said. "And that seems to improve brain functioning."

The researchers say there is a need for more - and more rigorous - research into yoga's effects on the brain. They recommend large intervention studies that engage participants in yoga for months, match yoga groups with active control groups, and measure changes in the brain and performance on cognitive tests using standard approaches that allow for easy comparisons with other types of exercise.

"The science is pointing to yoga being beneficial for healthy brain function, but we need more rigorous and well-controlled intervention studies to confirm these initial findings," Damoiseaux said.

Leading scholars and publishers from The Ottawa Hospital's Centre for Journalology, the University of Ottawa's Telfer School of Management, and other institutions from around the world have agreed on a consensus definition of predatory publishing.

Led by Drs. Agnes Grudniewicz, David Moher, Kelly Cobey, and Manoj Lalu, their commentary was published in Nature.

Predatory journals are a global threat to quality science that was largely unknown a decade ago. There are now an estimated 8,000 predatory journals collectively publishing more than 400,000 research studies each year.

One of the challenges of solving this problem was that there was no agreed-upon definition of predatory publications-- until now.

At a recent international meeting in Ottawa, the team of experts reached this consensus definition: "Predatory journals and publishers are entities that prioritize self-interest at the expense of scholarship and are characterized by false or misleading information, deviation from best editorial and publication practices, a lack of transparency, and/or the use of aggressive and indiscriminate solicitation practices."

This definition will let researchers track predatory publishing, and develop educational resources and interventions to help fight this growing problem.

LAWRENCE -- If you're prone to depression, this holiday season you might want to say "bah humbug" to offers of sugar plum pudding, caramel corn and chocolate babka.

A new study from a team of clinical psychologists at the University of Kansas suggests eating added sugars - common in so many holiday foods - can trigger metabolic, inflammatory and neurobiological processes tied to depressive illness. The work is published in the journal Medical Hypotheses.

Coupled with dwindling light in wintertime and corresponding changes in sleep patterns, high sugar consumption could result in a "perfect storm" that adversely affects mental health, according to the researchers.

"For many people, reduced sunlight exposure during the winter will throw off circadian rhythms, disrupting healthy sleep and pushing five to 10% of the population into a full-blown episode of clinical depression," said Stephen Ilardi, KU associate professor of clinical psychology.

Ilardi, who coauthored the study with KU graduate students Daniel Reis (lead author), Michael Namekata, Erik Wing and Carina Fowler (now of Duke University), said these symptoms of "winter-onset depression" could prompt people to consume more sweets.

"One common characteristic of winter-onset depression is craving sugar," he said. "So, we've got up to 30% of the population suffering from at least some symptoms of winter-onset depression, causing them to crave carbs - and now they're constantly confronted with holiday sweets."

Ilardi said avoidance of added dietary sugar might be especially challenging because sugar offers an initial mood boost, leading some with depressive illness to seek its temporary emotional lift.

"When we consume sweets, they act like a drug," said the KU researcher, who also is author of "The Depression Cure" (First De Capo Press, 2009). "They have an immediate mood-elevating effect, but in high doses they can also have a paradoxical, pernicious longer-term consequence of making mood worse, reducing well-being, elevating inflammation and causing weight gain."

The investigators reached their conclusions by analyzing a wide range of research on the physiological and psychological effects of consuming added sugar, including the Women's Health Initiative Observational Study, the NIH-AARP Diet and Health Study, a study of Spanish university graduates, and studies of Australian and Chinese soda-drinkers.

Ilardi cautioned it might be appropriate to view added sugar, at high enough levels, as physically and psychologically harmful, akin to drinking a little too much liquor.

"We have pretty good evidence that one alcoholic drink a day is safe, and it might have beneficial effect for some people," he said. "Alcohol is basically pure calories, pure energy, non-nutritive and super toxic at high doses. Sugars are very similar. We're learning when it comes to depression, people who optimize their diet should provide all the nutrients the brain needs and mostly avoid these potential toxins."

The researchers found inflammation is the most important physiological effect of dietary sugar related to mental health and depressive disorder.

"A large subset of people with depression have high levels of systemic inflammation," said Ilardi. "When we think about inflammatory disease we think about things like diabetes and rheumatoid arthritis - diseases with a high level of systemic inflammation. We don't normally think about depression being in that category, but it turns out that it really is - not for everyone who's depressed, but for about half. We also know that inflammatory hormones can directly push the brain into a state of severe depression. So, an inflamed brain is typically a depressed brain. And added sugars have a pro-inflammatory effect on the body and brain."

Ilardi and his collaborators also identify sugar's impact on the microbiome as a potential contributor to depression.

"Our bodies host over 10 trillion microbes and many of them know how to hack into the brain," Ilardi said. "The symbiotic microbial species, the beneficial microbes, basically hack the brain to enhance our well-being. They want us to thrive so they can thrive. But there are also some opportunistic species that can be thought of as more purely parasitic - they don't have our best interest in mind at all. Many of those parasitic microbes thrive on added sugars, and they can produce chemicals that push the brain in a state of anxiety and stress and depression. They're also highly inflammatory."

Ilardi recommended a minimally processed diet rich in plant-based foods and Omega-3 fatty acids for optimal psychological benefit. As for sugar, the KU researcher recommended caution - not just during the holidays, but year-round.

"There's no one-size-fits-all approach to predicting exactly how any person's body will react to any given food at any given dose," Ilardi stated. "As a conservative guideline, based on our current state of knowledge, there could be some risk associated with high-dose sugar intake - probably anything above the American Heart Association guideline, which is 25 grams of added sugars per day."

Background

Optical switches will be important components in future photonic integrated circuits for ultrafast information processing. Optical switches control the on/off state or the direction of optical signals, and the switching speed depends on whether the optical signals are optically or electrically controlled. All-optical switches control optical signals with other optical signals, so they are unaffected by the RC time constant3, which limits the operation speed of electrical devices. Thus, it has been expected that all-optical switches will operate faster than electrically controlled ones. However, the switching energies of the previously reported all-optical switches are relatively large. This energy problem is a critical one for ultrafast information processing because optical components must be densely integrated in photonic circuits and the energy consumption of each device must be low. As shown in Fig. 1, high speed and low energy consumption have not been achieved simultaneously with the previously reported all-optical switches, and it had been assumed that a trade-off existed between the switching energy and switching time. In 2020, however, NTT overcame this trade-off and demonstrated all-optical switching with an extremely small driving energy by using a photonic crystal nanocavity with modest operating speed (tens of picoseconds). On the other hand, the trade-off still remained in the ultrafast switching regime (less than one picosecond), which is beyond the capability of electrical control.

Achievements

NTT and Tokyo Tech developed an all-optical switch operating in the ultrafast regime (less than one picosecond) with low energy consumption by combining an extremely small optical nanoscale waveguide based on plasmonics4 with graphene (Fig. 2a). The main points are as follows.

[1] Enhancement of absorption and nonlinear optical effect5 in graphene with plasmonic waveguides

To control optical signals with other optical signals, the properties of a material placed on the optical path must be changed with light, and the response time (i.e., the time in which this change occurs) is the one of the limitations on the switching time. Here, we employed graphene, which has an ultrafast nonlinear optical response. Graphene is not only a promising for its speed; it also has a large absorption coefficient6 over a broadband wavelength range. On the other hand, graphene is only one-atom thick, and the interaction with light is weak, which leads to long photonic devices and high energy consumption. In this work, we overcame this problem by strongly confining light within a nanoscale plasmonic waveguide.

We fabricated small plasmonic waveguides with a core size of 30 nm × 20 nm and loaded graphene on them by using NTT's nanofabrication technologies (Fig. 2b). The cross-sectional area of these plasmonic waveguides is about 1/100th that of "compact" silicon waveguides and 1/105 that of single-mode optical fibers. It was experimentally shown that the absorption coefficient of the graphene-loaded plasmonic waveguide is one order of magnitude smaller than that of graphene-loaded silicon waveguides. Moreover, the energy required for inducing nonlinear optical effects is four orders of magnitude smaller. These results show that compactness and low energy consumption can be achieved at the same time.

[2] Demonstration of ultrafast all-optical switching

The signal light is switched (on/off) with control light in all-optical switches (Fig. 3a). In our switch, the control light induces a nonlinear optical effect of graphene; i.e., it changes the degree of absorption by graphene. Figure 3b indicates that a switching time of 260 fs can be achieved with a switching energy of 35 fJ. The switching time is one order of magnitude shorter and the energy four orders of magnitude smaller than those of previous graphene-based devices. In addition, as shown in Fig. 1, the switching energy is the smallest value ever reported (1/100th of that previously reported) for any type of all-optical switch operating at less than one picosecond. Thus, we developed the first all-optical switch operating with a response time in the femtosecond range and an energy consumption in the femtojoule range. Moreover, the energy-time product, which is a measure of the trade-off mentioned above, was somewhat improved over that of the previous best device.

Outlook

NTT and Tokyo Tech are working on overcoming the limitations of electronics, such as on the operation speed and energy consumption, by integrating a dense photonic network into a processor chip. The all-optical switch operates much faster than an electrically controlled one and consumes less energy. We expect that it will be used in future photonic integrated circuits for ultrafast information processing. As well, the nanoscale waveguide of the switch is a superior platform for developing nanophotonic information processing devices incorporating nanowires and other two-dimensional materials. Moreover, we envision that our device can be used as a nonlinear activation function in optical neural networks. In the future, we will increase the performance of the all-optical switch, apply its technology to other photonic devices such as detectors, and examine the use of other nanomaterials.

Technical features

[1] Ultrafast nonlinear optical effect in graphene

We employed graphene for ultrafast operation. Monolayer graphene absorbs 2.3% of light over a broadband wavelength range (from visible to infrared), and this value means that graphene has a much larger absorption coefficient than that of conventional semiconductors. In addition, graphene shows saturable absorption7, a nonlinear optical effect, and its response time can be less than 100 fs. This ultrafast response originates from the very short relaxation times of graphene carriers. In our switch, a transmittance change induced by saturable absorption switches the on/off state, and the absorption saturates as a result of photo-excited carriers.

[2] Enhancement of the interaction between graphene and light by plasmonics

Graphene is a promising nonlinear optical material, but it is too thin to be used in optical devices. Here, we utilized a plasmonic waveguide with a height and width of a few tens of nanometers to enhance the interaction between graphene and light. Plasmonic waveguides strongly confine light--with a core width of only 30 nm and height of only 20 nm, the core area of our waveguide is as small as λ2/4000 (wavelength λ; in this case is 1550 nm). The interaction between graphene and light is weak when a conventional waveguide made of silicon is used; a numerical calculation gives an absorption coefficient of 0.089 dB/μm (2% per μm) for a graphene-loaded silicon waveguide with a core measuring 400 nm x 200 nm. This means that a device longer than 30 μm would be needed to obtain 50% absorption. On the other hand, the absorption coefficient for a plasmonic waveguide is estimated to be much higher, 2.0 dB/μm (37% per μm) for a core size of 30 nm x 20 nm, which enables the device length to be decreased. Furthermore, the light intensity at the position of the graphene is 310 times larger than that for a silicon waveguide because the plasmon waveguide core is much smaller. This enhancement significantly reduces the switching energy.

The above enhancement effects were observed in experiments. In particular, the experimentally obtained absorption coefficient for the plasmonic waveguide was 1.7 dB/μm. In addition, the obtained saturation energy was 12 fJ, which is four orders of magnitude smaller than that for graphene-loaded silicon waveguide. Because an increase in light intensity can be regarded as a reduction of the saturation energy in saturable absorption, this result means that the light intensity was enhanced by four orders of magnitude.

[3] Overcoming the drawbacks of plasmonics with mode converters

Although plasmonic waveguides strongly confine light, they have a large propagation loss, and directly coupling light to them is not easy because their waveguide cores are much smaller than the wavelength of light. Thus, we utilized the plasmonic waveguides only for the interaction with graphene and used highly efficient plasmonic mode converters to connect the plasmonic waveguides to conventional low-loss dielectric waveguides. An advanced fabrication technique is needed to make this mode converter; here, NTT developed a plasmonic mode converter connecting a deep-subwavelength plasmonic waveguide and a silicon waveguide in 2016. The plasmonic mode converters enable us to fully enjoy the merits of plasmonic waveguides and graphene in photonic integrated circuits.

When astronomers see something in the universe that at first glance seems like one-of-a-kind, it's bound to stir up a lot of excitement and attention. Enter comet 2I/Borisov. This mysterious visitor from the depths of space is the first identified comet to arrive here from another star. We don't know from where or when the comet started heading toward our Sun, but it won't hang around for long. The Sun's gravity is slightly deflecting its trajectory, but can't capture it because of the shape of its orbit and high velocity of about 100,000 miles per hour.

Telescopes around the world have been watching the fleeting visitor. NASA's Hubble Space Telescope has provided the sharpest views as the comet skirts by our Sun. Since October the space telescope has been following the comet like a sports photographer following horses speeding around a racetrack. Hubble revealed that the heart of the comet, a loose agglomeration of ices and dust particles, is likely no more than about 3,200 feet across, about the length of nine football fields. Though comet Borisov is the first of its kind, no doubt there are many other comet vagabonds out there, plying the space between stars. Astronomers will eagerly be on the lookout for the next mysterious visitor from far beyond.

These two images, taken by Hubble, capture comet 2I/Borisov streaking though our solar system and on its way back to interstellar space. It is only the second interstellar object known to have passed through the solar system.

Nov. 16, 2019, photo

The comet appears in front of a distant background spiral galaxy (2MASX J10500165-0152029). The galaxy's bright central core is smeared in the image because Hubble was tracking the comet. Comet Borisov was approximately 203 million miles from Earth in this exposure. Its tail of ejected dust streaks off to the upper right. The comet has been artificially colored blue to discriminate fine detail in the halo of dust, or coma, surrounding the central nucleus. It also helps to visually separate the comet from the background galaxy.

Dec. 9, 2019, photo

Hubble revisited the comet shortly after its closest approach to the Sun where it received maximum heating after spending most of its life in frigid interstellar space. The comet also reached a breathtaking maximum speed of about 100,000 miles per hour. Comet Borisov is 185 million miles from Earth in this photo, near the inner edge of the asteroid belt but below it. The nucleus, an agglomeration of ices and dust, is still too small to be resolved. The bright central portion is a coma made up of dust leaving the surface. The comet will make its closest approach to Earth in late December at a distance of 180 million miles.

"Hubble gives us the best upper limit of the size of comet Borisov's nucleus, which is the really important part of the comet," said David Jewitt, a UCLA professor of planetary science and astronomy, whose team has captured the best and sharpest look at this first confirmed interstellar comet. "Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be. Our Hubble images show that the radius is smaller than half a kilometer. Knowing the size is potentially useful for beginning to estimate how common such objects may be in the solar system and our galaxy. Borisov is the first known interstellar comet, and we would like to learn how many others there are."

Crimean amateur astronomer Gennady Borisov discovered the comet on Aug. 30, 2019, and reported the position measurements to the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts. The Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory in Pasadena, California, working with the Minor Planet Center, computed an orbit for the comet, which shows that it came from elsewhere in our Milky Way galaxy, point of origin unknown.

Nevertheless, observations by numerous telescopes show that the comet's chemical composition is similar to the comets found inside our solar system, providing evidence that comets also form around other stars. By the middle of 2020 the comet will have already zoomed past Jupiter's distance of 500 million miles on its way back into the frozen abyss of interstellar space.

A new image from NASA's Hubble Space Telescope provides important new details about the first interstellar comet astronomers have seen in our solar system.

The comet, called Comet 2I/Borisov (the "I" stands for interstellar), was spotted near a spiral galaxy known as 2MASX J10500165-0152029. It was approximately 203 million miles from Earth when the image was taken on Nov. 16.

"Data from the Hubble Space Telescope give us the best measure of the size of comet 2I/Borisov's nucleus, which is the really important part of the comet," said David Jewitt, a UCLA professor of planetary science and astronomy who analyzed and interpreted the data from the new image.

Jewitt collaborated on the new analysis with colleagues from the University of Hawaii, Germany's Max Planck Institute for Solar System Research, the Space Telescope Science Institute in Baltimore and Johns Hopkins University's Applied Physics Laboratory. The scientists were surprised to learn that the nucleus has a radius measuring only about half of a kilometer -- or less than one-fifteenth the size that earlier investigations suggested it might be.

"That is important because knowing its size helps us to determine the total number, and mass, of other similar objects in the solar system and the Milky Way," Jewitt said. "2I/Borisov is the first known interstellar comet, and we would like to learn how many others there are."

The comet is traveling at a breathtaking speed of 110,000 miles per hour -- one of the fastest comets ever seen, Jewitt said. More commonly, comets travel at about half that speed.

Crimean astronomer Gennady Borisov discovered the comet on Aug. 30, using a telescope he built. Based on precise measurements of its changing position, the International Astronomical Union's Minor Planet Center calculated a likely orbit for the comet, which shows that it came from elsewhere in the galaxy. Jewitt said its precise point of origin is unknown.

A second Hubble Space Telescope image of the comet, taken on Dec. 9, shows the comet even closer to Earth, approximately 185 million miles from Earth, he said.

Comets are icy bodies thought to be fragments left behind when planets form in the outer parts of planetary systems.

Observations by numerous telescopes show that the comet's chemical composition is similar to that of comets previously observed in our solar system, which provides evidence that comets also form around other stars, Jewitt said. By mid-2020, the comet will have zoomed past Jupiter on its way back into interstellar space, where it will drift for billions of years, Jewitt said.

New research suggests that, when two people must work together on a physical task despite conflicting goals, the amount of information available about each other's actions influences how quickly and optimally they learn to collaborate. Vinil Chackochan and Vittorio Sanguineti of the University of Genoa, Italy, present these findings in PLOS Computational Biology.

Most previous research into humans' ability to coordinate actions with others has addressed situations in which two people share a common goal, such as transporting a load or operating a tool. Much more often, people's goals conflict, and they must figure out how to collaborate. However, few studies have explored such situations.

For the new study, Chackochan and Sanguineti designed an experimental task in which two participants are assigned to perform different, competing sets of movements using the same mechanical apparatus at the same time. They also used Bayesian statistics and differential game theory to design a computational model that simulates similar partner situations.

Analysis of the experimental results and simulations revealed that, when one has more information about how a partner reacts to one's actions, collaboration is achieved more quickly, and one tends to develop optimal interaction strategies similar to those predicted by game theory. In contrast, with less information about one's partner, a person develops strategies that minimize the need for that information.

The findings provide new insights on the minimal computational machinery needed for stable physical collaboration. Understanding the mechanisms that underlie these kinds of human-human interactions could aid development of robots that can interact with people in a more natural, human-like fashion.

"Game theory has had a huge impact in many fields, including economics, political science, linguistics, operations research, and more," Chackochan says. "Application of game theory in human joint action may have far-reaching potential, especially in the area of human-robot interaction."

Next, the researchers plan to explore how people achieve and represent knowledge about a partner's ongoing actions and goals. They also aim to work towards development of a bio-inspired virtual agent with built-in collaborative capabilities.

London, UK: A recent study published in the journal Cephalalgia, the official journal of the International Headache Society, highlights an overlooked relationship between migraine and exercise. The study, entitled “Anxiety sensitivity and intentional avoidance of physical activity in women with probable migraine”, was led by Samantha G Farris, from Rutgers, Department of Psychology, the State University of New Jersey, NJ, USA.

Migraine affects around 10-15% of the population around the globe, and among its most common diagnosis criteria include a throbbing, unilateral head pain, hypersensitivity to lights, sounds, odors, and aggravation by activity. Although regular aerobic exercise has been strongly recommended by clinicians as an adjuvant option for migraine prevention, for up to 1/3 of patients, physical exercise can be a trigger of migraine attacks, thus, it can instead be avoided as a strategy to manage migraine. As observed with other pain conditions, anxiety sensitivity, which refers to one’s fear of experiencing anxiety arousal due to harmful physical, cognitive and socially-observable consequences, may be related to PA avoidance in migraine patients. This seems to be the true especially with vigorous PA, as this exercise intensity is perceived as potentially triggering or worsening of migraine attacks.

In this study, the researchers assessed 100 women with probable migraine, who filled an online survey covering anxiety sensitivity scores, intentional avoidance of moderate and vigorous physical activity (PA) in the past month, which was based on the Global Physical Activity Questionnaire (GPAQ), as well as the self-rated perception (0-100%) that PA would trigger a migraine attack and worse migraine symptoms.

The results showed that increased anxiety sensitivity scores associated with PA avoidance of both moderate and vigorous intensities. One-point increase in the anxiety sensitivity scale resulted in up to 5% increase in the odds for avoiding PA. Concerns about the physical consequences of bodily sensations (e.g. difficulty breathing) associated with a 7.5-fold higher odds for avoiding vigorous PA, while cognitive consequences of bodily sensations (e.g. inability to concentrate), which is thought to reflect headache-related disability, associated with a 5.2-fold higher odds for avoiding moderate PA. Anxiety sensitivity scores positively associated with stronger expectations of vigorous-intensity PA as a triggering and worsening factor for migraine.

This study revealed a relevant but overlooked aspect of migraine. Migraine is a highly prevalent and disabling neurological disorder, in which regular PA is part of current non-pharmacological treatment recommendations. As pointed out by the authors “Patients with migraine and elevated anxiety sensitivity could benefit from tailored, multi-component intervention, ideally including: Psychoeducation about the positive effect of PA on migraine and the detrimental effect of avoidance, feedback about the perceived versus actual rates of PA in triggering/worsening migraine, and use of gradual exposure to facilitate desensitization to avoided of PA and related bodily sensations.”

In today's criminal justice system, a Play Station and iPhone are just as important pieces of evidence as eyewitness accounts. Yet, there isn't a strong understanding as to how police officers identify digital evidence - everything from a laptop to a smart television - in the field.

Thomas Holt, professor of criminal justice at Michigan State University, is among the first researchers to capture how well police officers recognize digital evidence, as well as what to do with it.

"Digital evidence isn't part of the core police academy training, which is the baseline training all police recruits have when first going into the field," Holt said. "Since this training isn't consistently provided to them, how well would they recognize these critical pieces of evidence?"

The study - published in Policing: An International Journal - is based off a survey Holt conducted of 258 active state troopers and officers in the field. Holt gave the police a crime scene scenario in which they responded to a domestic violence call. From there, the police answered how they would respond and collect specific evidence on the crime scene.

Here are Holt's key findings:

1) Most - but not all - officers know who's the expert to call for support.

70% of the respondents said that they should contact the district prosecutor's office to ask what to do in a specific crime incident.

88% of officers said they knew who in that office is the right person.

"We can see that there's fairly consistent messaging around who to call in the event of a question," Holt said. "With digital evidence, it's difficult to know what to seize, or how to interact with it in a way that won't affect the information it holds. It's critical that all officers are aware of who the expert is to guide them in a delicate crime scene."

2) Not all officers know exactly what to look for.

76% said digital evidence could be anywhere in the scene.

43% said either on the wingspan of the suspect and victim or on the suspects or victim's person.

"We found that those who were familiar with digital evidence and seizing procedures were more likely to have responded recently to a scene where digital evidence was present," Holt said. "One big takeaway for us is that situational experience can help break down barriers and improve how police understand what to look for and where."

3) In the age of tech and smart homes, infinite pieces of evidence lay around the scene.

50% said to immediately seize all electronic items

91% said to secure mobile devices

90% said to secure any laptops

89% said to secure media storage devices

70% said to secure Amazon Echo/smart speaker

41% said to take the television

"There's a greater degree of recognition of what to do in the scene than I would have thought, like grabbing the Echo, the router or the TV," Holt said. "It's a very positive sign to see police knowing that storage devices are of great importance because any crimes that involve some sort of online activity or transactions - such as cyber security, child pornography or baking - could have evidence."

Holt explained that seeing degrees of digital evidence recognition - and it not varying across different age groups - is a positive sign, but there's work to be done.

"Our hope is that our research acts as baseline information for state agencies across the country," Holt said. "The huge takeaway or suggestion would be increasing training and awareness. We want them to start asking how well they train cadets to recognize devices in the field, what to do with it and how to improve as technology advances."

The brain determines when it is time to feed - but how does it know? Findings from St. Jude Children's Research Hospital provide new understanding of how the brain orchestrates this process. Skeletal muscle, like other tissues, communicates with the brain to convey information about nutritional status. The researchers showed that manipulating this mechanism influences food seeking and feeding in fruit flies. This work was published online today in Genes & Development.

Tissues like adipose, intestine and liver signal to the brain through hormones that regulate feeding behavior. Skeletal muscle makes up 40% of the human body and has high energy and nutrient demands. However, until now scientists did not appreciate how skeletal muscle can similarly communicate with the brain through signaling factors called myokines.

"Until now, the brain has been the least-studied target of myokine activity," said corresponding author Fabio Demontis, Ph.D., of the St. Jude Department of Developmental Neurobiology. "There are many myokines that act on other tissues, but their roles in signaling to the brain have been largely unexplored."

The molecular key to muscle-brain communication

To better understand how skeletal muscle communicates with the brain regarding feeding behavior, the researchers looked at the myokine Dpp in fruit flies. Dpp is the fruit fly equivalent of the BMP2 and BMP4 signaling factors in humans.

Scientists previously thought that Dpp only transmits signals at short distances. However, the researchers showed that fluorescently tagged Dpp travels long distances from the flight muscles of fruit flies to the brain. Furthermore, the researchers found that reducing Dpp levels promoted feeding and foraging behavior in fruit flies. Conversely, increasing Dpp levels reduced foraging and feeding.

A link between Dpp, dopamine and feeding initiation

The researchers also found that muscle-derived Dpp regulates the levels of brain tyrosine hydroxylase, an enzyme key to the synthesis of the neurotransmitter dopamine. Among a number of other roles, dopamine has previously been linked to feeding behavior.

The researchers found that lowering Dpp levels in muscle led to higher levels of dopamine in the brain and increased feeding. Conversely flies with higher Dpp levels in muscle had lower levels of brain dopamine and were less likely to seek food. The researchers also found that modulation of dopamine synthesis in the brain is key to the regulation of feeding by muscle-derived Dpp.

"Dpp is doing more than anyone thought it was. Beyond feeding behavior, endocrine Dpp signaling could be regulating a number of other tissue and systemic functions, including disease processes that involve dopaminergic neurons, " Demontis said. "And because Dpp has comparable proteins in humans, it may be relevant to feeding behavior and metabolic diseases in higher organisms."

(SACRAMENTO) -- Stronger comprehensive background check (CBC) policies enacted 2014 in Washington and 2015 in Oregon require private gun sellers to conduct background checks before selling firearms.

But have these newly enacted laws resulted in more background checks for private-party sales - the major source of guns for persons who commit crimes and are prohibited from owning them?

A study by the UC Davis Violence Prevention Research Program (VPRP) published Nov. 27 in Injury Epidemiology assessed changes in rates of background checks in Washington and Oregon from January 1999 through December 2018. They tracked monthly counts from the Federal Bureau of Investigation's National Instant Criminal Background Check System and compared them with synthetic controls created from 28 states that did not implement CBC policies during the study period.

The researchers found CBC policies were associated with an 18% increase in pre-firearm-sale checks in Oregon and a 4% increase in Washington state. They attribute the different rates between the two states to variation in the proportion of private party firearm sales, compliance with the new law among private gun sellers and the lack of mechanisms to measure enforcement of the laws.

"Washington's increase in private-party checks after its CBS policy took effect suggests a gradual adaptation to the new law by private gun sellers," said Alvaro Castillo-Carniglia, first author of the study who conducted the research as a VPRP scholar. "But firearm transactions coded as 'private' accounted for less than 5% of total background checks in the state, which is a very small proportion compared to national estimates."

In states without CBC policies, approximately 57% of private party transfers occur without background checks. In states with CBC policies, these private party transfers without checks decrease to 26%.

To fully determine the effects of CBC policies, the authors say they need more data and to assess changes in rates over a longer period of time.

Philadelphia, December 12, 2019 - High blood pressure in the lungs, known as pulmonary arterial hypertension (PAH), is a potentially fatal disease caused by obstruction of blood flow in the lungs. A new study in The American Journal of Pathology, published by Elsevier, sheds light on the pathology underlying PAH and shows that dofetilide, an FDA-approved KV11.1 channel blocker for the treatment of cardiac arrhythmias (brand name: Tikosyn), may be used for treatment of PAH.

Kv11.1 potassium selective channels are recognized for their function in the heart. Despite the importance of Kv11.1 channels for many physiological processes, their expression and function in pulmonary vasculature and potential role in PAH- and chronic obstructive pulmonary disease (COPD)-associated vascular remodeling had not been investigated.

Investigators examined lung tissue from patients with COPD and rats with experimentally-induced PAH. "Our study suggests that Kv11.1 channel blockers may have therapeutic potential for treatment of PAH. Specifically, we have shown that dofetilide, which is already FDA-approved as an antiarrhythmic and therefore has passed all of the drug safety requirements, can be considered for repurposing for treatment of patients with PAH," explained Tinatin I. Brelidze, PhD, assistant professor of pharmacology in the Department of Pharmacology and Physiology at Georgetown University Medical Center, Washington, DC, USA.

Researchers observed that Kv11.1 potassium selective channels are expressed in lungs and blocking these channels with dofetilide inhibits PAH associated with vascular remodeling. In control rats, Kv11.1 channels were expressed in the smooth muscle cell (SMC) layer of large diameter pulmonary arteries (PAs), but not in the SMCs of small diameter PAs (less than 100 μm). In rats with experimentally-induced PAH, the expression of Kv11.1 channels increased and the channels were found in both small and large PAs. The PA walls thickened as they became more muscular, and the lumens shrank.

When rats with PAH were treated with dofetilide, there was no evidence of the typical pathological changes in the vasculature associated with PAH. Dofetilide increased lumen diameter and decreased PA wall thickness to levels seen in the control rats without PAH.

In healthy human lung tissue, Kv11.1 channels were present only in the walls of large-diameter PAs. Lung tissue from patients with COPD showed collapse of alveoli, mild edema of the arterial walls, and fibrosis and thickening of PA walls. Kv11.1 channels were found in the walls of both large and small PAs, similar to that reported in rats with PAH.

Kv11.1 potassium channels are voltage-activated potassium channels that are expressed in many tissues and organs of the body. In the heart, Kv11.1 potassium channels help to repolarize cardiac action potentials to maintain proper heart rhythm whereas, in the brain, Kv11.1 channels regulate neuronal excitability. Inhibition of Kv11.1 channels also likely decreases the proliferation of cancer cells. "We hypothesize that similar to cancer, enlargement of SMCs in PAH is associated with the overexpression of Kv11.1 channels," noted Dr. Brelidze.

Since there is extensive clinical experience with dofetilide for cardiac arrhythmias and it has passed all drug safety requirements, the investigators suggest it merits consideration as a potential treatment for patients with PAH.

The process of building a tiny cube has revealed some of the fundamental mysteries of how molecules bind together in natural environments. Researchers hope to apply this knowledge to future projects designing complex structures that can mimic life.

When two molecules surrounded by water move towards each other, part of their initial attraction is sometimes due to the chemical force to repel water -- the hydrophobic effect.

Once the molecules are near each other, but not yet formally bound, a much weaker force becomes important -- the dispersion force.

"Our dream is to control the dispersion force and provide a simple design principle to use the dispersion force to build complex self-assembling structures," said Professor Shuichi Hiraoka, leader of the laboratory where the research was performed in the University of Tokyo Department of Basic Science.

Dispersion forces are one type of van der Waals forces, some of the weakest chemical interactions known in nature. Although weak, van der Waals forces are important; they help geckos walk up walls and were previously identified in 2018 by the same research group as locking together the gear- or snowflake-shaped molecules of the self-assembling nanocubes.

Measuring the dispersion force under natural conditions, such as when molecules are in solution with water, has been impossible. The force is so weak it cannot be identified separately from the other forces at play.

However, in new experiments, the research team used their self-assembling nanocubes as tools to amplify differences in the dispersion force.

The molecules that make up the sides of the cubes were modified to contain atoms selected for their polarizability, meaning their responsiveness to the surrounding electric field. Each fully assembled nanocube contained 18 of those polarizable atoms.

The combined effect of 18 atoms was enough to create measurable differences in the dispersion force depending on which polarizable atom was attached.

The dispersion force is calculated mathematically after using a technique called isothermal titration calorimetry to measure the amount of heat released when molecules bind together.

More polarizable atoms created stronger dispersion forces and made the nanocubes more stable. Depending on the estimated value of the hydrophobic effect, the dispersion force contributes 0.6 to 2.2 times greater attractive force and stability to the cube than the hydrophobic effect.

Researchers plan to use this knowledge about more polarizable atoms creating stronger dispersion forces to design future artificial molecular structures with more complex shapes and increased functions.

"For example, we could design molecules with larger binding surface areas and place polar atoms along the edges to enhance overall stability through the attraction of dispersion forces," said Hiraoka.

Solving a mystery in drug design

Hiraoka states that the measurements for nanocubes built with normal hydrogen compared to deuterium, the "heavy" isotope of hydrogen, should be relevant to drug design theory. Research by other groups had led to conflicting reports among chemists on whether swapping hydrogen with the twice-as-heavy and larger deuterium would create stronger dispersion force.

As a general rule, larger atoms are more polarizable and researchers had new data indicating increased polarizability led to stronger dispersion forces. However, in some cases the smaller hydrogen actually makes a stronger dispersion force than heavy deuterium, but other reports showed the opposite or negligibly small difference between the two atoms.

"In our experiments, the entropy-enthalpy difference is completely balanced. The free energy released by nanocubes with hydrogen or deuterium is essentially identical, so there may be no difference between them," said Hiraoka.

An essential difference between previous research and these experiments is that the UTokyo team used a more lifelike condition of being in solution with water and amplified the effect using the nanocube design.

Nurses sleep nearly an hour and a half less before work days compared to days off, which hurts patient care and safety, finds a new study by researchers at NYU Rory Meyers College of Nursing. The findings are published in Sleep Health, the journal of the National Sleep Foundation.

"Nurses are sleeping, on average, less than recommended amounts prior to work, which may have an impact on their health and performance on the job," said Amy Witkoski Stimpfel, PhD, RN, assistant professor at NYU Rory Meyers College of Nursing and the study's lead author.

Nursing, especially in hospitals, is dominated by shift work, with nurses working outside of the traditional 9-to-5 day in order to be at the bedside around the clock. Research shows that shift work takes a toll on circadian rhythms and can impair the performance of workers.

In addition, 12-hour shifts are common and often result in unexpected overtime to finish patient care tasks or charting. Taken together with commute times and domestic responsibilities, nurses often have limited time to sleep before or between shifts.

Sleep deprivation hurts workers' ability to handle complex and stressful tasks, and work-related sleep loss has led to serious errors in other industries, with the nuclear meltdown at Chernobyl as a particularly devastating example. In healthcare, fatigued nurses may be a risk for making critical mistakes in administering medication or making clinical decisions.

In order to better understand nurses' sleep behaviors and patient outcomes, Witkoski Stimpfel and her colleagues studied sleep duration and work characteristics among registered nurses to determine whether sleep duration influences quality of care and patient safety. The researchers used data from two surveys of 1,568 nurses collected in 2015 and 2016.

The nurses were asked how much sleep they usually get, including naps, in the 24 hours prior to a scheduled shift, as well as how much sleep they usually get when they are not scheduled to work. They were also asked about the quality of patient care in their workplace. Patient safety was measured using the Agency for Healthcare Research and Quality (AHRQ) Hospital Survey on Patient Safety Culture.

Nurses reported getting, on average, just under 7 hours (414 minutes) of sleep prior to a work day and more than 8 hours (497 minutes) prior to a non-work day. Thus, the difference in sleep duration between work and non-work days was 83 minutes, or nearly an hour and a half less sleep before a work shift.

In addition, getting less sleep was associated with lower measures of patient safety and quality of care, a finding that may indicate several underlying issues. At the individual level, nurses who are sleeping less may be more fatigued at work, which may result in performance impairments. At the organizational level, if nurses are working in an environment that has frequent staffing shortages or high turnover resulting in unexpected overtime and long hours, patient safety may be compromised in part by tired, overworked nurses.

Can nurses "catch up" on sleep between shifts? Witkoski Stimpfel said it is unlikely.

"Research on chronic partial sleep deprivation in healthy adults shows that after several days of not getting enough sleep, more than one day of 'recovery sleep'--or more than 10 hours in bed--may be needed to return to baseline functioning. But considering a nurse's schedule, which often involves consecutive 12-hour shifts and may only offer one or two days off between shifts, the risk of complete recovery, or 'catching up,' is low," noted Witkoski Stimpfel.

The researchers note that more research on nurses' sleep is needed, but in the interim, healthcare leaders can use evidence-based scheduling strategies, limit the use of overtime, and provide professional development on the importance of sleep for nurses.

"It is in everyone's interest to have nurses well-rested so they can perform their critical function within the healthcare system and keep patients safe," said Christine Kovner, PhD, RN, FAAN, Mathey Mezey Professor of Geriatric Nursing at NYU Meyers and the study's coauthor.

New research will be live in npj Digital Medicine on December 12, 2019, that will feature a machine learning app aimed at preventing patients from severe fall-related injuries and death.

This AI technology was developed by Houston Methodist and tested over an eight-month period to help address the growing concern of severe patient falls with seniors and the worry it causes their care-providers and care-givers.

HOW IT WORKS

The AI app predicts the risk of getting injured when a patient falls. Clinical parameters and patient demographics such as bone density, diagnosis, past procedures, etc. are used to populate the app so it then triggers tailored interventions to prevent these high-risk severe injury patients from falling - whether they are in the hospital setting or with home caregivers. This AI technology can be integrated into the patient's electronic medical record (EMR) and make things easier for clinicians since it will be part of the record and will automatically flag or alert the care-providers for high risk fall with harm patients when they enroll in the hospital. This will then trigger a prevention-focused intervention plan or clinical care path. The immediate benefit to the patient is to avoid falling and injuries or even death. The benefit for the hospital is that additional costs and/or lawsuits for these types of patients can be avoided.

THE NEED

In 2015, the estimated medical costs attributable to fatal and nonfatal falls was approximately $50.0 billion. For nonfatal falls, Medicare paid approximately $28.9 billion, Medicaid $8.7 billion, and private and other payers $12.0 billion. Overall medical spending for fatal falls was estimated to be $754 million.

NEW RESEARCH & EXPERT AVAILABILITY

The manuscript titled, "Preventing Inpatient Falls with Injuries using Integrative Machine Learning Prediction: A Cohort Study," will be available for full review soon, and I'll follow-up with a link. I just wanted to get this on your radar and see if you might be interested in learning more about this new AI app and research. I'd be happy to connect you to Dr. Stephen Wong, who spearheaded the study and can speak to the increased need for technology like this for clinicians and caregivers to help patients at risk for severe falls.