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MAYWOOD, IL--Vestibular schwannomas, more commonly known as acoustic neuromas, are benign brain tumors that develop on the balance (vestibular) and hearing or auditory nerves leading from the inner ear to the brain. These tumors are rare in children, and as a result, there is little consensus on common symptoms, tumor size, treatment, outcomes and recurrence rates for acoustic neuroma in pediatric patients.

In a new study, "Pediatric vestibular schwannomas: case series and a systematic review with meta-analysis," appearing in the Journal of Neurosurgery, researchers at Loyola University Medical Center and Loyola University Chicago Stritch School of Medicine performed a retrospective review of the diagnosis, treatment and outcomes of 15 patients (21 years of age or younger) with unilateral vestibular schwannomas, without neurofibromatosis type 2 (a genetic disorder that causes noncancerous tumor growth in the nervous system), who underwent surgery at Loyola University Medical Center between 1997 and 2019. The study authors also reviewed existing literature on this type of tumor in pediatric patients.

Overall, the review found that pediatric patients had similar symptoms to those of adult patients with acoustic neuromas; however, the tumor size was typically larger in the pediatric patients at the time of diagnosis, and symptoms of mass effect (secondary effects caused by the tumor) were more common. While some children with small tumors can be successfully treated with surgery only, residual tumors in pediatric patients were found to have a higher rate of regrowth than those in adults.

"This research provides a valuable baseline from which to assess and treat future pediatric patients presenting with symptoms associated with acoustic neuromas," said lead study author Douglas E. Anderson, MD, chair, Loyola Medicine and Loyola University Chicago Stritch School Department of Neurological Surgery. "Because of the tumor size in children at presentation, appropriate treatments should reflect the risk for tumor regrowth."

The study identified common symptoms in pediatric acoustic neuroma patients: hearing loss in 87% of patients; headache, 40%; vertigo, 33%; ataxia (degenerative disease of the nervous system), 33%; and tinnitus (ringing in the ear), 33%. At the time of surgery, the mean tumor size was 3.3 centimeters, with four patients presenting with 1-centimeter tumors. Four patients had residual tumor mass left following surgery, with three (75%) having significant regrowth requiring further treatment. The literature review identified another 81 patients from 26 studies, with an average age of 12.1 (range 6-21) and an average tumor size of 4.1 centimeters.

Good health and a happy outlook on life may seem like equally worthy yet independent goals. A growing body of research, however, bolsters the case that a happy outlook can have a very real impact on your physical well-being.

New research published in the journal Psychological Science shows that both online and in-person psychological interventions--tactics specifically designed to boost subjective well-being--have positive effects on self-reported physical health. The online and in-person interventions were equally effective.

"Though prior studies have shown that happier people tend to have better cardiovascular health and immune-system responses than their less happy counterparts," said Kostadin Kushlev, a professor in Georgetown University's Department of Psychology and one of the authors of the paper, "our research is one of the first randomized controlled trials to suggest that increasing the psychological well-being even of generally healthy adults can have benefits to their physical health."

Intervention for Healthy Outcomes

Over the course of six months, Kushlev and his colleagues at the University of Virginia and the University of British Columbia examined how improving the subjective well-being of people who were not hospitalized or otherwise undergoing medical treatment affected their physical health.

A group of 155 adults between the ages of 25 and 75 were randomly assigned either to a wait-list control condition or a 12-week positive psychological intervention that addressed three different sources of happiness: the "Core Self," the "Experiential Self," and the "Social Self."

The first 3 weeks of the program focused on the Core Self, helping individuals identify their personal values, strengths, and goals. The next 5 weeks focused on the Experiential Self, covering emotion regulation and mindfulness. This phase also gave participants tools to identify maladaptive patterns of thinking. The final 4 weeks of the program addressed the Social Self, teaching techniques to cultivate gratitude, foster positive social interactions, and engage more with their community.

The program, called Enduring Happiness and Continued Self-Enhancement (ENHANCE), consisted of weekly modules either led by a trained clinician or completed individually using a customized online platform. None of the modules focused on promoting physical health or health behaviors, such as sleep, exercise, or diet.

Each module featured an hour-long lesson with information and exercises; a weekly writing assignment, such as journaling; and an active behavioral component, such as guided meditation.

"All of the activities were evidence-based tools to increase subjective well-being," Kushlev noted.

When the program concluded, the participants were given individual evaluations and recommendations of which modules would be most effective at improving their happiness in the long term. Three months after the conclusion of the trial, researchers followed up with the participants to evaluate their well-being and health.

A Happy Future

Participants who received the intervention reported increasing levels of subjective well-being over the course of the 12-week program. They also reported fewer sick days than control participants throughout the program and 3 months after it ended.

The online mode of administering the program was shown to be as effective as the in-person mode led by trained facilitators.

"These results speak to the potential of such interventions to be scaled in ways that reach more people in environments such as college campuses to help increase happiness and promote better mental health among students," Kushlev said.

HANOVER, N.H. - July 22, 2020 - A citizen science program that began over a decade ago has confirmed the use of dragonflies to measure mercury pollution, according to a study in Environmental Science & Technology.

The national research effort, which grew from a regional project to collect dragonfly larvae, found that the young form of the insect predator can be used as a "biosentinel" to indicate the amount of mercury that is present in fish, amphibians and birds.

The finding will make it easier to conduct mercury research and could lead to a national registry of pollution data on the toxic metal.

"Researchers needed a proxy for fish since that is what people and animals eat," said Celia Chen, director of Dartmouth's Toxic Metals Superfund Research Program and a co-author of the study. "Fish can be hard to work with for a national-level research program, so it's helpful to be able to focus our research on dragonfly larvae."

Dragonflies occupy diverse freshwater habitats across six continents and have tissues that take up mercury in its toxic form. As predators, dragonflies operate in the food web in a manner that is similar to fish, birds and amphibians that also accumulate mercury in their body tissues.

The study includes data from thousands of larval dragonfly specimens collected from nearly 500 locations across 100 sites within the U.S. National Park System. The survey was collected from 2009 through 2018 as part of the national Dragonfly Mercury Project.

"The support of citizen scientists around the country created the opportunity for this study to have such significance. This is a terrific example of how public outreach around science can bring results that help the entire country," said Chen.

Methylmercury, the organic form of the toxic metal mercury, poses risks to humans and wildlife through the consumption of fish. Mercury pollution comes from power plants, mining and other industrial sites. It is transported in the atmosphere and then deposited in the natural environment, where wildlife can be exposed to it.

Fish and aquatic birds are commonly used to monitor mercury levels but are difficult to work with in a large-scale project because of their size, migratory patterns, and the diversity of species. Dragonfly larvae are easy to collect and make the citizen science research project possible.

"It is extremely rewarding to assist teachers and their students to engage in data-driven, real-world research impacting their communities. I see a lot of enthusiasm from students eager to take part in 'real' science," said Kate Buckman, a research scientist who serves as Dartmouth's coordinator for the citizen science program.

As part of the decade-long study, researchers came up with the first-ever survey of mercury pollution in the U.S. National Park System. The research found that about two-thirds of the aquatic sites studied within the national parks are polluted with moderate-to-extreme levels of mercury.

The finding of mercury within park sites is not an indicator that the source of pollution is in the parks themselves. Mercury is distributed widely within the atmosphere and is deposited in the protected areas as it is in other water bodies across the country.

Given that the parks studied stretch across the entire U.S., including Alaska and Hawaii, the findings reflect levels of mercury throughout the country.

"To date, we have not conducted such a broad scale survey on mercury in the U.S. The beauty of the dragonfly data set is that it is national, covers a huge area with different systems, and has the potential to create a national baseline of mercury pollution information," said Chen.

The study also found that faster moving bodies of water, such as rivers and streams, featured more mercury pollution than slower moving systems including lakes, ponds, and wetlands.

According to the paper: "Collectively, this continental-scale study demonstrates the utility of dragonfly larvae for estimating the potential mercury risk to fish and wildlife in aquatic ecosystems and provides a framework for engaging citizen science as a component of landscape [mercury] monitoring programs."

In the citizen science project, students and park visitors conduct field studies and collect the dragonfly specimens. National Park rangers help guide the citizen scientists through the protected sites.

The original project was launched by Dr. Sarah Nelson at the University of Maine and the Schoodic Institute in 2007. Dartmouth's Toxic Metals Superfund Research Program developed a regional effort in New Hampshire and Vermont in 2010. The project was expanded nationally by the National Park Service and the U.S. Geological Survey.

The citizen science project in the Upper Valley region of New England typically runs in the fall with participation from high school students in New Hampshire and Vermont.

Researchers from the USGS, National Park Service, University of Maine, Appalachian Mountain Club and Dartmouth participated in this study. Collin Eagles-Smith from the USGS served as the paper's lead author. Sarah Nelson who launched the original project is now director of research at the Appalachian Mountain Club.

Spectroscopy is the use of light to analyze physical objects and biological samples. Different kinds of light can provide different kinds of information. Vacuum ultraviolet light is useful as it can aid people in a broad range of research fields, but generation of that light has been difficult and expensive. Researchers created a new device to efficiently generate this special kind of light using an ultrathin film with nanoscale perforations.

The wavelengths of light you see with your eyes constitute a mere fraction of the possible wavelengths of light that exist. There's infrared light which you can feel in the form of heat, or see if you happen to be a snake, that has a longer wavelength than visible light. At the opposite end is ultraviolet (UV) light which you can use to produce vitamin D in your skin, or see if you happen to be a bee. These and other forms of light have many uses in science.

Within the UV range is a subset of wavelengths known as vacuum ultraviolet light (VUV), so called because they are easily absorbed by air but can pass through a vacuum. Some VUV wavelengths in the region of around 120-200 nanometers are of particular use to scientists and medical researchers as they can be used for chemical and physical analyses of different materials and even biological samples.

However, there is more to light than a wavelength. For VUV to be truly useful, it also needs to be twisted or polarized in a manner called circular polarization. Existing methods to produce VUV, such as using particle accelerators or laser-driven plasmas, have many drawbacks, including cost, scale and complexity. But also, these can only produce untwisted linear polarized VUV. If there was a simple way to make circular polarized VUV, it would be extremely beneficial. Assistant Professor Kuniaki Konishi from the Institute for Photon Science and Technology at the University of Tokyo and his team may just have the answer.

"We have created a simple device to convert circularly polarized visible laser light into circularly polarized VUV, twisted in the opposite direction," said Konishi. "Our photonic crystal dielectric nanomembrane (PCN) consists of a sheet made from an aluminium oxide-based crystal (?-Al2O3) only 48 nm thick. It sits atop a 525 micrometer-thick sheet of silicon which has 190 nm-wide holes cut into it 600 nm apart."

To our eyes the PCN membrane just looks like a flat featureless surface, but under a powerful microscope the pattern of perforations can be seen. It looks a little like the holes in a showerhead which increase the water pressure to make jets.

"When pulses of circularly polarized blue laser light with a wavelength of 470 nm shine down these channels in the silicon, the PCN acts on these pulses and twists them in the opposing direction," said Konishi. "It also shrinks their wavelengths to 157 nm which is well within the range of VUV that is so useful in spectroscopy."

With short pulses of circularly polarized VUV, researchers can observe fast or short-lived physical phenomena at the submicrometer scale that are otherwise impossible to see. Such phenomena include the behaviors of electrons or biomolecules. So this new method to generate VUV can be useful to researchers in medicine, life sciences, molecular chemistry and solid state physics. Although a similar method has been demonstrated before, it produced less useful longer wavelengths, and did so using a metal-based film which is subject to rapid degradation in the presence of laser light. PCN is far more robust to this.

"I am pleased that through our study of PCN, we found a new and useful application for circularly polarized light conversion, generating VUV with the intensity required to make it ideal for spectroscopy," said Konishi. "And it was surprising that the PCN membrane could survive the repeated bombardment of laser light, unlike previous metal-based devices. This makes it suitable for lab use where it may be used extensively over long periods. We did this for basic science and I hope to see many kinds of researchers make good use of our work."

Abstract

The National Institute of Information and Communications Technology (NICT), the Japan Science and Technology Agency (JST), Toin University of Yokohama, and Chiba University have succeeded in developing a color-multiplexed holography system by which 3D information of objects illuminated by a white-light lamp and self-luminous specimens are recorded as a single multicolor hologram by a specially designed and developed monochrome image sensor. Single-shot color-multiplexed fluorescence holographic microscopy is realized by exploiting digital holography and computational coherent superposition (CCS), with the latter having been proposed by NICT. The developed microscope acquires the color 3D information of self-luminous objects with a single-shot exposure and no color filter array. The developed system does not need a laser light source and has the capability to conduct multicolor 3D motion-picture sensing of biological samples and moving objects at video rate. Further development will be conducted toward multicolor 3D microscopy of extremely weak light such as autofluorescence light and nonlinear light.

This achievement was published in Applied Physics Letters as an open-access paper on July 22, 2020.

Achievements

Simultaneous color 3D sensing of multiple self-luminous objects was demonstrated by recording a single color-multiplexed hologram of fluorescence light. Multicolor 3D imaging with a white-light lamp was also demonstrated with a single-hologram recording. CCS, which is a holographic multiplexing technique, was exploited to record a color-multiplexed hologram on a monochrome image sensor without any color filter. Only a single-shot exposure is required to conduct color fluorescence holographic 3D sensing using the developed system. The number of exposures required to acquire the information is less than 1/250 of that required for a conventional color-multiplexed fluorescence holographic microscope.

The developed system will be useful for applications to high-speed multicolor holographic 3D motion-picture microscopy for spatially and temporally incoherent light and multicolor holographic 3D image sensing of ultimately weak light such as autofluorescence light, nonlinear light including spontaneous Raman scattering light, chemically activated light, and natural light.

Future prospects

Increasing the recording speed in holographic multidimensional sensing of ultimately weak self-luminous light sources

Applications to multicolor holographic 3D motion-picture image sensing for spatially incoherent light

A joint research team from the Korea Institute of Science and Technology (KIST), led by Dr. Kyung-guen Song from the KIST Water Cycle Research Center and Dr. Won-jun Choi from the KIST Center for Opto-Electronic Materials and Devices, announced that it had used solar heat, a source of renewable energy, to develop a highly efficient membrane distillation technology that can produce drinking water from seawater or wastewater.

Membrane distillation is a desalination technology that turns seawater into potable water. In this process, water vapor is evaporated from seawater by thermal energy and passed through a *hydrophobic membrane, which separates the water vapor from the seawater. The water vapor then condensates to produce drinking water. Compared to existing thermal desalination methods, membrane distillation can be performed at low temperatures, which means it requires less energy, and therefore, it is receiving attention as a next-generation desalination technology. Solar-driven membrane distillation technology, in particular, has been receiving much attention, as it uses solar heat, a form of renewable energy, as its heat source, thereby helping to prevent global warming by reducing the use of fossil fuels.

*Hydrophobic membrane: A separating membrane used for distillation because of its low affinity with water, allowing only water vapor to pass through

The most important part of solar-driven membrane distillation is the solar absorber, which is used to gather solar light and heat up water. Previously commercialized solar absorbers have low solar absorption performance and can only be used in certain areas with the proper solar radiation conditions. Another weakness of preexisting systems is that their solar absorber must be very large in size in order to properly absorb the necessary amount of solar radiation.

The KIST research team applied a new solar absorber using titanium (Ti) and magnesium fluoride (MgF2) to develop a high-efficient solar driven membrane distillation technology that can exponentially increase water production.

The newly developed solar absorber absorbs over 85% of solar energy with a wavelength of 0.3-2.5 μm, which is the main spectrum of solar energy, while being able to heat water to temperatures of more than 80°C. Furthermore, when the absorber was applied to a solar-driven membrane distillation, it was possible to produce 4.78 L/m2 of potable water over a period of 10 hours on a clear day in September. This demonstrates a very high level of performance and a production volume of more than double that of previously commercialized solar absorbers.

** Based on the annual average global insolation of Seoul ( 3.23 kWh/m2/day): An existing solar heat absorber with an area of 1m2, produced 2.14 L of water / A solar heat absorber of the same area, newly developed by the KIST, produced 4.49 L of water over the same time period.

The new solar absorber uses a multi-layer film made of titanium (Ti) metal and magnesium fluoride (MgF2) that can be simply fabricated using an electro-beam evaporator. Since the new solar absorber has excellent solar absorption performance, it is possible to apply it not only to solar-driven membrane distillation, but also to solar boilers and other apparatuses.

The solar-driven membrane distillation technology that the research team developed using the new solar absorber uses solar as its heat source. As such, the technology can be used to supply drinking water in isolated areas without energy infrastructure such as underdeveloped countries, island areas, and remote areas with a lack of potable water. The technology is also expected to be used by the military to supply drinking water to soldiers stationed abroad or at army field posts.

"This study combines material technologies with water treatment technologies and is significant in that it is a successful case of integrated research that has resulted in revolutionary achievements," said Dr. Kyung-guen Song of the KIST. "We plan to continue developing water treatment technologies that apply advanced materials technologies through ongoing integrated research."

WEST LAFAYETTE, Ind. - An invention may turn one of the most widely used materials for biomedical applications into wearable devices to help monitor heart health.

A team from Purdue University developed self-powered wearable triboelectric nanogenerators (TENGs) with polyvinyl alcohol (PVA)-based contact layers for monitoring cardiovascular health. TENGs help conserve mechanical energy and turn it into power.

The Purdue team's work is published in the journal Advanced Materials.

"The PVA-based TENGs show great potential for self-powered biomedical devices and open doors to new technologies that use widely deployed biocompatible materials for economically feasible and ecologically friendly production of functional devices in energy, electronics and sensor applications," said Wenzhuo Wu, the Ravi and Eleanor Talwar Rising Star Assistant Professor of industrial engineering in Purdue's College of Engineering, who led the development team. "We transform PVA, one of the most widely used polymers for biomedical applications, into wearable, self-powered triboelectric devices which can detect the imperceptible degree of skin deformation induced by human pulse and capture the cardiovascular information encoded in the pulse signals with high fidelity."

Cardiovascular health is typically measured by echocardiogram to measure electrical activity in the heart or photoplethysmography that measures changes in blood volume in the peripheral microvasculature.

"These technologies can often be invasive to patients and have not yet been adapted into wearables for personalized on-demand monitoring," Wu said. "TENGs with PVA blend contact layers produce fast readout with distinct peaks for blood ejection, blood reflection in the lower body, and blood rejection from the closed aortic valve, which may enable detection of common cardiovascular diseases such as cardiovascular disease, coronary artery disease and ischemic heart disease."

Wu said PVA offers a valuable opportunity as potential constituents in future wearable self-powered devices. The PVA-based triboelectric devices can harvest the mechanical energy from the human body and use such electric power to support the operations of other biomedical devices.

Wu said the PVA-based triboelectric devices can function as self-powered sensors to detect and monitor the mechanical activities from the human body in applications such as health monitoring, human-machine interface, teleoperated robotics, consumer electronics and virtual and augmented technologies.

BLOOMINGTON, Ind. -- Despite efforts by ridesharing companies to eliminate or reduce discrimination, research from the Indiana University Kelley School of Business finds that racial and LGBT bias persists among drivers.

Platforms such as Uber, Lyft and Via responded to drivers' biased behavior by removing information that could indicate a rider's gender and race from initial ride requests. However, researchers still found that biases against underrepresented groups and those who indicate support for the LGBT community continued to exist after drivers accepted a ride request -- when the rider's picture would then be displayed.

In other words, their efforts shifted some of the biased behavior until after the ride was confirmed, resulting in higher cancellation rates. Understanding whether bias has been removed also is important for ridesharing companies as they not only compete against each other but also with traditional transportation options.

"Our results confirm that bias at the ride request stage has been removed. However, after ride acceptance, racial and LGBT biases are persistent, while we found no evidence of gender biases," said Jorge Mejia, assistant professor of operations and decision technologies. "We show that signaling support for a social cause -- in our case, the lesbian, gay, bisexual and transgender community -- can also impact service provision. Riders who show support for the LGBT community, regardless of race or gender, also experience significantly higher cancelation rates."

Mejia and co-author Chris Parker, assistant professor in the information technology and analytics department at American University in Washington, believe they are the first to use support for social causes as a bias-enabling characteristic. Their article, "When Transparency Fails: Bias and Financial Incentives in Ridesharing Platforms," is published in Management Science.

They performed a field experiment on a ridesharing platform in fall 2018 in Washington, D.C. They randomly manipulated rider names, using those traditionally perceived to be white or Black, as well as profile pictures to observe drivers' behavior patterns in accepting and canceling rides. To illustrate support for LGBT rights, the authors overlaid a rainbow filter on the rider's picture profile.

"We found that underrepresented minorities are more than twice as likely to have a ride canceled than Caucasians; that's about 3 percent versus 8 percent," Mejia said. "There was no evidence of gender bias."
Mejia and Parker also varied times of ride requests to study whether peak price periods affected bias. They found that higher prices associated with peak times alleviated some of the bias against riders from the underrepresented group, but not against those who signal support for the LGBT community.

They believe that ridesharing companies should use other data-driven solutions to take note of rider characteristics when a driver cancels and penalize the driver for biased behavior. One possible way to punish drivers is to move them down the priority list when they exhibit biased cancelation behavior, so they have fewer ride requests. Alternatively, less-punitive measures may provide "badges" for drivers who exhibit especially low cancelation rates for minority riders.

But, ultimately, policymakers may need to intervene, Mejia said.

"Investments in reducing bias may not occur organically, as ridesharing platforms are trying to maximize the number of participants in the platform -- they want to attract both riders and drivers," he said. "As a result, it may be necessary for policymakers to mandate what information can be provided to a driver to ensure an unbiased experience, while maintaining the safety of everyone involved, or to create policies that require ridesharing platforms to monitor and remove drivers based on biased behavior.

"Careful attention should be paid to these policies both before and after implementation, as unintended consequences are almost sure to follow any simple fix."

IU Research

IU's world-class researchers have driven innovation and creative initiatives that matter for 200 years. From curing testicular cancer to collaborating with NASA to search for life on Mars, IU has earned its reputation as a world-class research institution. Supported by $680 million last year from our partners, IU researchers are building collaborations and uncovering new solutions that improve lives in Indiana and around the globe.

Post-surgical bleeding is associated with more deaths than blood clots from surgery, according to a Vanderbilt University Medical Center study published in the journal Anesthesia & Analgesia.

Researchers used nearly 15 years of data on millions of patients from the American College of Surgeons' National Surgical Quality Improvement Program database, and some very advanced computer techniques, to do a direct comparison of bleeding versus clotting after surgery for patients in the U.S.

"We wanted to do a head-to-head comparison of those two in a large surgical population and look at the tradeoff in terms of mortality. We found, in every single year, a consistent signal for bleeding," said senior author Robert Freundlich, MD, assistant professor of Anesthesiology and Biomedical Informatics at Vanderbilt University Medical Center.

"Bleeding had very, very high attributable mortality, meaning death that you could say statistically was related to the occurrence of bleeding. Whereas, in every single year, we didn't see that same signal for blood clots," he said.

The America College of Surgeons tracks bleeding for the first 72 hours after surgery in their database whereas blood clots are tracked for up to 30 days after surgery. Most bleeding related to the surgery itself is generally early, in the first three days, whereas blood clots, even if they are related to the surgery itself, can takes weeks or up to a month to occur.

"Clinically we often think of bleeding and blood clots as competing interests so a lot of the things that we do to decrease bleeding can increase the risk of blood clots," Freundlich said. "And, conversely, a lot of the things that we do to treat blood clots can increase the risk of bleeding.

Adjustments were made for patients' baseline risk of dying after surgery, what procedure they were having, and for other complications which may have happened after surgery.

Freundlich and first author Melissa Bellomy, MD, clinical fellow, Division of Cardiothoracic Anesthesiology, noted that clotting has been studied very intensely in recent years, with a number of large national groups putting out recommendations for how best to treat and prevent blood clots after surgery.

"I think people are doing a really good job of addressing blood clots after surgery, making sure that even when blood clots do happen they aren't bad enough to lead to a patient dying," Freundlich said. "And I would like to think that current medical therapy is probably working well, which is what we see in the database. Really just very, very undetectable mortality."

But bleeding remains a very concerning complication after surgery, based on the what he and colleagues found in the database.

"The mortality attributable to bleeding in the time period around surgery was significantly higher than from blood clots in every year that we studied," Bellomy said. "This raises the important questions of why bleeding is associated with more death and how can we best treat patients to prevent death associated with bleeding."

Treatments depend on the source of the bleeding but can include going back and re-exploring or revising the initial surgery, giving blood products to help prevent bleeding, and pharmacologic therapies used to try to prevent bleeding after surgery.

"What is most important is having a team of expert providers who know when they need to be very aggressive in treating these post-operative complications, particularly with bleeding," Freundlich said.

As the Covid-19 shutdowns and stay-at-home orders brought much of the world's travel and commerce to a standstill, people around the world started noticing clearer skies as a result of lower levels of air pollution. Now, researchers have been able to demonstrate that those clearer skies had a measurable impact on the output from solar photovoltaic panels, leading to a more than 8 percent increase in the power output from installations in Delhi.

While such an improved output was not unexpected, the researchers say this is the first study to demonstrate and quantify the impact of the reduced air pollution on solar output. The effect should apply to solar installations worldwide, but would normally be very difficult to measure against a background of natural variations in solar panel output caused by everything from clouds to dust on the panels. The extraordinary conditions triggered by the pandemic, with its sudden cessation of normal activities, combined with high-quality air-pollution data from one of the world's smoggiest cities, afforded the opportunity to harness data from an unprecedented, unplanned natural experiment.

The findings are reported in the journal Joule, in a paper by MIT professor of mechanical engineering Tonio Buonassisi, research scientist Ian Marius Peters, and three others in Singapore and Germany.

The study was an extension of previous research the team has been conducting in Delhi for several years. The impetus for the work came after an unusual weather pattern in 2013 swept a concentrated plume of smoke from forest fires in Indonesia across a vast swath of Indonesia, Malaysia, and Singapore, where Peters, who had just arrived in the region, found "it was so bad that you couldn't see the buildings on the other side of the street."

Since he was already doing research on solar photovoltaics, Peters decided to investigate what effects the air pollution was having on solar panel output. The team had good long-term data on both solar panel output and solar insolation, gathered at the same time by monitoring stations set up adjacent to the solar installations. They saw that during the 18-day-long haze event, the performance of some types of solar panels decreased, while others stayed the same or increased slightly. That distinction proved useful in teasing apart the effects of pollution from other variables that could be at play, such as weather conditions.

Peters later learned that a high-quality, years-long record of actual measurements of fine particulate air pollution (particles less than 2.5 micrometers in size) had been collected every hour, year after year, at the U.S. Embassy in Delhi. That provided the necessary baseline for determining the actual effects of pollution on solar panel output; the researchers compared the air pollution data from the embassy with meteorological data on cloudiness and the solar irradiation data from the sensors.

They identified a roughly 10 percent overall reduction in output from the solar installations in Delhi because of pollution - enough to make a significant dent in the facilities' financial projections.

To see how the Covid-19 shutdowns had affected the situation, they were able to use the mathematical tools they had developed, along with the embassy's ongoing data collection, to see the impact of reductions in travel and factory operations. They compared the data from before and after India went into mandatory lockdown on March 24, and also compared this with data from the previous three years.

Pollution levels were down by about 50 percent after the shutdown, they found. As a result, the total output from the solar panels was increased by 8.3 percent in late March, and by 5.9 percent in April, they calculated.

"These deviations are much larger than the typical variations we have" within a year or from year to year, Peters says -- three to four times greater. "So we can't explain this with just fluctuations." The amount of difference, he says, is roughly the difference between the expected performance of a solar panel in Houston versus one in Toronto.

An 8 percent increase in output might not sound like much, Buonassisi says, but "the margins of profit are very small for these businesses." If a solar company was expecting to get a 2 percent profit margin out of their expected 100 percent panel output, and suddenly they are getting 108 percent output, that means their margin has increased fivefold, from 2 percent to 10 percent, he points out.

The findings provide real data on what can happen in the future as emissions are reduced globally, he says. "This is the first real quantitative evaluation where you almost have a switch that you can turn on and off for air pollution, and you can see the effect," he says. "You have an opportunity to baseline these models with and without air pollution."

By doing so, he says, "it gives a glimpse into a world with significantly less air pollution." It also demonstrates that the very act of increasing the usage of solar electricity, and thus displacing fossil-fuel generation that produces air pollution, makes those panels more efficient all the time.

Putting solar panels on one's house, he says, "is helping not only yourself, not only putting money in your pocket, but it's also helping everybody else out there who already has solar panels installed, as well as everyone else who will install them over the next 20 years." In a way, a rising tide of solar panels raises all solar panels.

Though the focus was on Delhi, because the effects there are so strong and easy to detect, this effect "is true anywhere where you have some kind of air pollution. If you reduce it, it will have beneficial consequences for solar panels," Peters says.

Even so, not every claim of such effects is necessarily real, he says, and the details do matter. For example, clearer skies were also noted across much of Europe as a result of the shutdowns, and some news reports described exceptional output levels from solar farms in Germany and in the U.K. But the researchers say that just turned out to be a coincidence.

"The air pollution levels in Germany and Great Britain are generally so low that most PV installations are not significantly affected by them," Peters says. After checking the data, what contributed most to those high levels of solar output this spring, he says, turned out to be just "extremely nice weather," which produced record numbers of sunlight hours.

An article published today in the Annals of Internal Medicine reports that 25 million dwellings that house 81 million Americans lack adequate space or plumbing to allow compliance with recommendations that a person who may have COVID-19 maintain physical separation from others in their household.

The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) advise those who are infected with or have been exposed to COVID-19 stay at home, confining themselves to a separate bedroom and bathroom if possible. Researchers from Case Western Reserve University and the City University of New York at Hunter College used data from the American Housing Survey to determine the feasibility of providing separate bedrooms and bathrooms in U.S. dwellings. They found that more than 1 in 5 homes -- housing about one quarter of all Americans -- lack sufficient space and plumbing facilities to comply with the WHO and CDC recommendations.

The proportion of homes unsuitable for isolation or quarantine is particularly high among minority and low-income households, which have experienced high rates of COVID-19 illness and death. About 46% of Latinx people, 43% of Native Americans, and 32% of Black Americans live in dwellings where separation is not feasible, compared to less than 20% of non-Hispanic whites. Crowding is worst for apartment dwellers, particularly in the Northeast.

Dr. Ashwini Sehgal, a Professor of Medicine at the Case Western Reserve University School of Medicine and lead author of the study commented, "To help contain family spread we should immediately offer free masks, gloves, and disinfection supplies to all families of potentially contagious persons. But we need to go further than that. To protect their loved ones, many doctors and nurses caring for COVID-19 patients have been put up in hotel rooms that lie vacant because of the pandemic. We need to offer that option to potentially infectious patients. Similar strategies have helped contain the pandemic in several Asian countries."

"Poverty and overt discrimination force many people of color into crowded and unsafe housing, fueling the spread of the pandemic," noted study co-author Dr. Steffie Woolhandler, a Distinguished Professor of Public Health at the City University of New York at Hunter College and Lecturer in Medicine at Harvard. "We need to implement emergency measures to minimize household spread. But we also need to assure that that all Americans can afford decent housing, and to finally begin enforcing the 1968 Fair Housing Act that too many landlords and realtors continue to flout."

FINDINGS

Researchers at the UCLA Jonsson Comprehensive Cancer Center and UCLA School of Dentistry have identified a potential new combination therapy to treat advanced head and neck squamous cell carcinoma, the most common type of head and neck cancer.

A study in mice found that using an anti-PD1 immunotherapy drug in combination with PTC209, an inhibitor that targets the protein BMI1, successfully stopped the growth and spread of the cancer, prevented reoccurrences and eliminated cancer stem cells. This is the first preclinical study to provide evidence that targeting BMI1 proteins enhances immunotherapy and eliminates cancer stem cells by activating antitumor immunity.

BACKGROUND

Immunotherapies using PD1 blockade have transformed the way people with difficult cancers are treated. Currently, PD1 blockade combined with chemotherapy is approved for recurrent or metastatic head and neck cancer, giving people whose disease would have otherwise been seen as a death sentence another option. However, response rates are not very high and response duration is relatively short, indicating that this type of cancer might be resistant to PD1 blockade.

To help overcome immunotherapy resistance, UCLA researchers have been studying the role of cancer stem cells and the protein BMI1. Growing evidence suggests cancer stem cells might be responsible for such resistance, as well as for relapse or reoccurrence, and BMI1, which functions in several cancers, including head and neck, has been found to control cancer stem cells' self-renewal. Targeting cancer stem cells may be critical for improving the efficacy of immunotherapy and preventing tumor relapse.

METHOD

The team used a mouse model of head and neck squamous cell carcinoma that fully mimicked human cancer development and metastasis, allowing them to perform lineage tracing of BMI1-positive cancer stem cells in an undisturbed tumor immune microenvironment. They then tested whether BMI1 cancer stem cells could be eradicated by PD1 blockade-based combination therapy using both pharmacological and genetic inhibition of BMI1. They found that inhibiting BMI1 not only helped eliminate the BMI1 cancer stem cells but also enhanced PD1 blockade by activating tumor cell-intrinsic immunity, which inhibited metastatic tumor growth and prevented tumor relapse.

IMPACT

Many people with advanced head and neck cancers who are treated with PD1 blockade and chemotherapy eventually see their cancer return and become resistant to the therapy. This preclinical study provides an important foundation for developing a new PD1 blockade-based combination therapy with BMI1 inhibitors that have the potential to help overcome resistance to the immunotherapy.

WASHINGTON, July 21, 2020 -- Twitter mentions show distinct community structure patterns resulting from communication preferences of individuals affected by physical distance between users and commonalities, such as shared language and history.

While previous investigations have identified patterns using other data, such as mobile phone usage and Facebook friend connections, research from the New England Complex Systems Institute looks at the collective effect of message transfer in the global community. The group's results are reported in an article in the journal Chaos, by AIP Publishing.

The scientists used the mentions mechanism in Twitter data to map the flow of information around the world. A mention in Twitter occurs when a user explicitly includes another @username in their tweet. This is a way to directly communicate with another user but is also a way to retransmit or retweet content.

VIDEO: https://www.youtube.com/watch?v=MUTFGt2tYbE

The investigators examined Twitter data from December 2013 and divided the world into 8,000 cells, each approximately 100 kilometers wide. A network was built on this lattice, where each node is a precise location and a link, or edge, is the number of Twitter users in one location who are mentioned in another location.

Twitter is banned in several countries and is known to be more prevalent in countries with higher gross domestic product, so this affects the data. Their results show large regions, such as the U.S. and Europe, are strongly connected inside each region, but they are also weakly connected to other areas.

"While strong ties keep groups cohesive, weak ties integrate groups at the large scale and are responsible for the spread of information systemwide," said co-author Leila Hedayatifar.

The researchers used a computational technique to determine modularity, a value that quantifies distance between communities on a network compared to a random arrangement. They also investigated a quantity known as betweenness centrality, which measures the number of shortest paths through each node. This measure highlights the locations that serve as connectors between many places.

By optimizing the modularity, the investigators found 16 significant global communities. Three large communities exist in the Americas: an English-speaking region, Central and South American countries, and Brazil in its own group. Multiple communities exist in Europe, Asia and Africa.

The data can also be analyzed on a finer scale, revealing subcommunities. Strong regional associations exist within countries or even cities. Istanbul, for example, has Twitter conversations that are largely restricted to certain zones within the city.

The investigators also looked at the effect of common languages, borders and shared history.

"We found, perhaps surprisingly, that countries who had a common colonizer have a decreased preference of interaction," Hedayatifar said.

She suggests hierarchical interactions with the colonizing country might inhibit interactions between former colonies.

In a new study, researchers have compared diseased colon with healthy tissue to better understand how inflammatory bowel disease (IBD) is linked to an increased risk of colorectal cancers, at a molecular level. Researchers from the Wellcome Sanger Institute and Cambridge University Hospitals found that the rate of DNA change within colon cells affected by IBD was more than double that in healthy colon, increasing the likelihood of these cells gaining DNA changes that could lead to cancer.

The study, published today (21 July) in Cell, also found that chronic inflammation associated with IBD disrupts the tissue structure of the colon, allowing cells to expand over an abnormally wide area. The results provide valuable insights into evolution within the body, and the development of IBD and colorectal cancers.

IBD primarily refers to ulcerative colitis and Crohn's disease, chronic illnesses characterised by inflammation of the digestive system that can be highly disruptive to a patient's quality of life. Between 1990 and 2017, the number of IBD cases worldwide rose from 3.7 million to 6.8 million*. The causes of the disease remain unknown, though it is thought that inflammation occurs as a result of an inappropriate immune response to gut microbes.

People suffering from IBD are at an increased risk of developing gastrointestinal cancers compared to the general population. Patients will undergo regular surveillance for this and may, in some cases, opt to undergo surgery to remove their entire colon in order to mitigate this risk.

In this new study, clinicians at Addenbrooke's Hospital, Cambridge provided colon tissue samples donated by 46 IBD patients, along with anonymised information about their medical history and treatment. Researchers at the Wellcome Sanger Institute then used laser-capture microdissection to cut out 446 individual crypts, the tiny cavities that make up colon tissue, so they could be whole-genome sequenced.

These sequences were analysed to discover the mutation rate in the tissue, the genetic relationship between crypts and any genes that were more mutated than normal. They were then compared to sequences from 412 crypts from 41 individuals without IBD, so that the effects of chronic inflammation on the DNA sequence could be observed.

The team found that there were more than twice as many DNA changes in the diseased tissue than in normal, and the longer the duration of the disease, the greater this excess.

The study also uncovered evidence of an evolutionary process whereby mutations in particular genes are under positive selection. Some of these positively-selected mutations were enriched in genes associated with colorectal cancers, shedding light on the link between IBD and certain cancers. The researchers also detected evidence of positive selection of mutations in genes associated with immune system regulation in the gut and the ability of the cells to fend off the bacteria resident in the colon.

Sigurgeir Olafsson, first author of the study from the Wellcome Sanger Institute, said: "How our bodies continue to evolve during our lifetime is a fundamental part of our biology. It has been fascinating to study the effect of a chronic disease on this process and uncover evidence that changes in the genetic sequence of gut cells could have a direct role in the onset of inflammatory bowel disease."

Dr Tim Raine, clinical lead for the inflammatory bowel disease (IBD) service at Addenbrooke's Hospital, Cambridge and Honorary Faculty member at the Wellcome Sanger Institute, said: "Colorectal cancer is one of the main clinical concerns when treating patients with IBD. In this study, we found that normal mutational processes that are operative in us all are accelerated in the IBD affected gut, leading to a more than two-fold increase in the rate at which some gut cells acquire mutations, and this underpins the increased cancer risk in IBD."

Dr Peter Campbell, an author on the study from the Wellcome Sanger Institute, said: "The role of somatic mutations in cancer susceptibility has long been appreciated. It is exciting to see the methods that we and others have used to understand cancers now being applied to other common diseases. These approaches have given us unique insights into the effects of inflammatory bowel disease on the DNA sequence of the inflamed tissue."

A previously unexplained observation in IBD is that repeated flares of inflammation tend to affect the same patch of tissue, suggesting some permanent alterations to the colon. These findings highlight genetic mutations as a possible explanation, with some positively-selected mutations in immune regulation genes occurring in the same regions of the bowel affected by chronic inflammation.

Dr Carl Anderson, lead author of the study from the Wellcome Sanger Institute, said: "We know that DNA changes contribute to the development of cancer, but their role in common non-cancerous diseases like inflammatory bowel disease (IBD) has not been extensively studied. Our study revealed that somatic changes in the DNA sequence of the cells that line our gut may contribute to the development of IBD. I strongly believe that studying somatic mutations in all common diseases, not just IBD and cancers, has the potential to provide novel insights into disease biology and highlight potential drug targets."

WASHINGTON, July 21, 2020 -- Episodes of social unrest rippled throughout Chile in 2019 and disrupted the daily routines of many citizens. Researchers specializing in economics, mathematics and physics in Chile and the U.K. banded together to explore the surprising social dynamics people were experiencing.

To do this, they combined well-known epidemic models with tools from the physics of chaos and interpreted their findings through the lens of social science as economics.

In the journal Chaos, from AIP Publishing, the team reports that social media is changing the rules of the game, and previously applied epidemic-like models, on their own, may no longer be enough to explain current rioting dynamics. Using epidemiological mathematical models to understand the spread of infectious diseases dates back more than 100 years.

"In the 1970s, this type of methodology was used to understand the dynamics of riots that occurred in U.S. cities in the 1960s," said Jocelyn Olivari Narea, co-author and an assistant professor at Adolfo Ibáñez University in Chile. "More recently, it was used to model French rioting events in 2005."

From a mathematical point of view, the team's work is based on the SIR epidemiological model, known for modeling infectious disease spread. This technique separates the population into susceptible, infectious and recovered individuals.

"Within a rioting context, someone 'susceptible' is a potential rioter, an 'infected individual' is an active rioter, and a 'recovered person' is one that stopped rioting," explained co-author Katia Vogt-Geisse. "Rioting spreads when effective contact between an active rioter and a potential rioter occurs."

They discovered that the SIR model uses Hamiltonian mechanics for mathematics, just like Newton's laws for physics.

"This allowed us to apply well-known tools of the physics of chaos to show that within the presence of an external force, the dynamics become very rich," said co-author Sergio Rica Mery. "The external force that we included in the model represents the occasional trigger that increases rioting activity."

When including such triggers, the team found the way a sequence of events occurs varies greatly based on the initial number of potential rioters and active rioters.

"Even the sequence of rioting events can be chaotic," Rica Mery said. "Rich dynamics reveal the complexity involved in making predictions of rioting activity."

The team's work comes at a timely moment as social unrest is becoming more common --even within the context of the current pandemic.

"We just saw episodes of rioting in Minnesota due to racial unrest and how it ended up spreading to various locations within the U.S. and even abroad," Olivari Narea said.

The team pointed out it was surprising that the idea of disease spread can be well applied to rioting activity spread to obtain a good fit of rioting activity data.

"While you might think that the study of disease transmission and problems of a social nature vary greatly, our work shows epidemiological models of the most simple SIR type, enriched by triggers and tools of the physics of chaos, can describe rioting activities well," Vogt-Geisse said.