Bed bugs modify microbiome of homes they infest

NORTH CAROLINA STATE UNIVERSITY

IMAGE: BED BUGS CAN MODIFY MICROBIAL COMMUNITIES IN HOME THEY INFEST. view more 

CREDIT: BENOIT GUENARD

Homes infested by bed bugs appear to have different bacterial communities - often referred to as microbiomes - than homes without bed bugs, according to a first-of-its-kind study from North Carolina State University. In addition, once bed bug infestations were eradicated, home microbiomes became more similar to those in homes that never had bed bugs. The findings could be an important step in lifting the veil on the factors involved in indoor environmental quality and how to improve it.

Microbes can affect indoor air quality. So NC State entomologists Coby Schal and Madhavi Kakumanu wanted to learn more about the microbiomes of bed bugs, whether bed bugs can shape the microbial community in homes they infest, and whether eliminating bed bugs changes the microbiome of homes that were once infested.

The study, held in an apartment complex in Raleigh, compared the microbiomes of bed bugs with the microbiomes in the household dust of infested homes as well as the microbiomes in apartments that had no bed bugs. Nineteen infested homes were studied over the course of four months; seven were treated with heat to eliminate bed bugs after the initial sample was taken, while 12 infested homes were treated after one month. These homes were compared with 11 homes that had no bed bugs.

The results showed similarities between the microbiomes of bed bugs and the dust-associated microbiomes of infested homes, mostly through the presence of Wolbachia, a symbiotic bacterium that comprises the majority of the bacterial abundance in bed bugs. Bed bug and infested home microbiomes differed significantly from the microbial communities of uninfested homes.

"There is a link between the microbiome of bed bugs and the microbiome of household dust in bed bug infested homes," said Schal, the Blanton J. Whitmire Distinguished Professor of Entomology at NC State and co-corresponding author of the paper. "No previous study has reported the impact of chronic pest infestations on indoor microbial diversity."

The study also showed that, after bed bugs were eliminated, infested home microbiomes gradually became more like those in homes without bed bugs.

"The elimination of the bed bugs resulted in gradual shifts in the home microbial communities toward those of uninfested homes," Kakumanu, an NC State research scholar in Schal's lab and co-corresponding author of the study, said. "This paper is the first experimental demonstration that eliminating an indoor pest alters the indoor microbiome toward that of uninfested homes."

"Bed bug infestations are problematic in many homes in both developed and developing countries," Schal said. "There is a critical need to investigate infestations from the perspective of indoor environmental quality, and this paper represents a first step toward this end." 

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The study appears in Science of the Total Environment. Funding for the work came from NC State's Blanton J. Whitmire endowment, as well as the U.S. Department of Housing and Urban Development Healthy Homes program (NCHHU0017-13, NCHHU0053-19), the Alfred P. Sloan Foundation (2013-5-35 MBE) and the National Science Foundation (DEB-1754190). Seed funds came from NC State's Center for Human Health and the Environment (CHHE, P30ES025128), funded by the National Institute of Environmental Health Sciences.

Note to editors: An abstract of the paper follows.

"Bed bugs shape the indoor microbial community composition of infested homes"

Authors: Madhavi L. Kakumanu, Alexis M. Barbarin, Richard G. Santangelo and Coby Schal, North Carolina State University: Zachary C. DeVries, University of Kentucky

Published: July 7, 2020 in Science of the Total Environment

DOI: 10.1016/j.scitotenv.2020.140704

Abstract: Indoor pests, and the allergens they produce, adversely affect human health. Surprisingly, however, their effects on indoor microbial communities have not been assessed. Bed bug (Cimex lectularius) infestations pose severe challenges in elderly and low-income housing. They void large amounts of liquid feces into the home environment, which might alter the indoor microbial community composition. In this study, using bed bug-infested and uninfested homes, we showed a strong impact of bed bug infestations on the indoor microbial diversity. Floor dust samples were collected from uninfested and bed bug-infested homes and their microbiomes were analyzed before and after heat interventions that eliminated bed bugs. The microbial communities of bed bug-infested homes were radically different from those of uninfested homes, and the bed bug endosymbiont Wolbachia was the major driver of this difference. After bed bugs were eliminated, the microbial community gradually shifted toward the community composition of uninfested homes, strongly implicating bed bugs in shaping the dust-associated environmental microbiome. Further studies are needed to understand the viability of these microbial communities and the potential risks that bed bug-associated microbes and their metabolites pose to human health.

States slow to implement stay-at-home orders saw higher rates of COVID-19 deaths 

Researchers from Children's Hospital of Philadelphia and University of Pennsylvania estimate the efficacy of social distancing

CHILDREN'S HOSPITAL OF PHILADELPHIA

 

Philadelphia, July 15, 2020 - As the COVID-19 pandemic spread across the United States, governments at the state and local levels issued emergency declarations and shut down schools. With no treatment and no vaccine, this was seen as the best way to stop the spread of the SARS-CoV-2 virus. Researchers from Children's Hospital of Philadelphia (CHOP) and the University of Pennsylvania's Perelman School of Medicine have conducted one of the first studies to measure the efficacy of social distancing in the early days of the COVID-19 pandemic. They found that states that were slow to implement such orders saw higher COVID-19 death rates.

The findings were published this month in Clinical Infectious Diseases.

Researchers analyzed more than 55,000 COVID-19 deaths across 37 states between January 21, 2020 and April 29, 2020. They tested the association between the timing of emergency declarations and school closings with 28-day mortality. The findings showed that each day of delayed intervention lead to a 5 to 6% increase in mortality risk. Even when excluding New York and New Jersey to account for the impact of excess deaths from the New York City area, the models still showed similar results.

"Before this study, we assumed social distancing worked based on modeling and studies of prior pandemics, but we didn't have substantial quantitative data to show its effectiveness for COVID-19," said Nadir Yehya, MD, lead author and Assistant Professor in the Division of Critical Care Medicine at CHOP and the Hospital of the University of Pennsylvania. "Our analyses demonstrate that states that issued emergency declarations earlier helped curb the spread of the disease. These results confirm how important it is to implement social distancing measures early to reduce Covid-19 deaths."

The researchers were able to adjust for multiple confounders, including population density, age, and demographics, but were unable to adjust for potentially important confounders, such as outbreaks in long-term care facilities. Nor did their data explore individual behavior or the association between the duration of social distancing orders and outcomes.

"The implementation of social distancing measures is fundamentally political, as the process is decided upon by elected officials," Dr. Yehya said. "Real-time, scientific evidence of the efficacy of these measures will be helpful for informing future policy decisions."

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The study was done in collaboration with Atheendar Venkataramani, MD, PhD, Assistant Professor in the Department of Medical Ethics and Health Policy at the Perelman School of Medicine, and Miacheal Harhay, PhD, MPH, Assistant Professor of Epidemiology at the Perelman School of Medicine.

About Children's Hospital of Philadelphia: Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals, and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country. In addition, its unique family-centered care and public service programs have brought the 546-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit http://www.chop.edu

Identifying sources of deadly air pollution in the United States 

UNIVERSITY OF MINNESOTA

MINNEAPOLIS/SAINT PAUL (07/15/20) -- A new study from University of Minnesota researchers provides an unprecedented look at the causes of poor air quality in the United States and its effects on human health.

The research, to be published Wednesday in the journal Environmental Science and Technology Letters, finds that air pollution from sources in the United States leads to 100,000 deaths in the U.S. each year. About half of these deaths are from burning fossil fuels, but researchers also identified less obvious sources of lethal pollution.

"People usually think of power plants and cars, but nowadays, livestock and wood stoves are as big of a problem. It's also our farms and our homes." said Sumil Thakrar, postdoctoral research associate in the Departments of Bioproducts and Biosystems Engineering and Applied Economics.

The researchers found that while some sectors of the economy, such as electricity production and transportation, have reduced pollution amid government regulations, others have received less attention, including agriculture and residential buildings.

Researchers examined U.S. Environmental Protection Agency data on all pollution sources in the United States, including their location and how much pollution they emit. They then used newly-developed computer models to determine where pollution travels and how it affects human health.

Researchers focused on one particularly harmful pollutant: fine particulate matter, also known as PM2.5, which is associated with heart attacks, strokes, lung cancer and other diseases. In examining the data, they discovered that about half of all PM2.5 air pollution-related deaths are from burning fossil fuels, with the remaining largely from animal agriculture, dust from construction and roads, and burning wood for heating and cooking.

"Essentially we're asking, 'what's killing people and how do we stop it?'" Thakrar said. "The first step in reducing deaths is learning the impact of each and every emission source."

In the U.S., air quality is largely regulated by the federal government, which sets maximum allowable levels of pollution in different areas. States and local governments are then charged with enforcing those limits. The authors suggest regulators can improve this broad-brush approach by focusing instead on reducing emissions from specific sources.

"Targeting particularly damaging pollution sources is a more efficient, and likely more effective, way of regulating air quality," said Jason Hill, professor in the Department of Bioproducts and Biosystems Engineering within the University's College of Food, Agricultural and Natural Resource Sciences and College of Science and Engineering. "Think of springing a leak in your boat while out fishing. Why fret too much about how much water is coming in when what you really should be doing is plugging the hole?"

The researchers also report a surprising finding about the sources of PM2.5 responsible for harming human health. Most people are familiar with PM2.5 as soot -- such as the exhaust from a dirty bus -- or road dust. But PM2.5 also forms from other pollutants like ammonia.

Ammonia is released from animal manure and the fertilization of crops. However, unlike many other sources of PM2.5, ammonia is not regulated to any large extent, despite being responsible for about 20,000 deaths, or one-fifth of all deaths caused by PM2.5 pollution from human activity.

To improve air quality in the future, the authors suggest more drastic reductions of emissions from sources that are already regulated, such as electricity generation and passenger vehicles. They also suggest novel ways to target pollutant sources that have not been as extensively regulated, such as manure management, changing personal diets and improving formulations of cleaning supplies, paints and inks.

This research -- the underlying data and results of which are available to the public -- can complement current efforts to mitigate climate change and other environmental problems.

"Our work provides key insights into the sources of damage caused by air pollution and suggests ways to reduce impacts," said Thakrar. "We hope policymakers and the public will use this to improve the lives of Americans."

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BU researcher outlines coronavirus media failures, harms, and recommendations

COVID-19 is an urgent crisis that makes careful communication about it even more important

BOSTON UNIVERSITY SCHOOL OF MEDICINE

 

In a new JAMA editorial, a Boston University School of Public Health (BUSPH) researcher and a health research journalist outline common ways that media, governments, and industry and academic public relations press releases have incompletely and misleadingly reported coronavirus research, and how they can do better. "The COVID-19 pandemic has created perhaps the most challenging time for science communication in decades. Races are underway in parallel: to find answers to perplexing coronavirus questions, to announce research findings to clinical and scientific colleagues, and to report those findings to a confused and concerned global audience," write Dr. Richard Saitz, professor and chair of community health sciences at BUSPH, and Gary Schwitzer, founder and publisher of HealthNewsReview.org. "There are no winners in these races if harm--even though unintentional--is wrought by the dissemination of hurried, incomplete, biased misinformation," they write. "Trust in science, medicine, public relations and journalism may be in jeopardy in the intersection where these professions meet." By way of example, Saitz and Schwitzer describe how three drugs--remdesivir, dexamethasone, and hydroxychloroquine--have been touted as COVID cures, without explanations of the limits of the evidence. These rushed and incomplete announcements have led, among other consequences, to shortages, government stockpiling, and a baffled public: In the case of hydroxychloroquine, they write, "News stories and social media reports took readers on a roller coaster ride, alternately reporting efficacy, lack of efficacy, and harm, reporting dutifully on the results of each latest study." Instead, Saitz and Schwitzer recommend greater caution and more detail, including highlighting limitations, specifying patient populations, and describing new findings in the larger context of previous research. It may be a hard pill to swallow, but, they write, "It is important that complexity be mentioned and considered even if it is not popular among layperson readers."

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Read the full editorial here: https://jamanetwork.com/journals/jama/fullarticle/2768397

About the Boston University School of Public Health

Founded in 1976, the Boston University School of Public Health is one of the top five ranked private schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations--especially the disadvantaged, underserved, and vulnerable--locally and globally.

Plant-based diets promote healthful aging, according to new editorial 

PHYSICIANS COMMITTEE FOR RESPONSIBLE MEDICINE

WASHINGTON--Adopting a plant-based diet can help promote healthful aging and mitigate the global burden of disease, according to an editorial published in the Journal of the American College of Nutrition.

Researchers with the Physicians Committee for Responsible Medicine reviewed clinical trials and epidemiological studies related to aging and found that while aging increases the risk for noncommunicable chronic diseases, healthful diets can help. The editorial shows that plant-based diets can reduce the risk of diseases such as type 2 diabetes, cancer, and heart disease by almost 50% and could cut cardiometabolic-related deaths in the United States by half.

"Modulating lifestyle risk factors and adopting a healthful diet are powerful tools that may delay the aging process, decrease age-associated co-morbidities and mortality, and increase life expectancy," write the authors. The authors cite studies showing that plant-based diets rich in fruits, vegetables, grains, and legumes:

• Reduce the risk of developing metabolic syndrome and type 2 diabetes by about 50%.
• Reduce the risk of coronary heart disease events by an estimated 40%.
• Reduce the risk of cerebral vascular disease events by 29%.
• Reduce the risk of developing Alzheimer's disease by more than 50%.
• May reduce the risk for cognitive diseases such as Alzheimer's disease by almost 50%.

The researchers also note that plant-based diets have been tied to increased life expectancy, as evidenced by the world's "Blue Zones," where populations subsist mostly on plant-based foods rich in phytochemicals and antioxidants that have been associated with longer life expectancy.

"The global population of adults 60 years old or older is expected to double from 841 million to 2 billion by 2050, presenting clear challenges for our health care system," says study author Hana Kahleova, MD, PhD, director of clinical research for the Physicians Committee. "Fortunately, simple diet changes can go a long way in helping populations lead longer, healthier lives."

The authors also note that these improvements in health will reduce health care costs caused by chronic diseases. According to the Centers for Disease Control and Prevention, lifestyle-related chronic diseases are the leading cause of death and disability in the United States, accounting for the majority of the nation's annual $3.5 trillion in health care spending.

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Simultaneous, reinforcing policy failures led to Flint water crisis, providing lessons during pandemic

UNIVERSITY OF MICHIGAN

Concurrent failures of federal drinking water standards and Michigan's emergency manager law reinforced and magnified each other, leading to the Flint water crisis, according to a University of Michigan environmental policy expert.

Flint's experience offers lessons during the COVID-19 pandemic, which has exacerbated local financial challenges while highlighting the importance of access to clean, safe drinking water, said U-M's Sara Hughes, an assistant professor at the School for Environment and Sustainability.

"As we wrestle to combat the coronavirus, we should keep in mind that building healthy communities starts with a renewed commitment to investing in 21st-century drinking water systems and supporting cities as they navigate systemic financial challenges," Hughes said. "Learning from the Flint water crisis requires counteracting and confronting the marginalizing effects of infrastructure underinvestment and urban austerity measures."

The Flint water crisis resulted from simultaneous failures of the federal Safe Drinking Water Act and Michigan's Local Financial Stability and Choice Act, Hughes writes in an article published July 13 in the journal Perspectives on Politics. Also known as Public Act 436, the Michigan law places cities deemed by the state to be experiencing fiscal distress under the control of a state-appointed emergency manager.

Both policies rationalize complex problems--safe drinking water and municipal financial distress--by providing purely technical solutions, and the weaknesses of each reinforced and magnified the harmful consequences of the other for the residents of Flint, according to Hughes.

For nearly 18 months, from April 2014 to October 2015, the city of Flint delivered inadequately treated Flint River water to residents, exposing thousands to elevated lead levels and other contaminants. Poor children and families were particularly affected.

At both the state and federal levels, the primary response to the Flint water crisis has been to strengthen drinking water safety standards and monitoring practices, Hughes said. But providing safe drinking water to city residents is only partly a technical problem.

Much less attention has been paid to funding and supporting local governments in ways that ensure their capacity to build and maintain infrastructure, provide reliable services, and sustain meaningful dialogue and engagement with their residents, according to Hughes.

Failure to address these longstanding problems will complicate efforts to recover from the coronavirus pandemic, especially in hard-hit places like Southeast Michigan, which has the state's highest concentration of COVID-19 cases.

"If addressed, these policy failures would mitigate against the disproportionate and unequal patterns emerging in the coronavirus outbreak," Hughes said. "But absent change, poor and minority cities remain vulnerable to the marginalizing effects of these multiple and reinforcing rationalized policy domains."

By a rationalized policy Hughes means one that is presented as purely technical in nature and politically neutral. Techno-rational approaches to policy hold out the promise of more effective, unbiased decision-making, but they often cloak decisions and priorities in the language of rationality and science while failing to consider the public's preferences, according to Hughes.

Rationalized policy approaches were at the heart of the Flint water crisis, involving both the federal drinking water act and the state emergency manager law.

Flint first came under emergency management in 2011 through the law that preceded Public Act 436, then in 2012 through the provisions of PA 436, which was developed and championed by former Michigan Gov. Rick Snyder. Flint's state-appointed emergency managers made or forced decisions about the city's water supplies and treatment protocols that were ostensibly made with the goal of cutting costs.

The second policy failure implicated in the Flint water crisis involves the federal Safe Drinking Water Act's Lead and Copper Rule. The LCR provides two important sets of criteria: water quality standards and treatment/testing protocols for lead and copper in drinking water systems.

The law requires that local water utilities monitor and test their water supplies and report their results to the state government, which in turn reports all data to the U.S. Environmental Protection Agency. The EPA is ultimately responsible for ensuring compliance.

When Flint switched its drinking water source to the Flint River in April 2014, the state environmental quality department failed to require the city to treat the water for corrosion, as would be necessary to meet federal Safe Drinking Water Act (SDWA) standards.

Federal standards for lead in drinking water are 15 parts per billion. Lead levels of up to 1,000 ppb were detected in Flint homes during the water crisis, yet enforcement actions were not triggered.

"The fact that such systemic and prolonged noncompliance, and clear evidence of a threat to public health, failed to trigger regulatory action by EPA calls into question the adequacy of public protections embedded in the SDWA and LCR," Hughes said.

In much the same way that Michigan's emergency manager law represents a rationalized approach to municipal financial distress, the federal Lead and Copper Rule is a rationalized approach to protecting human health, according to Hughes.

"The provisions and standards in the LCR create a policy environment that facilitates decision-making that is reactionary, prioritizes cost-effectiveness, excludes the public and tolerates risk," she said. The LCR has no enforceable health-based standard "and does not protect any individual or household from exposure to elevated lead levels."

In 2018, the state of Michigan passed its own set of stricter standards for lead, shifting to a lower 12 ppb standard and requiring that communities replace 5% of lead service lines annually. At the national level, the EPA has submitted proposed revisions to the LCR to the Office of Management and Budget, but they have yet to take effect.

Critically, the policy changes resulting from the Flint water crisis have not extended to a reevaluation of how municipal financial distress is addressed and prevented, according to Hughes. Michigan's emergency manager law remains unchanged. Poor, minority U.S. communities consistently receive lower-quality drinking water, and lead contamination cases fit a pattern of low-income, unequal and largely black cities, according to Hughes.

The study is based on interviews with local activists, decision-makers, scientists, journalists and scholars working in or with the city of Flint, as well as a review of reports, testimony, newspaper articles and secondary demographic and financial data.

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Study abstract: Flint, Michigan, and the Politics of Safe Drinking Water in the United States

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases

'Lab in a suitcase' could hold the key to safer water and sanitation for millions

A portable testing lab that fits into a suitcase is being hailed as the key to tackling one of the world's biggest dangers to health.

NEWCASTLE UNIVERSITY

IMAGE: USING SMALLER VERSIONS OF SPECIALIST EQUIPMENT FOUND IN MICROBIOLOGY LABS, THE NEW 'LAB IN A SUITCASE' -- DEVELOPED BY NEWCASTLE UNIVERSITY, UK WITH PARTNERS IN ETHIOPIA, AND BELIEVED TO BE... view more 

CREDIT: NEWCASTLE UNIVERSITY, UK

A portable testing lab that fits into a suitcase is being hailed as the key to tackling one of the world's biggest dangers to health.

Experts from Newcastle University UK, have been working with the Addis Ababa Water and Sewerage Authority (AAWSA), Addis Ababa University (AAU) and the International Water Management Institute (IWMI) to ensure waterborne hazards can be identified in a quicker, easier and ultimately cheaper way, anywhere in the world.

Using smaller and less expensive versions of the same type of specialist equipment found in state-of-the-art microbiology laboratories in the UK, the new suitcase lab - believed to be a world first - enables screening of millions of bacteria in a single water sample, instead of running many tests in parallel to look for different pathogens.

Genetic analysis can bring to light numerous hazards potentially present in water, but such analysis is currently carried out in a laboratory, using large and expensive machines. These facilities are often not available in developing countries, and the process of sending samples from the affected country to the UK for detailed analysis can take more than a month.

The portable lab means scientists can go direct to the location where a waterborne disease is thought to be present and screen a water sample for genetic material - with results available within a day or two.

The data can be used for measuring the effectiveness of wastewater treatment, faecal pollution source tracking and the identification of waterborne hazards in surface and groundwater. The rapid data generation gives public health officials more opportunity to quickly identify and deal with local hazards, potentially saving countless lives.

After initial on-site testing on samples collected at Birtley sewage treatment plant in North East England, the suitcase lab was used to carry out water quality screening in the Akaki River catchment near Addis Ababa, Ethiopia. These achievements have just been published in the journal Water Research.

Dr David Werner, Professor in Environmental Systems Modelling, Newcastle University, explains: "By taking advantage of innovative technologies to make it easier and faster to carry out on-site water quality assessments, and with our Ethiopian colleagues, we have demonstrated a way to study genetic material with affordable resources almost anywhere in the world.

"With our portable laboratory we successfully screened millions of bacteria in Akaki River water samples and discovered a high prevalence of Arcobacter butzleri, a still poorly understood waterborne hazard that can cause watery diarrhoea. Unfortunately, diarrhoea is still a leading cause of death among children under the age of five."

Government advice to "wash your hands frequently" exemplifies the importance of safe water and sanitation for hygiene and public health. But according to the United Nations, six in 10 people lack access to safely managed sanitation facilities and three in 10 people in the world lack access to safely managed drinking water services.

As well as reducing the time required to measure water quality, the project aims to enable the independent use of the tools by researchers and water systems engineers in Ethiopia. Dr Alemseged Tamiru Haile from the IWMI is confident that the scientific break-through will make a difference in Ethiopia.

"Our collaboration with Newcastle University in terms of carrying out the field work and analysis provided an opportunity for the hands-on training of 13 junior experts in Ethiopia at AAWSA facilities," he says. "One AAWSA staff member then visited Newcastle to receive intensive training in water quality monitoring with the portable laboratory. Academics from AAU can now integrate the novel approach into their curriculum. The equipment items we have assembled in the portable laboratory are affordable for AAU and AAWSA."

AAWSA is constructing more sewage treatment plants in Addis Ababa, and the team will continue their monitoring in the Akaki catchment to provide evidence for the benefits of these investments in public health.

Dr Kishor Acharya is the early career scientist at Newcastle University who has led the development of the portable molecular toolbox. He has delivered training workshops in portable metagenomics to junior academics and laboratory technicians from research institutions, NGOs, and government agencies in Tanzania, Thailand, Malaysia, Nepal, India and Ethiopia.

Dr Acharya, who is originally from Nepal, says that the portable lab kit could easily be used in many different contexts to screen for dangerous pathogens. "I want to demonstrate the applicability of the mobile toolkit and the protocols we've developed for microbial hazard surveying to other disciplines," he explains. "In the future, this kit could potentially be used as a way to assure food and drink safety, efficient health services, productive agriculture and beyond."

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The project has been delivered through the £17 million Global Challenges Research Fund Water Security and Sustainable Development Hub.

New solar material could clean drinking water 

U.S. ARMY RESEARCH LABORATORY

IMAGE: WITH ARMY FUNDING RESEARCHERS AT THE UNIVERSITY OF ROCHESTER HAVE DEVELOPED AN ALUMINUM PANEL THAT ANGLED AT THE SUN PURIFIES WATER. view more 

CREDIT: COURTESY UNIVERSITY OF ROCHESTER

RESEARCH TRIANGLE PARK, N.C. (July 13, 2020) - Providing clean water to Soldiers in the field and citizens around the world is essential, and yet one of the world's greatest challenges. Now a new super-wicking and super-light-absorbing aluminum material developed with Army funding could change that.

With funding from the Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory, researchers at the University of Rochester have developed a new aluminum panel that more efficiently concentrates solar energy to evaporate and purify contaminated water.

"The Army and its warfighters run on water, so there is particular interest in basic materials research that could lead to advanced technologies for generating drinking water," said Dr. Evan Runnerstrom, program manager at ARO. "The combined super-wicking and light-absorbing properties of these aluminum surfaces may enable passive or low-power water purification to better sustain the warfighter in the field."

The researchers developed a laser processing technology that turns regular aluminum pitch black, making it highly absorptive, as well as super-wicking (it wicks water uphill against gravity). They then applied this super absorptive and super-wicking aluminum for this solar water purification.

The technology featured in Nature Sustainability, uses a burst of femtosecond (ultrashort) laser pulses to etch the surface of a normal sheet of aluminum. When the aluminum panel is dipped in water at an angle facing the sun, it draws a thin film of water upwards over the metal's surface. At the same time, the blackened surface retains nearly 100-percent of the energy it absorbs from the sun to quickly heat the water. Finally, the wicking surface structures change the inter-molecular bonds of the water, increasing the efficiency of the evaporation process even further.

"These three things together enable the technology to operate better than an ideal device at 100 percent efficiency," said Professor Chunlei Guo, professor of optics at University of Rochester. "This is a simple, durable, inexpensive way to address the global water crisis, especially in developing nations."

Experiments by the lab show that the method reduces the presence of all common contaminants, such as detergent, dyes, urine, heavy metals and glycerin, to safe levels for drinking.

The technology could also be useful in developed countries for relieving water shortages in drought-stricken areas, and for water desalinization projects, Guo said.

Using sunlight to boil has long been recognized as a way to eliminate microbial pathogens and reduce deaths from diarrheal infections, but boiling water does not eliminate heavy metals and other contaminants.

Solar-based water purification; however, can greatly reduce these contaminants because nearly all the impurities are left behind when the evaporating water becomes gaseous and then condenses and gets collected.

The most common method of solar-based water evaporation is volume heating, in which a large volume of water is heated but only the top layer can evaporate. This is obviously inefficient, Guo said, because only a small fraction of the heating energy gets used.

A more efficient approach, called interfacial heating, places floating, multi-layered absorbing and wicking materials on top of the water, so that only water near the surface needs to be heated. But the available materials all have to float horizontally on top of the water and cannot face the sun directly. Furthermore, the available wicking materials become quickly clogged with contaminants left behind after evaporation, requiring frequent replacement of the materials.

The aluminum panel the researchers developed avoids these difficulties by pulling a thin layer of water out of the reservoir and directly onto the solar absorber surface for heating and evaporation.

"Moreover, because we use an open-grooved surface, it is very easy to clean by simply spraying it," Guo said. "The biggest advantage is that the angle of the panels can be continuously adjusted to directly face the sun as it rises and then moves across the sky before setting - maximizing energy absorption."

The Army and Guo are exploring transition opportunities to further develop this technology within DOD laboratories and private industry.

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In addition to the Army, this research received funding from the Bill and Melinda Gates Foundation and the National Science Foundation.

CCDC Army Research Laboratory is an element of the U.S. Army Combat Capabilities Development Command. As the Army's corporate research laboratory, ARL discovers, innovates and transitions science and technology to ensure dominant strategic land power. Through collaboration across the command's core technical competencies, CCDC leads in the discovery, development and delivery of the technology-based capabilities required to make Soldiers more lethal to win the nation's wars and come home safely. CCDC is a major subordinate command of the U.S. Army Futures Command.

Lasers etch an efficient way to address global water crisis

UNIVERSITY OF ROCHESTER

 

IMAGE: A LASER-ETCHED, ENERGY ABSORBING, WATER WICKING METAL SURFACE, CONTINUALLY ANGLED DIRECTLY AT THE SUN, PROVIDES A CHEAP, EFFICIENT WAY TO PURIFY WATER FROM SUNLIGHT. THE TECHNOLOGY WAS DEVELOPED BY THE... view more 

CREDIT: H.M. CAO/UNIVERSITY OF ROCHESTER

Lasers etch a simple way to address global water crisis

Amid the coronavirus pandemic, people in developed countries are assured of ample supplies of clean water to wash their hands as often as needed to protect themselves from the disease. And yet, nearly a third of the world's population is not even assured of clean water for drinking.

University of Rochester researchers have now found a way to address this problem by using sunlight - a resource that everyone can access - to evaporate and purify contaminated water with greater than 100 percent efficiency.

How is this possible?

In a paper in Nature Sustainability, researchers in the laboratory of Chunlei Guo, professor of optics, demonstrate how a burst of femtosecond laser pulses etch the surface of a normal sheet of aluminum into a super wicking (water attracting), super energy absorbing material.

When placed in water at an angle facing the sun, the surface:

• Draws a thin film of water upwards over the metal's surface
• Retains nearly 100 percent of the energy it absorbs from the sun to quickly heat the water
• Simultaneously, changes the inter-molecular bonds of the water, significantly increasing the efficiency of the evaporation process even further.

"These three things together enable the technology to operate better than an ideal device at 100 percent efficiency," says Guo, who is also affiliated with the University's Physics and Materials Science programs. "This is a simple, durable, inexpensive way to address the global water crisis, especially in developing nations."

Experiments by the lab show that the method reduces the presence of all common contaminants, such as detergent, dyes, urine, heavy metals, and glycerin, to safe levels for drinking.

The technology could also be useful in developed countries for relieving water shortages in drought-stricken areas, and for water desalinization projects, Guo says.

Easy to clean, easy to aim

Using sunlight to boil has long been recognized as a way to eliminate microbial pathogens and reduce deaths from diarrheal infections. But boiling water does not eliminate heavy metals and other contaminants.

Solar-based water purification, however, can greatly reduce these contaminants because nearly all the impurities are left behind when the evaporating water becomes gaseous and then condenses and gets collected.

The most common method of solar-based water evaporation is volume heating, in which a large volume of water is heated but only the top layer can evaporate. This is obviously inefficient, Guo says, because only a small fraction of the heating energy gets used.

A more efficient approach, called interfacial heating, places floating, multi-layered absorbing and wicking materials on top of the water, so that only water near the surface needs to be heated. But the available materials all have to float horizontally on top of the water and cannot face the sun directly, Guo says. Thus, the approach is less energy efficient. Furthermore, the available wicking materials become quickly clogged with contaminants left behind after evaporation, requiring frequent replacement of the materials.

The panel developed by the Guo lab avoids these inefficiencies by pulling a thin layer of water out of the reservoir and directly onto the solar absorber surface for heating and evaporation. "Moreover, because we use an open-grooved surface, it is very easy to clean by simply spraying it," Guo says.

"The biggest advantage," he adds, "is that the angle of the panels can be continuously adjusted to directly face the sun as it rises, and then moves across the sky before setting" - maximizing energy absorption. "There was simply nothing else resembling what we can do here," Guo says.

Latest in series of applications

The project was supported by funding from the Bill and Melinda Gates Foundation, the National Science Foundation, and the US Army Research Office.

"The Army and its warfighters run on water, so there is particular interest in basic materials research that could lead to advanced technologies for generating drinking water," said Evan Runnerstrom, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "The superwicking and light-absorbing properties of these aluminum surfaces may enable passive or low-power water purification to better sustain the warfighter in the field."

In addition to using femto-second laser etching technology to create superhydrophobic (water repellent), superhydrophilic (water-attracting), and super energy absorbing metals, the Guo lab has created metallic structures that do not sink no matter how often they are forced into water or how much it is damaged or punctured.

Prior to creating the water attracting and repellent metals, Guo and his assistant, Anatoliy Vorobyev, demonstrated the use of femto-second laser pulses to turn almost any metal pitch black. The surface structures created on the metal were incredibly effective at capturing incoming radiation, such as light. But they also captured light over a broad range of wavelengths.

Subsequently, his team used a similar process to change the color of a range of metals to various colors, such as blue, gold, and gray. The applications could include making color filters and optical spectral devices, using a single laser in a car factory to produce cars of different colors; or proposing with a gold engagement ring that matches the color of your fiancee's blue eyes.

The lab also used the initial black and colored metal technique to create a unique array of nano- and micro-scale structures on the surface of a regular tungsten filament, enabling a light bulb to glow more brightly at the same energy usage.

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In addition to Guo, coauthors include lead author Subhash Singh, Mohamed ElKabbash, Zilong Li, Xiaohan Li, Bhabesh Regmi, Matthew Madsen, Sohail Jalil, Zhibing Zhan, and Jihua Zhang, all of the Guo Lab. Among them, four are undergraduate students.

McLean hospital study examines the cost-effectiveness of esketamine

Researchers find this nasal spray for treatment-resistant depression is currently too expensive for widespread use

MCLEAN HOSPITAL

 

IMAGE: STUDY DETERMINED THAT ESKETAMINE COST MUST REDUCE IN ORDER TO BE BENEFICIAL TO PATIENTS WITH DEPRESSION view more 

CREDIT: MCLEAN HOSPITAL

Highlights: * Study estimated the cost-effectiveness of esketamine, a novel intranasally dosed antidepressant for patients with treatment-resistant depression * Researchers employed a decision-analytic model to simulate the effects of treatment with esketamine versus oral antidepressants from both societal and health care sector perspectives * Study concluded that the price of esketamine must fall by more than 40% to be cost-effective for management of treatment-resistant depression in the United States

A paper authored by researchers from McLean Hospital has determined that esketamine, a nasal spray to treat severe depression, is currently too expensive for widespread use. Titled "Cost-Effectiveness of Esketamine Nasal Spray for Patients With Treatment-Resistant Depression in the United States," the paper was published on July 7 in Psychiatric Services.

The study compared the costs and benefits of esketamine, an antidepressant approved by the U.S. Food and Drug Administration (FDA) last year for use in treatment-resistant major depressive disorder. Unlike ketamine, a drug delivered intravenously to treat severe depression, esketamine is a nasal spray.

Lead author Eric L. Ross, MD, reported that "most medications don't work as well for people with treatment-resistant depression." However, he said, "Esketamine has been effective in a population where many other treatments haven't worked."

Ross said, "I want people to use esketamine, but it's important that it be cost-effective. I don't want it to put a real strain on our mental health care system."

To estimate the cost-effectiveness of the drug, Ross and his colleagues used a "decision-analytic model" to simulate the effects of treatment with esketamine versus oral antidepressants over five years. The model looked at both societal and health care sector perspectives of using the drug.

Ross explained that the study built on previous investigations of esketamine but added information about cost. Also, he said, the model accounted for issues such as "How much does it cost to have uncontrolled depression?" and "How much does it impact your quality of life?"

The simulations found that, over five years, esketamine was projected to improve quality of life by increasing time in remission for patients. Societal costs and health care sector costs, however, were projected to go up substantially. The authors estimated a greater than 95% likelihood that intranasal esketamine would not be cost-effective in the United States, according to commonly applied standards. Also, they concluded that the price of esketamine must fall by more than 40% from its current price of approximately $240 per dose to be cost-effective for the management of treatment-resistant depression in the U.S.

"Esketamine is too expensive, but it does work," Ross asserted. "The question now is 'How do we get the price down?'"

Ross said that he hopes the paper will encourage policymakers, insurers, and health care leaders to work to reduce the price of esketamine and make it more available to those in need. "At the end of the day, it's not about saving money," he said. "The goal is to make sure we're getting the most clinical benefit we can for the money we spend."

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FUNDING: This study was supported by Research Training and Career Development grant R25-MH-094612 from the National Institute of Mental Health to Dr. Ross. The National Institute of Mental Health did not participate in the design of the study, the analysis and interpretation of the data, or the preparation and submission of the manuscript for publication. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

ABOUT McLEAN HOSPITAL: McLean Hospital has a continuous commitment to put people first in patient care, innovation and discovery, and shared knowledge related to mental health. In 2017 and 2018, it was named the #1 hospital for psychiatric care in the United States by U.S. News & World Report. McLean Hospital is the largest psychiatric affiliate of Harvard Medical School and a member of Mass General Brigham. For more information, please visit https://www.mcleanhospital.org/ or follow us on Facebook or Twitter.