Video surveillance, now for viruses

Watch a virus in the moments right before it attacks.

Peer-Reviewed Publication

DUKE UNIVERSITY

DURHAM, N.C. -- When Courtney “CJ” Johnson pulls up footage from her Ph.D. dissertation, it’s like she’s watching an attempted break-in on a home security camera.

The intruder cases its target without setting a foot inside, looking for a point of entry. But this intruder is not your typical burglar. It’s a virus.

Filmed over two and a half minutes by pinpointing its location 1,000 times a second, the footage shows a tiny virus particle, thousands of times smaller than a grain of sand, as it lurches and bobs among tightly packed human intestinal cells.

For a fleeting moment, the virus makes contact with a cell and skims along its surface but doesn’t stick before bounding off again. If this were an actual home break-in, Johnson says, “this would be the part where the burglar has not broken the window yet.”

Johnson is part of a Duke University team led by assistant chemistry professor Kevin Welsher. Together with Welsher’s postdoctoral associate Jack Exell and colleagues, they have come up with a way to capture real-time 3D footage of viruses as they approach their cellular targets.

We inhale, ingest and take in millions of viruses every day. Most of them are harmless, but some of them -- such as the viruses that cause the flu or COVID-19 -- can make us sick.

Infection starts when a virus binds to and enters a cell, where it hijacks the cellular machinery to make copies of itself.  But before it can break in, a virus has to reach the cell first, Johnson said.

That often means getting through the protective layer of cells and mucus that line the airways and the gut -- one of the body’s first lines of defense against infection.

The researchers wanted to understand how viruses breach these frontline defenses. “How do viruses navigate these complex barriers?” Welsher said. But these critical early moments before infection begins have long been difficult if not impossible to watch with existing microscopy methods, he added.

Part of the reason is that viruses move two to three orders of magnitude faster in the unconfined space outside the cell, compared with its crowded interior. To make things even trickier from an imaging perspective, viruses are hundreds of times smaller than the cells they infect.

“That's why this is such a hard problem to study,” Johnson said. Under the microscope, “it's like you're trying to take a picture of a person standing in front of a skyscraper. You can’t get the whole skyscraper and see the details of the person in front of it with one picture.”

So the team developed a new method called 3D Tracking and Imaging Microscopy (3D-TrIm), which essentially combines two microscopes in one. The first microscope “locks on” to the fast-moving virus, sweeping a laser around the virus tens of thousands of times per second to calculate and update its position. As the virus bounces and tumbles around in the soupy exterior of the cell, the microscope stage continuously adjusts to keep it in focus.

While the first microscope tracks the virus, the second microscope takes 3D images of the surrounding cells. The combined effect, Welsher said, is akin to navigating with Google Maps: it not only shows your current location as you drive, it also shows the terrain, landmarks and the overall lay of the land, but in 3D.

“Sometimes when I present this work people ask, ‘is this a video game or a simulation?’” said Johnson, now a postdoctoral associate at the Howard Hughes Medical Institute Janelia Research Campus. “No, this is something that came from a real microscope.”

With their method the researchers can’t just, say, watch a healthy person breathe in virus particles from an infected person’s cough or sneeze. For one, they have to attach a special fluorescent label to a virus before they can track it -- what the microscope follows is the movement of the glowing spot. And currently they can only track a virus for a few minutes at a time before it goes dim.

“The biggest challenge for us now is to produce brighter viruses,” Exell said.

But Welsher said he hopes the technique will make it possible to follow viruses in action beyond the coverslip, and in more realistic tissue-like environments where infections first take hold.

“This is the real promise of this method,” Welsher said. “We think that's something we have the possibility to do now.”

This work appeared online Nov. 10 in the journal Nature Methods.

This research was supported by a grant from the National Institutes of Health (R35GM124868).

CITATION: "Capturing the Start Point of the Virus-Cell Interaction With High-Speed 3D Single-Virus Tracking," Courtney Johnson, Jack Exell, Yuxin Lin, Jonathan Aguilar, and Kevin D. Welsher. Nature Methods, Nov. 10, 2022. DOI: 10.1038/s41592-022-01672-3

 

 

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JOURNAL

Nature Methods

DOI

10.1038/s41592-022-01672-3 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Capturing the Start Point of the Virus-Cell Interaction With High-Speed 3D Single-Virus Tracking

ARTICLE PUBLICATION DATE

10-Nov-2022

Economic interests cloud hazardous chemicals reductions

Peer-Reviewed Publication

UNIVERSITY OF GOTHENBURG

The regulation of hazardous chemicals in Europe has been shaped by economic interests, according to a study published in Nature Communications. The researchers, from the University of Gothenburg and Chalmers University of Technology, find that regulators focus on chemicals of secondary importance leading to lesser than anticipated hazard reductions.

“We show that the most important factor in whether a substance is subjected to binding limitations and conditions is whether it is being produced in, or imported into, the European Economic Area. The regulators are less likely to list a substance as hazardous in the Candidate List of substances of very high concern if it affects the economic interests of European firms”, says Jessica Coria, Associate Professor in Economics.

Estimates by the European Environment Agency suggest that 62 percent of the volume of chemicals consumed in Europe in 2016 were hazardous to human health, with the potential to cause a broad range of diseases. 

In the European Union, the REACH regulation (Registration, Evaluation, Authorization, and Restriction of Chemicals) has the explicit aim of ensuring a high level of protection for human health and the environment. Through the Authorization program, the manufacture and use of substances of very high concern, which may have serious effects on human health and the environment, can be subjected to binding limitations and conditions, including complete prohibitions.

The route to authorization starts with the listing of substances on the Candidate List, where member states or the European Chemical Agency propose substances for inclusion. Chemicals included on the list undergo then a prioritization process to be included on the Authorization List.

In their study in Nature Communications, researchers Jessica Coria, Erik Kristiansson, and Mikael Gustavsson, at the University of Gothenburg and Chalmers University of Technology, investigate the relative importance of toxicological properties, economic motivations, and available scientific knowledge as drivers of inclusion on the Candidate List.

Naturally, they find that hazard reduction and available scientific evidence about the effects of the chemicals are important drivers. However, the evidence in the published paper suggests that regulators have listed chemicals of secondary importance leading to lesser than anticipated hazard reductions, either because production and imports had already ceased before the listing, or because the compound has never been produced or imported into the European Economic Area at all.

“Our study includes all chemicals in REACH and clearly shows that economic factors influence what chemicals are included on the Candidate List”, says Mikael Gustavsson.

“Even if it is not surprising that economic interests affect the selection of chemicals, the relative importance of current production or importing of the substance in the European Economic Area is somewhat surprising and calls into question the actual effect of the Candidate List in removing substances of very high concern from the market”, Erik Kristiansson adds.

The results of the study suggest that low-hanging fruit has been picked first and that it may well become increasingly difficult over time to agree on chemicals of very high concern for which there is little political opposition due to a lack of local production.

“This might require a fundamental redesign of the process to ensure that hazardousness becomes the most important driver of inclusion on the Candidate List and that hazardous chemicals produced or imported in the EEA are listed even if they affect the economic interests of European firms”, Jessica Coria says.

Read the full study in Nature Communications: https://doi.org/10.1038/s41467-022-34492-2  

Contact Information:

• Jessica Coria, Associate Professor in Economics at the School of Business, Economics and Law at the University of Gothenburg, Sweden. Corresponding Author. Email: jessica.coria@economics.gu.se, phone: +46 31-786 48 67
• Mikael Gustavsson, PhD, Department of Economics, University of Gothenburg, Sweden; and Department of Mathematical Sciences, Chalmers University of Technology/University of Gothenburg, Sweden. Email: mikael.gustavsson@chalmers.se
• Erik Kristiansson, Professor, Department of Mathematical Sciences, Chalmers University of Technology/University of Gothenburg, Sweden. E-mail: erik.kristiansson@chalmers.se, phone: +46 31-772 35 21

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JOURNAL

Nature Communications

DOI

10.1038/s41467-022-34492-2 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Economic interests cloud hazard reductions in the European regulation of substances of very high concern

ARTICLE PUBLICATION DATE

10-Nov-2022

New study describes how employee opinion impacts CEO dismissal

Peer-Reviewed Publication

STRATEGIC MANAGEMENT SOCIETY

 

IMAGE: EMPLOYEES ARE KEY INTERNAL STAKEHOLDERS OF ORGANIZATIONS AND ARE CRITICAL TO THEIR SUCCESS. view more 

CREDIT: STRATEGIC MANAGEMENT SOCIETY

Corporate governance decisions, like CEO dismissal, can disrupt organizations. As a result, the board of directors treads with caution while making such decisions. Previous research suggests that boards rely on factors like financial performance and security analyst recommendations to decide on CEO dismissal. A new study published in the Strategic Management Journal in October suggests that employees’ opinions of a CEO are also likely to influence the board’s decision on CEO dismissal.

“Using financial performance and security analyst recommendations as assessment criteria for a CEO’s leadership has limitations,” says Danni Wang, one of the study’s authors who serves as an assistant professor of management and global business at Rutgers University. “Firm performance does not fully reflect a CEO’s leadership as it can be influenced by factors beyond the CEO’s control, and security analyst recommendations may be biased or based on an external perspective.”

Wang, along with co-authors Qi Zhu of Hong Kong Polytechnic University, Bruce J. Avolio of University of Washington, David Waldman of Arizona State University, and corresponding author Wei Shen of Arizona State University, argued that as important internal stakeholders of an organization, employees’ approval of the CEO is likely to influence the board’s decision to retain or dismiss the CEO.

“Employees possess crucial inside information about the CEO based on their experiences, and as implementers of the CEO’s strategies in the firm, their opinion of the CEO’s leadership has important consequences,” says Zhu, an assistant professor of management. “Moreover, because their job security is directly associated with the firm’s success or failure, they have an incentive to monitor the CEO’s leadership and strategies.”

The researchers also contended that employees’ opinions are more likely to influence the board’s decision when the firm’s financial performance is relatively strong, analyst recommendations are more positive, and the CEO is less powerful vis-à-vis the board.

To assess these arguments, the authors collected data on 338 firms and 1,252 firm-year observations from Glassdoor.com (an online platform) from 2010 to 2018. Application of regression analysis models to these data yielded results consistent with their hypotheses.

“We observed that employee approvals negatively influence CEO dismissal, that is, higher employee approval lowers the chances of CEO dismissal by the board,” explains Avolio, a renowned professor of management and Mark Pigott Chair in business strategic leadership.

“Moreover, we found that the negative relationship of employee approval on CEO dismissal is stronger when firm performance is more positive and analyst recommendation is less negative, and vice versa,” adds Shen, a noted researcher and professor of strategic management. “A powerful CEO, on the other hand, will weaken the effect of employee approval on dismissal decision.”

By demonstrating the effect of employee approval on CEO dismissal, these findings offer a key contribution to stakeholder theory, as well as strategic leadership and corporate governance literature. This study also reveals the boundary conditions whereby employee opinions become especially relevant for CEO dismissal.

“Employees are gaining importance as internal stakeholders, and their views on CEO approval cannot be ignored,” concludes Waldman, a professor and Dean’s Council Distinguished Scholar of management and leadership. “CEOs could do well by building a good reputation among employees. Employees should also realize their meaningful role as internal stakeholders and voice their opinion when asked to do so.”

The Strategic Management Journal (SMJ), founded in 1980, is the world’s leading mass impact journal for research in strategic management. The SMJ seeks to publish papers that ask and help to answer important and interesting questions in strategic management, develop and/or test theory, replicate prior studies, explore interesting phenomena, review and synthesize existing research, and evaluate the many methodologies used in the strategic management field.

SMJ is published by the Strategic Management Society (SMS), an association comprised of 3,000 academics, business practitioners, and consultants from 80 countries that focuses on the development and dissemination of insights on the strategic management process, as well as on fostering contacts and interchanges around the world. To find out more about SMS’s scientific and educational programs in strategic management, please visit www.strategicmanagement.net.

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JOURNAL

Strategic Management Journal

DOI

10.1002/smj.3465 

METHOD OF RESEARCH

Case study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Do employees' views matter in corporate governance? The relationship between employee approval and CEO dismissal

No sign of decrease in global CO2 emissions

Peer-Reviewed Publication

UNIVERSITY OF EXETER

Global carbon emissions in 2022 remain at record levels – with no sign of the decrease that is urgently needed to limit warming to 1.5°C, according to the Global Carbon Project science team.

If current emissions levels persist, there is now a 50% chance that global warming of 1.5°C will be exceeded in nine years.

The new report projects total global CO2 emissions of 40.6 billion tonnes (GtCO2) in 2022. This is fuelled by fossil CO2 emissions which are projected to rise 1.0% compared to 2021, reaching 36.6 GtCO2 – slightly above the 2019 pre-COVID-19 levels[1]. Emissions from land-use change (such as deforestation) are projected to be 3.9 GtCO2 in 2022.

Projected emissions from coal and oil are above their 2021 levels, with oil being the largest contributor to total emissions growth. The growth in oil emissions can be largely explained by the delayed rebound of international aviation following COVID-19 pandemic restrictions.

The 2022 picture among major emitters is mixed: emissions are projected to fall in China (0.9%) and the EU (0.8%), and increase in the USA (1.5%) and India (6%), with a 1.7% rise in the rest of the world combined.

The remaining carbon budget for a 50% likelihood to limit global warming to 1.5°C has reduced to 380 GtCO2 (exceeded after nine years if emissions remain at 2022 levels) and 1230 GtCO2 to limit to 2°C (30 years at 2022 emissions levels).

To reach zero CO2 emissions by 2050 would now require a decrease of about 1.4 GtCO2 each year, comparable to the observed fall in 2020 emissions resulting from COVID-19 lockdowns, highlighting the scale of the action required.

Land and ocean, which absorb and store carbon, continue to take up around half of the CO2 emissions. The ocean and land CO2 sinks are still increasing in response to the atmospheric CO2 increase, although climate change reduced this growth by an estimated 4% (ocean sink) and 17%  (land sink) over the 2012-2021 decade.

This year's carbon budget shows that the long-term rate of increasing fossil emissions has slowed. The average rise peaked at +3% per year during the 2000s, while growth in the last decade has been about +0.5% per year.

The research team – including the University of Exeter, the University of East Anglia (UEA), CICERO and Ludwig-Maximilian-University Munich – welcomed this slow-down, but said it was "far from the emissions decrease we need".

The findings come as world leaders meet at COP27 in Egypt to discuss the climate crisis.

"This year we see yet another rise in global fossil CO2 emissions, when we need a rapid decline," said Professor Pierre Friedlingstein, of Exeter's Global Systems Institute, who led the study.

"There are some positive signs, but leaders meeting at COP27 will have to take meaningful action if we are to have any chance of limiting global warming close to 1.5°C. The Global Carbon Budget numbers monitor the progress on climate action and right now we are not seeing the action required.”

Professor Corinne Le Quéré, Royal Society Research Professor at UEA’s School of Environmental Sciences, said: "Our findings reveal turbulence in emissions patterns this year resulting from the pandemic and global energy crises.

"If governments respond by turbo charging clean energy investments and planting, not cutting, trees, global emissions could rapidly start to fall.

"We are at a turning point and must not allow world events to distract us from the urgent and sustained need to cut our emissions to stabilise the global climate and reduce cascading risks."

Land-use changes, especially deforestation, are a significant source of CO2 emissions (about a tenth of the amount from fossil emissions). Indonesia, Brazil and the Democratic Republic of the Congo contribute 58% of global land-use change emissions.

Carbon removal via reforestation or new forests counterbalances half of the deforestation emissions, and the researchers say that stopping deforestation and increasing efforts to restore and expand forests constitutes a large opportunity to reduce emissions and increase removals in forests.

The Global Carbon Budget report projects that atmospheric CO2 concentrations will reach an average of 417.2 parts per million in 2022, more than 50% above pre-industrial levels.

The projection of 40.6 GtCO2 total emissions in 2022 is close to the 40.9 GtCO2 in 2019, which is the highest annual total ever.

The Global Carbon Budget report, produced by an international team of more than 100 scientists, examines both carbon sources and sinks. It provides an annual, peer-reviewed update, building on established methodologies in a fully transparent manner. Once published, the 2022 edition (the 17th annual report) will be online here: https://doi.org/10.5194/essd-14-4811-2022

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[1] These estimates include the cement carbonation sink of 0.8 GtCO2 per year

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JOURNAL

Earth System Science Data

DOI

10.5194/essd-14-4811-2022 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Global Carbon Budget 2022

ARTICLE PUBLICATION DATE

10-Nov-2022

Balancing emissions, health, and

equality in India’s expanding energy

sector

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

India needs to consider climate change and the health impacts of air pollution as the nation plans its growing future electricity infrastructure, Shayak Sengupta and colleagues argue in a new study. The findings of the analysis, which compares emissions from India’s rapidly growing energy sector and the various impacts and implications of climate change and air pollution policy interventions, show that current widely applied policies are insufficient to cut emissions or reduce air quality inequities nationwide. India is the world’s third largest economy and power producer, yet large segments of the population still do not consume electricity. As a result, electricity demand is expected to increase drastically over the next decade as this population becomes more affluent and energy infrastructure expands. However, even now, emissions from India’s current energy sector – which is currently heavily reliant on coal – are not only contributors to global climate change but also air pollution. Nearly all of India is subject to outdoor air pollution, resulting in nearly a million premature deaths annually. India’s impact on global climate and public health is projected to grow unless significant changes are made to its rapidly expanding energy sector. Sengupta et al. developed a model of Indian power generation and demand, which also assesses the impact of various policy interventions, including carbon taxes, balancing electricity generation and consumption across the country, and sulfur-control regulations. According to the findings, without new investments in low-carbon energy infrastructure, policy interventions alone are unlikely to have any real impact on India’s total emissions and are likely to cause disparate inequities in energy cost and air pollution exposure across different regions. “As India continues to develop its economy, balancing the near-term and long-term effects of its electricity sector policies, as well as their impact on social inequalities, will be critical to ensure a low-carbon transition that is green as well as just,” write Ranjit Deshmukh and Sushanta Chatterjee in a related Perspective.

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JOURNAL

Science

DOI

10.1126/science.abh1484 

ARTICLE TITLE

Subnational implications from climate and air pollution policies in India’s electricity sector

ARTICLE PUBLICATION DATE

11-Nov-2022

UK NEO-COLONIZATION

Urgent need for increase in visa cap for international doctors

Peer-Reviewed Publication

SAGE

There is an urgent need to increase the cap on visas to allow more international medical graduates to work and train in the NHS. A paper published today by the Journal of the Royal Society of Medicine outlines how increasing the cap could help address exceptionally difficult workforce issues facing the health service.

The impact of Brexit on European-origin doctors working in the NHS and the fall-out from the junior doctors’ contract disputes have resulted in many taking career breaks, leaving medicine or the UK altogether.

Co-author of the paper Dr Fraz Mir, Head of School of Medicine, Health Education East of England, said: “The promise of hundreds of extra home-grown doctors will not materialise for a number of years and even then, external support will in all certainty continue to be required.”

A scheme launched in 2009, the Medical Training Initiative (MTI), provides what the authors describe as a cost-effective and more favourable mechanism of temporarily recruiting more doctors compared to expensive locum appointments.

It provides the opportunity for highly qualified international medical graduates, primarily from South Asia and Africa, who have broadly similar medical training programmes to the UK, to spend up to two years in an NHS training post.

Run by Health Education England on behalf of the Department of Health, the scheme operates under the auspices of a sponsored Tier 5 visa (temporary work government authorised exchange visa), with a 1,500 cap across all specialties. It is linked to a formally approved training post, time-limited to a maximum of two years, preventing ‘brain-drain’ from countries that are not as well-resourced as the UK. In addition, care is taken to ensure that MTI posts do not disadvantage the learning opportunities for UK-based trainees.

To qualify, candidates must hold appropriate medical qualifications and have reached a satisfactory standard in the English language. They must also have been in clinical practice for three out of the last five years, including at least the last one year in the speciality in which they want to train in the UK.

The aim of the scheme is to provide mutual benefit to both the international doctors and the NHS, ultimately benefiting patients in both countries and forming lasting links. By attracting highly qualified doctors, the scheme also allows international doctors to share their experiences and expertise with UK colleagues.

Dr Mir said: “International medical graduates often have a valuable understanding of doing ‘more with less’ in clinical settings, expertise in tropical medicine, toxicology, infectious diseases and experience in dealing with higher volumes of patients. The concept of ‘generalism’ in medicine and surgery as well as same day emergency care is the norm in countries like India and Nigeria and something from which the UK could learn.”

Given the current workforce circumstances, he said, it is likely that the importance of the MTI scheme will increase. Consequently, an increase in the cap for Tier 5 visas is urgently needed.

Dr Mir added: “Longer term, a reciprocal arrangement for UK trainees to gain clinical and academic experiences abroad would be welcome. Building stronger research links via the MTI scheme, especially in epidemiology and public health, is likely to be of significant benefit too.”

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JOURNAL

Journal of the Royal Society of Medicine

DOI

10.1177/01410768221127415 

ARTICLE TITLE

The Medical Training Initiative: much more than learn, earn and return

ARTICLE PUBLICATION DATE

11-Nov-2022

Maintaining masking requirements at Boston Public Schools protected students, staff

Districts that lifted masking requirements saw significant increases in COVID-19 cases among students and staff, compared to Boston

Peer-Reviewed Publication

HARVARD T.H. CHAN SCHOOL OF PUBLIC HEALTH

Boston, MA – The lifting of masking requirements in school districts outside of Boston in February 2022 was associated with an additional 44.9 COVID-19 cases per 1,000 students and staff in the 15 weeks after the statewide masking policy was rescinded. This represented nearly 12,000 total COVID-19 cases or 30% of all cases in those school districts that unmasked during that time, according to a new study led by Harvard T.H. Chan School of Public Health, the Boston Public Health Commission, and Boston University School of Public Health.

“Our study shows that universal masking is an important strategy to reduce transmission in schools and one that should be considered in mitigation planning to keep students and staff healthier and minimize loss of in-person school days,” said [CT1] [DT2] Tori Cowger, corresponding author and Health and Human Rights fellow in the FXB Center for Health and Human Rights at Harvard Chan School. “Our results also suggest that universal masking may be an important tool for mitigating structural inequities that have led to unequal conditions in schools and differential risk of severe COVID-19, educational disruptions, and health and economic effects of secondary transmission to household members.”

The study was published online in the New England Journal of Medicine, Nov. 9, 2022.

When Massachusetts rescinded its statewide universal masking policy earlier this year, many schools in the state, including those in the greater Boston area, lifted their requirements over the next several weeks. However, two school districts—Boston and Chelsea—maintained universal masking policies through June. That staggered lifting of masking requirements gave the researchers the unique opportunity to examine the impact of lifting those requirements on the incidence of COVID-19 among students and staff across 72 school districts in the greater Boston area.

The researchers found that before the statewide masking requirements were lifted, the trends in the incidence of COVID-19 observed in the Boston and Chelsea school districts were similar to the trends in the districts that later lifted masking requirements. After the statewide policy was rescinded, the trends diverged, with a substantially higher incidence observed in districts that lifted masking requirements compared to districts that maintained their masking requirements.

The findings also showed that the effect of school masking policies was greatest during periods when COVID-19 incidence was highest in surrounding cities and towns, suggesting that implementing universal masking policies during times of high transmission would be most effective.

“This study provides clear support for the importance of universal masking to reduce transmission of COVID-19 in school settings, especially when community COVID levels are high,” said study co-author Eleanor Murray, assistant professor of epidemiology at Boston University School of Public Health. “Masking reduces COVID-19 transmission in schools in an equitable and easy to implement way and should be part of any layered mitigation strategy.”

“Lifting Universal Masking in Schools—Covid-19 Incidence among Students and Staff,” Tori J. Cowger, Eleanor J. Murray, Jaylen Clarke, Mary T. Bassett, Bisola O. Ojikutu, Sarimer M. Sánchez, Natalia Linos, Kathryn T. Hall, NEJM, online Nov. 9, 2022, doi: 10.1056/NEJMoa2211029

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Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people’s lives—not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America’s oldest professional training program in public health.

About Boston University School of Public Health
Founded in 1976, 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.

JOURNAL

New England Journal of Medicine

DOI

10.1056/NEJMoa2211029 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Lifting universal masking in schools—Covid-19 incidence among students and staff

ARTICLE PUBLICATION DATE

9-Nov-2022

A new air purification strategy might reduce the risk of COVID-19 transmission in classrooms and other indoor spaces by as much as tenfold

Peer-Reviewed Publication

UNIVERSITY OF SOUTHERN CALIFORNIA

University classrooms are forums for intellectual exchange. But the COVID-19 pandemic has highlighted how important it is for classrooms to also be sites of efficient air exchange—that is, good ventilation.

Air sampling technology developed by Constantinos Sioutas, a professor at the USC Viterbi School of Engineering, helped pave the way for the understanding that COVID-19 is an airborne virus. When the virus is exhaled in small respiratory droplets in indoor environments, the water content quickly evaporates because of the much lower relative humidity indoors than outdoors, leaving viral particles suspended in the air. That insight, in turn, led to the knowledge that replacing indoor air with fresh or filtered outdoor air (aka “air exchange”) can help dissipate viral particles that would otherwise linger for hours.

Now, a new study by Sioutas and his team conducted in USC classrooms demonstrates that high-efficiency in-line filters within HVAC systems can significantly improve indoor air quality. The study, published in the International Journal of Environmental Research and Public Health, also reveals that operating such a system at the same time as a portable air purifier with a HEPA filter can maximize the removal of tiny airborne particles.

Running these filtration systems simultaneously, “You reduce the risk of the students and the professor becoming infected [with COVID-19] by more than tenfold,” says Sioutas, Fred Champion Professor and Professor of Civil and Environmental Engineering and Aerospace and Mechanical Engineering.

The study’s implications extend well beyond USC to other educational institutions, as well as to residences, businesses and public transportation.

When Sioutas’ team began planning the research in the summer of 2021, they used data from USC Facilities Planning and Management (FPM) to determine which classrooms to evaluate. They wanted to measure indoor air quality across a range of building ages, classroom sizes and ventilation systems.

For the study, Sioutas’ team selected nine classrooms in seven different buildings, all of which had HVAC systems with MERV-14 in-line filters—except for one, which had a MERV-13 filter. MERV stands for the Minimum Efficiency Reporting Value; the higher the MERV rating, the more efficient the filter is in capturing particles from the air.

Eye-popping results

Sioutas was interested in measuring the effect of ventilation and filtration not only on pollutants we exhale, including carbon dioxide (CO2), but also on particulate matter (PM) that can infiltrate indoors and negatively impact human health. Indoor air pollution causes almost 3.8 million premature deaths annually, according to the World Health Organization (WHO).

His team first evaluated air quality in the nine classrooms during two-hour lectures, while students were present and the ventilation systems were operating. It turned out that all of the ventilation systems had high enough air exchange rates to dilute indoor CO2 concentrations to safe levels recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). But when it came to reducing PM and particulate number (PN) concentrations, ventilation systems with MERV-14 filters were far superior to the one with the MERV-13 filter. The former reduced PM and PN concentrations by more than 80 percent, while the latter reduced them to 49 percent and 55 percent, respectively.

Next, Sioutas’ team repeated the air quality measurements while concurrently operating a portable air purifier. When Sioutas saw the first results, he was incredulous. Within 15 minutes, PM and PN were reduced to less than 10 percent of their initial values. In some classrooms, he says, the aerosol concentrations approached those of a semiconductor-industry cleanroom, which is a factory where PM is stringently controlled to facilitate the manufacture of silicon wafers into semiconductor chips.

Sioutas figured there must have been some mistake in the calculations. “I told my students, ‘Go back and do this experiment again—these results cannot be right,’” he says. But the results held. “That’s when we realized that once you activate the purifier…you have this drastic reduction in the pollution.”

In the second part of the study, Sioutas and his team introduced an indoor source of air pollution—nebulized sodium chloride particles, which were roughly the same size as exhaled COVID-19 particles—to an empty classroom. Operating the ventilation system along with the air purifier at its highest speed reduced the concentration of sodium chloride in the air to less than 10 percent of its initial value in about 15 minutes. Since the risk of airborne virus transmission is directly proportional to an indoor space’s viral aerosol concentration, the results suggest a more than tenfold reduction in COVID-19 risk.

Air purifiers with HEPA filters work by forcing air through fine mesh made of plastic or fiberglass fibers that capture tiny particles. Since COVID-19 cannot survive on most solid surfaces for long periods, the viral particles trapped on the filter die off, posing no further risk.

Sioutas hopes that the study draws renewed attention to the importance of air purification in COVID-19 prevention in educational institutions. He notes that portable air purifiers are an effective, affordable and energy-efficient way to slash the risk of COVID-19 transmission not just in classrooms, but in any indoor environment: “homes, restaurants, pubs, movie theaters, office buildings, sports arenas, you name it,” he says.

“I’m a fierce advocate of using this technology,” he adds. “I could not recommend it more strongly.”

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JOURNAL

International Journal of Environmental Research and Public Health

DOI

10.3390/ijerph192114558 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms

ARTICLE PUBLICATION DATE

7-Nov-2022

2400 new eyes on the sky to see cosmic rainbows

Reports and Proceedings

NATIONAL INSTITUTES OF NATURAL SCIENCES

 

IMAGE: THE NEW INSTRUMENT FOR CAPTURING COSMIC RAINBOWS MOUNTED ON THE TOP OF THE SUBARU TELESCOPE. view more 

CREDIT: KAVLI IPMU

The Subaru Telescope successfully demonstrated engineering first light with a new instrument that will use about 2400 fiberoptic cables to capture the light from heavenly objects. Full operation is scheduled to start around 2024. The ability to observe thousands of objects simultaneously will provide unprecedented amounts of data to fuel Big Data Astronomy in the coming decade.

In addition to cameras, astronomers also use instruments known as spectrographs to study celestial object. A spectrograph breaks the light from an object into its component colors, in other words it creates a precise rainbow. Studying the strengths of the different colors in the rainbow from an object can tell astronomers various details about the object such as its motion, temperature, and chemical composition.

This new instrument, called PFS (Prime Focus Spectrograph), breaks visible light rainbows into two components: the red side and the blue side. So it might be more correct to refer to the data sets as half-rainbows. Combined with a third kind of detector which can see the infrared light invisible to humans, that makes one-and-a-half rainbows for an object studied with all three types of detectors.

Together with a widefield camera (HSC: Hyper Suprime-Cam), PFS will help launch the Subaru Telescope 2.0 project which will reveal the nature of dark matter and dark energy, structure formation in the Universe, and the physical processes of galaxy formation and evolution.