Tuesday, April 19, 2022

A ‘greener’ alternative for red-colored smoke

AMERICAN CHEMICAL SOCIET

The red smoke of a flare on a roadway warns motorists to be cautious, but the anthraquinone dyes currently used to produce this smoke are thought to be harmful to human health. Now, researchers reporting in ACS Sustainable Chemistry & Engineering have identified a less toxic, “greener” alternative — an organic dye called pigment red 254 (PR254). It also forms a red-colored smoke cloud more effectively than current dyes, the researchers say.

Commercialized in 1986, diketopyrrolopyrrole (DPP) dyes are used as colorants in car paints (such as the famous “Ferrari red”), optics technologies and other applications. For the purpose of signal smokes, Vojtech Pelikan and colleagues chose the DPP dye PR254, which has a brilliant red color and is less toxic than anthraquinone dyes. In experiments, the researchers showed that a PR254-containing pyrotechnic composition reached a yield of red-colored smoke of 51%, compared with only 48% for the usual anthraquinone dye. PR254 was also more thermally stable than the reference dye, which might allow it to be used in a less toxic heat-generating system, according to the researchers.

The authors acknowledge funding from the University of Pardubice.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

JOURNAL

ACS Sustainable Chemistry & Engineering

DOI

10.1021/acssuschemeng.2c01000

ARTICLE TITLE

Diketopyrrolopyrrole — A Greener Alternative for Pyrotechnic Smoke Compositions”

Study predicts thawing of gas-saturated permafrost around oil and gas wells of Russian Arctic

Peer-Reviewed Publication

SKOLKOVO INSTITUTE OF SCIENCE AND TECHNOLOGY (SKOLTECH)

Skoltech scientists and their partners from Sergeev Institute of Environmental Geoscience of RAS, with support from the R&D unit of TotalEnergies, have predicted how oil and gas wells heat up the permafrost around them. Presented in Geosciences, the new model encompasses 30 years of well operation and accounts for not just the melting of ice in frozen soil but also the gradual release of methane locked up in it. Understanding these processes is becoming increasingly relevant for accident-proof extraction and greenhouse gas emission monitoring as oil companies shift their attention to deposits in the Arctic region.

Oil and gas deposits in the Arctic region lie beneath a 100-to-500-meter layer of permafrost. As comparatively hot hydrocarbons rise up along the well shaft drilled in the frozen soil, it heats up. This causes the surrounding permafrost to thaw, compromising its ability to support structures, including the well itself. Moreover, if the frozen soil is saturated with methane, which is typical for the northern part of Western Siberia and the Yamal Peninsula in particular (Russia’s major oil and gas companies such as Gazprom and Novatek are active there), the thawing permafrost releases methane — a potent greenhouse gas and a fire hazard.

The first author of the study, Skoltech Leading Research Scientist Evgeny Chuvilin commented on the findings: “We modeled thawing around a production well that operates on the Yamal Peninsula, but similar processes can occur elsewhere and on other types of oil and gas wells, because by definition, hydrocarbons rising up from the depths carry heat: Every time you go 100 meters deeper, things heat up by about 3 degrees Celsius. With extremely deep drilling, oil can get as hot as 100 C or more.”

The model proposed by the team shows how the permafrost surrounding an active well gradually heats up and thaws, but there’s more to it. Chuvilin added: “We looked at the case with permafrost that is more complexly structured: At the depth of between 60 and 120 meters, it contains gas hydrate inclusions — icelike solids made up of frozen water and natural gas locked up in it. They are stable within a certain range of temperatures and pressures, but when these conditions are disrupted, they decompose, releasing about 170 liters of free gas per liter of solid gas hydrate. We have shown that operating one gas well for 30 years may melt the surrounding permafrost in a 10-meter radius, releasing up to 500,000 cubic meters of methane into the atmosphere.”

The team stresses that correct predictions of the well-permafrost thermal interactions are necessary for preventing critical ground depressions and cave-ins, which in turn may result in flooding and disrupt well shaft stability, potentially resulting in major repair costs. As for the emission of methane, that aspect is important for two reasons. First, that combustible gas may create the risk of fires or explosions, which might ruin the well and lead to substantial economic loss. Second, methane is a potent greenhouse gas whose release into the atmosphere needs to be monitored so that researchers could understand global and regional climate change better.

*****

Skoltech is a private international university located in Russia. Established in 2011 in collaboration with the Massachusetts Institute of Technology (MIT), Skoltech is cultivating a new generation of leaders in the fields of science, technology, and business, conducting research in breakthrough fields, and promoting technological innovation with the goal of solving critical problems that face Russia and the world. Skoltech is focusing on six priority areas: artificial intelligence and communications, life sciences and health, cutting-edge engineering and advanced materials, energy efficiency and ESG, photonics, advanced studies. Website: https://www.skoltech.ru/.

JOURNAL

Geosciences

DOI

10.3390/geosciences12030115

ARTICLE TITLE

Simulating Thermal Interaction of Gas Production Wells with Relict Gas Hydrate-Bearing Permafrost

Perception matters: How fear about crime impacts presidential approval

Whites, Blacks hold different parties accountable for crime, research shows

Peer-Reviewed Publication

WASHINGTON UNIVERSITY IN ST. LOUIS

Only one in three Americans, or 36%, approve of President Joe Biden’s handling of crime, according to a December 2021 poll by ABC News and Ipsos. An ABC News story tied the low approval to “historic jumps” in the nation’s murder rates. However, new research from Washington University in St. Louis suggests that other less objective factors may be contributing to Biden’s low approval rating.

The research, published in Public Opinion Quarterly, offers a more nuanced understanding of how anxiety about crime, race and the president’s political party influence whether Americans hold presidents accountable for crime.

Using Gallup survey data from 2000-2019 spanning across four presidential administrations — Clinton, Bush, Obama and Trump — Washington University researchers found that objective measures of state and local crime did not influence presidential approval, which is consistent with previous work in other disciplines.

However, they did find evidence that anxiety about crime — or one’s belief that crime has gotten worse in the U.S. — is a significant predictor of presidential approval. Individuals who were worried about crime in their communities were more likely to punish presidents for it. The data also showed that crime anxiety is associated with socioeconomic and demographic characteristics as well as past victimization. White people, those with higher levels of education and individuals with higher incomes were less likely to be worried about crime.

This penalty is not applied evenly, though. The data showed that white and Black respondents hold different parties accountable for crime, which researchers labeled “racially conditioned issue ownership.” In particular:

Black respondents who are anxious about crime punish Republican presidents (Bush, Trump) more harshly than Democratic presidents (Clinton, Obama). Specifically, Black respondents who are anxious about crime are 19% less likely to approve of Republican presidents. Black respondents reported no significant difference in approval for Democratic presidents, though.
White respondents who are anxious about crime do the opposite — punishing Democratic presidents more than Republican presidents. White respondents were 14% less likely to approve of Democratic presidents if they were anxious about crime. But they did not translate that anxiety into disapproval of Republican presidents.

“While whites may view Republican promises of ‘law and order’ and ‘tough-on crime’ policies as reassuring, Black Americans take a different view,” said Andrew Reeves, professor of political science in Arts & Sciences at Washington University in St. Louis and incoming director of the Weidenbaum Center on the Economy, Government, and Public Policy.

Reeves

“For Black Americans, this policy approach may evoke feelings of persecution, threats to civil rights and biased treatment by the criminal justice system. Blacks may be more likely to link concern over crime to failed or misguided policies by Republican presidents.”

Benjamin Noble, a political science PhD student at Washington University, and Steven Webster, assistant professor of political science at Indiana University, co-authored the research with Reeves.

Issue ownership, presidential approval

U.S. presidents are held accountable for a number of issues, including the economy, natural disasters, war and crime. Ownership of an issue shields presidents from punishment, said Reeves, whose research focuses on political accountability and public policy in the United States.

When presidents demonstrate their ownership of an issue — through rhetoric and/or policy decisions — they are less likely to be punished regardless of the outcome. The opposite is also true. When the incumbent’s party does not own an issue, such as crime, voters will punish the president for perceived failures in addressing the issue.

‘Like so much in American politics, race shapes perceptions of which party is superior at addressing crime.’
Benjamin Noble

Crime is a nonpartisan issue that the majority of Americans say is a “very big problem,” despite the fact that actual crime rates have halved over the last two decades, according to Noble.

Not surprisingly, U.S. presidents frequently talk about crime, take actions to address it and list crime efforts among their top accomplishments. Republicans — with their “tough on crime” policies — have long held an advantage on this issue. The data shows the story is not so simple, though.

“Like so much in American politics, race shapes perceptions of which party is superior at addressing crime,” Noble said.

“Democratic solutions that are labeled ‘soft’ by white Americans may be seen as attempts to reform a system that has disproportionately affected communities of color by Blacks.”

New way of thinking about presidential accountability

To ensure the findings were the result of true racial differences in how anxiety translates into presidential approval, the researchers reanalyzed the models to include variables that capture individuals’ policy preferences about how crime should be handled, such as community investment or by increasing funding for the police and prisons. They also measured attitudes on gun laws and the death penalty. Even with these additional measures, their theory held. The data confirmed that this effect was not simply the result of partisan or racial differences in crime-related issue opinions.

Noble hopes that these findings lead other researchers to consider how issue ownership may vary by racial or other identity-based subgroups on other issues.

“Think historically racialized issues like ballot access or drug policy or gender-based issues like family leave or child care,” he said.

“As the two parties continue to polarize across various identity-based cleavages, and immigration, race and crime become increasingly salient in American politics, we believe the importance of work along these lines will only increase.”

JOURNAL

Public Opinion Quarterly

DOI

10.1093/poq/nfab074

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Crime and presidential accountability: A case of racially conditioned issue ownership

Temple research team uncovers changes in the people and places impacted by interpersonal firearm violence following COVID-19 containment measures in Philadelphia

The city experienced a rise in the percentage of mass shootings and in the proportion of women and children who were shot.

Peer-Reviewed Publication

TEMPLE UNIVERSITY HEALTH SYSTEM

(Philadelphia, PA) – Previous work by researchers at the Lewis Katz School of Medicine at Temple University into the recent surge in firearm violence across Philadelphia during the COVID-19 pandemic found that it was strongly associated with the enactment of containment measures.

Now, new research published in the journal Preventive Medicine builds on those findings by examining the people and places impacted by interpersonal firearm violence during the COVID-19 pandemic in Philadelphia.

Utilizing the Philadelphia Police Department’s registry of shooting victims from January 1, 2015, through March 31, 2021, the research team looked at the time, date, and block-level location of incidents, as well as demographic and mortality information about victims. They also examined mass shootings, which are incidents in which four or more people are shot within one hour within 100 meters (about one city block).

Following the implementation of COVID-19 containment measures in Philadelphia on March 16, 2020 (the date of non-essential business closures):

The number of people shot per quarter nearly doubled from 331 pre-containment to 541 post-containment.
The proportion of women shot increased by 39%, from 8.2% to 11.4% of all shootings.
The proportion of children shot increased by 17%, from 7.8% to 9.0% of all shootings.
Among children, there was a 13% increase in shootings from noon-11:59 p.m.
Compared to other groups, Black women were 11% more likely and Black children were 8% more likely to be shot following COVID containment.
Mass shootings increased by 53% from 3.6% of all shootings prior to containment measures to 5.5% of all shootings after containment measures were implemented.
The increase in mass shootings did not fully explain the observed changes in the people impacted by firearm violence.
Shootings were less likely to be fatal, with 17.3% of shootings resulting in death post-containment compared to a shooting fatality rate of 20.2% pre-containment.
There were increased rates of shootings in parts of Northeast, Eastern and Southwest Philadelphia and an increase in mass shootings in the Northeast.

“Our research reveals a shift in the epidemiology and an increasing severity of interpersonal firearm violence in Philadelphia after measures were put in place to contain the spread of COVID-19,” said Jessica H. Beard, MD, MPH, FACS, Assistant Professor of Surgery and Director of Trauma Research at the Katz School of Medicine and the study’s corresponding author. “Absent robust social and economic support, the containment policies likely worsened structural inequalities that already existed. Only by examining the root causes of interpersonal firearm violence and gaining a better understanding of these changes that have occurred, can we address the epidemic of gun violence in the city. From a public health perspective, solutions could include investment in public education and employment, as well as increasing access to social services and support, such as medical assistance.”

Other researchers involved in the study include Iman N. Afif (co-first author), Zoe Maher, Elizabeth D. Dauer, Thomas A. Santora, Jeffrey H. Anderson, Abhijit Pathak, Lars Ola Sjoholm and Amy J. Goldberg in the Division of Trauma and Surgical Critical Care at the Katz School of Medicine; Ariana N. Gobaud (co-first author) in the Department of Epidemiology at the Columbia University Mailman School of Public Health; Christopher N. Morrison in the Department of Epidemiology at the Columbia University Mailman School of Public Health and the Department of Epidemiology and Preventive Medicine in the School of Public Health and Preventive Medicine at Monash University in Melbourne, VIC, Australia; Sara F. Jacoby in the Department of Family and Community Health at the University of Pennsylvania School of Nursing; and Elinore J. Kaufman in the Division of Traumatology, Surgical Critical Care and Emergency Surgery at the University of Pennsylvania Perelman School of Medicine.

About the Lewis Katz School of Medicine
Founded in 1901, the Lewis Katz School of Medicine at Temple University attracts students and faculty committed to advancing individual and population health through culturally competent patient care, research, education, and service. The School confers the MD degree; MS and PhD degrees in Biomedical Science; the MA in Urban Bioethics; the MS in Physician Assistant studies; a certificate in Narrative Medicine; a non-degree post-baccalaureate program; several dual degree programs with other Temple University schools; continuing medical education programs; and in partnership with Temple University Hospital, 40 residency and fellowship programs for physicians. The School also manages a robust portfolio of publicly and privately funded transdisciplinary studies aimed at advancing the prevention, diagnosis, and treatment of disease -- with specialized research centers focused on heart disease, cancer, substance use disorder, metabolic disease, and other regional and national health priorities. To learn more about the Lewis Katz School of Medicine, please visit: medicine.temple.edu.

JOURNAL

Preventive Medicine

DOI

10.1016/j.ypmed.2022.107020

ARTICLE TITLE

The changing epidemiology of interpersonal firearm violence during the COVID-19 pandemic in Philadelphia, P

Praising essential workers — nurses, grocery workers, corrections officers — is not just a good thing, it’s critical to their recovery from burnout

Essential workers who feel public praise recover from burnout; those less visible workers (like corrections officers) who don't feel that praise don't recover well

Peer-Reviewed Publication

BRIGHAM YOUNG UNIVERSITY

Remember when all those Twitter and Instagram posts thanking front-line workers blew up after the COVID pandemic hit? Turns out those were a big deal to essential workers.

Unfortunately, not all the essential workers felt the love, and that had major negative impacts.

A new study from Brigham Young University, University of Arizona, Rider University and New York University finds essential workers who receive public praise are energized and recover in healthy ways from the stress of their jobs, while those who don’t receive that praise experience negative emotions and are more likely to drink, smoke or overeat to recover from work.

“There are a lot of people that work behind the scenes, and we don’t see them, but they do need our public gratitude,” said study author Taeya Howell, an assistant professor in BYU's Marriott School of Business. “One of the main drivers behind doing the project was to understand what public gratitude does for essential workers while also calling attention to essential workers who are less visible.”

According to the study, published this month in Social Psychological and Personality Sciences, a significant number of essential workers in less visible fields — corrections officers, sanitation workers, truck drivers — felt the public had expressed no gratitude toward them at all. The research included two main studies: a survey of 186 corrections officers in hard-hit New England states during May/June 2020 and a second survey of 376 other essential workers who had seen social media posts praising their work or the work of other essential workers.

Quotes from two essential workers paint a clear picture of the disparity between those receiving the public praise (think nurses, doctors and grocery store workers) and those who did not.

“We’re doing three times the amount of work and feel more unappreciated than before this virus,” said one corrections officer. “Sometimes I question why I’m still an officer.” Contrast that with what one nurse reported in the media as saying: “From the patients, from the families, from management, from random people on the street… They stopped to say ‘Thank you,’ and it just re-energizes you.”

The study found that despite their essentiality, many workers who are less visible to the public received little appreciation for their efforts. For example, a pilot study by the same authors found that only 3% of those surveyed thought of corrections officers when asked to list those considered essential during the pandemic. Said one corrections officer interviewed in the study: “This job is thankless… we believe that people feel that our lives are not as valuable as other first responders.”

However, those who felt seen and appreciated were more likely to engage in healthy activities associated with a positive mental state, like exercising, meditating and spending time outdoors.

Authors say the study demonstrates the importance of public gratitude for essential workers’ long-term health, well-being and, indirectly, for the quality of their work. They also said the findings are also applicable beyond COVID-19, to other future health crises and disaster situations where essential workers do critical work, as well as to routinely stressful events.

“The general public needs to be more cognizant of the fact that showing gratitude to only some essential workers (but not others) can have detrimental effects on those who don’t receive gratitude,” said study author Hee Young Kim, associate professor of management at Rider University.

Fellow study author Sarah Doyle said people should remember that expressions of gratitude are essentially free, and yet they can have a substantial impact on the well-being of essential personnel.

“From an organizational perspective, this is a pretty powerful insight because companies spend a lot of money on other programs or initiatives that are intended to improve well-being of these workers, and yet may not be positively impacting these workers in the same way that felt gratitude does,” said Doyle, assistant professor of management and organizations at the University of Arizona’s Eller College of Management.

Dr. Michael Bizzarro of Penn Medicine Behavioral Health, Nathan Pettit, an associate professor at NYU, and Sijun Kim from the University of Arizona were also co-authors on the study.

JOURNAL

Social Psychological and Personality Science

DOI

10.1177/19485506221077858

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Are We Essential, or Sacrificial? The Effects of Felt Public Gratitude on Essential Worker Recovery Activities During COVID-19

ARTICLE PUBLICATION DATE

4-Apr-2022

How air pollution alters lung tissue, increasing cancer susceptibility

Findings highlight a potential new target for preventing lung disease caused by air pollution.

Peer-Reviewed Publication

ELIFE

Inhaled FPM pulling strings of collagen to disturb the immune defence against lung cancer cells — IMAGE: INHALED FINE PARTICULATE MATTER (SHOWN HERE IN RED) PULLS STRINGS OF COLLAGEN TO DISTURB THE IMMUNE DEFENCE IN MICE WITH LUNG CANCER CELLS. THIS ACTIVITY DELAYS THE MOVEMENT OF CYTOTOXIC T-CELLS (PURPLE) AS THEY MIGRATE TOWARDS THE CANCER CELLS (GREEN) TO DESTROY THEM. view more
CREDIT: WANG ET AL. (CC BY 4.0)

Scientists have identified a mechanism that explains how fine air pollution particles might cause lung cancer, according to a study published today in eLife.

The findings could lead to new approaches for preventing or treating the initial lung changes that lead to the disease.

Tiny, inhalable fine particulate matter (FPM) found in air pollutants has been recognised as a Group 1 carcinogen and a substantial threat to global health. However, the cancer-causing mechanism of FPM remains unclear.

“Despite its potential to cause mutations, recent research suggests that FPM does not directly promote – and may even inhibit – the growth of lung cancer cells,” explains first author Zhenzhen Wang, an associate researcher at Nanjing University (NJU), Nanjing, China, who carried out the study between labs at NJU and the University of Macau where she was sponsored by a University of Macau Fellowship. “This suggests that FPM might lead to cancer through indirect means that support tumour growth. For example, some studies suggest FPM can prevent immune cells from moving to where they are needed.”

To explore this possibility, Wang and the team collected FPM from seven locations in China and studied its effects on the main immune cells that defend against tumour growth – called cytotoxic T-cells (CTLs). In mice administered with lung cancer cells that were not exposed to FPM, CTLs were recruited to the lung to destroy the tumour cells. By contrast, in the mice whose lungs were exposed to FPM, the infiltration of CTLs was delayed – potentially allowing the tumour cells to establish in lung tissue.

To investigate why the CTLs did not enter the lung as quickly in the FPM-exposed lungs, the team studied both the CTLs themselves and the lung tissue structure. They found that CTLs exposed to FPM still retained their migratory ability, but that FPM exposure dramatically compressed the lung tissue structure and the spaces that immune cells move between. There were also much higher levels of collagen – a protein that provides biomechanical support for cells and tissues. When the team studied the movement of CTLs in the mice, in lung tissue exposed to FPM, CTLs struggled to move, whereas those in the untreated tissue were able to move freely.

Further analysis of the tissue showed that the structural changes were caused by increases in a collagen subtype called collagen IV, but the team still did not know how FPM triggered this. They found the answer when they looked more closely at the structural changes to collagen IV and the enzyme responsible for making them – called peroxidasin. This enzyme drives a specific type of cross-linking that exposure to FPM was found to cause and aggravate in the lung tissue.

“The most surprising find was the mechanism by which this process occurred,” Wang says. “The peroxidasin enzyme stuck to the FPM in the lung, which increased its activity. Taken together, this means that wherever FPM lands in the lung, increased peroxidasin activity leads to structural changes in the lung tissue that can keep immune cells out and away from growing tumour cells.”

“Our study reveals a completely new mechanism by which inhaled fine particles promote lung tumour development,” concludes senior author Lei Dong, Professor at the School of Life Sciences, Nanjing University. “We provide direct evidence that proteins that stick to fine particulate matter can cause a significant and adverse effect, giving rise to pathogenic activity. Our discovery that peroxidasin is the mediator of this effect in lung tissue identifies it as a specific and unexpected target for preventing lung disease caused by air pollution.”

Media contact

Emily Packer, Media Relations Manager

eLife

e.packer@elifesciences.org

+44 (0)1223 855373

About eLife

eLife transforms research communication to create a future where a diverse, global community of scientists and researchers produces open and trusted results for the benefit of all. Independent, not-for-profit and supported by funders, we improve the way science is practised and shared. From the research we publish, to the tools we build, to the people we work with, we’ve earned a reputation for quality, integrity and the flexibility to bring about real change. eLife receives financial support and strategic guidance from the Howard Hughes Medical Institute, Knut and Alice Wallenberg Foundation, the Max Planck Society and Wellcome. Learn more at https://elifesciences.org/about.

To read the latest Cancer Biology research published in eLife, visit https://elifesciences.org/subjects/cancer-biology.

JOURNAL

eLife

DOI

10.7554/eLife.75345

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Air pollution particles hijack peroxidasin to disrupt immunosurveillance and promote lung cancer

ARTICLE PUBLICATION DATE

19-Apr-2022

Pacific Northwest wildfires alter air pollution patterns across North America

Increase in August pollution could have far-reaching health implications

Peer-Reviewed Publication

NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH

Increasingly large and intense wildfires in the Pacific Northwest are altering the seasonal pattern of air pollution and causing a spike in unhealthy pollutants in August, new research finds. The smoke is undermining clean air gains, posing potential risks to the health of millions of people, according to the study.

The research, led by scientists at the National Center for Atmospheric Research (NCAR), found that levels of carbon monoxide — a gas that indicates the presence of other air pollutants — have increased sharply as wildfires spread in August. Carbon monoxide levels are normally lower in the summer because of chemical reactions in the atmosphere related to changes in sunlight, and the finding that their levels have jumped indicates the extent of the smoke’s impacts.

“Wildfire emissions have increased so substantially that they’re changing the annual pattern of air quality across North America,” said NCAR scientist Rebecca Buchholz, the lead author. “It’s quite clear that there is a new peak of air pollution in August that didn’t used to exist.”

Although carbon monoxide generally is not a significant health concern outdoors, the gas indicates the presence of more harmful pollutants, including aerosols (airborne particulates) and ground-level ozone that tends to form on hot summer days.

The research team used satellite-based observations of atmospheric chemistry and global inventories of fires to track wildfire emissions during most of the past two decades, as well as computer modeling to analyze the potential impacts of the smoke. They focused on three North American regions: the Pacific Northwest, the central United States, and the Northeast.

Buchholz said the findings were particularly striking because carbon monoxide levels have been otherwise decreasing, both globally and across North America, due to improvements in pollution-control technologies.

The study was published this week in Nature Communications. The research was funded in part by the U.S. National Science Foundation, NCAR’s sponsor. The paper was co-authored by researchers from the University of Colorado, Boulder; Columbia University; NASA; Tsinghua University; and Colorado State University.

Increasing impacts on air pollution

Wildfires have been increasing in the Pacific Northwest and other regions of North America, due to a combination of climate change, increased development, and land use policies. The fires are becoming a larger factor in air pollution, especially as emissions from human activities are diminishing because of more efficient combustion processes in motor vehicles and industrial facilities.

To analyze the impacts of fires, Buchholz and her collaborators used data from two instruments on the NASA Terra satellite: MOPITT (Measurements of Pollution in the Troposphere), which has tracked carbon monoxide continually since 2002; and MODIS (Moderate Resolution Imaging Spectrometer), which detects fires and provides information on aerosols. They also studied four inventories of wildfire emissions, which rely on MODIS data.

The scientists focused on the period from 2002, the beginning of a consistent and long-term record of MOPPIT data, to 2018, the last year for which complete observations were available at the time when they began their study.

The results showed an increase in carbon monoxide levels across North America in August, which corresponded with the peak burning season of the Pacific Northwest. The trend was especially pronounced from 2012 to 2018, when the Pacific Northwest fire season became much more active, according to the emissions inventories. Data from the MODIS instrument revealed that aerosols also showed an upward trend in August.

To determine whether the higher pollution levels were caused by the fires, the scientists eliminated other potential emission sources. They found that carbon monoxide levels upwind of the Pacific Northwest, over the Pacific Ocean, were much lower in August — a sign that the pollution was not blowing in from Asia. They also found that fire season in the central U.S. and the Northeast did not coincide with the August increase in pollution, which meant that local fires in those regions were not responsible. In addition, they studied a pair of fossil fuel emission inventories, which showed that carbon monoxide emissions from human activities did not increase in any of the three study regions from 2012 to 2018.

“Multiple lines of evidence point to the worsening wildfires in the Pacific Northwest as the cause of degraded air quality,” Buchholz said. “It’s particularly unfortunate that these fires are undermining the gains that society has made in reducing pollution overall.”

Risks to human health

The findings have implications for human health because wildfire smoke has been linked to significant respiratory problems, and it may also affect the cardiovascular system and worsen pregnancy outcomes.

Buchholz and her co-authors used an NCAR-based computer model, the Community Atmosphere Model with a chemistry component, to simulate the movement of emissions from the Pacific Northwest fires and their impact on carbon monoxide, ozone, and fine particulate matter. They ran the simulations on the Cheyenne supercomputer at the NCAR-Wyoming Supercomputing Center. The results showed the pollutants could affect more than 130 million people, including about 34 million in the Pacific Northwest, 23 million in the Central U.S., and 72 million in the Northeast.

Although the study did not delve deeply into the health implications of the emissions, the authors looked at respiratory death rates in Colorado for the month of August from 2002 to 2011, compared with the same month in 2012 to 2018. They chose Colorado, located in the central U.S. region of the study, because respiratory death rates in the state were readily obtainable.

They found that Colorado respiratory deaths in August increased significantly during the 2012-2018 period, when fires in the Pacific Northwest — but not in Colorado — produced more emissions in August.

“It’s clear that more research is needed into the health implications of all this smoke,” Buchholz said. “We may already be seeing the consequences of these fires on the health of residents who live hundreds or even thousands of miles downwind.”

This material is based upon work supported by the National Center for Atmospheric Research, a major facility sponsored by the National Science Foundation and managed by the University Corporation for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.

About the article

Title: New seasonal pattern of pollution emerges from changing North American wildfires
Authors: Rebecca R. Buchholz, Mijeong Park, Helen M. Worden, Wenfu Tang,
David P. Edwards, Benjamin Gaubert, Merritt Deeter, Thomas Sullivan, Muye Ru,
Mian Chin, Robert C. Levy, Bo Zheng, and Sheryl Magzamen
Journal: Nature Communications

On the web: news.ucar.edu
On Twitter: @NCAR_Science

JOURNAL

Nature Communications

DOI

10.1038/s41467-022-29623-8

METHOD OF RESEARCH

Observational study

ARTICLE TITLE

New seasonal pattern of pollution emerges from changing North American wildfires

ARTICLE PUBLICATION DATE

19-Apr-2022

Scientists resurrect ancient enzymes to improve photosynthesis

Peer-Reviewed Publication

CORNELL UNIVERSITY

ITHACA, N.Y. – A Cornell University study describes a breakthrough in the quest to improve photosynthesis in certain crops, a step toward adapting plants to rapid climate changes and increasing yields to feed a projected 9 billion people by 2050.

The study, “Improving the Efficiency of Rubisco by Resurrecting Its Ancestors in the Family Solanaceae,” published April 15 in Science Advances. The senior author is Maureen Hanson, the Liberty Hyde Bailey Professor of Plant Molecular Biology in the College of Agriculture and Life Sciences. First author Myat Lin is a postdoctoral research associate in Hanson’s lab.

The authors developed a computational technique to predict favorable gene sequences that make Rubisco, a key plant enzyme for photosynthesis. The technique allowed the scientists to identify promising candidate enzymes that could be engineered into modern crops and, ultimately, make photosynthesis more efficient and increase crop yields.

Their method relied on evolutionary history, where the researchers predicted Rubisco genes from 20-30 million years ago, when Earth’s carbon dioxide (CO2) levels were higher than they are today and the Rubisco enzymes in plants were adapted to those levels.

By resurrecting ancient Rubisco, early results show promise for developing faster, more efficient Rubisco enzymes to incorporate into crops and help them adapt to hot, dry future conditions, as human activities are increasing heat-trapping CO2 gas concentrations in Earth’s atmosphere.

The study describes predictions of 98 Rubisco enzymes at key moments in the evolutionary history of plants in the Solanaceae family, which include tomato, pepper, potato, eggplant and tobacco. Researchers use tobacco as the experimental model for their studies of Rubisco.

“We were able to identify predicted ancestral enzymes that do have superior qualities compared to current-day enzymes,” Hanson said. Lin developed the new technique for identifying predicted ancient Rubisco enzymes.

Scientists have known that they can increase crop yields by accelerating photosynthesis, where plants convert CO2, water and light into oxygen and sugars that plants use for energy and for building new tissues.

For many years, researchers have focused on Rubisco, a slow enzyme that pulls (or fixes) carbon from CO2 to create sugars. Aside from being slow, Rubisco also sometimes catalyzes a reaction with oxygen in the air; by so doing, it creates a toxic byproduct, wastes energy and makes photosynthesis inefficient.

Hanson’s lab had previously tried to use Rubisco from cyanobacteria (blue-green algae), which is faster but also reacts readily with oxygen, forcing the researchers to try to create micro-compartments to protect the enzyme from oxygen, with mixed results. Other researchers have tried to engineer more optimal Rubisco by making changes in the enzyme’s amino acids, though little was known about which changes would lead to desired results.

In this study, Lin reconstructed a phylogeny – a tree-like diagram showing evolutionary relatedness among groups of organisms – of Rubisco, using Solanaceae plants.

“By getting a lot of [genetic] sequences of Rubisco in existing plants, a phylogenetic tree could be constructed to figure out which Rubiscos likely existed 20 to 30 million years ago,” Hanson said.

The advantage of identifying potential ancient Rubisco sequences is that carbon dioxide levels were possibly as high as 500 to 800 parts per million (ppm) in the atmosphere 25 million to 50 million years ago. Today, heat-trapping CO2 levels are rising sharply due to many human activities, with current measurements at around 420 ppm, after staying relatively constant under 300 ppm for hundreds of millennia until the 1950s.

Lin, Hanson and colleagues then used an experimental system developed for tobacco in Hanson’s lab, and described in a 2020 Nature Plants paper, which employs E. coli bacteria to test in a single day the efficacy of different versions of Rubisco. Similar tests done in plants take months to verify.

The team found that ancient Rubisco enzymes predicted from modern-day Solanaceae plants showed real promise for being more efficient.

“For the next step, we want to replace the genes for the existing Rubisco enzyme in tobacco with these ancestral sequences using CRISPR [gene-editing] technology, and then measure how it affects the production of biomass,” Hanson said. “We certainly hope that our experiments will show that by adapting Rubisco to present day conditions, we will have plants that will give greater yields.”

If their method proves successful, these efficient Rubisco sequences could be transferred into crops such as tomatoes, as well as those from other plant families, such as soybeans and rice.

The study was funded by the U.S. Department of Energy.

For additional information, see this Cornell Chronicle story.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.abm6871

ARTICLE TITLE

Improving the efficiency of Rubisco by resurrecting its ancestors in the family Solanaceae

ARTICLE PUBLICATION DATE

15-Apr-2022