Tuesday, March 07, 2023

Tracing 13 billion years of history by the light of ancient quasars

New evidence for rapid heating in the early universe

Peer-Reviewed Publication

ARC CENTRE OF EXCELLENCE FOR ALL SKY ASTROPHYSICS IN 3D (ASTRO 3D)

Rebecca Davies 

IMAGE: REBECCA DAVIES, view more 

CREDIT: ASTRO 3D

Astrophysicists in Australia have shed new light on the state of the universe 13 billion years ago by measuring the density of carbon in the gases surrounding ancient galaxies.

The study adds another piece to the puzzle of the history of the universe.

“We found that the fraction of carbon in warm gas increased rapidly about 13 billion years ago, which may be linked to large-scale heating of gas associated with the phenomenon known as the ‘Epoch of Reionisation’,” says Dr Rebecca Davies, ASTRO 3D Postdoctoral Research Associate at Swinburne University of Technology, Australia and lead author of the paper describing the discovery.

The study shows the amount of warm carbon suddenly increased by a factor of five over a period of only 300 million years – the blink of an eye in astronomical timescales.

While previous studies have suggested a rise in warm carbon, much larger samples – the basis of the new study – were needed to provide statistics to accurately measure the rate of this growth.

“That's what we've done here. And so, we present two potential interpretations of this rapid evolution,” says Dr Davies.

The first is that there is an initial increase in carbon around galaxies simply because there is more carbon in the universe.

“During the period when the first stars and galaxies are forming, a lot of heavy elements are forming because we never had carbon before we had stars,” Dr Davies says. “And so one possible reason for this rapid rise is just that we're seeing the products of the first generations of stars.”

However, the study also found evidence that the amount of cool carbon decreased over the same period. This suggests that there might be two different phases in the evolution of the carbon – a rapid rise while reionisation occurs, followed by a flattening out.

The research was a collaboration between: Swinburne University of Technology; the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D); INAF-Osservatorio Astronomico di Trieste; IFPU-Institute for Fundamental Physics of the Universe, Trieste; Scuola Normale Superiore, Pisa; Max-Planck - Institut für Astronomie, Heidelberg, Germany; the University of California, Riverside; Leibniz Institute for Astrophysics Potsdam (AIP); MIT Kavli Institute for Astrophysics and Space Research, Gemini Observatory and NSF’s NOIRLab, Hawai’i; and the University of Cambridge.

The Epoch of Reionisation, which took place when the universe was “only” one billion years old, was when the lights came back on after the cosmic Dark Ages following the Big Bang.

Before this the universe was a dark, dense fog of gas. But as the first massive stars formed, their light began to shine through space and reionise the cosmos. This light may have led to rapid heating of the surrounding gas, causing the rise in warm carbon observed in this study.

Studies of reionisation are vital to understand when and how the first stars formed and began producing the elements that exist today. But measurements have been notoriously difficult.

“The research led by Dr Davies was built on an exceptional sample of data obtained during 250 hours of observations on the Very Large Telescope (VLT) at the European Southern Observatory in Chile,” says Dr Valentina D’Odorico from the Italian Institute for Astrophysics, the Principal Investigator of the observational programme. “This is the largest amount of observing time assigned to a single project carried out with the X-shooter spectrograph.

“Thanks to the 8m VLT we could observe some of the most distant quasars, which act as flashlights, illuminating galaxies along the path from the early Universe to the Earth."

As the quasar light passes through galaxies in its 13-billion-year journey across the universe some photons are absorbed, creating distinctive barcode-like patterns in the light, which can be analysed to determine the chemical composition and temperature of gas in the galaxies.

This gives an historical picture of the development of the universe.

“These ‘barcodes’ are captured by detectors at the VLT’s X-Shooter spectrograph,” Dr Davies explains.

“This instrument splits the galaxy light into different wavelengths, like putting light through a prism, allowing us to read the barcodes and measure the properties of each galaxy.”

The study led by Dr Davies captured more barcodes of ancient galaxies than ever before.

“We increased from 12 to 42 the number of quasars for which we had high quality data, finally allowing a detailed and accurate measurement of the evolution of the carbon density,” says Dr D’Odorico.

This major advance was enabled by the ESO VLT, one of the most advanced telescopes on Earth, and a strategic partner of Australia.

“The study provides a legacy data set which will not be significantly improved until 30m-class telescopes comes online towards the end of this decade,” says Professor Emma Ryan-Weber, a Chief Investigator in the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) and second author of the study.

“High quality data from even earlier in the Universe will require access to telescopes like the Extremely Large Telescope (ELT) now under construction in Chile."

Astronomers are using many different types of data to build a history of the universe.

“Our results are consistent with recent studies showing that the amount of neutral hydrogen in intergalactic space decreases rapidly around the same time,” says Dr Davies.

“This research also paves the way for future investigations with the Square Kilometre Array (SKA) which aims to directly detect emission from neutral hydrogen during this key phase of the universe's history.”

Professor Ryan-Weber says the research goes to the heart of ASTRO 3D’s mission to understand the evolution of elements, from the Big Bang to present day.

“It addresses this key goal: how did the building blocks of life – in this case carbon – proliferate across the universe?

“As humans we strive to understand ‘where did we come from?’ It’s incredible to think that the barcode of those 13-billion-year-old carbon atoms were imprinted on photons at a time when the Earth didn’t even exist. Those photons travelled across the universe, into the VLT, and then were used to develop a picture of the evolution of the universe.”

ABOUT ASTRO 3D

The ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) is a $40m Research Centre of Excellence funded by the Australian Research Council (ARC) and nine collaborating Australian universities – The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, The University of Western Australia, Curtin University, Macquarie University, The University of New South Wales, and Monash University.

The paper is available at: https://doi.org/10.1093/mnras/stad294

Examining the Decline in the C IV Content of the universe over 4.3 ≲ z ≲ 6.3 using the E-XQR-30 Sample

Rebecca L. Davies1,2⋆, E. Ryan-Weber1,2, V. D’Odorico3,4,5, S. E. I. Bosman6, R. A. Meyer6,

G. D. Becker7, G. Cupani3, L. C. Keating8, M. Bischetti3, F. B. Davies6, A.-C. Eilers9„,

E. P. Farina10, M. G. Haehnelt11,12, A. Pallottini5, Y. Zhu7
1Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia 2ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
3INAF-Osservatorio Astronomico di Trieste, Via Tiepolo 11, I-34143 Trieste, Italy
4IFPU-Institute for Fundamental Physics of the universe, via Beirut 2, I-34151 Trieste, Italy
5Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
6Max-Planck-Institut fu ̈r Astronomie, Ko ̈nigstuhl 17, D-69117 Heidelberg, Germany
7Department of Physics & Astronomy, University of California, Riverside, CA 92521, USA
8Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany
9MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave., Cambridge, MA 02139, USA 10Gemini Observatory, NSF’s NOIRLab, 670 N A’ohoku Place, Hilo, Hawai’i 96720, USA
11Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
12Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
„NASA Hubble Fellow

25 January 2023

ABSTRACT

Intervening C iv absorbers are key tracers of metal-enriched gas in galaxy halos over cosmic time. Previous studies suggest that the C iv cosmic mass density (ΩC iv) decreases slowly over 1.5 ≲ z ≲ 5 before declining rapidly at z ≳ 5, but the cause of this downturn is poorly understood. We characterize the ΩC iv evolution over 4.3 ≲ z ≲ 6.3 using 260 absorbers found in 42 XSHOOTER spectra of z ∼ 6 quasars, of which 30 come from the ESO Large Program XQR-30. The large sample enables us to robustly constrain the rate and timing of the downturn. We find that ΩC iv decreases by a factor of 4.8 ± 2.0 over the ∼ 300 Myr interval between z ∼ 4.7 and z ∼ 5.8. The slope of the column density (log N ) distribution function does not change, suggesting that C iv absorption is suppressed approximately uniformly across13.2⩽logN/cm−2 <15.0.Assumingthatthecarboncontentofgalaxyhalosevolvesastheintegralofthe cosmic star formation rate density (with some delay due to stellar lifetimes and outflow travel times), we show that chemical evolution alone could plausibly explain the fast decline in ΩC iv over 4.3 ≲ z ≲ 6.3. However, the C iv/C ii ratio decreases at the highest redshifts, so the accelerated decline in ΩC iv at z ≳ 5 may be more naturally explained by rapid changes in the gas ionization state driven by evolution of the UV background towards the end of hydrogen reionization.

Key words: quasars: absorption lines – intergalactic medium – early universe

Increased hospitalizations for heart attacks, heart failure seen in older adults living near fracking sites

Peer-Reviewed Publication

UNIVERSITY OF CHICAGO MEDICAL CENTER

A new University of Chicago study examining Medicare claims found older adults living near fracking sites in Pennsylvania were more likely to be hospitalized for cardiovascular diseases than those who lived in nearby New York state, where fracking is banned. The research was published March 6 in The Lancet Planetary Health.

Prachi Sanghavi, PhD, Assistant Professor of Public Health Sciences at UChicago and senior author on the paper, said she first became interested in studying the potential health impacts of fracking in the early 2010s. This was during the peak of the unconventional natural gas development (UNGD) boom, colloquially known as “fracking.”

“There was a lot of buzz about the environmental effects of UNGD, and several documentaries were produced on the subject,” she said. “I do a lot of work with Medicare claims data, and I realized that we could use that approach to determine if there was a measurable effect on population health based on what the stories were suggesting.”

Her team collected Medicare claims data for tens of thousands of patients generated between 2002 and 2015 in both northern Pennsylvania, which experienced a fracking boom, and next-door New York state, where UNGD was banned. They found an association between the development of new fracking sites and increased rates of hospitalization for health conditions such as acute myocardial infarction, heart failure and ischemic heart disease.

“Although we can’t point to one specific part of fracking operations as the culprit, folks living near fracking sites could be affected by exposure to things like air or water pollution that often come with fracking activity,” said Kevin Trickey, first author on the study and a former research analyst in the Sanghavi lab. “Our study connects nearby fracking activity to real, serious human health outcomes, suggesting it’s not just a matter of economics or environmental sustainability — but that policymakers and residents alike should start prioritizing the health of citizens, whether drilling new wells or plugging old ones.”

Researchers have previously found elevated levels of airborne hydrocarbons and other pollutants near fracking sites, but a clear relationship between those pollutants and negative health outcomes has not yet been established. While prior studies have indicated a likelihood of this connection, this study applies statistical analysis to economics data for causal inference analysis to more directly connect UNGD to specific negative health outcomes in older adults.

In the current study, the team determined there were an additional 11.8, 21.6 and 20.4 hospitalizations for acute myocardial infarction, heart failure and ischemic heart disease, respectively, per 1,000 Medicare users than would be expected if there were no fracking in the area.

“We don’t find strong associations easily in the world,” Sanghavi said. “We’ve heard a lot of anecdotes, seen the documentaries, but it’s usually very difficult to find the connection, even when it exists. Even in cases where an individual might have an experience that seems to have a direct relationship to something like fracking, that doesn’t necessarily translate to a population health effect, and here we find that — yes, there is a measurable association with people’s health.”

The effects were not just limited to the initial phases of UNGD. The study found that the risk continued even after drilling ended, indicating that the health impacts could be connected to the byproducts of the regular functioning and production of the well.

The researchers say these results should be a call to action for communities and policy makers affected by fracking development. “This study provides additional evidence for those who think they may be experiencing exacerbated health issues as a result of fracking in their communities,” Sanghavi said. “I hope that these results can help communities and governments — who have an interest in protecting people’s health — by equipping them with more information for making an informed decision about UNGD.

“Natural gas is an important source of energy in our current infrastructure,” she continued. “One could do a cost/benefit analysis and determine that the benefits of gas extraction outweigh the health effects on local populations. But who is bearing the cost of those decisions? The communities that are most affected by this should have all of the information and be a part of the conversation.”

The study, “Hospitalizations for cardiovascular and respiratory disease among older adults living near unconventional natural gas development,” was supported by the University of Chicago and Argonne National Laboratories. Zihan Chen of the University of Chicago is also an author on the paper. The authors declare no conflicting interests.

###

About the University of Chicago Medicine & Biological Sciences

The University of Chicago Medicine, with a history dating back to 1927, is one of the nation’s leading academic health systems. It unites the missions of the University of Chicago Medical Center, Pritzker School of Medicine and the Biological Sciences Division. Twelve Nobel Prize winners in physiology or medicine have been affiliated with the University of Chicago Medicine. Its main Hyde Park campus is home to the Center for Care and Discovery, Bernard Mitchell Hospital, Comer Children’s Hospital and the Duchossois Center for Advanced Medicine. It also has ambulatory facilities in Orland Park, South Loop, Homewood and River East as well as affiliations and partnerships that create a regional network of care. UChicago Medicine offers a full range of specialty-care services for adults and children through more than 40 institutes and centers including an NCI-designated Comprehensive Cancer Center. Together with Harvey-based Ingalls Memorial, UChicago Medicine has 1,296 licensed beds, nearly 1,300 attending physicians, over 2,800 nurses and about 970 residents and fellows.

Visit UChicago Medicine’s health and science news blog at www.uchicagomedicine.org/forefront.

Twitter @UChicagoMed
Facebook.com/UChicagoMed
Facebook.com/UChicagoMedComer

 

 

World first study into global daily air pollution shows almost nowhere on Earth is safe


Study of daily ambient fine particulate matter (PM2.5) has found that only 0.001% of the global population are exposed to WHO safe levels


Peer-Reviewed Publication

MONASH UNIVERSITY

Professor Yuming Guo 

IMAGE: PROFESSOR YUMING GUO view more 

CREDIT: MONASH UNIVERSITY

In a world first study of daily ambient fine particulate matter (PM2.5) across the globe, a Monash University study has found that only 0.18% of the global land area and 0.001% of the global population are exposed to levels of PM2.5 - the world’s leading environmental health risk factor – below levels of safety recommended by Word Health Organization (WHO). Importantly while daily levels have reduced in Europe and North America in the two decades to 2019, levels have increased Southern Asia, Australia, New Zealand, Latin America and the Caribbean, with more than 70% of days globally seeing levels above what is safe.

A lack of pollution monitoring stations globally for air pollution, has meant a lack of data on local, national, regional and global PM2.5 exposure. Now this study, led by Professor Yuming Guo, from the Monash University School of Public Health and Preventive Medicine in Melbourne, Australia, and published in the prestigious journal, Lancet Planetary Health, has provided a map of how PM2.5 has changed across the globe in the past decades

The research team utilised traditional air quality monitoring observations, satellite-based meteorological and air pollution detectors, statistical and machine learning methods to more accurately assess PM2.5 concentrations globally, according to Professor Guo. “In this study, we used an innovative machine learning approach to integrate multiple meteorological and geological information to estimate the global surface-level daily PM2.5 concentrations at a high spatial resolution of approximately 10km ×10km for global grid cells in 2000-2019, focusing on areas above 15 μg/m³ which is considered the safe limit by WHO (The threshold is still arguable),” he said.

The study reveals that annual PM2.5 concentration and high PM2.5 exposed days in Europe and northern America decreased over the two decades of the study - whereas exposures increased in southern Asia, Australia and New Zealand, and Latin America and the Caribbean.

In addition, the study found that:

  • Despite a slight decrease in high PM2.5 exposed days globally, by 2019 more than 70% of days still had PM2.5 concentrations higher than 15 μg/m³.
  • In southern Asia and eastern Asia, more than 90% of days had daily PM2.5 concentrations higher than 15 μg/m³.
  • Australia and New Zealand had a marked increase in the number of days with high PM2.5 concentrations in 2019.
  • Globally, the annual average PM2.from 2000 to 2019 was 32.8 µg/m3.
  •  The highest PM2.5 concentrations were distributed in the regions of Eastern Asia (50.0 µg/m3) and Southern Asia (37.2 µg/m3), followed by northern Africa (30.1 µg/m3).
  • Australia and New Zealand (8.5 μg/m³), other regions in Oceania (12.6 μg/m³), and southern America (15.6 μg/m³) had the lowest annual PM2.5 concentrations.
  • Based on the new 2021 WHO guideline limit, only 0.18% of the global land area and 0.001% of the global population were exposed to an annual exposure lower than this guideline limit (annual average of 5 μg/m³) in 2019.

According to Professor Guo, the unsafe PM2.5 concentrations also show different seasonal patterns “included Northeast China and North India during their winter months (December, January, and February), whereas eastern areas in northern America had high PM2.5 in its summer months (June, July, and August),” he said.

“We also recorded relatively high PM2.5 air pollution in August and September in South America and from June to September in sub-Saharan Africa.”

He added that the study is important because “It provides a deep understanding of the current state of outdoor air pollution and its impacts on human health. With this information, policymakers, public health officials, and researchers can better assess the short-term and long-term health effects of air pollution and develop air pollution mitigation strategies.”

 

 

 

Frequent socialising linked to longer lifespan of older people

Social activity nearly every day seems to be most beneficial, Chinese study suggests

Peer-Reviewed Publication

BMJ

Frequent socialising may extend the lifespan of older people, suggests a study of more than 28,000 Chinese people, published online in the Journal of Epidemiology & Community Health.

Socialising nearly every day seems to be the most beneficial for a long life, the findings suggest.

In 2017, 962 million people around the globe were over 60, and their number is projected to double by 2050. Consequently, considerable attention has focused on the concept of ‘active’ or ‘successful’ ageing, an important component of which seems to be an active social life, note the researchers.

But most of the evidence for the health benefits of socialising is based on people in Western countries, with little published data on people in Asia.

To try and plug this knowledge gap, the researchers wanted to explore whether the frequency of socialising might be linked to overall survival in a relatively large group of older people living in China.

They drew on participants of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), an ongoing, prospective nationally representative study of older people living independently, which began in 1998.

Information on the frequency of socialising only started being collected in 2002, and the current study focuses on 5 separate waves of data collection up to 2018-19, involving a total of 28,563 participants with an average age of 89.

Participants were asked how often they engaged in social activities: almost every day; at least once a week; at least once a month; occasionally; and never. Information on potentially influential factors was also collected, including sex, education, marital status; household income; fruit and vegetable intake; lifestyle; and poor health.

Survival was tracked for an average of 5 years or until death.

Over the first 5 years 25,406 people said they didn’t engage in any social activities; 1379 reported doing so sometimes; 693 at least once a month; 553 at least once a week; and 532 almost daily.

During the entire monitoring period, 21,161 (74%) participants died, 15,728 of whom died within the first 5 years.

Overall, more frequent social activity was associated with significantly longer survival. The greater the frequency, the greater the likelihood of living longer. 

Up to 5 years from the start of the monitoring period standardised death rates were 18.4 per 100 people monitored for a year among those who never socialised; 8.8 among those who did so occasionally; 8.3 among those who did so at least monthly; 7.5 among those who socialised at least once a week; and 7.3 among those who did so nearly every day.

Time to death was delayed by 42% in those who socialised occasionally, by 48% in those who did at least monthly, by 110% in those who did so at least weekly, and by 87% in those who did so nearly every day, compared with those who said they never socialised.

After 5 years, the survivors included 8420 people who said they never socialised, 688 who did so occasionally, 350 who did so at least monthly, 295 who did so at least weekly, and 272 who did so nearly every day.

Standardised death rates were 6.2 per 100 people monitored for a year among those who never socialised; 4.8 among those who did so occasionally; 5 among those socialising at least once a month; 5.4 among those doing so at least once a week; and 3.6 among those who did so nearly every day.

A threshold effect was evident: only socialising nearly every day was associated with significantly longer survival in this group among whom time to death was delayed by 204%.

Factors associated with being more socially active were male sex, younger age, a higher level of education, marriage, living in a town/city and/or with relatives, and actual/self-rated good health.

When the data were further stratified by age, social activity seemed to be even more strongly associated with extended survival within the first 5 years for the oldest old, suggesting that strategies to promote the maintenance of an active social life in very old people, should be encouraged, say the researchers.

This is an observational study, so can’t establish cause. And the researchers acknowledge they weren’t able to include possible changes in socialising or health behaviours over time.

Nor is it clear exactly why socialising in older age might extend survival. The explanations mooted include enhancing healthy behaviours, such as more physical activity and a better diet. Socialising may also mitigate the impact of chronic stressors, say the researchers.

“In our study, although the association between social activity frequency and overall survival attenuated after adjusting for sociodemographic factors, socioeconomic status, healthy behaviours and several morbidities, it still remained statistically significant, which indicated that social activity participation per se was an independent predictor for overall survival in older people,” they conclude.

Sexual minority families fare as well as, and in some ways better than, ‘traditional’ ones

Parents’ sexual orientation not important determinant of children’s development

Peer-Reviewed Publication

BMJ

Sexual minority families—where parental sexual orientation or gender identity is considered outside cultural, societal, or physiological norms—fare as well as, or better than, ‘traditional’ families with parents of the opposite sex, finds a pooled data analysis of the available evidence, published in the open access journal BMJ Global Health.

Parental sexual orientation isn’t an important determinant of children’s development, the analysis shows.

The number of children in families with lesbian, gay, bisexual, transgender or queer parents has risen in recent years. But despite a shift in public attitudes, sexual minority parenting still provokes controversy, and whether parental sexual orientation affects family outcomes continues to be a matter of debate, say the researchers.

To strengthen the evidence, and find out if there were differences in outcomes between sexual minority and different sex (straight) parent families, they systematically reviewed 34 relevant studies published between January 1989 and April 2022, and carried out in countries where same sex relationships were legally recognised.

The studies were categorised into 11 main themes: children’s psychological adjustment, physical health, gender role behaviour, gender identity/sexual orientation and educational attainment; parents’ mental health and parenting stress; and parent–child relationships, couple relationship satisfaction, family functioning, social support.

A pooled data analysis of the results of 16 of the 34 studies showed that most family outcomes were similar between these two family types. And in some domains, such as child psychological adjustment—pre-schoolers, in particular—and child-parent relationships, these were actually better in sexual minority families.

“Growing up with sexual minority parents may confer some advantages to children. They have been described as more tolerant of diversity and more nurturing towards younger children than children of heterosexual parents,” explain the researchers.

But the analysis indicated that sexual minority parents didn’t outperform different parental sex families on couple relationship satisfaction, mental health, parenting stress, or family functioning.

Risk factors for poor family outcomes for sexual minority families included experiencing stigma and discrimination, inadequate social support and co-habiting rather than married parents.

“Legal marriage confers a host of protections and advantages to the couples who marry and to their children,” note the researchers. 

The results of the narrative synthesis (18 studies), showed that children who lived in sexual minority parent families were less likely to expect to identify as straight when they grew up than were children who lived in ‘traditional’ set-up families.

“There may be less gender stereotyping in minority parent families, and this effect may be positive,” suggest the researchers. “Exploration of gender identity and sexuality may actually enhance children’s ability to succeed and thrive in a range of contexts.”

They acknowledge various limitations to their findings, including that the included studies were limited to regions where same-sex relationships were legalised, and where the social climate for these families is generally favourable. 

Most of the study participants were also from gay and lesbian households and it wasn’t possible to account for potentially influential demographic factors.

But the researchers conclude that children from sexual minority families are not at a disadvantage compared with children from different sex parent families.

“One contribution of this review is the recognition that parents’ sexual orientation is not, in and of itself, an important determinant of children’s development,” they write. “Another…is that there are significant risk factors often associated with the sexual minority experience and family functioning, such as stigma, poor social support and parenting styles.” 

They add: “Policy-makers, practitioners, and the public must work together to improve family outcomes, regardless of sexual orientation.”

 

Commercial water purification system may have caused pathogen infection in 4 hospitalized patients


Peer-Reviewed Publication

AMERICAN COLLEGE OF PHYSICIANS

1. Commercial water purification system may have caused pathogen infection in 4 hospitalized patients

Abstract: https://www.acpjournals.org/doi/10.7326/M22-3306

A study of 4 cardiac surgery patients in one hospital found that they developed Mycobacterium abscessus infectionsa multidrug-resistant nontuberculous mycobacteria, potentially due to a commercial water purifier. The water purifier had been installed in the hospital to improve water palatability but was inadvertently removing chlorine from the supply lines feeding ice and water machines in the affected area of the hospital. The study is published in Annals of Internal Medicine.

Mycobacterium abscessus is a rare but well-described pathogen associated with hospital-acquired infections. Outbreaks have been attributed to contaminated water systems, including hospital plumbing, ice and water machines, humidifiers, medications, and disinfectants. M. abscessus can cause bloodstream infections, lung infections, and skin and soft tissue infections, mostly in patients with weak immune systems.

Researchers from Harvard Medical School and Brigham and Women's Hospital recounted a descriptive study of four cardiac surgery patients at Brigham and Women's Hospital who developed M abscessus infections. Three of the four infected patients died. An investigation of the hospital’s water sources revealed the presence of a genetically identical element in ice and water machines on the infected patients’ hospital floor.  The water leading to the ice and water machines in this area of the hospital was passing through a commercial water purifier with charcoal filters and ultraviolet irradiation which the investigators found was depleting chlorine levels.  This may have facilitated increased mycobacterial colonization of the ice and water machines. Mycobacteria were likely introduced into the hospital's water system via municipal water, which is often colonized with low levels of mycobacteria.

This study demonstrates the risk of unintended consequences associated with modifying water management systems in hospitals and the potential risk this can pose to patients.  It also bespeaks the importance of augmenting hospitals' water management programs to monitor and prevent mycobacteria in addition to Legionella as well as the potential value of initiatives to minimize vulnerable patients' exposure to tap ice and water during hospital care.

Media contacts: For an embargoed PDF, please contact Angela Collom at acollom@acponline.org. To speak with the corresponding author, Michael Klompas, MD, MPH, please email Jessica Pastore at jpastore@bwh.harvard.edu.

--------------------------------

2. YouTube’s credibility tags face “credibility conundrum” in fight against misinformation

Abstract: https://www.acpjournals.org/doi/10.7326/M23-0490   

URL goes live when the embargo lifts

While YouTube’s newly introduced tagging policy attempts to steer consumers to credible information sources on the social media platform by prioritizing credible sources in the search algorithm, individuals may still tend to rely on sources they trust for health information, like friends or even celebrities. The authors of a new commentary published in Annals of Internal Medicine refer to this as the “credibility conundrum.” What one person considers “credible,” another may not.

Commentary authors, Christine Laine, MD, MPH, editor-in-chief of Annals of Internal Medicine, and Hussain Lalani, MD, MPH of Brigham and Women’s Hospital and Harvard Medical School, cited a recent patient encounter as an example of the credibility conundrum. When asked why she declined COVID-19 vaccination, a 70-year-old woman said that she lived with her daughter and wanted grandchildren. A “friend who reads a lot” told her that vaccinated people shed particles that affect the fertility of those around them. Even though advice she received from clinicians contradicted advice from her friend, the patient found her friend to be a more credible source of information.

It is uncertain how tagging individuals or organizations that medical experts deem “credible” and prioritizing them in search results will influence the public’s health literacy. YouTube and its panel of medical experts recognize this challenge and have invited feedback from users and content contributors. Health professionals who observe potentially problematic posts or have ideas about how to further elevate good health information should respond to YouTube’s invitation for feedback. But the editorialists say that health care professionals should also ask their patients who seem misinformed where they get their information and attempt to direct them to credible sources.  Studies show that sources considered to be trustworthy varied substantially by political affiliation, geography, and age. Being a trusted source for patients is one way physicians can help thwart the spread of misinformation while society works to solve this conundrum.   

Media contacts: For an embargoed PDF or to speak with corresponding author, Christine Laine, MD, MPH, please contact Angela Collom at acollom@acponline.org.

--------------------------------

3. Over-the-scope-clips may be more effective than standard treatment for some patients with nonvariceal upper gastrointestinal bleeding

Abstract: https://www.acpjournals.org/doi/10.7326/M22-1783

Editorial: https://www.acpjournals.org/doi/10.7326/M23-0449

URL goes live when the embargo lifts

A randomized controlled trial of adults with active bleeding or a nonbleeding visible vessel from a nonvariceal cause on upper gastrointestinal endoscopy found that over-the-scope-clips (OTSCs) as an initial treatment may be better than standard treatment in reducing the risk for further bleeding from some nonvariceal upper gastrointestinal causes. The findings are published in Annals of Internal Medicine.

 

The current standard in endoscopic hemostasis includes the use of hemo-clips or contact thermal devices, but the failure rate with these methods may be up to 10 percent and further bleeding after endoscopic hemostasis increases mortality risk. OTSCs, which memory-shaped nitinol clips that are cap mounted onto the end of an endoscope, can be used in hemostasis. Currently, OTSCs are primarily used in severe or refractory bleeding from nonvariceal causes.

 

Researchers from several university hospitals in Hong Kong, China and Australia conducted a randomized controlled trial of 190 adult patients with active bleeding or a nonbleeding visible vessel from a nonvariceal cause on upper gastrointestinal endoscopy. Ninety-seven participants were assigned to receive standard treatment, and 93 received treatment using OTSCs. The authors found that the 30-day probability for bleeding in the standard treatment group was 14.6 percent and 3.2 percent for the OTSC group. However, while the findings suggest the use of OTSCs may be better than standard treatment in preventing further bleeding, the authors are not advocating routine primary use of OTSCs. Instead, they suggest that primary use of OTSCs may find a role in the treatment of ulcers predicted to fail standard endoscopic treatment.

 

An accompanying editorial from McGill University Health Centre supports the authors’ conclusion that their findings do not suggest that OTSCs should be used as an initial treatment for nonvariceal upper gastrointestinal bleeding. They say that while endoscopists should be trained in their use, OTSCs are also expensive compared to other therapies.  The editorialists say that OTSCs should be reserved for patients lesions at high risk for failure with standard treatments, such as those bleeding from ulcers exceeding 2 cm or located high in the gastric lesser curvature or posterior duodenal bulb.

 

Media contacts: For an embargoed PDF, please contact Angela Collom at acollom@acponline.org. To speak with the corresponding author, James Y.W. Lau, MD, please email   laujyw@surgrey.cuhk.edu.hk.

-----------------

Also new in this issue:

Self-Rated Health and Ability to Climb Stairs: A Pragmatic Health Assessment Before Lung Cancer Screening

Alison S. Rustagi, MD, PhD; Christopher G. Slatore, MD, MS; and Salomeh Keyhani, MD, MPH

Ideas and Opinions

Abstract: https://www.acpjournals.org/doi/10.7326/M22-3598

'Giant' ant fossil raises questions about ancient Arctic migrations

Peer-Reviewed Publication

SIMON FRASER UNIVERSITY

The giant fossil queen ant Titanomyrma from Wyoming 

IMAGE: THE FOSSIL EXTINCT GIANT ANT TITANOMYRMA FROM WYOMING THAT WAS DISCOVERED OVER A DECADE AGO BY SFU PALEONTOLOGIST BRUCE ARCHIBALD AND COLLABORATORS AT THE DENVER MUSEUM. THE FOSSIL QUEEN ANT IS NEXT TO A HUMMINGBIRD, SHOWING THE HUGE SIZE OF THIS TITANIC INSECT. view more 

CREDIT: BRUCE ARCHIBALD

Simon Fraser University scientists say their research on the latest fossil find near Princeton, B.C. is raising questions about how the dispersal of animals and plants occurred across the Northern Hemisphere some 50 million years ago, including whether brief intervals of global warming were at play.

The fossil was discovered by Princeton resident Beverly Burlingame and made available to the researchers through the town’s museum. Researchers say it is the first Canadian specimen of the extinct ant Titanomyrma, whose biggest species was surprisingly gigantic, with the body mass of a wren and a wingspan of half a foot.

SFU paleontologists Bruce Archibald and Rolf Mathewes, together with Arvid Aase of Fossil Butte National Monument in Wyoming, have published their research on the fossil in the current edition of the scientific journal The Canadian Entomologist.

A decade earlier, Archibald and collaborators discovered a gigantic Titanomyrma fossil from Wyoming in a museum drawer in Denver. “This ant and the new fossil from British Columbia are close in age to other Titanomyrma fossils that have been long known in Germany and England,” says Archibald. “This raises the questions of how these ancient insects traveled between continents to appear on both sides of the Atlantic at nearly the same time.”

Europe and North America were connected by land across the Arctic then, as the North Atlantic had not yet opened enough by continental drift to fully separate them. But was the ancient far-northern climate suitable for their passage?

The scientists found that the ancient climates were hot where these ants lived in Wyoming and Europe. They further found that modern ants with the biggest queens also inhabit hot climates, leading them to associate large size in queen ants with high temperatures. This creates a problem, however, as although the ancient Arctic had a milder climate than today, it still wouldn’t have been hot enough to allow Titanomyrma to pass.

New findings build on earlier research

The researchers suggested in 2011 that this might be explained by geologically brief intervals of global warming around the time of Titanomyrma called “hyperthermals” creating short-term intervals of friendly conditions for them to cross.

They then predicted that Titanomyrma wouldn’t be found in the ancient temperate Canadian uplands, as it would have been cooler than Titanomyrma appears to have required. But now one has been discovered there.

The story becomes more complicated and interesting, as the new Canadian fossil was distorted by geological pressure during fossilization, so its true life size can’t be established. It might have been gigantic like some of the largest Titanomyrma queens, but it could equally be reconstructed as smaller.

“If it was a smaller species, was it adapted to this region of cooler climate by reduction in size and gigantic species were excluded as we predicted back in 2011?” says Archibald. “Or were they huge, and our idea of the climatic tolerance of gigantic ants, and so how they crossed the Arctic, was wrong?”

Archibald says the research is helping scientists better understand how B.C.’s community of animals and plants were forming when climate was much different. “Understanding how life dispersed among the northern continents in a very different climate 50 million years ago in part explains patterns of animal and plant distribution that we see today,” says Archibald.

Titanomyrma may also help us better understand how global warming could affect how the distribution of life may change. To prepare for the future, it helps to understand the past.” 

He adds: “We’ll need to find more fossils. Do our ideas of Titanomyrma’s ecology, and so of this ancient dispersal of life, need revision? For now, it remains a mystery.”

UMass Amherst research professor teams with national weather service to build database on public response to severe weather hazards


The public is being surveyed on perceptions and response to flash floods, tornados, severe thunderstorms and winter weather under a grant from the National Oceanic and Atmospheric Administration

Grant and Award Announcement

UNIVERSITY OF MASSACHUSETTS AMHERST

Brenda Philips 

IMAGE: BRENDA PHILIPS, RESEARCH PROFESSOR AND CO-DIRECTOR OF THE UMASS AMHERST PAROS CENTER FOR ATMOSPHERIC RESEARCH view more 

CREDIT: UMASS AMHERST

AMHERST, Mass. — University of Massachusetts Amherst research professor Brenda Philips has received a grant from the National Oceanic and Atmospheric Administration (NOAA) to work with National Weather Service forecast offices across the country to ascertain the factors that influence people’s responses to severe weather events. The goal of the two-year, $396,855 grant is to build a national multi-year database on human reactions to four types of weather hazards: flash floods, tornados, severe thunderstorms and winter weather events. 

“NOAA collects lots of meteorological data, but only collects a very limited amount of data on societal response to weather and warnings,” says Philips, who has worked closely with National Weather Service (NWS) forecasters as part of her research on severe weather warning systems and as co-director of UMass Amherst’s Paros Center for Atmospheric Research (PCAR).  

“I’m excited about this surveying effort,” Philips says. “We’re launching surveys one to 14 days after medium-to-high-end events happen so we can collect detailed accounts of how people experienced a specific flood, for example. If we aggregate survey responses over many events, we’ll be able to understand better how different segments of the population experience hazards.” 

Finding out how people interpret and react to severe weather is becoming more and more important. A 2020 report from the United Nations Office for Disaster Risk Reduction found climate-related disasters have jumped 83% in the past 20 years, with major floods more than doubling and severe storms up 40%. 

“We’re seeing more dramatic flash floods and winter events due to climate change,” she says. “Everybody’s having these 100-year and 200-year floods and seeing really unusual situations. Getting a handle on how different environmental, social and situational factors influence an individual’s risk perception is very important,” she added. 

Human response varies depending on the hazard, the type of protective action they are advised to take and also the duration of the warning, Philips says. 

“A tornado warning lasts about 45 minutes. It’s very focused and you should go to a protected area, like a basement, immediately; flash flood warnings last at least two or three hours and cover a large geographic area, so drivers just have to be aware that they might encounter a flooded road,” she says. 

Under the grant Philips received from the weather program office’s social behavioral and economic sciences program, she will work with nine NWS forecast offices (Boston, Fort Worth, Pittsburgh, Atlanta, Nashville, Little Rock, Philadelphia, Portland and Phoenix) to send surveys soon after weather events to people in the affected areas. Questions address their information sources, preparations prior to the event, whether they sheltered in place in the case of a tornado, or avoided flooded roads for flash flood events.  

By the end of the grant period, Philips hopes to have sufficient responses to be able to start to understand the relative importance of key factors such as environmental cues, demographics, situational circumstances and risk communication. 

“For flash flooding, I’ve done some pilot studies, and those have shown that it’s the social cues — whether other cars are turning around — are one of the biggest influences for turning around,” she says. “Also, the current situation matters. People drive on flooded roads more often to get to work — they’re more likely to take the risk.” 

She also hopes to learn more about any racial, economic and regional factors that need to be addressed as weather offices craft warnings in the future, which could influence what channels they use to do so. 

While the weather service uses multiple channels, such as television, radio and social media, “even then, you have people who say I didn’t get the message,” she says. 

“To start to formulate policy or prioritize research on warning systems, it’s important to start with the people that NOAA is serving,” Philips added. “This research will give NOAA the tools to do that more effectively.” 

 

Contact: Brenda Philips, bphilips@engin.umass.edu 
Melinda Rose, melindarose@umass.edu