Saturday, November 25, 2023

 

Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests


Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - LOS ANGELES HEALTH SCIENCES




Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests

New research finds little evidence that post-surgical patient mortality is lower when patient and surgeon are the same gender.

While gender concordance has been shown to improve patient care in other health specialties, evidence has been limited when it comes to concordance between patient and surgeon. This study shows that gender concordance was associated with lower mortality for female patients, but higher mortality for male patients—patient mortality was the lowest for female patients treated by female surgeons, and the highest for male patients treated by male surgeons.

This study also investigated the impact of surgeon gender, and shows that female surgeons had slightly lower patient mortality than males for elective surgeries, but no gender difference for non-elective procedures.

The findings will be published in the peer-reviewed journal The BMJ.

“It is important for patients to know that the quality of surgical care provided by female surgeons in the United States is equivalent to, or in some cases, slightly better than that provided by male surgeons,” said senior author Dr. Yusuke Tsugawa, associate professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA. “Given that the difference in patient mortality between female and male surgeons was small, when choosing a surgeon, patients should take into account factors beyond the gender of the surgeon.”

The researchers examined data for 2.9 million Medicare fee-for-service beneficiaries aged 65 years and older who underwent one of 14 surgeries between 2016 and 2019: abdominal aortic aneurysm repair, appendectomy, cholecystectomy, colectomy, coronary artery bypass surgery, knee replacement, hip replacement, hysterectomy, laminectomy or spinal fusion, liver resection, lung resection, prostatectomy, radical cystectomy, and thyroidectomy.

Of the participants, 1.2 million (41%) were male surgeon/patient pairs, 86,000 (3%) were female pairs, and 1.6 million (56%) were pairs of different genders (52,000, or 1.8%, were male patient/female surgeon and 1.5 million, or 54%, female patient/male surgeon). The outcome measure was death within 30 days of the procedure.

Adjusting for patient and surgeon characteristics and other factors, the researchers found that 30 day post-surgery mortality was 2.0% for male patient-male surgeon, 1.7% for male patient-female surgeon, 1.5% for female patient-male surgeon, and 1.3% for female patient-female surgeon pairs.

Study limitations include potential undetected confounders from Medicare claims data, an inability to account for contributory characteristics of other healthcare team members, and the possibility that the findings may not apply to younger patients.

But the findings could lead to a better understanding of processes that improve care for all patients, the researchers write. “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery,” they write.

Study co-authors are Ryo Ikesu, Dr. Melinda Maggard-Gibbons, and Ruixin Li of UCLA; Christopher Wallis, Angela Jerath, Dr. Natalie Coburn, and Allan Detsky, of the University of Toronto; Raj Satkunasivam of Texas A&M University and Houston Methodist Hospital; Justin Dimick of University of Michigan; E. John Orav of Harvard University; Arghavan Salles of Stanford University; Zachary Klaassen of Georgia-Augusta University, and Barbara Bass of George Washington University.

This study was funded by the National Institute of Health (NIH)/National Institute on Minority Health and Health Disparities (R01 MD013913) and Gregory Annenberg Weingarten GRoW @Annenberg.

Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests

New research finds little evidence that post-surgical patient mortality is lower when patient and surgeon are the same gender.

While gender concordance has been shown to improve patient care in other health specialties, evidence has been limited when it comes to concordance between patient and surgeon. This study shows that gender concordance was associated with lower mortality for female patients, but higher mortality for male patients—patient mortality was the lowest for female patients treated by female surgeons, and the highest for male patients treated by male surgeons.

This study also investigated the impact of surgeon gender, and shows that female surgeons had slightly lower patient mortality than males for elective surgeries, but no gender difference for non-elective procedures.

The findings will be published in the peer-reviewed journal The BMJ.

“It is important for patients to know that the quality of surgical care provided by female surgeons in the United States is equivalent to, or in some cases, slightly better than that provided by male surgeons,” said senior author Dr. Yusuke Tsugawa, associate professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA. “Given that the difference in patient mortality between female and male surgeons was small, when choosing a surgeon, patients should take into account factors beyond the gender of the surgeon.”

The researchers examined data for 2.9 million Medicare fee-for-service beneficiaries aged 65 years and older who underwent one of 14 surgeries between 2016 and 2019: abdominal aortic aneurysm repair, appendectomy, cholecystectomy, colectomy, coronary artery bypass surgery, knee replacement, hip replacement, hysterectomy, laminectomy or spinal fusion, liver resection, lung resection, prostatectomy, radical cystectomy, and thyroidectomy.

Of the participants, 1.2 million (41%) were male surgeon/patient pairs, 86,000 (3%) were female pairs, and 1.6 million (56%) were pairs of different genders (52,000, or 1.8%, were male patient/female surgeon and 1.5 million, or 54%, female patient/male surgeon). The outcome measure was death within 30 days of the procedure.

Adjusting for patient and surgeon characteristics and other factors, the researchers found that 30 day post-surgery mortality was 2.0% for male patient-male surgeon, 1.7% for male patient-female surgeon, 1.5% for female patient-male surgeon, and 1.3% for female patient-female surgeon pairs.

Study limitations include potential undetected confounders from Medicare claims data, an inability to account for contributory characteristics of other healthcare team members, and the possibility that the findings may not apply to younger patients.

But the findings could lead to a better understanding of processes that improve care for all patients, the researchers write. “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery,” they write.

Study co-authors are Ryo Ikesu, Dr. Melinda Maggard-Gibbons, and Ruixin Li of UCLA; Christopher Wallis, Angela Jerath, Dr. Natalie Coburn, and Allan Detsky, of the University of Toronto; Raj Satkunasivam of Texas A&M University and Houston Methodist Hospital; Justin Dimick of University of Michigan; E. John Orav of Harvard University; Arghavan Salles of Stanford University; Zachary Klaassen of Georgia-Augusta University, and Barbara Bass of George Washington University.

This study was funded by the National Institute of Health (NIH)/National Institute on Minority Health and Health Disparities (R01 MD013913) and Gregory Annenberg Weingarten GRoW @Annenberg.


Death rates after surgery similar regardless of patient-surgeon gender match

Findings should help improve processes and patterns of care for all patients

Peer-Reviewed Publication

BMJ

Death rates after major surgery are similar regardless of whether a male or female surgeon operates on a male or female patient, finds a large US study published by The BMJ today.

The differences seen were small and not clinically meaningful and the researchers say their findings should help improve processes and patterns of care for all patients.

Gender concordance between patients and physicians (when the physician and patient are of the same sex) is generally linked to higher quality care processes and improved patient outcomes through more effective communication, reduced (implicit and explicit) sex and gender bias, and better rapport.

But evidence is limited about the effect of patient and surgeon gender concordance on outcomes of patients undergoing a surgical procedure.

To address this, researchers set out to determine whether patient-surgeon gender concordance is associated with death after surgery in the United States. 

Their theory was that patients treated by surgeons of the same gender would have a lower postoperative death rate than patients treated by gender discordant surgeons.

They analysed data for almost 3 million Medicare patients aged 65-99 years who underwent one of 14 common major urgent or non-urgent (elective) surgeries between 2016 and 2019 including coronary artery bypass surgery, knee or hip replacement, hysterectomy, liver or lung resection, and thyroidectomy.

Death after surgery was defined as death within 30 days of the operation.

Adjustments were made for patient characteristics (such as age, race and underlying conditions), surgeon characteristics (such as age, years in practice and number of operations performed) and hospital fixed effects (effectively comparing patients within the same hospital).

Of 2,902,756 patients who had surgery, 1,287,845 (44%) had operations done by surgeons of the same gender (1,201,712 (41%) male patient and male surgeon and 86,133 (3%) female patient and female surgeon) and 1,614,911 (56%) were by surgeons of different gender (52,944 (1.8%) male patient and female surgeon and  1,561,967 (54%) female patient and male surgeon). 

For urgent and elective procedures combined, the adjusted death rate 30 days after surgery was 2% for male patients treated by male surgeons, 1.7% for male patients treated by female surgeons, 1.5% for female patients treated by male surgeons, and 1.3% for female patients treated by female surgeons.

For elective procedures, female surgeons had slightly lower patient death rates (0.5%) than male surgeons (0.8%), whereas no difference in patient mortality was seen for urgent surgeries.

Several mechanisms could explain this small effect for elective procedures, say the authors. For example, female surgeons may abide by clinical guidelines more than male surgeons, or might have better communication and increased attention to postoperative care than male surgeons, which could affect patient death rates. 

What’s more, as elective surgeries allow patients to choose their own surgeon, they are more prone to influence from other factors compared with urgent procedures where patients are assigned to on-call surgeons, they add.

This is an observational study, so can’t establish cause, and the researchers stress that other unmeasured social and cultural factors may have influenced their results. What’s more, they say their findings may not apply to younger populations, patients who receive less common procedures, or patients in other countries.

Nevertheless, they say understanding the underlying mechanisms of this observation “allows the opportunity to improve processes and patterns of care for all patients.”

They add: “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery.”

 

€2.7 million for superconducting 'miracle'


Grant and Award Announcement

TECHNISCHE UNIVERSITÄT DRESDEN

cerium-rhodium-arsenic (CeRh2As2) 

IMAGE: 

DEPICTED IS THE SUPERCONDUCTING MIRACLE CERIUM-RHODIUM-ARSENIC (CERH2AS2). THANKS TO A €2.7 MILLION GRANT FROM THE EUROPEAN RESEARCH COUNCIL, ELENA HASSINGER WILL BE ABLE TO ADVANCE HER RESEARCH ON THIS MATERIAL AT THE CLUSTER OF EXCELLENCE CT.QMAT FOR THE NEXT FIVE YEARS.

view more 

CREDIT: JÖRG BANDMANN/CT.QMAT




Unconventional Superconductor CeRh2As2: A Quantum Superstar

The research conducted by Elena Hassinger, an expert in low-temperature physics working at ct.qmat—Complexity and Topology in Quantum Matter (a joint initiative by two universities in Würzburg and Dresden), has always been synonymous with extreme cold. In 2021, she discovered the unconventional superconductor cerium-rhodium-arsenic CeRh2As2). Superconductors normally have just one phase of resistance-free electron transport, which occurs below a certain critical temperature. However, as reported in the academic journal Science, CeRh2As2 is so far the only quantum material to boast two certain superconducting states.

Lossless current conduction in superconductors has remained a central focus in solid-state physics for decades and has emerged as a significant prospect for the future of power engineering. The discovery of a second superconducting phase in CeRh2As2, which results from an asymmetric crystal structure around the cerium atom (the rest of the crystal structure is completely symmetrical), positions this compound as a prime candidate for use in topological quantum computing. Hassinger plans to extend her search to other quantum materials with similar unusual structural properties, hoping to achieve topological superconductivity at higher temperatures.

ERC Consolidator Grant: €2.7 Million Boost from the European Research Council

The European Research Council has awarded Hassinger €2.7 million for her project “Exotic Quantum States by Locally Broken Inversion Symmetry in Extreme Conditions—Ixtreme.” Over the next five years, she intends to use this funding to further her study of the superconducting “miracle” CeRh2As2 in her Dresden laboratories, uncover related quantum materials, and contribute to a significant breakthrough in topological quantum computing. “If we can confirm the theoretical predictions of topological surface states on my cerium-rhodium-arsenic compound in the laboratory, this could pave the way for the creation of topological quantum bits (qubits). This would be a huge step forward,” Hassinger explains.

Huge Potential for Topological Quantum Computing

Topological qubits are known for their robustness, offering quantum states that are significantly more stable compared to their non-topological counterparts. One of the biggest challenges in current research is developing a method to sustain 1,000 qubits simultaneously. Achieving this would enable quantum processors to complete tasks in a matter of minutes that would take conventional supercomputers years. This is why the brilliant minds at ct.qmat are concentrating on research into topological quantum materials.

Groundbreaking Research under Extreme Laboratory Conditions

In her quest to investigate the unconventional superconductor cerium-rhodium-arsenic, Hassinger first needs a cryostat to cool the material sample to below 0.35 Kelvin (–272.8 degrees Celsius). “This machine costs over a million euros. Negotiations are already underway,” she reveals. When the sample is cold enough, it will be subjected to intense pressure and an ultra-strong magnetic field of up to 18 Tesla, vastly exceeding the 0.1 Tesla field of a typical horseshoe magnet. “Conducting these high-pressure magnetic field measurements could take several months, requiring precise daily adjustments,” Hassinger explains, outlining her experimental approach. Her goal is to closely examine the second superconducting phase of cerium-rhodium-arsenic in order to finally prove that the material is a topological superconductor. If successful, this “miracle material” would not only enable lossless electron conduction but also possess robust topological surface states that could potentially be used in quantum computing operations.

Outlook

“The European Research Council funds promising pioneering research with the ERC Consolidator Grant. Elena Hassinger is an experienced physicist who has discovered an exceptional material. With this new grant, she aims to be the first to experimentally characterize its exotic quantum states and also find related quantum states in similar materials at higher temperatures,” says Professor Matthias Vojta, ct.qmat’s Dresden spokesperson. “We’re thrilled to have her as part of our ct.qmat research family,” he adds.

About Elena Hassinger

Since the fall of 2022, Elena Hassinger has held ct.qmat’s Chair of Low-Temperature Physics of Complex Electron Systems, which is based at TU Dresden. She is also closely associated with the Max Planck Institute for Chemical Physics of Solids (MPI CPfS) in Dresden as a Max Planck Fellow. Notable achievements in her career include heading the independent research group Physics of Unconventional Metals and Superconductors at MPI CPfS since 2014 and a tenure-track professorship at TU Munich from 2016 to 2022.

Cluster of Excellence ct.qmat

The Cluster of Excellence ct.qmat—Complexity and Topology in Quantum Matter has been jointly run by Julius-Maximilians-Universität Würzburg and Technische Universität Dresden since 2019. Over 300 scientists from more than thirty countries and four continents study topological quantum materials that reveal surprising phenomena under extreme conditions such as ultra-low temperatures, high pressure, or strong magnetic fields. ct.qmat is funded through the German Excellence Strategy of the Federal and State Governments and is the only Cluster of Excellence in Germany to be based in two different federal states.

Links & Downloads
YouTube video (English language, German subtitles): „Transporting electricity without loss | #Introducing Elena Hassinger“: https://youtu.be/JC0DUsq89kw?si=i5JX1YyYoAuBELgr
Download illustration & portrait photos: https://datashare.tu-dresden.de/s/mgFoM9Qf9oAT5Qn


‘Strange metal’ is strangely quiet in noise experiment


Rice physicists find evidence of exotic charge transport in quantum material


Peer-Reviewed Publication

RICE UNIVERSITY

Douglas Natelson 

IMAGE: 

RICE UNIVERSITY PHYSICIST DOUG NATELSON.

view more 

CREDIT: (PHOTO BY JEFF FITLOW/RICE UNIVERSITY)




HOUSTON – (Nov. 23, 2023) – True to form, a “strange metal” quantum material proved strangely quiet in recent quantum noise experiments at Rice University. Published this week in Science, the measurements of quantum charge fluctuations known as “shot noise” provide the first direct evidence that electricity seems to flow through strange metals in an unusual liquidlike form that cannot be readily explained in terms of quantized packets of charge known as quasiparticles.

“The noise is greatly suppressed compared to ordinary wires,” said Rice’s Douglas Natelson, the study’s corresponding author. “Maybe this is evidence that quasiparticles are not well-defined things or that they’re just not there and charge moves in more complicated ways. We have to find the right vocabulary to talk about how charge can move collectively.”

The experiments were performed on nanoscale wires of a quantum critical material with a precise 1-2-2 ratio of ytterbium, rhodium and silicon (YbRh2Si2), which has been studied in great depth during the past two decades by Silke Paschen, a solid-state physicist at the Vienna University of Technology (TU Wien). The material contains a high degree of quantum entanglement that produces a very unusual (“strange”) temperature-dependent behavior that is very different from the one in normal metals such as silver or gold. 

In such normal metals, each quasiparticle, or discrete unit, of charge is the product of incalculable tiny interactions between countless electrons. First put forward 67 years ago, the quasiparticle is a concept physicists use to represent the combined effect of those interactions as a single quantum object for the purposes of quantum mechanical calculations.

Some prior theoretical studies have suggested that the charge in a strange metal might not be carried by such quasiparticles, and shot noise experiments allowed Natelson, study lead author Liyang Chen, a former student in Natelson’s lab, and other Rice and TU Wien co-authors to gather the first direct empirical evidence to test the idea.

“The shot noise measurement is basically a way of seeing how granular the charge is as it goes through something,” Natelson said. “The idea is that if I’m driving a current, it consists of a bunch of discrete charge carriers. Those arrive at an average rate, but sometimes they happen to be closer together in time, and sometimes they’re farther apart.”

Applying the technique in YbRh2Si2 crystals presented significant technical challenges. Shot noise experiments cannot be performed on single macroscopic crystals but, rather, require samples of nanoscopic dimensions. Thus, the growth of extremely thin but nevertheless perfectly crystalline films had to be achieved, something that Paschen, Maxwell Andrews and their collaborators at TU Wien managed after almost a decade of hard work. Next, Chen had to find a way to maintain that level of perfection while fashioning wires from these thin films that were about 5,000 times narrower than a human hair.

Rice co-author Qimiao Si, the lead theorist on the study and the Harry C. and Olga K. Wiess Professor of Physics and Astronomy, said he, Natelson and Paschen first discussed the idea for the experiments while Paschen was a visiting scholar at Rice in 2016. Si said the results are consistent with a theory of quantum criticality he published in 2001 that he has continued to explore in a nearly two-decade collaboration with Paschen.

“The low shot noise brought about fresh new insights into how the charge-current carriers entwine with the other agents of the quantum criticality that underlies the strange metallicity,” said Si, whose group performed calculations that ruled out the quasiparticle picture. “In this theory of quantum criticality, the electrons are pushed to the verge of localization, and the quasiparticles are lost everywhere on the Fermi surface.”

Natelson said the larger question is whether similar behavior might arise in any or all of the dozens of other compounds that exhibit strange metal behavior.

“Sometimes you kind of feel like nature is telling you something,” Natelson said. “This ‘strange metallicity’ shows up in many different physical systems, despite the fact that the microscopic, underlying physics is very different. In copper-oxide superconductors, for example, the microscopic physics is very, very different than in the heavy-fermion system we’re looking at. They all seem to have this linear-in-temperature resistivity that’s characteristic of strange metals, and you have to wonder is there something generic going on that is independent of whatever the microscopic building blocks are inside them.”

The research was supported by the Department of Energy’s Basic Energy Sciences program (DE-FG02-06ER46337), the National Science Foundation (1704264, 2220603), the European Research Council (101055088), the Austrian Science Fund (FWF I4047, FWF SFB F 86), the Austrian Research Promotion Agency (FFG 2156529, FFG 883941), the European Union’s Horizon 2020 program (824109-EMP), the Air Force Office of Scientific Research (FA8665-22-1-7170), the Welch Foundation (C-1411) and the Vannevar Bush Faculty Fellowship (ONR-VB-N00014-23-1-2870).

-30-

This release was authored by Jade Boyd and can be found online at news.rice.edu.

Follow Rice News and Media Relations via Twitter @RiceUNews.

Peer-reviewed paper:

“Shot noise in a strange metal” | Science | DOI: 10.1126/science.abq6100

Authors: Liyang Chen, Dale T. Lowder, Emine Bakali, Aaron M. Andrews, Werner Schrenk, Monika Waas, Robert Svagera, Gaku Eguchi, Lukas Prochaska, Yiming Wang, Chandan Setty, Shouvik Sur, Qimiao Si, Silke Paschen and Douglas Natelson

https://doi.org/10.1126/science.abq6100

Image downloads:

https://news-network.rice.edu/news/files/2023/11/Doug-and-Liyang-at-defense.jpg
CAPTION: Physicists Liyang Chen (left) and Doug Natelson. (Photo courtesy of D. Natelson/Rice University)

https://news-network.rice.edu/news/files/2023/11/231113_Natelson_Fitlow_018.jpg
CAPTION: Rice University physicist Doug Natelson. (Photo by Jeff Fitlow/Rice University)

https://news-network.rice.edu/news/files/2023/11/1123_SHOTNOISE-spqm8-lg.jpg
CAPTION: Physicists Silke Paschen (left) of Vienna University of Technology and Qimiao Si of Rice University. (Photo by Tommy LaVergne/Rice University)

Related stories:

A hallmark of superconductivity, beyond superconductivity itself – Aug. 21, 2019
https://news2.rice.edu/2019/08/21/a-hallmark-of-superconductivity-beyond-superconductivity-itself/

Study finds billions of quantum entangled electrons in ‘strange metal’ – Jan. 16, 2020
https://news.rice.edu/news/2020/study-finds-billions-quantum-entangled-electrons-strange-metal

Heavy fermions get nuclear boost on way to superconductivity – Jan. 28, 2016
https://news2.rice.edu/2016/01/28/heavy-fermions-get-nuclear-boost-on-way-to-superconductivity/

Electron politics: Physicists probe organization at the quantum level – April 25, 2012
https://news2.rice.edu/2012/04/25/electron-politics-physicists-probe-organization-at-the-quantum-level/

Quantum fractals at the border of magnetism – July 28, 2010
https://news2.rice.edu/2010/07/28/quantum-fractals-at-the-border-of-magnetism/

Quantum effects writ large – Feb. 15, 2007
https://news2.rice.edu/2007/02/15/quantum-effects-writ-large/

 

About Rice:

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of architecture, business, continuing studies, engineering, humanities, music, natural sciences and social sciences and is home to the Baker Institute for Public Policy. With 4,574 undergraduates and 3,982 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction, No. 2 for best-run colleges and No. 12 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance.


 

Study reveals how shipwrecks are providing a refuge for marine life


Peer-Reviewed Publication

UNIVERSITY OF PLYMOUTH

A diver examines a wreck 

IMAGE: 

A DIVER EXAMINES A WRECK OFF THE BERWICKSHIRE COAST AND CAPTURES DATA THAT WERE SUBSEQUENTLY USED TO BETTER UNDERSTAND THE BIODIVERSITY WHICH CAN BE FOUND ON SHIPWRECKS

view more 

CREDIT: MARCUSROSE.GUE




An estimated 50,000 shipwrecks can be found around the UK’s coastline and have been acting as a hidden refuge for fish, corals and other marine species in areas still open to destructive bottom towed fishing, a new study has shown.

Many of these wrecks have been lying on the seabed for well over a century, and have served as a deterrent to fishers who use bottom towed trawling to secure their catches.

As a result, while many areas of the seabed have been damaged significantly in areas of heavy fishing pressure, the seabed in and around shipwrecks remains largely unblemished.

The new research found that the average density of marine life in areas still open to trawling was 240% greater within wreck sites than in sites actively being used for bottom towed fishing.

In parts of the seabed within a 50m radius of the wrecks, the difference was even greater with the density of marine life 340% greater than in the control sites.

Conversely, in sites closed to trawling, the abundance was 149% greater than on wrecks and 85% greater than on the seabed within a 50m radius of the wrecks.

The study, conducted by the University of Plymouth and Blue Marine Foundation, has been published in the journal Marine Ecology, and is the first to demonstrate the increased ecological importance of shipwrecks – and the areas surrounding them – in areas of heavy fishing pressure.

Jenny Hickman, the study’s lead author, completed the research as part of her MSc Marine Conservation programme at the University of Plymouth.

She said: “The industrial use of bottom towed fishing gear has been commonplace since the 1800s, and has significantly altered marine communities and ecosystem services. Outside of legal protection, only areas inaccessible to trawlers are offered any protection, which is why shipwreck sites are rarely subject to trawling pressure. As many have been in situ for more than 100 years, they offer a baseline of ecological potential when trawling pressure is reduced or removed.”

The research was conducted around five shipwrecks off the Berwickshire coast, which are all thought to have sunk in the late 19th and early 20th centuries.

Constructed from a range of different materials, they sit between 17 and 47metres beneath the ocean surface, with some in areas open to bottom towed fishing and others in areas where some types of fishing are restricted. 

The research teams, supported by local boat crews, gathered video footage of the shipwrecks, the surrounding 50m radius, and control locations more than 150m from the wreck site.

Footage of all the sites was then assessed, with the researchers, who had a particular interesting in finding species deemed to be vulnerable to trawling if it is allowed to continue.

Joe Richards, Scotland Project Manager for Blue Marine Foundation and one of the study’s co-authors, said: “It has long been thought that shipwrecks could be playing an important role in providing sanctuary for marine species to utilise. It is brilliant to see this proven in this study. The research provides and insight into what might be possible if bottom towed fishing activity is reduced. This feeds into our wider understanding of shipwrecks potential to contribute to ecosystem recovery and enhancement, given the sheer number found on the seabed.”

The University and the Blue Marine Foundation have worked together for many years examining the benefits of Marine Protected Areas (MPAs).

This has included studies in the Lyme Bay MPA – off the South Coast of England – which have provided foundational evidence for the UK Government’s current approach to MPA management.

Researchers say the latest study demonstrates the importance of factoring wreck sites into future conservation plans, but also the benefits of Marine Protected Areas (MPAs) status.

Dr Emma Sheehan, Associate Professor of Marine Ecology and senior author, added: “In recent years, the UK has made significant strides in terms of measures to protect the marine environment. There is still much to be done to reach the goal of having 30% of the ocean protected by 2030, but if we are to get close to that we need detailed evidence about what makes our ocean so special and any existing initiatives that are working well. This study builds on our existing work in that regard, and highlights an impact of past human activity that is actually having a positive impact on the seabed today. It is unquestionably something that should be factored into future marine management plans.”
 

There are an estimated 50,000 shipwrecks around the UK’s coastline and they serve as a deterrent to fishers who use bottom towed trawling to secure their catches

CREDIT

marcusrose.gue

New research found that the average density of marine life in areas still open to trawling was 240% greater within wreck sites than in sites actively being used for bottom towed fishing

CREDIT

richwalkergue

Separating out signals recorded at the seafloor


Peer-Reviewed Publication

WASHINGTON UNIVERSITY IN ST. LOUIS

SIMS at Washington University in St. Louis 

IMAGE: 

ROGER BRYANT STUDIED OCEAN FLOOR CORE SAMPLES AT THE SECONDARY ION MASS SPECTROMETRY (SIMS) FACILITY AT WASHINGTON UNIVERSITY IN ST. LOUIS DURING HIS PHD STUDIES. BRYANT AND DAVID FIKE HAVE USED THIS DATA TO PROVE A DISCOVERY THAT WILL FUNDAMENTALLY CHANGE HOW SCIENTISTS USE PYRITE SULFUR ISOTOPES TO STUDY OCEANIC CONDITIONS.

view more 

CREDIT: CLIVE JONES, WASHINGTON UNIVERSITY IN ST. LOUIS




Blame it on plate tectonics. The deep ocean is never preserved, but instead is lost to time as the seafloor is subducted. Geologists are mostly left with shallower rocks from closer to the shoreline to inform their studies of Earth history.

“We have only a good record of the deep ocean for the last ~180 million years,” said David Fike, the Glassberg/Greensfelder Distinguished University Professor of Earth, Environmental, and Planetary Sciences in Arts & Sciences at Washington University in St. Louis. “Everything else is just shallow-water deposits. So it’s really important to understand the bias that might be present when we look at shallow-water deposits.”

One of the ways that scientists like Fike use deposits from the seafloor is to reconstruct timelines of past ecological and environmental change. Researchers are keenly interested in how and when oxygen began to build up in the oceans and atmosphere, making Earth more hospitable to life as we know it.

For decades they have relied on pyrite, the iron-sulfide mineral known as “fool’s gold,” as a sensitive recorder of conditions in the marine environment where it is formed. By measuring the bulk isotopic composition of sulfur in pyrite samples — the relative abundance of sulfur atoms with slightly different mass — scientists have tried to better understand ancient microbial activity and interpret global chemical cycles.

But the outlook for pyrite is not so shiny anymore. In a pair of companion papers published Nov. 24 in the journal Science, Fike and his collaborators show that variations in pyrite sulfur isotopes may not represent the global processes that have made them such popular targets of analysis.

Instead, Fike’s research demonstrates that pyrite responds predominantly to local processes that should not be taken as representative of the whole ocean. A new microanalysis approach developed at Washington University helped the researchers to separate out signals in pyrite that reveal the relative influence of microbes and that of local climate.

For the first study, Fike worked with Roger Bryant, who completed his graduate studies at Washington University, to examine the grain-level distribution of pyrite sulfur isotope compositions in a sample of recent glacial-interglacial sediments. They developed and used a cutting-edge analytical technique with the secondary-ion mass spectrometer (SIMS) in Fike’s laboratory.

“We analyzed every individual pyrite crystal that we could find and got isotopic values for each one,” Fike said. By considering the distribution of results from individual grains, rather than the average (or bulk) results, the scientists showed that it is possible to tease apart the role of the physical properties of the depositional environment, like the sedimentation rate and the porosity of the sediments, from the microbial activity in the seabed.

“We found that even when bulk pyrite sulfur isotopes changed a lot between glacials and interglacials, the minima of our single grain pyrite distributions remained broadly constant,” Bryant said. “This told us that microbial activity did not drive the changes in bulk pyrite sulfur isotopes and refuted one of our major hypotheses.”

“Using this framework, we’re able to go in and look at the separate roles of microbes and sediments in driving the signals,” Fike said. “That to me represents a huge step forward in being able to interpret what is recorded in these signals.”

In the second paper, led by Itay Halevy of the Weizmann Institute of Science and co-authored by Fike and Bryant, the scientists developed and explored a computer model of marine sediments, complete with mathematical representations of the microorganisms that degrade organic matter and turn sulfate into sulfide and the processes that trap that sulfide in pyrite.

“We found that variations in the isotopic composition of pyrite are mostly a function of the depositional environment in which the pyrite formed,” Halevy said. The new model shows that a range of parameters of the sedimentary environment affect the balance between sulfate and sulfide consumption and resupply, and that this balance is the major determinant of the sulfur isotope composition of pyrite.

“The rate of sediment deposition on the seafloor, the proportion of organic matter in that sediment, the proportion of reactive iron particles, the density of packing of the sediment as it settles to the seafloor — all of these properties affect the isotopic composition of pyrite in ways that we can now understand,” he said.

Importantly, none of these properties of the sedimentary environment are strongly linked to the global sulfur cycle, to the oxidation state of the global ocean, or essentially any other property that researchers have traditionally used pyrite sulfur isotopes to reconstruct, the scientists said.

“The really exciting aspect of this new work is that it gives us a predictive model for how we think other pyrite records should behave,” Fike said. “For example, if we can interpret other records — and better understand that they are driven by things like local changes in sedimentation, rather than global parameters about ocean oxygen state or microbial activity — then we can try to use this data to refine our understanding of sea level change in the past.”

 

A fifth higher: Tropical cyclones substantially raise the Social Cost of Carbon


Peer-Reviewed Publication

POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH (PIK)




Extreme events like tropical cyclones have immediate impacts, but also long-term implications for societies. A new study published in the journal Nature Communications now finds: Accounting for the long-term impacts of these storms raises the global Social Cost of Carbon by more than 20 percent, compared to the estimates currently used for policy evaluations. This increase is mainly driven by the projected rise of tropical-cyclone damages to the major economies of India, USA, China, Taiwan, and Japan under global warming.

“Intense tropical cyclones have the power to slow down the economic development of a country for more than a decade, our analysis shows. With global warming, the share of the most intense tropical cyclones is expected to increase so it becomes more likely that economies may not be able to recover fully in between storms,” explains Hazem Krichene, author and scientist at the Potsdam Institute for Climate Impact Research (PIK) at the time the research was conducted. That is why long-term implications like reductions in economic growth caused by tropical cyclones may harm economic development even stronger than the direct economic damage of the storms.

The so-called Social Cost of Carbon is a dollar estimate for future costs of societies resulting from the emission of one additional ton of carbon dioxide in the atmosphere. This key metric is widely used in policy evaluations, as it allows comparing the costs of climate change for societies with the costs of climate mitigation measures. “However, long-term effects of extreme events are not taken into account so far, so that current Social Cost of Carbon estimates only reflect a part of the actual costs. This means that the real costs are probably even higher than currently estimated and the benefits of climate mitigation consequently underestimated,” co-author Franziska Piontek from PIK says.

Hotter climate, more intense tropical cyclones, higher costs

For their study the researchers analyzed the economic damages caused by these storms in 41 tropical-cyclone prone countries over the period from 1981 to 2015 and projected them for future global warming scenarios. In contrast to previous studies they thereby accounted for the mostly negative long-term impacts of these storms on economic development. The researchers found that these impacts increase the Social Cost of Carbon by more than 20 percent globally (from 173 US$ to 212 US$ per ton CO2) and by more than 40 percent in the analyzed tropical-cyclone prone countries - compared to the Social Cost of Carbon estimates currently used for policy evaluations.

“When it comes to extreme events, much focus is put on immediate economic damages. However, it is as crucial to better quantify the overall costs of these events to inform societies upon the real costs of climate change and the climate impacts that can be avoided by effective climate action”, concludes study author Christian Otto from PIK.