The link between temperature, dehydration and tectonic tremors in Alaska

by Kobe University

Figure 1: Tectonic map of the Alaska subduction zone.The thick blue solid line outlines the 

Yakutat terrane. The white circle indicates the epicentre of the low-frequency tectonic

 tremors, and the light blue dashed line shows the area where the tectonic tremors 

occurred, which is used in Figures 2 to 4. The area inside the pink dashed box is the

 model region used in this study, and the pink dashed line down the center of the box

 divides the model region into northeast and southwest areas, and represents the 

boundary between the subducted Yakutat terrane and the subducted Pacific plate in the

 model. The black lines indicate the isodepth contours of the upper surface of the subducted

 oceanic plate (with a contour interval of 20 km), red arrows show the plate motion velocity

 in the Aleutian Trench, and the red triangles indicate volcanoes. Credit: Kobe University

A Kobe University research group has shed light on how low-frequency tectonic tremors occur; these findings will contribute towards better predictions of future megathrust earthquakes.

In addition to the subducting Pacific plate, the Alaska subduction zone is also characterized by a subducting oceanic plateau called the Yakutat terrane. Low-frequency tectonic tremors, which are a type of slow earthquake, have only been detected in the subducted Yakutat terrane area. However, the mechanism by which these events occur is not well understood.

Researchers at Kobe University performed a 3D numerical thermomechanical simulation of thermal convection in the Alaska subduction zone with the aim of revealing the mechanism behind these low-frequency tremors. Based on the 3D thermal structure obtained from the simulation, and the indications of hydrous minerals contained in the slab, the researchers calculated the water content distribution and compared the results of these calculations in the area where the tremors occur.

The results revealed high levels of dehydration in the marine sediment layers and ocean crust in the earthquake region. The researchers believe that the reason the tremors only occur in the Yakutat terrane is because the marine sediment layers and ocean crust are thicker there, which means that the level of dehydration is higher than in the western adjacent Pacific plate (where tectonic tremors don't occur).

Figure 2: Temperature distribution in the slab.The temperature distribution is only plotted in

 the region where the depth of the slab surface is shallower than the bottom of the model

 (200 km), with a contour interval of 100 °C. The white line indicates the area where 

low-frequency tectonic tremors occur, as shown in Figure 1. (a) The slab surface (0 km). 

(b) 6 km depth from the slab surface. (c) 10 km depth from the slab surface.

 Credit: Kobe University

The Kobe University research group consisted of second-year master's student Iwamoto Kaya (Department of Planetology, Graduate School of Science), Academic Researcher Suenaga Nobuaki and Professor Yoshida Shoichi (both of the Research Center for Urban Safety and Security).

These results were published in Scientific Reports.

Main points

Elucidating the mechanism by which low-frequency tremors occur is important for understanding the plate subduction process. It is believed that this will also help illuminate how shallower megathrust earthquakes occur.

In this study, the research group constructed a 3D thermomechanical model of the Alaska subduction zone and calculated the subducting plate's maximum water content and level of dehydration.

The dehydration levels from the subducting plate's marine sediment layers and ocean crust were highest in the region where low-frequency tremors occur. Therefore, it is thought that the water expelled from the subducted plate contributes towards the occurrence of these tectonic tremors.

Figure 3: The distribution of the slab’s dehydration gradient.The dehydration gradient 

refers to the water content per unit length in the subduction direction of the plate. 

The dehydration gradient distribution is plotted only in the region where the depth of the 

slab surface is shallower than the bottom of the model (200 km) and where the temperature

 is higher than 200 °C (for which phase diagram data exists). The white line indicates the 

area where low- frequency tectonic tremors occur, as shown in Figure 1. (a) The slab 

surface (0 km). (b) 6 km depth from the slab surface. (c) 10 km depth from the slab 

surface. Credit: Kobe University

Research background

An oceanic plateau called the Yakutat terrane is subducting in the Alaska subduction zone. Low-frequency tectonic tremors occur at this subducting plateau. The region where slow earthquakes (such as low-frequency tectonic tremors) occur is deeper and adjacent to the area where megathrust earthquakes occur, which suggests a connection between the two. Revealing the mechanism behind how low-frequency tectonic tremors occur is therefore important for understanding the occurrence of various earthquake events in subduction zones. This research group constructed a 3D thermomechanical model of the Alaska subduction zone so that they could investigate the temperature and level of dehydration in the areas near where low- frequency tremors occur.

Research methodology

The researchers performed a 3D numerical thermomechanical simulation in accordance with the subduction of the Yakutat terrane and Pacific plate in the Alaska subduction zone. It is thought that as the Pacific plate subducts, it brings the hydrous minerals in the slab into the deep high temperature and high pressure regions, and these conditions cause a dehydration reaction where water is expelled from the hydrous minerals.

Based on the 3D thermal structure obtained from the numerical simulation, the researchers determined dehydration levels of the hydrous minerals in the slab. From these results, it was understood that in the region where low- frequency tremors occur, a large amount of water is expelled due to the high temperature and high pressure conditions that cause the dehydration degradation reactions. It is thought that low frequency earthquakes don't occur in the Pacific plate because it has thin layers and therefore experiences little dehydration. On the other hand, the Yakutat terrane's ocean crust and marine sediment layers are comparatively thicker, meaning that it experiences high levels of dehydration. The researchers concluded that this is why low-frequency tectonic tremors only occur in the Yakutat terrane.

Figure 4: The total sum of the dehydration gradient from the marine sediment layers and 

 ocean crust.The black box indicates the modelled area. The vertical sum of the dehydration

 gradient is only plotted for the region where the depth of the slab surface is shallower than

 the bottom of the model (200 km) and where the temperature is higher than 200 °C 

(for which phase diagram data exists). The white line indicates the area where

 low-frequency tectonic tremors occur, as shown in Figure 1. Credit: Kobe University

Further research

In 1964, a megathrust earthquake occurred in Alaska. This is the biggest earthquake that has occurred in the Alaska subduction zone and the second most powerful earthquake recorded in world history. The low-frequency tectonic tremors that were the subject of this research occur close to the epicenter of the 1964 earthquake, at the downdip of the plate interface.

Next, the research group will continue to make thermomechanical models of various subduction zones to search for universal and regional characteristics of the causal mechanisms behind undersea megathrust earthquakes and slow earthquakes. This research will contribute towards improving understanding of how earthquakes occur and our ability to predict future megathrust earthquakes.Weird earthquake reveals hidden mechanism

More information: Kaya Iwamoto et al, Relationship between tectonic tremors and 3-D distributions of thermal structure and dehydration in the Alaska subduction zone, Scientific Reports (2022). DOI: 10.1038/s41598-022-10113-2

Journal information: Scientific Reports 

Provided by Kobe University 

Scaling new heights with new research showing how plants can grow at altitude

Peer-Reviewed Publication

UNIVERSITY OF NOTTINGHAM

 

IMAGE: IMAGE TAKEN DURING RESEARCH OF PLANTS GROWING AT ALTITUDE IN ECUADOR view more 

CREDIT: CRISTIAN MIÑO

A new study has found that plant species are adapted to the altitude where they grow by ‘sensing’ the oxygen levels that surround them.

Altitude is an important part of plant ecology with at least 30% of plant species diversity contained in mountains and climate change is leading to the retreat of alpine species and some crops to higher altitudes. 

Research led by scientists at the University of Nottingham has identified a mechanism through which plants can sense atmospheric oxygen levels (that decrease with altitude) that will help to understand how plants live at high altitude. The work was carried out in collaboration with scientists in Spain and Ecuador and was funded by the Leverhulme Trust. Their findings have been published today in Nature.

Researchers analysed plants growing at low and high-altitude locations. The team, working in Nottingham, Ecuador and Spain was able to identify how oxygen-sensing controls the pathway of chlorophyll synthesis, permitting plants to match the levels of a key toxic chemical to surrounding oxygen levels. 

Climate change is leading to the displacement of wild species and crops (for example coffee) to higher altitudes, this research offers new insights into the underlying genetic mechanisms controlling their ability to survive at different altitudes. This new understanding of the genetic changes plants go through at altitude could lead to approaches to help plant breeders enhance the capacity of crops to grow at higher altitudes.

The research was led by Professor Michael Holdsworth from the University of Nottingham in collaboration with Professor Karina Proaño at ESPE University in Sangolquí, Ecuador and Professor Carlos Alonso Blanco from the Spanish National Centre for Biotechnology CSIC.

Professor Holdsworth commented: “Altitude is a key component of ecology with different altitudes subjecting plants to changing environments, some components of which are fixed by altitude and others that are not. For life at high altitude, it was previously considered that plants need to adapt to many variables, including high UV light and lower temperatures usually present at high altitude but this study is the first time that perception of atmospheric oxygen levels has been shown to be a key determinant of altitude adaptation in plants. “

He continues: “Exploring this novel finding allowed us to show that atmospheric oxygen level is the key determinant of altitude perception. We define the molecular pathway through which oxygen-sensing results in an adapted phenotype and we find that distinct species of flowering plants are adapted to absolute altitude through conserved oxygen-sensing control of chlorophyll synthesis and hypoxia gene expression. Showing that this mechanism works in diverse species provides a new paradigm for plant ecology.”

Since its foundation in 1925, the Leverhulme Trust has provided grants and scholarships for research and education. Today it is one of the largest all-subject providers of funding for research projects, fellowships, studentships, bursaries and prizes in the UK, currently distributing £100 million each year. Awards are made in the responsive mode, with the choice of topic and research design left with applicants. Particular value is placed on research that crosses disciplinary boundaries or that is willing to take risks in its pursuit of new knowledge or understanding. 

 

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JOURNAL

Nature

DOI

10.1038/s41586-022-04740-y 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

An oxygen-sensing mechanism for angiosperm adaptation to altitude

New type of triterpenes discovered

Discovery in fungi overturns current knowledge of highly useful compound, opening up new world for drug discovery

Peer-Reviewed Publication

UNIVERSITY OF TOKYO

 

IMAGE: THIS FIGURE SHOWS THE DIFFERENCE BETWEEN THE PREVIOUS AND ONLY KNOWN WAY OF TRITERPENE BIOSYNTHESIS, COMPARED TO THE NEW PATHWAY WHICH THE RESEARCHERS UNCOVERED. view more 

CREDIT: IKURO ABE, 2022

A remarkable discovery and collaborative effort have revealed a new type of triterpenes, a group of organic compounds which are an important source of many medicines. Until now, all triterpenes were believed to be derived from squalene, itself a type of triterpene. However, for the very first time, researchers witnessed biosynthesis, the formation of complex compounds from simple ones in living organisms, of triterpenes in fungi without the use of squalene. This important discovery opens up a whole new world of possibilities for pharmaceutical science.

Triterpenes are organic compounds which are abundantly found in animals, plants, microorganisms and even us. About 20,000 different triterpenes have been found and they are widely used in cosmetics, food supplements and, most importantly, medicine, thanks to their anti-inflammatory, anti-cancer, anti-diabetic and other valuable properties. Until now, all known triterpenes were thought to be generated from a common precursor or source, squalene.

However, as revealed in Nature, a collaborative effort among the University of Tokyo and KEK in Japan, Wuhan University in China and Bonn University in Germany, has found a new type of triterpenes that doesn’t require squalene

“Nobody could have imagined this happening in nature. This is the discovery of a new biosynthetic machine,” explained Professor Ikuro Abe from the Graduate School of Pharmaceutical Sciences at the University of Tokyo.

Often, multiple enzyme reactions are needed to create complex molecular compounds, such as when our bodies use squalene to create hormones and bile acid. However, in just a single enzyme reaction, a simple molecule called a C5 isoprene unit, or building block, was the starter to construct a very complex triterpene molecular structure.

The discovery happened almost by accident by the team at Wuhan University, who were working on genome mining to find new natural products. They were not necessarily searching for triterpenes, but they found new genes widely distributed in fungi. “They didn’t know the genes’ function,” said Abe. “So they did a characterization of these news genes, and one of them happened to be triterpene synthesis.”

That is when they asked the other teams to get involved. According to Abe, the team at Bonn University are good at chemistry, so they worked on elucidating the detailed enzyme reaction mechanism, and researchers at the University of Tokyo and KEK applied their expertise in structural analysis. He said that once you understand the structure, you can modify it. “Change something here or there and see what happens. We can understand the structure-function relationship. It’s like a puzzle,” he explained.

“Chemistry in nature is more efficient than the chemical synthesis we use in industry. That is why we are interested in the biosynthetic processes done in nature,” Abe said. “Nature’s method is a better, cheaper and cleaner process. We are trying to better understand how processes take place in nature so that we can recreate or redesign it in the lab, to get more and more important and useful compounds.”

This new discovery is only the beginning. “Now that we have solved the protein structure, we are already manipulating the biosynthetic machinery to try to produce more useful molecules, for example, for drug development,” Abe said 

###

Journal article

Hui Tao, Lukas Lauterbach, Guangkai Bian, Rong Chen, Anwei Hou, Takahiro Mori, Shu Cheng, Ben Hu, Li Lu, Xin Mu, Min Li, Naruhiko Adachi, Masato Kawasaki, Toshio Moriya, Toshiya Senda, Xinghuan Wang, Zixin Deng, Ikuro Abe, Jeroen S. Dickschat, Tiangang Liu “Discovery of non-squalene triterpenes” Nature DOI: 10.1038/s41586-022-04773-3 / URL: https://www.nature.com/articles/s41586-022-04773-3

Funding

This study was funded by The Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan (JSPS KAKENHI Grant Number JP16H06443, JP19K15703, JP20H00490, JP20KK0173, JP21K18246), the New Energy and Industrial Technology Development Organization (NEDO, Grant Number JPNP20011), and AMED (Grant Number JP21ak0101164). This work was also supported in part by Platform Project for Supporting Drug Discovery and Life Science Research (Basis of Supporting Innovative Drug Discovery and Life Science Research) from AMED (JP21am0101071 (support number 1553)).

 

Useful Links

Link to paper: https://www.nature.com/articles/s41586-022-04773-3

Link to Lab: https://tennen.f.u-tokyo.ac.jp/index-e.html  

About the University of Tokyo

The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

 

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JOURNAL

Nature

DOI

10.1038/s41586-022-04773-3 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Discovery of non-squalene triterpenes

Racial, ethnic disparities in buprenorphine, naltrexone prescriptions during COVID-19

JAMA Network Open

Peer-Reviewed Publication

JAMA NETWORK

About The Study: The findings of this analysis suggest that the COVID-19 pandemic may have been associated with worsened disparities in filled buprenorphine and naltrexone prescriptions for opioid use disorder among members of racial and ethnic minority groups compared with white patients.

Authors: Sumedha Gupta, Ph.D., of Indiana University-Purdue University Indianapolis, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ 

(doi:10.1001/jamanetworkopen.2022.14765)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

#  #  #

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time http://jamanetwork.com/journals/jamanetworkopen/fullarticle/10.1001/jamanetworkopen.2022.14765?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=060122

About JAMA Network Open: JAMA Network Open is the new online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.

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JOURNAL

JAMA Network Open

National deficit of Black, Hispanic physicians, estimates of time to reach equal representation

JAMA Network Open

Peer-Reviewed Publication

JAMA NETWORK

About The Study: Researchers compared the demographics of the U.S. population with the demographics of the physician workforce and estimated rates at which medical school matriculation would have to increase for Black and Hispanic medical students to reach equal representation in the workforce.

Authors: Hector Mora, M.D., of the Hospital of the University of Pennsylvania in Philadelphia, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ 

(doi:10.1001/jamanetworkopen.2022.15485)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

#  #  #

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time http://jamanetwork.com/journals/jamanetworkopen/fullarticle/10.1001/jamanetworkopen.2022.15485?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=060122

About JAMA Network Open: JAMA Network Open is the new online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.

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JOURNAL

JAMA Network Open

Black youth in racist communities fare worse in mental health treatment

A study finds that community-level racism makes it harder for Black youth to benefit from talk therapy

Peer-Reviewed Publication

ELSEVIER

Washington, DC, June 2, 2022 – A study in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), published by Elsevier, reports that Black youth living in communities with high (vs. low) anti-Black racism are less likely to benefit from psychotherapy ("talk therapy;" such as cognitive behavioral therapy).

Racism is a system that labels and ranks racial groups, deeming specific groups as inferior and affording them fewer opportunities and resources. Racism exists across different levels: internally (e.g., low self-esteem due to internalizing racial stereotypes), interpersonally (e.g., being called a racist slur), and structurally (i.e., attitudes and laws/policies that hinder the well-being of people of Color, such as redlining policies). Previous studies find that anti-Black racism across all three levels is related to worse mental health for Black people, though few have examined whether racism affects intervention efficacy (i.e., how beneficial an intervention, such as psychotherapy or medication, is).

This meta-analytic study – led by Dr. Maggi Price, an Assistant Professor at the Boston College School of Social Work – is the first to assess whether structural racism is associated with mental health treatment efficacy. Specifically, the research team used publicly available data on anti-Black racist attitudes to create a measure of state-level structural racism and analyzed randomized controlled trial data from youth psychotherapy studies of mostly Black youth (36 RCTs representing N=2,182 youth).  

Dr. Price and her team found that psychotherapies in states with higher (vs. lower) levels of anti-Black racism were less effective.

While summarizing the study's main finding, Dr. Price said, "The extent to which racism or other prejudicial attitudes are endorsed in a given community – such as a neighborhood or a state – varies across the country. Our study found that the level of racism in one's community affects how well one does in mental health treatment."  

Dr. Price and her colleagues conducted a similar study on structural sexism and found that girls living in places with more (vs. less) sexism also fared worse in treatment. When asked about these studies' implications for mental health treatment providers, Dr. Price said that since "identity and stigma are central to an individual's well-being—and seemingly help to account for how well one responds to mental health treatment—practitioners should address stigma in treatment."

“Providers should also incorporate advocacy into their practice by recognizing and making efforts to reduce sexism and racism in their patients' environments. Some examples might include advocating for  changes in school policies to eliminate racist disciplinary practices or to integrate implicit bias training to help teachers to be more aware of their biases."  

Dr. Price concluded with a call to improve training and education for providers: “Many training programs don't prepare providers to adequately address stigma and identity with patients. We need to enhance training in culturally responsive care, including how to address racism, sexism, and other stigmas in treatment. Doing so is essential and will help us better serve our patients.”

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Notes for editors
The article is "Meta-analysis: Are Psychotherapies Less Effective for Black Youth in Communities With Higher Levels of Anti-Black Racism?” by Maggi A. Price, PhD, John R. Weisz, PhD, Sarah McKetta, MSc, Nathan L. Hollinsaid, BS, Micah R. Lattanner, PhD, Allecia E. Reid, PhD, Mark L. Hatzenbuehler, PhD (https://doi.org/10.1016/j.jaac.2021.07.808). It currently appears on the JAACAP Articles In Press page and will appear in the Journal of the American Academy of Child and Adolescent Psychiatry, volume 61, issue 6 (June 2022), published by Elsevier.

Copies of this paper are available to credentialed journalists upon request; please contact the JAACAP Editorial Office at support@jaacap.org or +1 202 587 9674. Journalists wishing to interview the authors may contact Maggi Price, PhD, e-mail at maggi.price@bc.edu.

About JAACAP
Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP) is the official publication of the American Academy of Child and Adolescent Psychiatry. JAACAP is the leading journal focusing exclusively on today's psychiatric research and treatment of the child and adolescent. Published twelve times per year, each issue is committed to its mission of advancing the science of pediatric mental health and promoting the care of youth and their families.

The Journal's purpose is to advance research, clinical practice, and theory in child and adolescent psychiatry. It is interested in manuscripts from diverse viewpoints, including genetic, epidemiological, neurobiological, cognitive, behavioral, psychodynamic, social, cultural, and economic. Studies of diagnostic reliability and validity, psychotherapeutic and psychopharmacological treatment efficacy, and mental health services effectiveness are encouraged. The Journal also seeks to promote the well-being of children and families by publishing scholarly papers on such subjects as health policy, legislation, advocacy, culture and society, and service provision as they pertain to the mental health of children and families.

About Elsevier
As a global leader in information and analytics, Elsevier helps researchers and healthcare professionals advance science and improve health outcomes for the benefit of society. We do this by facilitating insights and critical decision-making for customers across the global research and health ecosystems.

In everything we publish, we uphold the highest standards of quality and integrity. We bring that same rigor to our information analytics solutions for researchers, health professionals, institutions and funders.

Elsevier employs 8,700 people worldwide. We have supported the work of our research and health partners for more than 140 years. Growing from our roots in publishing, we offer knowledge and valuable analytics that help our users make breakthroughs and drive societal progress. Digital solutions such such as ScienceDirect, Scopus, SciVal, ClinicalKey and Sherpath support strategic research management, R&D performance, clinical decision support, and health education. Researchers and healthcare professionals rely on our over 2,700 digitized journals, including The Lancet and Cell; our over 43,000 eBook titles; and our iconic reference works, such as Gray's Anatomy. With the Elsevier Foundation and our external Inclusion & Diversity Advisory Board, we work in partnership with diverse stakeholders to advance inclusion and diversity in science, research and healthcare in developing countries and around the world.

Elsevier is part of RELX, a global provider of information-based analytics and decision tools for professional and business customers. www.elsevier.com

 

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JOURNAL

Journal of the American Academy of Child & Adolescent Psychiatry

DOI

10.1016/j.jaac.2021.07.808 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Meta-analysis: Are Psychotherapies Less Effective for Black Youth in Communities With Higher Levels of Anti-Black Racism?

Black, Hispanic people more likely to die than white people after some types of stroke

Peer-Reviewed Publication

AMERICAN ACADEMY OF NEUROLOGY

MINNEAPOLIS – Black and Hispanic people are more likely to die in the first month after certain types of stroke than white people, according to a study published in the June 1, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology.

“We’ve known that there are disparities in death from stroke among racial and ethnic groups in the U.S. due to higher stroke rates, higher burden of risk factors for stroke, socioeconomic inequality and structural racism, but we have needed more information breaking these differences down by type of stroke,” said study author Hugo J. Aparicio, MD, MPH, of Boston University School of Medicine in Massachusetts and a member of the American Academy of Neurology. “These results will help us to better understand the nature of this health inequity.”

For the study, researchers reviewed health records of 37,790 people who had strokes and were hospitalized in the Veterans Health Administration over a 10-year period. They then looked at which participants died during the following month and for more than a year after the stroke.  

A total of 89% of the strokes were ischemic, which are strokes caused by a blood clot. Another 9% were intracerebral hemorrhage strokes and 2% were subarachnoid hemorrhage strokes, both of which are caused by bleeding in the brain. Men made up 98% of the participants.

When researchers adjusted for factors that could affect risk of death after stroke, such as smoking, diabetes, and heart disease, Hispanic people who had subarachnoid hemorrhage strokes had a 10.3% higher risk of death during the month after the stroke than white people with the same type of stroke, with Hispanic people having a 30% increased risk and white people having a 20% increased risk. Black people who had intracerebral hemorrhage strokes had a 3% higher risk of death during the month after the stroke than white people with that type of stroke, with Black people having a 30% increased risk and white people having a 27% increased risk.

“Differences in mortality by race or ethnicity varied substantially when considering specific types of stroke, especially the different types of hemorrhagic stroke,” said Aparicio. “If all types of stroke are considered together as one disease, it may mask underlying racial or ethnic disparities, since risk factors, such as age or blood pressure, and underlying social determinants of health, such as access to health care or structural racism, may vary differently between these outcomes. Given these differences in stroke mortality by race and ethnicity, it is clear that more research is also needed in Native American, Alaska Native, Native Hawaiian and Asian American groups.”

Aparicio noted that future studies should look into group differences in vascular risk factors and management of risk factors, stroke severity, and the effects of racism that may contribute to this inequity in surviving after a stroke.

A limitation of the study was that nearly all of the participants were male veterans, so the results may not apply to women and the general population. In addition, the researchers were not able to adjust for the severity of the strokes.

The study was supported by the Department of Veterans Affairs.

Learn more about stroke at BrainandLife.org, home of the American Academy of Neurology’s free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life® on Facebook, Twitter and Instagram.

When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.

The American Academy of Neurology is the world’s largest association of neurologists and neuroscience professionals, with over 38,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.

For more information about the American Academy of Neurology, visit AAN.com or find us on Facebook, Twitter, Instagram, LinkedIn and YouTube.

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JOURNAL

Neurology

Racial and ethnic disparities in stroke outcomes

Black and Hispanic patients experienced poorer survival after certain strokes

Peer-Reviewed Publication

BOSTON UNIVERSITY SCHOOL OF MEDICINE

(Boston)—Stroke is the fifth leading cause of death in the U.S. Despite declines in stroke mortality in the overall population in recent decades, disparities in incidence remain persistent among Black and Hispanic Americans. Now a new study has found that inequality in survival among Black and Hispanic Americans varies by stroke type.

“While racial and ethnic disparities in stroke outcomes exist, differences by stroke type are less understood. Current evidence for racial and ethnic disparities in stroke mortality, particularly by stroke type, is needed to better understand and characterize the scope of this health inequity,” explained corresponding author Hugo J. Aparicio, MD, MPH, assistant professor of neurology at Boston University School of Medicine and an investigator at the Framingham Heart Study.

Health disparities in stroke patients were investigated among patients admitted to VA hospitals in the U.S. between the years 2002-12. Strokes were categorized into three types: acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). Race and ethnicity data were collected, and patients were categorized as either non-Hispanic White, non-Hispanic Black (African American), or White or Black Hispanic (Latino). The researchers then compared the incidence of death at various time periods after the stroke (hospital admission date to 30 days, 31-90 days, 91 days to one year, and greater than one year).

While Black patients were less likely to die within the first 30 days of hospital admission for AIS, compared to White patients, Black patients experienced higher mortality (3.2 percent higher) compared to White patients within the first 30 days following ICH, while Hispanics had similar mortality compared to Whites for ICH. For SAH, Hispanics had a higher 30-day mortality (10.3 percent higher) compared to Whites, but no other differences in mortality were seen between the two groups for other time periods.

According to the researchers, some causes of disparities seen in survival could be attributed to decreased access to health care services (e.g., for blood pressure medication prescription), less community outreach for preventive health interventions, or variations in acute care or post-hospital discharge processes of care for minority populations. “Furthermore, the prevalence of uncontrolled high blood pressure in the Black population could contribute to higher rates of stroke. Therefore further investigation categorized by stroke type is warranted to address determinants of health inequity, such as individual health risk factors, care process within the hospital, or factors outside the healthcare system, that could be contributing to stroke mortality,” adds Dr. Aparicio.

The researchers believe future studies should investigate group differences in vascular risk factors and risk factor management, stroke severity, the effects of structural racism, and social determinants of health that may contribute to this inequity in stroke survival.

These findings appear in the journal Neurology®, the medical journal of the American Academy of Neurology.

Funding for this study was provided by Veterans Affairs Merit Award I01 CX001025 (Wilson & Cho). Dr. Aparicio is supported by the National Institute on Aging (R01AG054076-02S1), the National Institute of Neurological Disorders and Stroke (L30 NS093634), an American Academy of Neurology Career Development Award, and the Boston University Aram V. Chobanian Assistant Professorship.

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JOURNAL

Neurology

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Racial and Ethnic Differences in Short- and Long-term Mortality by Stroke Type

How can changes to urban neighborhoods and buildings affect microclimates and energy use?

Computational work uses a Chicago neighborhood to understand and quantify climate effects on building energy use from changes in urban design.

DOE/US DEPARTMENT OF ENERGY

Researchers used a neighborhood in Chicago (seen here looking south) to improve understanding and quantification of climate effects on building energy use in cities and microclimate impacts that can occur from changes in urban design. view more

The Science

Heating and cooling for buildings is a large part of global energy demand. In the United States in 2010, buildings accounted for the biggest share (41 percent) of the nation’s energy consumption. This partly explains why despite having only 4.4 percent of the world’s population, the United States consumes 19 percent of the world’s primary energy production. U.S. building energy use amounts to 40 percent of total U.S. carbon dioxide emissions, contributing to global warming and to regional climate change. This research demonstrates a process for testing the design of neighborhoods to understand how it affects local and regional weather patterns and how changing weather patterns can influence building energy demands.

The Impact

The amount of energy that buildings demand depends on very small-scale factors. Buildings’ urban microclimate reflects local weather, the heat from direct and reflected sunlight, and the temperature of other buildings and the ground. This microclimate is also a product of heat exchange between neighboring buildings, heat transfer due to wind, the temperature of city infrastructure, and other urban heat island effects. This can reduce heating demand during colder months, but it may also increase the demand for cooling in the summer. This study’s Chicago Loop test case shows that the design of even a small new development in a neighborhood affects not only its own microclimate, but also the microclimate of the overall neighborhood. These changes affect how all the buildings in a neighborhood use energy. This research helps to evaluate potential changes to future microclimates and building energy demand using global climate projections, combining the effects of population shifts and urbanization. It aids in quantifying and analyzing the relationships among climate, urban morphology, land cover, and energy use. Researchers can use this information for energy-efficient urban development and planning.

Summary

Researchers demonstrated a process for creating and testing example morphologies for new neighborhoods for their impact on local and regional meteorology within a two-way-coupled mesoscale weather model. Their approach enabled them to allocate resulting building-level meteorological profiles to each building in a neighborhood for parallel computation of building-by-building energy use. To accomplish this process, five one-year, four-domain (with different levels of horizontal resolution), nested meteorological simulations using 2015 data were run using the Weather Research and Forecasting (WRF) model on the Titan and Eos supercomputers at Oak Ridge National Laboratory (ORNL) for two locations: one for the ORNL research campus and four for the Chicago Loop area. The researchers generated urban terrain inputs (binary, readable by WRF) using ORNL-produced shapefiles from LiDAR imagery and laser measurement and included these inputs in the WRF simulations. The researchers generated future neighborhood morphologies using the concept of Urban Tissues, in which physical elements and relationships of the existing neighborhood are identified, subsetted, and recombined for the morphology of the new neighborhood. For each of the five meteorological simulations, researchers defined building-specific meteorological profiles at a 90-meter resolution and initialized each building in massively parallel EnergyPlus building energy simulations. As mesoscale models are often coupled with Earth system models to understand regional impacts of large-scale systems under future scenarios, this methodology may be used further to understand global impacts and feedbacks from changes in climate and in urban terrain due to projected shifts in urban population and changes in urbanization.

 

Funding

This research was supported by the DOE Office of Science through the MultiSector Dynamics, Earth, and Environmental System Modeling program.

How buildings contribute to urban heating during heat waves

A bottom-up approach quantifies the contributions of human-caused heating from building energy use during extreme heat events.

DOE/US DEPARTMENT OF ENERGY

Downtown Los Angeles. A new modeling method examined in high resolution how buildings contribute to heat islands, especially during heat waves. view more

Credit: Image courtesy of Pixabay (https://pixabay.com/photos/los-angeles-usa-california-4313327/)

The Science

Previous research has found that heat waves and urban heat island effects reinforce each other’s effects. These heat islands are concentrations of buildings, paved areas, and other surfaces that absorb and retain heat. Emissions of heat from buildings are an important part of this heat island effect. Researchers therefore need to understand the interplay of urban microclimates and these building heat emissions. New research developed a method for modeling urban building energy and associated human-caused heat during city-wide heat waves. The researchers used the method to examine the variation over time and space in emissions of waste heat from buildings in Los Angeles. The study incorporated building type, urban microclimate, and large-scale climate conditions.

The Impact

The method provides a high-resolution representation of how buildings contribute to heat islands during heat waves. It details both the magnitude and distribution of these heating effects. The simulation indicates that heat dispersing from buildings to the urban environment increases by as much as 20 percent during a heat wave. Most of this heat is waste heat from air conditioning. The study’s results will serve as a fundamental step in continued investigations of the feedback between changes in building waste heat and urban microclimates during extreme heat events.

Summary

The world is experiencing more frequent and longer-duration heat waves. These heat waves are a serious threat to human health and the stability of electrical grids. Previous studies have identified positive feedbacks between heat waves and urban heat island effects. Heat discharges from buildings and associated energy use have significant effect on the urban environment, and researchers therefore need to understand the interactive effects of urban microclimate and building heat emissions on the urban energy balance. In this study, scientists developed a coupled-simulation approach to quantify these effects, mapping urban environmental data generated by the mesoscale Weather Research and Forecasting (WRF) model, coupled to the Urban Canopy Model (UCM), to simulate urban building energy flows. The scientists conducted a case study in Los Angeles, California, during a five-day heat wave event in September 2009.

The researchers analyzed the surge in city-scale building heat emission and energy use during the extreme heat event. They first simulated the urban microclimate at high resolution (500 by 500 meters) using WRF-UCM. Next, they generated grid-level building heat emission profiles and aggregated them using prototype building energy models informed by spatially disaggregated urban land use and urban building density data. They analyzed the spatial patterns of anthropogenic heat discharge from the building sector. They also assessed the quantitative relationship with weather conditions and urban land-use dynamics at the grid level. The simulation results indicate that during a heat wave, a rise in building energy use follows, and the associated discharge of anthropogenic waste heat from the buildings to the environment increases by as much as 20 percent on average, varying significantly, both in time and space. Notably, air-conditioning use within buildings intensifies, and resulting waste heat discharges outside of the buildings contribute most (86.5 percent) of the total waste heat transferred to the surrounding urban environment. The study also found that the waste heat discharge in inland, dense urban districts is more sensitive to extreme events than it is in coastal or suburban areas. The generated anthropogenic heat profiles can be used in urban microclimate models to provide a more accurate estimation of urban air temperature rises during heat waves.

 

Funding

This research was supported by the Department of Energy Office of Science as part of research in the MultiSector Dynamics, Earth, and Environmental System Modeling Program.