Fiber optic cables detect and characterize earthquakes

Peer-Reviewed Publication

CALIFORNIA INSTITUTE OF TECHNOLOGY

 

IMAGE: GREEN LINES ILLUSTRATE FIBER OPTIC CABLES THROUGHOUT CALIFORNIA; THE SEGMENT MARKED IN RED IS THE SECTION USED TO DETECT THE ANTELOPE VALLEY M6 EARTHQUAKE IN 2021. AS SHOWN IN THE INSET, THE EARTHQUAKE WAS ACTUALLY MADE UP OF FOUR DISTINCT “STUCK” AREAS—THE PURPLE, BLUE, GREEN, AND RED TARGET SYMBOLS—ON THE FAULT THAT RUPTURED SEQUENTIALLY. USING FIBER OPTIC CABLES AS SEISMOMETERS ENABLES HIGH-RESOLUTION IMAGING OF EARTHQUAKE RUPTURES. view more 

CREDIT: COURTESY OF Z. ZHAN

In California, thousands of miles of fiber optic cables crisscross the state, providing people with internet. But these underground cables can also have a surprising secondary function: they can sense and measure earthquakes. In a new study at Caltech, scientists report using a section of fiber optic cable to measure intricate details of a magnitude 6 earthquake, pinpointing the time and location of four individual asperities, the "stuck" areas of the fault, that led to the rupture.

For several years, Professor of Geophysics Zhongwen Zhan (PhD '14) and his team have aimed to show that repurposing fiber optic cables is a simple way to drastically expand our ability to measure seismic activity by producing a dense network of makeshift seismometers in a method called distributed acoustic sensing. The new study, appearing in the journal Nature, utilized only a 100-kilometer section of cable to precisely understand the complex mechanics behind a particular 2021 earthquake, suggesting that access to more cables would enable improved understanding of earthquake physics and ultimately better earthquake early-warning systems.

"If we can get broader coverage to measure seismic activity, we can revolutionize how we study earthquakes and provide more advance warning," says Zhan. "Though we cannot predict earthquakes, distributed acoustic sensing will lead to a better understanding of the details underlying how the earth ruptures."

There are about 500 seismometers throughout the roughly 56,500 square miles in Southern California, and each one costs up to $50,000. On the other hand, utilizing fiber optic cables throughout the state could be equivalent to blanketing it with millions of seismometers.

To use a fiber optic cable as a seismometer, laser emitters are stationed at one end of the cable, shooting beams of light through the long, thin glass strands that make up the cable's core. The glass has tiny imperfections that reflect back a minuscule portion of the light to the source, where it is recorded. In this manner, each imperfection acts as a trackable waypoint along the fiber optic cable, which is typically buried just below ground level. Seismic waves moving through the ground cause the cable to wiggle slightly, which changes the travel time of light to and from these waypoints. Thus, the imperfections along the cable's length act like thousands of individual seismometers that allow seismologists to observe the motion of seismic waves.

In this new study, the team examined the light signatures traveling through a stretch of fiber optic cable located in the Eastern Sierra Nevada during the 2021 Antelope Valley magnitude 6 earthquake. The section of cable was equivalent to 10,000 seismometers and was able to discover that the M6 was made up of a sequence of four smaller ruptures. These so-called "sub-events," like mini earthquakes, could not be detected by a conventional seismic network.

In collaboration with the laboratory of Nadia Lapusta, the Lawrence A. Hanson, Jr., Professor of Mechanical Engineering and Geophysics, the team was able to create an accurate model of the M6 earthquake based on the measured seismic activity. The model showed the timing of the four sub-events and pinpointed their exact locations on the fault region.

"Using fiber optic cable as a series of seismometers reveals aspects of earthquake physics that have long been hypothesized but difficult to image," says Zhan. "As an analogy, imagine your everyday backyard telescope. You can see Jupiter, but you probably can't see its moons or any details. With a really powerful telescope, you can see the fine details of the planet and moon surfaces. Our technology is like a powerful telescope for earthquakes."

The paper is titled "The break of earthquake asperities imaged by distributed acoustic sensing." Jiaxuan Li, postdoctoral scholar research associate in geophysics, is the study's first author. In addition to Zhan, Li, and Lapusta, additional co-authors are graduate student Taeho Kim and DAS scientist Ettore Biondi. Funding was provided by the National Science Foundation.

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JOURNAL

Nature

DOI

10.1038/s41586-023-06227-w 

ARTICLE TITLE

The break of earthquake asperities imaged by distributed acoustic sensing

ARTICLE PUBLICATION DATE

2-Aug-2023

 

Clearcut logging leads to more frequent flooding, including extreme floods

Study also shows that larger, intact watersheds reduce flood risk more effectively

Peer-Reviewed Publication

UNIVERSITY OF BRITISH COLUMBIA

 

IMAGE: DR. YOUNES ALILA view more 

CREDIT: UNIVERSITY OF BRITISH COLUMBIA

Loss of forest cover is associated with more frequent extreme flooding, as well as more frequent floods of any size, according to new UBC research.

While it's widely thought that loss of forest cover is strongly linked to increased flooding, most studies have suggested that the impact is limited to smaller floods. But the study, focused on two snow-dominated regions in British Columbia, the Deadman River and Joe Ross Creek watersheds, argues otherwise.

"When only 21 per cent of trees in the watershed were harvested, using clearcut logging, the average flood size increased by 38 per cent in the Deadman River and a staggering 84 per cent in Joe Ross Creek," says first author Robbie Johnson, who conducted the research as part of his master's in applied science in forestry at UBC. "As well, floods that used to happen only once every 10, 20, 30, 40 and 50 years are all becoming much more common."

Senior author and UBC forestry professor Dr. Younes Alila explains that clearcut logging affects the way snow melts. “Reduced forest cover leads to more snow on the ground and more solar radiation reaching the snowpack. With much less forest cover to catch and shade the snow, more of it melts faster, causing larger floods.”

Impact of local watershed conditions

The researchers also found that the impact of clearcutting on floods is influenced not only by the total size of the logged area, but also by specific local conditions including the size of the watershed, topography, exposure to the sun, storage areas such as lakes, and the location of cut blocks (areas of land with defined boundaries that are authorized for harvest), all of which control the flow of water.

For example, Joe Ross Creek, which has a smaller-sized watershed, higher elevation and mainly south and west exposure, had larger increases in flood size compared to Deadman River, which is about eight times larger, more diverse in exposure to radiation from the sun, and dotted with small lakes.

Despite this, analysis showed that clearcut logging induced similarly large increases in the frequency of the biggest floods. The authors say this is the first study to demonstrate how forests’ ability to mitigate flood risk increases with the size of the watershed.

Improving forest management

The authors used a novel method that isolates the effects of logging from those of the volatile climate background. “This allows for more realistic evaluation of harvesting effects on flood risk in a watershed. It's an approach that can be applied to any other watershed in the Interior and on the coast of B.C.," observed Johnson.

The study provides a vital step forward in our understanding of the intricate relationship between land cover changes and flooding, said Dr. Alila.

"These results emphasize how much the power of forests lies at the watershed scale, especially since replanted forests in the cut blocks are not capable of providing the same hydrologic functions for decades. We hope these insights help to better manage our forests to reduce potential risks to communities and the environment. The way forward is to sustainably reduce clearcutting and, most importantly, consider ecosystem-friendly alternative logging practices, such as thinning and selecting individual trees for harvest.”

Clearcut logging history of Deadman and Joe Ross watersheds

CREDIT

Map credit: UBC Faculty of Forestry/David Leversee

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JOURNAL

Journal of Hydrology

DOI

10.1016/j.jhydrol.2023.129970 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Nonstationary stochastic paired watershed approach: Investigating forest harvesting effects on floods in two large, nested, and snow-dominated watersheds in British Columbia, Canada

 

Genetic variant linked to lower levels of HIV virus in people of African ancestry

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

An international team of researchers has found a genetic variant that may explain why some people of African ancestry have naturally lower viral loads of HIV, reducing their risk of transmitting the virus and slowing progress of their own illness.

Reported today in Nature, this is the first new genetic variant related to HIV infection discovered in nearly 30 years of research. It could, in the future, help direct the development of new treatments approaches for those living with HIV.

HIV remains a major threat to global health. According to UNAIDS, there were 38.4 million people living with HIV globally in 2021. A combination of pre-exposure drugs and medicines that dramatically reduce viral loads has had a major impact on transmission, yet 1.5 million people were newly infected in 2021. And while treatments have improved dramatically since the virus was first identified, 650,000 people still died from AIDS-related illnesses in that year.

Viral load is the amount of a virus in a patient’s system. Higher levels are known to correlate with faster disease progression and increased risk of transmission. But viral load varies widely among infected individuals, influenced by a number of factors including an individual’s genetic makeup.

Most of what we know about the relationship between our DNA and HIV comes from studies among European populations. But given that HIV disproportionately affects people on the African continent – more than 25 million people who are HIV-positive live on the continent – it’s important to better understand the role of genetics in HIV infection in African populations.

To investigate this question, researchers analysed the DNA of almost 4,000 people of African ancestry living with HIV-1, the most common type of the virus. They identified a variant within a region on chromosome 1 containing the gene CHD1L which associated with reduced viral load in carriers of the variant. Between 4% and 13 % of people of African origin are thought to carry this particular variant.

Paul McLaren from the Public Health Agency of Canada’s National Microbiology Laboratory, joint first author, said: “African populations are still drastically underrepresented in human DNA studies, despite experiencing the highest burden of HIV infection. By studying a large sample of people of African ancestry, we’ve been able to identify a new genetic variant that only exists in this population and which is linked to lower HIV viral loads.”

CHD1L is known to play a role in repairing damaged DNA, though it is not clear why the variant should be important in reducing viral load. However, as HIV attacks immune cells, researchers at the University of Cambridge’s Department of Medicine, led by Dr Harriet Groom and Professor Andrew Lever, used stem cells to generate variants of cells that HIV can infect in which CHD1L had either been switched off or its activity turned down.

HIV turned out to replicate better in a type of immune cell known as a macrophage when CHD1L was switched off. In another cell type, the T cell, there was no effect – perhaps surprising since most HIV replication occurs in the latter cell type.

Dr Groom said: “This gene seems to be important to controlling viral load in people of African ancestry. Although we don’t yet know how it’s doing this, every time we discover something new about HIV control, we learn something new about the virus and something new about the cell. The link between HIV replication in macrophages and viral load is particularly interesting and unexpected.”

Co-author Professor Manjinder Sandhu from the Faculty of Medicine at Imperial College London said: “With more than a million new HIV infections a year, it’s clear that we still have a long way to go in the fight against HIV – we are yet to have a vaccine to prevent infection, have yet to find a cure and still see drug resistance emerging in some individuals. The next step is to fully understand exactly how this genetic variant controls HIV replication.”

The research in Cambridge was largely funded by the Medical Research Council. A full list of funders can be found in the research paper.

Reference
McLaren, PJ; Porreca, I; Iaconis, G; Mok, HP, Mukhopadhyay, Sl; Karakoc, E et al. Africa-specific human genetic variation near CHD1L associates with HIV-1 load. Nature; 2 Aug 2023; DOI: 10.1038/s41586-023-06370-4

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JOURNAL

Nature

DOI

10.1038/s41586-023-06370-4 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Africa-specific human genetic variation near CHD1L associates with HIV-1 load

ARTICLE PUBLICATION DATE

2-Aug-2023

Learning how to control HIV from African genomes

Peer-Reviewed Publication

ECOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE

“We searched for human genetic variation that associates with spontaneous control of HIV and identified a novel region in the genome that is only variable in populations of African ancestries,” says Professor Jacques Fellay at EPFL’s School of Life Sciences. “We used a combination of computational and experimental approaches to explore the biological mechanism behind the genetic association and provide evidence that the gene CHD1L acts to limit HIV replication in a subset of white blood cells.”

HIV is still a problem

Despite significant advances in treatment and access to therapy, the human immunodeficiency virus remains a global health challenge with almost 40 million affected individuals, no vaccine and no cure. The virus attacks the person’s immune cells (helper T cells, macrophages, and dendritic cells) damaging their ability to mount an immune response. Without treatment, the infected person grows more susceptible to opportunistic infections and cancer, and can develop acquired immunodeficiency syndrome, the well-known AIDS.

Although annual HIV infections have been declining because of widespread antiretroviral therapies, the trend has slowed substantially since 2005, and there are now alarming increases in the number of newly infected adults in some regions.

HIV and studies on the human genome

The way to therapies involves fundamental research, including studies into the relationship between the human genome and the progression of HIV infection, which can reveal possible therapeutic targets.

These Genome-Wide Association Studies, or GWAS, analyze the entire genome of a large number of individuals to identify genetic variants associated with a clinical outcome, such as the ability to naturally control viral replication.

Measuring HIV replication control: not enough in African populations

The degree of viral infection is measured by the virus’ “setpoint viral load” (spVL), which refers to the relatively stable level of HIV replication in the body after the initial, acute phase of infection in untreated individuals.

A critical determinant of HIV infection progression and transmissibility, spVL is expressed as the number of viral copies per milliliter of plasma. The spVL of HIV varies widely in the infected population, depending on the ability of every individual's immune system to control viral replication without antiretroviral drugs.

Although there have been large studies of spVL control in populations of European descent, much less has been done in populations of African ancestries, which are still drastically underrepresented in human genomic studies. This is both a significant problem considering the disproportionate HIV burden in Africa and a missed opportunity given the high genome diversity among people of African descent, which fosters a high probability of genetic discoveries.

A key gene for resistance to HIV replication in people of African ancestries

To address this disparity, a large international collaboration of scientists and clinicians has now performed large-scale GWAS using data from diverse populations of African ancestries. In total, the scientists analyzed the genomes from 3,879 individuals living with HIV-1. Using computational analysis and fine-mapping techniques, they identified a novel region in the genome that shows a strong association with spVL control.

The study was co-led by Jacques Fellay at EPFL, Paul McLaren at the Public Health Agency of Canada’s National Microbiology Laboratory, and Manjinder Sandhu at Imperial College London. It is now published in Nature.

This region corresponds to a gene known as CHD1L (for “Chromodomain Helicase DNA Binding Protein 1 Like”), which encodes a protein that helps DNA unwind after it has been damaged, allowing it to be repaired. But in this study, the CHD1L gene showed genetic variation specific to populations of African ancestries, and that was linked to the spontaneous control of the most common and virulent type of HIV, called HIV-1.

Having identified CHD1L as a potential modulator of HIV-1 infection, the researchers explored the biological mechanism behind the genetic association and determined that CHD1L plays a role in limiting HIV replication in a subset of white blood cells.

The discovery of CHD1L's role in limiting HIV replication could lead to improved treatment options for infected individuals. “Our findings provide insights into potential therapeutic targets, which are needed to continue the fight against HIV-1,” says Fellay. “In addition, our results underscore the importance of performing genomic studies in diverse ancestral populations to better address their specific medical needs and global health inequities.”

List of other contributors

• Public Health Agency of Canada
• University of Manitoba
• Wellcome Trust Sanger Institute
• University of Cambridge
• King's College London
• Lausanne University Hospital (CHUV) and University of Lausanne
• Swiss Institute of Bioinformatics
• The Jackson Laboratory for Genomic Medicine
• Stanford University
• Northwestern University
• Ragon Institute of MGH, MIT and Harvard
• Frederick National Laboratory for Cancer Research
• San Francisco Department of Public Health
• University of Modena and Reggio Emilia
• Siena University Hospital
• University of Siena
• National Institutes of Health
• Columbia University
• Vanderbilt University School of Medicine
• University of Washington
• London School of Hygiene and Tropical Medicine
• Uganda Virus Research Institute & London School of Hygiene and Tropical Medicine
• Zambia Emory HIV Research Project
• Johns Hopkins University
• University of Amsterdam
• RTI International
• Université Paris Saclay
• Bicêtre Hospital
• Murdoch University and Pathwest
• IrsiCaixa AIDS Research Institute
• University of Vic – Central University of Catalonia
• CIBERINFEC, Instituto de Salud Carlos III
• University of Barcelona
• National Health Laboratory Service, South Africa and University of KwaZulu-Natal
• Copenhagen University Hospital
• San Raffaele Scientific Institute
• Vita-Salute San Raffaele University, School of Medicine Milan
• International AIDS Vaccine Initiative
• University of California, San Francisco
• Inselspital – University Hospital Bern
• Hôpital Saint-Louis
• University of Zurich
• Howard Hughes Medical Institute
• Frederick National Laboratory
• Conservatoire national des arts et métiers
• National University of Singapore
• Queen Mary University of London
• Imperial College London
• Omnigen Biodata

Reference

Paul J. McLaren, Immacolata Porreca, Gennaro Iaconis, Hoi P. Mok, Subhankar Mukhopadhyay, Emre Karakoc, Sara Cristinelli, Cristina Pomilla, István Bartha, Christian W. Thorball, Riley H. Tough, Paolo Angelino, Cher S. Kiar, Tommy Carstensen, Segun Fatumo, Tarryn Porter, Isobel Jarvis, William C Skarnes, Andrew Bassett, Marianne K. DeGorter, Mohana P.S. Moorthy, Jeffrey F. Tuff, Eun-young Kim, Miriam Walter, Lacy M Simons, Arman Bashirova, Susan Buchbinder, Mary Carrington, Andrea Cossarizza, Andrea De Luca, James J. Goedert, David B. Goldstein, David W. Haas, Joshua T. Herbeck, Eric O. Johnson, Pontiano Kaleebu, William Kilembe, Gregory D. Kirk, Neeltje A. Kootstra, Alex H. Kral, Olivier Lambotte, Ma Luo, Simon Mallal, Javier Martinez-Picado, Laurence Meyer, José M. Miro, Pravi Moodley, Ayesha A. Motala, James I. Mullins, Niels Obel, Fraser Pirie, Francis A. Plummer, Guido Poli, Matthew A. Price, Andri Rauch, Ioannis Theodorou, Alexandra Trkola, Bruce D. Walker, Cheryl A. Winkler, Jean-François Zagury, Stephen B. Montgomery, Angela Ciuffi, Judd F. Hultquist, Steven M. Wolinsky, Gordon Dougan, Andrew M.L. Lever, Deepti Gurdasani, Harriet Groom, Manjinder S. Sandhu, Jacques Fellay. Africa-specific human genetic variation near CHD1L associates with HIV-1 load. Nature 02 August 2023. DOI: 10.1038/s41586-023-06370-4

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JOURNAL

Nature

DOI

10.1038/s41586-023-06370-4 

ARTICLE TITLE

Africa-specific human genetic variation near CHD1L associates with HIV-1 load.

ARTICLE PUBLICATION DATE

2-Aug-2023

Can field sobriety tests identify drivers under the influence of cannabis?

 GOOD THING IT'S LEGAL, NOW THEY CAN STUDY IT

UC San Diego scientists evaluate how accurate law-enforcement administered field sobriety tests are at measuring cannabis exposure and impairment

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

 

IMAGE: CANNABIS IS THE ILLICIT DRUG MOST FREQUENTLY FOUND IN THE BLOOD OF DRIVERS INVOLVED IN MOTOR VEHICLE CRASHES, INCLUDING FATAL ONES. view more 

CREDIT: PHOTO BY ELSA OLOFSSON ON UNSPLASH

Road safety is a critical issue in an era of increasing cannabis legalization. Cannabis is known to impair reaction time, decision-making, coordination and perception—skills necessary for safe driving. In the last three years, California has seen a 62% increase in the number of fatal crashes involving drug-related impairment. 

Unlike the association of blood alcohol concentrations with impairment, tetrahydrocannabinol (THC) blood concentrations do not correlate with driving performance. Law enforcement officers instead rely on behavioral tests to determine a driver’s level of impairment. However, these field sobriety tests were primarily validated based on alcohol ingestion, so how useful they are in detecting cannabis impairment remains unclear. 

In a study published August 2, 2023 in JAMA Psychiatry, researchers at the University of California San Diego Center for Medicinal Cannabis Research performed a double-blind, placebo-controlled randomized clinical trial to evaluate how accurate field sobriety tests are in identifying drivers under the influence of THC. The results showed that tests administered by law enforcement officers could differentiate between individuals who had consumed THC versus those who had not at certain time points. Still, the overall accuracy of the tests may be insufficient to denote THC impairment on their own. 

“Driving is a complex task that requires intact attention and motor skills to stay safe,” said first author Thomas Marcotte, PhD, professor of psychiatry at UC San Diego School of Medicine and co-director of the Center for Medicinal Cannabis Research at UC San Diego. “While cannabis can be impairing, the effects vary for each individual. There is thus a public health need to confirm that evaluations of impairment are effective and unbiased, and this study is an important step towards that goal.” 

The study included 184 adult cannabis users between the ages of 21 and 55. During the experiment, 63 participants received a placebo cannabis cigarette while 121 participants received a THC cannabis cigarette. Participants who consumed the THC reported a median highness level of 64 on a scale of 0 to 100, suggesting the content was sufficient to achieve significant intoxication. 

Highly trained law enforcement officers then performed field sobriety tests to examine abilities such as balance, coordination, divided attention and eye movements. These include the Walk and Turn, One Leg Stand, Finger to Nose, Lack of Convergence and Modified Romberg tests. The tests were performed at four different time intervals, roughly one, two, three and four hours after smoking. 

The results showed that officers classified a significantly higher proportion of participants in the THC group as being impaired based on the field sobriety tests compared to the placebo group at three of the four time points measured. For example, one hour after smoking, they labeled 98 participants (81%) from the THC group as being impaired based on their performance, and 31 participants (49%) from the placebo group. But regardless of their actual assignment (THC vs. placebo), officers suspected that 99% of those who failed the tests had received THC. 

Study participants also completed a driving simulation, and their performance was significantly associated with the results of select field sobriety tests, though officers were not privy to this information. 

The researchers concluded that existing field sobriety tests may be sensitive enough to detect those under the influence of cannabis. However, the substantial overlap in poor test performance between the placebo and THC groups, and the high frequency at which officers suspected this was because of THC consumption, suggest that field sobriety tests alone may be insufficient to identify THC-specific driving impairment. 

The authors note that officers in the field would be equipped with more information by interviewing the driver and observing their driving ability, so pairing the field sobriety tests with this additional information could prove more successful in an overall determination of whether a driver is impaired.

“Field sobriety tests are useful additions to overall evaluations of drivers, but are not accurate enough on their own to determine THC impairment,” said Marcotte. “New effective measures for identifying cannabis impairment are needed to ensure the safety of all drivers on the road.” 

The UC San Diego Center for Medicinal Cannabis Research has now partnered with the California Department of Motor Vehicles and the California Highway Patrol on a follow-up study to test various methods of detecting cannabis-impaired driving. The study aims to recruit 300 participants and is set to begin in late summer 2023. 

Co-authors include: David J. Grelotti, Kyle F. Mastropietro, Raymond Theodore Suhandynata, Igor Grant, Anya Umlauf, Emily G. Sones and Robert L. Fitzgerald, all at UC San Diego, as well as Marilyn A. Huestis at Thomas Jefferson University. 

The study was funded by the State of California via Assembly Bill 266, agreement 907.

Full study: doi:10.1001/jamapsychiatry.2023.2345

Cannabis poisonings rise after legalization, new review concludes

Peer-Reviewed Publication

SOCIETY FOR THE STUDY OF ADDICTION

A new meta-analysis (an analysis of past research) published by the scientific journal Addiction has found that cannabis legalisation is associated with increased rates of cannabis poisoning.  The risk of cannabis poisoning was higher among studies that focused on children.

Cannabis poisoning occurs when too much cannabis is consumed at one time.  The effects of cannabis poisoning include lethargy, drowsiness, dizziness, hypertension, palpitations, tachycardia (elevated heart rate), nausea, vomiting, irritability, agitation, coma, and slowing of the central nervous system.  Cannabis use in children (usually inadvertent) is of particular concern as children have the potential for severe toxicity, including coma and neurological and cardiovascular effects.

The analysis pooled the results of 30 studies, including ten abstracts from major clinical toxicology conferences.  The studies reported a general rise in the rate of cannabis poisoning after cannabis legalisation or decriminalisation. However, results among the studies are highly heterogenous, and most of the evidence comes from the USA and Canada, which might not apply in other countries that have legalised or decriminalised cannabis.  Studies that focused on the medical use of cannabis reported a higher risk of poisoning and were less heterogenous than those that included the recreational use of cannabis. Studies that did not report a statistically significant change for overall poisoning often found increases among subgroups, such as children or intensive care admissions.

Senior author Dr. Rose Cairns, from the University of Sydney, says, “Although the results of the studies are varied, almost all of them point to an increase in cannabis poisoning following a change to cannabis laws. The likely explanation is that legislation has increased the use of cannabis, which has also increased poisoning. For example, the modification of cannabis laws could have increased the perceived acceptability of cannabis use (if it’s legal, it must be safe), thereby increasing use.

“Increased availability and use of edibles (gummies and chocolates, for example) appears to be an important driver of the increase in poisonings, particularly among children. Edible cannabis has a higher risk of poisoning because people tend to consume larger quantities, and the effects of cannabis take longer to show up when ingested than they do when smoked.  This is concerning because edibles are especially attractive to children.”

-- Ends –

For editors:

This paper is available Open Access from the Wiley Online Library: https://onlinelibrary.wiley.com/doi/10.1111/add.16280 or by contacting Jean O’Reilly, Editorial Manager, Addiction, jean@addictionjournal.org.

To speak with co-author Professor Nicholas Buckley please contact him via Michelle Blowes, University of Sydney Media and PR Adviser, by email (michelle.blowes@sydney.edu.au) or mobile (+61 (0)478 303 173).

Full citation for article: Allaf S, Lim JS, Buckley NA, and Cairns R. The Impact of Cannabis Legalisation and Decriminalisation on Acute Poisoning: A Systematic Review. Addiction. 2023. DOI: 10.1111/add.16280

Funding: Rose Cairns is supported by an NHMRC Investigator Grant (ID: 1196516), Nicholas Buckley is supported by an NHMRC investigator Grant (ID: 2007726).

Declaration of interests:  None.

Addiction is a monthly international scientific journal publishing peer-reviewed research reports on alcohol, substances, tobacco, and gambling as well as editorials and other debate pieces. Owned by the Society for the Study of Addiction, it has been in continuous publication since 1884.

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JOURNAL

Addiction

DOI

10.1111/add.16280 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The Impact of Cannabis Legalisation and Decriminalisation on Acute Poisoning: A Systematic Review

ARTICLE PUBLICATION DATE

27-Jul-2023

 

Human vs machine

Pitt Professor Takashi D.Y. Kozai says a closer look at nerve insulating cells could be a boon for BCI, and much more

Grant and Award Announcement

UNIVERSITY OF PITTSBURGH

 

IMAGE: IMAGE OF OLIGODENDROCYTE AND MYELIN (GREEN) IN THE BRAIN NEXT TO AN IMPLANTED MICROELECTRODE. OLIGODENDROCYTE SOMAS ARE DENOTED BY WHITE ARROWS, BLOOD VESSELS ARE SHOWN IN RED, AND THE MICROELECTRODE SHANK IS OUTLINED IN BLUE. view more 

CREDIT: KEYING CHEN / UNIVERSITY OF PITTSBURGH

Written by:  Elaine Vitone 

Brain-computer interface (BCI)—an experimental technology that makes it possible to move robotic limbs using only one’s thoughts—holds promise to transform the lives of people with paralysis. But before BCI can make the leap from the lab to patients’ everyday lives, a nagging problem remains: how to coax the body to coexist, for the long haul, with the implants.

“There are two major challenges,” says Takashi (TK) Kozai, associate professor of bioengineering at the University of Pittsburgh Swanson School of Engineering, who leads the BIONIC Lab (Bio-Integrating Optoelectric Neural Interface Cybernetics). For one, over time, scar tissue forms around the electrodes, which complicates the signal’s path to the nearest neuron and dampens the voltage. And for another, there’s a lot of variability in performance. 

“Sometimes these devices work, and sometimes they don't,” he says. 

Overcoming these challenges will be a formidable feat from both the engineering and neurobiology perspectives. Luckily, Kozai lives right at the nexus of the two.

In May, Kozai was awarded $3 million R01 grant over five years from the National Institute of Neurological Disorders and Stroke. The focus of the project is to gain a better understanding of a specific cell type, called oligodendrocytes, which he believes could play a key role in settling this unique human-versus-machine dilemma. 

Oligodendrocytes form the insulative coating known as myelin, which makes neural connections in the brain much faster and more streamlined. Without this insulation, what’s left is a long line of naked axons straining to send impulses along jagged, roundabout paths. That inefficiency, Kozai realized, doesn’t just cause a slowdown, but also means these neurons have to work much harder than their myelinated counterparts, wasting precious energy. “So oligodendrocytes are essentially energy savers,” he says. 

If Kozai’s hunch is correct about oligodendrocytes—an historically understudied cell in his research specialty—this work could have broad implications for a number of debilitating conditions.

Historically, the thinking has been that the trouble with the BCI starts like this: As a result of electrode implantation, blood vessels are damaged, which sends plasma proteins flying off where they shouldn’t be. Their presence on the wrong side of the blood-brain barrier unleashes an assault of immune cells, called microglia. And in that fallout, neurons die. 

But the team began observing that the friendly fire wasn’t the only problem; it was that these neurons, having been choked off from their blood supply, had simply starved to death. So Kozai wondered if they could somehow fortify the neurons against that starvation. “That’s what pointed us toward the oligodendrocytes.”

With this new R01 grant, Kozai is targeting certain progenitor cells that each have potential to give rise to either an oligodendrocyte or enemy number one: scar tissue. In a preliminary study, the team treated these cells with a drug to encourage the former. When administered before implant surgery, they found, the drug helped more neurons survive after the procedure. 

The project will also probe oligodendrocyte health more generally, insights that could potentially expand our understanding of traumatic brain injury and stroke—which both involve a decrease in blood flow in the brain—as well as multiple sclerosis (MS)—an autoimmune onslaught on neurons that’s initially sparked by oligodendrocyte death.

Kozai’s group may be one of the first to have suggested that preserving oligodendrocytes could be a novel treatment against dementia in Alzheimer’s. In that disease, the focus has long been on the plaques that form in the brain. 

“But there’s growing evidence that it’s actually the blood vessels that suffer first—the plaques form on the blood vessels before they form on the neurons,” Kozai explains. Amid the ensuing blood loss, it’s possible the neurons are more vulnerable, unable to maintain a clean environment, “and that, in turn, leads to the plaque forming on the neurons.”

 

Research finds scandals have less impact on politicians than they used to

University of Houston Professor Brandon Rottinghaus culls political scandal data since Watergate, publishes study

Peer-Reviewed Publication

UNIVERSITY OF HOUSTON

Modern American politics has been plagued by scandals from Watergate to Bill Clinton and Monica Lewinsky, to Donald Trump’s Access Hollywood tapes and impeachments. More recently, President Joe Biden’s son Hunter faces tax and gun possession charges, casting a shadow over his father’s re-election bid.

To assess the impact of scandals on a politicians’ ability to survive in office, University of Houston Professor of Political Science Brandon Rottinghaus examined presidential, gubernatorial and Congressional scandals from 1972 to 2021. His article "Do Scandals Matter?” was published in the journal Political Research Quarterly.

“Scandals don’t hit like they used to,” said Rottinghaus. “Politicians involved are able to survive them because you have media much more divided on political terms. You have people who are more partisan and only look at partisan outcomes, and in an odd way, scandals help increase fundraising for some members who are involved in those scandals.”

In his study, Rottinghaus’ definition of scandal involves allegations of illegal, unethical or immoral wrongdoing.

He found negative consequences from scandals vary across time and institutions. Scandals in the Watergate era led to more resignations in Congress, but then in the ‘90s there were fewer resignations of White House officials. During the Trump administration, White House officials did not survive in office at rates greater than past eras. However, politicians generally survived scandal more in this current polarized era, which hints at the changing role of political scandals.

Partisanship, he writes, reduces the negative impact of scandal on some incumbent politicians, as they can largely rely on their base, which is not as critical of the politicians getting caught in scandals.

“This is because they want to see their side win and the other side lose,” he said.

With media, Rottinghaus said because it is more polarized than in past political eras, people can consume the media that fits their political preferences. “That means people are getting only one side of the story. If a politician gets caught in a scandal, that politician can claim the other side is out to get them politically and your base will still like you, despite the scandal.”

And in some ways, small scandals can be beneficial for fundraising. For example, Rottinghaus said, with U.S. Representatives Marjorie Taylor Greene and Lauren Boebert, they can make outlandish statements, send out fundraising appeals and receive many small dollar donors to contribute to their campaigns.

Rottinghaus’s methodology included using three new data sets of scandals involving presidents, members of Congress and governors at the state level over 50 years. He charted the duration of each political, personal and financial scandal faced by an elected official. Then, he investigated what factors hasten the “end” of a scandal, which is defined as when the scandal ends negatively for the elected official. The results clarified how officials survive scandals (or not) and whether the political climate exacerbates the scandal.

"Trump Effect?”

Before this study, Rottinghaus’ data was limited to the middle of former President Barack Obama’s term. He now has updated data through Donald Trump’s presidency and tested whether Trump changed the way scandals affected the American public – something he calls the “Trump Effect.”

“The answer is a tentative yes to that,” Rottinghaus said. “Trump didn’t change the game, but he altered in some ways how scandals affect politicians generally. Although he himself was able to survive these allegations, a lot of his cabinet members did not, yet they did hold on a little longer than they would have in the pre-polarized era.”

In the study, that era begins in the mid-1990s during the Clinton-Lewinsky scandal. “That's the point where you see scandals matter a lot more.”

Overall, Rottinghaus said his study finds scandals do not have as much of an impact as they once did, but their impact also depends on whether the politician is a president, governor, or member of Congress.

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JOURNAL

Political Research Quarterly

DOI

10.1177/10659129231185532 

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Do Scandals Matter?