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Expert Offers Advice on Treating Corns, Calluses

Title: Expert Offers Advice on Treating Corns, Calluses
Category: Health News
Created: 4/24/2016 12:00:00 AM
Last Editorial Review: 4/25/2016 12:00:00 AM




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Teen Birth Rate at Record Low in U.S.

Title: Teen Birth Rate at Record Low in U.S.
Category: Health News
Created: 4/28/2016 12:00:00 AM
Last Editorial Review: 4/29/2016 12:00:00 AM




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U.S. Workplaces Roiled by Post-Election Discord, Poll Finds

Title: U.S. Workplaces Roiled by Post-Election Discord, Poll Finds
Category: Health News
Created: 5/3/2017 12:00:00 AM
Last Editorial Review: 5/4/2017 12:00:00 AM




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Asthma Inhalers Incorrectly Used by Most Kids in Study

Title: Asthma Inhalers Incorrectly Used by Most Kids in Study
Category: Health News
Created: 4/30/2019 12:00:00 AM
Last Editorial Review: 4/30/2019 12:00:00 AM




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Calm Parenting Will Help Children Through Coronavirus Pandemic

Title: Calm Parenting Will Help Children Through Coronavirus Pandemic
Category: Health News
Created: 4/26/2020 12:00:00 AM
Last Editorial Review: 4/26/2020 12:00:00 AM




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As Coronavirus Fears Surge, Keep Cleaning Products Away From Children

Title: As Coronavirus Fears Surge, Keep Cleaning Products Away From Children
Category: Health News
Created: 4/27/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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You Can't Get Coronavirus Through Sex, Study Suggests

Title: You Can't Get Coronavirus Through Sex, Study Suggests
Category: Health News
Created: 4/27/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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There Aren't Enough Coronavirus Test Kits to Safely Reopen America, Experts Warn

Title: There Aren't Enough Coronavirus Test Kits to Safely Reopen America, Experts Warn
Category: Health News
Created: 4/27/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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Coronavirus Antibody Tests Show Inaccuracies, as Some States Prepare to Reopen

Title: Coronavirus Antibody Tests Show Inaccuracies, as Some States Prepare to Reopen
Category: Health News
Created: 4/25/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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States Move Forward With Plans to Reopen as Coronavirus Case Count Passes 930,000

Title: States Move Forward With Plans to Reopen as Coronavirus Case Count Passes 930,000
Category: Health News
Created: 4/26/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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Isolation During Coronavirus Pandemic a Trigger for Depression

Title: Isolation During Coronavirus Pandemic a Trigger for Depression
Category: Health News
Created: 4/27/2020 12:00:00 AM
Last Editorial Review: 4/27/2020 12:00:00 AM




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Bats and Coronaviruses Go Back Centuries

Title: Bats and Coronaviruses Go Back Centuries
Category: Health News
Created: 4/28/2020 12:00:00 AM
Last Editorial Review: 4/28/2020 12:00:00 AM




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National Coronavirus Testing Strategy Announced as States Reopen

Title: National Coronavirus Testing Strategy Announced as States Reopen
Category: Health News
Created: 4/28/2020 12:00:00 AM
Last Editorial Review: 4/28/2020 12:00:00 AM




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Don't Let the Coronavirus Pandemic Rob You of Your Sleep

Title: Don't Let the Coronavirus Pandemic Rob You of Your Sleep
Category: Health News
Created: 4/29/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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Coronavirus Crisis Has Fewer Kids Getting Needed Vaccines

Title: Coronavirus Crisis Has Fewer Kids Getting Needed Vaccines
Category: Health News
Created: 4/29/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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Trump Orders Meat Plants to Stay Open as U.S. Coronavirus Cases Pass 1 Million

Title: Trump Orders Meat Plants to Stay Open as U.S. Coronavirus Cases Pass 1 Million
Category: Health News
Created: 4/29/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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Coronavirus Vaccine Shows Promise

Title: Coronavirus Vaccine Shows Promise
Category: Health News
Created: 4/29/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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AHA News: Coronavirus Intensifies Existing Issues for Older Immigrants

Title: AHA News: Coronavirus Intensifies Existing Issues for Older Immigrants
Category: Health News
Created: 4/28/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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Love in the Time of Coronavirus: Couples Feel the Strain of Lockdown

Title: Love in the Time of Coronavirus: Couples Feel the Strain of Lockdown
Category: Health News
Created: 4/28/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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LA First Major U.S. City to Offer Free Coronavirus Tests

Title: LA First Major U.S. City to Offer Free Coronavirus Tests
Category: Health News
Created: 4/30/2020 12:00:00 AM
Last Editorial Review: 4/30/2020 12:00:00 AM




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During Coronavirus Pandemic, Don't Ignore Symptoms of Heart Attack, Stroke

Title: During Coronavirus Pandemic, Don't Ignore Symptoms of Heart Attack, Stroke
Category: Health News
Created: 4/30/2020 12:00:00 AM
Last Editorial Review: 4/30/2020 12:00:00 AM




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Researchers Report First U.S. Dog With Coronavirus

Title: Researchers Report First U.S. Dog With Coronavirus
Category: Health News
Created: 4/29/2020 12:00:00 AM
Last Editorial Review: 4/30/2020 12:00:00 AM




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Are Face Shields Better Than Face Masks for Coronavirus?

Title: Are Face Shields Better Than Face Masks for Coronavirus?
Category: Health News
Created: 4/30/2020 12:00:00 AM
Last Editorial Review: 4/30/2020 12:00:00 AM




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Company Selling Direct-to-Consumer Coronavirus Antibody Test

Title: Company Selling Direct-to-Consumer Coronavirus Antibody Test
Category: Health News
Created: 4/30/2020 12:00:00 AM
Last Editorial Review: 5/1/2020 12:00:00 AM




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White House Says Coronavirus Vaccine Could Be Ready By January

Title: White House Says Coronavirus Vaccine Could Be Ready By January
Category: Health News
Created: 5/1/2020 12:00:00 AM
Last Editorial Review: 5/1/2020 12:00:00 AM




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New Initiative to Study Coronavirus Genome

Title: New Initiative to Study Coronavirus Genome
Category: Health News
Created: 5/1/2020 12:00:00 AM
Last Editorial Review: 5/1/2020 12:00:00 AM




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Antibodies Found in Nearly All People Infected by New Coronavirus: Study

Title: Antibodies Found in Nearly All People Infected by New Coronavirus: Study
Category: Health News
Created: 5/8/2020 12:00:00 AM
Last Editorial Review: 5/8/2020 12:00:00 AM




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U.S. Jobless Rate at Nearly 15 Percent as Coronavirus Cases Top 1.2 Million

Title: U.S. Jobless Rate at Nearly 15 Percent as Coronavirus Cases Top 1.2 Million
Category: Health News
Created: 5/8/2020 12:00:00 AM
Last Editorial Review: 5/8/2020 12:00:00 AM




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Is Coronavirus Also Sexually Transmitted?

Title: Is Coronavirus Also Sexually Transmitted?
Category: Health News
Created: 5/7/2020 12:00:00 AM
Last Editorial Review: 5/8/2020 12:00:00 AM




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Experts Cast Doubt on Notion That New Strain of Coronavirus Is More Infectious

Title: Experts Cast Doubt on Notion That New Strain of Coronavirus Is More Infectious
Category: Health News
Created: 5/7/2020 12:00:00 AM
Last Editorial Review: 5/8/2020 12:00:00 AM




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Trump Says Obamacare Must Go as U.S. Coronavirus Cases Climb Past 1.2 Million

Title: Trump Says Obamacare Must Go as U.S. Coronavirus Cases Climb Past 1.2 Million
Category: Health News
Created: 5/7/2020 12:00:00 AM
Last Editorial Review: 5/8/2020 12:00:00 AM




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Inhaler Use Up During Coronavirus Pandemic

Between the first seven days of January 2020 and the last seven days of March, mean daily controller inhaler use rose 14.5%.




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Coronavirus Daily Digest: May 6, 2020

A roundup of the latest news about COVID-19




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Coronavirus Daily Digest: May 7, 2020

A roundup of the latest news about COVID-19




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Coronavirus Daily Digest: May 8, 2020

A roundup of the latest news about COVID-19




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Will Warmer Temps Help Contain Coronavirus?

Two new reports suggest that the warm summer months will not significantly slow the novel coronavirus as it spreads around the globe.




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Webinar Recording "An Updated PubMed is on its Way!"

"NCBI Minute: An Updated PubMed is on its Way!" recorded on August 14th, 2019, is now available on the NCBI YouTube channel.




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Webinar Recording "A New PubMed: Highlights for Information Professionals"

In this webinar for librarians and other information professionals you will preview the new, modern PubMed. The new PubMed, currently available at https://pubmed.gov/labs for testing, will be the default PubMed system in early 2020.







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Trump Signs Massive Relief Package Into Law as U.S. Coronavirus Cases Reach 9,000

Title: Trump Signs Massive Relief Package Into Law as U.S. Coronavirus Cases Reach 9,000
Category: Health News
Created: 3/19/2020 12:00:00 AM
Last Editorial Review: 3/19/2020 12:00:00 AM




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Remdesivir (RDV): Experimental Antiviral for Coronavirus (COVID-19)

Title: Remdesivir (RDV): Experimental Antiviral for Coronavirus (COVID-19)
Category: Medications
Created: 3/26/2020 12:00:00 AM
Last Editorial Review: 5/5/2020 12:00:00 AM




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Two previously unrecorded xiphosurid trace fossils, Selenichnites rossendalensis and Crescentichnus tesiltus, from the Middle Jurassic of Yorkshire, UK

The invertebrate trace fossils Selenichnites rossendalensis and Crescentichnus tesiltus are recorded and described from the Middle Jurassic Gristhorpe Member of the Cloughton Formation of the Cleveland Basin. This is the first record of these ichnospecies from the basin and now completes the occurrence of these and other traces assumed to have been made by limulids from all three non-marine formations of the Ravenscar Group.




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Evaluation of an Automated Digital Scoring System of Dental Plaque

Purpose: Measurement of dental plaque is frequently used as an indicator of overall oral health. The purpose of this study was to compare a manual (visual) plaque scoring system (University of Mississippi Oral Hygiene Index, UM-OHI) with an innovative automated digital scoring system.Methods: Mechanically ventilated, intensive care unit (ICU) patients (n=79) were the study population. Informed consent was given by the subject's legally authorized representative. Digital images of dental plaque were taken using an intraoral camera; and the quantity of dental plaque was scored using the UM-OHI and with a digitized automated scoring system. Distributions of dental plaque scores from both methods were plotted. Pearson correlation coefficients and intra-class coefficients were calculated between the two methods.Results: Participant mean age was 57.3 years; respiratory failure was the most prevalent admission diagnosis (55.7%). The mean percentage of dental plaque calculated by the manual method was found to be remarkably higher (67.3% ± 18.7%) than the percentage of dental plaque calculated by the automated scoring method (23.7% ± 15.2%) (p<0.0001). Despite remarkably different distributions of plaque scores, both the automated and manual scoring systems demostrated relatively high correlation (r=0.62) and good reliability (ICC=0.63).Conclusion: The automated digital scoring system resulted in a significantly lower overall percentage of total dental plaque as compared to the UM-OHI manual scoring system. While the automated digital scoring system may be more precise than a manual (visual) scoring system, its use should be weighed against the added effort, cost, and expertise required for the method. Further study is needed to determine whether an automated digital scoring system can be commercialized and is warranted for use outside of research settings.




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Schnyder corneal dystrophy-associated UBIAD1 is defective in MK-4 synthesis and resists autophagy-mediated degradation [Research Articles]

The autosomal dominant disorder Schnyder corneal dystrophy (SCD) is caused by mutations in UbiA prenyltransferase domain-containing protein-1 (UBIAD1), which uses geranylgeranyl pyrophosphate (GGpp) to synthesize the vitamin K2 subtype menaquinone-4 (MK-4). SCD is characterized by opacification of the cornea, owing to aberrant build-up of cholesterol in the tissue. We previously discovered that sterols stimulate association of UBIAD1 with ER-localized HMG-CoA reductase, which catalyzes a rate-limiting step in the synthesis of cholesterol and nonsterol isoprenoids, including GGpp. Binding to UBIAD1 inhibits sterol-accelerated ER-associated degradation (ERAD) of reductase and permits continued synthesis of GGpp in cholesterol-replete cells. GGpp disrupts UBIAD1-reductase binding and thereby allows for maximal ERAD of reductase as well as ER-to-Golgi translocation of UBIAD1. SCD-associated UBIAD1 is refractory to GGpp-mediated dissociation from reductase and remains sequestered in the ER to inhibit ERAD. Here, we report development of a biochemical assay for UBIAD1-mediated synthesis of MK-4 in isolated membranes and intact cells. Using this assay, we compared enzymatic activity of WT UBIAD1 with that of SCD-associated variants. Our studies revealed that SCD-associated UBIAD1 exhibited reduced MK-4 synthetic activity, which may result from its reduced affinity for GGpp. Sequestration in the ER protects SCD-associated UBIAD1 from autophagy and allows intracellular accumulation of the mutant protein, which amplifies the inhibitory effect on reductase ERAD. These findings have important implications not only for the understanding of SCD etiology but also for the efficacy of cholesterol-lowering statin therapy, which becomes limited, in part, because of UBIAD1-mediated inhibition of reductase ERAD.




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Modeling of the Coral Microbiome: the Influence of Temperature and Microbial Network

ABSTRACT

Host-associated microbial communities are shaped by extrinsic and intrinsic factors to the holobiont organism. Environmental factors and microbe-microbe interactions act simultaneously on the microbial community structure, making the microbiome dynamics challenging to predict. The coral microbiome is essential to the health of coral reefs and sensitive to environmental changes. Here, we develop a dynamic model to determine the microbial community structure associated with the surface mucus layer (SML) of corals using temperature as an extrinsic factor and microbial network as an intrinsic factor. The model was validated by comparing the predicted relative abundances of microbial taxa to the relative abundances of microbial taxa from the sample data. The SML microbiome from Pseudodiploria strigosa was collected across reef zones in Bermuda, where inner and outer reefs are exposed to distinct thermal profiles. A shotgun metagenomics approach was used to describe the taxonomic composition and the microbial network of the coral SML microbiome. By simulating the annual temperature fluctuations at each reef zone, the model output is statistically identical to the observed data. The model was further applied to six scenarios that combined different profiles of temperature and microbial network to investigate the influence of each of these two factors on the model accuracy. The SML microbiome was best predicted by model scenarios with the temperature profile that was closest to the local thermal environment, regardless of the microbial network profile. Our model shows that the SML microbiome of P. strigosa in Bermuda is primarily structured by seasonal fluctuations in temperature at a reef scale, while the microbial network is a secondary driver.

IMPORTANCE Coral microbiome dysbiosis (i.e., shifts in the microbial community structure or complete loss of microbial symbionts) caused by environmental changes is a key player in the decline of coral health worldwide. Multiple factors in the water column and the surrounding biological community influence the dynamics of the coral microbiome. However, by including only temperature as an external factor, our model proved to be successful in describing the microbial community associated with the surface mucus layer (SML) of the coral P. strigosa. The dynamic model developed and validated in this study is a potential tool to predict the coral microbiome under different temperature conditions.




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Single-Dose, Intranasal Immunization with Recombinant Parainfluenza Virus 5 Expressing Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Spike Protein Protects Mice from Fatal MERS-CoV Infection

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) can cause severe and fatal acute respiratory disease in humans and remains endemic in the Middle East since first being identified in 2012. There are currently no approved vaccines or therapies available for MERS-CoV. In this study, we evaluated parainfluenza virus 5 (PIV5)-based vaccine expressing the MERS-CoV envelope spike protein (PIV5/MERS-S) in a human DPP4 knockin C57BL/6 congenic mouse model (hDPP4 KI). Following a single-dose intranasal immunization, PIV5-MERS-S induced neutralizing antibody and robust T cell responses in hDPP4 KI mice. A single intranasal administration of 104 PFU PIV5-MERS-S provided complete protection against a lethal challenge with mouse-adapted MERS-CoV (MERSMA6.1.2) and improved virus clearance in the lung. In comparison, single-dose intramuscular immunization with 106 PFU UV-inactivated MERSMA6.1.2 mixed with Imject alum provided protection to only 25% of immunized mice. Intriguingly, an influx of eosinophils was observed only in the lungs of mice immunized with inactivated MERS-CoV, suggestive of a hypersensitivity-type response. Overall, our study indicated that PIV5-MERS-S is a promising effective vaccine candidate against MERS-CoV infection.

IMPORTANCE MERS-CoV causes lethal infection in humans, and there is no vaccine. Our work demonstrates that PIV5 is a promising vector for developing a MERS vaccine. Furthermore, success of PIV5-based MERS vaccine can be employed to develop a vaccine for emerging CoVs such as SARS-CoV-2, which causes COVID-19.




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Complete Structure of the Enterococcal Polysaccharide Antigen (EPA) of Vancomycin-Resistant Enterococcus faecalis V583 Reveals that EPA Decorations Are Teichoic Acids Covalently Linked to a Rhamnopolysaccharide Backbone

ABSTRACT

All enterococci produce a complex polysaccharide called the enterococcal polysaccharide antigen (EPA). This polymer is required for normal cell growth and division and for resistance to cephalosporins and plays a critical role in host-pathogen interaction. The EPA contributes to host colonization and is essential for virulence, conferring resistance to phagocytosis during the infection. Recent studies revealed that the "decorations" of the EPA polymer, encoded by genetic loci that are variable between isolates, underpin the biological activity of this surface polysaccharide. In this work, we investigated the structure of the EPA polymer produced by the high-risk enterococcal clonal complex Enterococcus faecalis V583. We analyzed purified EPA from the wild-type strain and a mutant lacking decorations and elucidated the structure of the EPA backbone and decorations. We showed that the rhamnan backbone of EPA is composed of a hexasaccharide repeat unit of C2- and C3-linked rhamnan chains, partially substituted in the C3 position by α-glucose (α-Glc) and in the C2 position by β-N-acetylglucosamine (β-GlcNAc). The so-called "EPA decorations" consist of phosphopolysaccharide chains corresponding to teichoic acids covalently bound to the rhamnan backbone. The elucidation of the complete EPA structure allowed us to propose a biosynthetic pathway, a first essential step toward the design of antimicrobials targeting the synthesis of this virulence factor.

IMPORTANCE Enterococci are opportunistic pathogens responsible for hospital- and community-acquired infections. All enterococci produce a surface polysaccharide called EPA (enterococcal polysaccharide antigen) required for biofilm formation, antibiotic resistance, and pathogenesis. Despite the critical role of EPA in cell growth and division and as a major virulence factor, no information is available on its structure. Here, we report the complete structure of the EPA polymer produced by the model strain E. faecalis V583. We describe the structure of the EPA backbone, made of a rhamnan hexasaccharide substituted by Glc and GlcNAc residues, and show that teichoic acids are covalently bound to this rhamnan chain, forming the so-called "EPA decorations" essential for host colonization and pathogenesis. This report represents a key step in efforts to identify the structural properties of EPA that are essential for its biological activity and to identify novel targets to develop preventive and therapeutic approaches against enterococci.




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Polygenic risk scores of several subtypes of epilepsies in a founder population

Objective

Polygenic risk scores (PRSs) are used to quantify the cumulative effects of a number of genetic variants, which may individually have a very small effect on susceptibility to a disease; we used PRSs to better understand the genetic contribution to common epilepsy and its subtypes.

Methods

We first replicated previous single associations using 373 unrelated patients. We then calculated PRSs in the same French Canadian patients with epilepsy divided into 7 epilepsy subtypes and population-based controls. We fitted a logistic mixed model to calculate the variance explained by the PRS using pseudo-R2 statistics.

Results

We show that the PRS explains more of the variance in idiopathic generalized epilepsy than in patients with nonacquired focal epilepsy. We also demonstrate that the variance explained is different within each epilepsy subtype.

Conclusions

Globally, we support the notion that PRSs provide a reliable measure to rightfully estimate the contribution of genetic factors to the pathophysiologic mechanism of epilepsies, but further studies are needed on PRSs before they can be used clinically.




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A large Taenidium burrow from the Upper Carboniferous of Corrie, Isle of Arran, and remarks on the association of Taenidium burrows and Diplichnites trails

Large un-walled backfilled burrows of the Taenidium type are known from Paleozoic deltaic marine environments worldwide where they are often associated with Diplichnites trackways. The latter are generally attributed to arthropleurid myriapods and it may be that the burrows were also made by these animals. Here we describe a Taenidium burrow from the Limestone Coal Formation of the Isle of Arran, a formation that also hosts a well-known example of Diplichnites, supporting the association of the two types of trace fossil and extending their known co-occurrence upward into the Upper Carboniferous.




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Rupture geometries in anisotropic amphibolite recorded by pseudotachylytes in the Gairloch Shear Zone, NW Scotland

Recent earthquakes involving complex multi-fault rupture have increased our appreciation of the variety of rupture geometries and fault interactions that occur within the short duration of coseismic slip. Geometrical complexities are intrinsically linked with spatially heterogeneous slip and stress drop distributions, and hence need incorporating into seismic hazard analysis. Studies of exhumed ancient fault zones facilitate investigation of rupture processes in the context of lithology and structure at seismogenic depths. In the Gairloch Shear Zone, NW Scotland, foliated amphibolites host pseudotachylytes that record rupture geometries of ancient low-magnitude (≤MW 3) seismicity. Pseudotachylyte faults are commonly foliation parallel, indicating exploitation of foliation planes as weak interfaces for seismic rupture. Discordance and complexity are introduced by fault segmentation, stepovers, branching and brecciated dilational volumes. Pseudotachylyte geometries indicate that slip nucleation initiated simultaneously across several parallel foliation planes with millimetre and centimetre separations, leading to progressive interaction and ultimately linkage of adjacent segments and branches within a single earthquake. Interacting with this structural control, a lithological influence of abundant low disequilibrium melting-point amphibole facilitated coseismic melting, with relatively high coseismic melt pressure encouraging transient dilational sites. These faults elucidate controls and processes that may upscale to large active fault zones hosting major earthquake activity.

Supplementary material: Supplementary Figures 1 and 2, unannotated versions of field photographs displayed in Figures 4a and 5 respectively, are available at https://doi.org/10.6084/m9.figshare.c.4573256

Thematic collection: This article is part of the SJG Collection on Early-Career Research available at: https://www.lyellcollection.org/cc/SJG-early-career-research




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Dehydroascorbate Reductases and Glutathione Set a Threshold for High-Light-Induced Ascorbate Accumulation

Plants require a high concentration of ascorbate as a redox buffer for survival under stress conditions, such as high light. Dehydroascorbate reductases (DHARs) are enzymes that catalyze the reduction of DHA to ascorbate using reduced glutathione (GSH) as an electron donor, allowing rapid ascorbate recycling. However, a recent study using an Arabidopsis (Arabidopsis thaliana) triple mutant lacking all three DHAR genes (herein called dhar) did not find evidence for their role in ascorbate recycling under oxidative stress. To further study the function of DHARs, we generated dhar Arabidopsis plants as well as a quadruple mutant line combining dhar with an additional vtc2 mutation that causes ascorbate deficiency. Measurements of ascorbate in these mutants under low- or high-light conditions indicated that DHARs have a nonnegligible impact on full ascorbate accumulation under high light, but that they are dispensable when ascorbate concentrations are low to moderate. Because GSH itself can reduce DHA nonenzymatically, we used the pad2 mutant that contains ~30% of the wild-type GSH level. The pad2 mutant accumulated ascorbate at a wild-type level under high light; however, when the pad2 mutation was combined with dhar, there was near-complete inhibition of high-light–dependent ascorbate accumulation. The lack of ascorbate accumulation was consistent with a marked increase in the ascorbate degradation product threonate. These findings indicate that ascorbate recycling capacity is limited in dhar pad2 plants, and that both DHAR activity and GSH content set a threshold for high-light–induced ascorbate accumulation.