31 research outputs found

    Redox Dependent Arsenic Occurrence and Partitioning in an Industrial Coastal Aquifer: Evidence from High Spatial Resolution Characterization of Groundwater and Sediments

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    Superlative levels of arsenic (As) in groundwater and sediment often result from industrial pollution, as is the case for a coastal aquifer in Southern Italy, with a fertilizer plant atop. Understanding conditions under which As is mobilized from the sediments, the source of that As, is necessary for developing eective remediation plans. Here, we examine hydrogeological and geochemical factors that aect groundwater As concentrations in a contaminated coastal aquifer. Groundwater has been subject to pump-and-treat at a massive scale for more than 15 years and is still ongoing. Nevertheless, As concentrations (0.01 to 100 mg/L) that are four orders of magnitude more than Italian drinking water standard of 10 g/L are still present in groundwater collected from about 50 monitoring wells over three years (2011, 2016, and 2018). As was quantiïŹed in three dierent locations by sequential extractions of 29 sediment cores in 2018 (depth 2.5 m to 16.5 m b.g.l.), combined with groundwater As composition, the aqueous and solid partitioning of As were evaluated by partition coecient (Kd) in order to infer the evolution of the contaminant plumes. Most sediment As is found in easily extractable and/or adsorbed on amorphous iron oxides/hydroxides fractions based on sequential extractions. The study shows that As contamination persists, even after many years of active remediation due to the partitioning to sediment solids. This implies that the choice of remediation techniques requires an improved understanding of the biogeochemical As-cycling and high spatial resolution characterization of both aqueous and solid phases for sites of interes

    Star Formation in the Taurus filament L 1495: from Dense Cores to Stars

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    We present a study of dense structures in the L1495 filament in the Taurus Molecular Cloud and examine its star-forming properties. In particular we construct a dust extinction map of the filament using deep near-infrared observations, exposing its small-scale structure in unprecedented detail. The filament shows highly fragmented substructures and a high mass-per-length value of Mline=17M⊙ pc−1M_{line} = 17 M \odot \ pc^{-1}, reflecting star-forming potential in all parts of it. However, a part of the filament, namely B211, is remarkably devoid of young stellar objects. We argue that in this region the initial filament collapse and fragmentation is still taking place and star formation is yet to occur. In the star-forming part of the filament, we identify 39 cores with masses from 0.4to10M⊙0.4 to 10 M \odot and preferred separations in agreement with the local Jeans length. Most of these cores exceed the Bonnor-Ebert critical mass, and are therefore likely to collapse and form stars. The Dense Core Mass Function follows a power law with exponent ⌈=1.2±0.2\lceil = 1.2 \pm 0.2, a form commonly observed in star-forming regions.Astronom

    Navigating the Contested Terrain of Teacher Education Policy and Practice: Authors Respond to SCALE

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    Stanford Center for Assessment, Learning, and Equity (SCALE) provided a commentary on the manuscripts in the first part of this special issue, which highlighted the benefits of edTPA and the necessity for such assessment programs to improve teacher education and strengthen teaching practices. In turn, the authors responded to the SCALE commentary. The authors’ responses raise concerns about equity, fairness, and unintended consequences of teacher performance assessments. These responses highlight the need for continued dialogue on ways to improve teacher education and strengthen the teaching profession

    Navegando no terreno disputado da política e pråtica da formação de professores: Os autores respondem a SCALE

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    Stanford Center for Assessment, Learning, and Equity (SCALE) provided a commentary on the manuscripts in the first part of this special issue, which highlighted the benefits of edTPA and the necessity for such assessment programs to improve teacher education and strengthen teaching practices. In turn, the authors responded to the SCALE commentary. The authors’ responses raise concerns about equity, fairness, and unintended consequences of teacher performance assessments. These responses highlight the need for continued dialogue on ways to improve teacher education and strengthen the teaching profession.Stanford Center for Assessment, Learning and Equity (SCALE) ofreciĂł un comentario sobre los manuscritos en la primera parte de esta edicion especial, que destacĂł los beneficios de edTPA y la necesidad de dichos programas de evaluaciĂłn para mejorar la formaciĂłn docente y para fortalecer las prĂĄcticas docentes. A la vez, los autores respondieron al comentario SCALE. Las respuestas de los autores plantean inquietudes sobre la equidad, la rectitud y las consecuencias involuntarias de las evaluaciones del desempeño docente. Estas respuestas revelan la necesidad de un diĂĄlogo continuo sobre las formas de mejorar la formaciĂłn docente y fortalecer la profesiĂłn docente.Stanford Center for Assessment, Learning and Equity Stanford (SCALE) ofereceu um comentĂĄrio sobre os manuscritos na primeira parte desta edição especial, que destacou os benefĂ­cios do edTPA e a necessidade de tais programas de avaliação para melhorar a formação de professores e fortalecer prĂĄticas de ensino. Ao mesmo tempo, os autores responderam ao comentĂĄrio SCALE. As respostas dos autores levantam preocupaçÔes sobre equidade, retidĂŁo e as conseqĂŒĂȘncias involuntĂĄrias das avaliaçÔes de desempenho dos professores. Essas respostas revelam a necessidade de um diĂĄlogo contĂ­nuo sobre formas de melhorar a formação de professores e fortalecer a profissĂŁo docente

    Compartment-specific immunity in the human gut: Properties and functions of dendritic cells in the colon versus the ileum

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    © 2015 The Authors. Published by BMJ. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: http://dx.doi.org/10.1136/gutjnl-2014-307916Objective Dendritic cells (DC) mediate intestinal immune tolerance. Despite striking differences between the colon and the ileum both in function and bacterial load, few studies distinguish between properties of immune cells in these compartments. Furthermore, information of gut DC in humans is scarce. We aimed to characterise human colonic versus ileal DC. Design Human DC from paired colonic and ileal samples were characterised by flow cytometry, electron microscopy or used to stimulate T cell responses in a mixed leucocyte reaction. Results A lower proportion of colonic DC produced pro-inflammatory cytokines (tumour necrosis factor-a and interleukin (IL)-1ß) compared with their ileal counterparts and exhibited an enhanced ability to generate CD4+FoxP3+IL-10+ (regulatory) T cells. There were enhanced proportions of CD103+Sirpa- DC in the colon, with increased proportions of CD103+Sirpa+ DC in the ileum. A greater proportion of colonic DC subsets analysed expressed the lymph-node-homing marker CCR7, alongside enhanced endocytic capacity, which was most striking in CD103+Sirpa+ DC. Expression of the inhibitory receptor ILT3 was enhanced on colonic DC. Interestingly, endocytic capacity was associated with CD103+ DC, in particular CD103+Sirpa+ DC. However, expression of ILT3 was associated with CD103- DC. Colonic and ileal DC differentially expressed skin-homing marker CCR4 and small-bowel-homing marker CCR9, respectively, and this corresponded to their ability to imprint these homing markers on T cells. Conclusions The regulatory properties of colonic DC may represent an evolutionary adaptation to the greater bacterial load in the colon. The colon and the ileum should be regarded as separate entities, each comprising DC with distinct roles in mucosal immunity and imprinting.This research was funded by St. Mark's Foundation (Harrow, UK), The Biotechnology and Biological Sciences Research Council (BBSRC; BB/J004529/1) and The National Institutes of Health (NIH; US) including The National Institute of Diabetes and Digestive and Kidney Diseases (NIH/NIDDK; T32-DK07632 and P01-DK072084) and The National Institute of Allergy and Infectious Disease (NIH/NIAID; R21-AI094033). We also gratefully acknowledge funding support from The Harvey M. and Lyn P. Meyerhoff Inflammatory Bowel Disease Centre at The Johns Hopkins Hospital, Baltimore, US.Published versio

    Genetic landscape of pediatric acute liver failure of indeterminate origin.

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    BACKGROUND AIMS Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, main causes are viral infections (12-16%) and inherited metabolic diseases (14-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. METHODS With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF (RALF). WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (46%), and in children with RALF (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8) and DGUOK (n=7) were the most frequent findings. When categorizing, most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%) and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplants. CONCLUSION This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Sun exposure and physical activity: the valuable role of UV wearables

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    Skin cancers are one of the most common types of cancer in the United States [1] , and melanoma has steadily increased over the last 20 years. Solar ultraviolet radiation (UVR) is known as the main cause of damaging effects to the skin [1] , [2] , yet also the most preventable risk factor. Outdoor physical activity, an important health behavior, exposes the body to UVR and is thus ostensibly linked to increases the risk of sunburn, melanoma, and non-melanoma skin cancers [3] , [4] . Simultaneously, new UVR sensors can play an essential role in ensuring users gain enough sunlight for Vitamin D synthesis for optimal health. However, accurately monitoring personal UVR exposure is historically complex and costly, and thus minimal research exists at the intersection of personal UVR exposure during physical activity
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