96 research outputs found

    Genetic resistance to Mycobacterium Tuberculosis infection and disease

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    CITATION: Möller, M. et al. 2018. Genetic resistance to Mycobacterium tuberculosis infection and disease. Frontier in Immunology, 9:2219, 1-13. doi:10.3389/fimmu.2018.02219.The original publication is available from https://www.frontiersin.org/journals/immunology#Natural history studies of tuberculosis (TB) have revealed a spectrum of clinical outcomes after exposure to Mycobacterium tuberculosis, the cause of TB. Not all individuals exposed to the bacteriumwill become diseased and depending on the infection pressure, many will remain infection-free. Intriguingly, complete resistance to infection is observed in some individuals (termed resisters) after intense, continuing M. tuberculosis exposure. After successful infection, the majority of individuals will develop latent TB infection (LTBI). This infection state is currently (and perhaps imperfectly) defined by the presence of a positive tuberculin skin test (TST) and/or interferon gamma release assay (IGRA), but no detectable clinical disease symptoms. The majority of healthy individuals with LTBI are resistant to clinical TB, indicating that infection is remarkably well-contained in these non-progressors. The remaining 5–15% of LTBI positive individuals will progress to active TB. Epidemiological investigations have indicated that the host genetic component contributes to these infection and disease phenotypes, influencing both susceptibility and resistance. Elucidating these genetic correlates is therefore a priority as it may translate to new interventions to prevent, diagnose or treat TB. The most successful approaches in resistance/susceptibility investigation have focused on specific infection and disease phenotypes and the resister phenotype may hold the key to the discovery of actionable genetic variants in TB infection and disease. This review will not only discuss lessons from epidemiological studies, but will also focus on the contribution of epidemiology and functional genetics to human genetic resistance to M. tuberculosis infection and disease.https://www.frontiersin.org/articles/10.3389/fimmu.2018.02219/fullhttps://doi.org/10.3389/fimmu.2018.02219Published review articlePublishers versio

    Browsing Space Weather Data and Models with the Integrated Space Weather Analysis (iSWA) System

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    The Integrated Space Weather Analysis (iSWA) System is a comprehensive web-based platform for space weather information that combines data from solar, heliospheric and geospace observatories with forecasts based on the most advanced space weather models. The iSWA system collects, generates, and presents a wide array of space weather resources in an intuitive, user-configurable, and adaptable format - thus enabling users to respond to current and future space weather impacts as well as enabling post-impact analysis. iSWA currently provides over 200 data and modeling products, and features a variety of tools that allow the user to browse, combine, and examine data and models from various sources. This presentation will consist of a summary of the iSWA products and an overview of the customizable user interfaces, and will feature several tutorial demonstrations highlighting the interactive tools and advanced capabilities

    Variational Monte Carlo for Interacting Electrons in Quantum Dots

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    We use a variational Monte Carlo algorithm to solve the electronic structure of two-dimensional semiconductor quantum dots in external magnetic field. We present accurate many-body wave functions for the system in various magnetic field regimes. We show the importance of symmetry, and demonstrate how it can be used to simplify the variational wave functions. We present in detail the algorithm for efficient wave function optimization. We also present a Monte Carlo -based diagonalization technique to solve the quantum dot problem in the strong magnetic field limit where the system is of a multiconfiguration nature.Comment: 34 pages, proceedings of the 1st International Meeting on Advances in Computational Many-Body Physics, to appear in Journal of Low Temperature Physics (vol. 140, nos. 3/4

    THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE

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    Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managers’ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizations’ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research

    Mutations in CIC and IDH1 cooperatively regulate 2-hydroxyglutarate levels and cell clonogenicity

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    The majority of oligodendrogliomas (ODGs) exhibit combined losses of chromosomes 1p and 19q and mutations of isocitrate dehydrogenase (IDH1-R132H or IDH2-R172K). Approximately 70% of ODGs with 1p19q co-deletions harbor somatic mutations in the Capicua Transcriptional Repressor (CIC) gene on chromosome 19q13.2. Here we show that endogenous long (CIC-L) and short (CIC-S) CIC proteins are predominantly localized to the nucleus or cytoplasm, respectively. Cytoplasmic CIC-S is found in close proximity to the mitochondria. To study wild type and mutant CIC function and motivated by the paucity of 1p19q co-deleted ODG lines, we created HEK293 and HOG stable cell lines ectopically co-expressing CIC and IDH1. Non-mutant lines displayed increased clonogenicity, but cells co-expressing the mutant IDH1-R132H with either CIC-S-R201W or -R1515H showed reduced clonogenicity in an additive manner, demonstrating cooperative effects in our assays. Expression of mutant CIC-R1515H increased cellular 2-Hydroxyglutarate (2HG) levels compared to wild type CIC in IDH1-R132H background. Levels of phosphorylated ATP-citrate Lyase (ACLY) were lower in cell lines expressing mutant CIC-S proteins compared to cells expressing wild type CIC-S, supporting a cytosolic citrate metabolism-related mechanism of reduced clonogenicity in our in vitro model systems. ACLY or phospho-ACLY were similarly reduced in CIC-mutant 1p19q co-deleted oligodendroglioma patient samples

    Genetic Resistance to Mycobacterium tuberculosis Infection and Disease

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    Natural history studies of tuberculosis (TB) have revealed a spectrum of clinical outcomes after exposure to Mycobacterium tuberculosis, the cause of TB. Not all individuals exposed to the bacterium will become diseased and depending on the infection pressure, many will remain infection-free. Intriguingly, complete resistance to infection is observed in some individuals (termed resisters) after intense, continuing M. tuberculosis exposure. After successful infection, the majority of individuals will develop latent TB infection (LTBI). This infection state is currently (and perhaps imperfectly) defined by the presence of a positive tuberculin skin test (TST) and/or interferon gamma release assay (IGRA), but no detectable clinical disease symptoms. The majority of healthy individuals with LTBI are resistant to clinical TB, indicating that infection is remarkably well-contained in these non-progressors. The remaining 5–15% of LTBI positive individuals will progress to active TB. Epidemiological investigations have indicated that the host genetic component contributes to these infection and disease phenotypes, influencing both susceptibility and resistance. Elucidating these genetic correlates is therefore a priority as it may translate to new interventions to prevent, diagnose or treat TB. The most successful approaches in resistance/susceptibility investigation have focused on specific infection and disease phenotypes and the resister phenotype may hold the key to the discovery of actionable genetic variants in TB infection and disease. This review will not only discuss lessons from epidemiological studies, but will also focus on the contribution of epidemiology and functional genetics to human genetic resistance to M. tuberculosis infection and disease

    The Effects of Mental Health First Aid Preparation on Nursing Student Self-Efficacy in their Response to Mental Health Issues

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    Background: Past studies show a high prevalence of nursing students experience depressive symptoms at varying levels of severity. Teaching nursing students early in their studies how to recognize these symptoms in themselves, their peers, or clients, and how to take appropriate action, may promote better outcomes. Studies in Australia and England have found that Mental Health First Aid (MHFA) increases nursing students’ self-confidence when supporting those experiencing mental health crises. Limited Canadian studies regarding MHFA training exist. Purpose: To examine the effect of MHFA training on the self-efficacy of nursing students to deliver mental health first aid in a clinical setting and among peers. Methods: Participants for this study included 22 volunteer first- or second-year students from a three-year accelerated Canadian Baccalaureate nursing program. Each volunteer answered three demographic questions and ranked their confidence level on a 100-point scale to perform five situation-specific MHFA actions for each of two scenarios (peer and clinical). Questionnaires were completed by participants before and after attending a two-day, 14-hour training course on MHFA. Results: Paired t-tests performed on each questionnaire item revealed significant increases in confidence levels to perform situation-specific mental health first aid actions for each scenario from pre- to post-training. Cronbach’s alpha results show acceptable internal reliability for the five-item questionnaires (pre- and post-test for each scenario). Conclusion: Mental Health First Aid training appears to improve the self-efficacy of nursing students to deliver MHFA actions to clients and peers experiencing mental health crises. RĂ©sumĂ© Contexte : Des Ă©tudes antĂ©rieures ont rĂ©vĂ©lĂ© qu’un nombre Ă©levĂ© d’étudiantes et Ă©tudiants en sciences infirmiĂšres Ă©prouvent des symptĂŽmes de dĂ©pression avec diffĂ©rents niveaux de sĂ©vĂ©ritĂ©. Enseigner dĂšs le dĂ©but de leurs Ă©tudes Ă  reconnaĂźtre ces symptĂŽmes chez eux-mĂȘmes, leurs pairs et leurs patients, et comment agir dans ces situations, pourrait favoriser de meilleurs rĂ©sultats. Des Ă©tudes menĂ©es en Australie et en Angleterre auprĂšs d’étudiantes et Ă©tudiants en sciences infirmiĂšres ont montrĂ© qu’une formation en premiers soins en santĂ© mentale (PSSM) renforce leur confiance en eux lorsqu’ils sont confrontĂ©s Ă  une personne aux prises avec un problĂšme de santĂ© mentale. Les Ă©tudes canadiennes sur la formation en PSSM sont limitĂ©es. But : Le but de cette Ă©tude Ă©tait d’évaluer l’impact d’une formation en PSSM sur le sentiment d’auto-efficacitĂ© d’étudiantes et Ă©tudiants en sciences infirmiĂšres dans la prestation de premiers soins en santĂ© mentale en milieu clinique et auprĂšs de leurs pairs. MĂ©thodes : L’échantillon de cette Ă©tude Ă©tait composĂ© de 22 Ă©tudiantes et Ă©tudiants bĂ©nĂ©voles, inscrits en premiĂšre ou deuxiĂšme annĂ©e du baccalaurĂ©at accĂ©lĂ©rĂ© de trois ans en sciences infirmiĂšres au Canada. Tous les participants ont rĂ©pondu Ă  trois questions dĂ©mographiques et ont Ă©valuĂ© leur niveau de confiance sur une Ă©chelle de 100 points, pour effectuer cinq actions de PSSM spĂ©cifiques Ă  une situation pour chacun des deux scĂ©narios (entre pairs et clinique). Les questionnaires ont Ă©tĂ© remplis avant et aprĂšs la participation Ă  une formation de deux jours (14 heures) en PSSM. RĂ©sultats : Des tests t appariĂ©s rĂ©alisĂ©s pour chaque Ă©lĂ©ment du questionnaire ont rĂ©vĂ©lĂ© une augmentation significative des niveaux de confiance de dĂ©montrer des actions spĂ©cifiques de premiers soins en santĂ© mentale pour chacun des scĂ©narios, entre le test prĂ©- et post-formation. Les rĂ©sultats de l’indice alpha de Cronbach rĂ©vĂšlent une fiabilitĂ© interne acceptable pour les questionnaires Ă  cinq Ă©lĂ©ments (prĂ©- et post-test, pour chaque scĂ©nario). Conclusion : Il semble que la formation en PSSM ait un impact positif sur le sentiment d’auto-efficacitĂ© des Ă©tudiantes et Ă©tudiants en sciences infirmiĂšres, les rendant plus aptes Ă  intervenir efficacement auprĂšs des patients et des pairs qui vivent une crise de santĂ© mentale

    Neutrophils: Innate Effectors of TB Resistance?

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    Certain individuals are able to resist Mycobacterium tuberculosis infection despite persistent and intense exposure. These persons do not exhibit adaptive immune priming as measured by tuberculin skin test (TST) and interferon-Îł (IFN-Îł) release assay (IGRA) responses, nor do they develop active tuberculosis (TB). Genetic investigation of individuals who are able to resist M. tuberculosis infection shows there are likely a combination of genetic variants that contribute to the phenotype. The contribution of the innate immune system and the exact cells involved in this phenotype remain incompletely elucidated. Neutrophils are prominent candidates for possible involvement as primers for microbial clearance. Significant variability is observed in neutrophil gene expression and DNA methylation. Furthermore, inter-individual variability is seen between the mycobactericidal capacities of donor neutrophils. Clearance of M. tuberculosis infection is favored by the mycobactericidal activity of neutrophils, apoptosis, effective clearance of cells by macrophages, and resolution of inflammation. In this review we will discuss the different mechanisms neutrophils utilize to clear M. tuberculosis infection. We discuss the duality between neutrophils' ability to clear infection and how increasing numbers of neutrophils contribute to active TB severity and mortality. Further investigation into the potential role of neutrophils in innate immune-mediated M. tuberculosis infection resistance is warranted since it may reveal clinically important activities for prevention as well as vaccine and treatment development

    The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases

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    Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology
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