53 research outputs found

    Effects of Microgravity on mutualistic bacteria

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    Changes in environmental conditions represent a challenge for all terrestrial organisms, including the organisms involved in mutualistic associations (when both organisms obtain a benefit from each other). Changes in environment might include fluctuations in gravity and microgravity which represents a new frontier for space biology research. In this study we utilized Vibrio fischeri, a beneficial symbiotic bacterium of squids and monocentrid fishes. First, Vibrio fischeri was grown under gravity and microgravity conditions using two microgravity analogs: A Rotary Cell Culture System (RCCS) and a 2D clinostat design. After 48 hours of growth, we examined crucial phenotypic changes that might affect bacterial physiology and phenotypic changes involved in host colonization, mutualism and virulence. Phenotypes studied include cell growth, biofilm formation, cell colony morphology, susceptibility to toxic radicals and antibiotic resistance profiles. Our study demonstrates an increase of virulence-related phenotypes on strains grown under microgravity conditions compared to those grown under gravity conditions in both analog systems. This study will provide a window to the adaptative bacterial changes and responses in an effort to shed light on understanding microbiome changes and adaptations in space

    Appearance of Klebsiella Pneumoniae Liver Abscess Syndrome in Argentina: Case Report and Review of Molecular Mechanisms of Pathogenesis

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    Klebsiella pneumoniae liver abscess syndrome (KLAS) is an emerging invasive infection caused by highly virulent community-acquired strains of K. pneumoniae displaying hypermucoviscosity. The salient features of this syndrome include the presence of bacteremia, primary monomicrobial liver abscess, and metastatic complications. A previously healthy Argentinean man presented with fever and found to have liver abscess caused by K. pneumoniae with metastatic seeding of gastric wall. Cultures from blood and liver abscess grew hypermucoviscous K1 K. pneumoniae with sequence type (ST) 23 by multilocus sequence typing (MLST), positive for rmpA (regulator of mucoid phenotype A), wzyKpK1 (capsular polymerase) and aerobactin genes. The hypermucoviscous phenotype of this K. pneumoniae isolate was readily identified by the "string test" (colonies formed a long string when touched with a loop). The patient responded favourably to percutaneous drainage of the abscess and antibiotics. This is the first documented report of KLAS described in Argentina, and may signal the emergence of this syndrome in South America

    Profitability of CAPM Momentum Strategies in the US Stock Market

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    This paper provides a historical review of the performance of the risk-adjusted momentum strategies when buying and selling stocks according to the alpha estimates of the CAPM and Fama–French regressions. Our sample covers over 60 million US daily firm-return observations. High Sharpe ratios are obtained under our risk-adjusted strategies. It is also found that stock market crashes have no apparent impact on our momentum profits

    a cross-sectional international study

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    OBJECTIVE: To know what hospital managers and safety leaders in Ibero-American countries are doing to respond effectively to the occurrence of adverse events (AEs) with serious consequences for patients. DESIGN: Cross-sectional international study. SETTING: Public and private hospitals in Ibero-American countries (Argentina, Brazil, Chile, Colombia, Mexico, Peru, Portugal and Spain). PARTICIPANTS: A convenience sample of hospital managers and safety leaders from eight Ibero-American countries. A minimum of 25 managers/leaders from each country were surveyed. INTERVENTIONS: A selection of 37 actions for the effective management of AEs was explored. These were related to the safety culture, existence of a crisis plan, communication and transparency processes with the patients and their families, attention to second victims and institutional communication. MAIN OUTCOME MEASURE: Degree of implementation of the actions studied. RESULTS: A total of 190 managers/leaders from 126 (66.3%) public hospitals and 64 (33.7%) private hospitals participated. Reporting systems, in-depth analysis of incidents and non-punitive approaches were the most implemented interventions, while patient information and care for second victims after an AE were the least frequent interventions. CONCLUSIONS: The majority of these hospitals have not protocolized how to act after an AE. For this reason, it is urgent to develop and apply a strategic action plan to respond to this imperative safety challenge. This is the first study to identify areas of work and future research questions in Ibero-American countries.publishersversionpublishe

    Ευρετικές προσεγγίσεις του μοναδιάστατου προβλήματος πακετοποίησης

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    Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this species will be considered as synonyms. The older generic epithet takes priority over the younger name. Any widely used younger names proposed for use, must comply with Art. 57.2 and their usage should be approved by the Nomenclature Committee for Fungi (NCF). In this paper, we list all genera currently accepted by us in Dothideomycetes (belonging to 23 orders and 110 families), including pleomorphic and non-pleomorphic genera. In the case of pleomorphic genera, we follow the rulings of the current ICN and propose single generic names for future usage. The taxonomic placements of 1261 genera are listed as an outline. Protected names and suppressed names for 34 pleomorphic genera are listed separately. Notes and justifications are provided for possible proposed names after the list of genera. Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes. A phylogenetic tree based on four gene analyses supported 23 orders and 75 families, while 35 families still lack molecular data

    Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

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    Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

    Medical Education in Infectious Diseases. Using Smartphone Apps for Active Learning

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    Background Active Learning using smartphone technology can be implemented as a tool for teaching medical students (MS) and residents (Rs). The use of technology would increase participation and enhance student learning by engaging them in solving ID clinical case scenarios. Our objective was to describe the methods used and to share the opinions of the users of such active learning methods. Methods The smartphone applications used were Socrative and WhatsApp. We used Socrative during the Universidad Peruana de Ciencias Aplicadas (UPC) ID course for MS in two different ways. In selected lectures (4 of 32), teacher paced questions were asked based on clinical scenarios related to the topic reviewed, and by voluntary homework questionnaires (student paced). At the British American Hospital (BAH) Medicine Department (MS and Rs) Socrative was used similarly: during some noon lectures (teacher paced questions) and during the baseline MS exam and Rs mid-year exam and voluntary homework questions (student paced). WhatsApp is currently used at the BAH with questions send from Monday to Friday. MS /Rs answer individually via WhatsApp to the mentor in charge. The right answer is given the next day. Questions using WhatsApp deal with recent cases seen at the Wards or in the outpatient clinic, and are designed so that the MS/Rs must do quick literature searches in order to provide the right answer. Results Forty-one MS/Rs answered the survey on Socrative use, 25 of 48 (52%) of UPC MS and 16 (89%) MS/Rs from the BAH. Forty (97%) believed using Socrative had influenced their learning and all but 2 believed it promoted participation from the class. 36 (87.8%) would like to have Socrative used in other lectures and 35 (85%) in other courses. Only one person voted against Socrative use in courses or lectures. With regards to WhatsApp use 16 MS/Rs from BAH answered the survey. Six had used before WhatsApp as a teaching tool. All felt the methodology was useful for learning and promoting reading and would recommend this methodology to promote learning on a student paced way. Conclusion Socrative and WhatsApp can be used for teaching ID through MS/Rs smartphones. Most MS/Rs who were surveyed recommended the use of such methods in their education.Revisión por pare

    Medical Education in Infectious Diseases. Using Smartphone Apps for Active Learning

    Get PDF
    Background Active Learning using smartphone technology can be implemented as a tool for teaching medical students (MS) and residents (Rs). The use of technology would increase participation and enhance student learning by engaging them in solving ID clinical case scenarios. Our objective was to describe the methods used and to share the opinions of the users of such active learning methods. Methods The smartphone applications used were Socrative and WhatsApp. We used Socrative during the Universidad Peruana de Ciencias Aplicadas (UPC) ID course for MS in two different ways. In selected lectures (4 of 32), teacher paced questions were asked based on clinical scenarios related to the topic reviewed, and by voluntary homework questionnaires (student paced). At the British American Hospital (BAH) Medicine Department (MS and Rs) Socrative was used similarly: during some noon lectures (teacher paced questions) and during the baseline MS exam and Rs mid-year exam and voluntary homework questions (student paced). WhatsApp is currently used at the BAH with questions send from Monday to Friday. MS /Rs answer individually via WhatsApp to the mentor in charge. The right answer is given the next day. Questions using WhatsApp deal with recent cases seen at the Wards or in the outpatient clinic, and are designed so that the MS/Rs must do quick literature searches in order to provide the right answer. Results Forty-one MS/Rs answered the survey on Socrative use, 25 of 48 (52%) of UPC MS and 16 (89%) MS/Rs from the BAH. Forty (97%) believed using Socrative had influenced their learning and all but 2 believed it promoted participation from the class. 36 (87.8%) would like to have Socrative used in other lectures and 35 (85%) in other courses. Only one person voted against Socrative use in courses or lectures. With regards to WhatsApp use 16 MS/Rs from BAH answered the survey. Six had used before WhatsApp as a teaching tool. All felt the methodology was useful for learning and promoting reading and would recommend this methodology to promote learning on a student paced way. Conclusion Socrative and WhatsApp can be used for teaching ID through MS/Rs smartphones. Most MS/Rs who were surveyed recommended the use of such methods in their education.Revisión por pare
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