157 research outputs found
A new data-based modelling method for identifying parsimonious nonlinear rainfall/flow models
International audienceThe identification of rainfall/runoff relationship is a challenging issue, mainly because of the complexity to find a suitable model for a whole given catchment. Conceptual hydrological models fail to describe correctly the dynamic changes of the system for different rainfall events (e.g. intensity or duration). However, the need for such relationship grows with the water pollution increase in agricultural regions. Lately, a well-known type of model in the control field appears to be a suitable candidate for water processes identification: the Linear Parameter Varying (LPV) models. This paper depicts a novel refined instrumental variable based method for the identification of Input/Output LPV models and this algorithm is applied to identify a parsimonious nonlinear rainfall/flow model of a 42 ha vineyard catchment located in Alsace, France
Identification de modèles LPV : application à la modélisation pluie/débit d'un bassin versant viticole
International audienceL'identification de la relation pluie/débit dans un bassin versant pour la prédiction de débit est un problème stimulant de par la difficulté à caractériser un modèle les décrivant dans leur ensemble. Les modèles conceptuels, basés sur les lois et modèles hydrauliques simples sont sou- vent limités dans la précision de la prédiction qu'ils offrent. L'objectif de cet article est d'une part de montrer l'intérêt des modèles non linéaires de type Linéaires à Paramètres Variants (LPV) par rapport aux modèles linéaires, ainsi que la différence de qualité dans les résultats obtenus selon la méthode employée pour l'identification d'un modèle donné. D'autre part, cet article propose et analyse plusieurs variables de séquencement dont dépendent les paramètres variants des modèles LPV pour représenter les bassins versants ruraux
Structural risk minimization for switched system identification
International audienceThis paper deals with the identification of hybrid dynamical systems that switch arbitrarily between modes. In particular, we focus on the critical issue of estimating the number of modes. A novel method inspired by model selection techniques in statistical learning is proposed. Specifically, the method implements the structural risk minimization principle, which relies on the minimization of an upper bound on the expected prediction error of the model. This so-called generalization error bound is first derived for static switched systems using Rademacher complexities. Then, it is extended to handle non independent observations from a single trajectory of a dynamical system. Finally, it is further tailored to the needs of model selection via a uniformization step. An illustrative example of the behavior of the method and its ability to recover the true number of modes is presented
Results of D-IMPACT
Summary Aims: Diagnosis IMprovement in PrimAry Care Trial (D-IMPACT) was a prospective, multicentre epidemiological study in three European countries to identify the optimal subset of simple tests applied in primary care to diagnose benign prostatic hyperplasia (BPH) in men who spontaneously present with lower urinary tract symptoms (LUTS). Methods: Consecutive male patients aged ≥ 50 years who spontaneously attended their regular general practitioner (GP) office with LUTS were eligible for inclusion if they had not previously undergone BPH diagnostic tests or received treatment for BPH. Patients were assessed on three occasions, twice by their regular GP (visits 1 and 2) and once by a urologist (visit 3). The diagnostic accuracy of each variable was determined using the urologists' final BPH diagnosis (at visit 3) as gold-standard. Independent variables analysed were as follows: age; BPH diagnosis performed by GP in visit 1 (yes/no); probability of BPH diagnosis assessed by GP in visit 1; urinalysis (normal/abnormal); prostate-specific antigen (PSA); International Prostate Symptom Score (IPSS); diagnosis of BPH performed by GP in visit 2 (yes/no); and probability of BPH diagnosis assessed by GP in visit 2. Statistically significant variables (p 1.5 ng/ml and prostate volume ≥ 30 cm3). Among the independent variables analysed, only age, IPSS and PSA showed a statistically significant relationship with BPH diagnosis. In a logistic regression model including age, IPSS, PSA and probability of BPH (based on physical examination and symptoms), positive predictive value (PPV) was 77.1%. Exclusion of BPH probability resulted in a PPV of 75.7%. Conclusions: A diagnostic algorithm including only objective variables (age, IPSS and PSA), easily implemented in any GP office, allows GPs to accurately diagnose BPH in approximately three-quarters of patients spontaneously reporting LUTS
Formação de professores em educação do campo: pedagogia do movimento no paradigma emancipatório
Neste relato busca-se apresentar a experiência vivenciada em uma turma de Licenciatura em Educação do Campo - Ciências da Natureza, em itinerância e alternância. Para auxiliar na construção da identidade docente e a constituição da formação do professor educador do campo, propôs-se a utilização de metodologias alternativas que contemplassem a pedagogia do movimento no paradigma emancipatório, tais como: aprendizagem por projeto, trama conceitual, docência compartilhada e autoavaliação qualitativa emancipatória. Os encaminhamentos se deram em consonância com os princípios da educação do campo, que almejam a construção de uma educação emancipatória por meio do reconhecimento crítico da realidade e da apropriação de conhecimentos necessários para ações pautadas na transformação social
EDUCAÇÃO DO CAMPO: VIVÊNCIAS TRANSFORMADORAS NA REALIDADE LOCAL
EDUCAÇÃO DO CAMPO: VIVÊNCIAS TRANSFORMADORAS NA REALIDADE LOCA
Suppression of HBV by Tenofovir in HBV/HIV Coinfected Patients: A Systematic Review and Meta-Analysis
Background:Hepatitis B coinfection is common in HIV-positive individuals and as antiretroviral therapy has made death due to AIDS less common, hepatitis has become increasingly important. Several drugs are available to treat hepatitis B. The most potent and the one with the lowest risk of resistance appears to be tenofovir (TDF). However there are several questions that remain unanswered regarding the use of TDF, including the proportion of patients that achieves suppression of HBV viral load and over what time, whether suppression is durable and whether prior treatment with other HBV-active drugs such as lamivudine, compromises the efficacy of TDF due to possible selection of resistant HBV strains.Methods:A systematic review and meta-analysis following PRISMA guidelines and using multilevel mixed effects logistic regression, stratified by prior and/or concomitant use of lamivudine and/or emtricitabine.Results:Data was available from 23 studies including 550 HBV/HIV coinfected patients treated with TDF. Follow up was for up to seven years but to ensure sufficient power the data analyses were limited to three years. The overall proportion achieving suppression of HBV replication was 57.4%, 79.0% and 85.6% at one, two and three years, respectively. No effect of prior or concomitant 3TC/FTC was shown. Virological rebound on TDF treatment was rare.Interpretation:TDF suppresses HBV to undetectable levels in the majority of HBV/HIV coinfected patients with the proportion fully suppressed continuing to increase during continuous treatment. Prior treatment with 3TC/FTC does not compromise efficacy of TDF treatment. The use of combination treatment with 3TC/FTC offers no significant benefit over TDF alone
Suppression of HBV by Tenofovir in HBV/HIV coinfected patients : a systematic review and meta-analysis
Background: Hepatitis B coinfection is common in HIV-positive individuals and as antiretroviral therapy has made death due to AIDS less common, hepatitis has become increasingly important. Several drugs are available to treat hepatitis B. The most potent and the one with the lowest risk of resistance appears to be tenofovir (TDF). However there are several questions that remain unanswered regarding the use of TDF, including the proportion of patients that achieves suppression of HBV viral load and over what time, whether suppression is durable and whether prior treatment with other HBV-active drugs such as lamivudine, compromises the efficacy of TDF due to possible selection of resistant HBV strains.
Methods: A systematic review and meta-analysis following PRISMA guidelines and using multilevel mixed effects logistic regression, stratified by prior and/or concomitant use of lamivudine and/or emtricitabine.
Results: Data was available from 23 studies including 550 HBV/HIV coinfected patients treated with TDF. Follow up was for up to seven years but to ensure sufficient power the data analyses were limited to three years. The overall proportion achieving suppression of HBV replication was 57.4%, 79.0% and 85.6% at one, two and three years, respectively. No effect of prior or concomitant 3TC/FTC was shown. Virological rebound on TDF treatment was rare.
Interpretation: TDF suppresses HBV to undetectable levels in the majority of HBV/HIV coinfected patients with the proportion fully suppressed continuing to increase during continuous treatment. Prior treatment with 3TC/FTC does not compromise efficacy of TDF treatment. The use of combination treatment with 3TC/FTC offers no significant benefit over TDF alone
Global Oceans
Global Oceans is one chapter from the State of the Climate in 2019 annual report and is avail-able from https://doi.org/10.1175/BAMS-D-20-0105.1. Compiled by NOAA’s National Centers for Environmental Information, State of the Climate in 2019 is based on contr1ibutions from scien-tists from around the world. It provides a detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instru-ments located on land, water, ice, and in space. The full report is available from https://doi.org /10.1175/2020BAMSStateoftheClimate.1
Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients
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