Search results for "Random"
showing 10 items of 3931 documents
Random effects elliptically distributed in unbalanced linear models
2008
In linear mixed effects models, random effects are used for modelling the variance-covariance structure of the response variable. These models are based on the assumption that the random effects are normally distributed, but in literature alternative random effect distributions have been proposed and the consequences of misspecification are investigated. These studies consider only balanced designs. Aim of this paper is to study an unbalanced linear mixed model with random effects elliptically distributed.
Robust estimation of mean electricity consumption curves by sampling for small areas in presence of missing values
2017
In this thesis, we address the problem of robust estimation of mean or total electricity consumption curves by sampling in a finite population for the entire population and for small areas. We are also interested in estimating mean curves by sampling in presence of partially missing trajectories.Indeed, many studies carried out in the French electricity company EDF, for marketing or power grid management purposes, are based on the analysis of mean or total electricity consumption curves at a fine time scale, for different groups of clients sharing some common characteristics.Because of privacy issues and financial costs, it is not possible to measure the electricity consumption curve of eac…
Selectivity in Probabilistic Causality: Where Psychology Runs Into Quantum Physics
2011
Given a set of several inputs into a system (e.g., independent variables characterizing stimuli) and a set of several stochastically non-independent outputs (e.g., random variables describing different aspects of responses), how can one determine, for each of the outputs, which of the inputs it is influenced by? The problem has applications ranging from modeling pairwise comparisons to reconstructing mental processing architectures to conjoint testing. A necessary and sufficient condition for a given pattern of selective influences is provided by the Joint Distribution Criterion, according to which the problem of "what influences what" is equivalent to that of the existence of a joint distr…
Detection of genomic regions underlying milk production traits in Valle del Belice dairy sheep using regional heritability mapping
2021
The aim of this study was to identify genomic regions underlying milk production traits in the Valle del Belice dairy sheep using regional heritability mapping (RHM). Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY), collected over a period of six years (2006-2012) on 481 Valle del Belice ewes, were used for the analysis. Animals were genotyped with the Illumina 50k SNP chip. Variance components, heritabilities, and repeatability within and across lactations were estimated, fitting parity, litter size, season of lambing, and fortnights in milk, as fixed; and additive genetic, permanent environment within and across …
Emergency sclerotherapy versus vasoactive drugs for variceal bleeding in cirrhosis
2003
Abstract Background & aims: Emergency sclerotherapy is used as a first-line therapy for variceal bleeding in cirrhosis, although pharmacologic treatment stops bleeding in most patients. We performed a meta-analysis comparing emergency sclerotherapy with pharmacologic treatment. Methods: MEDLINE (1968–2002), EMBASE (1986–2002), and the Cochrane Library (2002;4) were searched to retrieve randomized controlled trials comparing sclerotherapy with vasopressin (± nitroglycerin), terlipressin, somatostatin, or octreotide for variceal bleeding in cirrhosis. Outcome measures were failure to control bleeding, rebleeding, blood transfusions, adverse events, and mortality. Results: Fifteen trials were …
Eltrombopag before procedures in patients with cirrhosis and thrombocytopenia
2012
Eltrombopag is an oral thrombopoietin-receptor agonist. This study evaluated the efficacy of eltrombopag for increasing platelet counts and reducing the need for platelet transfusions in patients with thrombocytopenia and chronic liver disease who are undergoing an elective invasive procedure.We randomly assigned 292 patients with chronic liver disease of diverse causes and platelet counts of less than 50,000 per cubic millimeter to receive eltrombopag, at a dose of 75 mg daily, or placebo for 14 days before a planned elective invasive procedure that was performed within 5 days after the last dose. The primary end point was the avoidance of a platelet transfusion before, during, and up to 7…
Effect of peginterferon alfa-2a on liver histology in chronic hepatitis C: a meta-analysis of individual patient data
2004
Multicenter randomized trials have shown that once-weekly pegylated interferon (peginterferon) alfa-2a is more efficacious than conventional interferon alfa-2a (IFN) in patients with chronic hepatitis C. We performed a meta-analysis of 1,013 previously untreated patients (from 3 randomized trials) with pretreatment and post-treatment liver biopsies to assess the differences between peginterferon alfa-2a and IFN in terms of their effects on liver histology. Reported values were standardized mean differences (SMD) between patients receiving peginterferon alfa-2a and those receiving IFN (post-treatment value minus baseline value for each group). We used a random-effects model to quantify the a…
Transcatheter arterial chemoembolization therapy for patients with hepatocellular carcinoma: a case-controlled study.
2005
Background & Aims: Transcatheter arterial chemoembolization (TACE) currently is used as a palliative treatment for patients with unresectable hepatocellular carcinoma (HCC), but its efficacy still is debated. Our aim was to assess the impact of TACE on patient survival and to identify prognostic factors for survival. Methods: Fifty-six cirrhotic patients with unresectable HCC undergoing at least :1 course of TACE were matched 1:1. for sex, age (in 5-year periods), parameters of Child-Pugh score, Okuda stage, and tumor type with a control group who had received only supportive care. Results: The 2 groups were comparable for cause of cirrhosis, alpha-fetoprotein serum levels, and Cancer of th…
Long-term albumin administration in decompensated cirrhosis (ANSWER): an open-label randomised trial
2018
Background Evidence is scarce on the efficacy of long-term human albumin (HA) administration in patients with decompensated cirrhosis. The human Albumin for the treatmeNt of aScites in patients With hEpatic ciRrhosis (ANSWER) study was designed to clarify this issue. Methods We did an investigator-initiated multicentre randomised, parallel, open-label, pragmatic trial in 33 academic and non-academic Italian hospitals. We randomly assigned patients with cirrhosis and uncomplicated ascites who were treated with anti-aldosteronic drugs (≥200 mg/day) and furosemide (≥25 mg/day) to receive either standard medical treatment (SMT) or SMT plus HA (40 g twice weekly for 2 weeks, and then 40 g weekly…
Prevention of Hepatocellular Carcinoma
2005
The accuracy and the reliability of well-recognized clinical, virologic, histologic, and molecular risk factors for HCC are still insufficient; thus, accurate risk prediction of developing cancer in individual patients remains an elusive goal. Future directions in chemprevention of HCC will be on the development of molecular risk models and of new chemopreventive agents. The design of targeted molecular therapies may need to be tailored to the specific molecular phenotype of a specific HCC. Studies examining multiple genes and proteins (genomics and proteomics) in the same HCCs will be required to evaluate this possibility thoroughly. In the setting of primary prevention, the epidemiologic …