Search results for "Reproducibility"
showing 10 items of 1976 documents
Evaluation of the effect of chance correlations on variable selection using Partial Least Squares -Discriminant Analysis
2013
Variable subset selection is often mandatory in high throughput metabolomics and proteomics. However, depending on the variable to sample ratio there is a significant susceptibility of variable selection towards chance correlations. The evaluation of the predictive capabilities of PLSDA models estimated by cross-validation after feature selection provides overly optimistic results if the selection is performed on the entire set and no external validation set is available. In this work, a simulation of the statistical null hypothesis is proposed to test whether the discrimination capability of a PLSDA model after variable selection estimated by cross-validation is statistically higher than t…
Comparison of a Manual and an Automated Method to Estimate the Number of Uterine Eggs in Anisakid Nematodes: To Coulter or Not to Coulter. Is That th…
2007
Studies reporting numbers of eggs in vagina and utero in nematodes often give little information of the technique used for the estimations. This situation hampers comparison among studies, because, so far, differences in estimations provided by different techniques have not been assessed. This note examines whether a manual method based on visual counts in aliquots and an automated method using a Coulter counter yield equivalent estimations of egg numbers in vagina and utero of 3 anisakid nematode species (Anisakis simplex, Pseudoterranova decipiens, and Contracaecum osculatum). The number of eggs from 50 females per nematode species was estimated using both techniques. The automated and ma…
Do vitamin E supplements in diets for laboratory animals jeopardize findings in animal models of disease?
1999
Abstract Vitamin E has been supplemented to the diets of farm animals to improve fertility, health, growth rates and quality of animal products. Because of the positive experience obtained in farm animals, vitamin E has been added in increasing amounts to the diets of laboratory animals. Today, vitamin E levels in standard rodent maintenance diets range from 30 mg/kg (France, United States), 90–120 mg/kg (Netherlands, United Kingdom) to as much as 200 mg/kg (Germany). While increasing fertility and health of laboratory animals, these vitamin E supplements affect diverse pathophysiological conditions and thus the outcome of animal models of disease. Because of the large variability of vitami…
In-Depth Characterization of Viral Isolates from Plasma and Cells Compared with Plasma Circulating Quasispecies in Early HIV-1 Infection
2012
Background The use of in vitro models to unravel the phenotypic characteristics of circulating viral variants is key to understanding HIV-1 pathogenesis but limited by the availability of primary viral isolates from biological samples. However, overall in vivo genetic variability of HIV-1 within a subject may not be reflected in the viable viral population obtained after isolation. Although several studies have tried to determine whether viral populations expanded in vitro are representative of in vivo findings, the answer remains unclear due to the reduced number of clonal sequences analyzed or samples compared. In order to overcome previous experimental limitations, here we applied Deep P…
Applying pattern recognition methods plus quantum and physico-chemical molecular descriptors to analyze the anabolic activity of structurally diverse…
2008
The great cost associated with the development of new anabolic-androgenic steroid (AASs) makes necessary the development of computational methods that shorten the drug discovery pipeline. Toward this end, quantum, and physicochemical molecular descriptors, plus linear discriminant analysis (LDA) were used to analyze the anabolic/androgenic activity of structurally diverse steroids and to discover novel AASs, as well as also to give a structural interpretation of their anabolic-androgenic ratio (AAR). The obtained models are able to correctly classify 91.67% (86.27%) of the AASs in the training (test) sets, respectively. The results of predictions on the 10% full-out cross-validation test al…
Can Applications Designed to Evaluate Visual Function Be Used in Different iPads?
2018
SIGNIFICANCE: Apple devices could be suitable for vision tests, provided that the test has been correctly adapted to the device, after considering the spatial and colorimetric characterization of the screen. PURPOSE: The majority of vision applications has not been developed by vision or colorimetry experts and suffers from conceptual and design errors that may lead average users to an erroneous assessment of their visual capabilities. The reliability of vision tests depends on the accurate generation of the necessary visual stimuli in a particular device. Our aim was to ascertain whether a given color test, designed for a colorimetrically characterized device, might be used in another simi…
Alcohol consumption among students and its relationship with nutritional intake: a cross-sectional study
2020
AbstractObjective:Excessive alcohol consumption during reproductive years may impact the integrity of developing eggs and sperm, potentially affecting the life-long health of future children. Inadequate diets could aggravate these preconception effects of alcohol. The aim of the present study was to assess the prevalence of excessive alcohol consumption and explore whether weekly alcohol intake is associated with energy and nutrient intake and adequacy of micronutrient intake among students.Design:Cross-sectional survey using a validated and reproducibility-tested FFQ.Setting:University of Agder, Norway, in 2018.Participants:622 students (71 % female).Results:More than 80 % reported having …
Classification of diabetes-related retinal diseases using a deep learning approach in optical coherence tomography
2019
Background and objectives: Spectral Domain Optical Coherence Tomography (SD-OCT) is a volumetric imaging technique that allows measuring patterns between layers such as small amounts of fluid. Since 2012, automatic medical image analysis performance has steadily increased through the use of deep learning models that automatically learn relevant features for specific tasks, instead of designing visual features manually. Nevertheless, providing insights and interpretation of the predictions made by the model is still a challenge. This paper describes a deep learning model able to detect medically interpretable information in relevant images from a volume to classify diabetes-related retinal d…
Comparison of higher order aberrations measured by NIDEK OPD-Scan dynamic skiascopy and Zeiss WASCA Hartmann-Shack aberrometers.
2008
<h4>PURPOSE</h4><p>To compare the measurement of wavefront aberrations in non-cyclopleged human eyes with Hartmann-Shack and dynamic skiascopy wavefront analyzers.</p> <h4>METHODS</h4><p>Eighty eyes of 40 healthy young adults (19 men, 21 women; mean age 20.8±2.5 years) with refractive errors ranging from +1.50 to –9.75 diopters (D) sphere and up to 1.75 D cylinder (mean spherical equivalent refraction –2.12±2.69 D) were examined with the Zeiss/Meditec WASCA and NIDEK OPD-Scan wavefront analyzers and with the Nippon SRW5000 binocular, open-field autorefractor without the instillation of antimuscarinic agents. Three measurements were taken with each s…
Authentication and identification of Saccharomyces cerevisiae‘flor’ yeast races involved in sherry ageing
2004
Yeasts involved in velum formation during biological ageing of sherry wine have to date been classified into four races of Saccharomyces cerevisiae (beticus, cheresiensis, montuliensis, rouxii) according to their abilities to ferment different sugars. It has been proposed that race succession during biological ageing is essential for the development of the organoleptical properties of sherry wines. In this work we studied the physiological characteristics, the molecular differentiation and the phylogenetic relationships of the four races employing type and reference strains from culture collections and natural environments. Using restriction analysis of the ribosomal region that includes th…