Search results for "Least-Squares Analysi"
showing 10 items of 66 documents
Topology testing of phylogenies using least squares methods
2006
[Background] The least squares (LS) method for constructing confidence sets of trees is closely related to LS tree building methods, in which the goodness of fit of the distances measured on the tree (patristic distances) to the observed distances between taxa is the criterion used for selecting the best topology. The generalized LS (GLS) method for topology testing is often frustrated by the computational difficulties in calculating the covariance matrix and its inverse, which in practice requires approximations. The weighted LS (WLS) allows for a more efficient albeit approximate calculation of the test statistic by ignoring the covariances between the distances.
Genetic diversity and trait genomic prediction in a pea diversity panel
2014
Background Pea (Pisum sativum L.), a major pulse crop grown for its protein-rich seeds, is an important component of agroecological cropping systems in diverse regions of the world. New breeding challenges imposed by global climate change and new regulations urge pea breeders to undertake more efficient methods of selection and better take advantage of the large genetic diversity present in the Pisum sativum genepool. Diversity studies conducted so far in pea used Simple Sequence Repeat (SSR) and Retrotransposon Based Insertion Polymorphism (RBIP) markers. Recently, SNP marker panels have been developed that will be useful for genetic diversity assessment and marker-assisted selection. Resu…
Fast and direct analysis of oxidation levels of oil-in-water emulsions using ATR-FTIR.
2019
International audience; Oxidation of omega-3 fatty acids is a major limitation on its enrichment in food and beverages. An efficient and simple method to monitor lipid oxidation in complex systems is essential to limit lipid oxidation during formulation and processing. Fish oil-in-water emulsions (20% v/v) were exposed to iron or free radical initiated oxidation. Conjugated dienes (CDs) were rapidly measured using a previously developed fat extraction method. Fourier transform infrared (FTIR) spectroscopy has been used to directly record chemical changes occurring during oxidation. Variations were noticed in different spectral regions despite the presence of broad water bands near 3400 and …
2-D mapping of skin chromophores in the spectral range 500 - 700 nm
2009
The multi-spectral imaging technique has been used for distant mapping of in-vivo skin chromophores by analyzing spectral data at each reflected image pixel and constructing 2-D maps of the relative concentrations of oxy-/deoxy-haemoglobin and melanin. Instead of using a broad visible-NIR spectral range, this study focuses on narrowed spectral band 500–700 nm, speeding-up the signal processing procedure. Regression analysis confirmed that superposition of three Gaussians is optimal analytic approximation for the oxy-haemoglobin absorption tabular spectrum in this spectral band, while superposition of two Gaussians fits well for deoxy-haemoglobin absorption and exponential function – for mel…
A new methodology based on functional principal component analysis tostudy postural stability post-stroke
2018
[EN] Background. A major goal in stroke rehabilitation is the establishment of more effective physical therapy techniques to recover postural stability. Functional Principal Component Analysis provides greater insight into recovery trends. However, when missing values exist, obtaining functional data presents some difficulties. The purpose of this study was to reveal an alternative technique for obtaining the Functional Principal Components without requiring the conversion to functional data beforehand and to investigate this methodology to determine the effect of specific physical therapy techniques in balance recovery trends in elderly subjects with hemiplegia post-stroke. Methods: A rand…
Postural control and balance in a cohort of healthy people living in Europe: An observational study
2018
Abstract In the past 20 years, posturography has been widely used in the medical field. This observational study aimed to report the values derived from posturography of a wide set of healthy subjects from various European countries using a plantar pressure platform and a standardized method of measurement. A random cluster sampling of 914 healthy subjects aged between 7.0 and 85.99 years, stratified by age, was carried out. To provide percentile values of our cohort, data were processed to obtain 3 curves corresponding to the following percentiles: 25th, 50th, 75th, and the interquartile range. Distance-weighted least squares method was used to represent the percentile on appropriate graph…
Understanding aroma release from model cheeses by a statistical multiblock approach on oral processing
2013
For human beings, the mouth is the first organ to perceive food and the different signalling events associated to food breakdown. These events are very complex and as such, their description necessitates combining different data sets. This study proposed an integrated approach to understand the relative contribution of main food oral processing events involved in aroma release during cheese consumption. In vivo aroma release was monitored on forty eight subjects who were asked to eat four different model cheeses varying in fat content and firmness and flavoured with ethyl propanoate and nonan-2-one. A multiblock partial least square regression was performed to explain aroma release from the…
Lipid-altering efficacy of switching to ezetimibe/simvastatin 10/20 mg versus rosuvastatin 10 mg in high-risk patients with and without metabolic syn…
2011
Metabolic syndrome (MetS) is a clustering of atherosclerotic coronary heart disease risk factors. This post-hoc analysis compared the effects of switching to ezetimibe/simvastatin 10/20 mg or rosuvastatin 10 mg in a cohort of 618 high-risk hypercholesterolaemic patients with ( n=368) and without ( n=217) MetS who had previously been on statin monotherapy. Patients were randomised 1:1 to double-blind ezetimibe/simvastatin 10/20 mg or rosuvastatin 10 mg for 6 weeks. Least squares mean percent change from baseline and 95% confidence intervals in lipid efficacy parameters were calculated for the population and within subgroups. Treatment with ezetimibe/simvastatin was significantly more effect…
Visual acuity and color discrimination in patients with cataracts.
2020
Color vision tests can give information about pathological changes in eye structures. The purpose of our research was to study the color vision sensitivity and visual acuity changes before and after cataract surgery. We used a saturated Farnsworth D15 color vision arrangement test to check color sensitivity changes in confusion line directions. The test is easily perceptible (essential to eldery patients), and it is possible to check color sensitivity changes in tritan, protan, and deutan confusion line directions. The results were analyzed in several ways: by summing the color differences between adjacent caps according to Bowman and averaging the color difference vectors according to Ving…
Resolvin D1 and miR‐146a are independent distinctive parameters in children with moderate and severe asthma
2020
To date, a large number of mediators and biomarkers have been detected in childhood asthma, with a potential role in monitoring the disease course. Lung function evaluation through spirometry, forced oscillation technique and multiple breath washout proved its role in asthma monitoring, especially for investigating small airway impairment in children with more severe symptoms. Recently, novel specialized pro-resolving mediators, such as resolvins and lipoxins, have been recognized as crucial in promoting the resolution of lung inflammation. Increasing evidence suggests that miRNAs are crucially entailed in asthma. Partial least squares discriminant analysis (plsDA) is a modern technique for…