Search results for "multivariate"

Pollution models and inverse distance weighting: some critical remarks

2013

International audience; When evaluating the impact of pollution, measurements from remote stations are often weighted by the inverse of distance raised to some nonnegative power (IDW). This is derived from Shepard's method of spatial interpolation (1968). The paper discusses the arbitrary character of the exponent of distance and the problem of monitoring stations that are close to the reference point. From elementary laws of physics, it is determined which exponent of distance should be chosen (or its upper bound) depending on the form of pollution encountered, such as radiant pollution (including radioactivity and sound), air pollution (plumes, puffs, and motionless clouds by using the cl…

Nitroarene hydrogenation catalysts based on Pd nanoparticles glued with PDA on inorganic supports: Multivariate Curve Resolution as an useful tool to…

2021

[EN] Two green catalysts based on Pd(0) nanoparticles (Pd NPs) anchored through PDA on porous silica and magnetite have been synthesized using a generalized simple and reproducible "two-step" methodology. Both catalysts were tested for a model reaction, the hydrogenation of 4-nitrophenol using NaBH4 as the hydrogenating agent, and especially good activity has been achieved in the case of the catalysts containing magnetite as inorganic core (Pd NPs-PDA@Fe3O4). We analyzed the effect associated with the catalyst separation method (centrifugation or magnetically) that affect to the distribution and aggregation degree of the Pd NPs. In addition, we also correlate the final catalyst morphology w…

Quels sont les patients diabétiques de type 2 à risque d’interactions médicamenteuses ?

2019

Fitness testing in tennis: Influence of anthropometric characteristics, physical performance, and functional test on serve velocity in professional p…

2021

The aims of this study were to examine the relationship between anthropometric variables, physical performance, and functional test with serve velocity regarding tennis players’ level and to design regression models that effectively predict serve velocity. A sample of sixteen male tennis players participated in this study (national level = 8, professional level = 7). Anthropometric measurements (body mass, height, body mass index and body segments) and physical test (hand strength, countermovement jump, jump on serve, and serve velocity) and functional test (medicine ball throw overhead and shot put) were performed. No differences in anthropometrics and physical test were found between nati…

The Cave of Vecchiuzzo: anthropology, paleopathology and hierarchy of the human group with a statistical overview (Petralia Sottana – Palermo, Italy)

2013

Lo scavo della Grotta del Vecchiuzzo fu il primo effettuato nelle Madonie (Sicilia centrooccidentale). Fin dalla sua scoperta avvenuta per mano di Collisani e Carapezza nel 1936, il ritrovamento di manufatti nel vano principale indicò che la grotta era stata abitata. Gli scavi, effettuati a partire dal 1937, indicarono che la grotta era stata adibita ad abitazione o forse a santuario e che era stata abitata intorno al terzo millennio a.C. I resti scheletrici, attribuiti ad almeno quindici individui, sono stati studiati dal punto di vista antropologico, antropometrico e paleopatologico, combinando metodologie tradizionali a quelle più moderne. Sui dati odontometrici raccolti è stata effettua…

Centrality in primate-parasite networks reveals the potential for the transmission of emerging infectious diseases to humans

2013

We thank Randi Griffin, Amy Pedersen, Rosa Menendez, Mark Lineham, and two anonymous reviewers for discussion and comments on a previous draft. This work was funded by the Spanish Ministry of Science (J.M.G. and M.V.), by the Junta de Andalucia (J.M.G.), and by National Science Foundation Grants DEB-0211908 and EF-0723939/0904359 (C.L.N.).

Multivariate denoising methods combining wavelets and principal component analysis for mass spectrometry data

2010

The identification of new diagnostic or prognostic biomarkers is one of the main aims of clinical cancer research. In recent years, there has been a growing interest in using mass spectrometry for the detection of such biomarkers. The MS signal resulting from MALDI-TOF measurements is contaminated by different sources of technical variations that can be removed by a prior pre-processing step. In particular, denoising makes it possible to remove the random noise contained in the signal. Wavelet methodology associated with thresholding is usually used for this purpose. In this study, we adapted two multivariate denoising methods that combine wavelets and PCA to MS data. The objective was to o…

Data Treatment and Error Analysis in Kinetics

2000

Methods of data treatment in kinetics are reviewed from a practical viewpoint. The equations to describe the kinetics of chemical reactions and the methodology to obtain the models are presented. Moreover, the integration methods that are needed for the simulation of complex reactions are explained, from the simple first-order reaction to the complex general mechanism. However, it is essential to know the main sources of error in data treatment in order to reduce their effects on the results. Stress is put on the analysis of the errors due to the simplification of complex models. The different factors that influence the kinetics of the reaction are reviewed. How to take advantage of the kin…

Effect of collagen substrates on proteomic modulation of breast cancer cells

2004

We have previously described the occurrence, in breast and colon cancer extra-cellular matrix, of an oncofoetal form of collagen, OF/LB, able to induce an increase in cell proliferation and motility in the breast cancer cell line 8701-BC. It also caused an increased amount of type V collagen which appears to exert an anti-proliferative effect on the same cells. The aim of the present study was to investigate, at the proteomic level, the effect of OF/LB and type V collagens used as substrates for neoplastic cell growth. Due to the complexity of a whole proteomic profile, a subset of significant protein classes was used to assess variations in protein expression levels. For this study we adop…

Missing value imputation in proximity extension assay-based targeted proteomics data

2020

Targeted proteomics utilizing antibody-based proximity extension assays provides sensitive and highly specific quantifications of plasma protein levels. Multivariate analysis of this data is hampered by frequent missing values (random or left censored), calling for imputation approaches. While appropriate missing-value imputation methods exist, benchmarks of their performance in targeted proteomics data are lacking. Here, we assessed the performance of two methods for imputation of values missing completely at random, the previously top-benchmarked ‘missForest’ and the recently published ‘GSimp’ method. Evaluation was accomplished by comparing imputed with remeasured relative concentrations…