Microbiological and molecular characterization of nosocomial and community Staphylococcus aureus isolates

2010 ◽  
Vol 139 (4) ◽  
pp. 613-622 ◽  
Author(s):  
F. SCAZZOCCHIO ◽  
L. AQUILANTI ◽  
C. TABACCHINI ◽  
V. IEBBA ◽  
C. PASSARIELLO
Keyword(s):  
Staphylococcus Aureus ◽  
Partial Least Square ◽  
Least Square ◽  
Clear Correlation ◽  
Time Interval ◽  
Surrounding Area ◽  
Genetic Profiles ◽  
Hospital Acquired

SUMMARYThis study aimed to evaluate the incidence of Staphylococcus aureus infections in different departments of Belcolle Hospital in Viterbo and the surrounding area between January 2003 and June 2008. Isolates of methicillin-resistant S. aureus (MRSA) recovered in this time interval were characterized by microbiological and molecular methods to evaluate the reliability of simple criteria to distinguish between hospital-acquired and community-acquired isolates. MRSA accounted for 33% of all S. aureus, with a significantly higher prevalence in isolates from nosocomial infections. MRSA isolates were assayed by PCR for the presence of 13 genes associated with virulence, agr type and SCCmec type. Cumulative data were analysed by partial least square discriminant analysis and a clear correlation was demonstrated between genetic profiles and classification of isolates as hospital or community acquired according to simple temporal criteria. Nosocomial MRSA isolates from blood samples showed significantly higher genetic diversity than other nosocomial isolates. Our data confirm the existence of significant differences between community- and hospital-acquired MRSA isolates.

Characterization of Biodiesel by Infrared Spectroscopy with Partial Least Square Discriminant Analysis

2017 ◽  
Vol 50 (13) ◽  
pp. 2117-2128 ◽  
Author(s):  
Ademar Domingos Viagem Máquina ◽  
Letícia Maria de Souza ◽  
Lucas Caixeta Gontijo ◽  
Douglas Queiroz Santos ◽  
Waldomiro Borges Neto
Keyword(s):  
Infrared Spectroscopy ◽  
Discriminant Analysis ◽  
Partial Least Square ◽  
Least Square

Classification of Automobile Lubricant by Near-Infrared Spectroscopy Combined with Machine Classification

2011 ◽  
Vol 460-461 ◽  
pp. 667-672
Author(s):  
Yun Zhao ◽  
Xing Xu ◽  
Yong He
Keyword(s):  
Near Infrared ◽  
Prediction Models ◽  
Nir Spectroscopy ◽  
Partial Least Square ◽  
Least Square ◽  
Support Vector ◽  
Training Set ◽  
Test Set ◽  
Svm Model

The main objective of this paper is to classify four kinds of automobile lubricant by near-infrared (NIR) spectral technology and to observe whether NIR spectroscopy could be used for predicting water content. Principle component analysis (PCA) was applied to reduce the information from the spectral data and first two PCs were used to cluster the samples. Partial least square (PLS), least square support vector machine (LS-SVM), and Gaussian processes classification (GPC) were employed to develop prediction models. There were 120 samples for training set and test set. Two LS-SVM models with first five PCs and first six PCs were built, respectively, and accuracy of the model with five PCs is adequate with less calculation. The results from the experiment indicate that the LS-SVM model outperforms the PLS model and GPC model outperforms the LS-SVM model.

Structural response reconstruction using inclinometer and velocimeter

2019 ◽  
Author(s):  
Yixian Li ◽  
Limin Sun ◽  
Wei Zhang
Keyword(s):  
Balance Equation ◽  
Partial Least Square ◽  
Least Square ◽  
Partial Least Square Regression ◽  
Model Parameters ◽  
Time Interval ◽  
Dynamic Distortion ◽  
Nodal Force ◽  
Least Square Regression ◽  
Response Reconstruction

<p>This paper proposes a structural dynamic response reconstruction algorithm using inclinometer and velocimeter, combining in-situ measured data with finite element model. Using a small number of inclination and velocity data, the dynamic deflection, rotation, and strain at any position of a structure can be estimated. Firstly, static structural deformation estimation method is introduced as the base. The key content is to solve an underdetermined static equation using partial least square regression and calculate equivalent nodal force. By rewriting dynamic balance equation into state space, an equivalent static balance equation is obtained. Use partial least square regression to solve this equation and compute time histogram of equivalent nodal force, in which dynamic distortion exists. Accordingly, a frequency response-based time interval correction method is proposed to correct the dynamic distortion and is validated to be effective. Finally, numerical simulation is adopted to validate accuracy and robustness of the algorithm through changing parameters including sampling time interval, input frequency components, model parameters and introducing measurement noise. All results have demonstrated that the algorithm is of good adaptability to various changes and maintains high accuracy.</p>

Classification of Three Green Tea Varieties by Micellar Electrokinetic Electrophoresis-Laser Induced Fluorescence and Pattern Recognition Methods

2012 ◽  
Vol 554-556 ◽  
pp. 1289-1292
Author(s):  
Neng Sheng Ye ◽  
Ya Li Xie ◽  
Chang Liu ◽  
Jian Li
Keyword(s):  
Cluster Analysis ◽  
Pattern Recognition ◽  
Discriminant Analysis ◽  
Laser Induced Fluorescence ◽  
Partial Least Square ◽  
Least Square ◽  
Sodium Borate ◽  
Laser Induced Fluorescence Detection ◽  
Pattern Recognition Methods

A micellar electrokinetic electrophoresis-laser induced fluorescence detection (MEKC-LIF) method was applied for the profiling of native fluorescence in three different kinds of Chinese green teas. The running buffer was 100 mM sodium borate (pH9.8) containing 20 mM SDS, and tea infusion was injected at the pressure of 0.5 psi for 5 seconds. The applied voltage was set at 25 kV, and the excited wavelength was 488 nm, and the detected wavelength was 520 nm. Ten tea samples were collected and analyzed by the developed method. Eighteen common peaks in the MEKC-LIF profiling of green teas were selected and these samples were classified into 3 groups by cluster analysis and partial least square discriminant analysis (PLS-DA). Our primary results indicated that the developed method could be applied for the classification of three different Chinese green teas

Metabolic characterization of amniotic fluids of fetuses with enlarged nuchal translucency

2019 ◽  
Vol 47 (3) ◽  
pp. 311-318 ◽  
Author(s):  
Ambra Iuculano ◽  
Federica Murgia ◽  
Cristina Peddes ◽  
Maria Laura Santoru ◽  
Laura Tronci ◽  
...  
Keyword(s):  
High Performance ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Partial Least Square ◽  
Least Square ◽  
Proton Nuclear Magnetic Resonance ◽  
Control Group ◽  
Aneuploidy Screening ◽  
H Nmr

Abstract Background In prenatal diagnosis, a thickened nuchal translucency (NT) is one of the most sensitive and specific markers for several defects but it may also be found in 5% of healthy fetuses. The pathophysiological causes that lead to an increase in NT are not yet fully understood. Metabolomics represents a new promising approach, useful for studying different metabolites in biological organisms in response to environmental stressors. The aim of our study was to investigate the metabolomic profile of the amniotic fluid samples (AFS) of euploid fetuses with enlarged nuchal translucency (ENT) compared to a control group (C group). Methods This study was carried out on a group of women who underwent second-trimester amniocentesis for advanced maternal age (C group) or for NT ≥95th percentile (ENT group) found during first-trimester aneuploidy screening. AFS were analyzed with proton nuclear magnetic resonance (1H-NMR) and high-performance liquid chromatography (HPLC), and subsequent multivariate and univariate statistical analyses were conducted, followed by pathway analysis. Results In total, 67 AFS from the C group and 23 from the ENT group were analyzed. Partial least square discriminate analysis was carried out (R2X=0.784, R2Y=0.658, Q2=0.622, P<0.0001). A different metabolic profile was observed in the ENT group compared with the C group, suggesting an energetic shift to a glycolytic phenotype in an oxidative environment in the ENT group compared to the C group. Conclusion Metabolomic studies enable the identification of metabolic alterations occurring in fetuses with ENT. These findings may provide a new basis for better understanding the pathophysiological mechanisms in this prenatal phenomenon.

Variable selection in classification of environmental soil samples for partial least square and neural network models

2001 ◽  
Vol 446 (1-2) ◽  
pp. 231-242 ◽  
Author(s):  
Ziad Ramadan ◽  
Xin-Hua Song ◽  
Philip K Hopke ◽  
Mara J Johnson ◽  
Kate M Scow
Keyword(s):  
Neural Network ◽  
Variable Selection ◽  
Network Models ◽  
Soil Samples ◽  
Partial Least Square ◽  
Least Square ◽  
Neural Network Models

scholarly journals Metabolomic Characterization of Commercial, Old, and Red-Fleshed Apple Varieties

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 378
Author(s):  
Adriana Teresa Ceci ◽  
Michele Bassi ◽  
Walter Guerra ◽  
Michael Oberhuber ◽  
Peter Robatscher ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
Polyphenolic Compounds ◽  
Partial Least Square ◽  
Least Square ◽  
Antioxidant Compounds ◽  
Apple Varieties ◽  
Apple Cultivars ◽  
Health Features

In this study, a metabolomic investigation was presented to correlate single polyphenolic compounds in apple pulp with quality characteristics such as antioxidant activity and content of phenolic compounds and anthocyanins in apple skin. Since the concentration of these compounds is influenced by environmental factors, the twenty-two apple cultivars originate from the same site. The polyphenolic compounds were analyzed by ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS). The antioxidant activity, phenolic content, and anthocyanins were evaluated on the sunny and the shady sides of apple skin by spectrometric assays. In old apple varieties, the measured parameters were higher than in the commercial and red-fleshed varieties. By contrast, the profile of flavan-3-ols and anthocyanins was variable amongst commercial and red-fleshed varieties. The partial least square (PLS) method was applied to investigate the association between the skin proprieties and the metabolic profile of the pulp. The highest coefficients of determination in prediction (Q2) were obtained for compounds quantified in old cultivars. These results provided information to define the old apple varieties as a reliable group based on the pathway of the antioxidant compounds and anthocyanins content. Our results show the possibility to find cultivars with promising health features based on their content of polyphenols suitable for commercialization or breeding.

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