Search results for "multivariate"
showing 10 items of 1520 documents
Hypoxia and hypothermia as rival agents of selection driving the evolution of viviparity in lizards
2017
[Aim]: The evolution of key innovations promotes adaptive radiations by opening access to new ecological opportunity. The acquisition of viviparity (live-bearing reproduction) has emerged as one such innovation explaining reptile proliferations into extreme climates. By evolving viviparity, females provide embryos with internally stable environments to complete development. The classical hypothesis suggests that natural selection for viviparity arises from low temperatures in cold climates, which promote prolonged egg retention in the mother's body. An alternative hypothesis proposes that declines in atmospheric oxygen at high elevations create natural selection for embryo retention to prov…
THE USE OF REGRESSION ANALYSIS IN MARKETING RESEARCH
2012
The purpose of the paper is to illustrate the applicability of the linear multiple regression model within a marketing research based on primary, quantitative data. The theoretical background of the developed regression model is the value-chain concept of relationship marketing. In this sense, the authors presume that the outcome variable of the model, the monetary value of one purchase, depends on the clients’ expectations regarding seven dimensions of the company’s offer. The paper is structured in two parts. In the first part, a brief literature review enumerates the main multivariate data analysis methods used in marketing research and describes the general linear multiple regression mo…
Intercultural Listening: Measuring Listening Concepts with the LCI-R
2016
Listening is an integral part of communication, yet more research is conducted on the speaker as opposed to the listener. Previous research established a general schema of listening as a concept-driven behavior with four factors (Imhof & Janusik, 2006). Further testing by Bodie (2010) confirmed the factor structure and reduced the number of items from 33 to 15 (LCI-R). What is not known is whether the constructs are consistent across cultures. This study investigates whether the LCI-R can fit independent data comprising samples from the United States, Europe, and Japan. Results show that the instrument can be used cross-culturally when listening concepts are of interest and need to be measu…
Beliefs and attitudes among Swedish workers regarding the risk of hearing loss
2004
The aim of this study was to develop an abridged version of the Tinnitus Questionnaire (TQ) to be used as a quick tool for the assessment of tinnitus-related psychological distress. Data from 351 inpatients and 122 outpatients with chronic tinnitus were used to analyse item statistics and psychometric properties. Twelve items with an optimal combination of high item-total correlations, reliability and sensitivity in assessing changes were selected for the Mini-TQ. Correlation with the full TQ was >0.90, and test-retest reliability was 0.89. Validity was confirmed by associations with general psychological symptom patterns. Treatment effects indicated by the Mini-TQ were slightly greater tha…
Circulating levels of 3-hydroxymyristate, a direct quantification of endotoxaemia in noninfected cirrhotic patients
2019
IF 4.5; International audience; Background & AimsThe quantification of lipopolysaccharide (LPS) in biological fluids is challenging. We aimed to measure plasma LPS concentration using a new method of direct quantification of 3‐hydroxymyristate (3‐HM), a lipid component of LPS, and to evaluate correlations between 3‐HM and markers of liver function, endothelial activation, portal hypertension and enterocyte damage.MethodsPlasma from 90 noninfected cirrhotic patients (30 Child‐Pugh [CP]‐A, 30 CP‐B, 30 CP‐C) was prospectively collected. The concentration of 3‐HM was determined by high‐performance liquid chromatography coupled with mass spectrometry.Results3‐HM levels were higher in CP‐C patien…
Relationship between Fertility Traits and Kinematics in Clusters of Boar Ejaculates
2021
The aim was to determine the relationship between kinematic parameters of boar spermatozoa and fertility rates of sow, as well as to assess the effect of sperm clusters on the fertility capacity of the ejaculate. Semen samples were collected from 11 sexually mature boars. Samples were analyzed by an ISAS®v1 CASA-Mot system for eight kinematic parameters. Ejaculate clusters were characterized using multivariate procedures, such as principal factors (PFs) analysis and clustering methods (the k-means model). Four different ejaculate clusters were identified from two kinematic PFs which involved linear trajectory and velocity. There were differences (p 0.05) between dam lines and ejaculate clus…
Dual therapy with peg-interferon and ribavirin in thalassemia major patients with chronic HCV infection: Is there still an indication?
2016
Background: Iron overload and hepatitis C virus (HCV) infection together can lead to chronic liver damage in thalassemia major (TM) patients. Aims: We investigated viral, genetic, and disease factors influencing sustained virological response (SVR) after peg-interferon and ribavirin therapy in TM patients with HCV infection. Methods: We analyzed 230 TM patients with HCV infection (mean age 36.0 ± 6.3 years; 59.1% genotype 1; 32.2% genotype 2; 3.4% genotype 3; and 5.3% genotype 4; 28.7% carried CC allele of rs12979860 in IL28B locus; 79.6% had chronic hepatitis and 20.4% cirrhosis; 63.5% naive and 36.5% previously treated with interferon alone) treated in 14 Italian centers. Results: By mul…
Improved noninvasive prediction of liver fibrosis by liver stiffness measurement in patients with nonalcoholic fatty liver disease accounting for con…
2016
Background and aims: Liver stiffness measurement (LSM) frequently overestimates the severity of liver fibrosis In Nonalcoholic Fatty Liver Disease (NAFLD). Controlled Attenuation Parameter (CAP) is a new parameter provided by the same machine used for LSM, and associated with both steatosis and BMI, the two factors mostly affecting LSM peformance in NAFLD. We aimed to determine wheter prediction of liver fibrosis by LSM in NAFLD patients is affected by CAP values. Methods: Patients (n=324) were assessed by clinical and histological (Kleiner score) features. LSM and CAP were performed using the M probe. CAP values were grouped by tertiles (lower from 132 to 298, middle from 299 to 338, highe…
Plasma Pro-C3 (N-terminal type III collagen propeptide) predicts fibrosis progression in patients with chronic hepatitis C.
2014
BACKGROUND & AIMS: Fibrogenesis results in release of certain extracellular matrix protein fragments into the circulation. We evaluated the diagnostic and prognostic performance of two novel serological markers, the precisely cleaved N-terminal propeptide of type III collagen (Pro-C3) and a peptide of helical collagen type III degradation (C3M), in chronic hepatitis C (CHC) patients. METHOD: Pro-C3 and C3M were measured by ELISA in plasma from CHC patients (n = 194) from a prior phase II antifibrotic trial (NCT00244751). Plasma samples and paired liver biopsies were obtained at baseline and after 1-year. Patients were stratified according to Ishak stages 2-4. Internal cross-validation w…
Simeprevir and daclatasvir for 12 or 24 weeks in treatment-naïve patients with hepatitis C virus genotype 1b and advanced liver disease
2017
Background & Aims: We investigated the efficacy and safety of simeprevir plus daclatasvir in treatment-naïve patients with chronic, genotype 1b hepatitis C virus infection and advanced liver disease, excluding patients with pre-defined NS5A resistance-associated substitutions. Methods: This phase II, open-label, single-arm, multicentre study included patients aged ≥18 years with advanced fibrosis or compensated cirrhosis (METAVIR F3/4). Patients with NS5A-Y93H or L31M/V resistance-associated substitutions at screening were excluded. Simeprevir (150 mg)+daclatasvir (60 mg) once daily was administered for 12 or 24 weeks; treatment could be extended to 24 weeks prior to or at the Week 12 v…