Search results for "Component analysis"
showing 10 items of 562 documents
Sperm kinematic, head morphometric and kinetic-morphometric subpopulations in the blue fox (Alopex lagopus)
2016
This work provides information on the blue fox ejaculated sperm quality needed for seminal dose calculations. Twenty semen samples, obtained by masturbation, were analyzed for kinematic and morphometric parameters by using CASA-Mot and CASA-Morph system and principal component (PC) analysis. For motility, eight kinematic parameters were evaluated, which were reduced to PC1, related to linear variables, and PC2, related to oscillatory movement. The whole population was divided into three independent subpopulations: SP1, fast cells with linear movement; SP2, slow cells and nonoscillatory motility; and SP3, medium speed cells and oscillatory movement. In almost all cases, the subpopulation dis…
Event-related potentials in newborns with and without familial risk for dyslexia: principal component analysis reveals differences between the groups
2003
Differences revealed by factor scores extracted by principal component analysis (PCA) from event-related potential (ERP) data of newborns with and without familial risk for dyslexia were examined and compared to results obtained by using original averaged ERPs. ERPs to consonant-vowel syllables (synthetic /ba/, /da/, /ga/; and natural /paa/, /taa/, /kaa/) were recorded from 26 at-risk and 23 control 1-7 day-old infants. The stimuli were presented equiprobably and with interstimulus intervals varying at random from 3,910 to 7,285 ms. Statistically significant between-group differences were found to be relatively similar irrespective of the methods of analysis (original ERPs vs. factor scores…
Neurofunctional correlates of attention rehabilitation in Parkinson's disease: an explorative study
2014
The effectiveness of cognitive rehabilitation (CR) in Parkinson’s disease (PD) is in its relative infancy, and nowadays there is insufficient information to support evidence-based clinical protocols. This study is aimed at testing a validated therapeutic strategy characterized by intensive computer-based attention-training program tailored to attention deficits. We further investigated the presence of synaptic plasticity by means of functional magnetic resonance imaging (fMRI). Using a randomized controlled study, we enrolled eight PD patients who underwent a CR program (Experimental group) and seven clinically/demographically-matched PD patients who underwent a placebo intervention (Contro…
Functional principal component analysis as a new methodology for the analysis of the impact of two rehabilitation protocols in functional recovery af…
2014
[EN] Background: This study addressed the problem of evaluating the effectiveness of two protocols of physiotherapy for functional recovery after stroke. In particular, the study explored the use of Functional Principal Component Analysis (FPCA), a multivariate data analysis in order to assess and clarify the process of regaining independence after stroke. Methods: A randomized double-blind controlled trial was performed. Thirteen subjects with residual hemiparesis after a single stroke episode were measured in both in- and outpatient settings at a district hospital. All subjects were able to walk before suffering the stroke and were hemodynamically stable within the first week after stroke…
The role of fear-avoidance cognitions and behaviors in patients with chronic tinnitus.
2012
The current study investigated the role of fear-avoidance-a concept from chronic pain research-in chronic tinnitus. A self-report measure the "Tinnitus Fear-Avoidance Cognitions and Behaviors Scale (T-FAS)" was developed and validated. Furthermore, the role of fear-avoidance behavior as mediator of the relationship between anxiety sensitivity and tinnitus handicap was investigated. From a clinical setting, N = 373 patients with chronic tinnitus completed questionnaires assessing tinnitus handicap (Tinnitus Handicap Inventory), anxiety, depression (Hospital Anxiety and Depression Scale), anxiety sensitivity (Anxiety Sensitivity Index-3), personality factors (Big Five Inventory-10), and fear-…
Study of the recovery patterns of elderly subacute stroke patients in an interdisciplinary neurorehabilitation unit
2015
Background This study seeks to establish the facts of the improvement over time in elderly poststroke patients. Methods A retrospective study was performed with regard to 106 subacute stroke patients aged older than 65 years, who were treated in an interdisciplinary neurorehabilitation unit. Three assessment points were established (on admission, 6 months post-onset, and 12 months post-onset), with the scores relative to 10 assessment scales having been collected at each point. Results By means of a principal component analysis, a first component was obtained, which is taken to represent a combined index of the 10 scales and to express the overall health status of the patient. An analysis o…
Genome-Wide Expression Profiles in Very Low Birth Weight Infants With Neonatal Sepsis
2014
BACKGROUND: Bacterial sepsis is associated with high morbidity and mortality in preterm infants. However, diagnosis of sepsis and identification of the causative agent remains challenging. Our aim was to determine genome-wide expression profiles of very low birth weight (VLBW) infants with and without bacterial sepsis and assess differences. METHODS: This was a prospective observational double-cohort study conducted in VLBW (<1500 g) infants with culture-positive bacterial sepsis and non-septic matched controls. Blood samples were collected as soon as clinical signs of sepsis were identified and before antibiotics were initiated. Total RNA was processed for genome-wide expression an…
Puma (Puma concolor) epididymal sperm morphometry
2016
The Andean puma (Puma concolor) has not been widely studied, particularly in reference to its semen characteristics. The aim of the present study was to define the morphometry of puma sperm heads and classify their subpopulations by cluster analysis. Samples were recovered postmortem from two epididymides from one animal and prepared for morphological observation after staining with the Hemacolor kit. Morphometric data were obtained from 581 spermatozoa using a CASA-Morph system, rendering 13 morphometric parameters. The principal component (PC) analysis was performed followed by cluster analysis for the establishment of subpopulations. Two PC components were obtained, the first related to …
Development and Validation of the Questionnaire of Academic Stress in Secondary Education: Structure, Reliability and Nomological Validity
2018
This study presents the validation process of the Questionnaire on Academic Stress in Secondary Education (QASSE) designed to assess the wide variety of school sources and situations related to academic stress in adolescence, and their relationship with students&rsquo
Improving Isolation of Blindly Separated Sources Using Time-Frequency Masking
2008
A refinement technique based on time-frequency masking is proposed to improve source isolation in blind audio source separation algorithms. The refinement technique uses an energy-normalized source-to-interference ratio in order to identify and eliminate interfering energy from the extracted sources. Some examples using this refinement method with different separation algorithms are discussed. The results show that source isolation can be significantly enhanced with negligible degradation of the separated sources.