Search results for "multivariate"
showing 10 items of 1520 documents
Updating semen analysis: a subpopulation approach
2019
An Information-Theoretic Framework to Map the Spatiotemporal Dynamics of the Scalp Electroencephalogram
2016
We present the first application of the emerging framework of information dynamics to the characterization of the electroencephalography (EEG) activity. The framework provides entropy-based measures of information storage (self entropy, SE) and information transfer (joint transfer entropy (TE) and partial TE), which are applied here to detect complex dynamics of individual EEG sensors and causal interactions between different sensors. The measures are implemented according to a model-free and fully multivariate formulation of the framework, allowing the detection of nonlinear dynamics and direct links. Moreover, to deal with the issue of volume conduction, a compensation for instantaneous e…
Lag-specific transfer entropy as a tool to assess cardiovascular and cardiorespiratory information transfer
2014
In the study of interacting physiological systems, model-free tools for time series analysis are fundamental to provide a proper description of how the coupling among systems arises from the multiple involved regulatory mechanisms. This study presents an approach which evaluates direction, magnitude, and exact timing of the information transfer between two time series belonging to a multivariate dataset. The approach performs a decomposition of the well-known transfer entropy (TE) which achieves 1) identifying, according to a lag-specific information-theoretic formulation of the concept of Granger causality, the set of time lags associated with significant information transfer, and 2) assig…
The development of a Spanish language version of the Worn Out scale of the General Well-Being Questionnaire (GWBQ).
2006
The paper describes the development of a short Spanish-language version of the General Well-Being Questionnaire (GWBQ; Cox & Gotts, 1987), based on the 12 items of its Worn Out scale. Research has shown the English-version Worn Out scale to be sensitive to aspects of the design and management of work. This study aimed to test its cross-cultural consistency in a Spanish-language workplace context. The data were collected from a sample of 229 workers in Valencia (Spain). Confirmatory Factor Analyses showed the factorial validity, reliability, and concurrent validity of the new Spanish version to be adequate. The sensitivity of the new measure to safety behavior and the reporting of accide…
Coping Strategies: Gender Differences and Development throughout Life Span
2012
Development during life-span implies to cope with stressful events, and this coping may be done with several strategies. It could be useful to know if these coping strategies differ as a consequence of personal characteristics. This work uses the Coping with Stress Questionnaire with this aim using a sample of 400 participants. Specifically, the effects of gender and age group (young people, middle age and elderly), as well as its interaction on coping strategies is studied. With regard to age, on one hand, it is hypothesised a decrement in the use of coping strategies centred in problem solving and social support seeking as age increases. On the other hand, the use of emotional coping is h…
Score to identify the severity of adult patients with influenza A (H1N1) 2009 virus infection at hospital admission
2012
The objective of this paper was to develop a prognostic index for severe complications among hospitalized patients with influenza A (H1N1) 2009 virus infection. We conducted a prospective observational cohort study of 618 inpatients with 2009 H1N1 virus infection admitted to 36 Spanish hospitals between July 2009 and February 2010. Risk factors evaluated included host-related factors and clinical data at admission. We developed a composite index of severe in-hospital complications (SIHC), which included: mortality, mechanical ventilation, septic shock, acute respiratory distress syndrome, and requirement for resuscitation maneuvers. Six factors were independently associated with SIHC: age >…
Analysis of potential dynamic concealed factors in the difficulty of lower third molar extraction
2015
Background The purpose of this study was to identify potential concealed variables associated with the difficulty of lower third molar (M3) extractions. Material and Methods To address the research purpose, we implemented a prospective study and enrolled a sample of subjects presenting for M3 removal. Predictor variables were categorized into Group-I and Group-II, based on predetermined criteria. The primary outcome variable was the difficulty of extraction, measured as extraction time. Appropriate univariate and multivariate statistics were computed using ordinal logistic regression. Results The sample comprised of 1235 subjects with a mean age of 29.49 +/- 8.92 years in Group-I and 26.20 …
Risk factors for temporomandibular disorder: Binary logistic regression analysis
2013
Objectives: To analyze the influence of socioeconomic and demographic factors (gender, economic class, age and marital status) on the occurrence of temporomandibular disorder. Study Design: One hundred individuals from urban areas in the city of Recife (Brazil) registered at Family Health Units was examined using Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/ TMD) which addresses myofascial pain and joint problems (disc displacement, arthralgia, osteoarthritis and oeste - oarthrosis). The Brazilian Economic Classification Criteria (CCEB) was used for the collection of socioeconomic and demographic data. Then, it was categorized as Class A (high social class…
High-resolution HLA matching in hematopoietic stem cell transplantation: a retrospective collaborative analysis.
2013
To validate current donor selection strategies based on previous international studies, we retrospectively analyzed 2646 transplantations performed for hematologic malignancies in 28 German transplant centers. Donors and recipients were high resolution typed for HLA-A, -B, -C, -DRB1, and -DQB1. The highest mortality in overall survival analysis was seen for HLA-A, -B, and DRB1 mismatches. HLA-DQB1 mismatched cases showed a trend toward higher mortality, mostly due to HLA-DQB1 antigen disparities. HLA incompatibilities at >1 locus showed additive detrimental effects. HLA mismatching had no significant effect on relapse incidence and primary graft failure. Graft source had no impact on surviv…
Maternal copper status and neuropsychological development in infants and preschool children.
2019
Introduction: Copper (Cu) is an essential element involved in biological processes; however, excessive Cu could be harmful because of its reactive nature. Very few studies have evaluated its potential neurotoxic effects. We aimed to evaluate the association between maternal Cu levels and children's neuropsychological development. Methods: Study subjects were mother-child pairs from the Spanish INMA (i.e. Childhood and Environment) Project. Cu was measured by inductively coupled plasma mass spectrometry in serum samples taken at the first trimester of pregnancy (2003-2005). Neuropsychological development was assessed using the Bayley Scales of Infant Development (BSID) at 12 months (n = 651) a…