Search results for "Analysis of covariance"
showing 10 items of 15 documents
Can Word Puzzles be Tailored to Improve Different Dimensions of Verbal Fluency? A Report of an Intervention Study
2016
Verbal fluency is commonly used as a proxy measure of executive functioning, as it involves cognitive flexibility, working memory, and inhibitory control. Previous research has demonstrated that crosswords can be a useful means of improving verbal fluency, results consistent with the cognitive reserve hypothesis; the form of verbal fluency affected has, however, differed across studies. The present study sought to assess the extent to which it was possible to target phonemic (PVF) and semantic verbal fluency (SVF) separately through word puzzles designed to focus on semantic/thematic and structural clues respectively. Fifty-three university students were randomly assigned to one of three gr…
Accommodative stimulus-response curves to low-pass filtered natural images
2018
To assess how the monocular steady-state accommodative stimulus-response curve is modified when viewing low-pass filtered natural images. Eighteen adult subjects participated in the study. The accommodative stimulus-response curve was objectively assessed by means of a Hartmann-Shack wavefront sensor. Measurements were taken at different accommodative demands. Target images were low-pass filtered versions of a natural image that were obtained applying different digital spatial filters that limited the spatial frequency content of the natural image. Cutoff spatial frequencies were set at 30, 21, and 15 cycles per degree (cy/deg). Mean data obtained for each target were fitted to linear model…
Metabolic connectivity as index of verbal working memory
2015
Positron emission tomography (PET) data are commonly analyzed in terms of regional intensity, while covariant information is not taken into account. Here, we searched for network correlates of healthy cognitive function in resting state PET data. PET with [18F]-fluorodeoxyglucose and a test of verbal working memory (WM) were administered to 35 young healthy adults. Metabolic connectivity was modeled at a group level using sparse inverse covariance estimation. Among 13 WM-relevant Brodmann areas (BAs), 6 appeared to be robustly connected. Connectivity within this network was significantly stronger in subjects with above-median WM performance. In respect to regional intensity, i.e., metaboli…
Comparative Study of the Perceived Quality of Life of Patients in Treatment for Cocaine and Heroin Dependence in Spain: Differences by Gender and Tim…
2014
This is a cross-sectional study in which we compared the perceived quality of life (QoL) of patients receiving outpatient treatment for cocaine (n = 727) and heroin dependence (n = 469), by analyzing differences by gender and time in treatment. Participants were recruited from addictive behavior centers in Spain in 2004. The World Health Organization Quality of Life Assessment Instrument (WHOQOL-Bref) was used as a measure. Analysis of covariance and multivariate linear regression were used. This study shows the relevance of considering the role of gender in QoL studies, and the need to evaluate the effectiveness of treatment in the improvement of QoL. Limitations of the study were noted.
Effects of power resistance training program with elastic bands on body composition, muscle strength and physical function in older women
2020
The aim of this study was to investigate the effects of a power-strength resistance program with elastic bands on body composition, physical function, and muscle strength in older women. For such purpose, a randomized controlled trial with a pre-post-intervention design was conducted. Thus, 58 healthy, physically independent, sedentary women, aged 65-85 years, were randomly allocated to the intervention (n = 28) or control group (n = 30). Measurements of body composition (total mass, total fat mass, total skeletal-muscle mass, and body fat percentage), isokinetic muscle strength of knee flexors and extensors (at 60º/second and 180º/second), and physical performance (flexibility, agility/dyn…
Error estimation and reduction with cross correlations
2010
Besides the well-known effect of autocorrelations in time series of Monte Carlo simulation data resulting from the underlying Markov process, using the same data pool for computing various estimates entails additional cross correlations. This effect, if not properly taken into account, leads to systematically wrong error estimates for combined quantities. Using a straightforward recipe of data analysis employing the jackknife or similar resampling techniques, such problems can be avoided. In addition, a covariance analysis allows for the formulation of optimal estimators with often significantly reduced variance as compared to more conventional averages.
Investigating the level of significance of the coherence function in cardiovascular variability analysis
2002
Although the presence of significant coupling between cardiovascular variability series is usually verified according to the threshold value of 0.5 in the coherence function (CF), spectral estimator parameters should also be considered. In this study, the surrogate data technique was introduced to define the level of significance of the CF. The proposed method determined a frequency-dependent threshold over which the hypothesis of zero coherence was rejected. The weighted covariance method and the autoregressive method were used to estimate the CF on simulated series with different degrees of linear coupling and on real cardiovascular data. The threshold was dependent on the type and parame…
Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral pal…
2020
Graphical abstract
Menarcheal age and socio-economic factors in Poland
2005
Menarcheal age is the most important measure of sexual maturation in girls and a sensitive indicator of environmental conditions during childhood.The study analysed the association between age at menarche and socio-economic characteristics (urbanization, population size, education of parents and number of children in the family).Questionnaire data were collected from 3271 female schoolchildren born between 1981 and 1984, living in three provinces of southern Poland. Menarcheal age was estimated by the recall method and based on the date of menarche given by the study participants. ANCOVA and multiple regression analyses were applied to test statistical significance of differences between gr…
Effects of progressive resistance training on physical disability among older community-dwelling people with history of hip fracture
2012
Background and aims: Hip fracture is a common trauma in older people, and often leads to decreased muscle strength and increased physical disability. This randomized controlled trial examined whether three months of progressive resistance training (PRT) can reduce physical disability among older people with a history of hip fracture. Methods: A population-based sample of 60-85-year-old community-dwelling persons, with hip fractures sustained on average three years earlier, were enrolled in the study. Of 78 people participating in laboratory assessments, those without contraindications for participation in resistance training were randomly assigned to a training group (TG, n=22) or a control…