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Results for “correlation matrix”

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PubMedDate not supplied

[Helminthiases among the population of northwestern Siberia. 1. Opisthorchiasis and mixed invasion in the native inhabitants of the Ob River basin and their clinical course].

The use of multifactor statistic analysis for screening population of the northern part of the Ob river basin for helminthiasis allowed the authors to reveal a significant feedback between manifested opisthorchiasis and other types of this disease course in both sexes. The main component analysis indicates that the tentatively control group of males is presented by adolescents (14-17 years old) who are likely to be infected with Opisthorchis without evidence of its clinical manifestations. The correlation analysis demonstrated also a direct relationship between the age and manifest opisthorchiasis, as well as double mixed invasion of males (r-0.15 and 0.26, p less than 0.05 and 0.01, respectively). The first three main components explain about 55% variance in the correlation matrix of initial parameters and allow to reveal the variance source, taking into account, along with differentiation of 4 groups of opisthorchiasis patients, also the age- and sex-dependent combination of opisthorchiasis with other helminthic invasions.

Adolescent↗

PubMedDate not supplied

Statistical analysis of white blood cell data directed to the detection of malignancy in untreated patients.

A training set of 90 malignant cases (positives) and 61 non-malignant cases (negatives) was used to determine statistics for five parameters based on white blood cell analysis. The statistics used were thresholds, differences between the positive and negative means, and the weighted correlation matrix. Three decision methods using these statistics were then applied to a test set of 90 positives and 60 negatives. The percentage of correct decisions ranged from 98.67 per cent for parameter 3. The best result using only parameters capable of recognition by an automated apparatus was 94.00 per cent.

Cytodiagnosis↗

PubMed1989

[Prognostically significant indices of the bioenergetic metabolism of the brain in experimental ischemia (a NMR spectroscopic study)].

Initial levels of phosphate brain metabolites were measured using 31P NMR spectroscopy in rats which subsequently died or survived under bilateral ligation of common carotid arteries. A multidimensional analysis was applied. In the rats which died after the brain ischemia: (1), NAD and NADH+ concentrations were much higher than those of creatine phosphate or ATP (i.e. baseline dysbalance existed between the systems of hydrogen acceptors and major macroergic substances); (2), the force of relationships between parameters of NMR spectra in each correlation matrix were 10 times higher and the variability of elements in each matrix was significantly lower than those of the surviving group. These regularities can be used in detection of special groups at high professional risk and in designing individual procedures of prevention and treatment of cerebral circulation disorders. The data are valuable in terms of development of drugs which would correct the dysbalance between hydrogen acceptors and macroergic systems thus providing a metabolic defense for the ischemic brain.

Animals↗

PubMed1979

Q factor analysis applied to describe attitudes toward dental care.

This study used a modified form of Q factor analysis to introduce students to methods to identify and describe patient and provider attitudes toward dental care. Factor analysis of questionnaire results and a person by person correlation matrix allowed students to compare their own attitudes with those of their patients, faculty, and significant people in their lives. Results indicate certain issues regarding dental care on which all subjects agree. Subjects grouped themselves along different factors according to the relative importance each issue had for them. By identifying these issues and groupings, students had a systematic description of their specific "dentist-patient relationship." By including clusters of people significant in their own lives, students became personally involved in the purpose, methods, and results of the analysis.

Attitude↗

PubMed1988

Cost and quality of psycho-pedagogic institutional care: the case of 56 establishments in the Swiss canton of Vaud.

We studied 56 boarding institutions caring for 834 children and adolescents with different kinds of difficulties or handicaps in the Swiss Canton of Vaud. In order to weigh the purely qualitative approach we performed two different statistical analyses: 1) a correlation matrix between all qualitative and quantitative variables with the daily individual cost of the institutional care. This cost has been calculated in a standard manner and independently of each institution's accounts. 2) a factor analysis of the collected data led us to the identification of different patterns of institutional functioning. This study stresses the importance of the staff/pupil coefficient, i.e. the richness of the pedago-therapeutic framing--the intervention of specialists such as special teachers, psychologists, and speech and/or motor therapists-, and more particularly the higher ratio of specialist help compared to pure educative staff. The severity of the cases, evaluated by independent specialist observers, was in direct relation to this factor independently of the kind of difficulty or handicap.

Adolescent↗

PubMed1988

[Rheologic and morphometric parameters of the microcirculation bed in the rabbit ear following local ischemia].

Microvessels of the rabbit ear chamber and blood samples drawn from the internal ear vein were studied after 30-min ischemia. Total microvascular bed area augmented by 16%, total microvascular bed length increased by 9% and mean microvascular diameter increased by 6.7%. One hour after the onset of ischemia it is only the diameter that remains augmented. In the control experimental series apparent viscosity of the blood flowing from the ischemic area did not correlate with the degree of vascularization, negative relation with vessel length (p = --0.461) and positive relation with the diameter (p = 0.799) being revealed. After ischemia only the viscosity-diameter relation remained significant (p = 0.466). The correlation matrix 10 X 10 which reflected the connection between other parameters characterizing specificity of blood supply regulation is given.

Animals↗

PubMedDate not supplied

Self-esteem, social support, and positive health practices.

The purpose of this study was to identify relationships among perceived social support, self-esteem, and positive health practices among adults living in a south-western metropolitan area. The sample (N = 98) of convenience was selected from an adult apartment complex and the variables were measured using three self-report questionnaires (Personal Resource Questionnaire, Coopersmith Self-Esteem Inventory, and Personal Life-style Activities Questionnaire). Initially, a positive association among the variables, self-esteem, social support, and life-style, was determined using a simple correlation matrix. To further explicate the relationships among the variables, a theoretical causal model was developed and tested. Using path analytic techniques, both the direct and the indirect effects of various independent variables on life-style were determined; 28% of the variance, p less than .0001, was accounted for by this model. The study suggests that both self-esteem and social support are positive indicators of life-style. Further, social support was found to exert influence indirectly through its direct effect on self-esteem.

Adolescent↗

PubMed1985

The cardiac patient and exercise: a sociobehavioral analysis.

Health beliefs (health motivation, perceptions of illness, perceptions of resusceptibility, efficacy of treatment, barriers to treatment, and cues to taking health-related action), HLOC, patient satisfaction, social support, and self-motivation were studied in a group of cardiac patients (N = 41; 39 men and two women) who initiated and completed a phase II outpatient cardiac exercise program. Twenty-three had MI and 18 had CABG. They ranged in age from 34 to 75 years with a mean age of 53 1/2 years. Regarding health beliefs, the only subscales not reflecting the tendency toward compliant behavior were general health motivation and cues to taking health-related action. Scores on the remaining measures revealed a tendency for subjects to be externally controlled, satisfied with the program and staff, recipients of social support, and self-motivated. Although it was anticipated that patients with MI would differ significantly from patients who had CABG regarding these measures, this was not found to be true. A correlation matrix revealed that the most remarkable relationships were those between perceptions of severity of illness and general health motivation; HLOC and general health motivation; perceptions of severity and resusceptibility; cues to taking health-related action and satisfaction with the program staff; and satisfaction with the program and the program staff. Interestingly, perceptions of resusceptibility were negatively related to social support and self-motivation.

Adult↗

PubMed1977

Comparative analysis of some anthropometric measurements.

The main objective of this work is to determine what anthropometric method to use under field conditions, given the kind of mainutrition to be detected. In the first part of the work some criteria and procedures are given by which to compare the field perfomance characteristics (i.e. transportability, facility of use, etc.), of the most commonly used instruments. Then we extrapolate these characteristics to the respective methods like weight for age, weight for height, height for age, etc. In the second part we present a correlation matrix among the various methods and analyze it in order to associate with each method a specific typology of malnutrition.

Age Factors↗

PubMed1983

[Radiocardiogram interpretation by estimating the average transit time of a tracer].

A new method for the interpretation of the radiocardiographic (RCG) data is proposed. As distinct from the widely used method developed by Donato et al. based on the exponential extrapolation of the terminal zones of the RCG peaks and the calculation of the mean time of the indicator general circulation in the body, this one is based on the approximation of both RCG peaks by gamma-image function, measurement of the indicator maximum level in the field of interest of the vena cava superior and calculation of the time indices that characterize the mean-transit time of radioactivity through the right cardiac regions and through the heart and lungs in general. On examination of practically healthy persons and 62 patients with ischemic heart disease 10 different RCG time indices were identified. The correlation matrix of the interrelationships of these indices and the matrix of the coefficients of respective regression equations were calculated. It has been established that the mean time of general circulation results in the distorted evaluation of myocardial pump function whereas time indices determined by the above method give a more adequate evaluation of the central hemodynamics.

Coronary Disease↗

PubMed1984

Curve fitting for repeated measurements made at irregular time-points.

In longitudinal studies of human populations, it is often not feasible to measure all subjects at the same time-points. This precludes the use of classical methods of curve fitting for repeated measurements. When the total interval of follow-up is short for all subjects in the study, an intraclass correlation matrix is assumed for the measurements on each subject. An estimation procedure based on iteratively reweighted least squares is described. The model is then generalized to incorporate covariables, with little modification in the estimation procedure. The proposed method is applied to data from a longitudinal study of bone mass in postmenopausal women.

Aged↗

PubMed1983

An approach to the study of attentional components in auditory tasks.

Some investigators have proposed a number of strategies or components of attention based on the analysis of the demands or requirements of certain laboratory tasks. The present investigation approached the analysis of auditory and visual attention from a different perspective. Volunteers (14 F, 27 M) from the health professions were given two widely-used auditory attentional tasks (remembering taped word lists, and shadowing, in monaural, binaural, and dichotic modes) and three visual tests (Stroop color-word tests, embedded figures, and anagrams) that appear to tap important aspects of attentional functioning; 18 indices of aspects of performance were taken from or derived from scores on these tests. Strong, significant r's emerged for a number of paired variables, suggesting that performance in these tasks share common elements. A principal factor analysis performed on the correlation matrix yielded a remarkably clean solution that uncovered four common sources for the variation observed in performance: Factor I identifies an aspect of attention tapped whenever distractions must be overcome; II is involved in continuously tracking or monitoring semantic aspects of connected material; III is an "executive" function that maintains or controls other aspects of attention; IV can be labeled breadth of attention, dealing with opposite aspects of the same underlying mechanism. These appear to be attentional components that underlie performance even in tasks that impose dissimilar demands or that have been interpreted as engaging different aspects of the attentional system. The factor analysis also provided some tentative answers for questions related to the comparability of different auditory tasks and of different aspects of performance for the same task.

Attention↗

PubMed1984

Determining disease activity in inflammatory bowel disease.

To provide a stronger relationship between clinical assessment of disease activity and laboratory measurements, we studied hemoglobin concentrations, sedimentation rates, and the serum levels of albumin and of seromucoids in 86 patients; first when seriously ill with either ulcerative colitis or Crohn's disease, and then again when they were well. Only albumin and seromucoids were separated clearly in the two states: hemoglobin and sedimentation rates showed significant overlap. Paired correlation tests between 10 laboratory variables in 149 patients with Crohn's disease of varying severity revealed a highly significant correlation between seromucoids and albumin (r = 0.71). Both variables correlated with six others, but at lower levels. Processing the correlation matrix by factor analysis suggested that the serum levels of albumin and seromucoid are indicators of the same effect--disease activity. A simple index using only hemoglobin, albumin, and seromucoid values, was derived from this analysis, positive values indicating health and negative ill health. Serum levels of albumin and seromucoids provide the essential data to determine disease activity at routine follow-up of inflammatory bowel disease or to indicate the success or failure of therapeutic regimens, overriding any arbitrary clinical assessment.

Adult↗

PubMedDate not supplied

[Effect of tranquilizers on the motivation components and the tactics of operator activities].

The effect of tranquilizers on the motivation components and tactics of operator's activities was investigated, using a model of discrete tracking of a moving object. The correlation-matrix method was applied to determine the region of no error correction. It was shown that specific changes in the tactics of operator's activities developing in response to tranquilizers and reduced motivation were identical. It appears probable that decreased motivation of failure avoidance forms the phenomenon of preparedness of risk taking and optimization of operator's activities when tranquilizers are used under psychological conflict conditions.

Adult↗

PubMedDate not supplied

A validation study: simulations as a measure of nurse practitioners' problem-solving skills.

A national sample of 79 masters- and certificate-prepared family and adult nurse practitioners completed six instruments designed to validate one type of clinical simulation, patient management problems (PMPs). The instruments were: a self-chart audit, self-evaluation rating scale, colleague evaluation rating scale, multiple-choice examination. PMP simulation, and demographic questionnaire. Use of a multitrait-multimethod correlation matrix, a multivariate analysis of covariance, and a stepwise multiple regression analysis provided modest evidence to support the claim that the PMP simulation is a valid measure of the construct clinical problem solving. In fact, a multiple-choice examination appeared to be an equal, if not superior, instrument.

Clinical Competence↗

PubMedDate not supplied

[Premature aging from the biological dynamic viewpoint].

Contrary to normal and harmonic aging, the multiple dimensional and mainly nonsynchronous proceedings of premature aging mostly include a pathological process. The phenomenon of aspectual premature aging is accentuated and its specific structure is elaborated. Within the scope of a multiple systemical biological correlation matrix, modern neurophysiological points of view discussed, which specially target the central nervous infra-structure.

Aged↗

PubMed1995

Effect of some environmental factors on Rhizobium and Bradyrhizobium strains.

Effects of different abiotic factors (acidity, salinity, nitrate and temperature) on growth rate of root-nodule bacteria (Rhizobium and Bradyrhizobium) strains were investigated in vitro. Strains isolated from Vicia faba L., Coronilla varia L. and Lupinus albus L. exhibited a large variation in tolerance of the above-mentioned factors. These bacteria should be screened under stimulated conditions for enhanced survival before selection to be used for commercial inoculant production. Linear correlation matrix data were useful to find the appropriate concentrations for the selection of the tolerant strains.

Environment↗

PubMed1995

Worldwide analysis of genetic and linguistic relationships of human populations.

In this study we relate language differences on a global scale with genetic distances for the same populations. The analysis is carried out on more populations (130) but fewer genetic systems (11) than earlier studies. We constructed an overall genetic distance matrix that allowed for missing values. A separate genetic distance matrix was also computed for each genetic system, and matching matrices of linguistic and geographic distances were associated with each genetic distance matrix, because the number of populations used differed among the genetic systems studied. Significant matrix correlations between language and genetics were found for both overall genetic distances and a substantial number of genetic systems, even when the effects of geographic distances were held constant. This demonstrates a significant correspondence between genetics and language on a global scale. Genetic matrices were correlated with two different linguistic distance matrices: one with higher (supraphyletic) taxonomic structure, in which among other features sub-Saharan Africans separate from non-Africans in the basal split and the Eurasiatic superphylum is postulated; and one without such structure. The correlations yield no genetic evidence to support the proposed higher linguistic structure. UPGMA and neighbor-joining trees were constructed for linguistic and genetic data. The proposed African split pattern is not supported by these data. Both types of trees indicate a pattern of grouping of east Asians, Arctic populations, and Australian natives separating from Caucasoid and African populations.

Ethnicity↗