Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “canonical correlation analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1998

Influence of fitness on susceptibility to noise-induced temporary threshold shift.

PURPOSE: Two earlier reports indicated that cardiovascular fitness attenuates susceptibility to noise-induced temporary threshold shift (TTS) in hearing sensitivity; however, other parameters of fitness also may be related to this phenomenon. This study investigated the association of three different physical fitness indicators on TTS. METHODS: Maximal aerobic power (VO2max), body composition. and recent activity history were determined in 33 normal-hearing females of various fitness levels. Audiometric thresholds were obtained at 2000, 3000, 4000, and 6000 Hz before and immediately after 10 min of exposure to 108-dB SPL narrow-band noise centered at 2000 Hz. RESULTS: All postnoise measurements were significantly less than prenoise measurements (P < 0.0001) with the greatest TTS occurring at 3000 Hz. Similarly, the strongest Pearson-product correlations for VO2max, % fat, and recent activity history with TTS occurred at 3000 Hz (r = -0.68, 0.60, -0.59, respectively; P < 0.05). Canonical correlation analysis indicated a moderate correlation between physical fitness and TTS (Rc = 0.71: P < 0.01). Individually, VO2max, % fat, and recent activity history had correlations of -0.70, 0.62, and -0.63, respectively, to the TTS canonical variable. CONCLUSIONS: From these results, we concluded that there is a moderate association of physical fitness and diminished temporary hearing loss experienced after noise exposure.

Adolescent↗
PubMed1986

A sociodemographic analysis of preventive dental behavior among white American families.

Data collected from a national family dental survey were used to study the relationships between the sociodemographic characteristics and the preventive dental behavior of wives, husbands, and children. A canonical correlational analysis showed that preventive dental behavior of family members including toothbrushing, flossing, and preventive dental visits, significantly correlated with sociodemographic characteristics (level of education, income, occupation, population density, age, family size, and presence of children). The relationships studied accounted for 11-15% of the variance in the preventive dental behavior of family members. However, the patterns of correlation for different family members varied. The extent of the effects of various sociodemographic variables on preventive dental behavior were not uniform and the degrees of responsiveness of toothbrushing, flossing, and dental visits to the influence of sociodemographic characteristics were also different. The results of the study are compared with those of previous studies. The implications of the findings are discussed.

Adolescent↗
PubMedDate not supplied

Variable selection and specification of robust QSAR models from multicollinear data: arylpiperazinyl derivatives with affinity and selectivity for alpha2-adrenoceptors.

Two QSAR models have been identified that predict the affinity and selectivity of arylpiperazinyl derivatives for alpha1 and alpha2 adrenoceptors (ARs). The models have been specified and validated using 108 compounds whose structures and inhibition constants (Ki) are available in the literature [Barbaro et al., J. Med. Chem., 44 (2001) 2118; Betti et al., J. Med. Chem., 45 (2002) 3603; Barbaro et al., Bioorg. Med. Chem., 10 (2002) 361; Betti et al., J. Med. Chem., 46 (2003) 3555]. One hundred and forty-seven predictors have been calculated using the Cerius 2 software available from Accelrys. This set of variables exhibited redundancy and severe multicollinearity, which had to be identified and removed as appropriate in order to obtain robust regression models free of inflated errors for the beta estimates - so-called bouncing betas. Those predictors that contained information relevant to the alpha2 response were identified on the basis of their pairwise linear correlations with affinity (-log Ki) for alpha2 adrenoceptors; the remaining variables were discarded. Subsequent variable selection made use of Factor Analysis (FA) and Unsupervised Variable Selection (UzFS). The data was divided into test and training sets using cluster analysis. These two sets were characterised by similar and consistent distributions of compounds in a high dimensional, but relevant predictor space. Multiple regression was then used to determine a subset of predictors from which to determine QSAR models for affinity to alpha2-ARs. Two multivariate procedures, Continuum Regression (the Portsmouth formulation) and Canonical Correlation Analysis (CCA), have been used to specify models for affinity and selectivity, respectively. Reasonable predictions were obtained using these in silico screening tools.

Models, Molecular↗
PubMed1975

Recalled parental behavior and objective personality measures: a canonical analysis.

Information about an individual's past relationships with his parents is an important component in psychological assessment procedures. To systematically connect these relationships and personality, two groups of college students completed an objective inventory designed to assess parental child rearing behaviors. Canonical correlational analysis was employed to relate these measures to the CPI and MMPI. A recalled parental behavior component described as Acceptance vs. Hostile Detachment/Involvement emerged as being highly related to aspects of both personality inventories, with greater recalled acceptance (and lesser recalled hostility) being associated with the more positive aspects of personality. Additional findings are enumerated.

Adolescent↗
PubMed2002

Signatures of large-scale and local climates on the demography of white-tailed ptarmigan in Rocky Mountain National Park, Colorado, USA.

Global climate change may impact wildlife populations by affecting local weather patterns, which, in turn, can impact a variety of ecological processes. However, it is not clear that local variations in ecological processes can be explained by large-scale patterns of climate. The North Atlantic oscillation (NAO) is a large-scale climate phenomenon that has been shown to influence the population dynamics of some animals. Although effects of the NAO on vertebrate population dynamics have been studied, it remains uncertain whether it broadly predicts the impact of weather on species. We examined the ability of local weather data and the NAO to explain the annual variation in population dynamics of white-tailed ptarmigan ( Lagopus leucurus) in Rocky Mountain National Park, USA. We performed canonical correlation analysis on the demographic subspace of ptarmigan and local-climate subspace defined by the empirical orthogonal function (EOF) using data from 1975 to 1999. We found that two subspaces were significantly correlated on the first canonical variable. The Pearson correlation coefficient of the first EOF values of the demographic and local-climate subspaces was significant. The population density and the first EOF of local-climate subspace influenced the ptarmigan population with 1-year lags in the Gompertz model. However, the NAO index was neither related to the first two EOF of local-climate subspace nor to the first EOF of the demographic subspace of ptarmigan. Moreover, the NAO index was not a significant term in the Gompertz model for the ptarmigan population. Therefore, local climate had stronger signature on the demography of ptarmigan than did a large-scale index, i.e., the NAO index. We conclude that local responses of wildlife populations to changing climate may not be adequately explained by models that project large-scale climatic patterns.

Animals↗
PubMed2006

No simple answers for ecological immunology: relationships among immune indices at the individual level break down at the species level in waterfowl.

Understanding immune function in the context of other life-history traits is crucial to understand the evolution of life histories, at both the individual and species levels. As the interest in assessing immune function for these comparative purposes grows, an important question remains unanswered: can immune function be broadly characterized using one or two simple measures? Often, interpretation of individual assays is ambiguous and relationships among different measures of immune function remain poorly understood. Thus, we employed five protocols to measure 13 variables of immune function in ten species of waterfowl (Anseriformes). All assays were based on a single blood sample subdivided into leukocyte (blood smear) and plasma (frozen until analysis) components. All assays were run using samples from every individual, and a nested analysis was used to partition variation/covariation at the levels of species and individuals within species. We detected positive correlations between functionally related measures of immunity within species, but these were absent from comparisons between species. A canonical correlation analysis revealed no significant relationships between the plasma and leukocyte assays at the levels of both individual and species, suggesting that these measures of immunity are neither competitive nor synergistic. We conclude that one measure of each assay type may be required to maximally characterize immune function in studies of a single species, while the same is not true in studies among species.

Animals↗
PubMed2006

Relations of the morphological characteristic latent structure and body posture indicators in children aged seven to nine years.

With the aim of determining the connection between the indicators of body posture and latent structure of morphological variables in children aged 7 and 8 years, first and second grade of primary school, a set of 17 morphological measures and 12 body posture indicators were longitudinally applied to a sample of 110 boys and 114 girls. The latent structure of morphological variables in both sexes was defined by three factors but at a different order of significance: in boys, the order was longitudinal dimensionality, voluminosity, mass and subcutaneous fat tissue and transverse dimensionality, whereas in girls the order was voluminosity, mass and subcutaneous fat tissue, longitudinal dimensionality and transverse dimensionality. The latent structure of torax body posture indicator was defined by two factors, the status of body posture of the rear part of the thorax, and status of the body posture of the front part of the thorax. The results obtained by canonical correlation analysis between predictive variables, morphological latent structure and criterion variables, latent structure of thorax body posture indicators with two posture indicators of the chest and one of the foot status, showed two important pairs of canonical roots on each measurement, suggesting a significant association between these two sets of parameters.

Body Weights and Measures↗
PubMed1990

Caregiver needs and patterns of social support.

Levels of caregiver need were used to predict four patterns of continuity and change in social support over a one-year interval among 376 adults caring for a family member with Alzheimer's disease. Canonical correlation analysis was used to identify predictors of each support pattern from selected caregiver characteristics and needs (i.e., demographics, financial resources, physical and mental health, social and recreational activities, and aspects of the caregiving situation). Three significant canonical variates emerged for each type of support, instrumental and perceived adequacy of support, correctly classifying more than half of the caregiver sample. Results suggest that caregiver need does not necessarily elicit support. Needs do, however, predict several patterns of social support, the most common of which is characterized by stability (high or low support). Depending on type of support (instrumental or perceived adequacy), different configurations of predictors emerge.

Adult↗
PubMed2005

The Impact of Patient Aggression on Carers Scale: instrument derivation and psychometric testing.

Patient aggression towards carers constitutes a problem for patients and carers alike. Patients' aggressive behaviour often leads to adverse consequences for carers, especially nurses. Various extensive instruments have been developed to measure such adverse effects on carers. The 'Impact of Patient Aggression on Carers Scale' (IMPACS) is a short instrument intended for use in monitoring negative consequences of such incidents. The items of the IMPACS were derived basically from a review of the literature on negative effects of patient aggression on nurses. The IMPACS was administered to a convenience sample of nurses working on 14 psychiatric acute admission wards in the German speaking part of Switzerland. Factor analysis led to the exclusion of three of the original items and to an interpretable three-factor solution with all factors demonstrating eigen values higher than 1. The factors demonstrate moderate to good internal consistency. Canonical correlation analysis using the dimensions of the Maslach Burnout Inventory (MBI) produced a correlation coefficient of 0.457, thus demonstrating external reliability. In spite of some caveats such as possible response bias and the necessity of the investigation of the test-retest stability of the scale this study suggests that the IMPACS is a good measure of adverse effects and thus merits further development.

Adult↗
PubMedDate not supplied

Body circumferences as alternatives to skinfold measures of body fat distribution in children.

The ratios of circumferences (waist/hip, waist/thigh) have been proposed in lieu of skinfold measurements for studies of obesity and body fat distribution in adults. The skinfold method has been used successfully in children to study the growth and development of patterns of body fat distribution, but circumferences have not. We studied the relationship between these two methodologies as indicators of body fat and its anatomical distribution among 365 normal children aged 6-11 years, using canonical correlation analysis. With this method, weighted vectors of four body circumferences on the one hand and five skinfolds on the other are formed in such a way that the correlation between the two sets of variables is maximized. Weights (regression coefficients) are assigned each variable and their strength and sign help us to select the best combination of circumferences which describe a component of centralised obesity. A first canonical correlation was substantial in both boys and girls (0.84) and was independent of age. It appeared to relate to fatness level. A second canonical correlation was low (0.34 in boys, 0.35 in girls) (p less than 0.01). It too was age independent and in both sexes it reflected differences between fat on the trunk and on the lower extremity, and was thus a component of centralised fat distribution. The simple waist/thigh ratio correlated better with this canonical variable (0.67-0.88) than the more commonly used waist/hip ratio (0.45-0.79). The 'best' index of centralised fat in children is therefore, the waist/thigh circumference ratio, the same one that has been suggested for adults.

Adipose Tissue↗
PubMed2005

Combined 99mTc-ECD SPECT and neuropsychological studies in MCI for the assessment of conversion to AD.

Identifying pre-clinical Alzheimer's disease (AD) in subjects with mild cognitive impairment (MCI) is a major issue in clinical diagnosis. Establishing a combination of predictive markers from different fields of research might help in increasing the diagnostic accuracy. Aim of this study was to evaluate the potential role of 99mTc-ECD single photon emission computed tomography (SPECT) and memory scores in predicting conversion to AD in MCI subjects. Thirty-one MCI subjects underwent a clinical and neuropsychological examination, and a regional cerebral blood flow (rCBF) SPECT scan at baseline. Subjects had been followed periodically through 2 years in order to monitor the progression of cognitive symptoms. Canonical variate analysis of principal components was able to separate all subjects who converted to AD from those who remained stable, the former being characterized by a specific hypometabolic pattern, involving the parietal and temporal lobes, precuneus, and posterior cingulate cortex. Canonical correlation analysis of combined baseline memory deficits and rCBF SPECT images identified pre-clinical AD with a sensitivity and specificity of 77.8%. The pattern of hypoperfusion 99mTc-ECD SPECT and the severity of memory deficits predict the risk of progression to probable AD dementia in MCI subjects.

Alzheimer Disease↗
PubMed2006

Fast nosologic imaging of the brain.

Magnetic resonance spectroscopic imaging (MRSI) provides information about the spatial metabolic heterogeneity of an organ in the human body. In this way, MRSI can be used to detect tissue regions with abnormal metabolism, e.g. tumor tissue. The main drawback of MRSI in clinical practice is that the analysis of the data requires a lot of expertise from the radiologists. In this article, we present an automatic method that assigns each voxel of a spectroscopic image of the brain to a histopathological class. The method is based on Canonical Correlation Analysis (CCA), which has recently been shown to be a robust technique for tissue typing. In CCA, the spectral as well as the spatial information about the voxel is used to assign it to a class. This has advantages over other methods that only use spectral information since histopathological classes are normally covering neighbouring voxels. In this paper, a new CCA-based method is introduced in which MRSI and MR imaging information is integrated. The performance of tissue typing is compared for CCA applied to the whole MR spectra and to sets of features obtained from the spectra. Tests on simulated and in vivo MRSI data show that the new method is very accurate in terms of classification and segmentation. The results also show the advantage of combining spectroscopic and imaging data.

Algorithms↗
PubMed2000

Five-factor model of schizophrenic psychopathology: how valid is it?

Aim of the study was to examine the consistency of the five-factor model of schizophrenic symptoms, assess its validity and evaluate its dimensional factor structure using confirmatory factor (CFA) analysis. A sample of 258 randomly assigned DSM-III R patients with schizophrenic disorders were studied by means of the structured clinical interview for the Greek validated Positive and Negative Syndrome Scale (PANSS) and were rated on its 30 items. Patients' scores were subjected to principal component analysis (PCA) with varimax rotation. Internal consistency for each of the components was determined by the use of Cronbach's alpha. External validity of the model derived was investigated by searching for possible relationships between the components and sociodemographic characteristics with the aid of canonical correlation analysis. Confirmatory factor analysis (CFA) was also performed. Using the scree plot criterion PCA revealed a five-factor model. These factors were interpreted as representing--in a decreasing order of relative importance--the following dimensions of schizophrenic psychopathology: negative, excitement, depression, positive and cognitive impairment. The model was comparable with six previous factor analytic studies. Internal consistency was quite satisfactory whereas external validity was found to be not so powerful. CFA did not show that the proposed model yields an adequate factor structure.

Adult↗
PubMed1999

The analysis of the data for two-way contingency tables.

One of the best ways, if not the best way, to analyze data displayed in a two-way contingency table is to use a method originally due to Williams (1952) and later embellished upon by Guttman (1971) and others. This method applies the principles of canonical correlation analysis to contingency table data and obviates the need for the a priori specification of scale values for the two variables whose relationship is explored. In this article the method is described and compared with other approaches, and several examples of its application are provided.

Humans↗
PubMed1984

Relationships between language skills as assessed by the Halstead-Reitan battery and the Luria-Nebraska language-related factor scales in a nonaphasic patient population.

The study involved a comparison between language tests derived from the Halstead-Reitan and Luria-Nebraska neuropsychological test batteries. Language-related measures from each battery were entered into a factor analysis based on a sample of 150 nonaphasic neuropsychiatric patients. Five factors were extracted and were named Academic Achievement, Basic Skills, Verbal Intelligence, Auditory Discrimination, and Comprehension of Syntactical Relations. Measures from both the Halstead-Reitan and Luria-Nebraska loaded on most of these factors. A canonical correlation analysis revealed a strong relationship between the Halstead-Reitan and Luria-Nebraska measures. However, it was noted that interpretation of this relationship must be qualified by the association found between the measures used and educational achievement.

Adult↗
PubMed2006

Relationships among epipelic diatom taxa, bacterial abundances and water quality in a highly polluted stream catchment, bursa -- Turkey.

Nilüfer Stream is an important water source in the industrial and metropolitan city of Bursa, Turkey. The stream catchment has been influenced by high human impact. The downstream receives sewage water from households and industry, whereas the headwater of the stream has a source of high-quality drinkable water. In this paper, abundances of epipelic diatom taxa, faecal coliforms (FC), total coliforms (TC) and total bacteria (TB) were studied in relation to measured environmental variables (T, pH, DO, BOD(5), EC, TDS) for the period July 1997 to June 1998 at six stations in the heavily polluted Nilüfer Stream catchment. It is observed that the physicochemical variables and bacterial abundances varied seasonally at all stations, and the level of pollution reached at its highest point in the summer. The results of Kruskal-Wallis and one-way ANOVA indicated that DO gradually decreased, whereas BOD(5), EC, TDS, TB, FC and TC gradually increased from upstream to downstream. The ordination method of Principal Component Analysis (PCA) was carried out for both biologic and physicochemical variables, and the results were supported by the former statistical procedures. The frequency of occurrence of dominant diatoms was examined in relation to the spatial variations in chemical constituents. Both diatoms and bacteria showed strong correlations with the measured physicochemical variables. In Canonical Correlation Analysis (CANCORR) measures of bacterial abundances also displayed strong correlations with abundances of 11 diatom taxa. The results showed that the stream catchment is polluted gradually from upstream to downstream. In addition, pollution load in the stream catchment has been gradually increased, compared with recent years. Urbanisation and industrialisation of the city have affected increasing pollution in Nilüfer Stream. The results also indicated that diatoms are not affected by environmental variables such as bacteria. Bacteria are more sensitive to organic pollution, while diatoms are indicators of different environmental conditions.

Analysis of Variance↗
PubMed2003

Personality and depressive symptoms: a multi-dimensional analysis.

BACKGROUND: The relationship of temperamental aspects of personality to symptoms of depression in a community-based sample of 804 individuals was examined using a multi-dimensional approach to account for heterogeneity in symptom patterns. METHOD: The Temperament and Character Inventory (TCI) was used to assess personality and the Center for Epidemiologic Studies Depression scale (CES-D) was used to measure depressive symptoms. Canonical correlation analysis was used to relate CES-D item combinations to temperament traits in multiple dimensions. The relationships between temperament and various conditions correlated with depression were examined using logistic regression. RESULTS: Temperamental aspects of personality are related not only to total CES-D score, but also to the patterns of CES-D items endorsed by subjects. High Harm Avoidance is related to total CES-D score; high Reward Dependence combined with high Persistence is associated with restless sleep and subjective symptoms; high Reward Dependence combined with low Persistence is negatively associated with appetite loss and low energy; high Novelty Seeking is related to maintenance of positive affect and inability to concentrate. High Novelty Seeking is also associated with past suicide attempts, after adjusting for total CES-D score. LIMITATIONS: Cross-sectional data prevent analysis of causation; the severest cases of clinical depression may not be represented in a general population sample. Depressive symptoms are self-reported. CONCLUSION: Substantial differences in level of symptoms and in symptom patterns exist among individuals in a continuum of depressed states and those differences are partially explained by temperament traits.

Adolescent↗
PubMed2004

[Canonical correlation and redundancy analysis on the indices of abdominal ultrasonography of schistosomiasis japonica].

OBJECTIVE: To explore the correlation of the ultrasound indices of liver and spleen in schistosomiasis japonica and with infection frequency, infection time and EPG. METHODS: The canonical correlation was applied to analyze the correlation of the hepatosplenic ultrasound indices in schistosomiasis japonica, and the correlation of the ultrasound indices with infection frequency, infection time and EPG. The proportions of variation related to each other in liver and spleen were analyzed by the redundancy analysis. RESULTS: The correlation coefficients of the first pair correlation canonical variable were 0.7842, 0.5483 and 0.5800, 0.4220, respectively, in males and females without infection, males and females with infection history (P<0.01). The correlation coefficients of the first pair correlation canonical variable were 0.6063, 0.5215 and 0.6595, 0.3849, respectively, in male negatives and female negatives, male positives and female positives (P<0.01). In groups of males and females without infection, the variations of liver ultrasound indices related with the variation of spleen ultrasound indices were 43.5% and 17.5% respectively, and in groups infection history, they were 22.1% and 11.4% respectively. In male and female negative groups, the variations of liver ultrasound indices related with the variation of spleen ultrasound indices were 26.8% and 16.8% respectively, and in positive groups, they were 27.6% and 10.7% respectively. The infection frequency, infection time and EPG in the stool-positive groups were not significantly related with the canonical variables of liver and spleen ultrasound indices (P>0.05). CONCLUSION: There is a significant canonical correlation between the liver and spleen ultrasound indices in schistosomiasis japonica, especially in males. In groups with infection history, the infection frequency, infection time and EPG of those stool-positives are not relevant to the canonical variables of liver and spleen ultrasound indices.

Adolescent↗