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PubMed1994

[Assessment of the activities of daily living age in elderly women].

The purpose of this study was to assess activities of daily living age in elderly. The subjects were 253 Korean elderly women, aged 60 to 91 years, all of whom were participants in an elderly school program managed by the Seoul City. Activities necessary for independence in daily living must be selected from various components. First of all, a questionnaire was administered to clarify the areas of activities of daily living in the elderly. Factor analysis with Normal Varimax criterion was applied to the data, and the factors extracted were interpreted as locomotion of whole body, manipulation of upper limb, manipulation of finger, and change of posture. Secondly, twenty-four performance tests related to the activities of daily living were selected. Principal component analysis was applied to the 24 x 24 correlation matrix, and first principal component was interpreted as total activities of daily living because of significantly heavy loadings with all variables. Principal component score decreased significantly with advancing age (r = -0.578). Multiple regression analysis revealed that out of the 24 variables examined, 5 were suitable for the assessment of the activities of daily living. The equation developed to determine the activities of daily living age (ADLA) was ADLA = 6.28 ADLS + 72.21 + Z, ADLS = -0.039x1 + 0.051x2 + 0.048x3 + 0.015x4 + 0.012x5 - 2.76, Z = 0.44 Age-31.45; where x1 = walking around two chairs in a figure 8, x2 = moving beans from one container to another using pincers, x3 = grip strength, x4 = raising the arms above the head while holding a bar, and x5 = balancing on one leg with eyes open.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed2005

Single-crystal studies of peptide prolyl and glycyl 15N shielding tensors.

15N shielding tensors were determined for the central peptide groups in GGV, AGG, and APG by single-crystal NMR. We find that the angle between the downfield component (delta11) and the N-H or the N-C(delta) (pro) bonds is in the range of 20-23 degrees and in accord with previous solid-state NMR measurements. However, AGG, unlike APG or GGV, has a distorted peptide plane, and delta11 lies approximately in the plane of N, C(alpha), and H rather than in the peptide plane defined by heavy atoms. Accurate orientations of delta22 and delta33 were determined, and the usual assumption that delta22 is along the peptide normal was found only in APG which has a highly nonaxial tensor. More generally, delta22 and delta33 are rotated about the delta11 axis (36 degrees in GGV). These results are compared with DFT calculations to gain a structural understanding of the effects of intermolecular interactions on shielding tensor principal components and orientations. Trimeric clusters containing H-bonded neighbors predict the orientations of the principal components within 2-3 degrees, but calculated principal components are less quantitative. Possible reasons for this disagreement are explored.

Crystallization↗
PubMed2004

[RAPD fingerprinting of common bream Abramis brama L., roach Rutilus rutilus L., and their F1 hybrids].

The polymerase chain reaction with arbitrary primers (RAPD-PCR) was used to study and to evaluate the genetic variation in the hybrid progeny of two Cyprinidae species, common bream Abramis brama and roach Rutilus rutilus. Genetic polymorphism was studied in 20 fishes (young of the current year) obtained in four individual crosses: R. rutilus x R. rutilus (RR), A. brama x A. brama (AA), R. rutilus x A. brama (RA), and A. brama x R. rutilus (AR). Amplification spectra obtained with eight primers contained 288 fragments, 97.6% of which proved to be polymorphic. The proportion of polymorphic fragments was 75.0% in the RR progeny, 58.1% in the AA progeny, 84.9% in the AR progeny, and 77.8% in the RA progeny. Classification analysis in the space of principal components was performed with the first four components, which together accounted for 64% of the total variance of the character under study. The individual contributions of components I, II, III, and IV were 26.8, 16.8, 11.5, and 8.9%, respectively. Fishes of the two pure species and the hybrid progeny (direct and reverse hybrids together) were clearly differentiated in the space of principal components I and II. The best differentiation of the four samples (RR, AA, RA, and AR) was observed in the space of principal components II and IV. Possible causes of high genetic variation in interspecific hybrids are discussed.

Animals↗
PubMed1990

Kinetics and block of dopamine uptake in synaptosomes from rat caudate nucleus.

The dopamine (DA) uptake system in mammalian nerve terminals was studied by measuring the unidirectional influx of tritiated DA into synaptosomes prepared from rat caudate nucleus. Two distinct time-dependent components of DA uptake were observed. The principal component was saturable with respect to DA concentration, required both external Na and Cl, and was competitively blocked by micromolar concentrations of the psychotropic agents cocaine, benztropine, nomifensine, amphetamine, and methamphetamine. This principal component of uptake has the properties expected for a carrier-mediated transport system. The second component, which accounted for about 10-30% of the DA uptake at 2 microM DA, was not saturable, and was independent of external Na, Cl, and blockers of the carrier-mediated system. The saturable, Na-dependent component had an apparent Km(DA) of about 0.5 microM. The dependence of DA uptake on external Na was sigmoid [Hill coefficient = 2; Ka(Na) = 45 mM] whereas the dependence on Cl was best described by a rectangular hyperbola [Ka(Cl) = 15 mM]. Depolarizing conditions (elevated external K) reduced the rate of DA influx. The data are consistent with a carrier-mediated DA transport mechanism in which each DA molecule entering the nerve terminal via the carrier is accompanied by two or more Na ions and one Cl ion in a rheogenic process carrying one or more net positive charges into the cell. Net, concentrative accumulation of DA inside nerve terminals may be accomplished by utilizing the Na electrochemical gradient to drive DA against its electrochemical gradient via this carrier system.

Animals↗
PubMed2000

Factors influencing the variability of SO2 concentrations in Istanbul.

The correlation between sulfur dioxide (SO2) concentrations measured at the European and Asian sides of Istanbul and meteorological parameters is investigated using principal component analysis (PCA) and multiple regression analysis techniques. Several meteorological parameters are selected to represent the atmospheric conditions during two winter periods: 1993-1994 and 1994-1995. Six principal components are found to explain the majority of the observed meteorological variability. Surface pressure, 850-mb temperature, and surface zonal (east-west) and meridional (north-south) winds show high loadings on separate factors identified by PCA. We seek dominant meteorological parameters that control the SO2 levels at each monitoring station. Several multiple regression analysis models are fitted to the data from each monitoring station using six principal components and previous-day SO2 concentrations as independent variables. Results suggest that the most important parameters, highly correlated with SO2 concentrations in the Istanbul metropolitan area, are atmospheric pressure and surface zonal and meridional winds. These components have more influence on the determination of the air pollution levels at the Asian side than at the European side.

Air Pollutants↗
PubMedDate not supplied

Logistic regression when binary predictor variables are highly correlated.

Standard logistic regression can produce estimates having large mean square error when predictor variables are multicollinear. Ridge regression and principal components regression can reduce the impact of multicollinearity in ordinary least squares regression. Generalizations of these, applicable in the logistic regression framework, are alternatives to standard logistic regression. It is shown that estimates obtained via ridge and principal components logistic regression can have smaller mean square error than estimates obtained through standard logistic regression. Recommendations for choosing among standard, ridge and principal components logistic regression are developed. Published in 2001 by John Wiley & Sons, Ltd.

Computer Simulation↗
PubMed1992

Fat distribution and blood lipids in a sample of healthy elderly people.

The cross-sectional sample consisted of data for 41 white men and 63 white women, 67-92 years of age who were healthy volunteer participants in the Aging Process Study at the University of New Mexico School of Medicine in Albuquerque, New Mexico. The variables consisted of anthropometric measures of body fatness, blood lipids and blood pressures. Correlations were computed between principal component scores, ratios of body circumferences, W/S2, blood lipid values and blood pressures for each sex. In the men, the significant correlations were of the abdomen/hip and abdomen/thigh ratios with W/S2, and the principal component scores with HDL cholesterol, triglyceride and systolic blood pressure. In the women, the abdomen/hip ratio had a low negative correlation with HDL cholesterol but a low positive correlation with triglyceride levels. The principal component scores also had low correlations with blood pressure and triglycerides. Multiple regressions were used to determine further associations between risk factors and fat distribution indices. In the men, the relationships of age and levels of body fatness with HDL cholesterol were much stronger and more complex than those with triglyceride or systolic blood pressure. In the women, only HDL cholesterol and triglyceride were associated with abdomen/hip ratio after removing the effects of overall fatness. The present findings indicate that a large abdominal circumference, implying a correspondingly large internal adipose tissue deposit, produces negative health alterations in blood lipid levels in this sample of elderly individuals. In younger adults, these changes are considered to increase the risk for cardiovascular disease.

Adipose Tissue↗
PubMed1997

Direction selectivity of synaptic potentials in simple cells of the cat visual cortex.

Direction selectivity of synaptic potentials in simple cells of the cat visual cortex. J. Neurophysiol. 78: 2772-2789, 1997. The direction selectivity of simple cells in the visual cortex is generated at least in part by nonlinear mechanisms. If a neuron were spatially linear, its responses to moving stimuli could be predicted accurately from linear combinations of its responses to stationary stimuli presented at different positions within the receptive field. In extracellular recordings, this has not been found to be the case. Although the extracellular experiments demonstrate the presence of a nonlinearity, the cellular process underlying the nonlinearity, whether an early synaptic mechanism such as a shunting inhibition or simply the spike threshold at the output, is not known. To differentiate between these possibilities, we have recorded intracellularly from simple cells of the intact cat with the whole cell patch technique. A linear model of direction selectivity was used to analyze the synaptic potentials evoked by stationary sine-wave gratings. The model predicted the responses of cells to moving gratings with considerable accuracy. The degree of direction selectivity and the time course of the responses to moving gratings were both well matched by the model. The direction selectivity of the synaptic potentials was considerably smaller than that of the intracellularly recorded action potential, indicating that a nonlinear mechanism such as threshold enhances the direction selectivity of the cell's output over that of its synaptic inputs. At the input stage, however, the cells apparently sum their synaptic inputs in a highly linear fashion. A more constrained test of linearity of synaptic summation based on principal component analysis was applied to the responses of direction-selective cells to stationary gratings. The analysis confirms that the summation in these cells is highly linear. The principal component analysis is consistent with a model in which direction selectivity in cortical simple cells is generated by only two subunits, each with a different receptive-field position and response time course. The response time course for each of the two subunits is derived for four analyzed cells. Each derived subunit is linear in spatial summation, suggesting that the neurons that comprise each subunit are either geniculate X-cells or receive their primary synaptic input from X-cells. The amplitude of the response of each subunit is linearly related to the contrast of the stimulus. The subunits are nonlinear in the time domain, however: the response to a stationary stimulus whose contrast is modulated sinusoidally in time is nonsinusoidal. The principal component analysis does not exclude models of direction selectivity based on more than two subunits, but such higher-order models would have to include the constraint that the extra subunits form a smooth continuum of interpolation between the properties derived from the two subunit solution.

Animals↗
PubMed1984

[Balanced hereditary polymorphism and the mortality from cardiovascular diseases in the populations of 17 countries of Europe. II. A component analysis].

Based on the factor analysis (the method of principal components with a varimax rotation of axes), a study was performed on the component structure of interpopulational variations in frequencies of the 50 phenotypes and genes of six polymorphic human systems (ABO, MNSs, Rh, Hp, Gm, HLA). The genetic differences of populations have been found to be related to a small number of independent factors; 7 principal components have extracted 79% of dispersion from the primary data. Five of these components are coupled with mortality from the cardiovascular diseases. The component structure of mortality has specificity in relation to localization of pathological process, age and sex.

Adult↗
PubMedDate not supplied

Class definition and mixture class definition by means of construction of convex hull boundaries: application to analysis for animal fat adulteration.

A visual classification technique based on the construction of convex hull boundaries in combination with a principal component analysis is described. This combined technique was evaluated in the situation in which a distinction has to be made between 2 pure animal fat classes and the corresponding mixture class. In the first instance, a principal component analysis is carried out to ensure the 2-dimensional and thus visual aspect of the technique. Convex hulls are then constructed in the 2-dimensional principal component plane to delimit the boundaries of the different classes to be defined. The effectiveness of the constructed hull boundaries in the definition of class-membership was investigated by means of the classification of different simulated test samples. The results show that, at least for the tested applications, the technique is valid, although some false positive classifications occur. The detection of outliers especially seemed to pose problems. Therefore, some propositions are made of how to refine the developed hull technique to enhance the classification results.

Animals↗
PubMed2005

Morphometric analysis of lumbar vertebrae in extinct Malagasy strepsirrhines.

Previous research on subfossil lemurs has revealed much about the positional behavior of these extinct strepsirrhines, but a thorough quantitative analysis of their vertebral form and function has not been performed. In this study, 156 lumbar vertebrae of Pachylemur, Archaeolemur, Megaladapis, Mesopropithecus, Babakotia, and Palaeopropithecus (11 species in all) were compared to those of 26 species of extant strepsirrhines and haplorhines. Lumbar shape was compared among species, using a principal components analysis (PCA) in conjunction with selected vertebral indices. The first principal component revealed strong separation between Palaeopropithecus at one extreme, and Archaeolemur/Pachylemur at the other, with Babakotia, Mesopropithecus, and Megaladapis in an intermediate position. Palaeopropithecus has markedly shorter spinous processes and wider laminae than do the other subfossil taxa, consistent with sloth-like, inverted suspensory postures. The moderately reduced lumbar spinous processes of Babakotia, Mesopropithecus, and Megaladapis are convergent with those of lorisids and Pongo, reflecting antipronogrady, but a less specialized adaptation than that of Palaeopropithecus. Archaeolemur and Pachylemur share relatively elongated spinous processes, in conjunction with other features (e.g., transverse process orientation and relatively short vertebral bodies) indicative of pronograde, quadrupedal locomotion characterized by reduced agility. All subfossil taxa exhibit adaptations emphasizing lumbar spinal stability (e.g., relatively short vertebral bodies, and transverse processes that are not oriented ventrally); we believe this probably reflects convergent mechanical demands connected to large body size, irrespective of specific locomotor mode. Reconstructions of positional behavior in subfossil lemurs based on lumbar vertebrae are largely consistent with those based on other aspects of the postcrania.

Animals↗
PubMed1994

Structural aspects of face recognition and the other-race effect.

The other-race effect was examined in a series of experiments and simulations that looked at the relationships among observer ratings of typicality, familiarity, attractiveness, memorability, and the performance variables of d' and criterion. Experiment 1 replicated the other-race effect with our Caucasian and Japanese stimuli for both Caucasian and Asian observers. In Experiment 2, we collected ratings from Caucasian observers on the faces used in the recognition task. A Varimax-rotated principal components analysis on the rating and performance data for the Caucasian faces replicated Vokey and Read's (1992) finding that typicality is composed of two orthogonal components, dissociable via their independent relationships to: (1) attractiveness and familiarity ratings and (2) memorability ratings. For Japanese faces, however, we found that typicality was related only to memorability. Where performance measures were concerned, two additional principal components dominated by criterion and by d' emerged for Caucasian faces. For the Japanese faces, however, the performance measures of d' and criterion merged into a single component that represented a second component of typicality, one orthogonal to the memorability-dominated component. A measure of face representation quality extracted from an autoassociative neural network trained with a majority of Caucasian faces and a minority of Japanese faces was incorporated into the principal components analysis. For both Caucasian and Japanese faces, the neural network measure related both to memorability ratings and to human accuracy measures. Combined, the human data and simulation results indicate that the memorability component of typicality may be related to small, local, distinctive features, whereas the attractiveness/familiarity component may be more related to the global, shape-based properties of the face.

Asian People↗
PubMed1988

The factor structure of the GHQ-60 in a community sample.

The factor structure of the 60-item version of the General Health Questionnaire was explored, using data collected in a community study in a rural area of northern Spain. Six principal components, similar to those previously reported with this instrument, were found to provide a good description of the data structure. The 30-item and 12-item versions of the GHQ were then disembedded from the parent version, and further principal components analyses carried out. Again, the results were similar to previous studies: in each of the three versions analysed here, the two most important components represented a disturbance of mood ('general dysphoria')--including aspects of anxiety, depression and irritability--and a disturbance of social performance ('social function/optimism'). The principal component structure of the GHQ-60 was then utilized to calculate factor scores, and these were compared with PSE ratings using Relative Operating Characteristic (ROC) analysis. While four of the six factors discriminated well (area under the ROC curve 0.75 or more) between PSE 'cases' and 'non-cases', only one, depressive thoughts, was a good discriminator between depressed and non-depressed PSE 'cases'.

Adolescent↗
PubMed1985

Comparative study of vibration disease among operators of vibrating tools by factor analysis.

Principal component analysis was carried out to determine the interrelationships between subjective symptoms experienced by workers using various types of vibrating tools (brush saws (41), rock drills (39), chipping hammers (42) and chain saws (49)) and control groups (clerks (44), farmers (42)). The characteristics of the patterns of common factors extracted from these symptoms and the frequency distribution of the factor score of the main principal components were compared among the groups. From a wide variety of symptoms, a principal component related to peripheral nerves, muscles, and joints and a component related to peripheral circulation were extracted specifically and separately. The complaints of rock drillers reflected peripheral circulatory factor and those of chain saw users presented a complex factor of nerve muscle, and joints.

Adult↗
PubMed2002

Characterization of a cross-reactive electronic nose with vapoluminescent array elements.

A three-channel cross-reactive sensor array based on vapoluminescent platinum(II) double salt materials has been characterized. Two arrays were studied, one consisting of [Pt(CN-cyclododecyl)4][Pt(CN)4] (1), [(phen)Pt(CN-cyclohexyl)2][Pt(CN)4] (2), and [Pt(CN-n-tetradecyl)4][Pt-(CN)4] (3) materials, where phen = 1,10-phenanthroline, and a second array that has compound 3 replaced by the mixed double salt material [(phen)Pt(CN-cyclododecyl)Cl)]2[(phen)Pt(CN-cyclododecyl)2]2[Pt(CN)4]3 (4). Compounds 2, 3 and 4 are characterized here for the first time. Inclusion of solvent vapors into these materials often leads to dramatic shifts in their solid-state absorption and luminescence spectra. In these studies the arrays were exposed to a set of 10 test solvent vapors to determine the ability of each cross-reactive array to give reproducible vapoluminescent spectra characteristic of each solvent vapor. It was discovered that temperature programming between solvent vapor exposures greatly improved the reproducibility of the luminescence spectra obtained. A statistical analysis of three-dimensional resolution factors between pairs of solvent clusters in principal component space supported this assertion. The success of the temperature programming protocol was limited by the thermal stability and the sensitivity to low background water vapor levels of some platinum(II) double salt materials. The ability of the cross-reactive sensor array to differentiate between two different solvent vapors over a large concentration range was also investigated. Acetone and methanol were found to occupy two distinct regions of the three-dimensional principal component space. Detection limits for acetone and methanol were estimated from the principal component analysis as 75 and 6 g/m3, respectively.

Journal Article↗
PubMed2002

Effects of lead on 4-aminobiphenyl pharmacokinetics in liver, kidney, spleen, testes, heart, lung and hemoglobin adduct for rat model.

Lead affects almost every system in the body and 4-aminobiphenyl increases the incidence of bladder cancer among human exposed to aromatic amines, but little attention has been paid to the effects of lead (heavy metals) on the distribution and metabolic kinetics of 4-ABP (organic pollutants) in the organisms of the terrestrial ecosystems. In this study, male S.D. rats as model animals drinking tap water with and without lead with i.p. injection of 4-aminophenyl were used to study 4-aminobiphenyl pharmacokinetics with statistical analysis in three types of information systems: (1) hemoglobin adduct in the blood; (2) distribution concentrations in liver, kidney, spleen, testes, heart and lung; (3) relative weights of the six organs. Kinetic equations of 4-aminobiphenyl-hemoglobin adduct for two groups of rats drinking water with and without lead were all linear. Principal components were obtained based on three types of variants: (1) variants of distribution concentrations; (2) variants of relative weights; (3) variants of hemoglobin adduct, distribution concentrations and relative weights. Through a comparison of two groups of principal components, the result implied that lead changed 4-aminobiphenyl distribution kinetics in the six organs, had significant effects on the six organ relative weights, and had also significant effects on all thirteen variants as a whole. Correlation analysis of the principal components showed that lead could not significantly change the relation of hemoglobin adduct with time after dosing 4-aminobiphenyl. However, another result indicated that lead considerably improved the correlation between hemoglobin adduct and the thirteen variants as a whole. This implied that hemoglobin adduct could characterize all the thirteen variants as an index of 4-aminobiphenyl pharmacokinetics for the rats drinking water with lead, which conclusion was not suitable for the rats drinking water without lead. The research indicated that heavy metals existing in the organisms play an important role in the studies on pharmacotoxicology of organic pollutants. Frequently, various xenobiotics (heavy metals and organic pollutants) enter organisms simultaneously, therefore heavy metals should be considered comprehensively in the pharmacotoxicology of organic pollutants in animals in the terrestrial ecosystems theoretically and practically.

Aminobiphenyl Compounds↗
PubMed2000

Comparative investigation of concentrations of major and trace elements in organic and conventional Danish agricultural crops. 1. Onions (Allium cepa Hysam) and peas (Pisum sativum ping pong).

210 samples of onions (Allium cepa Hysam) from 11 conventionally and 10 organically cultivated sites and 190 samples of peas (Pisum sativum Ping Pong) from 10 conventionally and 9 organically cultivated sites in Denmark were collected and analyzed for 63 and 55 major and trace elements, respectively, by high-resolution inductively coupled plasma mass spectrometry. Sampling, sample preparation, and analysis of the samples were performed under carefully controlled contamination-free conditions. Comparative statistical tests of the element concentration mean values for each site show significantly (p < 0.05) different levels of Ca, Mg, B, Bi, Dy, Eu, Gd, Lu, Rb, Sb, Se, Sr, Ti, U, and Y between the organically and conventionally grown onions and significantly (p < 0.05) different levels of P, Gd, and Ti between the organically and conventionally grown peas. Principal component analysis (PCA) applied to the 63 elements measured in the individual onion samples from the 21 sites split up the sites into two groups according to the cultivation method when the scores of the first and third principal components were plotted against each other. Correspondingly, for peas, a PCA applied to the 55 elements measured as mean values for each site split up the 19 sites into two groups according to the cultivation method when the scores of the third and fourth principal component were plotted against each other. The methodology may be used as authenticity control for organic cultivation after further method development.

Food, Organic↗
PubMed2004

The nosology of sub-acute and chronic fatigue syndromes that follow infectious mononucleosis.

BACKGROUND: A previous principal components analysis of symptoms occurring after infectious mononucleosis suggested that a discrete fatigue syndrome occurs, which is independent of psychiatric disorder. This work has not been replicated and no latent class analysis of subjects has been published. METHOD: We prospectively examined a cohort of 150 American primary care patients 2 and 6 months after the onset of corroborated infectious mononucleosis. A subset of 50 subjects was studied 4 years after onset. We performed principal components analyses of both psychological and somatic symptoms and latent class analyses of subjects. RESULTS: Principal components analyses consistently delineated two fatigue factors at 2 and 6 months and one fatigue factor at 4 years. These factors were separate from a mixed anxiety and depressive factor. A four-class solution for the latent class analyses consisted of most subjects with few symptoms, a few with many symptoms, a group with predominantly mood symptoms and some subjects with fatigue symptoms. CONCLUSIONS: The symptoms of the principal factors with fatigue were similar to those previously described. Both the factors and classes were independent of an equally delineated mood factor and class. These results support the existence of two discrete chronic fatigue syndromes after infectious mononucleosis, one of which is still demonstrable 4 years after onset.

Acute Disease↗