Dynamics of differentiation: Similarity as the precursor and product of stereotype formation.

The degree of data-based and expected coherence within groups was predicted to enhance intergroup differentiation in the illusory correlation paradigm. Results of Study 1 indicated that data-based coherence was a prerequisite for illusory correlation, and this effect was further enhanced by expected coherence. Reinterpretations of the behaviors also augmented illusory correlation, especially when instructions provided greater scope for this, but only under conditions of data-based coherence. The finding that group coherence enhances illusory correlation contradicts recent findings of A. R. McConnell, S. J. Sherman, and D. L. Hamilton ( 1997). This anomaly was resolved by showing that the relation between group coherence and illusory correlation is curvilinear (Study 2). Illusory correlation increased with coherence but diminished when group coherence was sufficiently high to undermine meaningful evaluative differentiation between groups. Results showed that intragroup similarity is both a precursor and a product of differentiation and illusory correlation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Centrality and energy dependence of rapidity correlation patterns in relativistic heavy ion collisions

The centrality and energy dependence of rapidity correlation patterns are studied in Au＋Au collisions by using AMPT with string melting, RQMD and UrQMD models. The behaviors of the shortrange correlation （SRC） and the long-range correlation （LRC） are pres     

Serum inhibin B in healthy pubertal and adolescent boys: relation to age, stage of puberty, and follicle-stimulating hormone, luteinizing hormone, testosterone, and estradiol levels

Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, testosterone, and estradiol all increased significantly between stages I and II of puberty. From stage II of puberty the inhibin B level was relatively constant, whereas the FSH level continued to increase between stages II and III. From stage III of puberty the FSH level was also relatively constant, although there was a nonsignificant trend of slightly decreased FSH levels at pubertal stage V compared to stage IV. The levels of serum LH, testosterone, and estradiol increased progressively throughout puberty. In prepubertal boys younger than 9 yr, there were no correlation between inhibin B and the other three hormones. In prepubertal boys older than 9 yr, a significant positive correlation was observed between inhibin B and FSH, LH, and testosterone. However, at this pubertal stage, each hormone correlated strongly with age, and when the effect of age was taken into account, only the partial correlation between inhibin B and LH/testosterone remained statistically significant. At stage II of puberty, the positive partial correlation between inhibin B and LH/testosterone was still present. At stage III of puberty, an negative partial correlation between inhibin B and FSH, LH, and estradiol was present, whereas no correlation between inhibin B and testosterone could be observed from stage III onward. The negative correlation between inhibin B and FSH persisted from stage III of puberty onward, whereas the correlation between inhibin B and LH and between inhibin B and estradiol was nonsignificant at stages IV and V of puberty. In conclusion, in boys, serum inhibin B levels increase early in puberty; by pubertal stage II the adult level of inhibin B has been reached. The correlation of inhibin B to FSH, LH, and testosterone changes during pubertal development. Early puberty is characterized by a positive correlation between inhibin B and LH/testosterone, but no correlation to FSH. Late puberty (from stage III) is characterized by a negative correlation between inhibin B and FSH (which is maintained in adult men), a diminishing negative correlation between inhibin B and LH, and no correlation between inhibin B and testosterone, suggesting that developmental and maturational processes in the hypothalamic-pituitary-gonadal axis take place, leading to the establishment of the closed loop feedback regulation system operating in adult men. The positive correlation between inhibin B and LH/ testosterone at the time when serum inhibin B levels rise early in puberty suggests that Leydig cell factors may play an important role in the maturation and stimulation of Sertoli cells in the beginning of pubertal development.     

相关性检验在地电化学（泡塑）和偏提取样品金及伴生元素分析质量评估中的应用

利用最小二乘法分别对湖南龙山金锑矿区41～46线126件地电化学（泡塑）法样品中Au和Sb,阳山矿区和寨上矿区偏提取样品中金与砷锑汞的综合异常（As-Sb-Hg）进行了线性相关性统计检验,得到的相关系数分别为0.895和0.859,均大于临界值0.811,表明Au与伴生元素显著相关。检验结果与已知的矿区地球化学元素异常组合特征相吻合,以此作为评估分析质量的依据,认为分析结果可靠。在没有合适标准物质或重复样监控情况下,提出了化探分析元素相关性质量评估方法,有利于地球化学找矿新技术、新方法的推广应用。     

On the bipolarity of positive and negative affect

Is positive affect (PA) the bipolar opposite of, or is it independent of, negative affect (NA)? Previous analyses of this vexing question have generally labored under the false assumption that bipolarity predicts an invariant latent correlation between PA and NA. The predicted correlation varies with time frame, response format, and items selected to define PA and NA. The observed correlation also varies with errors inherent in measurement. When the actual predictions of a bipolar model are considered and error is taken into account, there is little evidence for independence of what were traditionally thought opposites. Bipolarity provides a parsimonious fit to existing data.     

Skew and internal consistency.

The effects of skew on the standardized item alpha were examined with Monte Carlo techniques. Alphas computed from normal variables were compared with alphas from lognormal variables, ranks, and skewed versus normal Likert-type variables. The extent and direction of skew were varied, as was the size of the population interitem correlation (rho), the number of items, and the number of categories for Likert-type variables. Because the average interitem correlation affects alpha and skew affects the average interitem correlation, the effect of skew on the average interitem correlation also was examined. Results indicated that skew decreased the average interitem correlation and produced small decreases in alpha that were largest when skew was large, rho was small, items were skewed in opposite directions, and there were fewer items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genotype-environment interaction and correlation in the analysis of human behavior.

Two issues that complicate behavioral genetic analyses are the interaction and correlation between genetic and environmental influences. In the present report, the effects of genotype-environment interaction and correlation on behavioral genetic studies (twin and adoption studies) are examined. The analysis suggests that genotype-environment interaction may bias twin study estimates of genetic and environmental influence but need not affect adoption studies. On the other hand, genotype-environment correlation may affect both twin and adoption study estimates of genetic and environmental influence, the direction of the effect depending on the sign of the correlation. New tests of genotype-environment interaction and correlation, using adoption data, are proposed. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing squared multiple correlation coefficients: Examination of a confidence interval and a test significance.

I. Olkin and J. D. Finn (1995) presented 2 methods for comparing squared multiple correlation coefficients for 2 independent samples. In 1 method, the researcher constructs a confidence interval for the difference between 2 population squared coefficients; in the 2nd method, a Fisher-type transformation of the sample squared correlation coefficient is used to obtain a test statistic. Both methods are based on asymptotic theory and use approximations to the sampling variance. The approximations are incorrect when the population multiple correlation coefficient is zero. The 2 procedures were examined for equal and unequal population multiple correlation coefficients in combination with equal and unequal sample sizes. As expected, the procedures were inaccurate when the population multiple correlation coefficients were zero or very small and, in some conditions, were inaccurate when sample sizes and coefficients were unequal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relations between observer-rating and self-report of depressive symptomatology.

Sources of discrepancy between the Hamilton Rating Scale for Depression (HRSD) and the Beck Depression Inventory (BDI) were investigated in 114 depressed inpatients treated with ECT. Three previously reported observations were found to occur within the same sample: (1) There was only a moderate baseline correlation between the measures; (2) this correlation improved markedly at later assessment; (3) the HRSD had a greater effect size for change. The modest baseline correlation was largely due to patients who rated themselves as substantially less depressed than clinicians had rated them. Improvement in the correlation with repeated assessment was due to the representation of clinical responders. The larger effect size with the HRSD was mainly attributable to a small subgroup that showed marked deterioration on the BDI, a phenomenon not observed with clinical evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of smoking cessation on insulin and cardiovascular risk factors--a controlled study of 4 months'' duration

MIB-1 Ki-67 and PCNA scores in infiltrating ductal NOS breast carcinomas were compared. The correlation between MIB-1, Ki-67 and PCNA indices and several clinicopathological factors that have prognostic significance in breast cancer was also assessed. The mean Ki-67, MIB-1 and PCNA indices were 13.4%, 19.4%, 27.6%, respectively. Significant positive linear correlation was found only between Ki-67 and MIB-1 indices. PCNA score did not correlate with Ki-67 and MIB-1 indices. The significant correlation between Ki-67 and MIB-1 scores and histological grade was found. There was no correlation between Ki-67 and MIB-1 indices and axillary lymph node status or tumor diameter. The results suggest that MIB-1 antibody is an excellent tool for assessment of proliferative rate of breast cancer cells in paraffin sections.     

On the sampling variance of intraclass correlations and genetic correlations

Widely used standard expressions for the sampling variance of intraclass correlations and genetic correlation coefficients were reviewed for small and large sample sizes. For the sampling variance of the intraclass correlation, it was shown by simulation that the commonly used expression, derived using a first-order Taylor series performs better than alternative expressions found in the literature, when the between-sire degrees of freedom were small. The expressions for the sampling variance of the genetic correlation are significantly biased for small sample sizes, in particular when the population values, or their estimates, are close to zero. It was shown, both analytically and by simulation, that this is because the estimate of the sampling variance becomes very large in these cases due to very small values of the denominator of the expressions. It was concluded, therefore, that for small samples, estimates of the heritabilities and genetic correlations should not be used in the expressions for the sampling variance of the genetic correlation. It was shown analytically that in cases where the population values of the heritabilities are known, using the estimated heritabilities rather than their true values to estimate the genetic correlation results in a lower sampling variance for the genetic correlation. Therefore, for large samples, estimates of heritabilities, and not their true values, should be used.     

Comparison of the blood levels of insulin and growth hormone in healthy adolescents, adolescents with excessive weight and with hereditary loading with regard to diabetes mellitus

Changes in insulin and growth hormone secretion were studied in 112 children and adolescents (50 healthy ones, 40 with excessive weight, and 22 with heredity aggravated by diabetes mellitus). Three types of these changes were distinguished in healthy adolescents: normoreactive, hyperreactive, and inert. The same type of growth hormone secretion changes corresponded to each type of insulin secretion changes. There was revealed a negative correlation between the insulin and growth hormone levels in the group of healthy adolescents. Dynamic relation was noted between the indices of the mentioned hormones in the course of the test: it was stronger during the ascending than during the descending phase of the test. Glucose load proved to change the correlation between the hormones level. In the group of healthy adolescents correlation between the insulin and the growth hormone levels was greater before carbohydrate load than after it. In case of excessive weight or heredity aggravated by diabetes mellitus glucose load disturbed the correlation between the hormones: when a negative correlation existed between the insulin and growth hormone levels before the load no correlation was revealed after in. This fact confirmed the role played by excessive carbohydrate consumption in the pathogenesis of diabetes mellitus.     

Correlation analysis of the changes of EEG mapping and the changes of CT scan in patients with senile dementia

OBJECTIVE: To observe the changes of EEG mapping and CT scan and analyse the correlation between the changes of the function presented by EEG mapping and morphology presented by CT. METHODS: The absolute power of EEG mapping and 9 parameters of CT in 30 normal controls and 31 patients with senile dementia were measured. The correlation was analysed quantitatively with multiple stepwise regression method. RESULTS: The EEG mapping of senile dementia revealed a diffuse increase in delta, theta power and decreased alpha power in most areas. CT scan showed cortical and subcortical atrophy in brain. There were positive correlations between the increase of delta power and lateral fissure, and between the increase of delta power and average cerebral sulcus. There was a negative correlation between the decrease of alpha power and the increase of lateral fissure. CONCLUSION: The EEG mapping and CT in patients with senile dementia are different from those in normal elderly. There is a correlation between the changes of EEG mapping and CT scan.     

Correlation and the coefficient of determination.

Contends that both the interpretation of an effect size and the actual estimation of a coefficient of determination are partially theory-dependent. Two theoretical models for the variables cases are considered. In a variety of circumstances where the square of the correlation is used, the required assumptions are not tenable. In the alternate model, the absolute value of the correlation provides a coefficient of determination. The correlation coefficient is recommended for use as an effect-size indicator, because evaluating effect size in terms of variance accounted for may lead to interpretations that grossly underestimate the magnitude of a relation. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interrelationships between facial areas and other body dimensions

The data from 35 premenarchial Gujarati, Hindu girls, selected at random, in the age range of 120 months to 144 months were collected to find out statistically the nature and the values of correlation coefficients among various facial areas and other body dimensions such as body weight, stature, chronological and skeletal ages. The correlation coefficients between skeletal, chronological, height and weight ages ranged from 0.413 to 0.8105 showing moderately high association. Height and weight ages turned out to be the most reliable indicators of growth and development of facial areas in this age group and the chronological age as in ineffectual indicator of the same. Maxillary and mandibular areas showed a high value of correlation coefficients (0.67) while the orbitoethmoidal area did not show any correlation with any age variables or with other facial areas. The mandibular areas showed the highest correlation with weight age (0.63) and lowest with chronological age (0.431). The maxillary area showed highest correlation with chronological age (0.62) and lowest with skeletal age (0.42). Fifteen empirical formulae have been developed by which average value of facial areas could be predicted from the other variables.     

Correlational structure of the MCMI-III personality disorder scales and comparisons with other data sets

We examine the correlational structure of the personality disorder (PD) scales from the MCMI-III (Millon, 1994) among 614 college students. The correlation matrix from our nonclinical sample was highly similar to the clinical sample matrices reported by Millon (1994). Further analyses revealed that the correlation matrices from a variety of MCMI data sets are generally similar to one another, but are only moderately similar to PD correlation matrices based on other assessment techniques. PD correlation matrices based on different assessment techniques are generally not very similar to one another. Two-, 3-, and 4-factor solutions for the MCMI-III PD scales are reported and provide a framework for integrating apparently conflicting findings from previous work. The 4-factor solution was most meaningful and was consistent with the 5-factor model of PD.     

Structural Health Monitoring and Damage Assessment Using Frequency Response Correlation Criteria

Two frequency response correlation criteria, namely the global shape correlation (GSC) function and the global amplitude correlation (GAC) function, are established tools to quantify the correlation between predictions from a finite-element (FE) model and measured data for the purposes of FE model validation and updating. This paper extends the application of these two correlation criteria to structural health monitoring and damage detection. In addition, window-averaged versions of the GSC and GAC, namely WAIGSC and WAIGAC, are defined as effective damage indicators to quantify the change in structural response. An integrated method of structural health monitoring and damage assessment, based on the correlation functions and radial basis function neural networks, is proposed and the technique is applied to a bookshelf structure with 24 measured responses. The undamaged and damaged states, single and multiple damage locations, as well as damage levels, were successfully identified in all cases studied. The ability of the proposed method to cope with incomplete measurements is also discussed.     

Endogenous levels of somatostatin, C-peptide and insulin in acute pancreatitis

The authors compared in seven patients with acute pancreatitis the levels of endogenous somatostatin, insulin and C-peptide to assess their mutual correlation and relation to the development of the disease and serum amalyse levels. The results were compared with values recorded in 11 healthy volunteers. The levels of endogenous somatostatin were in patients with acute pancreatitis significantly higher (p < 0.05) than in the control group. The authors found an inverse relationship between the somatostatin and amylase level (correlation coefficient 0.75). They did not observe a significant correlation between somatostatin and insulin levels nor between somatostatin and C-peptide levels. The elevated somatostatin level may be due to the counteregulatory reaction during secretion, stimulated by endogenous or exogenous factors (cholecystokinin, alcohol, food).     

Shuttling behavior and intracranial self-stimulation reward: Behavioral changes as a function of intensity and independence of on/off times.

The correlation between "on" and "off" time in intracranial self-stimulation shuttling behavior under continuous reinforcement was examined. The results showed that if a tendency for positive trend in the data was accounted for, no consistent correlation could be found between within-trial on time and the succeeding or preceding off time either as a function of intensity or number of trials. However, mean on and off times showed a significant positive correlation at low to moderate intensities. Total charge, total time, and proportion of time on remain relatively constant over a series of trials despite significant changes in on time, off time, and crossing rate. The results indicate the importance of selecting suitable measures in the study of shuttling behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Holographic detection of fatigue-induced surface deformation and crack growth in a high-strength aluminum alloy

Changes in optical correlation intensity (I)_c are observed during fatigue cycling of 2024-T3 aluminum alloy. TheI _c measurements are made by transmitting light scattered from the specimen surface through a holographic filter containing information about the surface topography at an earlier time. Topographic changes such as slip band development, microcracking, and crack propagation are observed and recordedin situ during fatigue cycling of individual specimens and cause corresponding changes in correlation intensity. A three-stage curve log (I)_c vs number of fatigue cycles is observed for both unnotched and notched specimens. The overall shape of the curve is not affected by the applied stress levels in constant amplitude tests. Thein situ metallographic observations confirm that region A of the correlation intensity curve corresponds to progressive roughening of the specimen surface caused by slip during the early part of the fatigue life, together with a rapid increase in the number of microcracks of the order of a few micrometers in length. Few metallographic changes are observed during region B of the curve, where the correlation intensity remains relatively constant. The accelerating loss of correlation intensity in region C of the curve arises from the elastic and plastic displacements which occur as a crack or cracks grow beyond about 10 μm in length. The metallographic observations also show that for both notched and unnotched specimens, the correlation intensity readings in region C are sensitive to factors such as crack branching, crack-tip plasticity, and changes in crack growth direction as well as to the overall increase in crack length. The total loss of correlation intensity from the beginning of fatigue cycling to the development of a crack about 800 μm in length can be more than eight orders of magnitude at the present sensitivity of our experiments. The optical correlation technique is an extremely sensitive method of detecting remotely, in air, fatigue damage, and the propagation of fatigue cracks from ten to several hundred micrometers in length. The correlation intensity curve provides an indication of developing fatigue damage and impending fatigue failure in individual specimens, and detects the onset of crack propagation with no prior knowledge of the presence or precise location of particular flaws or cracks.