Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Structural validation”

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 1,171 records · Page 65Linked to original sources
PubMed2005

Genetic and environmental etiology of effortful control.

We examined whether effortful control (EC), a temperament proposed by Rothbart and Bates (1998), has genetically coherent structure. A self-report measure of EC was administered to 450 Japanese twins (151 males and 299 females, ages 17 to 32 years) including 152 monozygotic and 73 dizygotic pairs. Univariate genetic analysis revealed that AE model fit best for the total EC as well as its subscales. The heritability estimate for total EC was 49%, and the estimates for subscales ranged between 32% and 45%. Multivariate genetic analysis revealed that the subscales of EC were genetically correlated to a high degree and environmentally correlated to a moderate degree. These results suggest that EC has substantial genetic basis and genetically coherent structure, supporting the validity of the construct. The implications to molecular genetic study and study of psychopathology were discussed.

Adolescent↗
PubMed2005

Identification of nitric oxide donors by biomimetic HTS application.

Metalloporphyrin catalyzed biomimetic oxidation was used for the identification of nitric oxide (NO) donors with diverse chemical structure. Methodology was validated by testing known NO donors. Efficient automation of the test allowed us to investigate a subset of our corporate library. Several hits identified in this campaign were validated in both the chemical and also microsomal model that revealed all hits to be active in the biological system, as well. One of the hits showed comparable activity to V-PYRRO/NO, the prototypic liver selective NO donor.

Animals↗
PubMedDate not supplied

A Global Assessment of Recent Stress (GARS) Scale.

The Global Assessment of Recent Stress (GARS) Scale was developed to assess current stress perception. Most measurements of environment are derived from life event scales that capture amount of stress or change associated with stressful events that have occurred over the past six to twenty-four months. A scale that provides a more immediate estimate of stress is needed when physiological tests and perceived stress are studied together. The GARS has been subjected to a series of studies concerning its reliability, validity, and factor structure. Results suggest that it may be a useful instrument for helping individuals assess their current feelings of stress.

Adult↗
PubMed2005

Bayesian statistical studies of the Ramachandran distribution.

We describe a method for the generation of knowledge-based potentials and apply it to the observed torsional angles of known protein structures. The potential is derived using Bayesian reasoning, and is useful as a prior for further such reasoning in the presence of additional data. The potential takes the form of a probability density function, which is described by a small number of coefficients with the number of necessary coefficients determined by tests based on statistical significance and entropy. We demonstrate the methods in deriving one such potential corresponding to two dimensions, the Ramachandran plot. In contrast to traditional histogram-based methods, the function is continuous and differentiable. These properties allow us to use the function as a force term in the energy minimization of appropriately described structures. The method can easily be extended to other observable angles and higher dimensions, or to include sequence dependence and should find applications in structure determination and validation.

Journal Article↗
PubMed1995

Morphometric analysis of epithelial components and dentinoid formation in non-neoplastic calcifying odontogenic cyst.

Calcifying odontogenic cysts (COCs) represent a group of lesions that may be broadly classified into two main entities: cysts and neoplasms. In the present study 30 non-neoplastic cystic COCs were examined by a quantitative histological method in an attempt to calibrate the relative distribution of the type of epithelial lining, intensity of ghost cell formation and the amount of dentinoid present. The results showed that there are two main types of cystic COC: an odontoma-producing type and a non-odontoma-producing variant. Morphologically, tooth-like structures were a valid distinguishing feature, while morphometrically the odontoma-producing variant showed a greater amount of luminal and mural dentinoid as well as luminal ghost cells. Demographic analysis also revealed that the odontoma-producing COC occurred in younger patients and showed an even sex distribution, whereas the non-odontoma-producing type was seen in older patients and showed a predilection for females. Both subtypes were more prevalent in the Chinese population and occurred preferentially in the maxilla.

Adolescent↗
PubMed1989

Study of ideal-self discrepancy and observed social behaviors in a therapeutic community.

This descriptive study explored relations between ideal self-discrepancy (often referred to as self-esteem or self-concept) and behaviors observed in 27 residents of a therapeutic community for polydrug users. The Sliding Person Test (SPERT), an abstract, nonverbal measure of self-reported, ideal self-discrepancy was administered three times a week, for seven consecutive weeks to 27 subjects after regularly scheduled group meetings. Data were charted on graphs to reveal fluctuations of ideal self-discrepancy and incidences of observed, documented changes in behavior. Analysis suggests the instrument detects some changes in ideal self-discrepancy congruent with transitional behaviors. In more than half of the cases, fluctuation of 25% or more in discrepancy between ideal self-concept and at-the-moment self-concept was directly related to an observed change in behavior or residents' transition in the hierarchy of the program's structure. Implications for validity and reliability issues concerning measures of ideal-self-discrepancy are briefly discussed.

Humans↗
PubMed1991

Cross-cultural application of the Center for Epidemiological Studies Depression Scale: a study of black South African students.

This article reports normative and psychometric data for the Center for Epidemiological Studies Depression Scale when used with black South African students. Subjects were 450 undergraduate students in psychology. The reliability, validity, and factor structure of the scale were consistent with previously reported findings. The correlations of CES-Depression Scale scores with certain demographic variables are also reported.

Adult↗
PubMed1994

Revision and further assessments of the Prison Locus of Control Scale.

The report of initial measurements studies conducted on the Prison Locus of Control Scale concluded with suggestions for altering the format and content to improve the psychometric properties of the scale. This paper is a report of structural, reliability, and validity studies conducted on the revised Prison Locus of Control Scale. Assessments included a test of internal consistency, factor analyses, one test each of concurrent and known-groups validity, and four tests of construct validity. The results show strong support for the reliability and validity of the revised scale, which is provided in an appendix.

Adult↗
PubMed2005

Evaluating psychometric properties of Farsi version of the Positive and Negative Perfectionism Scale.

This study examined the psychometric properties of the Farsi version of the Positive and Negative Perfectionism Scale. Two samples of 97 (56 women, 41 men) and 115 (67 women, 48 men) undergraduate students at the University of Tehran participated. Findings supported the internal consistency, test-retest reliability, concurrent validity, and factor structure of the Farsi version. Factor analysis provided evidence for two dimensions of perfectionism, Positive and Negative perfectionism. The two dimensions had significant negative and positive correlations, respectively, with measures of psychological distress and health, respectively. The Farsi version of the Positive and Negative Perfectionism Scale presented good psychometric properties for use in research.

Achievement↗
PubMed1988

Psychopathology of opiate addiction: comparative data from the MMPI and MCMI.

The MMPI and MCMI were administered to 163 former opiate addicts who were being maintained in a methadone program affiliated with an urban hospital. Highest group mean MMPI scores were found for Psychopathic Deviate, Depression, Hypomania, and Hysteria. For the MCMI, highest group mean clinical syndrome scores were found for Drug Abuse, Alcohol Abuse, Anxiety, and Dysthymia; highest personality disorder scores were found for Antisocial, Narcissistic, Histrionic, and Paranoid. The MCMI Drug Abuse Scale identified only 49% of subjects as having a recurrent or recent history of drug abuse. Frequency and factor analyses documented the heterogeneity of the population with respect to clinical syndromes, as well as the prevalence of personality disorders (86% had elevations on MCMI Personality Scales). Factor and correlational analyses did not provide strong evidence of similar factor structure or convergent validity of the MMPI and MCMI with this population.

Adult↗
PubMed2006

The physical performance test and the evaluation of functional status in patients with cerebral aneurysms.

OBJECT: Cerebral aneurysms can adversely affect the functional status of patients who harbor them through rupture, mass effect, or treatment sequela. The authors compared the Physical Performance Test (PPT)--an observer-administered test requiring the completion of seven tasks--with three functional status measures based on patient self-reports: the Glasgow Outcome Scale (GOS), the modified Rankin Scale (mRS), and the modified Barthel Index (mBI). METHODS: Data were collected from 144 patients with aneurysms who had been recruited from a neurosurgery clinic. The patients completed the PPT and were assigned GOS scores, mRS scores, and mBIs based on their responses during a structured interview. The validity of the PPT was assessed by examining the relationship between the results of the PPT and the values assigned to each patient by using the GOS, mRS, and mBI by applying rank-order methods; the reliability of the PTT was assessed using the Cronbach alpha coefficient. The mean age of the patients was 52.8 years; 72% were women and 54% had survived a subarachnoid hemorrhage. The mean +/- standard deviation PPT score was 24.0 +/- 3.7. The PPT generated a broad distribution of scores, whereas GOS and mRS scores and mBIs displayed significant ceiling effects, that is, 75% of the patients were clustered in the highest categories. The PPT scores were validated by their strong association with GOS scores, mRS scores, and mBIs (for all, p < 0.001), and the reliability of the PPT was demonstrated by a Cronbach alpha value of 0.77. CONCLUSIONS: The PPT provides an objective measure of functional status in patients with cerebral aneurysms. The results suggest that the PPT may differentiate among patients better than the GOS, mRS, or mBL The PPT is a valid and reliable instrument for measuring functional status in patients with cerebral aneurysms.

Activities of Daily Living↗
PubMed1976

[Ultrastructure of the enterocytes of the upper 3d of the villi of murine small intestine].

The enterocytes of the upper one-third of the villi of duodenum, ileum and jejunum of mice were investigated with the electron microscope. It was found that enterocytes moving to the top of the villus underwent regular structural rearrangements that involve the appearance of triangular dilatations of the intercellular spaces at the cell base, condensation of the mitochondrial matrix, reduction of ergastoplasmic reticulum and dictyosome hypertrophy. It is suggested that enterocytes leave the top of the villus as structurally and functionally valid cells.

Animals↗
PubMed1999

Adolescent reputation enhancement: differentiating delinquent, nondelinquent, and at-risk youths.

This research reports the findings of two studies conducted to measure and then investigate differences between delinquent, nondelinquent, and at-risk youths' orientations towards reputation enhancement. In the first study, concerning item selection and scale development, the factor structure and content validity of a potential Reputation Enhancement Scale were tested by examining the item responses of the scale completed by 230 high-school students. In the second study, the scale was validated by comparing the item responses of 80 delinquent, 90 at-risk, and 90 nondelinquent adolescents with the responses of the original students. The instrument was found to be reliable (alphas from .64 to .92), indicating that the factors are dependable across different samples, and the coefficients of congruence were sufficiently high to investigate meaningful group differences. Three second-order factors (Conforming Reputation, Nonconforming Reputation, Self-presentation) were derived from the 15 first-order factors. Although multivariate analyses revealed significant differences between the reputational orientations of delinquent, at-risk, and nondelinquent participants, the self-presentation second-order factor did not differentiate the three groups.

Adolescent↗
PubMed1999

Dental beliefs, knowledge and behaviour of Chinese people in the United Kingdom.

OBJECTIVE: This study explored oral health beliefs, knowledge and behaviour among a sample of United Kingdom Chinese. DESIGN: A quota sample of Chinese people, stratified by age and gender, were interviewed by trained and standardised Chinese interviewers using a piloted, validated semi-structured questionnaire. SUBJECTS: One hundred and fifty-six Chinese people--with similar number of teenagers, younger adults and older people--resident in the North East of England. SETTING: Chinese communities. OUTCOME MEASURE: Reported dental knowledge, beliefs and behaviours. RESULTS: Regardless of gender and age, the majority of respondents believed that it was natural for people to lose all their teeth in old age. Less than half were convinced that they would be able to keep their own teeth for life. The majority of the sample considered that they were susceptible to dental diseases, the consequences of which were thought to be serious. Approximately half presumed that dental diseases were preventable, although the aetiology of dental caries, periodontal disease and tooth loss was poorly understood. While 94% claimed to brush their teeth as part of routine dental care, dental visiting and dietary restriction of sugar intake were reported only in 61% and 30% of the sample respectively. Inter-generational differences were marked; older people tended to have a fatalistic attitude and were least likely to attend the dentist. CONCLUSIONS: A low level of dental awareness was found among the UK Chinese. In order to facilitate effective health promotion and treatment services, the extent of Chinese people's traditional oral health beliefs and behaviour must be taken into account.

Adolescent↗
PubMed1997

Health-related self-report (HRSR) scale: the diagnostic screening test for depression in Thai population.

In this study we introduced a health-related self-report (HRSR) diagnostic scale for detecting depression in Thai population. The scale composed of 20 symptom items including two objective signs (people said I look worried or sad) and previous suicidal attempt both of which were helpful in detecting and confirming depression and suicidal risk. There were 3 positive items (feel well, life is pleasant and meaningful and feel self-worth) which clearly distinguished normal subjects and depressed patients. The reliability coefficient (Chronbach's alpha) of the HRSR scale was 0.91 and was found to possess a clear factorial structure and clinical validity. The cut-off score at 30 gave 90.2 per cent specificity and 85.3 per cent sensitivity for major depression. Score > or = 25 provided higher specify (93.4%) but lower sensitivity (75.1%) and could detect probable cases of depression or other mental illnesses in the community. Thus it can be used as a diagnostic screening instrument.

Adolescent↗
PubMed2001

Factor structure and explanatory variables of the Mini-Mental State Examination (MMSE) for elderly persons in Taiwan.

BACKGROUND AND PURPOSE: The Mini-Mental State Examination (MMSE) is commonly used in studies and clinical assessment of cognitive functioning. The purpose of this study was to examine the factor structure and variables explaining the scores of the MMSE in elderly persons in Taiwan, in order to provide a reference for instrument selection and data collection for clinicians and researchers. METHODS: Secondary data from an epidemiologic study that included 1,442 randomly selected subjects aged 64 to 98 with an average age of 72.6 years were used. Males comprised 57.1% of the sample, and females 42.9%. Exploratory and confirmatory factor analysis and covariance structure modeling were used to analyze the data. RESULTS: In the cross validation of the covariance structure modeling, 50.1% of the variance in simple processing, 86.9% in complex processing, and 66.9% in memory/attention were explained. Better education background predicted better score in complex processing ability (path coefficient = .860). Greater independence in self-care ability predicted better scores in simple processing (path coefficient = -.716) and memory/attention (path coefficient = -.811). CONCLUSION: The results of this study indicate that items in the MMSE measuring complex processing ability including writing, reading and obeying, and copy design are seriously biased by educational background, and that the remaining items are better indicators of the subject's cognitive functioning for elderly persons in Taiwan. In our model, self-care ability was strongly related to cognitive functioning as measured by the MMSE, especially for items in the factors of simple processing (registration, naming, repetition, and commanding) and attention/memory (orientation to place and time, attention, and recall).

Activities of Daily Living↗
PubMed2002

Aquatic effects assessment: needs and tools.

In the assessment of the adverse effects pollutants can produce on exposed ecosystems, different approaches can be followed depending on the quality and quantity of information available, whose advantages and limits are discussed with reference to the aquatic compartment. When experimental data are lacking, a predictive approach can be pursued by making use of validated quantitative structure-activity relationships (QSARs), which provide reliable ecotoxicity estimates only if appropriate models are applied. The experimental approach is central to any environmental hazard assessment procedure, although many uncertainties underlying the extrapolation from a limited set of single species laboratory data to the complexity of the ecosystem (e.g., the limitations of common summary statistics, the variability of species sensitivity, the need to consider alterations at higher level of integration) make the task difficult. When adequate toxicity information are available, the statistical extrapolation approach can be used to predict environmental compatible concentrations.

Animals↗
PubMed2002

Improving fold recognition of protein threading by experimental distance constraints.

We present a comprehensive analysis of methods for improving the fold recognition rate of the threading approach to protein structure prediction by the utilization of few additional distance constraints. The distance constraints between protein residues may be obtained by experiments such as mass spectrometry or NMR spectroscopy. We applied a post-filtering step with new scoring functions incorporating measures of constraint satisfaction to ranking lists of 123D threading alignments. The detailed analysis of the results on a small representative benchmark set show that the fold recognition rate can be improved significantly by up to 30% from about 54%-65% to 77%-84%, approaching the maximal attainable performance of 90% estimated by structural superposition alignments. This gain in performance adds about 10% to the recognition rate already achieved in our previous study with cross-link constraints only. Additional recent results on a larger benchmark set involving a confidence function for threading predictions also indicate notable improvements by our combined approach, which should be particularly valuable for rapid structure determination and validation of protein models.

Nuclear Magnetic Resonance, Biomolecular↗