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Results for “Structural validation”

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PubMed2006

Brief report: the Ego Identity Process Questionnaire: factor structure, reliability, and convergent validity in Dutch-speaking late adolescents.

The reliability and validity of a Dutch version of the Ego Identity Process Questionnaire (EIPQ) were evaluated. In Study 1, the instrument was found to exhibit a clear factor structure and acceptable reliability. Using Confirmatory Factor Analysis, both a model with two process factors (Commitment, Exploration) and a model with four content factors (Ideological Commitment, Ideological Exploration, Interpersonal Commitment, Interpersonal Exploration) evidenced a good fit once direction of wording was taken into account. In Study 2, moderate convergence was observed between Commitment and Exploration, and continuous measures of identity statuses and identity styles. The results of both studies combined indicated that the Dutch version of the EIPQ may be recommended as a research tool with college students.

Adolescent↗

PubMed1994

[Validity of the Brief Psychiatric Rating Scale].

The internal structure and validity of terms used in the Brief Psychiatric Rating Scale (Overall and Gorham, 1962) was analyzed. The data which had been gained at the entrance examination of 1557 inpatients with the diagnosis according to ICD-9 (schizophrenia simplex, schizophrenia paranoids, schizoaffective disease depressive type, schizoaffective disease manic type, manic-depressive disease manic phase, manic-depressive disease depressive phase) were processed using stepwise discriminant analysis (SDA). Three-dimensional space defined by SDA provided a sufficient frame of relations for the majority of diagnostic groups. Incomplete component analysis justified the assumption of a relatively stabile internal structure of the method. The findings allow to recommend the Czech version of the scale for the purpose of description of psychic impairments in psychiatry.

Adolescent↗

PubMed1994

The Children's Headache Assessment Scale (CHAS): factor structure and psychometric properties.

This study investigated the content validity, factor structure, and psychometric properties of the Children's Headache Assessment Scale (CHAS), a parent rating scale for identifying environmental variables associated with pediatric headache. In Study 1, input from physicians and psychologists was obtained to develop a revised set of 44 items receiving high endorsement. In Study 2, the questionnaire was administered to parents of 92 child headache sufferers, ages 6-16, and readministered 2 weeks later. An exploratory factor analysis revealed five factors (Disruptive Impact, Social Consequences, Stress Antecedents, Physical Antecedents and Quiet Coping, and Prescription Medication Use) that reflect distinct environmental concomitants of childhood headache. Scale reliabilities (alpha, .64-.82) indicate acceptable internal consistency, and test-retest reliabilities indicate relatively stable factors and items. High scores on the Disruptive Impact factor were associated with more severe, lengthy, and infrequent headache occurrence, lending initial support for the validity of this factor. Overall, the findings support the clinical and research utility of the CHAS in behavioral treatment of childhood headache.

Adolescent↗

PubMed1984

A simplistic approach to structural dysplasia assessment: description and validation.

The purpose of this study was to formulate a simplistic method of assessing human structural dysplasia and to validate a classification system that would objectively categorize the type and extent of such dysplasia through the use of indices. Anthropometric measurements were taken from a sample of 222 male college students, length/breadth ratios were formulated, and upper/lower body classifications were made in terms of type and subtype dysplasia. Correlation validation results were highly significant. Body composition data information was also provided for descriptive purposes.

Adipose Tissue↗

PubMed2004

The forgotten ones? The validity of consideration and initiating structure in leadership research.

This study provided a meta-analysis of the relationship of the Ohio State leadership behaviors--Consideration and Initiating Structure--with leadership. Overall, 163 independent correlations for Consideration and 159 correlations for Initiating Structure were analyzed. Results revealed that both Consideration (.48) and Initiating Structure (.29) have moderately strong, nonzero relations with leadership outcomes. Consideration was more strongly related to follower satisfaction (leader satisfaction, job satisfaction), motivation, and leader effectiveness, and Initiating Structure was slightly more strongly related to leader job performance and group-organization performance. Validities did vary by leadership measure, but in most cases validities generalized regardless of the measure used. Overall, the results provide important support for the validity of Initiating Structure and Consideration in leadership research.

Humans↗

PubMed1996

Cross validation of the factor structure of the 20-item Toronto Alexithymia Scale: an Italian multicenter study.

The 20-item Toronto Alexithymia Scale (TAS-20) has been shown in previous research to measure a general dimension of alexithymia with three intercorrelated factors. This study evaluated the reliability and factorial validity of an Italian translation of the TAS-20 in a group of normal adults (N = 206) and in a mixed group of medical and psychiatric outpatients (N = 642). Using confirmatory factor analyses, the previously established three-factor model of the TAS-20 was found to be replicable in both groups. In addition, the Italian TAS-20 demonstrated adequate estimates of internal reliability and test-retest reliability. Although evaluation of the convergent, discriminant, and concurrent validity of the TAS-20 is required in Italian populations, the present results support the use of the Italian translation of the scale for clinical and research purposes.

Adult↗

PubMed2007

Achieving 80% ten-fold cross-validated accuracy for secondary structure prediction by large-scale training.

An integrated system of neural networks, called SPINE, is established and optimized for predicting structural properties of proteins. SPINE is applied to three-state secondary-structure and residue-solvent-accessibility (RSA) prediction in this paper. The integrated neural networks are carefully trained with a large dataset of 2640 chains, sequence profiles generated from multiple sequence alignment, representative amino acid properties, a slow learning rate, overfitting protection, and an optimized sliding-widow size. More than 200,000 weights in SPINE are optimized by maximizing the accuracy measured by Q(3) (the percentage of correctly classified residues). SPINE yields a 10-fold cross-validated accuracy of 79.5% (80.0% for chains of length between 50 and 300) in secondary-structure prediction after one-month (CPU time) training on 22 processors. An accuracy of 87.5% is achieved for exposed residues (RSA >95%). The latter approaches the theoretical upper limit of 88-90% accuracy in assigning secondary structures. An accuracy of 73% for three-state solvent-accessibility prediction (25%/75% cutoff) and 79.3% for two-state prediction (25% cutoff) is also obtained.

Algorithms↗

PubMed1998

The revised Conners' Parent Rating Scale (CPRS-R): factor structure, reliability, and criterion validity.

The Conners' Parent Rating Scale (CPRS) is a popular research and clinical tool for obtaining parental reports of childhood behavior problems. The present study introduces a revised CPRS (CPRS-R) which has norms derived from a large, representative sample of North American children, uses confirmatory factor analysis to develop a definitive factor structure, and has an updated item content to reflect recent knowledge and developments concerning childhood behavior problems. Exploratory and confirmatory factor-analytic results revealed a seven-factor model including the following factors: Cognitive Problems, Oppositional, Hyperactivity-Impulsivity, Anxious-Shy, Perfectionism, Social Problems, and Psychosomatic. The psychometric properties of the revised scale appear adequate as demonstrated by good internal reliability coefficients, high test-retest reliability, and effective discriminatory power. Advantages of the CPRS-R include a corresponding factor structure with the Conners' Teacher Rating Scale-Revised and comprehensive symptom coverage for attention deficit hyperactivity disorder (ADHD) and related disorders. Factor congruence with the original CPRS as well as similarities with other parent rating scales are discussed.

Adolescent↗

PubMed1999

The relationship between personality and attainment in 16-19-year-old students in a sixth form college. I: Construction of the Student Self-Perception Scale.

BACKGROUND: Of the research that has been undertaken into the relationship between personality and attainment, relatively little exists relating to the 16-19 age range. In a substantive study examining the relationship between academic self-concept, attainment and personality in sixth form students, a first requirement was to design a self-perception instrument. AIMS: The psychometric element of the study aimed to construct a Student Self-Perception Scale (SSPS) that would be effective for students in the FE (further education) context. SAMPLES: The samples comprised a pilot sample of 152 students (aged 16-17 years from two sixth from colleges) and a main sample of 364 students (mean age, 16yrs 10mths, range 16:0 to 18:6 years, from one sixth form college). The main sample included similar numbers of male and female students (46% male, 54% female) and ethnic minority students comprised 14% of this sample. METHOD: An initial item pool of 88 four-point Likert type statements was compiled from comparable existing scales and from responses to a Student Induction Questionnaire. Item analysis was based on oblique factor analysis of the pilot sample responses, followed by cross-validation on the main sample to refine the scale structures. Construct validity was established from the substantive study, especially the Nowicki & Strickland (1973) locus of control results. RESULTS: Exploration of the four- and five-factor structures led to a final specification based on 52 items from five oblique factors. The constituent scales were Passivity (12 items, alpha = .81). Mastery (15 items, alpha = .79), Work Related Inadequacy (11 items, alpha = .72), Extraversion (4 items, alpha = .70) and Social Dependence (10 items, alpha = .66), all statistics compiled from the cross-validation sample. Correlations with Locus of Control ranged from 0.52 for Mastery to -.34 for Work Related Inadequacy. Distribution statistics for Locus of Control matched a comparable American sample. CONCLUSIONS: The five-scale structure exhibits good cross-validation characteristics and supports revealing analyses of relationships within the substantive study. Its 52-item format is suitable for research or exploratory use within its intended FE context.

Achievement↗

PubMed2005

Validation of the binding site structure of the cellular retinol-binding protein (CRBP) by ligand NMR chemical shift perturbations.

We have calculated proton chemical shift perturbations (CSPs) of retinol in the cellular retinol-binding protein (CRBP) through the use of a recently developed computational approach (Wang et al. J. Chem. Phys. 2004, 120, 11392-11400). Excellent agreement with experimental values was obtained for the X-ray structure, whereas the lack of a key hydrogen bond and the distorted isoprene tail of retinol for some NMR models lead to large CSP RMSDs. Therefore, a comparison of computed CSPs of retinol with experiment offers a convenient way to validate the structure of retinol and its orientation in the binding site for the NMR structures.

Binding Sites↗

PubMed2005

The psychotic spectrum: validity and reliability of the Structured Clinical Interview for the Psychotic Spectrum.

This study evaluates the validity and the reliability of a new instrument developed to assess the psychotic spectrum: the Structured Clinical Interview for the Psychotic Spectrum (SCI-PSY). The instrument is based on a spectrum model that emphasizes soft signs, low-grade symptoms, subthreshold syndromes, as well as temperamental and personality traits comprising the clinical and subsyndromal psychotic manifestations. The items of the interview include, in addition to a subset of the DSM-IV criteria for psychotic syndromes, a number of features derived from clinical experience and from a review of the phenomenological descriptions of psychoses. Study participants were enrolled at 11 Italian Departments of Psychiatry located at 9 sites and included 77 consecutive patients with schizophrenia or schizoaffective disorder, 66 with borderline personality disorder, 59 with psychotic mood disorders, 98 with non-psychotic mood disorders and 57 with panic disorder. A comparison group of 102 unselected controls was enrolled at the same sites. The SCI-PSY significantly discriminated subjects with any psychiatric diagnosis from controls and subjects with from those without psychotic disorders. The hypothesized structure of the instrument was confirmed empirically.

Adolescent↗

PubMed2003

Acceptability, validity and reliability of the Structured Clinical Interview for the Spectrum of Substance Use (SCI-SUBS): a pilot study.

This paper reports on the acceptability, reliability and validity of the Structured Clinical Interview for the Spectrum of Substance Use (SCI-SUBS), a new instrument exploring the interactive pathway between substance abuse and psychiatric disorders. Psychiatric outpatients with (n = 21) and without (n = 32) substance abuse comorbidity according to the DSM-IV, non-psychiatric subjects with opioid dependence (OD, n = 14) and normal controls (n = 33) were assessed with the SCI-SUBS. The presence or absence of psychiatric disorders was determined with the Structured Clinical Interview for DSM IV (SCID). The SCI-SUBS was well accepted by participants. The internal consistency of the domains was satisfactory (between 0.64 and 0.93). Domain scores of OD subjects were significantly higher than those of controls and of psychiatric patients without substance abuse. The cut-off point on the SCI-SUBS total score at which there was optimal discrimination between the presence and the absence of a DSM-IV diagnosis of substance abuse was 45. The pilot version of the SCI-SUBS has satisfactory internal consistency and construct validity.

Adult↗

PubMed2002

[The active site of human glucocerebrosidase: structural predictions and experimental validations].

Gaucher disease is a lysosomal storage disorder caused by a deficiency in glucocerebrosidase which cleaves the beta-glucosidic linkage of glucosylceramide, a normal intermediate in glycolipid metabolism. Glucocerebrosidase belongs to the clan GH-A of glycoside hydrolases, a large group of enzymes which function with retention of the anomeric configuration at the hydrolysis site. Accurate three-dimensional (3D) structure data for glucocerebrosidase should help to better understand the molecular bases of Gaucher disease. As such 3D structure data were not available, we used the two-dimensional hydrophobic cluster analysis (HCA) method to make structure predictions for the catalytic domains of clan GH-A glycoside hydrolases. We found that all the enzymes of clan GH-A may share a similar catalytic domain consisting of an (alpha/beta)8 barrel with the critical acid/base and nucleophile residues located at the C-terminal ends of strands beta 4 and beta 7, respectively. In the case of glucocerebrosidase, Glu 235 was predicted to be the putative acid/base catalyst whereas the nucleophile was located at Glu 340. Next, in order to obtain experimental evidence supporting these HCA-based predictions, we used retroviral vectors to express, in murine null cells, E235A and E340A mutant proteins, in which alanine residues unable to participate in the enzymatic reaction replace the presumed critical glutamic acid residues. Both mutants were found to be catalytically inactive although they were correctly folded/processed and sorted to the lysosome. Thus, Glu 235 and Glu 340 do indeed play key roles in the active site of human glucocerebrosidase as predicted by the HCA analysis. In a broader perspective, our work points out that bioinformatics approaches may be highly useful for generating structure-function predictions based on sequence-structure interrelationships, especially in the context of a rapid increase in protein sequence information through genome sequencing.

Amino Acid Sequence↗

PubMed2005

Examining the Community Integration Measure (CIM): a replication study with life satisfaction.

OBJECTIVE: To examine instrument reliability, validity, factor structure, and conceptual underpinnings of the Community Integration Measure (CIM) with the Community Integration Questionnaire Revised (CIQ-R) and the Satisfaction with Life Scale (SWLS). DESIGN: A replication study. SETTING: Community living. PARTICIPANTS: Ninety-one participants: 51 individuals with a brain injury, and 40 without brain injury. MAIN OUTCOMES: Internal consistency, criterion validity, construct validity, discriminant validity factor structure. RESULTS: CIM items produced standardized alphas ranging from 0.72 to 0.83. Significant positive correlations were found among the CIM and both the CIQ-R and SWLS, with the CIM performing better with the SWLS than did the CIQ-R. The CIM discriminated between subject samples as well as by living arrangement. The factor loading solution revealed a three-factor model that explained 63.72 percent of the variance. CONCLUSION: The CIM shows good promise for capturing an individual's perception of community integration. The factor structure supports the original Model of Community Integration. Further research is needed to examine the influence of objective items on the CIM and Model of Community Integration.

Adult↗

PubMed2004

Surface alignment of an elastic body using a multiresolution wavelet representation.

An algorithm for nonlinear registration of an elastic body is developed. Surfaces (outlines) of known anatomic structures are used to align all other (internal) points. The deformation field is represented with a multiresolution wavelet expansion and is modeled by the partial differential equations of linear elasticity. A hierarchical approach that reduces algorithm complexity is adopted. The performance of the algorithm is evaluated by two-dimensional alignment of sections from mouse brains located in the olfactory bulbs. The registration algorithm was guided by manually delineated contours of a subset of brain structures and validated based on another subset of brain structures. The wavelet alignment algorithm produced a twofold to fivefold improvement in accuracy over an affine (linear) alignment algorithm.

Algorithms↗

PubMed1997

Validity and reliability of Structured Interview for Competency Incompetency Assessment Testing and Ranking Inventory.

The Structured Interview for Competency and Incompetency Assessment Testing and Ranking Inventory (SICIATRI) is a structured interview guide to assess the competency for giving informed consent to treatment among psychiatric and medical patients. The competency levels of 48 psychiatric and medical inpatients were assessed by SICIATRI. A relatively high- inter-rater reliability of the SICIATRI items (over half of the items had kappa > or = .60) and concurrent validity (sensitivity = .83, specificity = .67 as measured against the global judgement of competency rating by the attending physician) were obtained. In addition to its brevity (it takes about 20 minutes to complete), these findings may warrant application of this instrument in a clinical setting.

Adult↗

PubMed2005

Work-related subjective experiences among community residents with schizophrenia or schizoaffective disorder.

OBJECTIVE: To develop a self-report scale of subjective experiences of illness perceived to impact on employment functioning, as an alternative to a diagnostic perspective, for anticipating the vocational assistance needs of people with schizophrenia or schizoaffective disorders. METHOD: A repeated measures pilot study (n(1) = 26, n(2) = 21) of community residents with schizophrenia identified a set of work-related subjective experiences perceived to impact on employment functioning. Items with the best psychometric properties were applied in a 12 month longitudinal survey of urban residents with schizophrenia or schizoaffective disorder (n(1) = 104; n(2) = 94; n(3) = 94). RESULTS: Construct validity, factor structure, responsiveness, internal consistency, stability, and criterion validity investigations produced favourable results. Work-related subjective experiences provide information about the intersection of the person, the disorder, and expectations of employment functioning, which suggest new opportunities for vocational professionals to explore and discuss individual assistance needs. CONCLUSION: Further psychometric investigations of test-retest reliability, discriminant and predictive validity, and research applications in supported employment and vocational rehabilitation, are recommended. Subject to adequate psychometric properties, the new measure promises to facilitate exploring: individuals' specific subjective experiences; how each is perceived to contribute to employment restrictions; and the corresponding implications for specialized treatment, vocational interventions and workplace accommodations.

Adolescent↗

PubMed1977

Raman spectral studies of nucleic acids. XVII. Conformational structures of polyinosinic acid.

Laser-Raman spectra of poly(rI) show the formation of an ordered complex in aqueous solutions of high ionic strength. This structure exhibits the A-helix geometry, contains stacked bases and is apparently stabilized by specific hydrogen bonding involving hypoxanthine C6=0 groups. Thermal dissociation of the poly(rI) complex (Tm=45 degrees C) yields single-stranded and disordered poly (RI) chains. A disordered structure also occurs for poly (rI) in aqueous solutions of low ionic strength. In oriented films, poly (rI) forms an ordered structure probably the same as that which occurs in solutions of high ionic strength. Raman intensities measured at 815 and 1100 cm-1 in spectra of poly (rI) and poly (rU)-poly (rA)-poly(rU) indicate that the correlation previously established for single- and double-stranded ribopolymer structures is valid also for these multi-stranded structures. X-ray diffraction and model-building studies confirm the A-helix structure.

Deuterium↗