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PubMed1990

[The validation and usefulness of a questionnaire for evaluating the infrastructure of health centers].

A questionnaire was distributed in all the health centers of the Comunidad Valenciana to establish its validity and usefulness for the evaluation of the physical structure of the health centers. Subsequently, the results were validated by direct verification in 30% of centers. The results of the first part of the questionnaire, related to the type of premises that should be available, and of the second, about the characteristics of such premises, were significantly related with the satisfaction degree (r = -0.724, p less than 0.01), as well as with the criterion of previous planning (p less than 0.001) and the inclusion in structures of a traditional model (p less than 0.001). The 75th percentile of the results of the first and second part of the questionnaire are proposed to select those centers with an unacceptable structure, and, as a quick method, it is recommended to test the parameters of satisfaction degree, previous planning, and inclusion within traditional model structures.

Community Health Centers↗
PubMed2001

Validity of the five-item WHO Well-Being Index (WHO-5) in an elderly population.

BACKGROUND: Depression has a high prevalence in the elderly population; however it often remains undetected. The WHO 5-item Well-Being Index (WHO-5) is a short screening instrument for the detection of depression in the general population, which has not yet been evaluated. The goals of the present study were: 1) to assess the internal and external validity of WHO-5 and 2) to compare the two recent versions of WHO-5. STUDY POPULATION AND METHODS: 367 subjects above 50 years of age were examined with the WHO-5. ICD-10 diagnoses were made using a structured interview (CIDI). The internal validity of the well-being index was evaluated by calculating Loevinger's and Mokken's homogeneity coefficients. External validity for detection of depression was evaluated by ROC analysis. RESULTS: The scale was sufficiently homogeneous (Loevinger's coefficient: version 1 = 0.38, version 2 = 0.47; Mokken coefficient > 0.3 in nearly all items). ROC analysis showed that both versions adequately detected depression. Version 1 additionally detected anxiety disorders, version 2 being more specific for detection of depression. CONCLUSION: The WHO-5 showed a good internal and external validity. The second version is a stronger scale and was more specific for the detection of depression. The WHO-5 is an useful instrument for identifying elderly subjects with depression.

Aged↗
PubMed2002

Feasibility, reliability and validity of the Spanish version of Psychiatric Assessment Schedule for Adults with Developmental Disability: a structured psychiatric interview for intellectual disability.

BACKGROUND: Over 30% of people with intellectual disability (ID) have a comorbid psychiatric disorder. However, there are few assessment instruments available for international use and cross-cultural validation studies of these instruments are rare. The aim of the present study was to standardize the Spanish version of the Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS-ADD-10), a semi-structured interview for people with ID. METHODS: After a conceptual translation, feasibility (i.e. applicability, acceptability and practicality) and reliability analyses were carried out. The predictive validity of the PAS-ADD-10 CATEGO-5 codings was also examined (i.e. positive and negative predictive values). Four independent raters with wide-ranging experience in quantitative evaluation and psychiatric assessment of ID evaluated a sample of 80 subjects with ID and borderline intellectual functioning at the AFANAS occupational centre in Jerez, Southern Spain. The ICD-10 codes were used for psychiatric diagnosis. RESULTS: The practicality of the PAS-ADD-10 is limited because of the need for previous standardization of SCAN interviews. Nevertheless, its overall feasibility was judged adequate by raters and the PAS-ADD-10 was considered extremely useful for training. Test-retest and inter-rater reliability kappa values were moderate to high. The CATEGO coding showed limited validity because of overdiagnosis of anxiety disorders and underdiagnosis of mood and psychotic disorders (positive predictive value = 74%, negative predictive value = 76%). CONCLUSIONS: The PAS-ADD-10 is a useful tool for standard psychiatric assessment of people with ID; however, CATEGO codings show low validity and a series of modifications should be considered before this instrument is used extensively in Spain. In this regard, a study on the clinical usefulness of the PAS-ADD-10 in patients with ID and severe mental disorders has been undertaken.

Adolescent↗
PubMed1995

The structural origins of the unusual specificities observed in the isolation of chymopapain M and actinidin by covalent chromatography and the lack of inhibition of chymopapain M by cystatin.

1. The selectivity observed when the potentially general technique for the isolation of fully active forms of cysteine proteinases, covalent chromatography by thiol-disulphide interchange, is applied to chymopapain M and to actinidin was investigated by a combination of experimentation and computer modelling. Neither of these enzymes is able to react with the original Sepharose-GSH-2-dipyridyl disulphide gel, but fully active forms of both enzymes are obtained by using Sepharose-2-hydroxypropyl-2'-dipyridyl disulphide gel, which is both electrically neutral and sterically less demanding than the GSH gel. Electrostatic potential calculations, minimization and molecular-dynamics simulations provide explanations for the unusual, but different, specificities exhibited by actinidin and chymopapain M in the interactions of their active centres with ligands. 2. The unique behaviour of chymopapain M in exerting an almost absolute specificity for substrates with glycine at the P1 position and in resisting inhibition by cystatin was examined by the computer-modelling techniques. A new, modelled, structure of the complete chicken egg-white cystatin molecule based on the crystal structure of a short form of cystatin was deduced as a necessary prerequisite. The results suggest that electrostatic repulsion prevents reaction of actinidin with the GSH gel, whereas a steric 'cap' resulting from a unique arginine-65-glutamic acid-23 interaction in chymopapain M prevents reaction of the gel with this enzyme and accounts for the lack of its inhibition by cystatin and its specificity in catalysis. 3. Use of chymopapain M as a structural variant of papain demonstrates the validity of the predictions of Lowe and Yuthavong [Biochem. J. (1971) 124, 107-115] relating to the structural requirements and binding characteristics of the S1 subsite of papain.

Binding Sites↗
PubMedDate not supplied

[Validity of operationalized psychodynamic diagnostics].

The paper describes results of "operationalized psychodynamic diagnostics" (OPD) with 54 adolescent and young adult drug addicts prior to outpatient family therapy. Focus of investigation is the prognostic and factorial validity of the OPD-system. Furthermore, relationships between conflicts and psychic structure are investigated. The use of the OPD-system allows a clinical description of the patient sample. Thus, adolescent drug addicts are characterized by autonomy versus dependence and self-esteem conflicts. A neurotic or sometimes borderline level is found on the structure axis. Low scores on the structure axis are significantly correlated with self-esteem conflicts. There is some evidence for the prognostic validity of the OPD I axis. However, prognostic validity of the structure and conflict axes require further research.

Adolescent↗
PubMed2002

Structural differences and functional similarities between two sugar maple (Acer saccharum) stands.

The spatially inexplicit or functional multilayer models used to predict canopy transpiration or photosynthesis are based on the assumption that closed stands show less functional variability than structural variability, because foliage tends to arrange itself in space to optimize the capture of light. To validate this assumption, we compared the structural and functional properties, and the measured and modeled transpiration fluxes of two sugar maple (Acer saccharum Marsh.) stands of comparable leaf mass but differing in height and diameter distributions. One stand was characterized by a well-developed single-layer canopy, whereas the other stand had a multilayered canopy and a stem diameter distribution of the classical inverse-J shape. Stand differences in height and diameter distribution, and canopy gap fraction, were highly significant. There were minor but significant differences in leaf mass and leaf mass per unit leaf area (LMA) distributions. We found no differences in tree-level relationships between basal area and either transpiration flux or sapwood area. We compared measurements of stand transpiration with transpiration estimates obtained from a multilayer gas exchange model, in which only the nonspatial inputs, leaf area index and LMA frequency distribution described stand structure. For both stands, modeled values of daily transpiration closely followed measured values (r(2) = 0.94). These results support use of the nonspatially explicit approach to estimating canopy gas exchange, especially if the intent is to scale-up to larger portions of the landscape.

Acer↗
PubMed2001

Validity in action research: a discussion on theoretical and practice issues encountered whilst using observation to collect data.

AIM: The paper contributes to an understanding of validity in action research methodology by examining issues arising from our attempts to describe the role of an observer in an action research study. BACKGROUND: Our experiences in observing patient care in intensive care settings are used to illuminate discussion on the nature of validity in action research. CONTENT: The paper examines the nature of validity in action research methodology before briefly describing a study that included observing intensive care staff providing patient care. Various perspectives on observation as a research method are critically examined. These include observer role, level of participation, use of cover, structure and timing of observation. Validity in action research underpins the discussion in the paper. CONCLUSION: We conclude that it may not always be possible to categorize the role of the observer within existing definitions. It may be better to summarize the actual observer role as a way of illustrating validity so that the reader can judge the validity of the findings from an action research study.

Critical Care↗
PubMed1998

Determination of the relative precision of atoms in a macromolecular structure.

Several real-space indices and temperature factors are compared with respect to their correlation with atomic positional error and their ability to indicate atoms and residues with the worst of subtle errors. The best index, rED, is a correlation coefficient between model and map electron densities, similar to one proposed earlier, but incorporating two improvements. Firstly, resolution is accounted for explicitly by calculating the model electron density by Fourier transformation of resolution-truncated scattering factors. Secondly, the deviation between model and map electron densities is assigned to neighboring atoms according to their contribution to the electron density of each grid point. With maps of various qualities, rED is the single index with best correlation to atomic error with grouped or individual atoms, and it is the most reliable indicator of poor residues. With poorer omit maps, imprecision of individual atoms is best diagnosed by a combination of low rED or high B factor. With the improved methods, 60-70% of the least precise atoms can detected in a fully refined structure. Similarly, 40-80% of the least precise atoms of an unrefined model can be detected by comparison with an isomorphous replacement map. This is useful in assessing and improving the quality of a model, but not sufficient to confidently validate all atoms of a structure at sub-atomic resolution.

Electrons↗
PubMed2001

Protein structural domain parsing by consensus reasoning over multiple knowledge sources and methods.

Domain parsing, or the detection of signals of protein structural domains from sequence data, is a complex and difficult problem. If carried out reliably it would be a powerful interpretive and predictive tool for genomic and proteomic studies. We report on a novel approach to domain parsing using consensus techniques based on Hidden Markov Models (HMMs) and BLAST searches built from a training set of 1471 continuous structural domains from the Dali Domain Dictionary (DDD). Validation on an independent test sample of family-matched structural domain sequences from the Scop database yields a consensus prediction performance rate of 75.5%, well above the 58% obtained by simple agreement of methods.

Algorithms↗
PubMedDate not supplied

[The glosso-crico-arytenoid unit as a phonatory organ in sub-total reconstructive laryngectomy using the Labayle technic].

The present study was carried out in order to assess characteristics of vicarious voice in patients undergoing Labayle's reconstructive sub-total laryngectomy. This type of surgery, which permits air passage for both respiration and phonation, makes it possible to preserve pneumophonic coordination. During phonation the expiratory air column is used and sound is generated as it passes through a vibrating structure having a sphincteric function. In the opinion of the authors this structure is not only made up of the cricoid orifice, against which the base of the tongue presses like an operculum, but also of the mobile residual arytenoid and, at times, of the lateral walls of the pharynx. Thus a single dynamic unit is formed involving several structures and their synergism guarantees the neoglottic occlusion required for a speaking voice. In the present study, glottography gave no significant results. In phonation a rapid vibration of the neoglottid mucosa is obtained thus producing a phonetically valid acoustic phenomenon. However, this does not result in an electroglottographic recording of adduction. On the other hand, interesting data were recorded when comparing the morpho-functional aspects of the neoglottis with characteristics of the vibrating voice, as recorded by spectrography. Spectrographic tracings are markedly better in cases of valid occlusion of the glosso-pharyngeal-arytenoid unit and this may be achieved regardless of the mobility of the remaining arytenoid. It is thus clear that several patients with a fixed arytenoid, but having valid sphincteric action of the other structures (i.e. base of the tongue or pharynx), had excellent speech quality and intelligibility. Therefore, Labayle's surgery, which reconstructs a pharyngo-tracheal continuity and consequently restores natural breathing, makes speech continuity possible. Such subjects have mixed vocal output (periodic components together with noise) although, on the whole, the voice produced has the fundamental requirements for intelligibility (i.e. intensity, pitch, harmonic structure, emission time) and may thus be considered valid for interpersonal verbal communication.

Arytenoid Cartilage↗
PubMed2003

A new FISH assay to simultaneously detect structural and numerical chromosomal abnormalities in mouse sperm.

De novo aberrations in chromosome structure represent important categories of paternally transmitted genetic damage. Unlike numerical abnormalities, the majority of de novo structural aberrations among human offspring are of paternal origin. We report the development of a three-color fluorescence in situ hybridization (FISH) assay (CT8) to detect mouse sperm carrying structural and numerical chromosomal abnormalities. The CT8 assay uses DNA probes for the centromeric and telomeric regions of chromosome 2, and a probe for the subcentromeric region of chromosome 8. The CT8 assay was used to measure the frequencies of sperm carrying certain structural aberrations involving chromosome 2 (del2ter, dup2ter, del2cen, dup2cen), disomy 2, disomy 8, and sperm diploidy. Analysis of approximately 80,000 sperm from eight B6C3F1 mice revealed an average baseline frequency of 2.5 per 10,000 sperm carrying partial duplications and deletions of chromosome 2. Extrapolated to the entire haploid genome, approximately 0.4% of mouse sperm are estimated to carry structural chromosomal aberrations, which is more than fivefold lower than the spontaneous frequencies of sperm with chromosome structural aberrations in man. We validated the CT8 assay by comparing the frequencies of abnormal segregants in sperm of T(2;14) translocation carriers detected by this assay against those detected by chromosome painting cytogenetic analysis of meiosis II spermatocytes. The CT8 sperm FISH assay is a promising method for detecting structural chromosome aberrations in mouse sperm with widespread applications in genetics, physiology, and genetic toxicology.

Animals↗
PubMed1999

A validity study of the SSAGA--a comparison with the SCAN.

OBJECTIVE: This study examined the concurrent diagnostic validity of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) across alcohol and drug dependencies, major depression, anxiety disorders and ASPD. The Schedule for Clinical Assessment in Neuropsychiatry (SCAN) was selected as the comparison instrument because it arises from a different tradition and uses a different format for its administration. The SCAN has been shown to be valid and applicable cross-culturally. METHOD: Subjects included 38 men and 42 women volunteers from another study and from an outpatient psychiatry clinic. Selected sections of both the SSAGA and the SCAN interviews were administered to all subjects, approximately 1 week apart, in a randomized order. Because the SCAN does not assess Antisocial Personality Disorder (ASPD), the ASPD section of the Structured Clinical Interview for DSM-III-R (SCID) was substituted for this comparison. RESULTS: The Kappa statistic was used to measure concordance between the two instruments. Kappa for alcohol dependence was in the acceptable range (0.63). Kappas were lower for sedative dependence (0.48) and for cannabis dependence (0.53), but higher for cocaine and stimulant dependence (0.85) and for opioid dependence (0.73). Kappa for major depression and the ASPD diagnoses were high (0.71 and 0.70), but slightly lower agreement was found for panic disorder (0.62). Kappa for social phobia was 0.47. CONCLUSION: These data, combined with results from two previous studies which examined reliability, indicate that the SSAGA is a highly reliable and valid instrument for use in studies of a variety of psychiatric disorders, including alcohol and drug dependence.

Adolescent↗
PubMed2005

Comparative modeling of TNFRSF25 (DR3) predicts receptor destabilization by a mutation linked to rheumatoid arthritis.

We constructed a three-dimensional model of TNFRSF25 (death receptor-3; DR3), a tumor necrosis-receptor family member that is expressed on immune cells and on osteoblasts, to determine whether mutations that are linked to rheumatoid arthritis are likely to have effects on receptor function. Since the crystal structure of DR3 is not known, comparative modeling was used, aligning structural elements of the primary sequences of DR3 with TNFs which have been determined by crystallography, substituting the amino acids of the target protein for those in the known structure, introducing necessary deletions or insertions, followed by energy minimization to yield a putative structure. This approach has been validated by studies of other TNF-family receptors. The results show that the DR3 extracellular domain is comprised of four homologous cysteine-rich domains (CRDs), and that a mutation linked to rheumatoid arthritis is in a region critical for structural integrity of ligand-receptor complexes at the end of CRD3. Specifically, the D158G mutation eliminates two hydrogen bonds normally present in a N/D-T-V/D-C consensus motif typically found flanking the last cysteine of each CRD. This may cause aberrations in either T cell function or in response of bone cells to DR3 ligands, which may contribute to pathology in rheumatoid arthritis. Comparison of RA mutants to mutants in other TNFRSF receptors shows that these occur in homologous positions in CRDs, so that this site is proposed to be a 'hot spot' for mutations in TNFRSF family proteins.

Amino Acid Sequence↗
PubMed2006

Theoretical and experimental investigation of morphology and temperature effects on adsorption of organic vapors in single-walled carbon nanotubes.

Hexane adsorption on single-walled carbon nanotube (SWNT) bundles is studied by both simulation and experimentally using a previously developed computer-aided methodology, which employed a smaller physisorbed probe molecule, nitrogen, to explore the porosity of nanotube samples. Configurational-bias grand canonical Monte Carlo simulation of hexane adsorption on localized sites of the bundles is carried out to predict adsorption on their external surface and in their internal sites. These localized isotherms are then combined into a global isotherm for a given sample by using knowledge of its tube-diameter distribution and structural parameters, such as the fraction of open-ended nanotubes and the external surface area of bundles in samples, which have been independently determined from the standard nitrogen adsorption isotherm. The near-perfect replication of experimental isotherms demonstrates the validity of our method for structural characterization of SWNT samples. The effect of temperature on adsorption is also studied and the simulation results are extrapolated to predict the limiting hexane adsorption capacity of the samples. The similarity between the hexane adsorption isotherms and those of other organic molecules demonstrates that the adsorption mechanisms explored here are not specific to hexane, and that the proposed methodology can be potentially applicable to other sorbates with equal success.

Journal Article↗
PubMed2000

Generalizability of the clinical dimensions of the Addiction Severity Index to nonopioid-dependent patients.

Clinical dimensions (CDs) for the Addiction Severity Index recently have been established for application among opioid-dependent patients in methadone treatment (P. A. McDermott et al., 1996). This article examines the generalizability of the CDs to other substance-dependent patients. A sample of 2,027 adult nonopioid-dependent patients was identified; it comprised 581 primarily cocaine-dependent, 544 primarily alcohol-dependent, and 803 polydrug-dependent patients and 99 patients who were dependent on other varied drugs. Generality of dimensions was assessed through confirmatory components analysis, structural congruence, internal consistency, and variance partitioning in higher order factoring. The CDs were found generalizable overall and to specific nonopioid-dependent subgroups, and across patient gender and age, and to African American and White patients. Preliminary concurrent and predictive validity data supported the CD structure.

Adult↗
PubMed1999

A factor analytic study of the dizziness handicap inventory: does it assess phobic avoidance in vestibular referrals?

Panic disorder and agoraphobia have been associated with increased functional disability in individuals who have vestibular problems. The Dizziness Handicap Inventory (DHI), a 25-item self-report questionnaire with three rationally derived subscales, was designed to measure functional, emotional, and physical disability associated with vestibular disturbance. Despite the apparent usefulness of the DHI, there have been few studies of its psychometric properties. The primary purpose of the present study was to assess the factor structure of the DHI. A principal components analysis with oblique rotation was conducted on data collected from 95 patients referred to a tertiary-care vestibular disorders clinic for assessment of vestibular disturbance. Both 2-factor and 3-factor solutions are reported. The 2-factor solution was indicative of General Functional Limitations and Postural Difficulties. In the 3-factor solution, General Functional Limitations was split into factors indicative of Disability in Activities of Daily Living and Phobic Avoidance, while the Postural Difficulties factor remained stable. We also characterized the 3-factor solution by assessing the correlation of factor scores with measures of vestibular symptoms, mood, and anxiety. The general pattern of results does not support the validity of the original subscale structure of the DHI. Implications for revising the DHI to provide a more comprehensive and factorially valid assessment of disability associated with vestibular disturbance are discussed.

Adult↗
PubMed2005

Revealing the multidimensional framework of the Minnesota nicotine withdrawal scale.

OBJECTIVES: The version of the Minnesota Nicotine Withdrawal Scale (MNWS) under consideration consists of nine items. No psychometric analyses of this version have been published. The objectives of this investigation were to perform a factor analysis and to further assess the psychometric properties of the MNWS. RESEARCH DESIGN AND METHODS: Data came from three Phase II clinical trials on varenicline, developed for smoking cessation, in a sample of smokers. Exploratory factor analysis was used to examine the structure of the MNWS in the first completed study (n = 626) over various time periods. The postulated factor structure was then tested in a set of confirmatory analyses conducted on two subsequent studies (n = 627, n = 312). The proposed structure was further evaluated through construct validity and reliability analyses. MAIN OUTCOME MEASURES: The nine items of the MNWS included the following: urge to smoke (craving); depressed mood; irritability, frustration, or anger; anxiety; difficulty concentrating; restlessness; increased appetite; difficulty going to sleep; and difficulty staying asleep. Each item was rated by a subject on an ordinal scale from 0 (not at all) to 4 (extreme). RESULTS: Scree plots and rotated factor patterns from the exploratory factor analyses revealed two multi-item domains--Negative Affect with four items and Insomnia with two items--and three individual items (Craving, Restlessness, Increased Appetite). Confirmatory factor analyses supported the structure with fit indexes exceeding 0.90. The multidimensional framework of the MNWS correlated as expected with health status, depicted an expected course of withdrawal symptoms over time, predicted the sensitivity of withdrawal symptoms on subsequent cessation, and produced internal reliability estimates above 0.70. CONCLUSIONS: Evidence is obtained to support the validity and reliability of the multidimensional structure of the nine-item MNWS. The data suggest that the MNWS has individual constructs on Negative Affect (depressed mood; irritability, frustration, or anger; anxiety; difficulty concentrating), Insomnia (difficulty going to sleep; difficulty staying asleep), Craving, Restlessness, and Increased Appetite. As such, analyzing each construct separately would strengthen the analysis of the popular MNWS.

Adolescent↗
PubMedDate not supplied

Structured skin care regimen to prevent perineal dermatitis in the elderly.

A preliminary investigation was conducted to determine the efficacy of a structured skin care regimen to prevent perineal dermatitis in incontinent geriatric psychiatry patients. A 10-week, prospective, clinical trial was conducted (n = 15). Four weeks (weeks 2 to 5) were devoted to monitoring the unstructured pretreatment nursing skin care practice and to determining the incidence of perineal dermatitis in incontinent patients. Four weeks (weeks 7 to 10) were also spent implementing and observing the structured nursing skin care regimen. The study revealed that 33% (three) of the subjects in the unstructured skin care group and 33% (two) of the subjects in the structured skin care group had perineal dermatitis. In subjects with a combination of urine and stool incontinence perineal dermatitis developed within 2 days. The findings suggest that perineal dermatitis occurs quickly in the presence of urine and stool incontinence. Further research is needed to validate the efficacy of a structured skin care regimen to prevent perineal dermatitis.

Aged↗