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PubMed2000

Convergent validity of the tinnitus handicap inventory and the tinnitus questionnaire.

For research into tinnitus to be robust and credible, the use of well-validated instruments of self-perceived tinnitus handicap as outcome measures is essential. The tinnitus handicap inventory (THI) and the tinnitus questionnaire (TQ) are two such instruments which are in widespread use. Both questionnaires were administered by mail to 100 consecutive new patients of the Cambridge Tinnitus Clinic, and completed in randomized order. These patients had been referred by the otolaryngology team and had not undergone any tinnitus therapy. The response rate was 78 per cent, neither questionnaire being more acceptable to patients than the other. The convergent validity of the instruments was high, with total and subscale scores all being significantly correlated at the five per cent level (Spearman correlation coefficients). A number of subscale scores were not significantly correlated at the one per cent level however. In particular, the sleep disturbance element of the TQ was demonstrated to have some discriminant validity from the THI and from other elements of the TQ at the one per cent significance level. The THI and TQ have been demonstrated to have high convergent validity and are both suitable for tinnitus outcome studies involving the quantification of self-perceived tinnitus handicap. For research that aims to determine the specific effect of an intervention on tinnitus-related sleep disturbance, the TQ sleep subscale has potential utility. The hypothetical constructs of tinnitus handicap underlying the psychologist-developed TQ and the audiologist-developed THI have been shown to be convergent.

Adolescent↗

PubMed2003

Converging paradigms for environmental health theory and practice.

Converging themes from the fields of environmental health, ecology and health, and human ecology highlight opportunities for innovation and advancement in environmental health theory and practice. In this commentary we outline the role of research and applied programs that integrate biophysical and social sciences with environmental health practice in order to address deficiencies in each field when taken on its own. New opportunities for environmental health protection and promotion are outlined based on the three converging themes: integrated approaches to research and policy, methodological acknowledgment of the synergies between the social and biophysical environments, and incorporation of core ecosystem principles into research and practice. These converging themes are discussed in relation to their implications for new types of intervention to achieve health gains across different spatial and temporal scales at the interface between biophysical and social environments.

Biophysical Phenomena↗

PubMed2004

Convergence in mean square of factor predictors.

Sufficient conditions for mean square convergence of factor predictors in common factor analysis are given by Guttman, by Williams, and by Schneeweiss and Mathes. These conditions do not hold for confirmatory factor analysis or when an error variance equals zero (Heywood cases). Two sufficient conditions are given for the three basic factor predictors and a predictor from rotated principal components analysis to converge to the factors of the model for confirmatory factor analysis, including Heywood cases. For certain model specifications the conditions are necessary. The conditions are sufficient for the existence of a unique true factor. A geometric interpretation is given for factor indeterminacy and mean square convergence of best linear factor prediction.

Factor Analysis, Statistical↗

PubMed2002

Convergent optical correlator aligment based on frequency filtering.

The convergent correlator is widely used but it presents the drawback of the alignment requirements: fine focusing of the input scene Fourier transform on the filter plane, filter centering, scaling the scene Fourier transform to match the filter size, and azimuth matching of the filter with the input scene. We propose a set of tests to obtain a precise alignment of the convergent correlator. These methods are based on frequency filtering properties and they are applicable either for amplitude input or for phase-encoded input. The tests we present allow us to fulfill all the alignment requirements. The theory on which these tests are based is explained. The experimental results obtained during the alignment procedure are presented. We show some additional verifications of the correct alignment of the convergent correlator.

Journal Article↗

PubMed2006

Convergence of the discrete dipole approximation. I. Theoretical analysis.

We perform a rigorous theoretical convergence analysis of the discrete dipole approximation (DDA). We prove that errors in any measured quantity are bounded by a sum of a linear term and a quadratic term in the size of a dipole d when the latter is in the range of DDA applicability. Moreover, the linear term is significantly smaller for cubically than for noncubically shaped scatterers. Therefore, for small d, errors for cubically shaped particles are much smaller than for noncubically shaped ones. The relative importance of the linear term decreases with increasing size; hence convergence of DDA for large enough scatterers is quadratic in the common range of d. Extensive numerical simulations are carried out for a wide range of d. Finally, we discuss a number of new developments in DDA and their consequences for convergence.

Journal Article↗

PubMed2004

Evidence for widespread convergent evolution around human microsatellites.

Microsatellites are a major component of the human genome, and their evolution has been much studied. However, the evolution of microsatellite flanking sequences has received less attention, with reports of both high and low mutation rates and of a tendency for microsatellites to cluster. From the human genome we generated a database of many thousands of (AC)(n) flanking sequences within which we searched for common characteristics. Sequences flanking microsatellites of similar length show remarkable levels of convergent evolution, indicating shared mutational biases. These biases extend 25-50 bases either side of the microsatellite and may therefore affect more than 30% of the entire genome. To explore the extent and absolute strength of these effects, we quantified the observed convergence. We also compared homologous human and chimpanzee loci to look for evidence of changes in mutation rate around microsatellites. Most models of DNA sequence evolution assume that mutations are independent and occur randomly. Allowances may be made for sites mutating at different rates and for general mutation biases such as the faster rate of transitions over transversions. Our analysis suggests that these models may be inadequate, in that proximity to even very short microsatellites may alter the rate and distribution of mutations that occur. The elevated local mutation rate combined with sequence convergence, both of which we find evidence for, also provide a possible resolution for the apparently contradictory inferences of mutation rates in microsatellite flanking sequences.

Base Sequence↗

PubMed2006

Genomic convergence toward diploidy in Saccharomyces cerevisiae.

Genome size, a fundamental aspect of any organism, is subject to a variety of mutational and selection pressures. We investigated genome size evolution in haploid, diploid, and tetraploid initially isogenic lines of the yeast Saccharomyces cerevisiae. Over the course of approximately 1,800 generations of mitotic division, we observed convergence toward diploid DNA content in all replicate lines. This convergence was observed in both unstressful and stressful environments, although the rate of convergence was dependent on initial ploidy and evolutionary environment. Comparative genomic hybridization with microarrays revealed nearly euploid DNA content by the end of the experiment. As the vegetative life cycle of S. cerevisiae is predominantly diploid, this experiment provides evidence that genome size evolution is constrained, with selection favouring the genomic content typical of the yeast's evolutionary past.

Chromosomes, Fungal↗

PubMed2005

The convergence of the regional twinning rates in Sweden, 1751-1960.

Sweden has, as a whole nation, the oldest continuous population register of births, including twin and higher multiple maternities, starting in the 17th century. Until the 1920s, the rates of multiple maternities in Sweden were among the highest known among Europeans. Strong secular and regional fluctuations were noted. Some of the eastern counties showed especially marked decreasing trends. The twinning rate had no clear associations with the anthropometric and serological data. In this paper we study the temporal and regional variations of the twinning rate in the 25 counties of Sweden from 1751 to 1960. Different statistical methods were applied in order to test the hypothesis that, irrespective of the initial levels, the twinning rates for the counties converge towards a common low level. We present and interpret a geometrical model for the trends of the regional twinning rates. We also analyze the regional heterogeneity using the ranges and the coefficients of variation of the regional twinning rates. All the methods gave consistent results, supporting our convergence hypothesis that the regional differences in the twinning rate are gradually disappearing. In addition, this study supports our earlier findings that the regional heterogeneity cannot be explained by differences in the distribution of maternal age and parity. We suggest that the convergence may be caused by increased urbanization and industrialization and by the increased interregional migration of citizens as a consequence of better communications, which lead to the breaking up of isolates and decreased endogamy.

Birth Rate↗

PubMed2006

Molecular profiling of antipsychotic drug function: convergent mechanisms in the pathology and treatment of psychiatric disorders.

Despite great progress in antipsychotic drug research, the molecular mechanisms by which these drugs work have remained elusive. High-throughput gene profiling methods have advanced this field by allowing the simultaneous investigation of hundreds to thousands of genes. However, different methodologies, choice of brain region, and drugs studied have made comparisons across different studies difficult. Because of the complexity of gene expression changes caused by drugs, teasing out the most relevant expression differences is a challenging task. One approach is to focus on gene expression changes that converge on the same systems that were previously deemed important to the pathology of psychiatric disorders. From the microarray studies performed on human postmortem brain samples from schizophrenics, the systems most implicated to be dysfunctional are synaptic machinery, oligodendrocyte/myelin function, and mitochondrial/ubiquitin metabolism. Drugs may act directly or indirectly to compensate for underlying pathological deficits in schizophrenia or via other mechanisms that converge on these pathways. Side effects, consisting of motor and metabolic dysfunction (which occur with typical and atypical drugs, respectively), also may be mediated by gene expression changes that have been reported in these studies. This article surveys both the convergent antipsychotic mechanisms and the genes that may be responsible for other effects elicited by antipsychotic drugs.

Animals↗

PubMed2004

Convergent and discriminative validity of interview and questionnaire measures of personality disorder in mentally disordered offenders: a multitrait-multimethod analysis using confirmatory factor analysis.

Measures of personality disorder from the International Personality Disorder Examination, Personality Diagnostic Questionnaire, and Millon Clinical Multiaxial Inventory (MCMI-II) were obtained from detained male mentally disordered offenders (N = 156), and convergent and discriminant validity were examined by confirmatory factor analysis of the multitrait-multimethod matrix. Hierarchical comparisons of models varying in their specification of trait and method variance established the appropriateness of a model supporting both convergence and discrimination across methods, but these were variable across constructs and measures. Convergence was good for avoidant, schizoid, and antisocial disorders, but poor for histrionic, narcissistic, and obsessive-compulsive disorders. Avoidant, schizoid, and schizotypal disorders were not clearly distinguishable from each other. Measurement error attributable to method variance was substantial for all instruments and for most disorders. The commonly alleged superiority of interview over questionnaire methods was not supported, and the MCMI-II demonstrated proportionately more "true" variance. However, assessment methods may be differentially sensitive to different kinds of personality disorder problems.

Adult↗

PubMed2006

Convergence and divergence among self-report psychopathy measures: a personality-based approach.

The study examined, in a sample of 346 undergraduates, the convergence and divergence of three self-report measures of psychopathy; the Psychopathic Personality Inventory (Lillienfeld & Andrews, 1996), the Self-Report Psychopathy scale (Hare, Harpur, & Hemphill, 1989), and the Five Factor Psychopathy Index (Miller, Lynam, Widiger, & Leukefeld, 2001). Measures demonstrated strong convergence at the total score level, but weak convergence at the factor level. Correlations with domains and facets of the NEO Personality Inventory-Revised (Costa & McCrae, 1992) provided personality parsings of each measure. Across measures, psychopathy was composed of low Agreeableness, low Conscientiousness and a blend of high and low facets of Neuroticism and Extraversion. Divergence among subscales was due to differences in personality characteristics assessed. Additionally, the potential moderating effects of sex were also examined, but very few were identified. Implications of these results and future directions are discussed.

Adult↗

PubMed2006

Converging language streams in the human temporal lobe.

There is general agreement that, after initial processing in unimodal sensory cortex, the processing pathways for spoken and written language converge to access verbal meaning. However, the existing literature provides conflicting accounts of the cortical location of this convergence. Most aphasic stroke studies localize verbal comprehension to posterior temporal and inferior parietal cortex (Wernicke's area), whereas evidence from focal cortical neurodegenerative syndromes instead implicates anterior temporal cortex. Previous functional imaging studies in normal subjects have failed to reconcile these opposing positions. Using a functional imaging paradigm in normal subjects that used spoken and written narratives and multiple baselines, we demonstrated common activation during implicit comprehension of spoken and written language in inferior and lateral regions of the left anterior temporal cortex and at the junction of temporal, occipital, and parietal cortex. These results indicate that verbal comprehension uses unimodal processing streams that converge in both anterior and posterior heteromodal cortical regions in the left temporal lobe.

Adult↗

PubMed2006

Ensemble-based convergence analysis of biomolecular trajectories.

Assessing the convergence of a biomolecular simulation is an essential part of any careful computational investigation, because many fundamental aspects of molecular behavior depend on the relative populations of different conformers. Here we present a physically intuitive method to self-consistently assess the convergence of trajectories generated by molecular dynamics and related methods. Our approach reports directly and systematically on the structural diversity of a simulation trajectory. Straightforward clustering and classification steps are the key ingredients, allowing the approach to be trivially applied to systems of any size. Our initial study on met-enkephalin strongly suggests that even fairly long trajectories (approximately 50 ns) may not be converged for this small--but highly flexible--system.

Biopolymers↗

PubMed2003

Convergence and coevolution in a mutualism: evidence from a molecular phylogeny of Ficus.

The interaction between Ficus (Moraceae) and their pollinating wasps (Chalcidoidea: Agaonidae; more than 700 species-specific couples) is one of the most specialized mutualisms found in nature. Both partners of this interaction show extensive variation in their respective biology. Here we investigate Ficus life-history trait evolution and fig/fig wasp coadaptation in the context of a well-resolved molecular phylogeny. Mapping out variations in Ficus life-history traits on an independently derived phylogeny constructed from ribosomal DNA sequences (external and internal transcribed spacer) reveals several parallel transitions in Ficus growth habit and breeding system. Convergent trait evolution might explain the discrepancies between morphological analyses and our molecular reconstruction of the genus. Morphological characters probably correlate with growth habit and breeding system and could therefore be subject to convergent evolution. Furthermore, we reconstruct the evolution of Ficus inflorescence characters that are considered adaptations to the pollinators. Our phylogeny reveals convergences in ostiole shape, stigma morphology, and stamen:ovule ratio. Statistical tests taking into account the phylogenetic relationship of the species show that transitions in ostiole shape are correlated with variation in wasp pollinator head shape, and evolutionary changes in stigma morphology and stamen:ovule ratio correlate with changes in the pollination behavior of the associated wasp. These correlations provide evidence for reciprocal adaptations of morphological characters between these mutualistic partners that have interacted over a long evolutionary time. In light of previous ecological studies on mutualism, we discuss the adaptive significance of these correlations and what they can tell us about the coevolutionary process occurring between figs and their pollinators.

Adaptation, Biological↗

PubMed1996

Axial wall convergence of full veneer crown preparations. Documented for dental students and general practitioners.

The convergence angle in 478 full crown preparations was assessed. Of these preparations, 351 had been performed by general practitioners and 127 by dental students. Groups of preparations performed on incisors, premolars, and molars were compared, as were preparations performed by dentists and students. Two different convergence angles were measured for each tooth, buccolingually and mesiodistally. The results showed a mean angle of 21 degrees. The mean values for premolars and molars differed significantly. When a comparison was made of preparations performed by students, a significant difference was found between premolars and molars. The same comparison for general practitioners showed a significant difference both for incisors compared with molars and for premolars compared with molars. A wide range was found for the convergence of the axial walls, especially for the preparations performed by general practitioners.

Clinical Competence↗

PubMed1984

Sex differences in the use of alcohol and tranquilizers: testing a role convergence hypothesis.

Research on adult alcohol and tranquilizer use provides strong evidence of fundamental sex differences in the use of the two types of drugs. Current explanations posited for these differences center around differential sex roles and sex role expectations. Much of the discussion of these differences suggests that as male and female roles converge, these behavioral differences should decrease. Using data from a statewide survey of Illinois adults, we provide a preliminary test of a sex role convergence hypothesis for alcohol and tranquilizer use. To do so, we use a multinomial extension of logistic multiple regression. After controlling for demographic and sex role characteristics, the results show that females have a much higher probability of using tranquilizers rather than alcohol than men do. Thus, the role convergence hypothesis is not supported for the use of these two types of drugs.

Adolescent↗

PubMed2026

Integrated multi-omics profiling identifies aging-related molecular signatures and convergent interferon signaling in systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is characterized by chronic immune activation and molecular alterations that overlap with aging-related biological processes. However, how these alterations are organized across molecular layers and whether they converge on shared regulatory networks remain incompletely understood. METHODS: We performed an integrative multi-omics analysis combining in-house proteomic and phosphoproteomic data from 130 patients with SLE and 90 healthy controls (HCs) and publicly available transcriptomic datasets comprising 1,461 SLE patients. Proteins and phosphorylation sites were annotated using established aging-related gene resources. Differential protein abundance and phosphorylation changes were analyzed across disease-status and disease-activity comparisons. Nominal P-value thresholds were used for exploratory feature selection, whereas FDR-adjusted P values were used to assess robustness after multiple-testing correction. Kinase-substrate enrichment, transcription factor annotation, and cell-type-resolved transcriptomic comparison were used to explore potential regulatory programs. RESULTS: We identified 128 nominally altered proteins annotated to aging-related biological processes, including genomic instability, mitochondrial dysfunction, and epigenetic alterations. Phosphoproteomic analysis revealed 36 nominally altered phosphorylation sites, including previously unreported sites in IFI16 (S153, S780) and PKCδ (S507, S664). Clustering analysis demonstrated heterogeneous protein co-regulation patterns across disease states. Kinase activity inference suggested altered activity of TBK1 and IKKβ. TF analysis further highlighted STAT1, RELA, and PML as potential central nodes within the inferred regulatory network. Notably, these multi-omic alterations were not randomly distributed but showed convergence toward shared signaling pathways, particularly those related to interferon responses. CONCLUSIONS: This integrative multi-omics study identifies inflammatory and interferon-dominated molecular alterations in SLE PBMCs that overlap with aging-related biological processes and converge on shared regulatory networks. These findings provide a hypothesis-generating framework for investigating the intersection between chronic immune activation and aging-related molecular remodeling in SLE.

Humans↗

PubMed2005

The convergent validity of the Manchester Pain Scale.

OBJECTIVE: To test the convergent validity of the Manchester pain scale when compared to the current 'gold standard' in children's pain assessment, the Oucher pain scale. METHOD: One hundred and fifty two children presenting to the emergency department had pain scale assessments using both the Manchester and Oucher pain scales. The order of presentation of the scales was randomised. The degree of convergence between the scales was assessed using Spearman's rank correlation as well as Bland and Altman plots. RESULTS: One hundred and thirteen children used numerical scales; the correlation coefficient for these was 0.802. Thirty nine children used pictorial scales; the correlation coefficient was 0.820. CONCLUSION: There is strong convergent validity between the scales as demonstrated by a high degree of correlation between the numerical and pictorial scores generated by the Manchester and Oucher pain scales. The Manchester pain scale can be used to assess pain in children presenting to emergency departments.

Adolescent↗