322 research outputs found

    Several functional equations defined on groups arising from stochastic distance measures.

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    Several functional equations related to stochastic distance measures have been widely studied when defined on the real line. This dissertation generalizes several of those results to functions defined on groups and fields. Specifically, we consider when the domain is an arbitrary group, G, and the range is the field of complex numbers, C. We begin by looking at the linear functional equation f(pr, qs)+f(ps, qr) = 2f(p, q)+2f(r, s) for all p, q, r, s, € G. The general solution f : G x G → C is given along with a few specific examples. Several generalizations of this equation are also considered and used to determine the general solution f, g, h, k : G x G → C of the functional equation f(pr, qs) + g(ps, qr) = h(p, q) + k(r, s) for all p, q, r, s € G. We then consider the non-linear functional equation f(pr, qs) + f(ps, qr) = f(p, q) f(r, s). The solution f : G x G → C is given for all p, q, r, s € G when f is an abelian function. It is followed by the structure of the general solution, f, dependent upon how the function acts on the center of the group. Several generalizations of the equation are also considered. The general structure of the solution f, g, h : G x G → C of the functional equation f(pr, qs) + f(ps, qr) = g(p, q) h(r, s) is given for all p, q, r, s € G, dependent upon how the function h acts on the center of the group. Future plans related to these equations will be given

    Effects of comorbid anxiety disorders on the longitudinal course of pediatric bipolar disorders

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    OBJECTIVE: To examine the longitudinal effects of comorbid anxiety disorders in youth with bipolar spectrum disorder (BP). METHOD: As part of the Course and Outcome of Bipolar Youth study, 413 youth, who were 7 through 17 years or age and who met criteria for DSM-IV BP-I (n = 244), BP-II (n = 28), and operationally defined bipolar disorder not otherwise specified (BP-NOS) (n = 141) were included. Subjects were followed on average 5 years using the Longitudinal Interval Follow-up Evaluation. Effects of anxiety on the time to mood recovery and recurrence and percentage of time with syndromal and subsyndromal mood symptomatology during the follow-up period were analyzed. RESULTS: At intake and during the follow-up, 62% of youth with BP met criteria for at least 1 anxiety disorder. About 50% of the BP youth with anxiety had ≥2 anxiety disorders. Compared to BP youth without anxiety, those with anxiety had significantly more depressive recurrences and significantly longer median time to recovery. The effects of anxiety on recovery disappeared when the severity of depression at intake was taken into account. After adjusting for confounding factors, BP youth with anxiety, particularly those with ≥2 anxiety disorders, spent significantly less follow-up time asymptomatic and more time with syndromal mixed/cycling and subsyndromal depressive symptomatology compared to those without anxiety. CONCLUSIONS: Anxiety disorders are common and adversely affect the course of BP in youth, as characterized by more mood recurrences, longer time to recovery, less time euthymic, and more time in mixed/cycling and depressive episodes. Prompt recognition and the development of treatments for BP youth with anxiety are warranted

    Cognitive flexibility and performance in children and adolescents with threshold and sub-threshold bipolar disorder

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    Greater understanding of cognitive function in children and adolescents with bipolar disorder (BD) is of critical importance to improve our ability to design targeted treatments to help with real-world impairment, including academic performance. We sought to evaluate cognitive performance among children with either BD type I, II, or “not otherwise specified” (NOS) participating in multi-site Course and Outcome of Bipolar Youth study compared to typically developing controls (TDC) without psycho-pathology. In particular, we sought to test the hypothesis that BD-I and BD-II youths with full threshold episodes of mania or hypomania would have cognitive deficits, including in reversal learning, vs. those BD-NOS participants with sub-threshold episodes and TDCs. N = 175 participants (BD-I = 81, BD-II = 11, BD-NOS = 28, TDC = 55) completed Cambridge Neuropsychological Automated Testing Battery (CANTAB) tasks. A priori analyses of the simple reversal stage of the CANTAB intra-/extra-dimensional shift task showed that aggregated BD-I/II participants required significantly more trials to complete the task than either BD-NOS participants with sub-syndromal manic/hypomanic symptoms or than TDCs. BD participants across sub-types had impairments in sustained attention and information processing for emotionally valenced words. Our results align with prior findings showing that BD-I/II youths with distinct episodes have specific alterations in reversal learning. More broadly, our study suggests that further work is necessary to see the interaction between neurocognitive performance and longitudinal illness course. Additional work is required to identify the neural underpinnings of these differences as targets for potential novel treatments, such as cognitive remediation

    The images of psychiatry scale: development, factor structure, and reliability.

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    BACKGROUND: This analysis is based on a survey questionnaire designed to describe medical educators' views of psychiatry and psychiatrists. Our goals in this paper were to assess the psychometric properties of the survey questions by (a) using exploratory factor analysis to identify the basic factor structure underlying 37 survey items; (b) testing the resulting factor structure using confirmatory factor analysis; and (c) assessing the internal reliability of each identified factor. To our knowledge, this is the first attempt to use these techniques to psychometrically assess a scale measuring the strength of stigma that medical educators attached to psychiatry. METHODS: Survey data were collected from a random sample of 1,059 teaching faculty in 23 academic teaching sites in 15 countries. We conducted exploratory and confirmatory factor analysis to identify the scale structure and Cronbach's alpha to assess internal consistency of the resulting scales. RESULTS: Results showed that a two-factor solution was the best fit for the data. Following exploratory factor analysis, we conducted confirmatory factor analysis on a split half of the sample. Results highlighted several items with low loadings. Excluding factors with low correlations and allowing for several correlated variances resulted in a good fitting model explaining 95% of the variance in the data. CONCLUSIONS: We identified two unidimensional scales. The Images Scale contained 11 items measuring stereotypic content concerning psychiatry and psychiatrists. The Efficacy of Psychiatry Scale contained 5 items addressing perceptions of the challenges and effectiveness of psychiatry as a discipline

    Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status

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    Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research

    How European Fans in Training (EuroFIT), a lifestyle change program for men delivered in football clubs, achieved its effect : a mixed methods process evaluation embedded in a randomised controlled trial

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    Funding This project has received funding from the European Union’s Seventh Framework Program for research, technological development, and demonstration under grant agreement number 602170. The Health Services Research Unit, University of Aberdeen, receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgements We are grateful to participants who took part in the research, coaches and club managers at fifteen football clubs and UEFA’s Football and Social Responsibility department for supporting the proposal at bidding stage. Ciaran Clissman of Pintail Ltd managed the project and provided invaluable editorial input into the funding application and delivery of the program. Prof Nanette Mutrie was substantially involved in the development of the EuroFIT program. Dr Lisa Macauley administered the UK data collection in the UK and Alan Pollok supported some UK data collection. Dr Mattias Rost and Prof Mathew Chalmers were substantially involved in the development of MatchFIT and Drs Douglas Maxwell and Nikos Mourselas of PAL Technologies in the technical development of the SitFIT. Views and opinions expressed are those of the authors and do not necessarily reflect those of the European Union.Peer reviewedPublisher PD

    Longitudinal Associations Between Interpersonal Relationship Functioning and Mood Episode Severity in Youth With Bipolar Disorder

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    This study examined the longitudinal association between mood episode severity and relationships in BP youth. Participants were 413 Course and Outcome of Bipolar Youth study youth, aged 12.6 ± 3.3 years. Monthly ratings of relationships (parents, siblings, and friends) and mood episode severity were assessed by the Adolescent Longitudinal Interval Follow-Up Evaluation (ALIFE) Psychosocial Functioning Schedule (PFS) and Psychiatric Rating Scales (PSR) on average every 8.2 months over 5.1 years. Correlations examined whether participants with increased episode severity also reported poorer relationships, and also examined whether fluctuations in episode severity predicted fluctuations in relationships, and vice versa. Results indicated that participants with greater mood episode severity also had worse relationships. Longitudinally, participants had largely stable relationships. To the extent that there were associations, changes in parental relationships may precede changes in episode severity, although the magnitude of this finding was small. Findings have implications for relationship interventions in BP youth

    Is there an association between seeing incidents of alcohol or drug use in films and young Scottish adults' own alcohol or drug use? A cross sectional study

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    <p>Background: As the promotion of alcohol and tobacco to young people through direct advertising has become increasingly restricted, there has been greater interest in whether images of certain behaviours in films are associated with uptake of those behaviours in young people. Associations have been reported between exposure to smoking images in films and smoking initiation, and between exposure to film alcohol images and initiation of alcohol consumption, in younger adolescents in the USA and Germany. To date no studies have reported on film images of recreational drug use and young people's own drug use.</p> <p>Methods: Cross sectional multivariable logistic regression analysis of data collected at age 19 (2002-4) from a cohort of young people (502 boys, 500 girls) previously surveyed at ages 11 (in 1994-5), 13 and 15 in schools in the West of Scotland. Outcome measures at age 19 were: exceeding the 'sensible drinking' guidelines ('heavy drinkers') and binge drinking (based on alcohol consumption reported in last week), and ever use of cannabis and of 'hard' drugs. The principle predictor variables were an estimate of exposure to images of alcohol, and of drug use, in films, controlling for factors related to the uptake of substance use in young people.</p> <p>Results: A third of these young adults (33%) were classed as 'heavy drinkers' and half (47%) as 'binge drinkers' on the basis of their previous week's consumption. Over half (56%) reported ever use of cannabis and 13% ever use of one or more of the 'hard' drugs listed. There were linear trends in the percentage of heavy drinkers (p = .018) and binge drinkers (p = 0.012) by film alcohol exposure quartiles, and for ever use of cannabis by film drug exposure (p = .000), and for ever use of 'hard' drugs (p = .033). The odds ratios for heavy drinking (1.56, 95% CI 1.06-2.29 comparing highest with lowest quartile of film alcohol exposure) and binge drinking (1.59, 95% CI 1.10-2.30) were attenuated by adjustment for gender, social class, family background (parental structure, parental care and parental control), attitudes to risk-taking and rule-breaking, and qualifications (OR heavy drinking 1.42, 95% CI 0.95-2.13 and binge drinking 1.49, 95% CI 1.01-2.19), and further so when adjusting for friends' drinking status (when the odds ratios were no longer significant). A similar pattern was seen for ever use of cannabis and 'hard' drugs (unadjusted OR 1.80, 95% CI 1.24-2.62 and 1.57, 95% CI 0.91-2.69 respectively, 'fully' adjusted OR 1.41 (0.90-2.22 and 1.28 (0.66-2.47) respectively).</p> <p>Conclusions: Despite some limitations, which are discussed, these cross-sectional results add to a body of work which suggests that it is important to design good longitudinal studies which can determine whether exposure to images of potentially health-damaging behaviours lead to uptake of these behaviours during adolescence and early adulthood, and to examine factors that might mediate this relationship.</p&gt
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