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Search Results: 1 - 10 of 1931 matches for " Tony Cassidy "
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Family Background and Environment, Psychological Distress, and Juvenile Delinquency  [PDF]
Tony Cassidy
Psychology (PSYCH) , 2011, DOI: 10.4236/psych.2011.29142
Abstract: The relationship between youth offending and family background is still unclear in the literature. This study explored the role of family factors and psychological distress in relation to delinquency and youth offending to try and explicate the relative importance of family structure, family relations, and psychological distress. The study used the Brief Symptom Inventory, the Family Environment Scale, and the Delinquency Scale in a structured interview format to measure psychological distress, family structure and relations, and levels of youth offending, in 219 older children and adolescents aged between 12-17 years living in areas associated with high levels of youth offending in the UK. Analysis involved correlations, hierarchical multiple regression and analysis of variance. Family relations were the best predictors of delinquency and were also correlated with psychological distress. The relationship between delinquency and psychological distress indicated that participants with more psychological distress were less likely to be involved in criminal behaviour. The study supports the conclusion that youth offending and psychological distress are both influenced by a range of factors in the family, but may be unrelated to each other.
Family Structure and Psychological Health in Young Adults  [PDF]
Tony Cassidy, Elizabeth Wright, Elizabeth Noon
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.510129
Abstract:

This study explored the effect of the gendered structure of siblings in intact and non-intact families, on family relations, social support, perceived control, and psychological distress in a sample of 708 young adults (294 males and 414 females) aged between 18 - 21 years. Of the sample 96 were singletons, 208 had both a brother and sister, 206 had a brother and no sister, and 198 had a sister and no brother. While the results show that both the gender of the participants and the gender of the sibling seem to impact on distress and its mediators; the more important factor is the gender of siblings. In essence the presence of a female sibling is associated with more perceived support, control and optimism, and with lower pessimism and psychological distress. The presence of a female is also associated with better family relations overall and it is suggested that the main mechanism for this positive impact of female siblings is through the lowered conflict and increased expressiveness and cohesion experienced in female versus male dominated sibling groups.

Perceptions of Coach Social Identity and Team Confidence, Motivation and Self-Esteem  [PDF]
Tony Cassidy, Paul Cummins, Gavin Breslin, Maurice Stringer
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.510130
Abstract:

The social identity theory of leadership has potential application to sport coaching research but lacks a usable measure. We administered a pool of 51 items to 271 sport science students aiming to produce measures of coach prototypicality and team identity. Principal component analysis (PCA) produced a 10-item Coach Social Identity Scale (CSIS), and a 15-item Team Social Identity Scale (TSIS). The study produced initial evidence of reliability and validity for both the CSIS and the TSIS, providing a potentially useful set of measures with which to explore the role of social identity in coaching.

Prognosis of patients with whiplash-associated disorders consulting physiotherapy: development of a predictive model for recovery
Bohman Tony,C?té Pierre,Boyle Eleanor,Cassidy J David
BMC Musculoskeletal Disorders , 2012, DOI: 10.1186/1471-2474-13-264
Abstract: Background Patients with whiplash-associated disorders (WAD) have a generally favourable prognosis, yet some develop longstanding pain and disability. Predicting who will recover from WAD shortly after a traffic collision is very challenging for health care providers such as physical therapists. Therefore, we aimed to develop a prediction model for the recovery of WAD in a cohort of patients who consulted physical therapists within six weeks after the injury. Methods Our cohort included 680 adult patients with WAD who were injured in Saskatchewan, Canada, between 1997 and 1999. All patients had consulted a physical therapist as a result of the injury. Baseline prognostic factors were collected from an injury questionnaire administered by Saskatchewan Government Insurance. The outcome, global self-perceived recovery, was assessed by telephone interviews six weeks, three and six months later. Twenty-five possible baseline prognostic factors were considered in the analyses. A prediction model was built using Cox regression. The predictive ability of the model was estimated with concordance statistics (c-index). Internal validity was checked using bootstrapping. Results Our final prediction model included: age, number of days to reporting the collision, neck pain intensity, low back pain intensity, pain other than neck and back pain, headache before collision and recovery expectations. The model had an acceptable level of predictive ability with a c-index of 0.68 (95% CI: 0.65, 0.71). Internal validation showed that our model was robust and had a good fit. Conclusions We developed a model predicting recovery from WAD, in a cohort of patients who consulted physical therapists. Our model has adequate predictive ability. However, to be fully incorporated in clinical practice the model needs to be validated in other populations and tested in clinical settings.
Effective Truncation of a Student’s t-Distribution by Truncation of the Chi Distribution in a Chi-Normal Mixture  [PDF]
Daniel T. Cassidy
Open Journal of Statistics (OJS) , 2012, DOI: 10.4236/ojs.2012.25067
Abstract: A Student’s t-distribution is obtained from a weighted average over the standard deviation of a normal distribution, σ, when 1/σ is distributed as chi. Left truncation at q of the chi distribution in the mixing integral leads to an effectively truncated Student’s t-distribution with tails that decay as exp (-q2t2). The effect of truncation of the chi distribution in a chi-normal mixture is investigated and expressions for the pdf, the variance, and the kurtosis of the t-like distribution that arises from the mixture of a left-truncated chi and a normal distribution are given for selected degrees of freedom <5. This work has value in pricing financial assets, in understanding the Student’s t--distribution, in statistical inference, and in analysis of data.
Suicide, Mental Illness and Maori People  [PDF]
Said Shahtahmasebi, Bernadette Cassidy
Open Journal of Social Sciences (JSS) , 2014, DOI: 10.4236/jss.2014.28014
Abstract: Globally, authorities and “experts” continually assert that suicide is a major public health concern and it is preventable. However, decades of suicide prevention strategies have seen “more of the same” action plans but no change in the upward suicide trend. Therefore, the current suicide prevention model is less relevant to indigenous and minority populations with a high suicide rate. Current suicide statistics for Maori, New Zealand’s indigenous population are unacceptably high. The Maori suicide rate is about 19 per 100,000 roughly averaging about 104 deaths per year over the last six years. Maori claim that before colonisation suicide was non-existent. There is certainly evidence to support such a claim. e.g., historical suicide data suggested that the number of Maori youth suicide deaths was less than five until the 1970s and 1980s. Maori now have the dubious honour of having the highest rates of mortality and morbidity outcomes, including higher rates of suicide. Neither Maori nor the authorities responded with an action plan when suicide numbers spiked in 1960 and 1967. Subsequently, the number of suicides rose sharply to over one hundred where they stayed. It is plausible that exposure to Western ideals as well as social insensitivity to Maori beliefs and needs may have led to a cultural dealignment during the1960s and 1970s. This cultural shift also may be due to the application of a Western model of suicide prevention based on mental illness. The Western model does not work in preventing suicide and conflicts with indigenous cultures.
How Far Can a Biased Random Walker Go?  [PDF]
Zhongjin Yang, Cassidy Yang
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.39143
Abstract: The random walk (RW) is a very important model in science and engineering researches. It has been studied over hundreds years. However, there are still some overlooked problems on the RW. Here, we study the mean absolute distance of an N-step biased random walk (BRW) in a d-dimensional hyper-cubic lattice. In this short paper, we report the exact results for d = 1 and approximation formulae for d ≥ 2.
Student’s t Increments  [PDF]
Daniel T. Cassidy
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.61014
Abstract: Some moments and limiting properties of independent Student’s t increments are studied. Inde-pendent Student’s t increments are independent draws from not-truncated, truncated, and effectively truncated Student’s t-distributions with shape parameters and can be used to create random walks. It is found that sample paths created from truncated and effectively truncated Student’s t-distributions are continuous. Sample paths for Student’s t-distributions are also continuous. Student’s ?t increments should thus be useful in construction of stochastic processes and as noise driving terms in Langevin equations.
A Multivariate Student’s t-Distribution  [PDF]
Daniel T. Cassidy
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.63040
Abstract: A multivariate Student’s t-distribution is derived by analogy to the derivation of a multivariate normal (Gaussian) probability density function. This multivariate Student’s t-distribution can have different shape parameters for the marginal probability density functions of the multivariate distribution. Expressions for the probability density function, for the variances, and for the covariances of the multivariate t-distribution with arbitrary shape parameters for the marginals are given.
Risk-Neutral Pricing of European Call Options: A Specious Concept  [PDF]
Daniel T. Cassidy
Journal of Mathematical Finance (JMF) , 2018, DOI: 10.4236/jmf.2018.82022
Abstract: Risk-neutral pricing of European call options is investigated from a mathematical point-of-view and is found to be a specious concept1. Risk-neutral pricing of European call options is an approximation in which all terms of order \"\"are ignored, where \"\"is the risk premium and σ is the volatility.
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