Centralizers of normal subgroups and the Z*-theorem

Peer reviewed

Centralizers of normal subgroups and the Z*-theorem

Peer reviewed

Centralizers of normal subgroups and the Z*-theorem

Peer reviewed

Searching for Predictive Subgroups

Thesis (Ph.D.)--University of Washington, 2016-08

Social engagement and adaptive functioning during early childhood: Identifying and distinguishing among subgroups differing with regard to social engagement

This study tested the hypothesis that social engagement (SE) with peers is a fundamental aspect of social competence during early childhood. Relations between SE and a set of previously validated social competence indicators, as well as additional variables derived from observation and sociometric interviews were assessed using both variable-centered and person-centered approaches (N = 1453, 696 girls) in 4 samples (3 U.S.A., 1 Portuguese). Directly observed SE was positively associated with broad-band measures of socially competent behavior, peer acceptance, being a target of peers' attention, and also with broad-band personality dimensions. Using individual Q-items significantly associated with SE in 3 of our 4 samples, a hierarchical cluster analysis yielded a 5-cluster solution that grouped cases efficiently. Tests on relations between cluster membership and the set of social competence and other variables revealed significant main effects of cluster membership in the full sample and within each individual sample, separately. With the exception of tests for peer negative preference, children in the lowest SE cluster also had significantly lower overall social competence, personality functioning scores than did children in higher SE clusters.

Social engagement and adaptive functioning during early childhood: Identifying and distinguishing among subgroups differing with regard to social engagement

Materia Suplementar disponível em: http://dx.doi.org/10.1037/dev0000142.supp

The relationship between deformity correction and clinical outcomes after thoracoscopic scoliosis surgery

Surgical treatment of scoliosis is quantitatively assessed in the clinic using radiographic measures of deformity correction, as well as the rib hump, but it is important to understand the extent to which these quantitative measures correlate with self-reported improvements in patients’ quality of life following surgery. The purpose of this prospective study was to evaluate the relationship between clinical outcomes of thoracoscopic anterior scoliosis surgery and deformity correction using the Scoliosis Research Society questionnaire (SRS-24). Patients undergoing thoracoscopic anterior scoliosis correction report good SRS scores which are comparable to those reported in previous studies for both open and thoracoscopic scoliosis correction procedures. Major Cobb correction is a significant predictor of patient satisfaction when comparing subgroups of patients with the highest and lowest major curve corrections.

Defining friendworks : communication perspective on social networks types

This paper introduces friendwork as a new term in social networks studies. A friendwork is a network of friends. It is a specific case of an interpersonal social network. Naming this seemingly well known and familiar group of people as a friendwork facilitates its differentiation from the overall social network, while highlighting this subgroup's specific attributes and dynamics. The focus on one segment within social networks stimulates a wider discussion regarding the different subgroups within social networks. Other subgroups also discussed in this paper are: family dependent, work related, location based and virtual acquaintances networks. This discussion informs a larger study of social media, specifically addressing interactive communication modes that are in use within friendworks: direct (face-to-face) and mediated (mainly fixed telephone, internet and mobile phone). It explores the role of social media within friendworks while providing a communication perspective on social networks.

Longitudinal patterns of weight in women diagnosed with breast cancer [Conference Abstract]

Introduction: Weight gain is a common concern following breast cancer and has been associated with negative health outcomes. As such, prevention of weight gain is of clinical interest. This work describes weight change between 6- and 18-months following a breast cancer diagnosis and explores the personal, treatment and behavioural characteristics associated with gains in weight. Methods: Body mass index was objectively assessed, at three-monthly intervals, on a population-based sample of women newly diagnosed with unilateral breast cancer (n=185). Changes in BMI between 6- and 18-months post-diagnosis were calculated, with gains of one or more being considered clinically detrimental to future health. Results: Approximately 60% of participants were overweight or obese at 6-months post-diagnosis. While BMI remained relatively stable across the testing period (range=27.3-27.8), 24% of participants experienced clinically relevant gains in BMI (median gains=1.9). Following adjustment for potential confounders, younger age (<45 years; Odds ratio, OR=9.8), being morbidly obese at baseline (OR=4.6) and receiving hormone therapy (OR=4.8) were characteristics associated with an increased odds (p<0.05) of gaining BMI. Other characteristics associated with gains in BMI were more extensive surgery and having a history of smoking, although these relationships were not supported statistically. In contrast, caring for younger children was associated with reduced risk of gaining BMI (OR=0.3, p=0.20). Conclusions: Clinically relevant weight gain between 6- and 18-months post-breast cancer diagnosis is an issue for one in four women, with certain subgroups being particularly susceptible. However, the majority of women diagnosed with breast cancer are overweight or obese and gains in body weight are common. Thus, interventions that address the importance of achieving and sustaining a healthy body weight, delivered to all women with breast cancer, may have greater public health impact than interventions targeting any specific breast cancer subgroup.

Management of comorbidity

Comorbidity of substance use disorders and mental disorders is very common, and there is substantial heterogeneity within subgroups in terms of both their characteristics and the nature of causal relationships between the disorders. Assessment and management strategies need to deal with both the size of the problem across the community and its severe impact in some subgroups, including those with psychosis. At this stage, the research base from which we can derive recommendations is very narrow, but it does offer a foundation for preliminary conclusions. This chapter reviews the current evidence and makes some suggestions for assessment and for both psychological and pharmacological management.

Confidence to cook vegetables and the buying habits of Australian households

Cooking skills are emphasized in nutrition promotion but their distribution among population subgroups and relationship to dietary behavior is researched by few population-based studies. This study examined the relationships between confidence to cook, sociodemographic characteristics, and household vegetable purchasing. This cross-sectional study of 426 randomly selected households in Brisbane, Australia, used a validated questionnaire to assess household vegetable purchasing habits and the confidence to cook of the person who most often prepares food for these households. The mutually adjusted odds ratios (ORs) of lacking confidence to cook were assessed across a range of demographic subgroups using multiple logistic regression models. Similarly, mutually adjusted mean vegetable purchasing scores were calculated using multiple linear regression for different population groups and for respondents with varying confidence levels. Lacking confidence to cook using a variety of techniques was more common among respondents with less education (OR 3.30; 95% confidence interval [CI] 1.01 to 10.75) and was less common among respondents who lived with minors (OR 0.22; 95% CI 0.09 to 0.53) and other adults (OR 0.43; 95% CI 0.24 to 0.78). Lack of confidence to prepare vegetables was associated with being male (OR 2.25; 95% CI 1.24 to 4.08), low education (OR 6.60; 95% CI 2.08 to 20.91), lower household income (OR 2.98; 95% CI 1.02 to 8.72) and living with other adults (OR 0.53; 95% CI 0.29 to 0.98). Households bought a greater variety of vegetables on a regular basis when the main chef was confident to prepare them (difference: 18.60; 95% CI 14.66 to 22.54), older (difference: 8.69; 95% CI 4.92 to 12.47), lived with at least one other adult (difference: 5.47; 95% CI 2.82 to 8.12) or at least one minor (difference: 2.86; 95% CI 0.17 to 5.55). Cooking skills may contribute to socioeconomic dietary differences, and may be a useful strategy for promoting fruit and vegetable consumption, particularly among socioeconomically disadvantaged groups.

Does quality of life among breast cancer survivors one year after diagnosis differ depending on urban and non-urban residence? A comparative study

Background: This study examined the quality of life (QOL), measured by the Functional Assessment of Cancer Therapy (FACT) questionnaire, among urban (n=277) and non-urban (n=323) breast cancer survivors and women from the general population (n=1140) in Queensland, Australia. ---------- Methods: Population-based samples of breast cancer survivors aged <75 years who were 12 months post-diagnosis and similarly-aged women from the general population were recruited between 2002 and 2007. ---------- Results: Age-adjusted QOL among urban and non-urban breast cancer survivors was similar, although QOL related to breast cancer concerns was the weakest domain and was lower among non-urban survivors than their urban counterparts (36.8 versus 40.4, P<0.01). Irrespective of residence, breast cancer survivors, on average, reported comparable scores on most QOL scales as their general population peers, although physical well-being was significantly lower among non-urban survivors (versus the general population, P<0.01). Overall, around 20%-33% of survivors experienced lower QOL than peers without the disease. The odds of reporting QOL below normative levels were increased more than two-fold for those who experienced complications following surgery, reported upper-body problems, had higher perceived stress levels and/or a poor perception of handling stress (P<0.01 for all). ---------- Conclusions: Results can be used to identify subgroups of women at risk of low QOL and to inform components of tailored recovery interventions to optimize QOL for these women following cancer treatment.

Bayesian models for longitudinal data

Longitudinal data, where data are repeatedly observed or measured on a temporal basis of time or age provides the foundation of the analysis of processes which evolve over time, and these can be referred to as growth or trajectory models. One of the traditional ways of looking at growth models is to employ either linear or polynomial functional forms to model trajectory shape, and account for variation around an overall mean trend with the inclusion of random eects or individual variation on the functional shape parameters. The identification of distinct subgroups or sub-classes (latent classes) within these trajectory models which are not based on some pre-existing individual classification provides an important methodology with substantive implications. The identification of subgroups or classes has a wide application in the medical arena where responder/non-responder identification based on distinctly diering trajectories delivers further information for clinical processes. This thesis develops Bayesian statistical models and techniques for the identification of subgroups in the analysis of longitudinal data where the number of time intervals is limited. These models are then applied to a single case study which investigates the neuropsychological cognition for early stage breast cancer patients undergoing adjuvant chemotherapy treatment from the Cognition in Breast Cancer Study undertaken by the Wesley Research Institute of Brisbane, Queensland. Alternative formulations to the linear or polynomial approach are taken which use piecewise linear models with a single turning point, change-point or knot at a known time point and latent basis models for the non-linear trajectories found for the verbal memory domain of cognitive function before and after chemotherapy treatment. Hierarchical Bayesian random eects models are used as a starting point for the latent class modelling process and are extended with the incorporation of covariates in the trajectory profiles and as predictors of class membership. The Bayesian latent basis models enable the degree of recovery post-chemotherapy to be estimated for short and long-term followup occasions, and the distinct class trajectories assist in the identification of breast cancer patients who maybe at risk of long-term verbal memory impairment.