520 research outputs found

    PATHWAYS TO EARLY PREGNANCY BY RACE/ETHNIC AND CLASS LOCATIONS: ADOLESCENT GIRLS' SELF-CONCEPTS AND AMBIVALENCE TOWARDS PREGNANCY

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    An important paradox in adolescent pregnancy is that adolescent girls' stronger self-concepts (e.g., higher efficacy and self-esteem) are thought to reduce the likelihood of becoming pregnant: However, minority adolescents, particularly Black girls, have equal or stronger self-concepts than White girls, yet have higher pregnancy and birth rates in adolescence. Thus, the self-concept (or different components of the self) may operate differently for Black and Hispanic girls than White girls, either being positively related or unrelated to pregnancy. One way to disentangle the paradox is to focus on girls' feelings about becoming pregnant and their initial sexual decisions, which serve as more proximate determinants and occur prior to contraceptive behaviors and the occurrence of pregnancy. Based on a theoretical framework grounded in intersectionality and symbolic interactionism and utilizing the National Longitudinal Study of Adolescent Health (Add Health, N = 5,735), this dissertation examines the influence of adolescent girls' self-concepts, including self-efficacy, perceived mattering, self-esteem and possible selves, on two primary outcomes--feelings of ambivalence towards pregnancy and the transition to first sexual intercourse--and how these relationships vary by race/ethnicity and social class. Statistical methods include discrete-time event history analysis and OLS and logistic regression. Results generally indicate that stronger self-concepts, in particular self-efficacy, mattering, and educational possible selves, are protective against girls' feelings of ambivalence towards pregnancy one year later. Two- and three-way interactions reveal that the relationship between educational expectations and aspirations and ambivalence varies by girls' race and class locations. Educational aspirations are protective for high-SES White girls and low-SES Black girls whereas educational expectations are protective for low-SES White and high-SES Black girls. Girls' perceived mattering is protective against an early transition to first sexual intercourse, particularly for low-SES girls. Ambivalence towards pregnancy is positively related to an early transition to first sexual intercourse and this relationship varies by race/ethnicity and class. This dissertation highlights contingencies by race/ethnic and social class locations and the complexity of the influence of girls' self-concepts in understanding the pathways leading to adolescent fertility

    Study program for encapsulation materials interface for low-cost solar array

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    The service integrity of the bonded interface in solar cell modules used in solar arrays is addressed. The development of AC impedance as a nondestructive evaluation (NDE) methodology for solar arrays is reported along with development of corrosion models and materials selection criteria for corrosion resistant interfaces

    The role of serotonin 1B in the representation of outcomes.

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    Disrupted serotonin neurotransmission has been implicated in the etiology of psychopathic traits. Empirical research has found that people with high levels of psychopathic traits have a deficit in reinforcement learning that is thought to be linked with amygdala dysfunction. Altered serotonin neurotransmission provides a plausible explanation for amygdala dysfunction in psychopathic traits and recent research suggests that this may be associated with serotonin 1B (5-HT1B) receptor function. This research used an animal model to test the hypothesis that 5-HT1B receptors are involved in the encoding of the specific features of reinforcing outcomes. An outcome devaluation task was used to test the effect of the systemic administration of a selective 5-HT1B receptor agonist administered before encoding of "action-outcome" associations. Results showed that while administration of a 5-HT1B receptor agonist allowed rats to acquire instrumental responding for food, when the content of that learning was further probed using an outcome devaluation task, performance differed from controls. 5-HT1B agonism impaired learning about the specific sensory qualities of food rewards associated with distinct instrumental responses, required to direct choice performance when the value of one outcome changed. These findings suggest a role for 5-HT1B receptor function in the encoding of the specific features of reinforcing outcomes

    Family Structure Differences In Maternal Time With Children: Disparate Social Structural Locations Or Different Propensities Towards Mothering?

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    Utilizing the 2003 and 2004 American Time Use Survey (ATUS), this thesis examines the relationship between family structure and maternal time with children. The large sample, composed of 4,309 married mothers and 1,821 single mothers with children less than 13 years of age, allows for a detail-rich description of single mothers' time with their children that has not been possible before the ATUS. This thesis analyzes differences in maternal time with children by marital status, living arrangements, and other characteristics within the single mother population and in comparison to married mothers. Findings indicate that differences in maternal time with children largely disappear or that single mothers engage in more child care than married mothers after controls are introduced. Thus, differences in maternal time with children appear to be mainly attributable to the disadvantaged social structural location of single mothers rather than different proclivities towards mothering between married and single mothers

    Grounding knowledge and normative valuation in agent-based action and scientific commitment

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    Philosophical investigation in synthetic biology has focused on the knowledge-seeking questions pursued, the kind of engineering techniques used, and on the ethical impact of the products produced. However, little work has been done to investigate the processes by which these epistemological, metaphysical, and ethical forms of inquiry arise in the course of synthetic biology research. An attempt at this work relying on a particular area of synthetic biology will be the aim of this chapter. I focus on the reengineering of metabolic pathways through the manipulation and construction of small DNA-based devices and systems synthetic biology. Rather than focusing on the engineered products or ethical principles that result, I will investigate the processes by which these arise. As such, the attention will be directed to the activities of practitioners, their manipulation of tools, and the use they make of techniques to construct new metabolic devices. Using a science-in-practice approach, I investigate problems at the intersection of science, philosophy of science, and sociology of science. I consider how practitioners within this area of synthetic biology reconfigure biological understanding and ethical categories through active modelling and manipulation of known functional parts, biological pathways for use in the design of microbial machines to solve problems in medicine, technology, and the environment. We might describe this kind of problem-solving as relying on what Helen Longino referred to as “social cognition” or the type of scientific work done within what Hasok Chang calls “systems of practice”. My aim in this chapter will be to investigate the relationship that holds between systems of practice within metabolic engineering research and social cognition. I will attempt to show how knowledge and normative valuation are generated from this particular network of practitioners. In doing so, I suggest that the social nature of scientific inquiry is ineliminable to both knowledge acquisition and ethical evaluations

    The effectiveness of an aged care specific leadership and management program on workforce, work environment, and care quality outcomes: design of a cluster randomised controlled trial

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    BACKGROUND: A plethora of observational evidence exists concerning the impact of management and leadership on workforce, work environment, and care quality. Yet, no randomised controlled trial has been conducted to test the effectiveness of leadership and management interventions in aged care. An innovative aged care clinical leadership program (Clinical Leadership in Aged Care − CLiAC) was developed to improve managers’ leadership capacities to support the delivery of quality care in Australia. This paper describes the study design of the cluster randomised controlled trial testing the effectiveness of the program. METHODS: Twenty-four residential and community aged care sites were recruited as managers at each site agreed in writing to participate in the study and ensure that leaders allocated to the control arm would not be offered the intervention program. Sites undergoing major managerial or structural changes were excluded. The 24 sites were randomly allocated to receive the CLiAC program (intervention) or usual care (control), stratified by type (residential vs. community, six each for each arm). Treatment allocation was masked to assessors and staff of all participating sites. The objective is to establish the effectiveness of the CLiAC program in improving work environment, workforce retention, as well as care safety and quality, when compared to usual care. The primary outcomes are measures of work environment, care quality and safety, and staff turnover rates. Secondary outcomes include manager leadership capacity, staff absenteeism, intention to leave, stress levels, and job satisfaction. Differences between intervention and control groups will be analysed by researchers blinded to treatment allocation using linear regression of individual results adjusted for stratification and clustering by site (primary analysis), and additionally for baseline values and potential confounders (secondary analysis). Outcomes measured at the site level will be compared by cluster-level analysis. The overall costs and benefits of the program will also be assessed. DISCUSSION: The outcomes of the trial have the potential to inform actions to enhance leadership and management capabilities of the aged care workforce, address pressing issues about workforce shortages, and increase the quality of aged care services

    Integrability and level crossing manifolds in a quantum Hamiltonian system

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    We consider a two-spin model, represented classically by a nonlinear autonomous Hamiltonian system with two degrees of freedom and a nontrivial integrability condition, and quantum mechanically by a real symmetric Hamiltonian matrix with blocks of dimensionalities K=l(l+1)/2, l=1,2,... In the six-dimensional (6D) parameter space of this model, classical integrability is satisfied on a 5D hypersurface, and level crossings occur on 4D manifolds that are completely embedded in the integrability hypersurface except for some lower-D sub-manifolds. Under mild assumptions, the classical integrability condition can be reconstructed from a purely quantum mechanical study of level degeneracies in finite-dimensional invariant blocks of the Hamiltonian matrix. Our conclusions are based on rigorous results for K=3 and on numerical results for K=6,10.Comment: 8 pages, 3 figure

    Phorbol 12,13-Dibutyrate-Induced, Protein Kinase C-Mediated Contraction of Rabbit Bladder Smooth Muscle

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    Contraction of bladder smooth muscle is predominantly initiated by M3 muscarinic receptor-mediated activation of the Gq/11-phospholipase C β-protein kinase C (PKC) and the G12/13-RhoGEF-Rho kinase (ROCK) pathways. However, these pathways and their downstream effectors are not well understood in bladder smooth muscle. We used phorbol 12,13-dibutyrate (PDBu), and 1,2-dioctanoyl-sn-glycerol (DOG), activators of PKC, in this investigation. We were interested in dissecting the role(s) of PKC and to clarify the signaling pathways in bladder smooth muscle contraction, especially the potential cross-talk with ROCK and their downstream effectors in regulating myosin light chain phosphatase activity and force. To achieve this goal, the study was performed in the presence or absence of the PKC inhibitor bisindolylmaleimide-1 (Bis) or the ROCK inhibitor H-1152. Phosphorylation levels of Thr38-CPI-17 and Thr696/Thr850 myosin phosphatase target subunit (MYPT1) were measured during PDBu or DOG stimulation using site specific antibodies. PDBu-induced contraction in bladder smooth muscle involved both activation of PKC and PKC-dependent activation of ROCK. CPI-17 as a major downstream effector, is phosphorylated by PKC and ROCK during PDBu and DOG stimulation. Our results suggest that Thr696 and Thr850-MYPT1 phosphorylation are not involved in the regulation of a PDBu-induced contraction. The results also demonstrate that bladder smooth muscle contains a constitutively active isoform of ROCK that may play an important role in the regulation of bladder smooth muscle basal tone. Together with the results from our previous study, we developed a working model to describe the complex signaling pathways that regulate contraction of bladder smooth muscle

    The effectiveness of an aged care specific leadership and management program on workforce, work environment, and care quality outcomes: Design of a cluster randomised controlled trial

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    Background: A plethora of observational evidence exists concerning the impact of management and leadership on workforce, work environment, and care quality. Yet, no randomised controlled trial has been conducted to test the effectiveness of leadership and management interventions in aged care. An innovative aged care clinical leadership program (Clinical Leadership in Aged Care - CLiAC) was developed to improve managers' leadership capacities to support the delivery of quality care in Australia. This paper describes the study design of the cluster randomised controlled trial testing the effectiveness of the program.Methods: Twenty-four residential and community aged care sites were recruited as managers at each site agreed in writing to participate in the study and ensure that leaders allocated to the control arm would not be offered the intervention program. Sites undergoing major managerial or structural changes were excluded. The 24 sites were randomly allocated to receive the CLiAC program (intervention) or usual care (control), stratified by type (residential vs. community, six each for each arm). Treatment allocation was masked to assessors and staff of all participating sites. The objective is to establish the effectiveness of the CLiAC program in improving work environment, workforce retention, as well as care safety and quality, when compared to usual care. The primary outcomes are measures of work environment, care quality and safety, and staff turnover rates. Secondary outcomes include manager leadership capacity, staff absenteeism, intention to leave, stress levels, and job satisfaction. Differences between intervention and control groups will be analysed by researchers blinded to treatment allocation using linear regression of individual results adjusted for stratification and clustering by site (primary analysis), and additionally for baseline values and potential confounders (secondary analysis). Outcomes measured at the site level will be compared by cluster-level analysis. The overall costs and benefits of the program will also be assessed.Discussion: The outcomes of the trial have the potential to inform actions to enhance leadership and management capabilities of the aged care workforce, address pressing issues about workforce shortages, and increase the quality of aged care services. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12611001070921). © 2013 Jeon et al.; licensee BioMed Central Ltd

    Cluster randomized controlled trial of an aged care specific leadership and management program to improve work environment, staff turnover, and care quality

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    OBJECTIVE To evaluate the effectiveness of a leadership and management program in aged care. DESIGN Double-blind cluster randomized controlled trial. SETTING Twelve residential and community-aged care sites in Australia. PARTICIPANTS All care staff employed for 6 months or longer at the aged care sites were invited to participate in the surveys at 3 time points: baseline (time 1), 9 months from baseline (time 2), and 9 months after completion of time 2 (time 3) from 2011 to 2013. At each time point, at least 500 care staff completed a survey. At baseline (N = 503) the largest age group was 45 to 54 years (37%), and the majority of care staff were born in Australia (70%), spoke English (94%), and had at least completed secondary education (57%). INTERVENTION A 12-month Clinical Leadership in Aged Care (CLiAC) program for middle managers, which aimed to further develop their leadership and management skills in creating positive workplace relationships and in enabling person-centered, evidence-based care. MAIN OUTCOME MEASURES The primary outcomes were care staff ratings of the work environment, care quality and safety, and staff turnover rates. Secondary outcomes were care staff's intention to leave their employer and profession, workplace stress, job satisfaction, and cost-effectiveness of implementing the program. Absenteeism was excluded due to difficulty in obtaining reliable data. Managers' self-rated knowledge and skills in leadership and management are not included in this article, which focuses on care staff perceptions only. RESULTS At 6 months after its completion, the CLiAC program was effective in improving care staff's perception of management support [mean difference 0.61, 95% confidence interval (CI) 0.04-1.18; P = .04]. Compared with the control sites, care staff at the intervention sites perceived their managers' leadership styles as more transformational (mean difference 0.30, 95% CI 0.09-0.51; P = .005), transactional (mean difference 0.22, 95% CI 0.05-0.39; P = .01), and less passive avoidant (mean difference 0.30, 95% CI 0.07-0.52; P = .01); and were rated higher on the overall leadership outcomes (mean difference 0.35, 95% CI 0.13-0.56; P = .001) as well as individual manager outcomes: extra effort (P = .004), effectiveness (P = .001), and satisfaction (P = .01). There was no evidence that CLiAC was effective in reducing staff turnover, or improving patient care quality and safety. CONCLUSIONS While the CLiAC leadership program had direct impact on the primary process outcomes (management support, leadership actions, behaviors, and effects), this was insufficient to change the systems required to support care service quality and client safety. Nevertheless, the findings send a strong message that leadership and management skills in aged care managers can be nurtured and used to change leadership behaviors at a reasonable cost
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