373 research outputs found

    Oral Communication Apprehension and Its Relationship to Language Achievement and Attitudes Toward the Language Arts

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    This study examined the occurrence of oral communication apprehension (OCA) among 547 sixth grade students in two Maryland schools. The focus was on the relationship between OCA and language achievement, as well as attitudes towards the language arts including sex differences. The Personal Report of Communication Fear Scale (McCroskey, 1977) was administered to categorize the subjects into five OCA levels - Low, Moderately Low, Moderate, Moderately High, and High. The scores gained on the Iowa Test of Basic Skills - Language Subtest were used to assess students' levels of language achievement, and their attitudes toward the language arts were measured by their scores on the Attitudes Toward the Language Arts Scale (Arlin-Hills) Frequencies and percentages were computed for estimating differences in the occurrence of oral communication apprehension among the groups and sexes while Chi-square analysis was used for testing significance of sex differences. Two-way ANOVA and Scheffe test for testing significance of sex differences in language achievement and attitudes to the language arts, as well as one-way ANOVA and intercorrelations of the scores of the PRCF and the two other measures were done to assess relationships between these variables. The following were the findings: 1. The High OCA group consisted of 15 percent of the sample, the Low 16 percent and the three combined Moderate OCA groups 69 percent. 2. Sex differences in the occurrence of OCA at each level were of no statistical significance, but slightly more girls than boys were highly apprehensive about oral communication. 3. The Low and Moderate OCA girls' groups scored significantly higher in language achievement than boys in these groups. 4. Sex differences in attitudes toward the language arts were not significant. 5. There was a relationship between OCA and language achievement indicated by a statistically significant difference among the five group means and the high apprehensives scored below the sample mean, while the low apprehensives scored above. 6. There was no relationship between OCA and attitudes towards the language arts as there was no statistically significant difference among the five OCA group means for the attitude scale

    Chlorpyrifos Affects Phenotypic Outcomes in a Model of Mammalian Neurodevelopment: Critical Stages Targeting Differentiation in PC12 Cells

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    The organophosphate insecticide chlorpyrifos (CPF) adversely affects mammalian brain development through multiple mechanisms. To determine if CPF directly affects neuronal cell replication and phenotypic fate, and to identify the vulnerable stages of differentiation, we exposed PC12 cells, a model for mammalian neurodevelopment, to CPF concentrations spanning the threshold for cholinesterase inhibition (5–50 μM) and conducted evaluations during mitosis and in early and mid-differentiation. In undifferentiated cells, exposure to 5 μM CPF for 1–3 days reduced DNA synthesis significantly without eliciting cytotoxicity. At the same time, CPF increased the expression of tyrosine hydroxylase (TH), the enzymatic marker for the catecholamine phenotype, without affecting choline acetyltransferase (ChAT), the corresponding marker for the cholinergic phenotype. Upon exposure to nerve growth factor (NGF), PC12 cells developed neuritic projections in association with vastly increased TH and ChAT expression accompanying differentiation into the two phenotypes. CPF exposure begun at the start of differentiation significantly reduced ChAT but not TH activity. In contrast, when CPF was added in mid-differentiation (4 days of NGF pretreatment), ChAT was unaffected and TH was increased slightly. Thus, CPF exerts stage-specific effects, reducing DNA synthesis in the undifferentiated state, impairing development of the cholinergic phenotype at the start of differentiation, and promoting expression of the catecholaminergic phenotype both in undifferentiated and differentiated cells. CPF administration in vivo produces deficits in the number of neurons and cholinergic function, and because we were able to reproduce these effects in vitro, our results suggest that CPF directly influences the phenotypic fate of neuronal precursors

    Modeling Women's Elective Choices in Computing

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    Evidence-based strategies suggest ways to reduce the gender gap in computing. For example, elective classes are valuable in enabling students to choose in which directions to expand their computing knowledge in areas aligned with their interests. The availability of electives of interest may also make computing programs of study more meaningful to women. However, research on which elective computing topics are more appealing to women is often class or institution specific. In this study, we investigate differences in enrollment within undergraduate-level elective classes in computing to study differences between women and men. The study combined data from nine institutions from both Western Europe and North America and included 272 different classes with 49,710 student enrollments. These classes were encoded using ACM curriculum guidelines and combined with the enrollment data to build a hierarchical statistical model of factors affecting student choice. Our model shows which elective topics are less popular with all students (including fundamentals of programming languages and parallel and distributed computing), and which elective topics are more popular with women students (including mathematical and statistical foundations, human computer interaction and society, ethics, and professionalism). Understanding which classes appeal to different students can help departments gain insight of student choices and develop programs accordingly. Additionally, these choices can also help departments explore whether some students are less likely to choose certain classes than others, indicating potential barriers to participation in computing

    Large Scale Parallelization in Stochastic Coupled Cluster

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    Coupled cluster theory is a vital cornerstone of electronic structure theory and is being applied to ever-larger systems. Stochastic approaches to quantum chemistry have grown in importance and offer compelling advantages over traditional deterministic algorithms in terms of computational demands, theoretical flexibility or lower scaling with system size. We present a highly parallelizable algorithm of the coupled cluster Monte Carlo method involving sampling of clusters of excitors over multiple time steps. The behaviour of the algorithm is investigated on the uniform electron gas and the water dimer at CCSD, CCSDT and CCSDTQ levels. We also describe two improvements to the original sampling algorithm, full non-composite and multi-spawn sampling. A stochastic approach to coupled cluster results in an efficient and scalable implementation at arbitrary truncation levels in the coupled cluster expansion.Thomas Young Centre TYC-101, EPSRC Centre for Doctoral Training in Computational Methods for Materials Science EP/L015552/1, Cambridge Philosophical Society, EPSRC, CHESS, Royal Society University Research Fellowship UF110161 and UF160398, ARCHER UK National Supercomputing Service (http://www.archer.ac.uk) grant e507, UK Research Data Facility (http://www.archer.ac.uk/documentation/rdf-guide) grant e507, resources provided by the Cambridge Service for Data Driven Discovery (CSD3) operated by the University of Cambridge Research Computing Service (http://www.csd3.cam.ac.uk/), provided by Dell EMC and Intel using Tier-2 funding from the Engineering and Physical Sci- ences Research Council (capital grant EP/P020259/1), and DiRAC funding from the Science and Technology Facilities Council (www.dirac.ac.uk

    Fixed-combination, low-dose, triple-pill antihypertensive medication versus usual care in patients with mild-to-moderate hypertension in Sri Lanka: a within-trial and modelled economic evaluation of the TRIUMPH trial.

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    BACKGROUND: Elevated blood pressure incurs a major health and economic burden, particularly in low-income and middle-income countries. The Triple Pill versus Usual Care Management for Patients with Mild-to-Moderate Hypertension (TRIUMPH) trial showed a greater reduction in blood pressure in patients using fixed-combination, low-dose, triple-pill antihypertensive therapy (consisting of amlodipine, telmisartan, and chlorthalidone) than in those receiving usual care in Sri Lanka. We aimed to assess the cost-effectiveness of the triple-pill strategy. METHODS: We did a within-trial (6-month) and modelled (10-year) economic evaluation of the TRIUMPH trial, using the health system perspective. Health-care costs, reported in 2017 US dollars, were determined from trial records and published literature. A discrete-time simulation model was developed, extrapolating trial findings of reduced systolic blood pressure to 10-year health-care costs, cardiovascular disease events, and mortality. The primary outcomes were the proportion of people reaching blood pressure targets (at 6 months from baseline) and disability-adjusted life-years (DALYs) averted (at 10 years from baseline). Incremental cost-effectiveness ratios were calculated to estimate the cost per additional participant achieving target blood pressure at 6 months and cost per DALY averted over 10 years. FINDINGS: The triple-pill strategy, compared with usual care, cost an additional US963(959·63 (95% CI 5·29 to 13·97) per person in the within-trial analysis and 347·75 (285·55 to 412·54) per person in the modelled analysis. Incremental cost-effectiveness ratios were estimated at 793(957·93 (95% CI 6·59 to 11·84) per participant reaching blood pressure targets at 6 months and 2842·79 (-28·67 to 5714·24) per DALY averted over a 10-year period. INTERPRETATION: Compared with usual care, the triple-pill strategy is cost-effective for patients with mild-to-moderate hypertension. Scaled up investment in the triple pill for hypertension management in Sri Lanka should be supported to address the high population burden of cardiovascular disease. FUNDING: Australian National Health and Medical Research Council

    The HANDE-QMC Project: Open-Source Stochastic Quantum Chemistry from the Ground State Up.

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    Building on the success of Quantum Monte Carlo techniques such as diffusion Monte Carlo, alternative stochastic approaches to solve electronic structure problems have emerged over the past decade. The full configuration interaction quantum Monte Carlo (FCIQMC) method allows one to systematically approach the exact solution of such problems, for cases where very high accuracy is desired. The introduction of FCIQMC has subsequently led to the development of coupled cluster Monte Carlo (CCMC) and density matrix quantum Monte Carlo (DMQMC), allowing stochastic sampling of the coupled cluster wave function and the exact thermal density matrix, respectively. In this Article, we describe the HANDE-QMC code, an open-source implementation of FCIQMC, CCMC and DMQMC, including initiator and semistochastic adaptations. We describe our code and demonstrate its use on three example systems; a molecule (nitric oxide), a model solid (the uniform electron gas), and a real solid (diamond). An illustrative tutorial is also included

    A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

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    Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia

    A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

    Get PDF
    Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia
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