1,181 research outputs found

    Resonances from meson-meson scattering in U(3) CHPT

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    In this work, the complete one loop calculation of meson-meson scattering amplitudes within U(3)\otimes U(3) chiral perturbation theory with explicit resonance states is carried out for the first time. Partial waves are unitarized from the perturbative calculation employing a non-perturbative approach based on the N/D method. Once experimental data are reproduced in a satisfactory way we then study the resonance properties, such as the pole positions, corresponding residues and their N_C behaviors. The resulting N_C dependence is the first one in the literature that takes into account the fact that the \eta_1 becomes the ninth Goldstone boson in the chiral limit for large N_C. Within this scheme the vector resonances studied, \rho(770), K^*(892) and \phi(1020), follow an N_C trajectory in agreement with their standard \bar{q}q interpretation. The scalars f_0(1370), a_0(1450) and K^*(1430) also have for large N_C a \bar{q}q pole position trajectory and all of them tend to a bare octet of scalar resonances around 1.4 GeV. The f_0(980) tends asymptotically to the bare pole position of a singlet scalar resonance around 1 GeV. The \sigma, \kappa and a_0(980) scalar resonances have a very different N_C behavior. The case of the \sigma resonance is analyzed with special detail.Comment: 50 pages, 15 figures, 1 table. Enlarged version with more detail comparisons with previous results in the literature. To match with accepted version for publicatio

    Pion Interactions in Chiral Field Theories

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    We study in various chiral models the pion charge radius, πe3\pi_{e3} form factor ratio, πγγ\pi^\circ \to \gamma \gamma amplitude, charge pion polarizabilities, γγππ\gamma\gamma \to \pi^\circ \pi^\circ amplitude at low energies and the ππ\pi\pi s-wave I = 0 scattering length. We find that a quark-level linear sigma-model approach (also being consistent with tree-level vector meson dominance) is quite compatible with all of the above data.Comment: 12 pages, 9 eps figure

    Advancing the argument for validity of the Alberta Context Tool with healthcare aides in residential long-term care

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    <p>Abstract</p> <p>Background</p> <p>Organizational context has the potential to influence the use of new knowledge. However, despite advances in understanding the theoretical base of organizational context, its measurement has not been adequately addressed, limiting our ability to quantify and assess context in healthcare settings and thus, advance development of contextual interventions to improve patient care. We developed the Alberta Context Tool (the ACT) to address this concern. It consists of 58 items representing 10 modifiable contextual concepts. We reported the initial validation of the ACT in 2009. This paper presents the second stage of the psychometric validation of the ACT.</p> <p>Methods</p> <p>We used the <it>Standards for Educational and Psychological Testing </it>to frame our validity assessment. Data from 645 English speaking healthcare aides from 25 urban residential long-term care facilities (nursing homes) in the three Canadian Prairie Provinces were used for this stage of validation. In this stage we focused on: (1) advanced aspects of internal structure (e.g., confirmatory factor analysis) and (2) relations with other variables validity evidence. To assess reliability and validity of scores obtained using the ACT we conducted: Cronbach's alpha, confirmatory factor analysis, analysis of variance, and tests of association. We also assessed the performance of the ACT when individual responses were aggregated to the care unit level, because the instrument was developed to obtain unit-level scores of context.</p> <p>Results</p> <p>Item-total correlations exceeded acceptable standards (> 0.3) for the majority of items (51 of 58). We ran three confirmatory factor models. Model 1 (all ACT items) displayed unacceptable fit overall and for five specific items (1 item on <it>adequate space for resident care </it>in the Organizational Slack-Space ACT concept and 4 items on use of electronic resources in the Structural and Electronic Resources ACT concept). This prompted specification of two additional models. Model 2 used the 7 scaled ACT concepts while Model 3 used the 3 count-based ACT concepts. Both models displayed substantially improved fit in comparison to Model 1. Cronbach's alpha for the 10 ACT concepts ranged from 0.37 to 0.92 with 2 concepts performing below the commonly accepted standard of 0.70. Bivariate associations between the ACT concepts and instrumental research utilization levels (which the ACT should predict) were statistically significant at the 5% level for 8 of the 10 ACT concepts. The majority (8/10) of the ACT concepts also showed a statistically significant trend of increasing mean scores when arrayed across the lowest to the highest levels of instrumental research use.</p> <p>Conclusions</p> <p>The validation process in this study demonstrated additional empirical support for construct validity of the ACT, when completed by healthcare aides in nursing homes. The overall pattern of the data was consistent with the structure hypothesized in the development of the ACT and supports the ACT as an appropriate measure for assessing organizational context in nursing homes. Caution should be applied in using the one space and four electronic resource items that displayed misfit in this study with healthcare aides until further assessments are made.</p

    Development and assessment of the Alberta Context Tool

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    <p>Abstract</p> <p>Background</p> <p>The context of healthcare organizations such as hospitals is increasingly accepted as having the potential to influence the use of new knowledge. However, the mechanisms by which the organizational context influences evidence-based practices are not well understood. Current measures of organizational context lack a theory-informed approach, lack construct clarity and generally have modest psychometric properties. This paper presents the development and initial psychometric validation of the Alberta Context Tool (ACT), an eight dimension measure of organizational context for healthcare settings.</p> <p>Methods</p> <p>Three principles guided the development of the ACT: substantive theory, brevity, and modifiability. The Promoting Action on Research Implementation in Health Services (PARiHS) framework and related literature were used to guide selection of items in the ACT. The ACT was required to be brief enough to be tolerated in busy and resource stretched work settings and to assess concepts of organizational context that were potentially <it>modifiable</it>. The English version of the ACT was completed by 764 nurses (752 valid responses) working in seven Canadian pediatric care hospitals as part of its initial validation. Cronbach's alpha, exploratory factor analysis, analysis of variance, and tests of association were used to assess instrument reliability and validity.</p> <p>Results</p> <p>Factor analysis indicated a 13-factor solution (accounting for 59.26% of the variance in 'organizational context'). The composition of the factors was similar to those originally conceptualized. Cronbach's alpha for the 13 factors ranged from .54 to .91 with 4 factors performing below the commonly accepted alpha cut off of .70. Bivariate associations between instrumental research utilization levels (which the ACT was developed to predict) and the ACT's 13 factors were statistically significant at the 5% level for 12 of the 13 factors. Each factor also showed a trend of increasing mean score ranging from the lowest level to the highest level of instrumental research use, indicating construct validity.</p> <p>Conclusions</p> <p>To date, no completely satisfactory measures of organizational context are available for use in healthcare. The ACT assesses several core domains to provide a comprehensive account of organizational context in healthcare settings. The tool's strengths are its brevity (allowing it to be completed in busy healthcare settings) and its focus on dimensions of organizational context that are modifiable. Refinements of the instrument for acute, long term care, and home care settings are ongoing.</p

    Nursing home administrators’ perspectives on a study feedback report : a cross sectional survey

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    BackgroundThis project is part of the Translating Research in Elder Care (TREC) program of research, a multi-level and longitudinal research program being conducted in 36 nursing homes in three Canadian Prairie Provinces. The overall goal of TREC is to improve the quality of care for older persons living in nursing homes and the quality of work life for care providers. The purpose of this paper is to report on development and evaluation of facility annual reports (FARs) from facility administrators&rsquo; perspectives on the usefulness, meaningfulness, and understandability of selected data from the TREC survey. MethodsA cross sectional survey design was used in this study. The feedback reports were developed in collaboration with participating facility administrators. FARs presented results in four contextual areas: workplace culture, feedback processes, job satisfaction, and staff burnout. Six weeks after FARs were mailed to each administrator, we conducted structured telephone interviews with administrators to elicit their evaluation of the FARs. Administrators were also asked if they had taken any actions as a result of the FAR. Descriptive and inferential statistics, as well as content analysis for open-ended questions, were used to summarize findings. ResultsThirty-one facility administrators (representing thirty-two facilities) participated in the interviews. Six administrators had taken action and 18 were planning on taking action as a result of FARs. The majority found the four contextual areas addressed in FAR to be useful, meaningful, and understandable. They liked the comparisons made between data from years one and two and between their facility and other TREC study sites in their province. Twenty-two indicated that they would like to receive information on additional areas such as aggressive behaviours of residents and information sharing. Twenty-four administrators indicated that FARs contained enough information, while eight found FARs &lsquo;too short&rsquo;. Administrators who reported that the FAR contained enough information were more likely to take action within their facilities than administrators who reported that they needed more information. ConclusionsAlthough the FAR was brief, the presentation of the four contextual areas was relevant to the majority of administrators and prompted them to plan or to take action within their facility. <br /

    Dynamical Generation of Linear σ\sigma model SU(3) Lagrangian and Meson Nonet Mixing

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    This paper is the SU(3) extension of the dynamically generated SU(2) linear σ\sigma model Lagrangian worked out previously using dimensional regularization. After discussing the quark-level Goldberger-Treiman relations for SU(3) and the related gap equations, we dynamically generate the meson cubic and quartic couplings. This also constrains the meson-quark coupling constant to g=2π/3g=2\pi/\sqrt3 and determines the SU(3) scalar meson masses in a Nambu-Jona-Lasinio fashion. Finally we dynamically induce the U(3) pseudoscalar and scalar mixing angles in a manner compatible with data.Comment: 19 printed pages, requires plain Tex, now published in IJMPA 13, 657 (1998

    Measuring the context of care in an Australian acute care hospital: a nurse survey

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    BACKGROUND: This study set out to achieve three objectives: to test the application of a context assessment tool in an acute hospital in South Australia; to use the tool to compare context in wards that had undergone an evidence implementation process with control wards; and finally to test for relationships between demographic variables (in particular experience) of nurses being studied (n = 422) with the dimensions of context. METHODS: The Alberta Context Tool (ACT) was administered to all nursing staff on six control and six intervention wards. A total of 217 (62%) were returned (67% from the intervention wards and 56% from control wards). Data were analysed using Stata (v9). The effect of the intervention was analysed using nested (hierarchical) analysis of variance; relationships between nurses' experience and context was examined using canonical correlation analysis. RESULTS: Results confirmed the adaptation and fit of the ACT to one acute care setting in South Australia. There was no difference in context scores between control and intervention wards. However, the tool identified significant variation between wards in many of the dimensions of context. Though significant, the relationship between nurses' experience and context was weak, suggesting that at the level of the individual nurse, few factors are related to context. CONCLUSIONS: Variables operating at the level of the individual showed little relationship with context. However, the study indicated that some dimensions of context (e.g., leadership, culture) vary at the ward level, whereas others (e.g., structural and electronic resources) do not. The ACT also raised a number of interesting speculative hypotheses around the relationship between a measure of context and the capability and capacity of staff to influence it.Timothy J. Schultz and Alison L. Kitso

    Data for improvement and clinical excellence: protocol for an audit with feedback intervention in long-term care

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    <p>Abstract</p> <p>Background</p> <p>There is considerable evidence about the effectiveness of audit coupled with feedback, although few audit with feedback interventions have been conducted in long-term care (LTC) settings to date. In general, the effects have been found to be modest at best, although in settings where there has been little history of audit and feedback, the effects may be greater, at least initially. The primary purpose of the Data for Improvement and Clinical Excellence (DICE) Long-Term Care project is to assess the effects of an audit with feedback intervention delivered monthly over 13 months in four LTC facilities. The research questions we addressed are:</p> <p indent="1">1. What effects do feedback reports have on processes and outcomes over time?</p> <p indent="1">2. How do different provider groups in LTC and home care respond to feedback reports based on data targeted at improving quality of care?</p> <p>Methods/design</p> <p>The research team conducting this study comprises researchers and decision makers in continuing care in the province of Alberta, Canada. The intervention consists of monthly feedback reports in nine LTC units in four facilities in Edmonton, Alberta. Data for the feedback reports comes from the Resident Assessment Instrument Minimum Data Set (RAI) version 2.0, a standardized instrument mandated for use in LTC facilities throughout Alberta. Feedback reports consist of one page, front and back, presenting both graphic and textual information. Reports are delivered to all staff working in the four LTC facilities. The primary evaluation uses a controlled interrupted time series design both adjusted and unadjusted for covariates. The concurrent process evaluation uses observation and self-report to assess uptake of the feedback reports. Following the project phase described in this protocol, a similar intervention will be conducted in home care settings in Alberta. Depending on project findings, if they are judged useful by decision makers participating in this research team, we plan dissemination and spread of the feedback report approach throughout Alberta.</p

    Self-Efficacy, Problem Solving, and Social-Environmental Support Are Associated With Diabetes Self-Management Behaviors

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    OBJECTIVE — To evaluate associations between psychosocial and social-environmental variables and diabetes self-management, and diabetes control. RESEARCH DESIGN AND METHODS — Baseline data from a type 2 diabetes self-management randomized trial with 463 adults having elevated BMI (M 34.8 kg/m2) were used to investigate relations among demographic, psychosocial, and social-environmental variables; dietary, exercise, and medication-taking behaviors; and biologic outcomes. RESULTS — Self-efficacy, problem solving, and social-environmental support were indepen-dently associated with diet and exercise, increasing the variance accounted for by 23 and 19%, respectively. Only diet contributed to explained variance in BMI ( 0.17, P 0.0003) and self-rated health status ( 0.25, P 0.0001); and only medication-taking behaviors contrib-uted to lipid ratio (total–to–HDL) (0.20, P 0.0001) and A1C (0.21, P 0.0001). CONCLUSIONS — Interventions should focus on enhancing self-efficacy, problem solving, and social-environmental support to improve self-management of diabetes. Diabetes Care 33:751–753, 2010 D iabetes management requires coor-dination between the patient andthe primary care team. Given the lifestyle changes required for self-management success, patient, social, and environmental factors, including health care (1) and community support (2), are increasingly recognized as important. Un-derstanding relations among demo-graphic, psychosocial, and social-environmental variables, and multiple health risk behaviors is critical to devel-oping interventions that will sustain health behavior changes. RESEARCH DESIGN AND METHODS — Baseline data were col-lected as part of a patient randomized trial to evaluate the impact of an interactive, multimedia diabetes self-management program relative to “enhanced ” usual car
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