715 research outputs found

    The reality of employer engagement in work-based learning

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    Organization Learning: A Sociocognitive Model Of Strategic Management

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    The traditional view of strategic management suggests that the performance of the organization is dependent upon the fit between its strategy and the internal and external environment. However, this rational-analytic view neglects the critical question of how organizations learn about their environment and then act on the knowledge/understanding. This dissertation develops a sociocognitive model of strategic management which is rooted in an organization learning paradigm. The sociocognitive model acts as a framework for identifying points of leverage to improve an organization\u27s collective interpretation of the environment.;It is hypothesized that the ability to interpret complex, dynamic domains is likely to reside in a group of individuals with a high potential level of interpretation; that is, a group with diverse and complex schemas. Integration is, however, key to exploiting cognitive diversity within a group. Based on the level of potential interpretation and the degree of integration achieved by a group, four types of organization schema are proposed: Impoverished (low interpretation and integration), Contentious (high interpretation, low integration), Groupthink (low interpretation, high integration), and Productive (high interpretation and integration).;The model was applied to a debate in the strategic management literature: whether consensus on goals and/or means leads to better performance. The cognitive perspective provides a different interpretation of consensus, suggesting that previous research has not distinguished among Impoverished, Groupthink and Productive schemas.;A total of 398 graduates and undergraduates, randomly assigned to 70 groups, participated in the week long Markstrat simulation. Cause maps were elicited from the respondents for the purpose of measuring schema complexity and view divergence.;The results of the study supported the importance of integration. As well, a high level of potential interpretation without integration (Contentious groups) was consistently associated with extremely poor performance, as expected. The results suggest that while Productive groups had a high level of performance, it was difficult for groups to integrate their high level of diversity and complexity. Moreover, failing to do so led to very poor performance, as found in the Contentious groups. Overall, the results provided strong support for the model and for the use of cause mapping techniques to measure cognitive diversity

    Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis C

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    The cost-effectiveness of noninvasive tests (NITs) as alternatives to liver biopsy is unknown. We compared the cost-effectiveness of using NITs to inform treatment decisions in adult patients with chronic hepatitis C (CHC). We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes (quality-adjusted life-years; QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four treatment strategies: testing with NITs and treating patients with fibrosis stage ≥F2; testing with liver biopsy and treating patients with ≥F2; treat none; and treat all irrespective of fibrosis. We compared all NITs and tested the cost-effectiveness using current triple therapy with boceprevir or telaprevir, but also modeled new, more-potent antivirals. Treating all patients without any previous NIT was the most effective strategy and had an incremental cost-effectiveness ratio (ICER) of £9,204 per additional QALY gained. The exploratory analysis of currently licensed sofosbuvir treatment regimens found that treat all was cost-effective, compared to using an NIT to decide on treatment, with an ICER of £16,028 per QALY gained. The exploratory analysis to assess the possible effect on results of new treatments, found that if SVR rates increased to >90% for genotypes 1-4, the incremental treatment cost threshold for the "treat all" strategy to remain the most cost-effective strategy would be £37,500. Above this threshold, the most cost-effective option would be noninvasive testing with magnetic resonance elastography (ICER=£9,189). Conclusions: Treating all adult patients with CHC, irrespective of fibrosis stage, is the most cost-effective strategy with currently available drugs in developed countries. © 2014 The Authors

    Posttransplant lymphoproliferative disorders in neuronal xenotransplanted macaques

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    Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations that occur in the setting of depressed T-cell function due to immunosuppressive therapy used following solid organ transplantation, hematopoietic stem cell transplantation, and also xenotransplantation. In the present study, 28 immunosuppressed parkinsonian Macaca fascicularis were intracerebrally injected with wild-type or CTLA4-Ig transgenic porcine xenografts to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Nine of 28 (32%) immunosuppressed primates developed masses compatible with PTLD, located mainly in the gastrointestinal tract and/or nasal cavity. The masses were classified as monomorphic PTLD according to the World Health Organization classification. Immunohistochemistry and polymerase chain reaction (PCR) analyses revealed that the PTLDs were associated with macaca lymphocryptovirus as confirmed by double-labeling immunohistochemistry for CD20 and Epstein-Barr nuclear antigen 2 (EBNA-2), where the viral protein was located within the CD20+ neoplastic B cells. In sera from 3 distinct phases of the experimental life of the primates, testing by quantitative PCR revealed a progression of the viral load that paralleled the PTLD progression and no evidence of zoonotic transmission of porcine lymphotropic herpesvirus through xenoneuronal grafts. These data suggest that monitoring the variation of macaca lymphocryptovirus DNA in primates could be used as a possible early diagnostic tool for PTLD progression, allowing preemptive treatment such as immunosuppression therapy reduction

    Potential Environmental Impacts of Hydrogen-based Transportation and Power Systems

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    Hydrogen (H2) offers advantages as an energy carrier: minimal discharge of pollutants, production from multiple sources, increased thermodynamic efficiencies compared to fossil fuels, and reduced dependence on foreign oil. However, potential impacts from the H2 generation processes, transport and distribution of H2, and releases of H2 into the atmosphere have been proposed. The goal of this project was to analyze the effects of emissions of hydrogen, the six criteria pollutants and greenhouse gases on climate, human health, materials and structures. This project was part of a larger effort by DOE to assess the life-cycle costs and benefits and environmental impacts to inform decisions regarding future hydrogen research. Technical Approach: A modeling approach was developed and used to evaluate the potential environmental effects associated with the conversion of the on-road vehicle fleet from fossil-fuel vehicles to hydrogen fuel cell vehicles. GATOR-GCMOM was the primary tool used to predict atmospheric concentrations of gases and aerosols for selected scenarios. This model accounts for all feedbacks among major atmospheric processes based on first principles. The future scenarios and the emission rates selected for this analysis of hydrogen environmental effects are based on the scenarios developed by IPCC. The scenarios selected for the model simulations are a 2000 and 2050 A1B base cases, and a 2050 A1B case with hydrogen fuel cell vehicles (HFCVs). The hydrogen fuel cell scenario assumed conversion of 90% of fossil-fuel on-road vehicles (FFOV) in developed countries and 45% of FFOVs vehicles in other countries to HFCVs, with the H2 produced by steam-reforming of natural gas (SHFCVs). Simulations were conducted to examine the effect of converting the worldâÂÂs FFOVs to HFCVs, where the H2 is produced by wind-powered electrolysis (WHFCVs). In all scenarios a 3% leakage of H2 consumed was assumed. Two new models were developed that provide the ability to evaluate a wider range of conditions and address some of the uncertainties that exist in the evaluation of hydrogen emissions. A simplified global hydrogen cycle model that simulates hydrogen dynamics in the troposphere and stratosphere was developed. A Monte Carlo framework was developed to address hydrogen uptake variability for different types of ecosystems. Findings 1.Converting vehicles worldwide in 2050 to SHFCVs at 90% penetration in developed countries and 45% penetration in other countries is expected to reduce NOx, CO, CO2, CH4, some other organic gases, ozone, PAN, black carbon, and other particle components in the troposphere, but may increase some other organic gases, depending on emissions. Conversion to SHFCVs is also expected to cool the troposphere and warm the stratosphere, but to a lesser extent than WHFCVs. Finally, SHFCVs are expected to increase UTLS ozone while decreasing upper stratospheric ozone, but to a lesser extent than WHFCVs. 2.The predicted criteria pollutant concentrations from the GATOR-GCMOM simulations indicated that near-surface annual mean concentrations in the US are likely to increase from the 2000 base case to the 2050 A1B base case for CO2 and ozone due to the increased economic activity, but to decrease for CO, NO2, SO2, and PM10 due to improved pollution control equipment and energy efficiencies. The shift to SHFCVs in 2050 was predicted to result in decreased concentrations for all the criteria pollutants, except for SO2 and PM10. The higher predicted concentrations for SO2 and PM10 were attributed to increased emissions using the steam-reforming method to generate H2. If renewable methods such as wind-based electrolysis were used to generate H2, the emissions of SO2 and PM10 would be lower. 3.The effects on air quality, human health, ecosystem, and building structures were quantified by comparing the GATOR-GCMOM model output and accepted health and ecosystem effects levels and ambient air quality criteria. Shifting to HFCVs is expected to result in improved air quality and benefits to human health. Shifting to HFCVs is unlikely to result in damage to buildings. 4.Results are thought to be robust for larger leakage rates of H2 and for greater penetrations of HFCVs, since the controlling factor for stratospheric ozone impacts is the reduction in fossil-fuel greenhouse gases and the resulting surface cooling, which reduces water vapor emissions and stratospheric warming, which increases tropopause stability reducing water vapor transport to the stratosphere. 5.The supplemental modeling results were generally supportive of the results from the GATOR-GCMOM simulations, and recommendations for additional analyses were made. Extending the duration of the simulation to coincide with the time required for hydrogen mixing ratios to attain a steady state condition was recommended. Further evaluation of algorithms to describe hydrogen uptake in the model was also recommended
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