956 research outputs found

    Phase I Clinical Trials in Acute Myeloid Leukemia: 23-Year Experience From Cancer Therapy Evaluation Program of the National Cancer Institute

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    Therapy for acute myeloid leukemia (AML) has largely remained unchanged, and outcomes are unsatisfactory. We sought to analyze outcomes of AML patients enrolled in phase I studies to determine whether overall response rates (ORR) and mortality rates have changed over time

    Social Entrepreneurship and Broader Theories: Shedding New Light on the “Bigger Picture”

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    This article documents the results of a research workshop bringing together six perspectives on social entrepreneurship. The idea was to challenge existing concepts of the economy, the firm, and entrepreneurship in order to shed new light on social entrepreneurship and on our existing theoretical frameworks. The first two contributions use a macro-perspective and discuss the notion of adaptive societies and the tragedies of disharmonization, respectively. Taking a management perspective, the next two focus on the limits of conventional assumptions in management theory, particularly human capital theory and resource-based view. The final two contributions follow an entrepreneurship perspective highlighting the usefulness of mobilization theory and the business model lens to social entrepreneurship. Despite this diversity, all contributions share the fact that they challenge narrow definitions of the unit of analysis in social entrepreneurship; they illustrate the aspect of social embeddedness, and they argue for an open-but-disciplined diversity of theories in social entrepreneurship research

    Position-sensitive detection of ultracold neutrons with an imaging camera and its implications to spectroscopy

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    Position-sensitive detection of ultracold neutrons (UCNs) is demonstrated using an imaging charge-coupled device (CCD) camera. A spatial resolution less than 15 μ\mum has been achieved, which is equivalent to an UCN energy resolution below 2 pico-electron-volts through the relation δE=m0gδx\delta E = m_0g \delta x. Here, the symbols δE\delta E, δx\delta x, m0m_0 and gg are the energy resolution, the spatial resolution, the neutron rest mass and the gravitational acceleration, respectively. A multilayer surface convertor described previously is used to capture UCNs and then emits visible light for CCD imaging. Particle identification and noise rejection are discussed through the use of light intensity profile analysis. This method allows different types of UCN spectroscopy and other applications.Comment: 12 figures, 28 pages, accepted for publication in NIM

    Franchising as a Strategy for Combining Small and Large Group Advantages (Logics) in Social Entrepreneurship:A Hayekian Perspective

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    This article develops a Hayekian perspective on social franchising that distinguishes between the end-connected logic of the small group and the rule-connected logic of the big group. Our key claim is that mission-driven social entrepreneurs often draw on the small-group logic when starting their social ventures and then face difficulties when the process of scaling shifts their operations toward a big-group logic. In this situation, social franchising offers a strategy to replicate the small group despite systemwide scaling, to mobilize decentrally accessible social capital, and to reduce agency costs through mechanisms of self-selection and self-monitoring. By employing a Hayekian perspective, we are thus able to offer an explanation as to why social franchising is a suitable scaling strategy for some social entrepreneurship organizations and not for others. We illustrate our work using the Ashoka Fellow Wellcome

    Measurement of the neutron lifetime using an asymmetric magneto- gravitational trap and in situ detection

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    The precise value of the mean neutron lifetime, τn\tau_n, plays an important role in nuclear and particle physics and cosmology. It is a key input for predicting the ratio of protons to helium atoms in the primordial universe and is used to search for new physics beyond the Standard Model of particle physics. There is a 3.9 standard deviation discrepancy between τn\tau_n measured by counting the decay rate of free neutrons in a beam (887.7 ±\pm 2.2 s) and by counting surviving ultracold neutrons stored for different storage times in a material trap (878.5±\pm0.8 s). The experiment described here eliminates loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls and neutrons in quasi-stable orbits rapidly exit the trap. As a result of this approach and the use of a new in situ neutron detector, the lifetime reported here (877.7 ±\pm 0.7 (stat) +0.4/-0.2 (sys) s) is the first modern measurement of τn\tau_n that does not require corrections larger than the quoted uncertainties.Comment: 9 pages, 3 figures, 2 table

    School librarians as literacy educators within a complex role

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    Librarians in schools are expected to play an important role as literacy educators, and have a positive impact on young people’s literacy learning. However in the context of their diverse workload, relatively little is known about how this aspect of their role sits within its competing demands, and the exact scope of the literacy educator requirements. Using a hybrid approach to content analysis, this article analyses 40 recent job description documents to identify the nature and prevalence of different aspects of the role, and to explore the literacy educator aspect of this profession. Findings suggest that while the literacy educator aspect is one of the most common role requirements, it sits within a complex workload, and the literacy educator aspect is itself multi-faceted and demanding
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