1,391 research outputs found

    Information Systems and Health Care VII - When Success Results in Failure: The Challenge of Extending the IT Infrastructure to Support Organ Procurement and Transplantation

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    Xpedite was a computer-based information system developed by the United Network for Organ Sharing (UNOS) to enhance organ procurement and placement from cadavers. Using state-of-the-art development approaches and technology at the time of its development, Xpedite was built around Lotus Notes, facsimile machines, and alphanumeric pagers. It was developed to integrate and streamline the collection, transfer, and exchange of data on available organs more fully. The concept was to shorten the time from organ availability (i.e., donor death) to transplant, thus reducing organ wastage. Xpedite met design and operational performance goals (i.e., a reduction in placement times and data errors), yet its operation was terminated after barely twenty-four months of operation. Adoption of the new technology throughout the transplant community was limited due to inexperience with integrated information technology systems and the resistance to change that accompanied Xpedite\u27s launch. The individual and organizational resistance was a surprise to UNOS. The technical and organizational lessons learned from this experience helped UNOS with developing subsequent information technology infrastructure components. The complexity of the technology support environment and low levels of user adoption for Xpedite ultimately led to an evolution beyond this tool, resulting in an Internet-based environment that would be more robust, easier to maintain, and better able to support user needs

    Unfolding of eigenvalue surfaces near a diabolic point due to a complex perturbation

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    The paper presents a new theory of unfolding of eigenvalue surfaces of real symmetric and Hermitian matrices due to an arbitrary complex perturbation near a diabolic point. General asymptotic formulae describing deformations of a conical surface for different kinds of perturbing matrices are derived. As a physical application, singularities of the surfaces of refractive indices in crystal optics are studied.Comment: 23 pages, 7 figure

    Transnational policy entrepreneurs and the cultivation of influence : individuals, organizations and their networks

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    The ‘policy entrepreneur’ concept arises from the Multiple Streams’ theory of agenda setting in Policy Studies. Through conceptual stretching’, the concept is extended to global policy dynamics. Unlike ‘advocacy networks’ and ‘norm entrepreneurs’, the discussion addresses the strategies of ‘insider’ or ‘near-governmental’ non-state actors. The analysis advances the policy entrepreneur concept in three directions. First, the discussion develops the transnational dimensions of this activity through a case study of International Crisis Group. Second, rather than focusing on charismatic individuals, the discussion emphasizes the importance of organizational resources and reputations for policy entrepreneurship and access into international policy communities. Organizations maintain momentum behind policy solutions and pressures for change over the long term when individuals retire or depart for other positions. Third, the discussion outlines four distinct entrepreneur strategies and techniques that both individuals and organizations cultivate and deploy to enhance their power and persuasion in global policy processes and politics

    Rigid Supersymmetric Theories in Curved Superspace

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    We present a uniform treatment of rigid supersymmetric field theories in a curved spacetime M\mathcal{M}, focusing on four-dimensional theories with four supercharges. Our discussion is significantly simpler than earlier treatments, because we use classical background values of the auxiliary fields in the supergravity multiplet. We demonstrate our procedure using several examples. For M=AdS4\mathcal{M}=AdS_4 we reproduce the known results in the literature. A supersymmetric Lagrangian for M=S4\mathcal{M}=\mathbb{S}^4 exists, but unless the field theory is conformal, it is not reflection positive. We derive the Lagrangian for M=S3×R\mathcal{M}=\mathbb{S}^3\times \mathbb{R} and note that the time direction R\mathbb{R} can be rotated to Euclidean signature and be compactified to §1\S^1 only when the theory has a continuous R-symmetry. The partition function on M=S3ק1\mathcal{M}=\mathbb{S}^3\times \S^1 is independent of the parameters of the flat space theory and depends holomorphically on some complex background gauge fields. We also consider R-invariant N=2\mathcal{N}=2 theories on S3\mathbb{S}^3 and clarify a few points about them.Comment: 26 pages, uses harvmac; v2 with added reference

    Outcomes and risks in palliative pancreatic surgery: an analysis of the German StuDoQ|Pancreas registry

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    BACKGROUND: Non-resectability is common in patients with pancreatic ductal adenocarcinoma (PDAC) due to local invasion or distant metastases. Then, biliary or gastroenteric bypasses or both are often established despite associated morbidity and mortality. The current study explores outcomes after palliative bypass surgery in patients with non-resectable PDAC. METHODS: From the prospectively maintained German StuDoQ|Pancreas registry, all patients with histopathologically confirmed PDAC who underwent non-resective pancreatic surgery between 2013 and 2018 were retrospectively identified, and the influence of the surgical procedure on morbidity and mortality was analyzed. RESULTS: Of 389 included patients, 127 (32.6%) underwent explorative surgery only, and a biliary, gastroenteric or double bypass was established in 92 (23.7%), 65 (16.7%) and 105 (27.0%). After exploration only, patients had a significantly shorter stay in the intensive care unit (mean 0.5 days [SD 1.7] vs. 1.9 [3.6], 2.0 [2.8] or 2.1 [2.8]; P < 0.0001) and in the hospital (median 7 days [IQR 4–11] vs. 12 [10–18], 12 [8–19] or 12 [9–17]; P < 0.0001), and complications occurred less frequently (22/127 [17.3%] vs. 37/92 [40.2%], 29/65 [44.6%] or 48/105 [45.7%]; P < 0.0001). In multivariable logistic regression, biliary stents were associated with less major (Clavien–Dindo grade ≥ IIIa) complications (OR 0.49 [95% CI 0.25–0.96], P = 0.037), whereas—compared to exploration only—biliary, gastroenteric, and double bypass were associated with more major complications (OR 3.58 [1.48–8.64], P = 0.005; 3.50 [1.39–8.81], P = 0.008; 4.96 [2.15–11.43], P < 0.001). CONCLUSIONS: In patients with non-resectable PDAC, biliary, gastroenteric or double bypass surgery is associated with relevant morbidity and mortality. Although surgical palliation is indicated if interventional alternatives are inapplicable, or life expectancy is high, less invasive options should be considered. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12893-022-01833-3

    Social mobilization against large hydroelectric dams: A comparison of Ethiopia, Brazil, and Panama

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    Large‐scale hydroelectric dams have—throughout their history—had adverse impacts on local population groups, natural resources, and entire eco‐systems furthering resistance and protest against them. In this paper, we aim to investigate the impact of social mobilization against large‐scale dams by considering political opportunity structures, actor constellations, and frames. We comparatively analyze three case studies in varying political systems, that is, Gibe III in Ethiopia, Belo Monte in Brazil, and Barro Blanco in Panama. Our investigation is based on field research in these countries comprising data collection of governmental reports, newspaper articles, materials published by civil society organizations, and semi‐structured interviews. The analysis reveals that the impact of mobilization against dams is certainly limited in contexts with authoritarian governments. In democratic contexts, the impact depends on the degree of external involvement, as well as the ability of movements to avoid fracture, especially in view of temporal dimensions of large infrastructure projects
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