200 research outputs found

    Air Travel and Venous Thromboembolism: A Systematic Review

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    CONTEXT: Despite multiple attempts to document and quantify the danger of venous thromboembolism (VTE) following prolonged travel, there is still uncertainty about the magnitude of risk and what can be done to lower it. OBJECTIVES: To review the methodologic strength of the literature, estimate the risk of travel-related VTE, evaluate the efficacy of preventive treatments, and develop evidence-based recommendations for practice. DATA SOURCES: Studies identified from MEDLINE from 1966 through December 2005, supplemented by a review of the Cochrane Central Registry of Controlled Trials, the Database of Abstracts of Reviews of Effects, and relevant bibliographies. STUDY SELECTION: We included all clinical studies that either reported primary data concerning travel as a risk factor for VTE or tested preventive measures for travel-related VTE. DATA EXTRACTION AND ANALYSIS: Two reviewers reviewed each study independently to assess inclusion criteria, classify research design, and rate methodologic features. The effect of methodologic differences, VTE risk, and travel duration on VTE rate was evaluated using a logistic regression model. DATA SYNTHESIS: Twenty-four published reports, totaling 25 studies, met inclusion criteria (6 case-control studies, 10 cohort studies, and 9 randomized controlled trials). Method of screening for VTE [screening ultrasound compared to usual clinical care, odds ratio (OR) 390], outcome measure [all VTE compared to pulmonary embolism (PE) only, OR 21], duration of travel (<6 hours compared to 6–8 hours, OR 0.011), and clinical risk (“higher” risk travelers compared to “lower,” OR 3.6) were significantly related to VTE rate. Clinical VTE after prolonged travel is rare [27 PE per million flights diagnosed through usual clinical care, 0.05% symptomatic deep venous thrombosis (DVT) diagnosed through screening ultrasounds], but asymptomatic thrombi of uncertain clinical significance are more common. Graduated compression stockings prevented travel-related VTE (P < 0.05 in 4 of 6 studies), aspirin did not, and low-molecular-weight heparin (LMWH) showed a trend toward efficacy in one study. CONCLUSIONS: All travelers, regardless of VTE risk, should avoid dehydration and frequently exercise leg muscles. Travelers on a flight of less than 6 hours and those with no known risk factors for VTE, regardless of the duration of the flight, do not need DVT prophylaxis. Travelers with 1 or more risk factors for VTE should consider graduated compression stockings and/or LMWH for flights longer than 6 hours

    PTHrP Induces Autocrine/Paracrine Proliferation of Bone Tumor Cells through Inhibition of Apoptosis

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    Giant Cell Tumor of Bone (GCT) is an aggressive skeletal tumor characterized by local bone destruction, high recurrence rates and metastatic potential. Previous work in our lab has shown that the neoplastic cell of GCT is a proliferating pre-osteoblastic stromal cell in which the transcription factor Runx2 plays a role in regulating protein expression. One of the proteins expressed by these cells is parathryroid hormone-related protein (PTHrP). The objectives of this study were to determine the role played by PTHrP in GCT of bone with a focus on cell proliferation and apoptosis. Primary stromal cell cultures from 5 patients with GCT of bone and one lung metastsis were used for cell-based experiments. Control cell lines included a renal cell carcinoma (RCC) cell line and a human fetal osteoblast cell line. Cells were exposed to optimized concentrations of a PTHrP neutralizing antibody and were analyzed with the use of cell proliferation and apoptosis assays including mitochondrial dehydrogenase assays, crystal violet assays, APO-1 ELISAs, caspase activity assays, flow cytometry and immunofluorescent immunohistochemistry. Neutralization of PTHrP in the cell environment inhibited cell proliferation in a consistent manner and induced apoptosis in the GCT stromal cells, with the exception of those obtained from a lung metastasis. Cell cycle progression was not significantly affected by PTHrP neutralization. These findings indicate that PTHrP plays an autocrine/paracrine neoplastic role in GCT by allowing the proliferating stromal cells to evade apoptosis, possibly through non-traditional caspase-independent pathways. Thus PTHrP neutralizing immunotherapy is an intriguing potential therapeutic strategy for this tumor

    Number preferences in lotteries

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    We explore people's preferences for numbers in large proprietary data sets from two different lottery games. We find that choice is far from uniform, and exhibits some familiar and some new tendencies and biases. Players favor personally meaningful and situationally available numbers, and are attracted towards numbers in the center of the choice form. Frequent players avoid winning numbers from recent draws, whereas infrequent players chase these. Combinations of numbers are formed with an eye for aesthetics, and players tend to spread their numbers relatively evenly across the possible range

    Women and power: a theoretical approach using the example of copreneurial businesses

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    Despite the gradual recognition of strategic issues related to the integration of women into the economy, female entrepreneurship continues to receive little attention. Family business research attributes this situation to a lack of recognition given to the (decisive) role of women in these organizations. However, there is one type of family governance that formally acknowledges the man/woman combination: the copreneurial company. Copreneurs are couples who run a business together. This theoretical article highlights the role of women in the copreneurial context by distinguishing between formal and informal power- the latter being primarily held by women, but which is no less influential. The distribution of power reduces opposition costs between partners and the social costs of non-compliance, and improves the clarity of the entrepreneurial structure. Moreover, it increases satisfaction and a feeling of equality between the partners. These results can be generalized and shed light on the role of women in other entrepreneurial and social contexts. This article is published as part as part of a collection on the role of women in management and business

    Scholarly Impact: A Pluralistic Conceptualisation.

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    We critically assess a common approach to scholarly impact that relies almost exclusively on a single stakeholder (i.e., other academics). We argue that this approach is narrow and insufficient, and thereby threatens the credibility and long-term sustainability of the management research community. We offer a solution in the form of a broader and novel conceptual and measurement framework of scholarly impact: a pluralist perspective. It proposes actions that depart from the current win–lose and zero-sum views that lead to false trade-offs such as research versus practice, rigor versus relevance, and research versus service. Our proposed pluralist conceptualization can be instrumental in enabling business schools and other academic units to clarify their strategic direction in terms of which stakeholders they are trying to affect and why, the way future scholars are trained, and the design and implementation of faculty performance management systems. We argue that the adoption of a pluralist conceptualization of scholarly impact can increase motivation for engaged scholarship and design-science research that is more conducive to actionable knowledge as opposed to exclusive career-focused advances, enhance the relevance and value of our scholarship, and thereby help to narrow the much-lamented chasm between research and practice
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