1,159 research outputs found

    Uncertainty, Risk and Investment Decisions

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    Many government-sponsored applied research, development, demonstration and incentive programs are specifically undertaken to develop technology or create an environment that will lead to commercial ventures which will be in the public interest. The current Administration\u27s emphasis on commercialization has brought to the forefront joint endeavor or government/industry cooperative agreements and proposals for divesting operational capabilities to the private sector. The common thread between all these activities is the need for government agencies to plan and evaluate the private sector business ventures that may result. In the case of the joint endeavor agreements and divestiture situations, the evaluation of private sector business ventures is necessary to establish government negotiating positions. This paper briefly summarizes private sector financial performance measures and shows how government actions can affect private sector investment decisions through a reduction in perceived risk and shifting the burden of funding from the private sector to the public sector. Data is presented that illustrates the functional relationship betwen likelihood of investment and expected return on investment, risk, payback period and exposure. Finally, the required public sector financial analysis in support of joint endeavor agreements and divestiture situations is examined. Many questions and issues are raised with general procedures developed to answer a number of these

    Paper Session II-B - The Selection of a Launch Vehicle

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    The selection of a launch vehicle should not depend on any single vehicle attribute (i.e., price, reliability, availability, insurance rate, final payload placement accuracy, etc.), but rather on the effect of the interaction of multiple vehicle attributes in combination with payload configuration and sparing/maintenance strategy. For commercial organizations, selection decisions should be based on performance measures such as ROI and risk. For government operations, selections should be based on measures such as present value of life cycle cost in combination with availability constraints. Methods for analyzing launch vehicle and related choices are described together with parametric results illustrating important tradeoffs

    The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

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    These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology

    The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 2

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    These 92 papers comprise a peer-reviewed selection of presentations by authors from NASA, the Lunar and Planetary Institute (LPI), industry, and academia at the Second Conference on Lunar Bases and Space Activities of the 21st Century. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics included the following: (1) design and operation of transportation systems to, in orbit around, and on the Moon; (2) lunar base site selection; (3) design, architecture, construction, and operation of lunar bases and human habitats; (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology; (5) recovery and use of lunar resources; (6) environmental and human factors of and life support technology for human presence on the Moon; and (7) program management of human exploration of the Moon and space

    Significance of sex in achieving sustained remission in the consortium of rheumatology researchers of north america cohort of rheumatoid arthritis patients

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    Objective To determine whether men with rheumatoid arthritis (RA) are more likely to achieve remission compared to women. Methods RA patients enrolled in the Consortium of Rheumatology Researchers of North America (CORRONA) cohort between October 2001 and January 2010 were selected for the present analyses. Detailed clinical, demographic, and drug utilization data were available at enrollment (baseline) and at subsequent followup visits. We examined the influence of sex on the Clinical Disease Activity Index remission score (≤2.8) using sustained remission or point remission as the primary outcome measure in multivariate stepwise logistic regression models. We stratified the data by RA duration at baseline (≤2 years or >2 years) to investigate whether RA duration had differential effects on remission in men and women. Results A total of 10,299 RA patients (2,406 men and 7,893 women) were available for this study. In both early and established RA, women had more severe disease at baseline with worse disease activity measures, modified Health Assessment Questionnaire disability index score, pain on a visual analog scale, and depression. Women were also more likely to have been treated with disease‐modifying antirheumatic drugs and anti–tumor necrosis factor therapy compared to men. In the regression models, male sex was associated with sustained remission in early RA (odds ratio [OR] 1.38, 95% confidence interval [95% CI] 1.07–1.78, P = 0.01), but not in established RA. However, for point remission, an inverse association was observed with male sex in established RA (OR 0.65, 95% CI 0.48–0.87, P = 0.005) and not in early RA. Conclusion Within the large real‐life CORRONA cohort of RA patients, men were more likely to achieve sustained remission compared to women in early RA, although not in established RA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94462/1/21762_ftp.pd

    Polymer-based paclitaxel-eluting stents reduce in-stent neointimal tissue proliferation A serial volumetric intravascular ultrasound analysis from the TAXUS-IV trial

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    ObjectivesThe aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effects of polymer-based, paclitaxel-eluting stents on in-stent neointima formation and late incomplete stent apposition.BackgroundThe TAXUS-IV trial demonstrated that the slow-release, polymer-based, paclitaxel-eluting stent reduces angiographic restenosis and the need for repeat revascularization procedures. Serial IVUS studies reveal details of the pattern of vascular responses provoked by stent implantation that provide insight into device safety and efficacy.MethodsIn the TAXUS-IV trial, patients were randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). As part of a formal substudy, complete volumetric IVUS data were available in 170 patients, including 88 TAXUS patients and 82 controls, at implantation and at nine-month follow-up.ResultsNo baseline differences were present in the clinical characteristics or IVUS parameters between the control and TAXUS groups. At nine-month follow-up, IVUS lumen volumes were larger in the TAXUS group (123 ± 43 mm3vs. 104 ± 44 mm3, p = 0.005), due to a reduction in neointimal volume (18 ± 18 mm3vs. 41 ± 23 mm3, p < 0.001). Millimeter-by-millimeter analysis within the stent demonstrated uniform suppression of neointimal growth along the entire stent length. Late lumen loss was similar at the proximal edge of the stent between the two groups, and reduced with the TAXUS stent at the distal edge (p = 0.004). Incomplete stent apposition at nine months was observed in only 3.0% of control and 4.0% of TAXUS stents (p = 0.12).ConclusionsPolymer-based, paclitaxel-eluting TAXUS stents are effective in inhibiting neointimal tissue proliferation, and do not result in late incomplete stent apposition
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