911 research outputs found

    Drogue Parachute Effects on the Orion Crew Module Stability

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    A forced oscillation test of the Orion Crew Module (CM) was conducted in the Langley 20-Foot Vertical Spin Tunnel. The objective of the test was to quantify the rate damping characteristics of the CM-drogue chute system. Numerous configurations were tested to measure the influence of the chutes on the CM dynamic aerodynamics and, conversely, the influence of the CM on drogue performance. Results show that the CM-drogue system is well-damped at all combinations of frequency, amplitude, and Strouhal number. The wake of the CM significantly reduces the drogue chute riser line force, and the drogues have little upstream influence on the CM aerodynamics. These results are being used to improve simulation model fidelity of CM flight with drogues deployed, which has been identified by the project as key to a successful Orion Critical Design Review

    Testing of Noodle Creek Site 41JS102 Jones County, Texas

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    Staff Archeologists from the Environmental Affairs Division of Texas Department of Transportation discovered buried cultural resources that constitute archeological site 41JS102, in June and July 2001 at the proposed location of a bridge replacement over Noodle Creek in Jones County, Texas. Shovel testing and backhoe trenching revealed cultural material at 65 cm below the surface. Following this discovery the Texas Department of Transportation made recommendations to the Texas Historical Commission to assess site 41JS 102 and they concurred. In September 2001 archeologists from the Texas Department of Transportation initiated the site assessment phase. Landowner complications halted that work before completion. Subsequently, TRC Environmental was provided a Work Authorization under an existing general services contract to complete the assessment of 41JS102 in December 2001. The fieldwork consisted of the hand excavation and documentation of eight 1 by 1 m test units and the digging and documenting of six backhoe trenches. Limited and scattered historic artifacts were recovered from the upper parts of the two alluvial terraces (T0 and T1). A prehistoric component with quantities of lithic debitage and sparse burned rocks, limited stone tools and mussel shells, and one possible cultural feature were encountered in a sloping, but well defined 10 to 15 cm thick zone in the T1 deposits. The Principal Investigator recommended prehistoric site 4 1JS102 was eligible for inclusion in the National Register of Historic Places and as a State Archeological Landmark. However, the staff at Texas Department of Transportation disagreed with that recommendation and presented an opposing case to the Texas Historical Commission who concurred with the Texas Department of Transportation\u27s recommendations. Consequently, no further archeological investigations will occur prior to the proposed development

    Electronic Consultation at the National Assembly for Wales

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    Significant developments are occurring in the domain of electronic government within the UK – the use of ICT to enable re-structuring of governmental processes. In this paper we look at that subset of e-Government known as electronic democracy. In particular, we describe how electronic consultation, an important facet of electronic democracy, is being used to procure ideas from partnership organisations and citizenry in relation to the policy formulation processes at a devolved regional assembly in the UK – the National Assembly for Wales (NAfW). We utilise a process model of governance focused around the concept of the policy cycle. This process is currently being enabled at the NAfW through the development of a series of bespoke ICT systems. Such forms of ICT innovation are seen by many to be significant ways in which government may re-engage with its populace, address issues of social exclusion in the area of democratic participation and generally re-energise the democratic process

    Beyond Access: Bridging the Digital Divide

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    This paper describes the theoretical underpinnings of an ongoing research project that is examining the relationship between e-Democracy and the ‘digital divide’. The literature surrounding the Digital Divide is reviewed, and the importance of equitable physical access to ICTs in the drive to bridge the issue of social exclusion examined. It is argued that any discussion of the phenomenon of the digital divide must look beyond equitable physical access and take into consideration issues mentioned separately in the literature – ‘real access’, ‘reach’ and ‘socially responsible connectivity’

    An integrated biochemical prediction model of all-cause mortality in patients undergoing lower extremity bypass surgery for advanced peripheral artery disease

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    BackgroundPatients with advanced peripheral artery disease (PAD) have a high prevalence of cardiovascular (CV) risk factors and shortened life expectancy. However, CV risk factors poorly predict midterm (<5 years) mortality in this population. This study tested the hypothesis that baseline biochemical parameters would add clinically meaningful predictive information in patients undergoing lower extremity bypass operations.MethodsThis was a prospective cohort study of patients with clinically advanced PAD undergoing lower extremity bypass surgery. The Cox proportional hazard model was used to assess the main outcome of all-cause mortality. A clinical model was constructed with known CV risk factors, and the incremental value of the addition of clinical chemistry, lipid assessment, and a panel of 11 inflammatory parameters was investigated using the C statistic, the integrated discrimination improvement index, and Akaike information criterion.ResultsThe study monitored 225 patients for a median of 893 days (interquartile range, 539-1315 days). In this study, 50 patients (22.22%) died during the follow-up period. By life-table analysis (expressed as percent surviving ± standard error), survival at 1, 2, 3, 4, and 5 years, respectively, was 90.5% ± 1.9%, 83.4% ± 2.5%, 77.5% ± 3.1%, 71.0% ± 3.8%, and 65.3% ± 6.5%. Compared with survivors, decedents were older, diabetic, had extant coronary artery disease, and were more likely to present with critical limb ischemia as their indication for bypass surgery (P < .05). After adjustment for the above, clinical chemistry and inflammatory parameters significant (hazard ratio [95% confidence interval]) for all-cause mortality were albumin (0.43 [0.26-0.71]; P = .001), estimated glomerular filtration rate (0.98 [0.97-0.99]; P = .023), high-sensitivity C-reactive protein (hsCRP; 3.21 [1.21-8.55]; P = .019), and soluble vascular cell adhesion molecule (1.74 [1.04-2.91]; P = .034). Of the inflammatory molecules investigated, hsCRP proved most robust and representative of the integrated inflammatory response. Albumin, eGFR, and hsCRP improved the C statistic and integrated discrimination improvement index beyond that of the clinical model and produced a final C statistic of 0.82.ConclusionsA risk prediction model including traditional risk factors and parameters of inflammation, renal function, and nutrition had excellent discriminatory ability in predicting all-cause mortality in patients with clinically advanced PAD undergoing bypass surgery

    Law vs. War: Competing Approaches to Fighting Terrorism

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    The authors address one of the fundamental assumptions underlying the conduct of the War on Terrorism - the nature of our enemy, whether perpetrators of terrorist activities are criminals or soldiers (combatants). Although the United States recognizes that terrorist acts are certainly illegal, it has chosen to treat perpetrators as combatants; but much of the world, including many of our traditional allies, have opted for a purely legalistic approach. Disagreement about assumptions is not the only basis for divergent policies for confronting terrorism, but certainly explains much of our inability to agree on strategies to overcome what we recognize as a serious common and persistent international problem. Their insights into how our respective cultures and histories influence our definitions, assumptions, and subsequent policy decisions can assist us to respect and learn from competing strategies. They correctly surmise that our current international struggle is too important for us to ignore assumptions underlying our own and competing ideas.https://press.armywarcollege.edu/monographs/1740/thumbnail.jp

    Overview of Dynamic Test Techniques for Flight Dynamics Research at NASA LaRC (Invited)

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    An overview of dynamic test techniques used at NASA Langley Research Center on scale models to obtain a comprehensive flight dynamics characterization of aerospace vehicles is presented. Dynamic test techniques have been used at Langley Research Center since the 1920s. This paper will provide a partial overview of the current techniques available at Langley Research Center. The paper will discuss the dynamic scaling necessary to address the often hard-to-achieve similitude requirements for these techniques. Dynamic test techniques are categorized as captive, wind tunnel single degree-of-freedom and free-flying, and outside free-flying. The test facilities, technique specifications, data reduction, issues and future work are presented for each technique. The battery of tests conducted using the Blended Wing Body aircraft serves to illustrate how the techniques, when used together, are capable of characterizing the flight dynamics of a vehicle over a large range of critical flight conditions

    A single nucleotide polymorphism in the p27Kip1 gene is associated with primary patency of lower extremity vein bypass grafts

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    ObjectiveFactors responsible for the variability in outcomes after lower extremity vein bypass grafting (LEVBG) are poorly understood. Recent evidence has suggested that a single nucleotide polymorphism (SNP) in the promoter region of the p27Kip1 gene, a cell-cycle regulator, is associated with coronary in-stent restenosis. We hypothesized an association with vein graft patency.MethodsThis was a retrospective genetic association study nested within a prospective cohort of 204 patients from three referral centers undergoing LEVBG for claudication or critical ischemia. The main outcome measure was primary vein graft patency.ResultsAll patients were followed up for a minimum of 1 year with duplex graft surveillance (median follow-up, 893 days; interquartile range, 539-1315). Genomic DNA was isolated and SNP analysis for the p27Kip1-838C>A variants was performed. Allele frequencies were correlated with graft outcome using survival analysis and Cox proportional hazards modeling. The p27Kip1-838C>A allele frequencies observed were CA, 53%; CC, 30%; and AA, 17%, satisfying Hardy-Weinberg equilibrium. Race (P = .025) and history of coronary artery disease (P = .027) were different across the genotypes; all other baseline variables were similar. Primary graft patency was greater among patients with the -838AA genotype (75% AA vs 55% CA/CC at 3 years; P = .029). In a Cox proportional hazards model including age, sex, race, diabetes, critical limb ischemia, redo (vs primary) bypass, vein type, and baseline C-reactive protein level, the p27Kip1-838AA genotype was significantly associated with higher graft patency (hazard ratio for failure, 0.4; 95% confidence interval, 0.17-0.93). Genotype was also associated with early (0-1 month) changes in graft lumen diameter by ultrasound imaging.ConclusionsThese data suggest that the p27Kip1-838C>A SNP is associated with LEVBG patency and, together with previous reports, underscore a central role for p27Kip1 in the generic response to vascular injury
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