Constant propellant use rendezvous scenario across a launch window for refueling missions

Active rendezvous of an unmanned spacecraft with the Space Transportation System (STS) Shuttle for refueling missions is investigated. The operational constraints facing both the maneuvering spacecraft and the Shuttle during a rendezvous sequence are presented. For example, the user spacecraft must arrive in the generic Shuttle control box at a specified time after Shuttle launch. In addition, the spacecraft must be able to initiate the transfer sequence from any point in its orbit. The standard four-burn rendezvous sequence, consisting of two Hohmann transfers and an intermediate phasing orbit, is presented as a low-energy solution for rendezvous and retrieval missions. However, for refueling missions, the Shuttle must completely refuel the spacecraft and return to Earth with no excess fuel. This additional constraint is not satisfied by the standard four-burn sequence. Therefore, a variation of the four-burn rendezvous, the constant delta-V scenario, was developed to satisfy the added requirement

Launch COLA Operations: An Examination of Data Products, Procedures, and Thresholds

NASA GSFC and KSC, acting in response to headquarters NASA direction, performed a year-long study of launch collision avoidance (LCOLA) operations in order to determine and recommend best risk assessment and mitigation practices. The following condenses the findings and recommendations of the study into one short summary, a more expanded version of which appears as Section 10

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Book reviews including 'Piccola storia della Grande Guerra (Little history of the Great War)', by Angelo Ventrone

Borden Painter reviews the book 'Storia della santita nel cristianesimo occidentale', edited by Anna Benvenuti et al., Rome: Viella, 2005. Joseph P. Cosco reviews the book 'Rome in America: transnational Catholic ideology from the Risorgimento to Fascism', by Peter R. D'Agostino, Chapel Hill, North Carolina: University of North Carolina Press, 2004. Roberto M. Dainotto reviews the book 'Between salt water and holy water: a history of southern Italy', by Tommaso Astarita, New York: Norton, 2005. Richard Drake reviews the book 'Napoli 1799 fra storia e storiografia: atti del Convegno Internazionale Napoli, 21-24 Gennaio 1999', edited by Anna Maria Rao, Naples: Vivarium, 2002. Axel Koerner reviews the book 'Scene di fine ottocento: l'Italia fin de siecle a teatro', edited by Carlotta Sorba, Rome: Carocci Editore, 2004. Matteo Pratelli reviews the book 'Piccola storia della Grande Guerra', by Angelo Ventrone, Rome: Donzelli, 2005. H. James Burgwyn reviews the book 'L'Italia e l'Europa orientale: diplomazia culturale e propaganda 1918-1943', by Stefano Santoro, Milan: Franco Angeli, 2005. Steven F. White reviews the book 'Luigi sturzo e la democrazia nella prospettiva del terzo millennio: atti del Seminario Internazionale, Erice, 7-11 Ottobre 2000', edited by Eugenio Guccione, Florence: Leo S. Olschki Editore, 2004. Marta Petrusewicz reviews the book 'Banchieri-imprenditori nel mezzogiorno: la Banca di Calabria (1910-39)', by Maria Gabriella Rienzo, Rome: Donzelli Editore, 2004. Rachel Eden Black reviews the book 'Gli italiani negli Stati Uniti del XX secolo', by Anna Ferro and Matteo Pretelli, Rome: Centro Studi Emigrazione Roma, 2005. Maura Hametz reviews the book 'Jews in Italy under Fascist and Nazi rule', edited by Joshua D. Zimmerman, Cambridge: Cambridge University Press, 2005. Cathie Carmichael reviews the book 'A tragedy revealed: the story of Italians from Istria, Dalmatia and Venezia Giulia 1943-56', by Arrigo Petacco (translated by Konrad Eisenbichler), Toronto: Toronto University Press, 2005. Luigi Fontanella reviews the book 'Parole e sangue', by Arturo Giovannitti, Isernia: Iannone Editore, 2005

Narrative Experiences of History and Complex Systems

The chapter considers elements at play in the establishment of our current historical knowledge. Looking at past events as complex adaptive systems, it demonstrates why the current mediation of history is oversimplified. By formulating the possibility of a complex narrative matrix (environment), it explores its potential in offering both an archive of evidence drawn from multiple agents, and presenting the evolving relationship between them in time. This matrix aligns itself with a simulation of a CAS, the primary interest being the VR matrix' ability to be both an interactive interface enabling exploration of the evidential material from different points of access, and a construction able to reveal its procedural work; a dynamic that elicits the creation of meaning by including the reasoning behind the chosen archival material, the product of the process, and the process itself

Rivaroxaban with or without aspirin in stable cardiovascular disease

BACKGROUND: We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. METHODS: In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months. RESULTS: The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P<0.001; z=−4.126), but major bleeding events occurred in more patients in the rivaroxaban-plus-aspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; P<0.001). There was no significant difference in intracranial or fatal bleeding between these two groups. There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group. CONCLUSIONS: Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events