Rendezvous strategy impacts on CTV avionics design, system reliability requirements, and available collision avoidance maneuvers

Rockwell International is conducting an ongoing program to develop avionics architectures that provide high intrinsic value while meeting all mission objectives. Studies are being conducted to determine alternative configurations that have low life-cycle cost and minimum development risk, and that minimize launch delays while providing the reliability level to assure a successful mission. This effort is based on four decades of providing ballistic missile avionics to the United States Air Force and has focused on the requirements of the NASA Cargo Transfer Vehicle (CTV) program in 1991. During the development of architectural concepts it became apparent that rendezvous strategy issues have an impact on the architecture of the avionics system. This is in addition to the expected impact on propulsion and electrical power duration, flight profiles, and trajectory during approach

The Stealth Biplane: a Proposal in Response to a Low Reynolds Number Station Keeping Mission

The Stealth Biplane is conceived and constructed to serve as a remotely piloted vehicle designed to navigate a low-level figure-eight course at a target Reynolds number of 100,000. This flight vehicle will combine the latest in lightweight radio controlled hardware in conjunction with current low Reynolds number aerodynamic research to demonstrate feasible operation in a variety of applications. These potential low Reynolds number applications include high altitude atmospheric sampling, search and rescue, and even law enforcement. Design specs and fabrication technique are discussed

Towards the selection of a final set of trials for the 2012 ENP gray whale implementation review

At the March 2012 Intersessional meeting of the AWMP Working Group in La Jolla,CA, a set of trials was agreed upon for consideration as part of the Eastern Pacific Gray Whale Implementation Review. Since then, progress has been made on conditioning that set of trials. An assessment of the preliminary conditioning results is presented here, with a focus on five trials that were not able to mimic the available data as well as the remaining trials. If any of these five trials is to be dropped from further consideration, there must be unanimous agreement within the Working Group for such

Exposure to, and searching for, information about suicide and self-harm on the Internet:Prevalence and predictors in a population based cohort of young adults

AbstractBackgroundThere is concern over the potential impact of the Internet on self-harm and suicidal behaviour, particularly in young people. However, little is known about the prevalence and patterns of suicide/self-harm related Internet use in the general population.MethodsCross sectional study of 3946 of the 8525 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) who were sent a self-report questionnaire including questions on suicide/self-harm related Internet use and self-harm history at age 21 years.ResultsSuicide/self-harm related Internet use was reported by 22.5% (886/3946) of participants; 11.9% (470/3946) had come across sites/chatrooms discussing self-harm or suicide, 8.2% (323/3946) had searched for information about self-harm, 7.5% (296/3946) had searched for information about suicide and 9.1% (357/3946) had used the Internet to discuss self-harm or suicidal feelings. Suicide/self-harm related Internet use was particularly prevalent amongst those who had harmed with suicidal intent (70%, 174/248), and was strongly associated with the presence of suicidal thoughts, suicidal plans, and history of self-harm. Sites offering help, advice, or support were accessed by a larger proportion of the sample (8.2%, 323/3946) than sites offering information on how to hurt or kill yourself (3.1%, 123/3946). Most individuals (81%) who had accessed these potentially harmful sites had also accessed help sites.Limitations(i) There were differences between questionnaire responders and non-responders which could lead to selection bias and (ii) the data were cross-sectional, and we cannot conclude that associations are causal.ConclusionsSuicide/self-harm related Internet use is common amongst young adults, particularly amongst those with suicidal thoughts and behaviour. Both harmful and helpful sites were accessed, highlighting that the Internet presents potential risks but also offers opportunities for suicide prevention

Using population attributable risk to choose HIV prevention strategies in men who have sex with men

<p>Abstract</p> <p>Background</p> <p>In Australia, HIV is concentrated in men who have sex with men (MSM) and rates have increased steadily over the past ten years. Health promotion strategies should ideally be informed by an understanding of both the prevalence of the factors being modified, as well as the size of the risk that they confer. We undertook an analysis of the potential population impact and cost saving that would likely result from modifying key HIV risk factors among men who have sex with men (MSM) in Sydney, Australia.</p> <p>Methods</p> <p>Proportional hazard analyses were used to examine the association between sexual behaviours in the last six months and sexually transmissible infections on HIV incidence in a cohort of 1426 HIV-negative MSM who were recruited primarily from community-based sources between 2001 and 2004 and followed to mid-2007. We then estimated the proportion of HIV infections that would be prevented if specific factors were no longer present in the population, using a population attributable risk (PAR) method which controls for confounding among factors. We also calculated the average lifetime healthcare costs incurred by the HIV infections associated with specific factors by estimating costs associated with clinical care and treatment following infection and discounting at 3% (1% and 5% sensitivity) to present value.</p> <p>Results</p> <p>Unprotected anal intercourse (UAI) with a known HIV-positive partner was reported by 5% of men, the hazard ratio (HR) was 16.1 (95%CI:6.4-40.5), the PAR was 34% (95%CI:24-44%) and the average lifetime HIV-related healthcare costs attributable to UAI with HIV-positive partners were $AUD102 million (uncertainty range:$93-114 m). UAI with unknown HIV status partners was reported by 25% of men, the HR was 4.4 (95%CI:1.8-11.2), the PAR was 33% (95%CI:26-42%) and the lifetime incurred costs were $AUD99 million. Anal warts prevalence was 4$AUD39 million.</p> <p>Conclusions</p> <p>Our analysis has found that although UAI with an HIV-positive sexual partner is a relatively low-prevalence behaviour (reported by 5% of men), if this behaviour was not present in the population, the number of infections would be reduced by one third. No other single behaviour or sexually transmissible infections contributes to a greater proportion of infections and HIV-related healthcare costs.</p

Really Underage Drinkers: Alcohol Use Among Elementary Students

Despite the current societal concern with underage drinking, little attention has been paid to alcohol use within the preadolescent population. This article presents the proceedings of a symposium held at the 2003 Research Society on Alcoholism meeting in Fort Lauderdale, Florida, that was organized and chaired by John E. Donovan. The intent of the symposium was to kick start research on alcohol use among elementary school children by reviewing what is known regarding drinking in childhood. Presentations included (1) The Epidemiology of Children's Alcohol Use, by John E. Donovan; (2) The Validity of Children's Self-Reports of Alcohol Use, by Sharon L. Leech; (3) Predicting Onset of Drinking From Behavior at Three Years of Age: Influence of Early Child Expectancies and Parental Alcohol Involvement Upon Early First Use, by Robert A. Zucker; and (4) Parent, Peer, and Child Risk Factors for Alcohol Use in Two Cohorts of Elementary School Children, by Carol J. Loveland-Cherry. Presentations indicated the need for better nationwide surveillance of children's experience with alcohol; suggested that children's reports of their use of alcohol tend to be reliable and valid; supported children's alcohol use schemas and parental drinking and alcoholism at child age three as independent predictors of early onset drinking; and showed that onset of drinking before fourth or fifth grade, peer pressure, and parental norms and monitoring predict elementary student alcohol use and misuse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65944/1/01.ALC.0000113922.77569.4E.pd

Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

EDITOR : an interactive interface to ILLIAC IV - ARPA network multispectral image processing systems / CAC No. 114

Includes bibliographic references (p. 15-16)