Development of A Commercial Expendable Launch Vehicle Industry

A ground rule in the development of the Shuttle was that expendable launch vehicles (ELV) would be phased out and eventually terminated and that the Shuttle would be the single transportation system for the nation. Subsequently, President Reagan announced a National Space Policy on July 4, 1982, which called for continuation of U.S. ELV activities until the Shuttle was fully operational. Several private firms expressed interest in providing ELV services on a commercial basis. This interest resulted in the 1983 Commercialization of Expendable Launch Vehicles Policy which laid the foundation for a U.S. commercial ELV industry. This policy declared that the U.S. Government fully endorsed and would facilitate commercial operations of ELV\u27s by the U.S. private sector in order to ensure a flexible and robust U.S. launch posture to maintain space transportation leadership. However, it also stated that the Shuttle would also be available to all authorized users. A National Space Strategy was issued in 1984, implementing the National Policy on Commercial Use of Space. This policy identified the encouragement of commercial ELV\u27s as one of the nation\u27s high priority national space goals. As a means of coordinating the development of commercial ELV operations, the 1984 Commercial Space Launch Act (Public Law 98-575) designated the Department of Transportation as the lead agency within the Federal Government for encouraging and facilitating commercial ELV activities by the U.S. private sector, as well as regulating those activities. This Act provides that the U.S. Government- will not subsidize the x commercial! zation of ELV\u27s, but will price the use of its facilities, equipment, and services consistent with the goal of encouraging viable commercial ELV activities

Problem gambling in early adulthood: a population-based study

The aims of this study were to investigate stability of problem gambling between 20 and 24 years of age, and the antecedents and consequences of problem gambling at age 20 years. Young adult participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) completed computer-administered gambling surveys on paper, or online. Responses to the Problem Gambling Severity Index (PGSI) were complete for 2624 participants at 20 years, and 1921 participants at 24 years. Responses were categorized into ‘non-problem’ (71–78%), ‘low-risk gambling’ (16–21%), ‘moderate-risk gambling’ (4–5.5%), and ‘problem gambling’ (1–1.5%). The overall frequency of moderate-risk/problem gambling varied little between age 20 and 24 years, and scratch cards, online betting and gambling were the most frequent activities. Problem gamblers at age 20 years had a history of hyperactivity and conduct problems in adolescence, high sensation seeking, and an external locus of control. They were more likely to have mothers who had problems with gambling, reported less parental supervision, and higher social media usage. Moderate-risk/problem gambling at age 20 years was associated with regular cigarette smoking, high levels of illicit drug use, and problematic use of alcohol at age 24 years. A significant minority of young adults (mainly males) showed problem gambling behaviours which appeared to be established by the age of 20 years and were associated with other potentially addictive behaviours

Improved PET/CT Respiratory Motion Compensation by Incorporating Changes in Lung Density

Positron emission tomography/computed tomography (PET/CT) lung imaging is highly sensitive to motion. Although several techniques exist to diminish motion artifacts, a few accounts for both tissue displacement and changes in density due to the compression and dilation of the lungs, which cause quantification errors. This article presents an experimental framework for joint activity image reconstruction and motion estimation in PET/CT, where the PET image and the motion are directly estimated from the raw data. Direct motion estimation methods for motion-compensated PET/CT are preferable as they require a single attenuation map only and result in optimal signal-to-noise ratio (SNR). Previous implementations, however, failed to address changes in density during respiration. We propose to account for such changes using the Jacobian determinant of the deformation fields. In a feasibility study, we demonstrate on a modified extended cardiac-torso (XCAT) phantom with breathing motion-where the lung density and activity vary-that our approach achieved better quantification in the lungs than conventional PET/CT joint activity image reconstruction and motion estimation that does not account for density changes. The proposed method resulted in lower bias and variance in the activity images, reduced mean relative activity error in the lung at the reference gate (-4.84% to -3.22%) and more realistic Jacobian determinant values

Gambling in young adults aged 17-24 years: a population-based study

A large contemporary UK cohort study, the Avon Longitudinal Study of Parents and Children, was used to investigate gambling behavior and to explore the antecedents of regular gambling in the 17–24-year age group. Participants completed computer-administered gambling surveys in research clinics, on paper, and online. The sample sizes were 3566 at age 17 years, 3940 at 20 years, and 3841 at 24 years; only 1672 completed all three surveys. Participation in gambling in the last year was reported by 54% of 17-year-olds, rising to 68% at 20 years, and 66% at 24 years, with little overall variance. Regular (weekly) gambling showed a strong gender effect, increasing among young men from 13% at 17 years to 18% at 20 years, and 17% at 24 years. Although gambling frequency increased between the ages of 17 and 20 years, gambling behaviors showed little variance between 20 and 24 years, except online gambling and betting on horseraces. The commonest forms of gambling were playing scratchcards, playing the lottery, and private betting with friends. Gambling on activities via the internet increased markedly between 17 and 24 years, especially among males. In the fully adjusted model, individual antecedents of regular gambling were being male, and having a low IQ, an external locus of control, and high sensation seeking scores. Parental gambling behavior and maternal educational background were associated with regular gambling in both sexes. Regular gambling was associated with smoking cigarettes and frequent and harmful use of alcohol, but no associations with depression were found

Iterative PET Image Reconstruction using Adaptive Adjustment of Subset Size and Random Subset Sampling

Statistical PET image reconstruction methods are often accelerated by the use of a subset of available projections at each iteration. It is known that many subset algorithms, such as ordered subset expectation maximisation, will not converge to a single solution but to a limit cycle. Reconstruction methods exist to relax the update step sizes of subset algorithms to obtain convergence, however, this introduces additional parameters that may result in extended reconstruction times. Another approach is to gradually decrease the number of subsets to reduce the effect of the limit cycle at later iterations, but the optimal iteration numbers for these reductions may be data dependent. We propose an automatic method to increase subset sizes so a reconstruction can take advantage of the acceleration provided by small subset sizes during early iterations, while at later iterations reducing the effects of the limit cycle behaviour providing estimates closer to the maximum a posteriori solution. At each iteration, two image updates are computed from a common estimate using two disjoint subsets. The divergence of the two update vectors is measured and, if too great, subset sizes are increased in future iterations. We show results for both sinogram and list mode data using various subset selection methodologies

Data relating to early child development in the Avon Longitudinal Study of Parents and Children (ALSPAC), their relationship with prenatal blood mercury and stratification by fish consumption.

As part of the Avon Longitudinal Study of Parents and Children (ALSPAC), measures of early child development were collected using both hands-on expert assessment (on a random 10% sub-sample) by trained psychologists at 18 months using the Griffiths Mental Development Scales (Extended 0–8 years) and from detailed questionnaires completed by the study mothers on the whole cohort using assessments based on the Denver Developmental Screening Test. The development determined by the psychologists on the 10% subsample showed a correlation of 0.49 (R. Wilson, 2003) [9] with the developmental level estimated from the maternal report. Maternal reports were used to determine the associations between prenatal blood mercury levels and scores of social achievement, fine motor skills, gross motor skills and communication at various preschool ages. (For results, please see doi:10.1016/j.neuro.2016.02.006 [1].

A Demonstration of STIR-GATE-Connection

We present the first open-source version of STIR-GATE-Connection, a project that aims to provide an easy-to-use pipeline to simulate realistic PET data using GATE, followed by quantitative reconstruction using STIR. Monte Carlo simulations and image reconstruction are powerful research tools for emission tomography that can assist with the design of new medical imaging devices as well as the evaluation of novel image reconstruction algorithms and various correction techniques. STIR-GATE-Connection is a collection of scripts that aid with the: (i) setup of a realistic GATE simulation of a voxelised phantom using a user selected scanner configuration, (ii) conversion of the output list mode data into STIR compatible sinograms, and (iii) computation of additive and multiplicative data corrections for Poisson image reconstruction using STIR. In this work, we demonstrate example usage of these steps. A public release of STIR-GATE-Connection, licensed under the Apache 2.0 License, can be downloaded at: http://www.github.com/UCL/STIR-GATE-Connection

Associations between prenatal mercury exposure and early child development in the ALSPAC study

AbstractIntroductionThere is evidence that high levels of mercury exposure to the pregnant woman can result in damage to the brain of the developing fetus. However there is uncertainty as to whether lower levels of the metal have adverse effects on the development of the infant and whether components of fish consumption and/or the selenium status of the woman is protective.MethodsIn this study we analysed data from the Avon Longitudinal Study of Parents and Children (ALSPAC) (n=2875–3264) to determine whether levels of total blood mercury of pregnant women collected in the first half of pregnancy are associated with the development of the offspring at ages 6, 18, 30 and 42 months. The developmental measures used maternal self-reported scales for individual types of development (fine and gross motor, social and communication skills) and total scores. Multiple and logistic regression analyses treated the outcomes both as continuous and as suboptimal (the lowest 15th centile). The statistical analyses first examined the association of prenatal mercury exposure with these developmental endpoints and then adjusted each for a number of social and maternal lifestyle factors; finally this model was adjusted for the blood selenium level.ResultsTotal maternal prenatal blood mercury and selenium ranged from 0.17 to 12.76 and 17.0 to 324μg/L respectively. We found no evidence to suggest that prenatal levels of maternal blood mercury were associated with adverse development of the child, even when the mother had consumed no fish during pregnancy. In general, the higher the mercury level the more advanced the development of the child within the range of exposure studied. For example, the fully adjusted effect sizes for total development at 6 and 42 months were +0.51 [95%CI +0.05, +1.00] and +0.43 [95%CI +0.08, +0.78] points per SD of mercury. For the risk of suboptimal development the ORs at these ages were 0.90 [95%CI 0.80, 1.02] and 0.88 [95%CI 0.77, 1.02]. In regard to the associations between blood mercury and child development there were no differences between the mothers who ate fish and those who did not, thus implying that the benefits were not solely due to the beneficial nutrients in fish.ConclusionsWe found no evidence of adverse associations between maternal prenatal blood mercury and child development between 6 and 42 months of age. The significant associations that were present were all in the beneficial direction

Les effets du bénévolat sur l?accès à l?emploi : une expérience contrôlée sur des jeunes qualifiés d?Ile-de-France

Accès à l?emploi, bénévolat, testing

“I was worried if I don’t have a broken leg they might not take it seriously”: Experiences of men accessing ambulance services for mental health and/or alcohol and other drug problems

Abstract Background A large proportion of ambulance callouts are for men with mental health and/or alcohol and other drug (AOD) problems, but little is known about their experiences of care. This study aimed to describe men's experiences of ambulance care for mental health and/or AOD problems, and factors that influence their care. Methods Interviews were undertaken with 30 men who used an ambulance service for mental health and/or AOD problems in Australia. Interviews were analysed using the Framework approach to thematic analysis. Results Three interconnected themes were abstracted from the data: (a) professionalism and compassion, (b) communication and (c) handover to emergency department staff. Positive experiences often involved paramedics communicating effectively and conveying compassion throughout the episode of care. Conversely, negative experiences often involved a perceived lack of professionalism, and poor communication, especially at handover to emergency department staff. Conclusion Increased training and organizational measures may be needed to enhance paramedics' communication when providing care to men with mental health and/or AOD problems