Design, development and test of shuttle/Centaur G-prime cryogenic tankage thermal protection systems

The thermal protection systems for the shuttle/Centaur would have had to provide fail-safe thermal protection during prelaunch, launch ascent, and on-orbit operations as well as during potential abort. The thermal protection systems selected used a helium-purged polyimide foam beneath three rediation shields for the liquid-hydrogen tank and radiation shields only for the liquid-oxygen tank (three shields on the tank sidewall and four on the aft bulkhead). A double-walled vacuum bulkhead separated the two tanks. The liquid-hydrogen tank had one 0.75-in-thick layer of foam on the forward bulkhead and two layers on the larger area sidewall. Full scale tests of the flight vehicle in a simulated shuttle cargo bay that was purged with gaseous nitrogen gave total prelaunch heating rates of 88,500 Btu/hr and 44,000 Btu/hr for the liquid-hydrogen and -oxygen tanks, respectively. Calorimeter tests on a representative sample of the liquid-hydrogen tank sidewall thermal protection system indicated that the measured unit heating rate would rapidly decrease from the prelaunch rate of approx 100 Btu/hr/sq ft to a desired rate of less than 1.3 Btu/hr/sq ft once on orbit

Modeling in the Stateflow(Registered Trademark) Environment to Support Launch Vehicle Verification Testing for Mission and Fault Management Algorithms in the NASA Space Launch System

No abstract availabl

Calculating individual lifetime effective risk from initial mean glandular dose arising from the first screening mammogram

Objectives: To use the initial mean glandular dose (MGD) arising from the first screening mammogram to estimate the individual total screening lifetime effective risk. Methods: Organ doses from FFDM screening exposures (craniocaudal and mediolateral oblique for each breast) were measured using a simulated approach, with average breast thickness and adult ATOM phantoms, on 16 FFDM machines. Doses were measured using TLDs accommodated inside the ATOM phantom; examined breast MGD was calculated. Total effective risk during a client’s lifetime was calculated for 150 screening scenarios of different screening commencement ages and frequencies. For each scenario, a set of conversion factors were obtained to convert MGD values into total effective risk. Results: For the 16 FFDM machines, MGD contributes approximately 98% of total effective risk. This contribution is approximately constant for different screening regimes of different screening commencement ages. MGD contribution remains constant but the risk reduced because the radio-sensitivity of all body tissues, including breast tissue, reduces with age. Three sets of conversion factors were obtained for three screening frequencies (annual, biennial, triennial). Three relationship graphs between screening commencement age and total effective risk, as percentages of MGD, were created. Conclusions: Graphical representation of total risk could be an easy way to illustrate the total effective risk during a client’s lifetime. Screening frequency, commencement age, and MGD are good predictors for total effective risk generating more understandable data by clients than MGD

Attitudes to Three Weight Maintenance Strategies:A Qualitative Study

Weight loss maintenance can be difficult and ultimately unsuccessful, due to psychological, behavioural, social, and physiological influences. The present study investigated three strategies with the potential to improve weight maintenance success: daily weighing, missing an occasional meal, habitually changing high energy foods. The principal aim was to gain an understanding of attitudes to these strategies in participants who had recent experience of weight loss attempts, with or without maintenance. This was a qualitative study involving semi-structured interviews, with 20 participants aged 18–67 (twelve females), analysed using thematic analysis. Most participants disliked daily weighing and missing an occasional meal for long-term maintenance and were concerned about potential negative effects on mental health. All participants had experience of habitual changes to high energy foods and regarded this strategy as obvious and straightforward. Replacement of high energy foods was favoured over elimination. Participants preferred strategies that felt flexible, “normal” and intuitive and disliked those that were thought to have a negative impact on mental health. Further investigation is needed on whether concerns regarding mental health are well founded and, if not, how the strategies can be made more acceptable and useful

Environmental risk factors for canine atopic dermatitis: a retrospective large‐scale study in Labrador and golden retrievers

Background - canine atopic dermatitis (cAD) is one the most common and distressing skin disorders seen in dogs. It is characterised by dysfunction in the skin barrier, with a complex pathogenesis combining both genetic and environmental factors.Objectives - to evaluate associations between environmental factors and case-control status in two closely related, at-risk breeds, the Labrador and Golden retriever.Animals - 2,445 pet dogs, of which 793 were classed as cases (575 Labradors and218 Golden retrievers) and 1,652 as controls (1,120 Labradors and 532 Golden retrievers). Methods – case-control status was assigned based upon owner response to a standardised validated questionnaire. Retrospective data on rearing environment was collected via additional questions. Univariate and multivariate logistic regressions were utilised to evaluate associations between environmental factors and case-control status.Results - risk factors included being reared in an urban environment (not living currently in an urban environment), being male, being neutered, receiving flea control, and being allowed on upholstered furniture. Protective factors included living with other dogs (not cats) and walking in woodlands, fields or beaches. Additionally, amongst Labradors, chocolate coated dogs were at greater risk of having cAD than black or yellow coated dogs.Conclusions and clinical importance - This study is the largest of its kind to date to investigate the role of the environment in canine atopic dermatitis. Although precise triggers are unclear, this study contributes to those of earlier studies to highlight the protective role of a rural environment and highlights some novel associations with disease development

"She's a dog at the end of the day": guide dog owners' perspectives on the behaviour of their guide dog

A guide dog is a domestic dog (Canis familiaris) that is specifically educated to provide mobility support to a blind or visually impaired owner. Current dog suitability assessments focus on behavioural traits, including: trainability, reactivity or attention to environmental stimuli, low aggressiveness, fearfulness and stress behaviour, energy levels, and attachment behaviour. The aim of this study was to find out which aspects of guide dog behaviour are of key importance to guide dog owners themselves. Sixty-three semi-structured interview surveys were carried out with guide dog owners. Topics included the behaviour of their guide dog both within and outside their working role, and also focused on examples of behaviour which might be considered outside a guide dog owner’s typical expectations. Both positive and negative examples and situations were covered. This allowed for the discovery of new perspectives and emerging themes on living and working with a guide dog. Thematic analysis of the results reveals that a dog’s safe behaviour in the face of traffic was the most important positive aspect of a guide dog’s behaviour and pulling or high tension on the lead and /or harness was the most discussed negative aspect. Other aspects of guide dog behaviour were highlighted as particularly pleasing or disappointing by owners including attentiveness to the task, work, environment and owner; confidence in work and decision making (with confident dogs resulting in confident owners) obedience and control; calmness and locating objectives. The results reveal important areas of behaviour that are not currently considered priorities in guide dog assessments; these key areas were consistency of behaviour, the dog’s maturity and the dog’s behaviour in relation to children. The survey revealed a large range in what owners considered problematic or pleasing behaviours and this highlights the heterogeneity in guide dog owners and the potential multifarious roles of the guide dog. This study contributes to the literature on which behaviour is considered appropriate or inappropriate in dogs and on the nature of human-animal interactions

How did ocean warming affect Australian rainfall extremes during the 2010/2011 La Niña event?

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 9942–9951, doi:10.1002/2015GL065948.Extreme rainfall conditions in Australia during the 2010/2011 La Niña resulted in devastating floods claiming 35 lives, causing billions of dollars in damages, and far-reaching impacts on global climate, including a significant drop in global sea level and record terrestrial carbon uptake. Northeast Australian 2010/2011 rainfall was 84% above average, unusual even for a strong La Niña, and soil moisture conditions were unprecedented since 1950. Here we demonstrate that the warmer background state increased the likelihood of the extreme rainfall response. Using atmospheric general circulation model experiments with 2010/2011 ocean conditions with and without long-term warming, we identify the mechanisms that increase the likelihood of extreme rainfall: additional ocean warming enhanced onshore moisture transport onto Australia and ascent and precipitation over the northeast. Our results highlight the role of long-term ocean warming for modifying rain-producing atmospheric circulation conditions, increasing the likelihood of extreme precipitation for Australia during future La Niña events.Australian Research Council (ARC); ARC Centre of Excellence for Climate System Science; ARC Laureate Fellowship program; Penzance and John P. Chase Memorial Endowed Funds; Ocean Climate Change Institute at WHOI2016-05-1