Application of Risk Informed Decision Making to Highly Reliable Three Dimensionally Woven Thermal Protection System for Mars Sample Return

The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

Analysis of some global optimization algorithms for space trajectory design

In this paper, we analyze the performance of some global search algorithms on a number of space trajectory design problems. A rigorous testing procedure is introduced to measure the ability of an algorithm to identify the set of ²-optimal solutions. From the analysis of the test results, a novel algorithm is derived. The development of the novel algorithm starts from the redefinition of some evolutionary heuristics in the form of a discrete dynamical system. The convergence properties of this discrete dynamical system are used to derive a hybrid evolutionary algorithm that displays very good performance on the particular class of problems presented in this paper

What is the contribution of physician associates in hospital care in England? A mixed methods, multiple case study.

OBJECTIVES: To investigate the deployment of physician associates (PAs); the factors supporting and inhibiting their employment and their contribution and impact on patients' experience and outcomes and the organisation of services. DESIGN: Mixed methods within a case study design, using interviews, observations, work diaries and documentary analysis. SETTING: Six acute care hospitals in three regions of England in 2016-2017. PARTICIPANTS: 43 PAs, 77 other health professionals, 28 managers, 28 patients and relatives. RESULTS: A key influencing factor supporting the employment of PAs in all settings was a shortage of doctors. PAs were found to be acceptable, appropriate and safe members of the medical/surgical teams by the majority of doctors, managers and nurses. They were mainly deployed to undertake inpatient ward work in the medical/surgical team during core weekday hours. They were reported to positively contribute to: continuity within their medical/surgical team, patient experience and flow, inducting new junior doctors, supporting the medical/surgical teams' workload, which released doctors for more complex patients and their training. The lack of regulation and attendant lack of authority to prescribe was seen as a problem in many but not all specialties. The contribution of PAs to productivity and patient outcomes was not quantifiable separately from other members of the team and wider service organisation. Patients and relatives described PAs positively but most did not understand who and what a PA was, often mistaking them for doctors. CONCLUSIONS: This study offers new insights concerning the deployment and contribution of PAs in medical and surgical specialties in English hospitals. PAs provided a flexible addition to the secondary care workforce without drawing from existing professions. Their utility in the hospital setting is unlikely to be completely realised without the appropriate level of regulation and authority to prescribe medicines and order ionising radiation within their scope of practice

Absorbent products for urinary/faecal incontinence: a comparative evaluation of key product designs

Background: The UK health service, nursing homes and public spend around £94 million per year on incontinence pads (absorbent products) to contain urine and/or faeces, but the research base for making informed choices between different product designs is very weak.Objectives: The aim of this trial was to compare the performance and cost-effectiveness of the key absorbent product designs to provide a more solid basis for guiding selection and purchase.A further aim was to carry out the first stage in the development of a quality of life instrument for measuring the impact of absorbent product use on users' lives.Design: The work involved three clinical trials focusing on the three biggest market sectors. Each trial had a similar crossover design in which each participant tested all products within their group in random order.Settings, participants and methods: In Trial 1, 85 women with light urinary incontinence living in the community tested three products from each of the four design categories available (total of 12 test products): disposable inserts (pads); menstrual pads; washable pants with integral pad; and washable inserts. In Trial 2a, 85 moderate/heavily incontinent adults (urinary or urinary/faecal) living in the community (49 men and 36 women) tested three (or two) products from each of the five design categories available (total of 14 test products): disposable inserts (with mesh pants); disposable diapers (nappies); disposable pull-ups (similar to toddlers' trainer pants); disposable T-shaped diapers (nappies with waist-band); and washable diapers. All products were provided in a daytime and a (mostly more absorbent) night-time variant. In these first two trials, the test products were selected on the basis of data from pilot studies. In Trial 2b, 100 moderate/heavily incontinent adults (urinary or urinary/faecal) living in 10 nursing homes (27 men and 73 women) evaluated one product from each of the four disposable design categories from Trial 2a. Products were selected on the basis of product performance in Trial 2a and, again, daytime and night-time variants were provided. The first phase of work to develop a quality of life tool for measuring the impact of using different pad designs was carried out by interviewing participants from Trials 1 and 2a.Outcome measures: Product performance was characterised using validated questionnaires, which asked the participants (in Trials 1 and 2a) or carers (all participants in Trial 2b, except for the few who could report for themselves) to evaluate various aspects of pad performance (leakage, ease of putting on, discreetness, etc.) using a five-point scale (very good–very poor) at the end of the week (or 2 weeks for Trial 2b) of product testing. In addition, participants/carers were asked to save individual used pads in bags for weighing and to indicate the severity of any leakage from them on a three-point scale (none, a little, a lot). These data were used to determine differences in leakage performance. Numbers of laundry items and pads used were recorded to estimate costs, and skin health changes were recorded by the participant or by the researchers (Trial 2b). At the end of testing, participants were interviewed and ranked their preferences (with and without costs), stated the acceptability of each design (highly acceptable–totally unacceptable) and recorded their overall opinion on a visual analogue scale (VAS) of 0–100 points (worst design–best design). This VAS score was used with product costs to estimate cost-effectiveness. In addition, a timed pad changing exercise was conducted with 10 women from Trial 2b to determine any differences between product designs.Results: Results presented are for statistically and clinically significant findings.<br/

Enabling Entry Technologies for Ice Giant Missions

The highest priority science goals for Ice Giant missions are: 1) Interior structure of the Planet, and 2) Bulk composition that includes isotopes and noble gases. The interaction between the planetary interior and the atmosphere requires sustained global measurements. Noble gas and Isotope measurements require in situ measurement. Drag modulated aerocapture utilizing ADEPT offers more mass delivered to the Ice Giants than with propulsive orbit insertion. The Galileo Probe entered at a hot spot which created interpretation challenges. Juno is providing valuable orbital measurements, but without in situ measurements the story is incomplete. Planetary scientists interested in Ice Giant missions should perform mission design studies with these new Entry System technologies to assess the feasibility within the context of the international collaboration framework. A mission architecture that includes probe(s) along with an orbiting spacecraft can deploy the probes at the desired location while taking simultaneous measurements from orbit to provide invaluable data that can correlate both global and local measurements. Entry System Technologies currently being developed by NASA are poised to enable missions that position the Orbiter & Probes through drag modulated aerocapture (ADEPT), and HEEET enables the Probes to survive the extreme environments encountered for entry into the atmospheric interior

Changes in the prevalence and correlates of weight-control behaviors and weight perception in adolescents in the UK, 1986 to 2015

Importance: In the context of the growing prevalence of childhood obesity, behaviors aimed at weight loss and their psychological burden might be increasing. Objective: To investigate whether the prevalence of weight-control behaviors and weight perception, including their association with depressive symptoms, has changed in the 3 decades between 1986 and 2015. Design, Setting, and Participants: This study used data from repeated cross-sections from successive longitudinal birth cohort studies. These included general population samples of UK adolescents aged 14 to 16 years from 3 ongoing birth cohorts: the British Cohort Study 1970 (children born between April 5 and 11, 1970; data collected in 1986), the Avon Longitudinal Study of Parents and Children (mothers with expected delivery between April 1, 1991, and December 21, 1992; data collected in 2005), and the Millennium Cohort Study (children born between September 1, 2000, and January 11, 2002; data collected in 2015). A total of 22 503 adolescents with data available on at least 1 weight-control or weight-perception variable in midadolescence were included in the study. Data were analyzed from August 1, 2019, to January 15, 2020. Main Outcomes and Measures: Self-reported lifetime dieting and exercise for weight loss, current intentions about weight (doing nothing, lose weight, stay the same, gain weight), and weight perception (underweight, about the right weight, overweight) adjusted for body mass index. The secondary outcome was depressive symptoms. Exposures: The main exposure was time (ie, cohort); secondary exposures were weight-change behaviors and weight perception. Results: The study cohort included 22 503 adolescents (mean [SD] age, 14.8 [0.3] years; 12 061 girls [53.6%]; and 19 942 White individuals [89.9%]). A total of 5878 participants were from the British Cohort Study, 5832 were from the Avon Longitudinal Study of Parents and Children, and 10 793 were from the Millennium Cohort Study. In 2015, 4809 participants (44.4%) had dieted and 6514 (60.5%) had exercised to lose weight compared with 1952 (37.7%) and 344 (6.8%) in 1986. Furthermore, 4539 (42.2%) were trying to lose weight in 2015 compared with 1767 (28.6%) in 2005. Although girls were more likely to report these behaviors in all years, their prevalence increased more in boys over time (lifetime dieting in boys: odds ratio [OR], 1.79; 95% CI, 1.24-2.59; in girls: OR, 1.23; 95% CI, 0.91-1.66; currently trying to lose weight in boys: OR, 2.75; 95% CI, 2.38-3.19; in girls: OR, 1.70; 95% CI, 1.50-1.92). Adolescents also became more likely to overestimate their weight (boys describing themselves as overweight adjusting for body mass index, 2005 vs 1985 OR, 1.60; 95% CI, 1.17-2.19; 2015 vs 1985 OR, 1.36; 95% CI, 1.04-1.80; girls describing themselves as underweight, after adjusting for body mass index, 2015 vs 1986 OR, 0.51; 95% CI, 0.28-0.91). Girls who described themselves as overweight experienced increasingly greater depressive symptoms over time compared to girls who described their weight as about right (mean difference 1986, 0.32; 95% CI, 0.22-0.41; mean difference 2005, 0.33; 95% CI, 0.24-0.42; mean difference 2015, 0.56; 95% CI, 0.49-0.62). Conclusions and Relevance: These findings suggest that the growing focus on obesity prevention might have had unintended consequences related to weight-control behaviors and poor mental health. Public health campaigns addressing obesity should include prevention of disordered eating behaviors and be sensitive to negative impact on mental health

Diltiazem alone and combined with nitroglycerin: effect on normal and diseased human coronary arteries

The vasodilatory effect of diltiazem and nitroglycerin on the large epicardial coronary arteries was evaluated in 26 patients with coronary artery disease. The luminal area of a normal and a stenotic coronary artery was determined at rest, after intracoronary administration of diltiazem, during submaximal exercise as well as 5 min after 1·6 mg sublingual nitroglycerin using biplane quantitative coronary arteriography. Twelve patients with no pretreatment prior to the exercise test served as group 1 (controls) and 14 patients with intracoronary administration of 2 to 3 mg diltiazem prior to the exercise test as group 2. Normal vessel: In the control group luminal area increased significantly during exercise (+23%, P<0·01) and after sublingual administration of nitroglycerin (+40%, P<0·001). In group 2 luminal area increased after intracoronary administration of diltiazem (+19%, P<0·01), during bicycle exercise (+23%, P<0·001) and after sublingual administration of nitroglycerin (+39%, P<0·001). Stenotic vessel: In the control group luminal area decreased significantly (−29%, P<0·001) during bicycle exercise but increased after sublingual administration of nitroglycerin at the end of the exercise test (+12%, NS vs. rest). In group 2 intracoronary administration of diltiazem was associated with a mild increase in stenosis area (+11%, P<0·05). There was a further increase in stenosis area during bicycle exercise (+23%, P<0·001 vs. rest) and after sublingual nitroglycerin (+32%, P<0·001). Coronary vasodilation of the stenotic segment was, however, significantly more pronounced after sublingual nitroglycerin in group 2 than 1 (+32% versus 12%, P<0·05). Thus, it is concluded that diltiazem prevents exercise-induced coronary vasoconstriction of the stenotic vessel segment probably due to its direct vasorelaxing action on the smooth vasculature. Diltiazem combined with nitroglycerin elicits an additive effect on coronary vasodilation of the stenotic vessel segments but not on the normal coronary arteries. The exact mechanism of this additive effect is not clear but might be due to the combined action of the two vasoactive drugs with different mode of actio

Application of Risk Informed Decision Making to a Highly Reliable Three-Dimensionally Woven Thermal Protection System for Mars Sample Return

The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

Temporal variability and site specificity of thermomechanical weathering in a temperate climate

Thermomechanical processes caused by short- and long-term temperature fluctuations are a prevalent weathering mechanism on exposed rock walls. While many authors have explored the potential for thermomechanical weathering in alpine and polar regions, few have examined the effects of seasonality on weathering in temperate climates. This is pertinent as seasonal climatic conditions may influence both short-term temperature oscillations which produce incipient fractures and diurnal-to annual-scale cycles which propagate pre-existing fractures via thermal fatigue. In this study, three rock outcrops located along the Niagara Escarpment in Hamilton, Canada were monitored to examine changes in the thermal regime at the rock surface and within pre-existing fractures over a 1-year period. Temperature was sampled in 1-min intervals, providing data at a fine temporal resolution. Our unique dataset demonstrates that the rock surface and fracture experience minute-scale temperature oscillations which magnify over time. Longer-term temperature cycles during the year are superimposed upon minute- and diurnal-scale fluctuations which likely augment weathering potential. This produces considerable thermal stress over the year which we estimate to be on the order of 18 GPa at the rock surface and 8 GPa in fractures. We also observed diurnal reversals of the temperature gradient between the rock surface and fracture which may further amplify crack propagation. Seasonality and site-specific characteristics interact to modify different components of the rockwall thermal regime. Vegetation shading has seasonal and diurnal-scale impacts on the temperature gradient between the surface and fracture, and the amplitude of daily warming and cooling cycles. Aspect has a stronger influence on minute-scale temperature oscillations. Estimates of diurnal thermal stress indicate that the thermomechanical weathering potential is seasonally variable, but highest in the spring. Our findings demonstrate that in a temperate climate, rockwall thermal regimes experience variability across the gradient of temporal scale with strong seasonal effects

Services for people with young onset dementia: The 'Angela' project national UK survey of service use and satisfaction

Objectives: Young onset dementia is associated with distinctive support needs but existing research on service provision has been largely small scale and qualitative. Our objective was to explore service use, cost and satisfaction across the UK. Methods: Information about socio‐demographic characteristics, service use and satisfaction were gathered from people with young onset dementia (YOD) and/or a family member/supporter via a national survey. Results: Two hundred and thirty‐three responses were analysed. Diagnosis was most commonly received through a Memory Clinic or Neurology. The type of service delivering diagnosis impacted on post‐diagnostic care. Those diagnosed in specialist YOD services were more likely to receive support within the first 6 weeks and receive ongoing care in the service where they were diagnosed. Ongoing care management arrangements varied but generally care was lacking. Around 42% reported no follow‐up during 6‐weeks after diagnosis; over a third reported seeing no health professional within the previous 3 months; just over a third had a key worker and just under a third had a care plan. Satisfaction and quality of care were highest in specialist services. Almost 60% of family members spent over 5 h per day caring; median costs of health and social care, 3 months, 2018, were £394 (interquartile range £389 to 640). Conclusions: Variation across diagnostic and post‐diagnostic care pathways for YOD leads to disparate experiences, with specialist young onset services being associated with better continuity, quality and satisfaction. More specialist services are needed so all with YOD can access age‐appropriate care