Data management study, volume 5. Appendix G - Contractor data package reliability assurance /RA/ Final report

Contractor data management package for system, subsystem, and component reliability assurance of Voyager spacecraf

I Love You, California

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Life-course partnership history and midlife health behaviours in a population-based birth cohort

The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement n° 324055.Background:  Marital and partnership history is strongly associated with health in midlife and later life. However, the role of health behaviours as an explanatory mechanism remains unclear. The aim of this study was to investigate prospective associations between life-course partnership trajectories (taking into account timing, non-marital cohabitation, remarriage and marital transitions) and health behaviours measured in midlife. Methods:  We analysed data from the British National Child Development Study, a prospective cohort study that includes all people born in 1 week of March 1958 (N=10 226). This study included men and women with prospective data on partnership history from age 23 to 42–44 and health behaviours collected at ages 42–46 (2000–2004). Latent class analysis was used to derive longitudinal trajectories of partnership history. We used multivariable regression models to estimate the association between midlife health behaviours and partnership trajectory, adjusting for various early and young adult characteristics. Results:  After adjustment for a range of potential selection factors in childhood and early adulthood, we found that problem drinking, heavy drinking and smoking were more common in men and women who experienced divorce or who had never married or cohabited. Women who married later had a lower prevalence of smoking and were less likely to be overweight than those who married earlier. Overall marriage was associated with a higher body mass index. Individuals who never married or cohabited spent less time exercising. Conclusions:  Some aspects of partnership history such as remaining unpartnered and experiencing divorce are associated with more smoking and drinking in midlife, whereas marriage is associated with midlife weight gain. Despite these offsetting influences, differences in health behaviours probably account for much of the association between partnership trajectories and health found in previous studies.Publisher PDFPeer reviewe

The application of quasi-elastic neutron scattering to investigate hydrogen diffusion in an iron-based Fischer-Tropsch synthesis catalyst

Sasol Ltd., (PGRS-3) the University of Glasgow and the Engineering and Physical Sciences Research Council (EP/P505534/1) are thanked for the provision of postgraduate studentship (ALD). The STFC Rutherford Appleton Laboratory is thanked for access to neutron beam facilities (RB1720188) [26]. The Royal Society are thanked for the provision of an Industrial Fellowship (PBW).Iron-based Fischer–Tropsch synthesis (FTS) catalysts evolve in situ on exposure to synthesis gas (CO & H2) forming a mixture of iron oxides, iron carbides and carbonaceous deposits. Recently, the application of inelastic neutron scattering has shown the progressive formation of a hydrocarbonaceous overlayer during this catalyst conditioning period. The evolving nature of the catalyst alters the proportion of phases present within the catalyst, which may influence the transport of hydrogen within the reaction system. Preliminary quasi-elastic neutron scattering (QENS) measurements are used to investigate hydrogen diffusion within an un-promoted iron FTS catalyst that has experienced varying levels of time-on-stream (0, 12 and 24 h) of ambient pressure CO hydrogenation at 623 K. Measurements on the catalyst samples in the absence of hydrogen show the unreacted sample (t = 0 h) to exhibit little increase in motion over the temperature range studied, whereas the t = 12 and 24 h samples exhibit a pronounced change in motion with temperature. The contrast is attributed to the presence of the afore-mentioned hydrocarbonaceous overlayer. Measurements on the samples in the presence of liquid hydrogen show hydrogen diffusional characteristics to be modified as a function of the catalyst conditioning process but, due to the complexity of the evolving catalyst matrix, the hydrogen motion cannot be attributed to a particular phase or component of the catalyst. Problems in the use of hydrogen as a probe molecule in this instance are briefly considered. Coincident neutron diffraction studies undertaken alongside the QENS measurements confirm the transition from hematite pre-catalyst to that of Hägg carbide during the course of extended times-on-stream.Publisher PDFPeer reviewe

'If it's a medical issue I would have covered it by now': learning about fibromyalgia through the hidden curriculum: a qualitative study

BACKGROUND: Fibromyalgia syndrome (FMS) is a long-term condition that affects between 1 and 5% of the general population and lies within the spectrum of medically unexplained symptoms (MUS). FMS can be difficult to diagnose and is usually done so as a diagnosis of exclusion. There is continuing debate regarding its legitimacy excluding other causes of symptoms. It is known that the diagnosis and management of MUS, including FMS, receives little attention in medical curricula and attitudes towards patients with FMS amongst medical professionals and trainees can be negative. The purpose of this study was to investigate how attitudes and perspectives of undergraduate medical students towards FMS are acquired during their training. METHODS: Qualitative interviews with 21 medical students were conducted to explore their views on FMS, encounters with patients with FMS, and where learning about FMS occurs. Participants were recruited from two English medical schools and the study was approved by two University Ethics committees. Interviews were digitally recorded with consent and data analysed thematically, using principles of constant comparison. RESULTS: The data were organised within three themes: i) FMS is a complex, poorly understood condition; ii) multiple sources for learning about FMS; and iii) consequences of negative attitudes for patients with FMS. CONCLUSION: Undergraduate medical students have limited understanding of, and are sceptical over the existence of FMS. These attitudes are influenced by the 'hidden curriculum' and witnessing attitudes and actions of their clinical teachers. Students interpret a lack of formal curriculum teaching around FMS to mean that it is not serious and hence a low priority. Encountering a patient, friend or family member with FMS can increase knowledge and lead to altered perceptions of the condition. Teaching and learning about FMS needs to be consistent to improve knowledge and attitudes of clinicians. Undergraduate students should be exposed to patients with FMS so that they better understand patients with FMS

Improving the plausibility of the missing at random assumption in the 1958 British birth cohort: A pragramatic data driven approach

Making the Missing At Random (MAR) assumption more plausible has implications for missing data analysis. We capitalise on the rich data of the National Child Development Study (NCDS - 1958 British birth cohort) and implement a systematic data-driven approach to identify predictors of non-response from the 11 sweeps (birth to age 55) of the NCDS (n = 17,415). We employed parametric regressions and the Least Absolute Shrinkage and Selection Operator for variable selection. Disadvantaged socio-economic background in childhood, worse mental health and lower cognitive ability in early life, and lack of civic and social participation in adulthood were consistently associated with non-response. Using this information, we were able to restore the composition of the NCDS samples at age 50 and age 55 to be representative of the study’s target population, using external benchmarks, and according to a number of characteristics captured within the original birth sample. We have shown that capitalising on the richness of NCDS allowed us to identify predictors of non-response that improve the plausibility of the MAR assumption. These variables can be straightforwardly used in analyses with principled methods to reduce bias due to missing data and have the strong potential to restore sample representativeness

Age of First Overweight and Obesity, COVID-19 and Long COVID in Two British Birth Cohorts

Longer exposure to obesity, and thus a longer period in an inflamed state, may increase susceptibility to infectious diseases and worsen severity. Previous cross-sectional work finds higher BMI is related to worse COVID-19 outcomes, but less is known about associations with BMI across adulthood. To examine this, we used body mass index (BMI) collected through adulthood in the 1958 National Child Development Study (NCDS) and the 1970 British Cohort Study (BCS70). Participants were grouped by the age they were first overweight (> 25 kg/m2) and obese (> 30 kg/m2). Logistic regression was used to assess associations with COVID-19 (self-reported and serology-confirmed), severity (hospital admission and contact with health services) and long-COVID reported at ages 62 (NCDS) and 50 (BCS70). An earlier age of obesity and overweight, compared to those who never became obese or overweight, was associated with increased odds of adverse COVID-19 outcomes, but results were mixed and often underpowered. Those with early exposure to obesity were over twice as likely in NCDS (odds ratio (OR) 2.15, 95% confidence interval (CI) 1.17-4.00) and three times as likely in BCS70 (OR 3.01, 95% CI 1.74-5.22) to have long COVID. In NCDS they were also over four times as likely to be admitted to hospital (OR 4.69, 95% CI 1.64-13.39). Most associations were somewhat explained by contemporaneous BMI or reported health, diabetes or hypertension; however, the association with hospital admission in NCDS remained. An earlier age of obesity onset is related to COVID-19 outcomes in later life, providing evidence of the long-term impact of raised BMI on infectious disease outcomes in midlife

Missing at random assumption made more plausible: evidence from the 1958 British birth cohort

Objective: Non-response is unavoidable in longitudinal surveys. The consequences are lower statistical power and the potential for bias. We implemented a systematic data-driven approach to identify predictors of non-response in the National Child Development Study (NCDS; 1958 British birth cohort). Such variables can help make the missing at random assumption more plausible, which has implications for the handling of missing data. / Study Design and Setting: We identified predictors of non-response using data from the 11 sweeps (birth to age 55) of the NCDS (n = 17,415), employing parametric regressions and the LASSO for variable selection. / Results: Disadvantaged socio-economic background in childhood, worse mental health and lower cognitive ability in early life, and lack of civic and social participation in adulthood were consistently associated with non-response. Using this information, along with other data from NCDS, we were able to replicate the “population distribution” of educational attainment and marital status (derived from external data), and the original distributions of key early life characteristics. / Conclusion: The identified predictors of non-response have the potential to improve the plausibility of the missing at random assumption. They can be straightforwardly used as “auxiliary variables” in analyses with principled methods to reduce bias due to missing data