Vibration Isolation Design for the Micro-X Rocket Payload

Micro-X is a NASA-funded, sounding rocket-borne X-ray imaging spectrometer that will allow high precision measurements of velocity structure, ionization state and elemental composition of extended astrophysical systems. One of the biggest challenges in payload design is to maintain the temperature of the detectors during launch. There are several vibration damping stages to prevent energy transmission from the rocket skin to the detector stage, which causes heating during launch. Each stage should be more rigid than the outer stages to achieve vibrational isolation. We describe a major design effort to tune the resonance frequencies of these vibration isolation stages to reduce heating problems prior to the projected launch in the summer of 2014.Comment: 6 pages, 7 figures, LTD15 Conference Proceeding

What Matters for Boys Does Not Necessarily Matter for Girls : Gender-Specific Relations between Perceived Self-Determination, Engagement, and Performance in School Mathematics

While math performance does not seem to differ systematically between males and females, it is one of the subjects that is consistently perceived as “male” with girls regularly reporting lower levels of motivation and less positive attitudes than boys. This study aimed to uncover genderspecific relations between perceived self-determination, engagement, and performance in school mathematics that might help to better understand this discrepancy. In an online study, we hence assessed perceived competence and autonomy support, social relatedness, cognitive and behavioral engagement, math performance as well as sustained attention as a basic cognitive prerequisite in a sample of N = 221 Seventh-Grade students from southern Germany (Mage = 12.84 years, SDage = 0.55, Nfemales = 115). As expected, we found no gender differences in math performance. In multiple group path analyses, perceived autonomy support was the most consistent predictor of cognitive and behavioral engagement for both girls and boys. While it did not affect math performance directly, we found significant indirect effects via cognitive engagement for girls, and via behavioral engagement for boys, whereas competence support in the math classroom, which female students perceived as significantly lower than male students, negatively predicted only girls’ performance, sustained attention explained a considerable part of boys’ math performance. Girls seem to experience competence support less often than boys, and if they do, we assume it to be in response to low performance rather than to encourage high competence and nurture talent. Our results suggest promising avenues for future research and implications for math classrooms

Magnetocaloric Materials and the Optimization of Cooling Power Density

The magnetocaloric effect is the thermal response of a material to an external magnetic field. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. After a brief overview of the magnetocaloric effect and associated thermodynamics, typical requirements on refrigerants are discussed from a standpoint of cooling power density optimization. Finally, a compilation of the most important properties of several common magnetocaloric materials is presented

A DECADE-BASELINE STUDY OF THE PLASMA STATES OF EJECTA KNOTS IN CASSIOPEIA A

We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and thermal state of the plasma in each knot, using a combined analysis of two high energy resolution High Energy Transmission Grating (HETG) and four medium energy resolution Advanced CCD Imaging Spectrometer (ACIS) sets of spectra. The ACIS electron temperature estimates agree with the HETG-derived values for approximately half of the knots studied, yielding one of the first comparisons between high resolution temperature estimates and ACIS-derived temperatures. We did not observe the expected spectral evolution—predicted from the ionization age and density estimates for each knot—in all but three of the knots studied. The incompatibility of these measurements with our assumptions has led us to propose a dissociated ejecta model, with the metals unmixed inside the knots, which could place strong constraints on supernova mixing models.United States. National Aeronautics and Space Administration (Award NNX10AE25G)National Science Foundation (U.S.) (Partnerships in Astronomy & Astrophysics Research and Education Grant AST-0849736)United States. National Aeronautics and Space Administration (Earth and Space Science Fellowship)United States. National Aeronautics and Space Administration (Harriet Jenkins Predoctoral Fellowship Program)Vanderbilt University (Provost Graduate Fellowship

Frailty phenotype and its association with all-cause mortality in community-dwelling Norwegian women and men aged 70 years and older: The Tromsø Study 2001-2016.

AIM: There is a lack of studies on the prevalence of frailty, and the association between frailty and mortality in a Norwegian general population. Findings regarding sex differences in the association between frailty and mortality have been inconsistent. The aim of the present study was to investigate the association between the frailty phenotype and all-cause mortality in men and women in a Norwegian cohort study. METHODS: We followed 712 participants (52% women) aged ≥70 years participating in the population-based Tromsø 5 Study in 2001-2002 for all-cause mortality up to 2016. The frailty status at baseline was defined by a modified version of Fried's frailty criteria. Cox regression models were used to analyze the association between frailty and mortality with adjustment for age, sex, disability, comorbidity, smoking status and years of education. RESULTS: In total, 3.8% (n = 27) of participants were frail (women 4.4%, men 3.2%) and 38.1% (n = 271) were pre-frail (women 45.8%, men 29.9%). During follow-up (mean 10.1 years), 501 (70%) participants died. We found an increased risk of mortality for frail older adults (multivariable-adjusted HR 4.16, 95% CI 2.40-7.22) compared with non-frail older adults. In sex-stratified analysis, the adjusted HR was 7.09 (95% CI 3.03-16.58) for frail men and 2.93 (95% CI 1.38-6.22) for frail women. Results for pre-frailty showed an overall weaker association with mortality. CONCLUSIONS: While frailty was more prevalent in women than in men, the findings suggest that the association between frailty and mortality is stronger in men than in women. Geriatr Gerontol Int 2018; 18: 1200-1205

A meta-analysis of protein binding of flucloxacillin in healthy volunteers and hospitalized patients

Objectives: The aim of this study was to develop a mechanistic protein-binding model to predict the unbound flucloxacillin concentrations in different patient populations. Methods: A mechanistic protein-binding model was fitted to the data using non-linear mixed-effects modelling. Data were obtained from four datasets, containing 710 paired total and unbound flucloxacillin concentrations from healthy volunteers, non-critically ill and critically ill patients. A fifth dataset with data from hospitalized patients was used for evaluation of our model. The predictive performance of the mechanistic model was evaluated and compared with the calculation of the unbound concentration with a fixed unbound fraction of 5%. Finally, we performed a fit-for-use evaluation, verifying whether the model-predicted unbound flucloxacillin concentrations would lead to clinically incorrect dose adjustments. Results: The mechanistic protein-binding model predicted the unbound flucloxacillin concentrations more accurately than assuming an unbound fraction of 5%. The mean prediction error varied between -26.2% to 27.8% for the mechanistic model and between -30.8% to 83% for calculation with a fixed factor of 5%. The normalized root mean squared error varied between 36.8% and 69% respectively between 57.1% and 134%. Predicting the unbound concentration with the use of the mechanistic model resulted in 6.1% incorrect dose adjustments versus 19.4% if calculated with a fixed unbound fraction of 5%. Conclusions: Estimating the unbound concentration with a mechanistic protein-binding model outperforms the calculation with the use of a fixed protein binding factor of 5%, but neither demonstrates acceptable performance. When performing dose individualization of flucloxacillin, this should be done based on measured unbound concentrations rather than on estimated unbound concentrations from the measured total concentrations. In the absence of an assay for unbound concentrations, the mechanistic binding model should be preferred over assuming a fixed unbound fraction of 5%

Development and implementation of the physiotherapy-led exercise interventions for the treatment of rotator cuff disorders for the ‘Getting it Right:Addressing Shoulder Pain’ (GRASP) trial

The Getting it Right: Addressing Shoulder Pain (GRASP) trial is a large-scale, multicentre, randomised controlled trial investigating the clinical and cost-effectiveness of a progressive exercise intervention versus a best-practice advice intervention, with or without corticosteroid injection, for treating people with a rotator cuff disorder. Interventions were developed using the Medical Research Council guidance on complex interventions, and included a stakeholder meeting of 26 clinicians, researchers, and patient representatives. The best-practice advice (1 session) and progressive exercise (≤6 sessions over 16 weeks) interventions both involve face-to-face, one-to-one physiotherapist appointments and include self-management advice, home-exercise instruction, and behaviour-change strategies to target exercise adherence. The results of the GRASP trial are anticipated in 2020. This large scale evaluation on 704 participants will provide high quality evidence to best inform clinical practice for the management of people with shoulder pain due to a rotator cuff disorder. A critical stage of evaluating the complex interventions in the GRASP trial is ensuring details of the development and content of the interventions are available to clinicians and researchers to facilitate their implementation