Lessons learned in creating spacecraft computer systems: Implications for using Ada (R) for the space station

Twenty-five years of spacecraft onboard computer development have resulted in a better understanding of the requirements for effective, efficient, and fault tolerant flight computer systems. Lessons from eight flight programs (Gemini, Apollo, Skylab, Shuttle, Mariner, Voyager, and Galileo) and three reserach programs (digital fly-by-wire, STAR, and the Unified Data System) are useful in projecting the computer hardware configuration of the Space Station and the ways in which the Ada programming language will enhance the development of the necessary software. The evolution of hardware technology, fault protection methods, and software architectures used in space flight in order to provide insight into the pending development of such items for the Space Station are reviewed

Diet and lifestyle interventions to improve co-morbid conditions of chronic kidney disease

Chronic kidney disease is a progressive inflammatory disorder affecting approximately 15% of US adults, and the prevalence is increasing rapidly. Advanced chronic kidney disease requiring hemodialysis is associated with multiple co-morbid conditions that greatly reduce physical function and quality of life, including muscle wasting, bone disorders, and cardiovascular disease. Protein-energy malnutrition is especially common for reasons including poor nutrient intake, amino acid losses during dialysis, and elevated intradialytic catabolism; these factors promote loss of lean mass and declines in physical function. Low physical function and adverse changes in body composition accelerate development of other co-morbid conditions, highlighting the cycle of disease and disability characteristic of this population. Numerous pharmacological therapies are commonly used in an effort to reduce the incidence or severity of chronic kidney disease co-morbidities, but these treatments are associated with high costs and significant side effects. Furthermore, the complexity of chronic kidney disease suggests multiple therapeutic approaches may be beneficial in this population. Intradialytic protein supplementation and exercise training during dialysis are two lifestyle interventions that have been suggested as potential methods to mitigate the cycle of disease and disability. Studies have shown that both parenteral and oral intradialytic supplementation improve protein homeostasis, increase serum albumin and prealbumin levels, and have anabolic effects on skeletal muscle. However, the effect of intradialytic protein on functional disease outcomes in this population is not known. Similarly, numerous studies have demonstrated that intradialytic exercise training has beneficial effects on physical function and quality of life, but surprisingly few studies have examined its effect on other clinical outcomes, particularly cardiovascular disease. The goal of this research was to examine the relationships between the comorbid conditions associated with advanced chronic kidney disease, and determine the efficacy of intradialytic protein supplementation and exercise training as therapeutic approaches. This goal was accomplished through a series of studies both in animal models and also in clinical populations. In a mouse model of renal insufficiency, a combination of soy protein and exercising improved bone microarchitecture and a main effect of soy protein consumption was observed for improvements plasma urea as an indicator of renal function; results from this study an others prompted consideration of these effects in a clinical population. In a cross-sectional analysis of sixty hemodialysis patients, we found multiple aspects of chronic kidney disease to be interrelated, supporting the idea of the cycle of disease and disability characteristic of these patients. This study was notable for its comprehensive inclusion of functional outcome variables associated with hemodialysis treatment in an effort to characterize relationships among these factors, and possibly provide information on how best to intervene to improve health outcomes in this extremely sick population. For the first clinical intervention study, seventeen hemodialysis patients completed a four month intradialytic cycling program; exercising during dialysis improved physical functioning and improved cardiovascular disease risk as measured by serum alkaline phosphatase and epicardial fat thickness. Protein intake during dialysis, either soy or whey protein, attenuated inflammation associated with a single dialysis session and reduced the acute phase protein response after a six month supplementation program. Long-term protein intake also improved physical functioning and reduced circulating alkaline phosphatase levels, similar to the findings after four months of intradialytic cycling. Taken together, these data suggest modest benefits of intradialytic exercise and protein supplementation on functional outcomes in this critically ill population. Future directions include investigating the combined effects of intradialytic protein and exercise in maintenance dialysis patients, as the complexity of the disease suggests multiple therapeutic strategies may be necessary to improve health outcomes and quality of life for this population

An examination of the working conditions, challenges, and tensions experienced by mathematics teachers

To make the professional work of teachers more effective and personally satisfying, it is important to better understand the nature and effects of the evident stresses in their work. The purpose of this study was to describe the quality of work life of mathematics teachers in Maryland, with an eye on ultimately helping the mathematics teaching profession and the broader education community to improve both the effectiveness and satisfaction of K-12 teachers of mathematics. Since school systems share many features with large organizations, the design of the present study utilized prior research from industry on stress in the workplace to help in understanding the strains of mathematics teaching. A review of literature suggested five potential stressors which formed the basis of the study. The five stressors were: the congruence of individual and organizational goals, teachers' sense of agency, teachers' sense of efficacy and respect, the level of professional interactions between teachers, and the appropriateness of teachers' work load. From these stressors, Likert-type survey statements were generated and organized into a 77-item, online survey instrument. Participants were solicited through flyers and e-mails. The survey data was analyzed in two ways. First, teacher working conditions were evaluated in terms of the five potential stressors. Then, a factor analysis of the survey data identified six underlying components of stress in the work lives of mathematics teachers. Teacher working conditions were then re-evaluated with respect to these six components. Finally, a few of the survey participants were selected for follow-up interviews to provide additional insights into their responses. Statistical analysis using ANOVA and multiple comparison procedures resulted in several findings. Mathematics teachers expressed having a lack of agency, particularly with respect to decisions impacting instruction and assessment. Participants reported feeling overloaded by their job responsibilities and many even cited interruptions to both planning time and instructional time as serious obstacles to teaching. On the other hand, mathematics teachers felt a strong sense of accomplishment. Comments provided by participants indicate that they thrive on seeing students learn, grow, and succeed in mathematics

Image-based dietary assessment ability of dietetics students and interns

Image-based dietary assessment (IBDA) may improve the accuracy of dietary assessments, but no formalized training currently exists for skills relating to IBDA. This study investigated nutrition and dietetics students’ and interns’ IBDA abilities, the training and experience factors that may contribute to food identification and quantification accuracy, and the perceived challenges to performing IBDA. An online survey containing images of known foods and serving sizes representing common American foods was used to assess the ability to identify foods and serving sizes. Nutrition and dietetics students and interns from the United States and Australia (n = 114) accurately identified foods 79.5% of the time. Quantification accuracy was lower, with only 38% of estimates within ±10% of the actual weight. Foods of amorphous shape or higher energy density had the highest percent error. Students expressed general difficulty with perceiving serving sizes, making IBDA food quantification more difficult. Experience cooking at home from a recipe, frequent measuring of portions, and having a food preparation or cooking laboratory class were associated with enhanced accuracy in IBDA. Future training of dietetics students should incorporate more food-based serving size training to improve quantification accuracy while performing IBDA, while advances in IBDA technology are also needed. © 2017 by the authors; licensee MDPI, Basel, Switzerland

New markers for murine memory B cells that define mutated and unmutated subsets

The study of murine memory B cells has been limited by small cell numbers and the lack of a definitive marker. We have addressed some of these difficulties with hapten-specific transgenic (Tg) mouse models that yield relatively large numbers of antigen-specific memory B cells upon immunization. Using these models, along with a 5-bromo-2′-deoxyuridine (BrdU) pulse-label strategy, we compared memory cells to their naive precursors in a comprehensive flow cytometric survey, thus revealing several new murine memory B cell markers. Most interestingly, memory cells were phenotypically heterogeneous. Particularly surprising was the finding of an unmutated memory B cell subset identified by the expression of CD80 and CD35. We confirmed these findings in an analogous V region knock-in mouse and/or in non-Tg mice. There also was anatomic heterogeneity, with BrdU+ memory cells residing not just in the marginal zone, as had been thought, but also in splenic follicles. These studies impact the current understanding of murine memory B cells by identifying new phenotypes and by challenging assumptions about the location and V region mutation status of memory cells. The apparent heterogeneity in the memory compartment implies either different origins and/or different functions, which we discuss

Parent Involvement in Diet or Physical Activity Interventions to Treat or Prevent Childhood Obesity: An Umbrella Review

Parents substantially influence children’s diet and physical activity behaviors, which consequently impact childhood obesity risk. Given this influence of parents, the objective of this umbrella review was to synthesize evidence on effects of parent involvement in diet and physical activity treatment and prevention interventions on obesity risk among children aged 3–12 years old. Ovid/MEDLINE, Elsevier/Embase, Wiley/Cochrane Library, Clarivate/Web of Science, EBSCO/CINAHL, EBSCO/PsycInfo, and Epistemonikos.org were searched from their inception through January 2020. Abstract screening, full-text review, quality assessment, and data extraction were conducted independently by at least two authors. Systematic reviews and meta-analyses of diet and physical activity interventions that described parent involvement, included a comparator/control, and measured child weight/weight status as a primary outcome among children aged 3–12 years old were included. Data were extracted at the level of the systematic review/meta-analysis, and findings were narratively synthesized. Of 4158 references identified, 14 systematic reviews and/or meta-analyses (eight treatment focused and six prevention focused) were included and ranged in quality from very low to very high. Our findings support the inclusion of a parent component in both treatment and prevention interventions to improve child weight/weight status outcomes. Of note, all prevention-focused reviews included a school-based component. Evidence to define optimal parent involvement type and duration and to define the best methods of involving parents across multiple environments (e.g., home, preschool, school) was inadequate and warrants further research

Tumor volume in subcutaneous mouse xenografts measured by microCT is more accurate and reproducible than determined by 18F-FDG-microPET or external caliper

<p>Abstract</p> <p>Background</p> <p>In animal studies tumor size is used to assess responses to anticancer therapy. Current standard for volumetric measurement of xenografted tumors is by external caliper, a method often affected by error. The aim of the present study was to evaluate if microCT gives more accurate and reproducible measures of tumor size in mice compared with caliper measurements. Furthermore, we evaluated the accuracy of tumor volume determined from ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET.</p> <p>Methods</p> <p>Subcutaneously implanted human breast adenocarcinoma cells in NMRI nude mice served as tumor model. Tumor volume (n = 20) was determined <it>in vivo </it>by external caliper, microCT and ¹⁸F-FDG-PET and subsequently reference volume was determined <it>ex vivo</it>. Intra-observer reproducibility of the microCT and caliper methods were determined by acquiring 10 repeated volume measurements. Volumes of a group of tumors (n = 10) were determined independently by two observers to assess inter-observer variation.</p> <p>Results</p> <p>Tumor volume measured by microCT, PET and caliper all correlated with reference volume. No significant bias of microCT measurements compared with the reference was found, whereas both PET and caliper had systematic bias compared to reference volume. Coefficients of variation for intra-observer variation were 7% and 14% for microCT and caliper measurements, respectively. Regression coefficients between observers were 0.97 for microCT and 0.91 for caliper measurements.</p> <p>Conclusion</p> <p>MicroCT was more accurate than both caliper and ¹⁸F-FDG-PET for <it>in vivo </it>volumetric measurements of subcutaneous tumors in mice.¹⁸F-FDG-PET was considered unsuitable for determination of tumor size. External caliper were inaccurate and encumbered with a significant and size dependent bias. MicroCT was also the most reproducible of the methods.</p

Vancomycin-resistant enterococci from nosocomial, community, and animal sources in the United States.

The presence of vancomycin-resistant enterococci (VRE) was looked for in fecal samples from 104 healthy volunteers (3 with hospital exposure), 100 selected hospitalized patients, and various environmental sources (44 commercial chickens, 5 farm-raised chickens, 3 turkeys, and 2 chicken farm lagoon slurries). Five probiotic preparations were also studied. No VRE with vanA or vanB genes were isolated from the healthy volunteers without hospital exposure, environmental sources, or probiotic preparations. VRE with vanB were found in the stools of 16% of the high-risk hospitalized patients and in one volunteer with hospital contact. All VRE examined could be classified into one of two clones by pulsed-field gel electrophoresis. VRE from 11 of the colonized patients were quantified and ranged from 10(3) to 10(6) CFU/g of stool. This study, in contrast to findings in Europe, failed to find evidence of VanA- or VanB-type VRE in the community or environmental sources in Houston, Texas, and suggests that these settings are not a likely source of VRE in hospitals in this geographic area