An investigation of the high speed turbulent boundary layer with heat transfer and arbitrary pressure gradient. Part 1 - Summary report

Behavior of high speed turbulent boundary layer with heat transfer and streamwise pressure gradien

Observation of Mammalian Similarity Through Allometric Scaling Laws

We discuss the problem of observation of natural similarity in skeletal evolution of terrestrial mammals. Analysis is given by means of testing of the power scaling laws established in long bone allometry, which describe development of bones (of length $L$ and diameter $D$) with body mass in terms of the growth exponents, \QTR{it}{e.g.} $\lambda =d\log L/d\log D$. The bone-size evolution scenario given three decades ago by McMahon was quiet explicit on the geometrical-shape and mechanical-force constraints that predicted $\lambda =2/3$. This remains too far from the mammalian allometric exponent $\lambda ^{(\exp)}=0.80\pm 0.2$, recently revised by Christiansen, that is a chief puzzle in long bone allometry. We give therefore new insights into McMahon's constraints and report on the first observation of the critical-elastic-force, bending-deformation, muscle-induced mechanism that underlies the allometric law with estimated $\lambda =0.80\pm 0.3$. This mechanism governs the bone-size evolution with avoiding skeletal fracture caused by muscle-induced peak stresses and is expected to be unique for small and large mammals.Comment: Keywords: allometric scaling, long bones, muscles, mammals 21 pages, 1 Table, 2 Figure

Characterization of the space shuttle reaction control system engine

A computer program was developed and written in FORTRAN 5 which predicts the transient and steady state performance and heat transfer characteristics of a pulsing GO2/GH2 rocket engine. This program predicts the dynamic flow and ignition characteristics which, when combined in a quasi-steady state manner with the combustion and mixing analysis program, will provide the thrust and specific impulse of the engine as a function of time. The program also predicts the transient and steady state heat transfer characteristics of the engine using various cooling concepts. The computer program, test case, and documentation are presented. The program is applicable to any system capable of utilizing the FORTRAN 4 or FORTRAN 5 language

Finite element modeling on the effect of intra-granular porosity on the dielectric properties of BaTiO 3 MLCCs

The effect of porosity on the electrical properties of BaTiO3-based MultilayerCeramic Capacitors (MLCCs) is studied. A dense ceramic prepared via powderfrom a solid-state processing route is compared against a ceramic that containsintra-granular pores from powder prepared via hydrothermal processing. Finiteelement models are created to contain intra-granular pores, solved and analyzed toshow an increase in the electric field and current density surrounding the pores.For single-pore and two intra-pore arrangements, the electric field is enhanced bya factor of~1.5 and 2.5, respectively, when compared to a fully dense (pore-free)material. For ceramics with equivalent density, the number of pores dramaticallyalters the electrical response. For a system containing 100 pores, the electric fieldcan increase at least fourfold, therefore facilitating a possible starting route forelectrical breakdown of the grain. These results are compared to the Gerson-Mar-shall model, typically used in the literature for the calculation of the breakdownstrength due to porosity. The results highlight the need to include the effect ofadjacent pore interactions. Although studied here for BaTiO3-based MLCC’s theresults are applicable to other devices based on ceramics containing porosity

Moving from evidence-based medicine to evidence-based health.

While evidence-based medicine (EBM) has advanced medical practice, the health care system has been inconsistent in translating EBM into improvements in health. Disparities in health and health care play out through patients' limited ability to incorporate the advances of EBM into their daily lives. Assisting patients to self-manage their chronic conditions and paying attention to unhealthy community factors could be added to EBM to create a broader paradigm of evidence-based health. A perspective of evidence-based health may encourage physicians to consider their role in upstream efforts to combat socially patterned chronic disease

Social network analysis of stakeholder networks from two community-based obesity prevention interventions

IntroductionStudies of community-based obesity prevention interventions have hypothesized that stakeholder networks are a critical element of effective implementation. This paper presents a quantitative analysis of the interpersonal network structures within a sub-sample of stakeholders from two past successful childhood obesity prevention interventions.MethodsParticipants were recruited from the stakeholder groups (steering committees) of two completed community-based intervention studies, Romp &amp; Chomp (R&amp;C), Australia (2004-2008) and Shape Up Somerville (SUS), USA (2003-2005). Both studies demonstrated significant reductions of overweight and obesity among children. Members of the steering committees were asked to complete a retrospective social network questionnaire using a roster of other committee members and free recall. Each participant was asked to recall the people with whom they discussed issues related to childhood obesity throughout the intervention period, along with providing the closeness and level of influence of each relationship.ResultsNetworks were reported by 13 participants from the SUS steering committee and 8 participants from the R&amp;C steering committee. On average, participants nominated 16 contacts with whom they discussed issues related to childhood obesity through the intervention, with approximately half of the relationships described as &lsquo;close&rsquo; and 30% as &lsquo;influential&rsquo;. The &lsquo;discussion&rsquo; and &lsquo;close&rsquo; networks had high clustering and reciprocity, with ties directed to other steering committee members, and to individuals external to the committee. In contrast, influential ties were more prominently directed internal to the steering committee, with higher network centralization, lower reciprocity and lower clustering.Discussion and conclusionSocial network analysis provides a method to evaluate the ties within steering committees of community-based obesity prevention interventions. In this study, the network characteristics between a sub-set of stakeholders appeared to be supportive of diffused communication. Future work should prospectively examine stakeholder network structures in a heterogeneous sample of community-based interventions to identify elements most strongly associated with intervention effectiveness.<br /

Healthy-lifestyle behaviors associated with overweight and obesity in US rural children

BackgroundThere are disproportionately higher rates of overweight and obesity in poor rural communities but studies exploring children&rsquo;s health-related behaviors that may assist in designing effective interventions are limited. We examined the association between overweight and obesity prevalence of 401 ethnically/racially diverse, rural school-aged children and healthy-lifestyle behaviors: improving diet quality, obtaining adequate sleep, limiting screen-time viewing, and consulting a physician about a child&rsquo;s weight.MethodsA cross-sectional analysis was conducted on a sample of school-aged children (6&ndash;11 years) in rural regions of California, Kentucky, Mississippi, and South Carolina participating in CHANGE (Creating Healthy, Active, and Nurturing Growing-up Environments) Program, created by Save the Children, an independent organization that works with communities to improve overall child health, with the objective to reduce unhealthy weight gain in these school-aged children (grades 1&ndash;6) in rural America. After measuring children&rsquo;s height and weight, we17 assessed overweight and obesity (BMI &ge; 85th percentile) associations with these behaviors: improving diet quality18 (&ge; 2 servings of fruits and vegetables/day), reducing whole milk, sweetened beverage consumption/day; obtaining19 adequate night-time sleep on weekdays (&ge; 10 hours/night); limiting screen-time (i.e., television, video, computer,20 videogame) viewing on weekdays (&le; 2 hours/day); and consulting a physician about weight. Analyses were adjusted 21 for state of residence, children\u27s race/ethnicity, gender, age, and government assistance.ResultsOverweight or obesity prevalence was 37 percent in Mississippi and nearly 60 percent in Kentucky. Adjusting for covariates, obese children were twice as likely to eat &ge; 2 servings of vegetables per day (OR=2.0,95% CI 1.1-3.4), less likely to consume whole milk (OR=0.4,95% CI 0.2-0.70), Their parents are more likely to be told by their doctor that their child was obese (OR=108.0,95% CI 21.9-541.6), and less likely to report talking to their child about fruits and vegetables a lot/sometimes vs. not very much/never (OR=0.4, 95%CI 0.2-0.98) compared to the parents of healthy-weight children.ConclusionsRural children are not meeting recommendations to improve diet, reduce screen time and obtain adequate sleep. Although we expected obese children to be more likely to engage in unhealthy behaviors, we found the opposite to be true. It is possible that these groups of respondent parents were highly aware of their weight status and have been advised to change their children&rsquo;s health behaviors. Perhaps given the opportunity to participate in an intervention study in combination with a physician recommendation could have resulted in actual behavior change

Healthier side dishes at restaurants: an analysis of children’s perspectives, menu content, and energy impacts

BACKGROUND: Children consume restaurant-prepared foods at high rates, suggesting that interventions and policies targeting consumption of these foods have the potential to improve diet quality and attenuate excess energy intake. One approach to encouraging healthier dietary intake in restaurants is to offer fruits and vegetables (FV) as side dishes, as opposed to traditional, energy-dense accompaniments like French fries. The aims of the current study were to examine: children's views about healthier side dishes at restaurants; current side dish offerings on children's menus at leading restaurants; and potential energy reductions when substituting FV side dishes in place of French fries. METHODS: To investigate children’s attitudes, a survey was administered to a nationally representative sample of U.S. 8- to 18-year-olds (n = 1178). To examine current side dish offerings, children's menus from leading quick service (QSR; n = 10) and full service restaurant chains (FSR; n = 10) were analyzed. Energy reductions that could result from substituting commonly-offered FV side dishes for French fries were estimated using nutrition information corresponding to the children's menu items. RESULTS: Two-thirds of children reported that they would not feel negatively about receiving FV sides instead of French fries with kids' meals. Liking/taste was the most common reason that children gave to explain their attitudes about FV side dishes. Nearly all restaurants offered at least 1 FV side dish option, but at most restaurants (60% of QSR; 70% of FSR), FV sides were never served by default. Substituting FV side dishes for French fries yielded an average estimated energy reduction of at least 170 calories. CONCLUSIONS: Results highlight some healthy trends in the restaurant context, including the majority of children reporting non-negative attitudes about FV side dishes and the consistent availability of FV side dish options at leading QSR and FSR. Yet the minority of restaurants offer these FV sides by default. Promoting creative, appealing FV side dishes can result in healthier, less energy-dense meals for children. Substituting or displacing energy-dense default side dishes with such FV dishes show promise as part of continued, comprehensive efforts to increase the healthfulness of meals consumed by children in restaurant settings

Peptide Nucleic Acids and CRISPR-Cas9: Mechanisms and Rational Applications for Gene Editing Systems

In the past decade, gene editing technology development has exploded across life sciences fields with promise to advance research, agriculture, industry, and the development of curative human therapeutics. Initially lead by CRISPR-associated nucleases and their ability to induce targeted DNA double-strand breaks (DSBs), the gene editing toolbox continues to grow as new technologies emerge and improve. While the goal of these tools is to precisely manipulate DNA sequences in living cells, not all modifications are created equal. Small or large deletions and insertions, precise nucleotide changes, and combination approaches each entail different challenges and require cooperation with endogenous repair pathways to achieve an intended effect. No one tool can accomplish these biochemical feats in a one-fits-all manner. Thus, it is imperative to advance current technologies and create new approaches as diverse as the problems they set out to solve while maximizing safety for potential use in human therapy. The overarching goal of this dissertation is to apply principles of DNA repair and nucleic acid biochemistry to advance our understanding and implementation of gene editing tools across applications. First, using a novel high-throughput platform to detect nucleic acid structure interactomes, we reveal that synthetic triplex-forming peptide nucleic acids (PNAs) bind DNA strands to elicit repair factors and pathways previously unknown to participate in site-directed gene editing. Specifically, by interrogating and comparing up to 2688 parallel nucleic acid-protein interactions in vitro, we identified PNA triplex-bound factors implicated in nucleotide excision repair (XPA, XPC), single-strand annealing repair (RAD52), and recombination intermediate structure binding (TOP3A, BLM, MUS81). We go on to suggest measures for improving PNA-mediated gene editing efficiencies and potential strategies for safe novel gene editing approaches. In this work, we also outline the development, characterization, and application of PNAs to modulate CRISPR-Cas9 activity and affinity for target genomic sequences. Based on rational antisense targeting of PNAs to guide RNA (gRNA) sequences, we describe methods to rapidly inhibit Cas9 for facile spatiotemporal control or to improve overall specificity and reduce deleterious off-target editing. This is a seminal study for the use of PNAs to modulate enzymatic activity and engineer nucleoproteins by direct antisense binding, and demonstrably improves gene editing safety and versatility without associated cellular toxicity. Finally, to understand the influence of novel metabolites on DNA repair deficiency in IDH mutant cancers, we use a computationally informed CRISPR-Cas9 design pipeline to correlate local methylation status with DSB repair at endogenous loci throughout the genome. Building on a body of prior work, we use this approach to establish the mechanism by which oncometabolites induce hypermethylation of histone 3 lysine 9 (H3K9) to mask local chromatin signaling required for proper DSB repair. This finding indicates potential strategies for targeted therapeutics in this prevalent class of cancers. Overall, this work establishes multiple advances for the improvement of gene editing tools and our ability to rationally manipulate DNA sequences in living cells. As part of a larger and continually evolving body of work, these projects progress our ability to develop and apply innovative, versatile, and safe next-generation gene editors for future human therapeutics and beyond