Trade Studies for a Manned High-Power Nuclear Electric Propulsion Vehicle

Nuclear electric propulsion (NEP) vehicles will be needed for future manned missions to Mars and beyond. Candidate vehicles must be identified through trade studies for further detailed design from a large array of possibilities. Genetic algorithms have proven their utility in conceptual design studies by effectively searching a large design space to pinpoint unique optimal designs. This research combines analysis codes for NEP subsystems with genetic algorithm-based optimization. Trade studies for a NEP reference mission to the asteroids were conducted to identify important trends, and to determine the effects of various technologies and subsystems on vehicle performance. It was found that the electric thruster type and thruster performance have a major impact on the achievable system performance, and that significant effort in thruster research and development is merited

“Economic man” in cross-cultural perspective: Behavioral experiments in 15 small-scale societies

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model – based on self-interest – fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life

Galaxy growth by merging in the nearby universe

We measure the mass growth rate by merging for a wide range of galaxy types. We present the small-scale (0.014 < r < 11 h70^{-1} Mpc) projected cross-correlation functions w(rp) of galaxy subsamples from the spectroscopic sample of the NYU VAGC (5 \times 10^5 galaxies of redshifts 0.03 < z < 0.15) with galaxy subsamples from the SDSS imaging (4 \times 10^7 galaxies). We use smooth fits to de-project the two-dimensional functions w(rp) to obtain smooth three-dimensional real-space cross-correlation functions \xi(r) for each of several spectroscopic subsamples with each of several imaging subsamples. Because close pairs are expected to merge, the three-space functions and dynamical evolution time estimates provide galaxy accretion rates. We find that the accretion onto massive blue galaxies and onto red galaxies is dominated by red companions, and that onto small-mass blue galaxies, red and blue galaxies make comparable contributions. We integrate over all types of companions and find that at fixed stellar mass, the total fractional accretion rates onto red galaxies (\sim 1.5 h70 percent per Gyr) is greater than that onto blue galaxies (\sim 0.5 h70 percent per Gyr). Although these rates are very low, they are almost certainly over-estimates because we have assumed that all close pairs merge as quickly as dynamical friction permits.Comment: submitted to APJ on 08/20/201

Evaluation of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA

Citation: Dryden, M. W., Smith, V., Chwala, M., Jones, E., Crevoiserat, L., McGrady, J. C., . . . Carithers, D. (2015). Evaluation of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA. Parasites & Vectors, 8, 7. doi:10.1186/s13071-015-0897-zBackground: A study was conducted to evaluate the effectiveness of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA. Evaluations of on-animal and premises flea burdens, flea sex structure and fed-unfed premises flea populations were conducted to more accurately assess flea population dynamics in households. Methods: Thirty seven naturally flea infested dogs in 23 homes in Tampa, FL were enrolled in the study and treated with afoxolaner chewables. Chewables (NexGard (R) Chewables; Merial) were administered according to label directions by study investigators on study day 0 and once again between study days 28 and 30. Flea infestations on pets were assessed using visual area thumb counts and premises flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, and once between study days 28-30, 40-45, and 54-60. Results: Within 7 days of administration of afoxolaner chewable tablets, flea counts on dogs were reduced by 99.3 %. By one month post-treatment, total flea counts on dogs were reduced by 99.9 %, with 97.3 % (36/37) of the dogs being flea free. Following the second dosing on study day 28-30, total on-dog flea burden was reduced by 100 % on days 40-45 and 54-60. On day 0, the traps collected a geometric mean of 18.2 fleas. Subsequent reductions in emerging flea populations were 97.7 and 100 % by days 28-30 and 54-60, respectively. There were 515 total fleas (Ctenocephalides felis felis) collected in the intermittent light flea traps on day 0, and 40.4 % of those fleas displayed visual evidence of having fed. Seven days after initial treatment, only 13.1 % of the fleas contained blood and by day 14 only 4.9 % of the fleas collected in traps displayed evidence of having fed. On day 0, prior to treatment, 60 % of the unfed fleas collected in intermittent-light flea traps were females, but by days 28-30, unfed males accounted for 78 % of the population. Conclusions: This in-home investigation conducted during the summer of 2014 in subtropical Tampa, FL demonstrated that afoxolaner chewables rapidly and effectively eliminated flea populations in infested dogs and homes

External Bone Size Is a Key Determinant of Strength‐Decline Trajectories of Aging Male Radii

Given prior work showing associations between remodeling and external bone size, we tested the hypothesis that wide bones would show a greater negative correlation between whole‐bone strength and age compared with narrow bones. Cadaveric male radii (n = 37 pairs, 18 to 89 years old) were evaluated biomechanically, and samples were sorted into narrow and wide subgroups using height‐adjusted robustness (total area/bone length). Strength was 54% greater (p < 0.0001) in wide compared with narrow radii for young adults (<40 years old). However, the greater strength of young‐adult wide radii was not observed for older wide radii, as the wide (R2 = 0.565, p = 0.001), but not narrow (R2 = 0.0004, p = 0.944) subgroup showed a significant negative correlation between strength and age. Significant positive correlations between age and robustness (R2 = 0.269, p = 0.048), cortical area (Ct.Ar; R2 = 0.356, p = 0.019), and the mineral/matrix ratio (MMR; R2 = 0.293, p = 0.037) were observed for narrow, but not wide radii (robustness: R2 = 0.015, p = 0.217; Ct.Ar: R2 = 0.095, p = 0.245; MMR: R2 = 0.086, p = 0.271). Porosity increased with age for the narrow (R2 = 0.556, p = 0.001) and wide (R2 = 0.321, p = 0.022) subgroups. The wide subgroup (p < 0.0001) showed a significantly greater elevation of a new measure called the Cortical Pore Score, which quantifies the cumulative effect of pore size and location, indicating that porosity had a more deleterious effect on strength for wide compared with narrow radii. Thus, the divergent strength–age regressions implied that narrow radii maintained a low strength with aging by increasing external size and mineral content to mechanically offset increases in porosity. In contrast, the significant negative strength–age correlation for wide radii implied that the deleterious effect of greater porosity further from the centroid was not offset by changes in outer bone size or mineral content. Thus, the low strength of elderly male radii arose through different biomechanical mechanisms. Consideration of different strength–age regressions (trajectories) may inform clinical decisions on how best to treat individuals to reduce fracture risk. © 2019 American Society for Bone and Mineral Research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149566/1/jbmr3661_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149566/2/jbmr3661.pd

The Grizzly, September 28, 1999

Cheer on UC at Family Day! • Taking to the Ballots • Change in Ursinus Security: Good or Bad? • Family Day Has Arrived • Living Off Campus Just Like Home • Campus Unable to Check Messages on Voice Mail • Bon Appetite at Back Porch Cafe • Letter to the Editor: Censorship in the Grizzly • Editors\u27 Response to Censorship Allegations • Volleyball Continues its Winning Ways • A Weekend of Success in U.C. Field Hockey • Bears Football Suffers 1st Loss of Season to #1 W. Marylandhttps://digitalcommons.ursinus.edu/grizzlynews/1446/thumbnail.jp

Learning health ‘safety’ within non-technical skills interprofessional simulation education: a qualitative study

Background: Healthcare increasingly recognises and focusses on the phenomena of ‘safe practice’ and ‘patient safety.’ Success with non-technical skills (NTS) training in other industries has led to widespread transposition to healthcare education, with communication and teamwork skills central to NTS frameworks. Objective: This study set out to identify how the context of interprofessional simulation learning influences NTS acquisition and development of ‘safety’ amongst learners. Methods: Participants receiving a non-technical skills (NTS) safety focussed training package were invited to take part in a focus group interview which set out to explore communication, teamwork, and the phenomenon of safety in the context of the learning experiences they had within the training programme. The analysis was aligned with a constructivist paradigm and took an interactive methodological approach. The analysis proceeded through three stages, consisting of open, axial, and selective coding, with constant comparisons taking place throughout each phase. Each stage provided categories that could be used to explore the themes of the data. Additionally, to ensure thematic saturation, transcripts of observed simulated learning encounters were then analysed. Results: Six themes were established at the axial coding level, i.e., analytical skills, personal behaviours, communication, teamwork, context, and pedagogy. Underlying these themes, two principal concepts emerged, namely: intergroup contact anxiety – as both a result of and determinant of communication – and teamwork, both of which must be considered in relation to context. These concepts have subsequently been used to propose a framework for NTS learning. Conclusions: This study highlights the role of intergroup contact anxiety and teamwork as factors in NTS behaviour and its dissipation through interprofessional simulation learning. Therefore, this should be a key consideration in NTS education. Future research is needed to consider the role of the affective non-technical attributes of intergroup contact anxiety and teamwork as focuses for education and determinants of safe behaviour

The Grizzly, April 4, 2000

Future Changes in Store for UC • Phi Beta Kappa Speaker Set to Arrive on April 6th • International Round Table Important for Student Input • Mail Boxes, Etc. the Place for all Your Copying Needs • Valedictorian and Salutatorian Announced • Letters to the Editor: Debate Disappointment; Bringing Culture to the Grizzly • Design Versus Darwinism, a New Twist on an Old Debate • Problems With Housing? Maybe it\u27s Something in the Air • Music Review: Jimmy Thackery and the Drivers • Softball Improves to 16-4 • UC Baseball Begins Defense of CC Title • Rocky Start for Ursinus Tennis • UC Lax: Prepared to Take the Challenge • Wrestling with the Books: A Full Pin • CC Honors • UC Tumblers Top Off Season at NCAA Championships • Ursinus Track Tackles Widener • Sports Profile: Matt Wiatrakhttps://digitalcommons.ursinus.edu/grizzlynews/1464/thumbnail.jp

Reply to van Hoorn: Converging lines of evidence

We agree with the comments by van Hoorn (1) on our critique (2): testing causal hypotheses about human behavior is a challenge (1, 3). Making progress requires specifying alternative hypotheses and then testing these hypotheses using diverse and converging lines of evidence. We have defended the hypothesis that social norms, which culturally coevolved with the institutions of large-scale societies including markets, influence economic decision-making. This hypothesis emerged from a larger set that we developed both at the outset of our project and as we went along. Our interdisciplinary team’s initial list of hypotheses included the idea that experimental games might spark an innate reciprocity module that would yield little variation across populations