The Hydrodynamic stripping of spheroids and disks

This thesis presents numerical simulations of the ablation of galaxies and stellar disks. A sub-grid turbulence model is used to improve the accuracy of the results. Firstly simulations of galactic ram pressure stripping are presented. A spherically symmetric galactic halo is subjected to a wind of a number of different Mach numbers, both with and without the turbulence model. The initial, instantaneous stripping is unaffected by the use of the turbulence model. The turbulence model leads to significantly greater levels of long term ablation, which is more consistent with what simple analytic calculations indicate, showing that the continual Kelvin-Helmholtz stripping plays a significant role in the ram pressure stripping and this is hidden by the finite resolution of simulations without turbulence models. Secondly the turbulence model is applied to galactic disk simulations. In high Mach number (∼ 15) rotating disks the turbulence generated from the internal stresses in the disk causes it to become unstable and erroneously expand in the z direction. This is not the case for lower Mach number disks, such as dwarf disk galaxies. Further developments are needed in turbulence modelling if disk galaxies are to be simulated in this way. Finally inviscid simulations of the interaction of a supernova remnant on a stellar disk are presented. The supernova remnant is simulated hydrodynamically as opposed to using analytical approximations which represents an improvement on previous models. A number of inclination angles of the disk are considered which is not possible with previous two dimensional simulations. Mass loss rates are calculated and compared to other competing processes. Similarly to disk galaxies, the inclination angle only has a large effect on the evolution when the disk is close to edge on. Edge on disks develop an asymmetry when the ablation period is less than the rotation period of the disk. Contamination of the disk with supernova material is also investigate and is found to be low (about one part in 200, 000 in the highest case), consistent with previous results

Asthma in Vermont Dairy Farmers

Introduction. Although 5.4% of the Vermont population participates in agriculture as an occupation, little data exists on the prevalence of asthma in Vermont dairy farmers, due to inadequate sample sizes. Previous studies have shown dairy farmers are at risk of respiratory illness due to unique exposures intrinsic to their occupation. We conducted a study to assess the prevalence of asthma in dairy farmers in Vermont, to understand rates among this population and potential occupational risks.Methods. We distributed a paper survey modeled after previously-validated surveys, such as the BRFSS, to farmers at Vermont Farmer Bureau meetings, farmers markets, and individual farmers through Cabot Creamery. Out of 309 distributed surveys, we received 176 completed surveys for a response rate of 57%.Results. Self-reported asthma rate in dairy farmers was 21% (22% in dairy only farmers), with 90% of these cases reported as confirmed by a doctor. Of non-dairy farmers, 11% self-reported experiencing asthma. Farming activities associated with exacerbation of asthma symptoms were milking, prepping or cleaning bedding, and haying. 31% of dairy-only farmers reported symptom exacerbations due to these occupational triggers.Conclusions. The prevalence of asthma in Vermont dairy farmers is one of the highest reported rates in any Vermont occupation. Our data suggest that certain occupational exposures may increase risk of asthma and warrant further study; certain farming practices were associated with exacerbation of respiratory symptoms in farmers diagnosed with asthma. These findings and further research can assist in development of health care and preventive health measures for farmers.https://scholarworks.uvm.edu/comphp_gallery/1238/thumbnail.jp

Y(2175): Distinguish Hybrid State from Higher Quarkonium

The possibility of Y(2175) as a $2{^3D_1}$ $s\bar{s}$ meson is studied. We study the decay of $2{^3D_1}$ $s\bar{s}$ from both the $^3P_0$ model and the flux tube model, and the results are similar in the two models. We show that the decay patterns of $1^{--}$ strangeonium hybrid and $2{^3D_1}$ $s\bar{s}$ are very different. The experimental search of the decay modes $KK$, $K^{*}K^{*}$, $K(1460)K$, $h_1(1380)\eta$ is suggested to distinguish the two pictures. Measuring the $K^{*}K^{*}$ partial width ratios is crucial to discriminate the $2{^3D_1}$ from the $3{^3S_1}$ $s\bar{s}$ assignment.Comment: 13 pages, 8 figure

Electromagnetic transitions of excited baryons in a deformed oscillator quark model

We study electromagnetic transitions of excited baryons in a deformed oscillator quark model, where baryon excited states are described as rotational bands of deformed intrinsic states. We describe all necessary tools to compute transition amplitudes in multipole basis, which are then related to the commonly used helicity amplitudes. We pay a special attention on the sign of the amplitudes as well as their absolute values by computing the photon and pion couplings simultaneously. We have found that the effect of deformation on the transition amplitudes is rather weak. The difficulty in reproducing the empirical amplitude of the Roper state is discussed.Comment: 29 pages, 3 figures, LaTeX2e, epsf.sty and AMSLaTeX package are required; typos corrected, published versio

Del discurso narrativo al discurso teatral: selección léxica en Cervantes y Tirso

This article analyzes the retextualization of La señora Cornelia, a Cervantes’ novel, that was carried out by Tirso de Molina in his comedy Quien da luego, da dos veces. Based on the concept of discursive tradition as a significant element of linguistic change, this paper studies how the same content is expressed by different or coincident lexical selections in both works as a result of the adaptation of the narrative molds to the dramatic molds. The linguistic choices determined by the diegetic character of the novel must adapt to the mimetic discourse of the comedy.En este artículo se analiza el proceso de refacción textual o retextualización de la novela corta cervantina La señora Cornelia que Tirso de Molina llevó a cabo en su comedia Quien da luego, da dos veces. Partiendo del concepto de tradición discursiva como elemento significativo del cambio lingüistico, se estudia el modo en que un mismo contenido se plasma a través de selecciones léxicas diferentes o coincidentes en cada una de las obras mencionadas como consecuencia del proceso que implica el paso de los moldes narrativos a los teatrales. Las preferencias determinadas por el carácter diegético de la novela han de adaptarse en la comedia al discurso mimético

DsJ(2860)D_{sJ}(2860) and DsJ(2715)D_{sJ}(2715)

Recently Babar Collaboration reported a new $c\bar{s}$ state $D_{sJ}(2860)$ and Belle Collaboration observed $D_{sJ}(2715)$. We investigate the strong decays of the excited $c\bar{s}$ states using the $^{3}P_{0}$ model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we tend to conclude: (1) $D_{sJ}(2715)$ is probably the $1^{-}(1^{3}D_{1})$ $c\bar{s}$ state although the $1^{-}(2^{3}S_{1})$ assignment is not completely excluded; (2) $D_{sJ}(2860)$ seems unlikely to be the $1^{-}(2^{3}S_{1})$ and $1^{-}(1^{3}D_{1})$ candidate; (3) $D_{sJ}(2860)$ as either a $0^{+}(2^{3}P_{0})$ or $3^{-}(1^{3}D_{3})$ $c\bar{s}$ state is consistent with the experimental data; (4) experimental search of $D_{sJ}(2860)$ in the channels $D_s\eta$, $DK^{*}$, $D^{*}K$ and $D_{s}^{*}\eta$ will be crucial to distinguish the above two possibilities.Comment: 18 pages, 7 figures, 2 tables. Some discussions added. The final version to appear at EPJ

Electromagnetic transition form factors and dilepton decay rates of nucleon resonances

Relativistic, kinematically complete phenomenological expressions for the dilepton decay rates of nucleon resonances with arbitrary spin and parity are derived in terms of the magnetic, electric, and Coulomb transition form factors. The dilepton decay rates of the nucleon resonances with masses below 2 GeV are estimated using the extended vector meson dominance model for the transition form factors. The model provides a unified description of the photo- and electroproduction data, the vector meson decays, and the dilepton decays of the nucleon resonances. The constraints on the transition form factors from the quark counting rules are taken into account. The parameters of the model are fixed by fitting the available photo- and electroproduction data and using results of the multichannel partial-wave analysis of the $\pi N$ scattering. Where experimental data are not available, predictions of the non-relativistic quark models are used as an input. The vector meson coupling constants of the magnetic, electric, and Coulomb types are determined. The dilepton widths and the dilepton spectra from decays of nucleon resonances with masses below 2 GeV are calculated.Comment: An error in the code is found and fixed. Numerical results for the spin-half nucleon resonances changed. A few misprints are removed from the text. 56 pages including 7 tables and 27 eps figures, REVTe

Daily energy requirements of male academy soccer players are greater than age-matched non-academy soccer players: A doubly labelled water investigation

This study aimed to test the hypothesis that the total daily energy expenditure (TDEE) of male academy soccer players is greater than players not enrolled on a formalised academy programme. English Premier League academy (ACAD: n = 8, 13 years, 50 ± 6 kg, 88 ± 3% predicted adult stature, PAS) and non-academy players (NON-ACAD: n = 6, 13 years, 53 ± 12 kg, 89 ± 3% PAS) were assessed for TDEE (via doubly labelled water) during a 14-day in-season period. External loading was evaluated during training (ACAD: 8 sessions, NON-ACAD: 2 sessions) and games (2 games for both ACAD and NON-ACAD) via GPS, and daily physical activity was evaluated using triaxial accelerometry. Accumulative duration of soccer activity (ACAD: 975 ± 23 min, NON-ACAD: 397 ± 2 min; p < 0.01), distance covered (ACAD: 54.2 ± 8.3 km, NON-ACAD: 21.6 ± 4.7 km; p < 0.05) and time engaged in daily moderate-to-vigorous (ACAD: 124 ± 17 min, NON-ACAD: 79 ± 18 min; p < 0.01) activity was greater in academy players. Academy players displayed greater absolute (ACAD: 3380 ± 517 kcal · d−1, NON-ACAD: 2641 ± 308 kcal · d−1; p < 0.05) and relative TDEE (ACAD: 66 ± 6 kcal · kg · d−1, NON-ACAD: 52 ± 10 kcal · kg · d−1; p < 0.05) versus non-academy players. Given the injury risk associated with high training volumes during growth and maturation, data demonstrate the requirement for academy players to consume sufficient energy (and carbohydrate) intake to support the enhanced energy cost of academy programmes

Montmorency cherry juice reduces muscle damage caused by intensive strength exercise.

addresses: Sports and Exercise Science Research Centre, London South Bank University, London, United Kingdom. [email protected]: Clinical Trial; Journal Article; Research Support, Non-U.S. Gov'tThis is a non-final version of an article published in final form in Medicine and Science in Sports and Exercise, 2011, Vol. 43, Issue 8, pp. 1544 – 1551. © 2011 American College of Sports Medicine (ACSM)Montmorency cherries contain high levels of polyphenolic compounds including flavonoids and anthocyanins possessing antioxidant and anti-inflammatory effects. We investigated whether the effects of intensive unilateral leg exercise on oxidative damage and muscle function were attenuated by consumption of a Montmorency cherry juice concentrate using a crossover experimental design