269 research outputs found
Assessment of contact involvements and scrums in international rugby union match-play using video analysis and microsensor technology methods
This study sought to assess the validity of contact involvement (CI) detection using microsensor technology (MST, Catapult Vector) within the context of a Tier One national rugby union (RU) squad, consisting of 44 players. Sensitivity of MST units to detect CI and scrums was assessed in eight test matches, by comparison with match data obtained by video analysis. This paper is the first to assess the sensitivity of MST to the full range of skilled CI which occur in RU, including evaluating “non-performance” collisions, such as incidental collisions or foul play. Sensitivity to tackles made (52.9–84.9%) and ruck hits (53.3–87.2%) was lower than previous research, although ball carries (71.9–93.5%) showed broadly similar sensitivity to established results. The sensitivity of the MST to detect scrums was substantially lower than previous findings, with large positional variation evident (51.4–91.5%). Further refinement of MST software should be considered in order to facilitate valid monitoring of RU performance and injury risk. An additional finding was that video analysis generally demonstrated satisfactory intrarater reliability. This result supports the use of video analysis as a reliable method of assessing RU performance, including CI
The Yellow Supergiant Progenitor of the Type II Supernova 2011dh in M51
We present the detection of the progenitor of the Type II SN 2011dh in
archival pre-explosion Hubble Space Telescope images. Using post-explosion
Adaptive Optics imaging with Gemini NIRI+ALTAIR, the position of the SN in the
pre-explosion images was determined to within 23mas. The progenitor object was
found to be consistent with a F8 supergiant star (log L/L_{\odot}=4.92+/-0.20
and T_{eff}=6000+/-280K). Through comparison with stellar evolution tracks,
this corresponds to a single star at the end of core C-burning with an initial
mass of M_{ZAMS}=13+/-3M_{\odot}. The possibility of the progenitor source
being a cluster is rejected, on the basis of: 1) the source is not spatially
extended; 2) the absence of excess H\alpha\, emission; and 3) the poor fit to
synthetic cluster SEDs. It is unclear if a binary companion is contributing to
the observed SED, although given the excellent correspondence of the observed
photometry to a single star SED we suggest the companion does not contribute
significantly. Early photometric and spectroscopic observations show fast
evolution similar to the transitional Type IIb SN 2008ax, and suggest that a
large amount of the progenitor's hydrogen envelope was removed before
explosion.Comment: Submitted to ApJ Letters - 6 pages, 5 figure
Long period variables in 47 Tuc: direct evidence for lost mass
We have identified 22 new variable red giants in 47 Tuc and determined
periods for another 8 previously known variables. All red giants redder than
V-I_c=1.8 are variable at the limits of our detection threshold, which
corresponds to delta V ~ 0.1 mag. This colour limit corresponds to a luminosity
log L/L_sun=3.15 and it is considerably below the tip of the RGB at log
L/L_sun=3.35. Linear non-adiabatic models without mass loss on the giant branch
can not reproduce the observed PL laws for the low amplitude pulsators. Models
that have undergone mass loss do reproduce the observed PL relations and they
show that mass loss of the order of 0.3 M_sun occurs along the RGB and AGB. The
linear pulsation periods do not agree well with the observed periods of the
large amplitude Mira variables, which pulsate in the fundamental mode. The
solution to this problem appears to be that the nonlinear pulsation periods in
these low mass stars are considerably shorter than the linear pulsation periods
due to a rearrangement of stellar structure caused by the pulsation. Both
observations and theory show that stars evolve up the RGB and first part of the
AGB pulsating in low order overtone modes, then switch to fundamental mode at
high luminosities.Comment: 11 pages, accepted for publication in A&
Design and Synthesis of Broad Spectrum Trypanosomatid Selective Inhibitors
Neglected
tropical diseases caused by parasitic infections are an ongoing and
increasing concern that have a devastating effect on the developing
world due to their burden on human and animal health. In this work,
we detail the preparation of a focused library of substituted-tetrahydropyran
derivatives and their evaluation as selective chemical tools for trypanosomatid
inhibition and the follow-on development of photoaffinity probes capable
of labeling target protein(s) <i>in vitro</i>. Several of
these functionalized compounds maintain low micromolar activity against <i>Trypanosoma brucei</i>, <i>Trypanosoma cruzi</i>, <i>Leishmania major</i>, and <i>Leishmania donovani</i>. In addition, we demonstrate the utility of the photoaffinity probes
for target identification through preliminary cellular localization
studies
Referrals for positive tuberculin tests in new health care workers and students: a retrospective cohort study
<p>Abstract</p> <p>Background</p> <p>Documentation of test results for latent tuberculosis (TB) infection is important for health care workers and students before they begin work. A negative result provides a baseline for comparison with future tests. A positive result affords a potential opportunity for treatment of latent infection when appropriate. We sought to evaluate the yield of the referral process for positive baseline tuberculin tests, among persons beginning health care work or studies.</p> <p>Methods</p> <p>Retrospective cohort study. We reviewed the charts of all new health care students and workers referred to the Montreal Chest Institute in 2006 for positive baseline tuberculin skin tests (≥10 mm). Health care workers and students evaluated for reasons other than positive baseline test results were excluded.</p> <p>Results</p> <p>630 health care students and workers were evaluated. 546 (87%) were foreign-born, and 443 (70%) reported previous Bacille Calmette-Guérin (BCG) vaccination. 420 (67%) were discharged after their first evaluation without further treatment. 210 (33%) were recommended treatment for latent TB infection, of whom 165 (79%) began it; of these, 115 (70%) completed adequate treatment with isoniazid or rifampin. Treatment discontinuation or interruption occurred in a third of treated subjects, and most often reflected loss to follow-up, or abdominal discomfort. No worker or student had active TB.</p> <p>Conclusions</p> <p>Only a small proportion of health care workers and students with positive baseline tuberculin tests were eligible for, and completed treatment for latent TB infection. We discuss recommendations for improving the referral process, so as to better target workers and students who require specialist evaluation and treatment for latent TB infection. Treatment adherence also needs improvement.</p
AGB Variables and the Mira Period-Luminosity Relation
Published data for large amplitude asymptotic giant branch variables in the
Large Magellanic Cloud are re-analysed to establish the constants for an
infrared (K) period-luminosity relation of the form: Mk=rho[log P-2.38] +
delta. A slope of rho=-3.51+/-0.20 and a zero point of delta=-7.15+/-0.06 are
found for oxygen-rich Miras (if a distance modulus of 18.39+/-0.05 is used for
the LMC). Assuming this slope is applicable to Galactic Miras we discuss the
zero-point for these stars using the revised Hipparcos parallaxes together with
published VLBI parallaxes for OH Masers and Miras in Globular Clusters. These
result in a mean zero-point of delta=-7.25+/-0.07 for O-rich Galactic Miras.
The zero-point for Miras in the Galactic Bulge is not significantly different
from this value.
Carbon-rich stars are also discussed and provide results that are consistent
with the above numbers, but with higher uncertainties. Within the uncertainties
there is no evidence for a significant difference between the period-luminosity
relation zero-points for systems with different metallicity.Comment: 15 pages, 3 figures, accepted for MNRA
European badger (Meles meles) responses to low-intensity, selective culling: using mark recapture and relatedness data to assess social perturbation
Publication history: Accepted - 20 June 2022; Published online - 28 July 2022Culling the main wildlife host of bovine tuberculosis in Great Britain (GB) and Ireland, the European badger (Meles meles), has been employed in both territories to reduce infections in cattle. In GB, this has been controversial, with results suggesting that culling induces disturbance to badger social structure, facilitating wider disease dissemination. Previous analyses hypothesized that even very low-level, selective culling may cause similar deleterious effects by increasing ranging of individuals and greater mixing between social groups.
To assess this hypothesis, a novel, prospective, landscape-scale ‘before-and-after’ Test and Vaccinate or Remove (TVR) study was implemented. Test-positive badgers were culled and test-negative badgers were Bacillus Calmette–Guérin (BCG) vaccinated and released.
Mark–recapture metrics of badger ranging and genetic metrics of social group relatedness did not change significantly over the study period. However, selective culling was associated with a localized reduction in social group relatedness in culled groups.
Ecological context is important; extrapolation across territories and other disease epidemiological systems (epi-systems) is likely to be challenging. However, we demonstrate that small-scale, selective removal of test-positive badgers was not associated with metrics of increased ranging but was associated with localized changes in social group relatedness. This adds to the evidence base on badger control options for policy makers.Department of Agriculture, Environment and Rural Affairs (DAERA) N
Genomic epidemiology of Mycobacterium bovis infection in sympatric badger and cattle populations in Northern Ireland
Bovine tuberculosis (bTB) is a costly, epidemiologically complex, multi-host, endemic disease. Lack of understanding of transmission dynamics may undermine eradication efforts. Pathogen whole-genome sequencing improves epidemiological inferences, providing a means to determine the relative importance of inter- and intra-species host transmission for disease persistence. We sequenced an exceptional data set of 619 Mycobacterium bovis isolates from badgers and cattle in a 100 km2 bTB 'hotspot' in Northern Ireland. Historical molecular subtyping data permitted the targeting of an endemic pathogen lineage, whose long-term persistence provided a unique opportunity to study disease transmission dynamics in unparalleled detail. Additionally, to assess whether badger population genetic structure was associated with the spatial distribution of pathogen genetic diversity, we microsatellite genotyped hair samples from 769 badgers trapped in this area. Birth death models and TransPhylo analyses indicated that cattle were likely driving the local epidemic, with transmission from cattle to badgers being more common than badger to cattle. Furthermore, the presence of significant badger population genetic structure in the landscape was not associated with the spatial distribution of M. bovis genetic diversity, suggesting that badger-to-badger transmission is not playing a major role in transmission dynamics. Our data were consistent with badgers playing a smaller role in transmission of M. bovis infection in this study site, compared to cattle. We hypothesize, however, that this minor role may still be important for persistence. Comparison to other areas suggests that M. bovis transmission dynamics are likely to be context dependent, with the role of wildlife being difficult to generalize.ISSN:2057-585
OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary Lens
We present the analysis result of a gravitational binary-lensing event
OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent
strong features and a single weak feature separated from the strong features.
The light curve exhibits noticeable deviations from the best-fit model based on
standard binary parameters. To explain the deviation, we test models including
various higher-order effects of the motions of the observer, source, and lens.
From this, we find that it is necessary to account for the orbital motion of
the lens in describing the light curve. From modeling of the light curve
considering the parallax effect and Keplerian orbital motion, we are able to
measure not only the physical parameters but also a complete orbital solution
of the lens system. It is found that the event was produced by a binary lens
located in the Galactic bulge with a distance kpc from the Earth.
The individual lens components with masses and are separated with a semi-major axis of AU and
orbiting each other with a period yr. The event demonstrates
that it is possible to extract detailed information about binary lens systems
from well-resolved lensing light curves.Comment: 19 pages, 6 figure
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