2,518 research outputs found

    Reliability of shoulder rotators isometric strength test using a novel pulley electromechanical dynamometer. Influence of the assessment position

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    Indexación: Scopus.Background: The shoulder complex, because of its relatively extensive freedom of motion, offers a great variety of testing positions and articular planes for strength examination. Despite this, reliability of results are not clearly addressed. A novel pulley electromechanical dynamometer (FED) (functional electronic dynamometer) could be an alternative in strength assessment, however, the relative and absolute reliability have not been reported in the literature. Objectives: To report the results of shoulder internal (IR) and rotators (ER) peak torque reliability in two assessment positions by FED in asymptomatic subjects. Methods: Fifty-two healthy college students were included and tested twice within a two week period. In a supine position, the subjects randomly performed four isometric strength tests (i.e. IR at 40°, IR at 90°, ER at 40°, and ER at 90° of shoulder abduction). Results: The intra-class correlation coefficients (ICC) for relative reliability at 90° were 0.96 (0.94-0.98) for IR and 0.94 (0.90-0.96) for ER. ICC at 40° were 0.89 (0.80-0.94) for IR and 0.97 (0.94-0.98) for ER. Absolute reliability expressed as standard error of measurement compared to the mean (SEM%) and 95% confidence interval (CI) of minimal detectable change percentage (MDC%) at 90° were 8.8% (-20.8, 28.4%) and 11.4% (-28.0, 35.2%) for ER. MDC% at 40° were 12.6% (-35.5, 34.8%) for IR and 18.1% (-28.1, 35, 2%) for ER. Conclusions: Isometric strength testing protocol using FED showed an excellent reproducibility and can be safely used in clinical settings to monitor the strength changes in a group of individuals or in a single individual. © 2018, Asian Journal of Sports Medicine.http://asjsm.com/en/articles/60406.htm

    Predictions for Triple Stars with and without a Pulsar in Star Clusters

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    Though about 80 pulsar binaries have been detected in globular clusters so far, no pulsar has been found in a triple system in which all three objects are of comparable mass. Here we present predictions for the abundance of such triple systems, and for the most likely characteristics of these systems. Our predictions are based on an extensive set of more than 500 direct simulations of star clusters with primordial binaries, and a number of additional runs containing primordial triples. Our simulations employ a number N_{tot} of equal mass stars from N_{tot}=512 to N_{tot}=19661 and a primordial binary fraction from 0-50%. In addition, we validate our results against simulations with N=19661 that include a mass spectrum with a turn-off mass at 0.8 M_{sun}, appropriate to describe the old stellar populations of galactic globular clusters. Based on our simulations, we expect that typical triple abundances in the core of a dense cluster are two orders of magnitude lower than the binary abundances, which in itself already suggests that we don't have to wait too long for the first comparable-mass triple with a pulsar to be detected.Comment: 11 pages, minor changes to match MNRAS accepted versio

    Identification and characterization of Rhipicephalus (Boophilus) microplus candidate protective antigens for the control of cattle tick infestations

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    The cattle ticks, Rhipicephalus (Boophilus) spp., affect cattle production in tropical and subtropical regions of the world. Tick vaccines constitute a cost-effective and environmentally friendly alternative to tick control. The recombinant Rhipicephalus microplus Bm86 antigen has been shown to protect cattle against tick infestations. However, variable efficacy of Bm86-based vaccines against geographic tick strains has encouraged the research for additional tick-protective antigens. Herein, we describe the analysis of R. microplus glutathione-S transferase, ubiquitin (UBQ), selenoprotein W, elongation factor-1 alpha, and subolesin (SUB) complementary DNAs (cDNAs) by RNA interference (RNAi) in R. microplus and Rhipicephalus annulatus. Candidate protective antigens were selected for vaccination experiments based on the effect of gene knockdown on tick mortality, feeding, and fertility. Two cDNA clones encoding for UBQ and SUB were used for cattle vaccination and infestation with R. microplus and R. annulatus. Control groups were immunized with recombinant Bm86 or adjuvant/saline. The highest vaccine efficacy for the control of tick infestations was obtained for Bm86. Although with low immunogenic response, the results with the SUB vaccine encourage further investigations on the use of recombinant subolesin alone or in combination with other antigens for the control of cattle tick infestations. The UBQ peptide showed low immunogenicity, and the results of the vaccination trial were inconclusive to assess the protective efficacy of this antigen. These experiments showed that RNAi could be used for the selection of candidate tick-protective antigens. However, vaccination trials are necessary to evaluate the effect of recombinant antigens in the control of tick infestations, a process that requires efficient recombinant protein production and formulation systems

    Video-based biomechanical analysis of an unexpected Achilles tendon rupture in an Olympic sprinter

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    We used image-processing techniques to determine the moment (i.e., image frame) of the Achilles tendon (AT) rupture in an Olympic sprinter. This report may be unique due to the difficulty in conducting motion capture analyses during injury events. Our report includes one female Olympic sprinter, 29 years old (body mass: 56 kg, height: 1.68 m, and body mass index: 19.8 kg/m2) with a high-competitive profile history (2008 and 2012 Olympic Games participation; South American record holder in 100- and 200-m; Pan-American gold medalist in 200-m and 4 x 100-m relay) who suffered a complete AT rupture in the left leg while exercising in the final phase of rehabilitation following an Achilles tendinopathy in the contralateral limb. The greater dorsiflexion found at the moment of the injury and the delayed control of heel position indicated the presence of uncontrolled dorsiflexion, which potentially generated excessive eccentric stress over the tendon and, thus, the AT rupture. Here we discuss the relevance of lower leg alignment, the movements’ characteristics, and the history of Achilles tendinopathy in the contralateral leg on the occurrence of the AT rupture

    NGC2180: a disrupting open cluster

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    The spatial dependence of luminosity and mass functions of evolved open clusters is discussed in this work using J and H 2MASS photometry. The target objects are the overlooked open cluster NGC2180 and the intermediate-age open cluster NGC3680. We conclude that, although in an advanced dynamical state (mass segregated), NGC3680 does not present strong signs of dissolution. On the other hand, NGC2180 presents flat, eroded LFs throughout its structure, indicating that in addition to mass segregation, Galactic tidal stripping has been effective in depleting this cluster of stars. Accordingly, NGC2180 may be the missing link between evolved open clusters and remnants. We study both clusters in the context of dynamical states estimated from diagnostic-diagrams involving photometric and structural parameters. Both clusters are dynamically evolved systems. In particular, NGC2180 is closer to open cluster remnants than NGC3680.Comment: 9 pages, 8 figure

    Dissolving star cluster candidates

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    We present a list of 34 neglected entries from star cluster catalogues located at relatively high galactic latitudes (∣b∣>|b| > 15∘^{\circ}) which appear to be candidate late stages of star cluster dynamical evolution. Although underpopulated with respect to usual open clusters, they still present a high number density contrast as compared to the galactic field. This was verified by means of (i) predicted model counts from different galactic subsystems in the same direction, and (ii) Guide Star Catalog equal solid angle counts for the object and surrounding fields. This suggests that the objects are physical systems, possibly star clusters in the process of disruption or their fossil remains. The sample will be useful for followup studies in view of verifying their physi cal nature.Comment: manuscript in LATEX with 7 pages, 7 figures .ps Accepted for Astronomy and Astrophysics main journa
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