178 research outputs found

    Reducing anterior cruciate ligament injury risk factors by training perception: How vital is maintaining the perception-action coupling?

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    This study investigated the effect of maintaining perception-action coupling during a 4-week perceptual training program aiming to reduce biomechanical risk factors associated with ACL injury. Kinetic (valgus and internal rotation knee moments) and neuromuscular (total knee muscle activation and directed co-contraction ratios) variables were calculated during evasive sidestepping of 3D-projected opponents in 1-on-1, 2-on-2 and 3-on-3 game-based situations pre and post-intervention training. An additional transfer scenario was assessed post-intervention. Twenty-six amateur Australian Rules footballers were allocated to control (C), uncoupled (U) or coupled (PA) groups. Participants completed biweekly perceptual training containing 48 trials requiring a verbal (uncoupled) or running sidestep (coupled) response while counting the number of attentional cues displayed. Training groups showed no reductions in peak valgus and internal rotation moments, however, a small decrease in peak valgus moments was observed in the transfer condition. Coupled training displayed significant group differences in medial-lateral co-contraction ratios from controls. No changes in muscle activation patterns pre-post ARF were observed, however C and UC groups redirected co-contraction ratios laterally in the transfer condition. Results suggest that attentional cueing perceptual training with a coupled response may have a beneficial impact on kinetic ACL injury risk factors and maintain muscle activation levels associated with decreased ACL injury risk

    Effects of a lifestyle intervention on endothelial function in men on long-term androgen deprivation therapy for prostate cancer

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    Background: Treatment of prostate cancer with androgen deprivation therapy (ADT) is associated with metabolic changes that have been linked to an increase in cardiovascular risk. Methods: This randomised controlled trial investigated the effects of a 12-week lifestyle intervention that included supervised exercise training and dietary advice on markers of cardiovascular risk in 50 men on long-term ADT recruited to an on-going study investigating the effects of such a lifestyle intervention on quality of life. Participants were randomly allocated to receive the intervention or usual care. Cardiovascular outcomes included endothelial function (flow-mediated dilatation [FMD] of the brachial artery), blood pressure, body composition and serum lipids. Additional outcomes included treadmill walk time and exercise and dietary behaviours. Outcomes were assessed before randomisation [baseline], and 6, 12 and 24 weeks after randomisation. Results: At 12 weeks the difference in mean relative FMD was 2.2% (95% CI 0.1 to 4.3, p = 0.04) with an effect size of 0.60 (95% CI <0.01 to 1.18) favouring the intervention group. Improvements in skeletal muscle mass, treadmill walk time and exercise behaviour also occurred in the intervention group over that duration (p < 0.05). At 24 weeks, only the difference in treadmill walk time was maintained. Conclusion: This study demonstrates that lifestyle changes can improve endothelial function in men on long-term ADT for prostate cancer. The implications for cardiovascular health need further investigation in larger studies over longer duration

    Auroral radio emission from late L and T dwarfs: A new constraint on dynamo theory in the substellar regime

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    We have observed six late L and T dwarfs with the Karl G. Jansky Very Large Array (VLA) to investigate the presence of highly circularly polarized radio emission, associated with large-scale auroral currents. Previous surveys encompassing ~60 L6 or later targets have yielded only one detection. Our sample includes the previously detected T6.5 dwarf 2MASS 10475385+2124234, as well as five new targets selected for the presence of Hα emission and/or optical infrared photometric variability, which are possible manifestations of auroral activity. We detect 2MASS 10475385+2124234, as well as four of the five targets in our biased sample, including the strong IR-variable source SIMP J01365662+0933473 and bright Hα emitter 2MASS 12373919+6526148, reinforcing the possibility that activity at these disparate wavelengths is related. The radio emission frequency corresponds to a precise determination of the lower-bound magnetic field strength near the surface of each dwarf, and this new sample provides robust constraints on dynamo theory in the low-mass brown dwarf regime. Magnetic fields ≳2.5 kG are confirmed for five of six targets. Our results provide tentative evidence that the dynamo operating in this mass regime may be inconsistent with predicted values from a recently proposed model. Further observations at higher radio frequencies are essential for verifying this assertion

    SN 2007gr: a Normal Type Ic Supernova with a Mildly Relativistic Radio Jet?

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    A nearby type Ic supernova, SN 2007gr was observed with the EVN in two epochs 60 days apart (second observation also included the Green Bank Telescope). In both cases one of the EVN stations was the Westerbork Synthesis Radio Telescope (WSRT), which recorded the observational data not only in the VLBI mode, but also in its normal interferometric mode. Thus it provided an important reference observation. In the first epoch the fluxes measured by the VLBI network and the WSRT alone match well. However in the second epoch the peak brightness observed in the VLBI experiment is much lower than the total flux recorded by the WSRT. There could be multiple reasons for this discrepancy: a resolution effect, coherence losses in VLBI, or extended emission contaminating the WSRT measurement. With new WSRT observations we costrain the level of background emission and find that there is still a difference between the corrected total flux density and the VLBI peak brightness. If one assumes that this is dominated by resolution, this would correspond to an average apparent expansion speed of ~0.4c

    A simultaneous search for prompt radio emission associated with the short GRB 170112A using the all-sky imaging capability of the OVRO-LWA

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    We have conducted the most sensitive low frequency (below 100 MHz) search to date for prompt, low-frequency radio emission associated with short-duration gamma-ray bursts (GRBs), using the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA). The OVRO-LWA's nearly full-hemisphere field-of-view (∼20\sim20,000000 square degrees) allows us to search for low-frequency (sub-100100 MHz) counterparts for a large sample of the subset of GRB events for which prompt radio emission has been predicted. Following the detection of short GRB 170112A by Swift, we used all-sky OVRO-LWA images spanning one hour prior to and two hours following the GRB event to search for a transient source coincident with the position of GRB 170112A. We detect no transient source, with our most constraining 1σ1\sigma flux density limit of 650 mJy650~\text{mJy} for frequencies spanning 27 MHz−84 MHz27~\text{MHz}-84~\text{MHz}. We place constraints on a number of models predicting prompt, low-frequency radio emission accompanying short GRBs and their potential binary neutron star merger progenitors, and place an upper limit of Lradio/Lγ≲7×10−16L_\text{radio}/L_\gamma \lesssim 7\times10^{-16} on the fraction of energy released in the prompt radio emission. These observations serve as a pilot effort for a program targeting a wider sample of both short and long GRBs with the OVRO-LWA, including bursts with confirmed redshift measurements which are critical to placing the most constraining limits on prompt radio emission models, as well as a program for the follow-up of gravitational wave compact binary coalescence events detected by advanced LIGO and Virgo.Comment: 14 pages, 5 figures, ApJ submitte

    The Mannose Receptor (CD206) is an important pattern recognition receptor (PRR) in the detection of the infective stage of the helminth Schistosoma mansoni and modulates IFNγ production.

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    In this study, infective larvae of the parasitic helminth Schistosoma mansoni were shown to contain a large number of glycosylated components specific for the Mannose Receptor (MR; CD206), which is an important pattern recognition receptor (PRR) of the innate immune system. MR ligands were particularly rich in excretory/secretory (E/S) material released during transformation of cercariae into schistosomula, a process critical for infection of the host. E/S material from carboxyfluorescein diacetate succinimidyl ester (CFDA-SE)-labelled cercariae showed enhanced binding by cells lines that over-express the MR. Conversely, uptake was significantly lower by bone marrow-derived macrophages (MΦ) from MR(-/-) mice, although they were more active as judged by enhanced pro-inflammatory cytokine production and CD40 expression. After natural percutaneous infection of MR(-/-) mice with CFDA-SE-labelled parasites, there were fewer cells in the skin and draining lymph nodes that were CFDA-SE(+) compared with wild-type mice, implying reduced uptake and presentation of larval parasite antigen. However, antigen-specific proliferation of skin draining lymph node cells was significantly enhanced and they secreted markedly elevated levels of IFNγ but decreased levels of IL-4. In conclusion, we show that the MR on mononuclear phagocytic cells, which are plentiful in the skin, plays a significant role in internalising E/S material released by the invasive stages of the parasite which in turn modulates their production of pro-inflammatory cytokines. In the absence of the MR, antigen-specific CD4(+) cells are Th1 biased, suggesting that ligation of the MR by glycosylated E/S material released by schistosome larvae modulates the production of CD4(+) cell specific IFNγ

    Initiation of Psychotropic Medication after Partner Bereavement: A Matched Cohort Study

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    Background Recent changes to diagnostic criteria for depression in DSM-5 remove the bereavement exclusion, allowing earlier diagnosis following bereavement. Evaluation of the potential effect of this change requires an understanding of existing psychotropic medication prescribing by non-specialists after bereavement. Aims To describe initiation of psychotropic medication in the first year after partner bereavement. Methods In a UK primary care database, we identified 21,122 individuals aged 60 and over with partner bereavement and no psychotropic drug use in the previous year. Prescribing (anxiolytic/hypnotic, antidepressant, antipsychotic) after bereavement was compared to age, sex and practice matched controls. Results The risks of receiving a new psychotropic prescription within two and twelve months of bereavement were 9.5% (95% CI 9.1 to 9.9%) and 17.9% (17.3 to 18.4%) respectively; an excess risk of initiation in the first year of 12.4% compared to non-bereaved controls. Anxiolytic/hypnotic and antidepressant initiation rates were highest in the first two months. In this period, the hazard ratio for initiation of anxiolytics/hypnotics was 16.7 (95% CI 14.7 to 18.9) and for antidepressants was 5.6 (4.7 to 6.7) compared to non-bereaved controls. 13.3% of those started on anxiolytics/hypnotics within two months continued to receive this drug class at one year. The marked variation in background family practice prescribing of anxiolytics/hypnotics was the strongest determinant of their initiation in the first two months after bereavement. Conclusion Almost one in five older people received a new psychotropic drug prescription in the year after bereavement. The early increase and trend in antidepressant use after bereavement suggests some clinicians did not adhere to the bereavement exclusion, with implications for its recent removal in DSM-5. Family practice variation in use of anxiolytics/hypnotics suggests uncertainty over their role in bereavement with the potential for inappropriate long term use

    Survivorship and improving quality of life in men with prostate cancer

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    Context: Long-term survival following a diagnosis of cancer is improving in developed nations. However, living longer does not necessarily equate to living well. Objective: To search systematically and synthesise narratively the evidence from randomised controlled trials (RCTs) of supportive interventions designed to improve prostate cancer (PCa)-specific quality of life (QoL). Evidence acquisition: A systematic search of Medline and Embase was carried out from inception to July 2014 to identify interventions targeting PCa QoL outcomes. We did not include nonrandomised studies or trials of mixed cancer groups. In addition to database searches, citations from included papers were hand-searched for any potentially eligible trials. Evidence synthesis: A total of 2654 PCa survivors from 20 eligible RCTs were identified from our database searches and reference checks. Disease-specific QoL was assessed most frequently by the Functional Assessment of Cancer Therapy-Prostate questionnaire. Included studies involved men across all stages of disease. Supportive interventions that featured individually tailored approaches and supportive interaction with dedicated staff produced the most convincing evidence of a benefit for PCa-specific QoL. Much of these data come from lifestyle interventions. Our review found little supportive evidence for simple literature provision (either in booklets or via online platforms) or cognitive behavioural approaches. Conclusions: Physical and psychological health problems can have a serious negative impact on QoL in PCa survivors. Individually tailored supportive interventions such as exercise prescription/referral should be considered by multidisciplinary clinical teams where available. Cost-effectiveness data and an understanding of how to sustain benefits over the long term are important areas for future research. Patient summary: This review of supportive interventions for improving quality of life in prostate cancer survivors found that supervised and individually tailored patient-centred interventions such as lifestyle programmes are of benefit.</p
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