604 research outputs found

    Effects of fatigue on muscle activation and shock attenuation during barefoot running

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    Lately, barefoot running has received attention from many acknowledged researchers and athletes alike. If alterations in running mechanics related to fatigue are found to be different while running barefoot, it may help to identify the practicality and efficacy of barefoot running in terms of injury prevention. PURPOSE: The purpose of this study was to investigate the effect of global fatigue on muscle activation and the rate of shock attenuation during barefoot (BFT) and shod (SHD) running in habitually shod runners. METHODS: Eleven well-trained runners were recruited from the community to complete protocols in two different footwear conditions (BFT and SHD). Each condition consisted of two instrumented 100-meter run trials (pre- and postfatigue) where data for the rate of tibial acceleration (RA) and preactivation iEMG of the tibialis anterior (TA) and medial gastrocnemius (MG) were gathered. Between each trial, subjects completed a 30-minute maximal effort fatiguing run in shoes on an outdoor running track. The two conditions differed only in footwear donned for the instrumented trials, were separated by 3- 7 days, and were preceded by 36 hours of non-exercise rest to reduce confounding fatigue. Three two-by-two repeated measures ANOVAs with factors Time (pre, post) and Footwear (BFT, SHD) were applied with an alpha level of 0.05. RESULTS: The results revealed a significant difference for RA based on condition. BFT yielded higher acceleration rates than SHD (1646.64 g/s vs. 650.93 g/s; p \u3c 0.001). RA for both conditions remained unchanged following fatigue, showing an equal ability to attenuate impact shock. TA iEMG responded differently to fatigue based on condition, according to a significant interaction observed (p = 0.031). Following fatigue, TA iEMG increased by 8.66% SHD and decreased by 12.54% BFT (p = 0.015). MG iEMG revealed no significant effect of time or footwear, acting in a similar fashion in all trials. CONCLUSION: Our data indicate that runners may adopt different shank muscle coordination strategies while running barefoot and shod. In addition, these strategies appear to be affected differently by fatigue in order to adequately attenuate impact shock. It may be suggested to approach barefoot running with caution, especially when an athlete is in a fatigued state

    Evaluating the long-term effectiveness of school-based depression, anxiety, and substance use prevention into young adulthood: Protocol for the climate school combined study

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    Background: Mental health and substance use disorders are the leading causes of global disability in children and youth. Both tend to first onset or escalate in adolescence and young adulthood, calling for effective prevention during this time. The Climate Schools Combined (CSC) study was the first trial of a Web-based combined universal approach, delivered through school classes, to prevent both mental health and substance use problems in adolescence. There is also limited evidence for the cost-effectiveness of school-based prevention programs. Objective: The aim of this protocol paper is to describe the CSC follow-up study, which aims to determine the long-term efficacy and cost-effectiveness of the CSC prevention program for depression, anxiety, and substance use (alcohol and cannabis use) up to 7 years post intervention. Methods: A cluster randomized controlled trial (the CSC study) was conducted with 6411 participants aged approximately 13.5 years at baseline from 2014 to 2016. Participating schools were randomized to 1 of 4 conditions: (1) control (health education as usual), (2) Climate Substance Use (universal substance use prevention), (3) Climate Mental Health (universal mental health prevention), or (4) CSC (universal substance use and mental health prevention). It was hypothesized that the CSC program would be more effective than conditions (1) to (3) in reducing alcohol and cannabis use (and related harms), anxiety, and depression symptoms as well as increasing knowledge related to alcohol, cannabis, anxiety, and depression. This long-term study will invite follow-up participants to complete 3 additional Web-based assessments at approximately 5, 6, and 7 years post baseline using multiple sources of locator information already provided to the research team. The primary outcomes include alcohol and cannabis use (and related harms) and mental health symptoms. An economic evaluation of the program will also be conducted using both data linkage as well as self-report resource use and quality of life measures. Secondary outcomes include self-efficacy, social networks, peer substance use, emotion regulation, and perfectionism. Analyses will be conducted using multilevel mixed-effects models within an intention-to-treat framework. Results: The CSC long-term follow-up study is funded from 2018 to 2022 by the Australian National Health and Medical Research Council (APP1143555). The first follow-up wave commences in August 2018, and the results are expected to be submitted for publication in 2022. Conclusions: This is the first study to provide a long-term evaluation of combined universal substance use and mental health prevention up to 7 years post intervention. Evidence of sustained benefits into early adulthood would provide a scalable, easy-to-implement prevention strategy with the potential for widespread dissemination to reduce the considerable harms, burden of disease, injury, and social costs associated with youth substance use and mental disorders

    Evaluation of Phage Display Discovered Peptides as Ligands for Prostate-Specific Membrane Antigen (PSMA)

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    The aim of this study was to identify potential ligands of PSMA suitable for further development as novel PSMA-targeted peptides using phage display technology. The human PSMA protein was immobilized as a target followed by incubation with a 15-mer phage display random peptide library. After one round of prescreening and two rounds of screening, high-stringency screening at the third round of panning was performed to identify the highest affinity binders. Phages which had a specific binding activity to PSMA in human prostate cancer cells were isolated and the DNA corresponding to the 15-mers were sequenced to provide three consensus sequences: GDHSPFT, SHFSVGS and EVPRLSLLAVFL as well as other sequences that did not display consensus. Two of the peptide sequences deduced from DNA sequencing of binding phages, SHSFSVGSGDHSPFT and GRFLTGGTGRLLRIS were labeled with 5-carboxyfluorescein and shown to bind and co-internalize with PSMA on human prostate cancer cells by fluorescence microscopy. The high stringency requirements yielded peptides with affinities KD∼1 μM or greater which are suitable starting points for affinity maturation. While these values were less than anticipated, the high stringency did yield peptide sequences that apparently bound to different surfaces on PSMA. These peptide sequences could be the basis for further development of peptides for prostate cancer tumor imaging and therapy. © 2013 Shen et al

    TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844

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    Data from the newly-commissioned \textit{Transiting Exoplanet Survey Satellite} (TESS) has revealed a "hot Earth" around LHS 3844, an M dwarf located 15 pc away. The planet has a radius of 1.32±0.021.32\pm 0.02 RR_\oplus and orbits the star every 11 hours. Although the existence of an atmosphere around such a strongly irradiated planet is questionable, the star is bright enough (I=11.9I=11.9, K=9.1K=9.1) for this possibility to be investigated with transit and occultation spectroscopy. The star's brightness and the planet's short period will also facilitate the measurement of the planet's mass through Doppler spectroscopy.Comment: 10 pages, 4 figures. Submitted to ApJ Letters. This letter makes use of the TESS Alert data, which is currently in a beta test phase, using data from the pipelines at the TESS Science Office and at the TESS Science Processing Operations Cente

    A close examination of double filtering with fold change and t test in microarray analysis

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    <p>Abstract</p> <p>Background</p> <p>Many researchers use the double filtering procedure with fold change and <it>t </it>test to identify differentially expressed genes, in the hope that the double filtering will provide extra confidence in the results. Due to its simplicity, the double filtering procedure has been popular with applied researchers despite the development of more sophisticated methods.</p> <p>Results</p> <p>This paper, for the first time to our knowledge, provides theoretical insight on the drawback of the double filtering procedure. We show that fold change assumes all genes to have a common variance while <it>t </it>statistic assumes gene-specific variances. The two statistics are based on contradicting assumptions. Under the assumption that gene variances arise from a mixture of a common variance and gene-specific variances, we develop the theoretically most powerful likelihood ratio test statistic. We further demonstrate that the posterior inference based on a Bayesian mixture model and the widely used significance analysis of microarrays (SAM) statistic are better approximations to the likelihood ratio test than the double filtering procedure.</p> <p>Conclusion</p> <p>We demonstrate through hypothesis testing theory, simulation studies and real data examples, that well constructed shrinkage testing methods, which can be united under the mixture gene variance assumption, can considerably outperform the double filtering procedure.</p

    Earthworm activity and availability for meadow birds is restricted in intensively managed grasslands

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    Earthworms are an important prey for the endangered meadow birds of northwest Europe. Although intensive grassland management with high manure inputs generally promotes earthworm abundance, it may reduce the effective food availability for meadow birds through desiccation of the topsoil, which causes earthworms to remain deeper in the soil. We studied the response of Red Worm Lumbricus rubellus, a detritivore, and Grey Worm Aporrectodea caliginosa, a geophage, to soil moisture profiles in the field and under experimental conditions. Surfacing earthworms were counted weekly in eight intensively managed grasslands (treated with high inputs of slurry by slit injection) with variable groundwater tables in the Netherlands. At each count, soil penetration resistance, soil moisture tension and groundwater level were measured, while air temperature and humidity were obtained from a nearby weather station. The response to variation in the vertical distribution of soil moisture was also experimentally studied in the two earthworm species. In the field, earthworms’ surfacing activity at night was negatively associated with soil moisture tension and positively by relative air humidity. Surprisingly, there was no effect of groundwater level; an important management variable in meadow bird conservation. Under experimental conditions, both L. rubellus and A. caliginosa moved to deeper soil layers (&gt;20 cm) in drier soil moisture treatments, avoiding the upper layer when moisture levels dropped below 30%. Synthesis and applications. We propose that in intensively managed grasslands with slurry application, topsoil desiccation reduces earthworm availability for meadow birds. This can be counteracted by keeping soil moisture tensions of the top soil above −15 kPa. We suggest that the late raising of groundwater tables in spring and the disturbance of the soil by slit injection of slurry increase topsoil desiccation. This decreases earthworm availability when it matters most for breeding meadow birds. Meadow bird conservation will benefit from revised manure application strategies that promote earthworm activity near or at the soil surface.</p

    Kenai Fjords National Park: Exit Glacier Area: Summer Transportation Feasibility Study

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    VXU7A1/SE293VXU7A1/SE294The purpose of the Exit Glacier Area summer transportation feasibility study for Kenai Fjords National Park (KEFJ) is to understand the current transportation conditions at the Exit Glacier Area and evaluate the feasibility of a range of potential actions to improve transportation conditions. This study is not a plan and will not result in a decision or project without further planning and community engagement. However, this study will provide KEFJ and the National Park Service (NPS) Alaska Region (AKR) with information and analysis to better understand the current state of transportation access to the Exit Glacier Area and the feasibility of potential enhanced access. NPS and KEFJ are not considering an NPS-owned or operated transit system to provide park access, and are instead interested in identifying options for the park to support business opportunities for private entities. The specific goals of this study are to understand current conditions and demand for transit service to the Exit Glacier Area; identify short-term strategies to improve transportation access for visitors; and consider visitation and transportation trends and anticipate future needs

    Carbohydrate antigens in nipple aspirate fluid predict the presence of atypia and cancer in women requiring diagnostic breast biopsy

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    <p>Abstract</p> <p>Background</p> <p>The goal of this prospective study was to determine (a) concentrations of the carbohydrate biomarkers Thomsen Friedenreich (TF) antigen and its precursor, Tn antigen, in nipple discharge (ND) collected from women requiring biopsy because of a suspicious breast lesion; and (b) if concentration levels predicted pathologic diagnosis.</p> <p>Methods</p> <p>Adult women requiring biopsy to exclude breast cancer were enrolled and ND obtained. The samples from 124 women were analyzed using an anti-TF and anti-Tn monoclonal antibodies in direct immunoassay.</p> <p>Results</p> <p>The highest median concentration in ND for TF and Tn was in women with ductal carcinoma <it>in situ </it>(DCIS). TF was higher in women with 1) cancer (DCIS or invasive) vs. either no cancer (atypia or benign pathology, p = .048), or benign pathology (p = .018); and 2) abnormal (atypia or cancer) versus benign pathology (p = .016); and was more predictive of atypia or cancer in post- compared to premenopausal women. Tn was not predictive of disease. High TF concentration and age were independent predictors of disease, correctly classifying either cancer or abnormal vs. benign pathology 83% of the time in postmenopausal women.</p> <p>Conclusions</p> <p>TF concentrations in ND were higher in women with precancer and cancer compared to women with benign disease, and TF was an independent predictor of breast atypia and cancer. TF may prove useful in early breast cancer detection.</p
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