2,080 research outputs found

    A comparison of frontal plane projection angle across landing tasks in female gymnasts

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    The aim of this study was to compare FPPA between three landing tasks and determine the reliability of FPPA in 15 competitive female gymnasts (age 13.5 ± 2.07 years). Reliability of FPPA was highest in the drop landing task, with no learning effect present. The backaway task showed the greatest FFPA (right: 26.75 ± 9.57°; left: 19.67 ± 9.03°), which was greater than the drop landing task (right: 19.07 ± 7.42°; left: 12.18 ± 4.83°). Individuals involved in training young female gymnasts are encouraged to screen for injury risk using FPPA during the drop landing task

    The relationship between 2D knee valgus angle during single leg squat, single leg land and drop jump screening tests

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    Context: Injuries to the anterior cruciate ligament (ACL) and patellofemoral joint (PFJ) are a significant problem in female athletes. A number of screening tasks have been used in the literature to identify those at greatest risk of injury. To date, no study has examined the relationship in 2-dimensional (2D) knee valgus between common screening tasks to determine whether individuals exhibit similar movement patterns across tasks. Objective: To establish whether frontal-plane projection angle (FPPA) during the single-leg squat (SLS), single-leg land (SLL), and drop jump (DJ) are related. Design: Cross-sectional study. Setting: University laboratory. Participants: 52 national-league female football players and 36 national-league female basketball players. Main Outcome Measures: 2D FPPA during the SLS, SLL, and DJ screening tasks. Results: Significant correlations were found between tasks. FPPA in the SLS was significantly correlated with SLL (r = .52) and DJ (r = .30), whereas FPPA in the SLL was also significantly correlated to DJ (r = .33). FPPA was significantly greater in the SLS than in the SLL (P < .001) and DJ (P < .001) and in the SLL than in the DJ (P < .001). Conclusion: The results showed that 2D FPPA is correlated across the SLS, SLL, and DJ tasks. However, significantly greater FPPA values in the unilateral tasks suggest that the DJ may not identify risk of injury in sports where primary injury mechanisms are during unilateral loading tasks. Therefore, it is recommended that both unilateral and bilateral tasks be included when screening for ACL and PFJ injury risk

    Effectiveness of Hindman's theorem for bounded sums

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    We consider the strength and effective content of restricted versions of Hindman's Theorem in which the number of colors is specified and the length of the sums has a specified finite bound. Let HTkn\mathsf{HT}^{\leq n}_k denote the assertion that for each kk-coloring cc of N\mathbb{N} there is an infinite set XNX \subseteq \mathbb{N} such that all sums xFx\sum_{x \in F} x for FXF \subseteq X and 0<Fn0 < |F| \leq n have the same color. We prove that there is a computable 22-coloring cc of N\mathbb{N} such that there is no infinite computable set XX such that all nonempty sums of at most 22 elements of XX have the same color. It follows that HT22\mathsf{HT}^{\leq 2}_2 is not provable in RCA0\mathsf{RCA}_0 and in fact we show that it implies SRT22\mathsf{SRT}^2_2 in RCA0\mathsf{RCA}_0. We also show that there is a computable instance of HT33\mathsf{HT}^{\leq 3}_3 with all solutions computing 00'. The proof of this result shows that HT33\mathsf{HT}^{\leq 3}_3 implies ACA0\mathsf{ACA}_0 in RCA0\mathsf{RCA}_0

    The effects of a four week jump-training program on frontal plane projection angle in female gymnasts

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    Objectives: To investigate the effects of a four week jump training program on frontal plane projection angle (FPPA) in young female gymnasts. Design: Intervention study, consisting of a four week jump training program performed for 15 minutes as part of a warm-up, three days per week for four weeks. Setting: Gymnastics training center. Participants: Fourteen youth female gymnasts (age: 13.5 ± 2.14 years, height: 1.54 ± 0.11 m, body mass: 46.23 ± 7.68 kg). Main Outcome Measures: Change in FPPA during a 30 cm drop landing and tuck back somersault. Results: Large and significant decreases (p &lt; 0.001) in FPPA of 6.8° (39%) and 8.4° (37%) during the drop landing and tuck back somersault, respectively. Conclusion: The jump training program was successful in improving FPPA in female gymnasts and is advised to be implemented into the warm-ups and training programs of competitive female gymnasts to improve FPPA and therefore reduce the risk factors associated with knee injuries

    Dynamics of genotype-specific HPV clearance and reinfection in rural Ghana may compromise HPV screening approaches

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    Persistent Human Papillomavirus (HPV) infection is a prerequisite for cervical cancer development. Few studies investigated clearance of high-risk HPV in low-and-middle-income countries. Our study investigated HPV clearance and persistence over four years in women from North Tongu District, Ghana. In 2010/2011, cervical swabs of 500 patients were collected and HPV genotyped (nested multiplex PCR) in Accra, Ghana. In 2014, 104 women who previously tested positive for high-risk HPV and remained untreated were re-tested for HPV. Cytobrush samples were genotyped (GP5+/6+ PCR & Luminex-MPG readout) in Berlin, Germany. Positively tested patients underwent colposcopy and treatment if indicated. Of 104 women, who tested high-risk HPV+ in 2010/2011, seven (6,7%; 95%CI: 2.7-13.4%) had ≥1 persistent high-risk-infection after ~4 years (mean age 39 years). Ninety-seven (93,3%; 95%CI: 86.6-97.3%) had cleared the original infection, while 22 (21.2%; 95%CI: 13.8-30.3%) had acquired new high-risk infections with other genotypes. Persistent types found were HPV 16, 18, 35, 39, 51, 52, 58, and 68. Among those patients, one case of CIN2 (HPV 68) and one micro-invasive cervical cancer (HPV 16) were detected. This longitudinal observational data suggest that single HPV screening rounds may lead to over-referral. Including type-specific HPV re-testing or additional triage methods could help reduce follow-up rates

    Winter rations for feeder calves

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    Status of the TRIUMF PIENU Experiment

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    The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio R=Γ(π+e+νe(γ))/Γ(π+μ+νμ(γ))R={\Gamma}({\pi}^+{\rightarrow}e^+{\nu}_e({\gamma}))/{\Gamma}({\pi}^+{\rightarrow}{\mu}^+{\nu}_{\mu}({\gamma})) with precision <0.1<0.1% to provide a sensitive test of electron-muon universality in weak interactions. The current status of the PIENU experiment is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure

    Improved Search for Heavy Neutrinos in the Decay πeν\pi\rightarrow e\nu

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    A search for massive neutrinos has been made in the decay πe+ν\pi\rightarrow e^+ \nu. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (πe+νh\pi\rightarrow e^+ \nu_h). Upper limits (90 \% C.L.) on the neutrino mixing matrix element Uei2|U_{ei}|^2 in the neutrino mass region 60--135 MeV/c2c^2 were set, which are %representing an order of magnitude improvement over previous results

    DE 1 RIMS operational characteristics

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    The Retarding Ion Mass Spectrometer (RIMS) on the Dynamics Explorer 1 spacecraft observes both the thermal and superthermal (50 eV) ions of the ionosphere and inner magnetosphere. It is capable of measuring the detailed species distribution function of these ions in many cases. It was equipped with an integral electrometer to permit in-flight calibration of the detector sensitivities and variations thereof. A guide to understanding the RIMS data set is given. The reduction process from count rates to physical quantities is discussed in some detail. The procedure used to establish in-flight calibration is described, and results of a comparison with densities from plasma wave measurements are provided. Finally, a discussion is provided of various anomalies in the data set, including changes of channeltron efficiency with time, spin modulation of the axial sensor heads, apparent potential differences between the sensor heads, and failures of the radial head retarding potential sweep and of the -Z axial head aperture plane bias. Studies of the RIMS data set should be conducted only with a thorough awareness of the material presented here, or in collaboration with one of the scientists actively involved with RIMS data analysis
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