312 research outputs found

    Sled Pull Training Protocol Does Not Improve Peak Force and Increases Asymmetry in Collegiate Soccer Players

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    Speed and acceleration are trainable components that are critical determinants of success in team sports, particularly soccer. Lower extremity strength is one of many factors that determine the maximal force output and velocity of individuals, which is critical to success in sport. PURPOSE: To determine the effects of a 12-week sled pull training intervention on isometric leg strength and asymmetry. METHODS: Participants from Division 1 collegiate men (20 ± 1.5yrs, 168.28 ± 51.17cm, 73.44 ± 23.46kg) and women’s soccer (19.58 ± 1.02yrs, 167.07 ± 3.81cm, 62.46 ± 8.41kg) team performed pre-training isometric thigh pulls on force plates measuring peak force generation, bilaterally. Participants then performed a 12-week training program consisting of sled pulls performed at 80% of bodyweight, three days a week for 6 weeks followed by a 6-week maintenance phase of sled pulls conducted at 50% of bodyweight and post-intervention testing. RESULTS: The pre-training average relative peak force of the left and right legs of male participants were 14.46 ± 1.61N/kg and 14.42 ± 1.33N/kg, respectively, and 11.76 ± 0.69N/kg and 11.67 ± 1.08N/kg, respectively, of female participants. Sled pull training trended (p=0.07) to increase relative peak force in the right leg in both men (15.11 ± 2.14N/kg) and women (12.27 ± 1.31N/kg). However, training trended (p=0.09) to decrease peak left leg force in both men (13.60±2.32N/kg), but less so in women (11.19 ± 1.77N/kg). This leg specific training effect increased (pCONCLUSION: Sled pull training increased asymmetry in both men and women. The increased asymmetry could be attributed to a consistent decline in unilateral force production in the left leg in men. However, there was no consistent pattern to explain the increased asymmetry in women

    Sled-Pull Training Protocol Increases Critical Speed in Female Collegiate Soccer Players

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    Critical speed (CS) is the speed one can sustain while maintaining blood lactate, phosphocreatine, and oxygen uptake levels. “Distance capacity beyond CS” (D’) is the reserve an athlete can draw from to run faster than their CS. By increasing CS and D’, athletes can sustain a faster threshold pace (CS) and have a greater sprint capacity (D’). Unlike distance traveled and speed, which do not reflect the metabolic strain of an exercise, CS and D’ assess the relative intensity of an activity to provide individualized inter- and intra-competition insight. PURPOSE: This investigation evaluated CS and D’ among men and women Division I collegiate soccer players for the first time and assessed the efficacy of a 12-week sled-pulling program intended to improve their CS profiles. METHODS: Using a 3-minute all-out 25-meter shuttle run, the speed of the first 150s (S’150), CS, and D’ of 23 men (20.22 ± 1.53 years, 168.28 ± 51.17 cm, 73.44 ± 23.46 kg) and 17 women (19.58 ± 1.02 years, 167.07 ± 3.81 cm, 62.46 ± 8.41 kg) was assessed before and after the training protocol. Video analysis was used to track displacement over time. RESULTS: The training program increased the S’150 of men by 3.58% (3.66 ±0.19 vs 3.77 ± 0.17 m/s, pCONCLUSION: Sled-pull training improved the CS profile of both men and women. Additional research is necessary to determine how improvements in S’150 and CS translate to better performance in competition

    3D Assessment of Nasopharyngeal and Craniofacial Phenotypes in Ts65Dn Down Syndrome Mice Treated with a Dyrk1a Inhibitor

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    Background: Down syndrome (DS) originates from having three copies of chromosome 21 (i.e. Trisomy 21). DS is associated with many detrimental phenotypes including intellectual disabilities, heart defects, abnormal craniofacial development, and obstructive sleep apnea, which develops from restricted nasopharyngeal airways and an underdeveloped mandible. Ts65Dn mice are trisomic for about half of the orthologs on human chromosome 21 and display many phenotypes associated with DS including craniofacial abnormalities. Dyrk1a is found in three copies in Ts65Dn mice and individuals with DS, and thought to be a root cause of the craniofacial phenotypes. Epigallocatechin 3-gallate (EGCG) is a green tea polyphenol and inhibitor of Dyrk1a activity. Purpose: We hypothesize that decreased Dyrk1a activity in Ts65Dn mice will ameliorate craniofacial dysmorphology. Methods: To test our hypothesis we compared Ts65Dn mice with two or three copies of Dyrk1a and compared Ts65Dn mice with and without prenatal EGCG treatment. EGCG treated mothers were fed 200mg/kg EGCG on gestational day 7. Six week old mice were sacrificed and their heads imaged using micro-computed tomography (ÎĽCT). From ÎĽCT images, we measured nasopharyngeal airway volume and anatomical landmarks (n = 54) from the facial skeleton, cranial vault, cranial base, and mandible. Mean nasopharyngeal airway volumes were graphically compared, and a landmark-based multivariate geometric morphometric approach known as Euclidean Distance Matrix Analysis (EDMA) was carried out to assess local differences in craniofacial morphology between trisomic mouse samples. Results: Our preliminary results indicate that EGCG treatment and reduced Dyrk1a copy number increases mean nasopharyngeal airway volume in Ts65Dn mice. Craniofacial morphometric differences were found among all samples. EGCG treatment increased portions of the mandible and decreased portions of the cranial vault and cranial base. Conclusion: Preliminary analyses suggest that both EGCG treatment and reduced Dyrk1a copy number affect craniofacial morphology.Three Dimensional Imaging of the Craniofacial Complex Center (3D ICCC)--IUPUI Signature Center Initiative

    Sled-pull Training Improves Maximal Horizontal Velocity in Collegiate Male and Female Soccer Players

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    The force velocity profile (FvP), which details the capacity to sprint and accelerate, is a determinant of success in soccer. To date, no data exist that details the FvP of male and female collegiate Division I soccer players. Further, there is limited insight on how training interventions may modify the FvP of either males or females. PURPOSE: The aim of this investigation was to compare FvP between collegiate male and female athletes and assess the efficacy of a 12-week sled pull training intervention. METHODS: 17 male (20.17 ± 1.38 yrs) and 12 female (19.75 ± 1.05 yrs) soccer players participated in a 12-week sled pull training intervention. FvP was measured prior, during, and after training using a 30m sprint to assess maximal horizontal force (F0), maximal horizontal speed (V0), and maximal power output (Pmax). RESULTS: The intervention improved 30m sprint times of men by 11.86% (pre: 4.35 ± 0.17s, post: 4.27 ± 0.17, p0 in both men (pre: 7.98 ± 0.36 m/s, post: 8.09 ± 0.35 m/s, p0 or Pmax. CONCLUSION: This is the first study to detail FvP in both male and female collegiate soccer players. A 12-week sled pull training intervention improves 30m sprint times and V0 in both male and female collegiate athletes, but does not improve F0 and Pmax. Thus, the sled pull intervention should be modified or paired with other training that specifically targets force and power development

    Application of Serological Tools and Spatial Analysis to Investigate Malaria Transmission Dynamics in Highland Areas of Southwest Uganda.

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    Serological markers, combined with spatial analysis, offer a comparatively more sensitive means by which to measure and detect foci of malaria transmission in highland areas than traditional malariometric indicators. Plasmodium falciparum parasite prevalence, seroprevalence, and seroconversion rate to P. falciparum merozoite surface protein-119 (MSP-119) were measured in a cross-sectional survey to determine differences in transmission between altitudinal strata. Clusters of P. falciparum parasite prevalence and high antibody responses to MSP-119 were detected and compared. Results show that P. falciparum prevalence and seroprevalence generally decreased with increasing altitude. However, transmission was heterogeneous with hotspots of prevalence and/or seroprevalence detected in both highland and highland fringe altitudes, including a serological hotspot at 2,200 m. Results demonstrate that seroprevalence can be used as an additional tool to identify hotspots of malaria transmission that might be difficult to detect using traditional cross-sectional parasite surveys or through vector studies. Our study findings identify ways in which malaria prevention and control can be more effectively targeted in highland or low transmission areas via serological measures. These tools will become increasingly important for countries with an elimination agenda and/or where malaria transmission is becoming patchy and focal, but receptivity to malaria transmission remains high

    Eccentric and concentric muscle performance following 7 days of simulated weightlessness

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    Changes in skeletal muscle strength occur in response to chronic disuse or insufficient functional loading. The purpose of this study was to examine changes in muscle performance of the lower extremity and torso prior to and immediately after 7 days of simulated weightlessness (horizontal bed rest). A Biodex was used to determine concentric and eccentric peak torque and angle at peak torque for the back, abdomen, quadriceps, hamstring, soleus, and tibialis anterior. A reference angle of 0 degrees was set at full extension. Data were analyzed by ANOVA

    Independent origin of plasmodium falciparum antifolate super-resistance, Uganda, Tanzania, and Ethiopia.

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    Super-resistant Plasmodium falciparum threatens the effectiveness of sulfadoxine-pyrimethamine in intermittent preventive treatment for malaria during pregnancy. It is characterized by the A581G Pfdhps mutation on a background of the double-mutant Pfdhps and the triple-mutant Pfdhfr. Using samples collected during 2004-2008, we investigated the evolutionary origin of the A581G mutation by characterizing microsatellite diversity flanking Pfdhps triple-mutant (437G+540E+581G) alleles from 3 locations in eastern Africa and comparing it with double-mutant (437G+540E) alleles from the same area. In Ethiopia, both alleles derived from 1 lineage that was distinct from those in Uganda and Tanzania. Uganda and Tanzania triple mutants derived from the previously characterized southeastern Africa double-mutant lineage. The A581G mutation has occurred multiple times on local Pfdhps double-mutant backgrounds; however, a novel microsatellite allele incorporated into the Tanzania lineage since 2004 illustrates the local expansion of emergent triple-mutant lineages

    World Antimalarial Resistance Network (WARN) III: Molecular markers for drug resistant malaria

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    Molecular markers for drug resistant malaria represent public health tools of great but mostly unrealized potential value. A key reason for the failure of molecular resistance markers to live up to their potential is that data on the their prevalence is scattered in disparate databases with no linkage to the clinical, in vitro and pharmacokinetic data that are needed to relate the genetic data to relevant phenotypes. The ongoing replacement of older monotherapies for malaria by new, more effective combination therapies presents an opportunity to create an open access database that brings together standardized data on molecular markers of drug resistant malaria from around the world. This paper presents a rationale for creating a global database of molecular markers for drug resistant malaria and for linking it to similar databases containing results from clinical trials of drug efficacy, in vitro studies of drug susceptibility, and pharmacokinetic studies of antimalarial drugs, in a World Antimalarial Resistance Network (WARN). This database will be a global resource, guiding the selection of first line drugs for treating uncomplicated malaria, for preventing malaria in travelers and for intermittent preventive treatment of malaria in pregnant women, infants and other vulnerable groups. Perhaps most important, a global database for molecular markers of drug resistant malaria will accelerate the identification and validation of markers for resistance to artemisinin-based combination therapies and, thereby, potentially prolong the useful therapeutic lives of these important new drugs

    High-resolution observations of low-luminosity gigahertz-peaked spectrum and compact steep-spectrum sources

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    © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. We present very long baseline interferometry observations of a faint and low-luminosity (L 1.4 GHz < 10 27 W Hz -1 ) gigahertz-peaked spectrum (GPS) and compact steep-spectrum (CSS) sample. We select eight sources from deep radio observations that have radio spectra characteristic of a GPS or CSS source and an angular size of Φ <~ 2 arcsec, and detect six of them with the Australian Long Baseline Array. We determine their linear sizes, and model their radio spectra using synchrotron self-absorption (SSA) and free-free absorption (FFA) models. We derive statistical model ages, based on a fitted scaling relation, and spectral ages, based on the radio spectrum, which are generally consistent with the hypothesis that GPS and CSS sources are young and evolving. We resolve the morphology of one CSS source with a radio luminosity of 10 2 5WHz -1 , and find what appear to be two hotspots spanning 1.7 kpc. We find that our sources follow the turnover-linear size relation, and that both homogeneous SSA and an inhomogeneous FFA model can account for the spectra with observable turnovers. All but one of the FFA models do not require a spectral break to account for the radio spectrum, while all but one of the alternative SSA and power-law models do require a spectral break to account for the radio spectrum. We conclude that our low-luminosity sample is similar to brighter samples in terms of their spectral shape, turnover frequencies, linear sizes, and ages, but cannot test for a difference in morphology

    Translational pharmacology of an inhaled small molecule αvβ6 integrin inhibitor for idiopathic pulmonary fibrosis

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    The αvβ6 integrin plays a key role in the activation of transforming growth factor-β (TGFβ), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule αvβ6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and diseaserelated end points. Here we report, GSK3008348 binds to αvβ6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFβ signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the αvβ6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages αvβ6, induces prolonged inhibition of TGFβ signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy
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