Influence of pitch size and age category on the physical and physiological responses of young football players during small-sided games using GPS devices

ABSTRACT

This study aimed to compare the physical and physiological responses of young football players of different categories during small-sided games (SSGs) played on different pitch sizes. Forty-eight (24 U-13 and 24 U-14) athletes played a 3 vs. 3 + 1 SSG in two experimental conditions: regular (36 × 27 m) and large pitch sizes (40 × 29 m). The total distance covered, the distances covered at different speed zones (0 to 6.9 km/h, 6.9 to 14.3, and 14.3 to 21.4), maximum heart rate, and mean heart rate were recorded. The results showed that older athletes covered larger distances during SSGs (p = 0.001; d = 0.937; large effect) and lower distances at the lowest (0–6.9 km/h) speed zone (p = 0.001; d = 0.657; moderate-to-large effect). Neither the physical nor physiological variables (except for distance covered between 14.3 and 21.4 km/h) differed between pitch sizes. This result indicates that pitch size may not impact the physical or physiological responses of U-13 and U-14 players during SSGs, but differences between categories were found. In conclusion, the development of tactical skills may be desirable to better explore the available space in the same age categories.     

The gait profile score characterises walking performance impairments in young stroke survivors

BackgroundThe Gait Profile Score (GPS) provides a composite measure of the quality of joint movement during walking, but the relationship between this measure and metabolic cost, temporal (e.g. walking speed) and spatial (e.g. stride length) parameters in stroke survivors has not been reported.Research Question: The aims of this study were to compare the GPS (paretic, non-paretic, and overall score) of young stroke survivors to the healthy able-bodied control and determine the relationship between the GPS and metabolic cost, temporal (walking speed, stance time asymmetry) and spatial (stride length, stride width, step length asymmetry) parameters in young stroke survivors to understand whether the quality of walking affects walking performance in stroke survivors.MethodsThirty-nine young stroke survivors aged between 18 and 65years and 15 healthy age-matched able-bodied controls were recruited from six hospital sites in Wales, UK. Joint range of motion at the pelvis, hip, knee and ankle, and temporal and spatial parameters were measured during walking on level ground at self-selected speed with calculation of the Gait Variable Score and then the GPS.ResultsGPS for the paretic leg (9.40° (8.60–10.21) p < 0.001), non-paretic leg (11.42° (10.20–12.63) p < 0.001) and overall score (11.18° (10.26–12.09) p < 0.001)) for stroke survivors were significantly higher than the control (4.25° (3.40–5.10), 5.92° (5.11 (6.73)). All parameters with the exception of step length symmetry ratio correlated moderate to highly with the GPS for the paretic, non-paretic, and/or overall score (ρ = <−0.732 (p < 0.001)).SignificanceThe quality of joint movement during walking measured via the GPS is directly related to the speed and efficiency of walking, temporal (stance time symmetry) and spatial (stride length, stride width) parameters in young stroke survivors.     

Merging self-reported with technically sensed data for tracking mobility behavior in a naturalistic intervention study. Insights from the GISMO study

Sound exposure data are central for any intervention study. In the case of utilitarian mobility, where studies cannot be conducted in controlled environments, exposure data are commonly self-reported. For short-term intervention studies, wearable devices with location sensors are increasingly employed. We aimed to combine self-reported and technically sensed mobility data, in order to provide more accurate and reliable exposure data for GISMO, a long-term intervention study. Through spatio-temporal data matching procedures, we are able to determine the amount of mobility for all modes at the best possible accuracy level. Self-reported data deviate ±10% from the corrected reference. Derived modal split statistics prove high compliance to the respective recommendations for the control group (CG) and the two intervention groups (IG-PT, IG-C). About 73.7% of total mileage was travelled by car in CG. This share was 10.3% (IG-PT) and 9.7% (IG-C), respectively, in the intervention groups. Commuting distances were comparable in CG and IG, but annual mean travel times differ between  = 8,458 min (σ = 6,427 min) for IG-PT,  = 8,444 min (σ = 5,961 min) for IG-C, and  = 5,223 min (σ = 5,463 min) for CG. Seasonal variabilities of modal split statistics were observable. However, in IG-PT and IG-C no shift toward the car occurred during winter months. Although no perfect single-method solution for acquiring exposure data in mobility-related, naturalistic intervention studies exists, we achieved substantially improved results by combining two data sources, based on spatio-temporal matching procedures.     

High levels of soluble GPR56/ADGRG1 are associated with positive rheumatoid factor and elevated tumor necrosis factor in patients with rheumatoid arthritis

Background

GPR56/ADGRG1 is a member of the adhesion-class G protein-coupled receptor (aGPCR) family important in brain development, oncogenesis and tumor metastasis. Like other aGPCRs, GPR56 is cleaved at the GPCR proteolysis site (GPS) motif into an N-terminal fragment (NTF) and a C-terminal fragment (CTF). Existence of soluble GPR56 (sGPR56) has been shown in vitro, however the underlying mechanism and its pathophysiologic role remains undetermined.

Visualizing changes in physical activity behavioral patterns after redesigning urban infrastructure

The aim of this study was to explore effects of a major urban reconstruction on physical activity (PA) behavior by comparing PA intensity hotspots before and after the tunneling of a highway with a new infrastructure prioritized for walking and cycling. In total, 126 individuals participated before and after the tunneling. GPS loggers and accelerometers were used to assess location and PA levels. A geographic information system (GIS) was used to perform optimized hotspot analyses on PA data, both on transport and stationary data points. The results showed several changes in PA hotspots on trip data, even if total PA levels did not change. At follow-up, PA intensity hotspots were more connected, with the new infrastructure as a central connection. This was true for higher and lower educated individuals. Therefore, if changes in the built environment do not result in changes on population-level outcomes, this does not imply that they have no impact on behavior.     

Household-Level Spatiotemporal Patterns of Incidence of Cholera,Haiti, 2011

A cholera outbreak began in Haiti during October, 2010. Spatiotemporal patterns of household-level cholera in Ouest Department showed that the initial clusters tended to follow major roadways; subsequent clusters occurred further inland. Our data highlight transmission pathway complexities and the need for case and household-level analysis to understand disease spread and optimize interventions.     

基于子空间技术的常规多波束形成抗干扰算法

卫星导航系统（GPS）的很多抗干扰技术是以卫星信号来向估计为基础的,当估计卫星信号来向有困难时,这些算法将失效。提出了一种基于子空间投影的常规多波束抗干扰算法。该方法先进行子空间投影抑制干扰,然后在固定方向上采用常规波束形成方法（CBF）形成多个主波束,最后对每个波束得到的无干扰数据进行捕获及定位解算等。该方法的特点是不需要知道卫星信号来向,并且在信号方向上具有一定的天线增益,适用于天线阵元数目少、估计卫星信号来向有困难的应用场景。