Search

Quarry fines are secondary materials that can be reused for road construction, commonly after improving their properties through stabilising. To better understand and characterise these recycled materials, we created an image-based, two-dimensional representation of the particles that compose the material. This computational representation enables (1) the quantification of the (area-based) gradation from images, (2) a detailed particle-by-particle characterisation and (3) potentially, random rearrangement of the particles into reconstructed specimens for further computational analyses. The images of cement-stabilised quarry fines were obtained using a scanning electron microscope. The particles were isolated and characterised using image processes and a computational approach (MATLAB code). The techniques and code presented herein can be applied as well to other granular-based materials. The MATLAB code and associated files are available as an open resource in GitHub (). [ABSTRACT FROM AUTHOR]

This study aimed to explore the match-physical response of international-level footballers with cerebral palsy (CP) according to contextual factors such as team ranking, the quality level of opposition, and match outcome. Eighty-two male outfield footballers with CP from top-ranked teams (n = 26) and bottom-ranked teams (n = 56) took part in this study. The match-player response was recorded using global positioning devices considering the total distance, distance covered at different velocities and number of short-term actions. Players from top-ranked teams covered more distance at low intensities compared to players from bottom-ranked teams (p < 0.05; 0.45 < ES < 0.49). Higher sprint distance, moderate and high accelerations/decelerations were found in players from top-ranked teams playing against teams of similar levels (p < 0.05; 0.73g< 0.86). When players from bottom-ranked teams played against teams of equivalent rank, more physical requirements were presented in total distance, running from medium to sprint intensities, and the number of short-term actions (p < 0.0.05; −0.55S < −0.89). Players from the top-ranking teams presented greater sprint demands in losing matches (p<0.05; dg=-1.01). Considering the bottom-ranking opposition, players presented more running demands in matches with losing results in moderate running, sprinting, and moderate-to-high deceleration (p < 0.05; −0.61 < dg < −0.64). The match-physical response of players with CP varies according to the contextual factors studied. The results provide advice for coaches and classifiers to understand more comprehensively the competing demands in CP football. This knowledge could help practitioners to prepare competition matches and planning training load or post-match recovery strategies, but also for the observation assessments of the classification process in this team para-sport. [ABSTRACT FROM AUTHOR]

This study aimed to analyse the effects of a 16-week jump training program on the physical performance and lower extremities injury profile in semi-professional male soccer players. Participants were randomly assigned to the control group (CG; n = 13; age = 21.7 ± 3.6 years) or the experimental group (EG; n = 10; age = 22.3 ± 3.5 years). Countermovement jump (CMJ) height (cm), 30 m linear sprint time (s) with split times at 10 m and 20 m distances, and change of direction speed (CODS; 10 + 10 m with 90° turn) time (s) with turns using the dominant or non-dominant leg, were assessed before and after the intervention. Lower extremity injuries sustained throughout the intervention period were collected. Significant within-group improvements were found in EG in CMJ (p = 0.01; effect size [ES] = 1.03; large). Additionally, between-group difference after intervention was found in CMJ (F = 4.42; p = 0.013) in favour of EG. Injury burden was 194.86 (CG) vs 71.37 (EG) days of absence/1,000 h (RR = 2.73; 95% CI 2.10–3.54; p < 0.001). No other significant within-group or between-group differences were found. In conclusion, compared to regular soccer training, jump training was effective to improve jumping ability and burden in soccer players. [ABSTRACT FROM AUTHOR]

Surface hot-in place recycling of asphalt mixtures has been conducted on Finnish roads for several years. The procedure is performed either in full-lane('remix') or shorter widths ('rut-remix'). In a 2020-2021 project, different mixture types were subjected to both kinds of recycling; reference mixtures, and mixtures modified with aramid fibres, FEP elastomer pellets, polymer, Storelastic rubber additive, recycled asphalt shingles, steel slag, and soft bitumen. This paper (Part II) presents the results of an extensive laboratory test plan at the bitumen scale. Asphalt mixture cores were recovered from four roads, and the bitumen was extracted fortesting. Various tests were performed on the bitumens in original state (aged, before recycling) and after recycling (remix or rut-remix), including FT-IR, DSR, MSCR, as well as bitumen content, penetration, and softening point. The master curves were constructed for all bitumens. Gradations are also presented herein. The effect of remix/rut-remix is evaluated via changes in all measured properties (including Glover-Rowe) before and after recycling, over a wide range of temperatures. The results complement the mixture-scale data and provide a comprehensive database of bitumen performance for an extended group of materials. Data appendices are accessible from the link at the bottom of the page. [ABSTRACT FROM AUTHOR]

Surface hot-in place recycling of asphalt mixtures has been conducted on Finnish roads for several years. The procedure is performed either in full-lane ('remix') or shorter widths ('rut-remix'). In a 2020–2021 project, different mixture types were subjected to both kinds of recycling; reference mixtures, and mixtures modified with aramid fibres, FEP elastomer pellets, polymer, Storelastic rubber additive, recycled asphalt shingles, steel slag, and soft bitumen. This paper (Part I) presents the results of an extensive laboratory test plan at the mixture scale. Asphalt mixture cores were recovered from four roads. Various tests were performed on the mixtures in original state (aged, before recycling) and after recycling (remix or rut-remix), including strength (ITSR), stiffness, Prall abrasion, creep permanent deformation, as well as bulk, air voids, and thickness measurements. The effect of remix/rut-remix is assessed using scores calculated from mixture-scale test results. The results show that remix and rut-remix are highly heterogeneous processes, affecting every material differently and sometimes erratically. Adequate air void contents and evenness in compaction are critical for good performance. The results provide a reference performance database for an extended group of materials. Data appendices are accessible from the link at the bottom of the page. [ABSTRACT FROM AUTHOR]

There is a lack of evidence regarding the match demands encountered in elite Ultimate Frisbee (UF) overall and dependent upon opponent ranking. These data may be useful to elite UF coaches to implement optimal training loads and recovery strategies. Therefore, this study quantified the physical demands of elite UF match-play and analysed differences in demands according to opponent ranking. Twelve UF players from the same national team participated in the study. An observational design was used to compare the physical demands encountered by players between opponents carrying different rankings (1st, 3rd, 4th, and 5th) during four official matches in a 5-team competition. No significant differences (p > 0.05) in sprinting and repeated-sprinting activity were evident across UF matches between opponents. In contrast, a higher (moderate-large) quantity and greater intensities of body impacts were observed in UF matches played against higher-ranked (1st) compared to lower-ranked teams (3rd, 4th, and 5th). Additionally, greater (moderate-large) PL and metabolic power were observed in matches played against higher-ranked (1st) compared to lower-ranked teams (3rd and 4th). These findings suggest coaches may need to reduce the training loads in the next days after the matches played against higher-ranked opponents compared to when facing lower-ranked opponents. [ABSTRACT FROM AUTHOR]

The main objective of this study was to compare the physical response of para-footballers with cerebral palsy (CP) in official international football matches played at moderate altitude and sea level locations. Eighty-seven international CP footballers participated in this study. We divided participants according to the place of the international competition [sea level group (SLG) and moderate altitude group (MAG)], sport classes (i.e., FT1, FT2, and FT3), and match playing time (i.e., <20 min, 20‒40 min, and >40 min). We recorded the physical response using global position system devices during matches. This study showed that MAG described a lower physical response than SLG on total distance, distance covered at different intensities, and the number of accelerations and decelerations. FT2 and FT3 presented a similar pattern, where we found significant differences for total distance, distance covered at lower and high intensities and moderate accelerations, and decelerations. Considering the playing time during altitude matches, the 20‒40 min and >40 min groups obtained more marked differences in the physical response variables. Para-footballers with CP who competed under altitude conditions showed a lower physical response during football matches, suggesting the implementation of specific preparation and training strategies to face the demanding environmental conditions. [ABSTRACT FROM AUTHOR]

The aims of the current systematic review were to evaluate the current literature surrounding the chronic effect of flywheel training on the physical capacities of soccer players, and to identify areas for future research to establish guidelines for its use. Studies were identified following a search of electronic databases (PubMed and SPORTDiscus) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA). Eleven studies met the inclusion criteria and were included. The methodological quality of the included studies ranged between 10 and 18 with an average score of 15 points using the PEDro scale. The training duration ranged from 6 weeks to 27 weeks, with volume ranging from 1 to 6 sets and 6 to 10 repetitions, and frequency from 1 to 2 times a week. This systematic review reported that a diverse range of flywheel training interventions can effectively improve strength, power, jump, and changes of direction in male soccer players of varying levels. Flywheel training interventions improve the physical capacities of soccer players of varying levels. Nonetheless, the current literature suggests contrasting evidence regarding flywheel training induced changes in sprint speed and acceleration capacity of soccer players. [ABSTRACT FROM AUTHOR]

Stabilised quarry fines have been explored as sustainable pavement construction materials. This study investigates the viability of such materials for applications in pavement structures, contributing to current knowledge on mechanical performance from the perspective of mineralogy, microstructure, and chemical composition of the material. This study uses fly ash-based material as stabiliser, promoting circular economy considering the availability of fly ash worldwide by 2030. Laboratory tests were performed including unconfined compressive strength (UCS), mineralogical analysis, and microstructure investigations by scanning electronic microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). Using different binders, Calcium was found to be the element with most variability in mass, and the UCS increased proportionally as the ratio of CaO/SiO2 or CaO/(SiO2+Al2O2) increased. As curing time accumulates to 28 days, more cementitious reaction products were generated and observed, and the void to solid ratio reduced in some samples, possibly leading to improvements in the UCS. [ABSTRACT FROM AUTHOR]

This study investigated the effects of a weekly flywheel resistance training session over a 10-week period on U16 soccer players' physical performance with special attention to change of direction ability (e.g., deficit [CODdef]). Twenty elite young soccer players were assigned to an experimental (EG, n = 10) or control (CG, n = 10) group. Unilateral countermovement jumps with dominant (CMJd) and non-dominant (CMJnd) leg, 10, 20, and 30-m linear sprint test and change of direction sprint test in 5 + 5 (COD10) and 10 + 10 m (COD20) were performed before and after flywheel training period. Significant within-group differences were found in CG in COD10 (p = 0.01; effect size [ES] = large) and CODdef10 (p = 0.03; ES = small) with dominant leg, while differences in EG were observed in CMJ (p = 0.001–0.01; ES = moderate-large) and in all COD and CODdef variables (p = 0.001–0.04; ES = large). Between-groups analysis revealed differences in favour of the EG in CMJ (p = 0.03–0.05) and COD and CODdef variables (p = 0.001–0.05). These findings suggest a weekly flywheel training session is suitable for improving jumping and COD abilities in U16 elite soccer players in season. [ABSTRACT FROM AUTHOR]

Impaired coordination is a characteristic feature in cerebral palsy (CP) football players. This study aimed to determine the relationships of three coordination tests with match physical load during competition of para-footballers from different sport classes. Records from 259 para-footballers from 25 national teams were obtained in four international competitions held in 2018 and 2019. The three coordination tests were conducted prior to competition (i.e., rapid heel-toe, side-stepping, and split jumps), and physical match load was recorded by GPS devices during the real game: i.e., maximum/mean, total distance, distance covered at different speed zones, number of accelerations/decelerations at different intensities, and player load. FT1 and FT3 players have the lowest and highest performance in all the coordination tests, respectively, but inconclusive between-groups differences were obtained (p=0.022‒0.238). Split jumps and side-stepping tests are associated with the performance of moderate and high accelerations during competition (r = −0.20‒0.71; p<0.01). Significant correlations (r = 0.36‒0.71; p<0.01) were obtained between all the coordination measures. Coordination tests better discriminate those with more severe impairments and some evidence for the validity of the new CP football sport classes is provided. Further research is necessary to identify the portion of the variance in sports performance that coordination explains. [ABSTRACT FROM AUTHOR]

The aim was to analyse the differences in professional handball players' injury profile according to the team's competitive-level (i.e., First division vs. Second division). Fifty-three professional male handball players participated in this study during four consecutive seasons in the same team (2015–16 and 2016–17 for the First division league and 2017–18 and 2018–19 for the Second division league). No significant differences in overall incidence were observed between groups (3.69 vs 4.19 injuries/1000 h, RR = 0.88, 95% CI 0.64–1.22, P = 0.44), although significantly greater injury incidence during training sessions was observed in the Second division group (3.06 vs 1.61 injuries/1000 h, RR = 0.52, 95% CI 0.34–0.81, P = 0.01), while greater injury incidence during matches was reported in the First division group (84.03 vs 49.88 injuries/1000 h, RR = 1.68, 95% CI 1.00–2.83, P = 0.05). The second division group presented the greatest injury burden attending to overall, training and match exposure, as well as in most locations and injury types. Given the between groups differences found in the injury profile of handball player, it is suggested to implement specific preventive strategies attending to the characteristics of each level-group. [ABSTRACT FROM AUTHOR]

The aim was to analyse the influence of the offside rule and pitch sizes on the external loads encountered by young soccer players during small-sided games (SSGs). Twenty-four U12 soccer players belonged to the same Spanish Performance Soccer Academy participated in the study. Each player participated in six different SSGs attending to the offside rule (i.e., offside not applicable [NOS] and with offside [WOS]) and the pitch sizes (i.e., individual interaction space [IIS] of 25, 50 and 75 m2 per player). The obtained data included measures of external loads by global positioning systems. Players covered higher total distance and greater distances at jogging (8–12.9 km·h−1), cruising (13.0–16.0 km·h−1) and sprinting (>16.0 km·h−1) in NOS75 and WOS75 SSGs (p < 0.01; d = 0.65–6.60). Besides, in the NOS75 SSG, the total distance and the distance at cruising were higher in respect to WOS75 (p < 0.01; d = 0.63–0.82). In addition, players performed lower sprints (p < 0.01; d = 1.17–1.71) and achieved lower Vmax (p > 0.05; d = 1.10–1.88) during NOS25 and WOS25 SSGs. These findings could provide relevant information for coaches in order to apply different pitch sizes and the inclusion/absence of the offside rule throughout the microcycle. [ABSTRACT FROM AUTHOR]

In this paper, a simple method is introduced for the computational modelling of multiphase materials, and for the approximation of their mechanical response. The two-dimensional microstructures of six asphalt concrete specimens are selected; three of the specimens have 'low'-, and three have 'high' aggregate fraction. A grid is used to divide the surface of each microstructure into square cells. The procedure of grid division is applied from 1 up to 100 divisions per side (i.e. up to 10,000 cells in the grid-divided specimen). To obtain an approximation of the mechanical response of the microstructure, the properties of the cells are estimated using three simple interpolation rules between the properties of the two phases, i.e. asphalt matrix and rock aggregates. It is found that the interpolation rules can yield reasonably representative results depending on the aggregate fraction of the microstructures and the number of divisions/cells in the grid. The grid-divided specimens allow approximating the overall mechanical response of the microstructures, and characteristics such as strain concentrations, overall deformations, and resulting force. [ABSTRACT FROM AUTHOR]

The aims of this study are 1) to compare sided games' (SGs) external responses encountered by players according to pitch size and to 2) examine the relationships between sprint performance and SGs' external physical responses. Twenty soccer players under 15 years of age (U-15) participated in this study. Each player performed a sprinting test (10 m and 30 m sprints) and played a SG on two different pitch sizes (small at 100 [SSG] and large at 200 [LSG] m2 per player). Higher external responses (p < 0.01, ES = −6.41–1.22) were found in LSG in comparison to SSG, except to distance accelerating and decelerating (p > 0.05, ES = −0.26–0.27). Players who were faster over 10 and 30 m covered higher distances cruising and sprinting (r = −0.47/-0.66; ± 0.23/± 0.30, respectively, p < 0.05), performed a greater number of sprints, achieved higher maximum velocity (Velmax) during LSG and covered a greater distance at high-intensity accelerating (r = −0.50/-0.70; ±0.21/±0.29, respectively, p < 0.05) during both SG. LSG demanded a higher external load in comparison with SSG. In addition, the improved sprint capacity could allow players to perform greater running activities and short-term actions at high-intensities during SG. [ABSTRACT FROM AUTHOR]

The aims of this study were to compare the external and internal match responses and fitness performance of national field referees (FRs) and assistant referees (ARs), and to examine the relationships between these fitness measures and physical and physiological responses during match play. Forty-four national soccer match officials (e.g. FRs and ARs) participated in this study. The distance covered and the VO2max in Yo-Yo Intermittent recovery test (YYIR1) and the 30 m sprint test correlated with high speed and high intensity activities during match play in FRs (r = −0.48–0.63, moderate to large, very likely to most likely, p < 0.05). In addition, YYIR1 performance was related to high accelerations (r = 0.41, moderate, likely, p < 0.05) and high decelerations (r = 0.44, moderate, very likely, p < 0.05) for FRs. Better sprint and cardiovascular fitness could be relevant to the performance of FRs during match play. [ABSTRACT FROM AUTHOR]

Cancer-related fatigue (CRF) is a debilitating syndrome that persists for many cancer survivors for years after treatment. Symptoms include early and persistent fatigue, functional decline, depression, and cognitive difficulties. Inflammation, assessed using pro-inflammatory biomarkers, is increased in cancer survivors with fatigue and treatments for fatigue are often aimed at reducing inflammation. Additionally, cancer and its treatment lead to nutritional complications, changes in body composition, and nutritional deficiencies that potentially weaken the cancer survivor and impact CRF. We conducted a qualitative review of clinical trials that assessed nutritional interventions for preventing and treating CRF. Further studies were examined that used nutritional interventions to address inflammation and fatigue, due to the dearth of nutrition research directly related to CRF. Dietary intake prior to, during, and after cancer treatment appears to affect fatigue levels. Increased protein intake may help preserve lean mass and body composition. Dietary patterns that reduce inflammation, such as the Mediterranean diet and other plant-based diets, appear tolerable to cancer survivors and may reduce fatigue. Supplementation with ginseng, ginger, or probiotics may improve cancer survivors' energy levels. Nutritional interventions, alone or in combination with other interventions should be considered as therapy for fatigue in cancer survivors. [ABSTRACT FROM AUTHOR]

Purpose: The main purpose of the present study was to determine physiological responses in wheelchair basketball (WB) matches in relation to heart rate (HR), match load (ML), differentiated perceived exertion (dRPE), lactate concentrations (LA), and tympanic temperature (TEMP), while specifying the individual player's playing time during different types of matches.Method: Nine Spanish First Division WB players participated in the study. Three groups were determined for each observation (i.e., HR, ML, dRPE, LA, and TEMP) according to the minutes played by the WB players: players who had played 30 min to 40 min (WB30-40), those who played 20 min to 30 min, and those who played 0 min to 20 min.Results: The WB30-40 group attained statistically significantly higher results in mean HR than the other groups in league and playoff matches (p < .05; Δ% > -25.73%; ES > -1.31, large). With regard to the difference in each variable between league and playoff matches, the differences were highlighted in the WB30-40 group according to ML (Edwards, p < .05, Δ% = -11.14%, ES = -0.87, large; Stagno's modified TRIMP, p < .05, Δ% = -16.95%, ES = -0.77, large). Tympanic temperature also reached higher values in playoff matches compared with league matches in WB30-40 (p < .05; Δ% = 1.1%; ES = 0.67, moderate) but not in LA values.Conclusions: Coaches should take into account that playoff matches were more demanding than league matches, thus forcing coaches to try to peak WB players' physical performance for the former. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to examine the changes in aerobic fitness in young elite Spanish soccer players after the pre-competitive period over 12 seasons depending on the initial performance level and the tactical position. Methods: One hundred and thirty players belonging to the same reserve team of a Spanish La Liga Club participated in this study. Aerobic fitness capacity (the velocity associated with a blood lactate concentration [La]b of 3 mmol l-1 [V3]) was assessed in each season at the start of the preseason (i.e. July), Test 1 (T1), and the start of the competitive period (i.e. September), Test 2 (T2), from 1998 to 2013 season. Results: Taking all seasons together a most likely small improvement (effect size (ES) = 0.52; ±0.09) was found in V3 after preseason, but this varied from trivial to moderate among the seasons. A most likely large improvement was found for the players with lower V3 values in T1 (ES = 1.68; ±0.38) while a likely small enhancement was assigned to the group with higher V3 values (ES = 0.53; ±0.42). Conclusions: Technical staff should be cautious about affirming an improvement in aerobic fitness after preseason. [ABSTRACT FROM AUTHOR]

The purpose of the study was to analyse the effect of two warm-up protocols of different duration on physical performance, perceived load and perception of being ready for a match in handball players. Eighteen handball players were randomly divided into two groups (Wup34min, warm-up protocol of 34 min, Wup17min, warm-up protocol of 17 min). Before and after the warm-up protocols, they performed a battery of physical tests and recorded their perception of feeling ready for a match. At the end of the warm-up protocols, all the players evaluated their differentiated perceived effort (dRPE). The results showed that neither of the protocols significantly modified (p > 0.05) the players’ physical performance. However, the Wup34min group showed higher values in the differentiated warm-up perceived load (dRPE-WL) (p < 0.01, TE = 0.97-1.27, high) than the Wup17min group. The players with a greater perceived muscular load (RPEMUSC) experienced a greater decrease in their acceleration capacity (r = 0.48-0.49, p < 0.05). In spite of the fact that neither of the warm-up protocols significantly modified the players’ physical performance, a greater perceived muscular load may cause a greater decrease in acceleration capacity. [ABSTRACT FROM AUTHOR]

The response and degradation of the hot mix asphalt (HMA) materials used in pavement structures are affected by their inherent heterogeneity. The objective of this work is to study the impact of two different sources of HMA heterogeneity in the uncertainty of the mechanical moisture degradation of HMA. The first source of heterogeneity is the spatial variability of the properties of the bulk fine aggregate matrix (FAM) of the mixture, and the second is the location and shape of the coarse aggregate particles. The heterogeneity of the bulk FAM phase was modelled using a random field technique, while that of the coarse aggregates was accounted for by randomly generating realistic probable sets of aggregate particles. Thus, ‘computational replicates’ of HMA microstructures were generated and subjected to moisture diffusion and mechanical loading using a finite element approach. In the mechanical simulations, a non-linear viscoelastic moisture damage constitutive relationship based on continuum damage mechanics theory was selected to characterise the response of the bulk FAM phase. The results show that conducting computational simulations with realistic HMA microstructures that properly capture the heterogeneity of the material is useful to quantify the mean values and dispersion (i.e. uncertainty) associated with the response and degradation of the mixture. This information, which cannot be easily obtained in the field or in the laboratory due to the difficulty of acquiring a sufficient amount of data, is useful to conduct structural reliability analysis and to predict the life cycle behaviour of the material. [ABSTRACT FROM AUTHOR]

This essay questions Daniel Bell Jr.'s claim that liberation theology is ignorant of the links between the cultural and structural formations of capitalism. Focusing especially on Bell's treatment of the thought of Gustavo Gutiérrez, the article argues that Gutiérrez's concept of integral liberation provides a complex account of the manner in which the structural, cultural, and theological levels of liberation are interrelated. It contends, contra Bell, that Gutiérrez's concept does not reduce politics to “statecraft” but instead provides an illuminating framework for understanding the integrity of Christian life within the contemporary neoliberal globalization project. Finally, the paper moves to consider the manner in which Gutiérrez's concept might be fruitfully paired with Leslie Sklair's theorization of global capitalism in order to specify the process of liberation today. [ABSTRACT FROM PUBLISHER]

The aims of this study are (a) to describe the evolution of neuromuscular performance over an 18 year period within a Spanish elite reserve team; (b) to check if there were any relation between the playing position and sprint and jump performances and (c) to look into the alleged impact of this factor on the top playing level attained by the soccer players. We considered the physical tests (5 m and 15 m sprint times and countermovement jump (CMJ) height) made by 235 players enrolled in the reserve team of the Club from 1994 to 2012 and the highest competitive-level they achieved: Spanish first (n = 39) and second divisions (n = 36) and semi-professional (n = 160). Furthermore, the players were classified according to their playing positions. The main findings were a very-likely/most-likely lower neuromuscular performance (ES = 0.48–0.68, small to moderate) in the last six-season term (2006–2012) than in the first term (1994–2000); possibly/very-likely lower performances in sprinting and CMJ (ES = 0.22–0.55, small) by central defenders (CDs) and midfielders than by other playing positions; very-likely better performances in sprinting and jumping by first and second divisions central defenders than by semi-professional central defenders (ES = 0.90–1.02, moderate). Sprint and jump performances are not a relevant physical parameter to promote to the top level of soccer in Spain except for one in six of the playing positions: CDs. [ABSTRACT FROM PUBLISHER]

The aim of this study was to examine the dose response effect of strength and conditioning programmes, involving horizontally oriented plyometric exercises, on relevant soccer performance variables. Sixteen soccer players were randomly allocated to two 6-week plyometric training groups (G1 and G2) differing by imposed (twice a week) training volume. Post-training G1 (4.13%; d = 0.43) and G2 (2.45%; d = 0.53) moderately improved their horizontal countermovement jump performance. Significant between-group differences (p < 0.01) in the vertical countermovement jump for force production time (T2) were detected post-training. No significant and practical (p > 0.05, d = trivial or small) post-training improvements in sprint, change of direction ability (CODA) and horizontal arm swing countermovement jump were reported in either group. Horizontal plyometric training was effective in promoting improvement in injury prevention variables. Doubling the volume of a horizontal plyometric training protocol was shown to have no additional effect over functional aspects of soccer players' performance. [ABSTRACT FROM AUTHOR]

The aim of this study was to quantify the acute impact of soccer match officiating on selected physiological and physical performance measures. Twenty-four officials from the Spanish National 3rd Division participated in this study. External global positioning system and internal (heart rate) load data were collected for each match official during 8 official matches. Pre- and post-matches, the referees were assessed for tympanic temperature, blood lactate, 15- and 30-m sprint speeds and unilateral (dominant and non-dominant legs) and bilateral vertical jump performances. For referees, the acute physiological and physical performance effects of officiating (post-match value minus pre-match value) were large increases in blood lactate (1.7 mmol · l−1; ±90% confidence limit, 0.9 mmol · l−1; effect size, ES = 4.35), small increases in 15-m sprint (0.09; ±0.04 s; ES = 0.53) and 30-m sprint speeds (0.14; ±0.08 s; ES = 0.39) and a small increase in non-dominant leg jump performance (2.1; ±1.4 cm; ES = 0.31). For assistant referees, there was a small decrease in tympanic temperature (−0.3°C; ±0.2°C; ES = −0.65) and small increases in blood lactate (0.4; ±0.3 mmol · l−1; ES = 0.66), 15-m sprint speed (0.06; ±0.04 s; ES = 0.47), 30-m sprint speed (0.11; ±0.16 s; ES = 0.49) and bilateral countermovement jump height (3.4; ±1.5 cm; ES = 0.45). Taken together, these data demonstrate that the physical demands of soccer officiating are sufficient to elicit increases in blood lactate and small decrements in sprint performance and, thereby, provide some evidence for match-related fatigue. [ABSTRACT FROM AUTHOR]

Moisture diffusion is one of the mechanisms by which water can reach the microstructure of asphalt mixtures and negatively affect their performance. In this work, a finite element model and computational simulations were used to study the response of asphalt pavement layers subjected to the coupled effects of moisture diffusion and mechanical loading. The model considered that the evolution of water-related diffusion processes in these materials is influenced by the microstructure of the mixture, particularly by the air void (AV) phase. Thus, a stochastic technique was used to incorporate the heterogeneity of the AV structure in compacted asphalt layers, which also permitted to account for the variability of the physical and mechanical properties that result from the heterogeneous void structure. The results demonstrate that moisture diffusion has a significant influence on the macromechanical response of asphalt pavement layers, especially during the initial months of service. In addition, the results clearly demonstrate that including the heterogeneity of material properties is valuable to quantify the uncertainty associated with these coupled processes. [ABSTRACT FROM PUBLISHER]

This paper evaluates the role of the air voids (AV) variability of asphalt mixtures on the thermo-mechanical response of asphalt courses. The methodology presented combines finite element (FE) modelling with a stochastic technique called random fields. This technique is used to generate probable spatial AV distributions in the geometry of compacted asphalt courses. Thus, several asphalt layers with AV contents varying in space were implemented in FEs, and a thermal diffusion process followed by a mechanical loading scheme was simulated. The mechanical response of the asphalt course was made dependent on both the specific AV content and temperature at each point within the layer. It was found that the quality of the compaction process, represented by the dispersion of the AV, strongly impacts the thermal diffusion processes and the uncertainty of the mechanical response of asphalt courses. [ABSTRACT FROM PUBLISHER]

The cycad aulacaspis scale (CAS),Aulacaspis yasumatsuiTakagi (Hemiptera: Diaspididae), is a serious pest of ornamental cycads in the southeastern United States. In Florida, CAS was first reported in Miami in 1996 and is now present in 43 Florida counties. Chemical control of CAS can be effective, but it is expensive, and insecticides must be frequently and regularly applied. Recent surveys of natural enemies in Thailand identified a new potential biological control agent of CAS. The objective of this study was to examine the temperature requirements and consumption rates ofPhaenochilus kashayaGiorgi and Vandenberg (Coleoptera: Coccinellidae). Survival, developmental time and number of scales consumed byP.kashayawere measured at four constant temperatures (20, 25, 30 and 35°C). In addition, adult longevity and consumption were recorded at three constant temperatures (20, 25 and 30°C).Phaenochilus kashayacompleted development to adulthood at temperatures ranging from 20 to 30°C. The highest survival rate (48%) was obtained at 25°C, and the accumulated degree-days for this species was 714.Phaenochilus kashayais a voracious predator of CAS, consuming 380 scales during the larval stage and an estimated 4700 scales during the adult stage. Adult longevity varied from 59 days at 30°C to 220 days at 20°C for females, and 31 days at 30°C to 148 days at 20°C for males. The intrinsic rate of increase (rm) was 0.34 at 20°C, which is high compared with other coccinellid species. According to this study,P. kashayahas the potential to be an effective biological control agent of the CAS in Florida. [ABSTRACT FROM AUTHOR]