bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validity of the Yo‐Yo intermittent endurance test in young soccer players
Authors: Wong Pui‐Lam , Chaouachi Anis , Castagna Carlo , Lau Patrick W. C. , Chamari Karim , Wisløff Ulrik 
Published: September 2011

AbstractThe Yo‐Yo intermittent endurance test is frequently used to assess aerobic endurance performance in young soccer players but only the logical validity of the test has been shown to date. The main ai m of this study was to assess the criterion (i.e. association with maximal aerobic capacity, [Vdot]O2max) and construct validities of the test in young soccer players. A secondary aim was to examine possible shared variance of the Yo‐Yo intermittent endurance test with other physical capacities. Sixty‐two soccer players (age 13.7±0.5 years) from an Under‐14 team participated. All players performed a battery of fitness tests to assess [Vdot]O2max, aerobic endurance performance (Yo‐Yo intermittent endurance test), soccer dribbling endurance performance (Hoff dribbling test), and power performance (maximal vertical jump, 30‐m sprint with 10‐m split time). Results showed that the Yo‐Yo intermittent endurance test was strongly correlated with [Vdot]O2max (r=0.63, P<0.001), thereby showing the test's criterion validity. Players with the best performance on the Yo‐Yo intermittent endurance test had significantly higher [Vdot]O2max (P<0.001, large effect), and significantly better soccer dribbling endurance (P<0.001, large effect) and 30‐m sprint times (P<0.05, medium effect). Logistic regression (r=0.79, P=0.0001) showed that Hoff dribbling test performance (explained variance=50.4%), [Vdot]O2max (explained variance=39.7%), and 30‐m sprint time (explained variance=14.4%) were significant independent parameters contributing to performance on the Yo‐Yo intermittent endurance test. Therefore, the Yo‐Yo intermittent endurance test is a valid on‐field aerobic endurance performance test for young soccer players, which can also be used to differentiate the maximal aerobic capacity, soccer dribbling endurance, and 30‐m sprint performance of these players.
Peripheral alterations after two different concentric power protocols
Authors: Tomazin Katja , Millet Guillaume Y. , Ulaga Maja , Jereb Blaz , Strojnik Vojko 
Published: September 2011

AbstractThe aims of the present study were to assess the ability of explosive concentric contractions to induce high‐frequency fatigue, and to determine what effects the number of repetitions and number of sets have upon peripheral fatigue. Nine male students performed two protocols (6 sets, 5 min and 1 week rest between sets and protocols, respectively) with a different number of concentric jumps in a set on the sledge (10 vs. 20 jumps in the first (S10) and the second protocol (S20), respectively). Isometric twitch torque, torque during low‐frequency (20 Hz) and high‐frequency (100 Hz) electrical stimulation of the vastus lateralis were measured (before protocols and 30 s after sets). Peak twitch torque increased, while contraction and half‐relaxation times shortened during the S10 protocol (P<0.05). The increase in peak twitch torque was accompanied by non‐significant reductions in contraction time and half‐relaxation time in the S20 protocol. High‐ and low‐frequency torques did not change significantly in either protocol. The high‐ to low‐frequency torque ratio increased significantly (P<0.05) after the fourth set in the S10 protocol. Post‐activation potentiation was the main reason for enhanced contractile response after both protocols. There were no alterations in high‐frequency torque or reductions in the high‐ to low‐frequency torque ratio, even with increased sets and repetitions. Explosive concentric contractions showed no potential to induce high‐frequency fatigue, when separated with long periods of rest.
Influence of technical instructions on the physiological and physical demands of small‐sided soccer games
Authors: Dellal Alexandre , Chamari Karim , Owen Adam Lee , Wong Del P. , Lago‐Penas Carlos , Hill‐Haas Stephen 
Published: September 2011

AbstractThe aim of the present study was to examine the effects of changes in the number of ball contacts allowed per individual possession on the physiological, technical, and physical demands within small‐sided games in elite soccer. Twenty international players (age 27.4±1.5 years, body mass 79.2±4.2 kg, height 1.81±0.02 m, velocity at [Vdot]O2max 17.4±0.8 km ·h−1, percent body fat 12.7±1.2%) performed three different small‐sided game formats (i.e. 2 vs. 2; 3 vs. 3; 4 vs. 4) on three different occasions in which the number of ball contacts authorized per possession was fixed (one touch, two touches, and free play). The relative pitch per player ratio was similar for all small‐sided games. The small‐sided games were performed with four support players (placed around the perimeter of pitch) with instructions to keep possession of the ball. The total duration of the small‐sided games was the effective time of play. The physical demands, technical requirements, heart rates, post‐exercise blood lactate concentrations, and ratings of perceived exertion (RPE) were assessed. The percentages of successful passes and numbers of duels were significantly lower when the small‐sided game was played with one touch (P<0.001), whereas the number of balls lost increased (P<0.001 for 2 vs. 2 and 3 vs. 3; P<0.01 for 4 vs. 4). The small‐sided game played with one touch also induced increases in blood lactate concentration and RPE, as well as greater physical demands in the total distance covered in sprinting and high‐intensity runs. In conclusion, the main findings of this study are that by altering the number of ball contacts authorized per possession in small‐sided games, the coach can manipulate both the physical and technical demands within such games.
Social isolation and physical inactivity in older US adults: Results from the Third National Health and Nutrition Examination Survey
Authors: Reed Sharon B. , Crespo Carlos J. , Harvey William , Andersen Ross E. 
Published: September 2011

AbstractPhysical inactivity is a risk factor for cardiovascular and other chronic diseases. It has been shown that both physical inactivity and social isolation increase with age, and that these factors are detrimental to physical and mental well‐being. The purpose of the present study was to examine the relationship between physical inactivity and social isolation in older US adults. Using data from a nationally representative cross‐sectional survey, the Third National Health and Nutrition Examination Survey, 1988–1994, we assessed the age‐ and race‐specific prevalence of no leisure‐time physical activity in relation to various forms of social interaction. The prevalence of no leisure‐time physical activity increases with age in both men and women. In non‐Hispanic whites, non‐Hispanic blacks, and Mexican Americans, the prevalence of no leisure‐time physical activity is increased in older US adults who are socially isolated. Social isolation is related to physical inactivity among persons 60 years and older. Longitudinal and intervention studies are needed to establish whether increased social support translates to a more active population of older adults.
A multidisciplinary identification model for youth handball
Authors: Matthys Stijn P. J. , Vaeyens Roel , Vandendriessche Joric , Vandorpe Barbara , Pion Johan , Coutts Aaron J. , Lenoir Matthieu , Philippaerts Renaat M. 
Published: September 2011

AbstractTalent identification in team sports is complex and requires a multidisciplinary approach. The purpose of this study was to examine differences between elite and non‐elite handball players in three age groups: U14 (n=186), U16 (n=150), and U18 (n=92). A multidimensional test battery was assessed, taking biological maturation into account. Significant maturation effects were found for all anthropometric characteristics and most performance variables. Compared with their non‐elite peers, the elite handball players demonstrated significantly greater aerobic capacity (P<0.01), strength and power (U14: countermovement jump, P=0.021; sit‐ups, P=0.003; handgrip, P=0.020; U16: countermovement jump, P=0.013; five‐jump test, P<0.001), and speed and agility (P<0.05) when maturation was controlled for. There was a significant difference in flexibility between elite and non‐elite players in the U18 group (P<0.05). The elite and non‐elite players did not differ in task‐ and ego‐orientation. These results show that elite and non‐elite young handball players possess different physical performance characteristics and that the specific tests that discriminate elite from non‐elite handball players vary among age groups. In addition, maturity status can influence the results and should therefore be considered in talent identification and development programmes.
Effects of aerobic versus resistance training on glycaemic control in men with type 2 diabetes
Authors: Moe Børge , Augestad Liv Berit , Åsvold Bjørn Olav , Flanders William Dana 
Published: September 2011

AbstractThe aim of this study was to compare the effects of aerobic training and resistance training on glycaemic control factors in men with type 2 diabetes. We performed a randomized clinical trial in which 26 men (age 57±8 years) with type 2 diabetes were randomly assigned to an aerobic training group or a resistance training group. The participants exercised three times a week for 12 weeks. Metabolic factors (haemoglobin A1C; fasting glucose and C‐peptide; total, LDL, and HDL cholesterol; triglycerides), blood pressure, body composition, maximum oxygen uptake, and muscular strength were measured before and after the intervention. Both training groups experienced significant improvements in haemoglobin A1C: the aerobic training group saw a decrease in absolute values from 7.10±0.97% to 6.55±0.74% (P=0.001) and the resistance training group from 7.21±1.8% to 6.85±0.66% (P=0.024). Both training groups had significant improvements in systolic and diastolic blood pressure (P<0.05) and in several of the measured body composition variables (P<0.05). In conclusion, the aerobic and resistance training groups saw similar improvements in glycaemic control. This suggests that both aerobic training and resistance training have beneficial effects for men with type 2 diabetes.
Executive Summary: The Management of Community-Acquired Pneumonia in Infants and Children Older Than 3 Months of Age: Clinical Practice Guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America
Authors: Bradley John S. , Byington Carrie L. , Shah Samir S. , Alverson Brian , Carter Edward R. , Harrison Christopher , Kaplan Sheldon L. , Mace Sharon E. , McCracken George H. , Moore Matthew R. , St Peter Shawn D. , Stockwell Jana A. , Swanson Jack T. 
Published: September 2011

Abstract

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.
Chemerin levels are positively correlated with abdominal visceral fat accumulation
Authors: Shin Hyun‐Young , Lee Duk C. , Chu Sang H. , Jeon Justin Y. , Lee Mi K. , Im Jee A. , Lee Ji W. 
Published: September 2011

SummaryObjective  Chemerin, a recently discovered adipocytokine, may be linked to obesity and obesity‐associated metabolic complications. However, the relationship between visceral fat accumulation and chemerin is still unknown. Therefore, we investigated the relationship between serum chemerin levels and body composition as measured by computed tomography (CT).Patients  We recruited 173 men and women without histories of diabetes or cardiovascular disease.Measurements  Biomarkers of metabolic risk factors and body composition by computed tomography were assessed. Serum chemerin levels were measured by enzyme‐linked immunosorbent assay.Results  Chemerin levels correlated with body mass index (BMI), waist circumference, abdominal visceral fat area, blood pressure, fasting insulin, homoeostasis model of assessment‐insulin resistance, total cholesterol, triglyceride, creatinine, aspartate aminotransferase and alanine aminotransferase. By stepwise multiple regression analysis, abdominal visceral fat area, blood pressure and total cholesterol levels independently affected chemerin levels.Conclusions  Abdominal visceral fat accumulation, blood pressure and lipid profile were significantly associated with serum chemerin levels. Our findings suggest that chemerin may be a mediator that links visceral obesity to cardiovascular risk factors.
Thrombin generation in type 2 diabetes with albuminuria and macrovascular disease
Authors: Ay Leyla , Hoellerl Florian , Ay Cihan , Brix Johanna‐Maria , Koder Silvia , Schernthaner Gerit‐Holger , Pabinger Ingrid , Schernthaner Guntram 
Published: September 2011

Eur J Clin Invest 2012; 42 (5): 470–477AbstractBackground  Albuminuria is an indicator of cardiovascular morbidity and mortality in patients with type 2 diabetic mellitus (T2DM).Materials and methods  In our cross‐sectional study, we measured thrombin generation (TG), a key process in haemostasis and a tool to detect an individual’s coagulation potential, in normo‐, micro‐ and macroalbuminuria in T2DM with and without macrovascular disease (MVD). The TG‐assay was performed, and the TG‐curve [including the lag phase, peak thrombin and area under the curve (AUC)] was analysed.Results  A total of 160 patients (62 women; mean age ± SD: 67 ± 11 years) with T2DM and normo‐, micro‐ or macroalbuminuria were investigated. Of those, 90 (56%) patients had normoalbuminuria, 40 (25%) microalbuminuria and 30 (19%) macroalbuminuria. The AUC between the groups of patients with normo‐, micro‐ and macroalbuminuria was statistically significantly different [3297 (2785; 3764) vs. 3222 (2381; 3678) vs. 3726 (3153; 4235) nM Thrombin; P = 0Æ019]. T2DM patients with MVD (n = 121) had a significantly shorter lag phase [12 (9; 16) vs. 20 (15; 25) min; P < 0Æ001], a significantly higher peak thrombin [233 (130; 339) vs. 133 (82; 187) nM; P < 0Æ001] and a significantly higher AUC [3464 (2969; 3868) vs. 3091 (2384; 3619) nM Thrombin; P = 0Æ01] than T2DM patients without MVD (n = 39), indicating an earlier and higher thrombin generation.Conclusion  Our results support the hypothesis that TG may be involved in the pathogenesis of MVD in diabetic nephropathy as for the first time, we could show that patients with T2DM in different stages of diabetic nephropathy had disturbances in thrombin generation.
The energetic cost of exposure to UV radiation for tadpoles is greater when they live with predators
Authors: Alton Lesley A. , White Craig R. , Wilson Robbie S. , Franklin Craig E. 
Published: September 2011

Summary1. Global increases in ultraviolet‐B radiation (UVBR) associated with stratospheric ozone depletion are thought to be contributing to the rapid disappearance of amphibian populations from pristine habitats around the world. Much research has been dedicated to understanding the effects of ultraviolet radiation (UVR) alone and in combination with other environmental stressors on the early life stages of amphibians. Little is known, however, of how UVR affects amphibian metabolism, or how amphibian metabolism may change in response to exposure to other stressors in addition to UVR.2. Using a controlled laboratory experiment, we examined the independent and interactive effects of UVR and non‐lethal predatory chemical cues (PCC) on the tissue and whole‐animal metabolic rate (MR) and activity of striped marsh frogLimnodynastes peroniitadpoles. PCC signal risk of predation, which is a natural stressor that can cause tadpoles to alter their behaviour, morphology, and life history, and for which the metabolic cost remains little explored.3. We found that exposure to UVR caused tissue MR to increase by 36%, but whole‐animal MR to decrease by 14%, which is most likely due to tadpoles reducing their activity levels by 56%. Exposure to PCC had no significant effect on tissue or whole‐animal MR, but caused tadpoles to reduce their activity levels by 36%, indicating that the whole‐animal MR of tadpoles exposed to PCC is elevated relative to their activity levels. Compared with tadpoles exposed to neither stressor, tadpoles exposed simultaneously to UVR and PCC showed no change in whole‐animal MR despite reducing their activity levels by 62%.4.This research shows that, for tadpoles, there is an energetic cost associated with being exposed to UVR and PCC independently, and that this cost is greater when they are exposed to both stressors simultaneously. Our previous research has shown that exposure of tadpoles to PCC enhances the lethal effects of UVR, and the present study suggests that this synergistic interaction may arise as a consequence of the effect of these combined stressors on MR. Global increases in UVBR may therefore be contributing to amphibian population declines by compromising energy allocation towards growth and development as well as energy allocation towards coping with additional environmental stressors.
Selection of reference genes in peanut seed by real‐time quantitative polymerase chain reaction
Authors: Jiang Shengjuan , Sun Yujun , Wang Songhua 
Published: September 2011

SummaryReal‐time quantitative polymerase chain reaction (qPCR) is a powerful tool for quantifying gene expression, combining both high sensitivity and specificity with efficient signal detection. Choosing the ‘correct’ normalisation control is essential and critical for obtaining reliable expression data. In this article, ten reference genes from Arachis hypogaea were analysed as internal controls for gene expression assay by using qPCR in two tissues of the seed, including embryo and cotyledon. The results showed that phospholipase D and actin were the most stable genes, whereas tubulin B4 and polyubiquitin 10 should be avoided when doing gene expression analysis because of their high variabilities in those tissue types. Although phospholipase D was scored as the most stable gene, it should be carefully validated for each particular experiment because it was easily regulated by different conditions. Taken together, actin was concluded as the optimal reference gene for studying gene expression in the mature peanut seed.
Vegetation recovery in a desert landscape after wildfires: influences of community type, time since fire and contingency effects
Authors: Engel E. Cayenne , Abella Scott R. 
Published: September 2011

Summary1. Theories of plant succession are poorly developed in arid lands, hindering our understanding of how long communities may take to recover after disturbances such as fire. In desert landscapes vulnerable to fire, information about vegetation recovery is important when deciding whether land managers should facilitate vegetation recovery. The deserts of the southwestern USA are increasingly subject to unprecedented fires, facilitated by fuel from exotic grasses, yet management strategies are unclear.2. We evaluated post‐fire recovery patterns of perennial plant species richness and diversity, compared the rate and direction of succession between two major community types, and explored the relationship of time since fire (TSF) and other environmental factors with vegetation recovery. We sampled perennial plant communities and environmental variables (e.g. soil N) on 32 burns, ranging from 2 to 29 years TSF and each paired with their own unburned area, within a 1·8 million ha landscape in the Mojave Desert, USA.3. Species richness, diversity and composition exhibited different post‐burn recovery patterns, and recovery rates differed between community types. Specifically, diversity in Coleogyne ramosissima communities was greater in burned than unburned areas, but diversity did not differ in Larrea tridentata communities. Species composition in Larrea communities exhibited trajectories that indicate convergence with unburned community composition after 19 years TSF. Conversely, burned and unburned Coleogyne communities lacked convergence irrespective of TSF. Environmental variables (e.g. soil texture and P) accounted for 79–83% of the variation in burned species composition, suggesting environmental characteristics in part control recovery patterns.4.
Synthesis and applications. The results indicate that geographically similar vegetation types within the same landscape can have markedly different post‐disturbance successional rates and trajectories. Furthermore, the persistence of fire effects varied depending on the community measure, with fire effects on species composition more long‐lasting than the effects on species diversity. This work supports (i) the use of post‐disturbance successional analyses for helping to prioritize management where it is most needed (e.g. communities not recovering naturally) and (ii) the need to assess whether persistent, early successional desert communities meet functional management objectives.
‘Out‐of‐Africa’ dispersal of tropical floras during the Miocene climatic optimum: evidence fromUvaria(Annonaceae)
Authors: Zhou Linlin , Su Yvonne C. F. , Thomas Daniel C. , Saunders Richard M. K. 
Published: September 2011

AbstractAim African–Asian disjunctions are common in palaeotropical taxa, and are typically explained by reference to three competing hypotheses: (1) ‘rafting’ on the Indian tectonic plate, enabling Africa‐to‐Asia dispersal; (2) migration via Eocene boreotropical forests; and (3) transoceanic long‐distance dispersal. These hypotheses are tested usingUvaria(Annonaceae), which is distributed in tropical regions of Africa, Asia and Australasia. Recent phylogenetic reconstructions of the genus show a clear correlation with geographical provenance, indicating a probable origin in Africa and subsequent dispersal to Asia and then Australasia. Ancestral areas and migration routes are inferred and compared with estimates of divergence times in order to distinguish between the prevailing dispersal hypotheses.Location Palaeotropics.Methods Divergence times inUvariaare estimated by analysing the sequences of four DNA regions (matK,psbA–trnH spacer,rbcL andtrnL–F) from 59Uvariaspecies and 77 outgroup species, using a Bayesian uncorrelated lognormal (UCLD) relaxed molecular clock. The ancestral area ofUvariaand subsequent dispersal routes are inferred using statistical dispersal–vicariance analysis (s‐diva).Results Uvariais estimated to have originated in continental Africa 31.6 Ma [95% highest posterior density (HPD): 38.4–25.1 Ma] between the Middle Eocene and Late Oligocene. Two main migration events during the Miocene are identified: dispersal into Madagascar around 17.0 Ma (95% HPD: 22.3–12.3 Ma); and dispersal into Asia between 21.4 Ma (95% HPD: 26.7–16.7 Ma) and 16.1 Ma (95% HPD: 20.1–12.1 Ma).Main conclusions Uvariafruits are widely reported to be consumed by primates, and are therefore unlikely candidates for successful long‐distance transoceanic dispersal. The other biogeographical hypotheses, involving rafting on the Indian tectonic plate, and dispersal via the European boreotropical forests associated with the Eocene thermal maximum, can be discounted due to incongruence with the divergence time estimates. An alternative scenario is suggested, involving dispersal across Arabia and central Asia via the tropical forests that developed during the late Middle Miocene thermal maximum (17–15 Ma), associated with the ‘out‐of‐Africa’ dispersal of primates. The probable route and mechanism of overland dispersal between Africa and Asia for tropical plant groups during the Miocene climatic optimum are clarified based on theUvariadata.