180 research outputs found

    Relationship between power condition, agility, and speed performance among young roller hockey elite players

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    Purpose. The study was intended to describe the correlations between speed performance (11 m, 22 m, and 33 m) and agility test in skates with determinants of muscular power (squat jump, countermovement jump) in young Portuguese roller hockey athletes involved in a regional selection. Methods. A cross-sectional study was conducted among 10 male roller hockey players with mean (? SD) age of 14.20 (0.57) years, involved in the Portuguese national competition of under-15, making part of the final Oporto district selection of players to participate in inter-regional selections competition. Their mean (? SD) weight, height, body mass index, and sum of the skinfolds were 58.62 (8.78) kg, 165.72 (8.45) cm, 21.26 (1.52) kg/m2, 51.80 (14.91) mm, respectively. Furthermore, it strength was measured with squat jump and countermovement jump; sprinting time at 11 m, 22 m, and 33 m was determined, as well as time in an agility t-test, conducted in roller skating. Spearman correlation coefficients were calculated to test the associations. Results. Significant inverse correlations between vertical jumps, a practical method of power training monitoring, and linear velocity in skating (countermovement jump vs. speed, ?0.78) were found. Despite the increasing complexity of the agility test, a moderate inverse correlation with strength was observed, too (?0.48). Conclusions. Lower limbs explosive strength turned out a strong predictor of skating linear speed and agility among young roller hockey players, providing a simple evaluation tool of important determinants of performance.D915-7373-ED16 | Cesar LeaoN/

    Anthropometric profile of soccer players as a determinant of position specificity and methodological issues of body composition estimation

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    The aim of the present study was (a) to describe the anthropometric profile of a large group of soccer players based on different age groups and their playing positions on the field, and (b) to examine the variations of body composition among adult soccer players using diverse equations based on skinfold thickness. A total of 618 Greek soccer players who were grouped by age (i.e.,12?14, 14?16, 16?18, and 18?37 years) and playing position (i.e., goalkeeper, defender, midfielder, and forward) were evaluated for weight, height, and skinfolds. The Pa?r?zkov? formula was used to estimate the percentage of body fat. Furthermore, for players who were 18 years or older the Reilly and Evans formulas was used to estimate the percentage of body fat. Independent of the age, in this large sample, goalkeepers presented higher values for weight, height and the percentage of body fat estimation as compared with other field positions. An anthropometric pattern was observed in each tactical position, namely, across a specific age of increasing maturation process (14?16 years). With the Pa?r?zkov? formula, we found a mean (SD) range of variation in the percentage of body fat estimation between 4.87 ? 1.46 and 5.51 ? 1.46 as compared with the Evans formula. The same pattern of differences was found when the Reilly equation was considered. In conclusion, we observed a position specificity of anthropometric characteristics across different age categories. Additionally, the same data supported different validated equations which resulted in large differences in the final outcome estimations.D915-7373-ED16 | Cesar LeaoN/

    effects of the pre-season period

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    Study aim: To assess changes in physical fitness of amateur soccer players after a pre-season training period and baseline fitness dependencies. Material and methods: Twenty-one amateur soccer players were assessed during the pre-season. The following physical vari ables were assessed before and after a two-month pre-season training period: (i) cardiorespiratory fitness, (ii) strength and power, and (iii) change of direction (COD). Results: Significant decreases were found for countermovement jump (CMJ) (p < 0.001; d = 1.161), drop jump (DJ) (p = 0.014; d = 0.958), and horizontal jump (HJ) (p = 0.042; d = 0.640), while no significant changes were found for the overall variables from the beginning to the end of pre-season. Fit players revealed significant decreases for CMJ (p = 0.002; d = ?2.495), DJ (p = 0.004; d = ?1.760), HJ (p = 0.028; d = ?1.005), COD deficit (p = 0.034; d = 1.013), and maximal aerobic speed (MAS) (p = 0.026; d = ?4.053). No significant changes were found for unfit players. Conclusions: Amateur soccer coaches should consider assessing physical qualities at the beginning of pre-season and use the free-of-charge monitoring tools such as session-rate of perceived exertion (s-RPE) during the training process.D915-7373-ED16 | Cesar LeaoN/

    Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

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    The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L−1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure

    Severity of acute hepatitis and its outcome in patients with dengue fever in a tertiary care hospital Karachi, Pakistan (South Asia)

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    <p>Abstract</p> <p>Background</p> <p>Liver injury due to dengue viral infection is not uncommon. Acute liver injury is a severe complicating factor in dengue, predisposing to life-threatening hemorrhage, Disseminated Intravascular Coagulation (DIC) and encephalopathy. Therefore we sought to determine the frequency of hepatitis in dengue infection and to compare the outcome (length of stay, in hospital mortality, complications) between patients of Dengue who have mild/moderate (ALT 23-300 IU/L) v/s severe acute hepatitis (ALT > 300 IU/L).</p> <p>Methods</p> <p>A Cohort study of inpatients with dengue viral infection done at Aga Khan University Hospital Karachi. All patients (≥ 14 yrs age) admitted with diagnosis of Dengue Fever (DF), Dengue Hemorrhagic Fever (DHF) or Dengue Shock Syndrome (DSS) were included. Chi square test was used to compare categorical variables and fischer exact test where applicable. Survival analysis (Cox regression and log rank) for primary outcome was done. Student t test was used to compare continuous variables. A p value of less than or equal to 0.05 was taken as significant.</p> <p>Results</p> <p>Six hundred and ninety nine patients were enrolled, including 87% (605) patients with DF and 13% (94) patients with DHF or DSS. Liver functions tests showed median ALT of 88.50 IU/L; IQR 43.25-188 IU/L, median AST of 174 IU/L; IQR 87-371.5 IU/L and median T.Bil of 0.8 mg/dl; IQR 0.6-1.3 mg/dl. Seventy one percent (496) had mild to moderate hepatitis and 15% (103) had severe hepatitis. Mean length of stay (LOS) in patients with mild/moderate hepatitis was 3.63 days v.s 4.3 days in those with severe hepatitis (P value 0.002). Overall mortality was 33.3% (n = 6) in mild/moderate hepatitis vs 66.7% (n = 12) in severe hepatitis group (p value < 0.001). Cox regression analysis also showed significantly higher mortality in severe hepatitis group (H.R (4.91; 95% CI 1.74-13.87 and P value 0.003) and in DHF/DSS (5.43; CI 1.86-15.84 and P value 0.002). There was a significant difference for the complications like Bleeding (P value < 0.001), Acute Renal failure (ARF) (P value 0.002), Acalculus cholecystitis (P value 0.04) and encephalopathy (P value 0.02) in mild/moderate and Severe hepatitis groups respectively.</p> <p>Conclusion</p> <p>Severe hepatitis (SGPT>300IU) in Dengue is associated with prolonged LOS, mortality, bleeding and RF.</p

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills, and gut morphology

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    Copyright © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society1. Behavioural and physiological deficiencies are major reasons why reintroduction programs suffer from high mortality when captive animals are used. Mitigation of these deficiencies is essential for successful reintroduction programs. 2. Our study manipulated early developmental diet to better replicate foraging behaviour in the wild. Over two years we hand-reared 1800 pheasants (Phasianus colchicus), from one day old, for seven weeks under different dietary conditions. In year one, 900 pheasants were divided into three groups and reared with (i) commercial chick crumb, (ii) crumb plus 1% live mealworm or (iii) crumb plus 5% mixed seed and fruit. In year two, a further 900 pheasants were divided into two groups and reared with (i) commercial chick crumb or (ii) crumb plus a combination of 1% mealworm and 5% mixed seed and fruit. In both years the commercial chick crumb acted as a control treatment, whilst those with live prey and mixed seeds and fruits mimicking a more naturalistic diet. After seven weeks reared on these diets pheasants were released into the wild. 3. Post release survival was improved with exposure to more naturalistic diets prior to release. We identified four mechanisms to explain this. Pheasants reared with more naturalistic diets: 1) foraged for less time and had a higher likelihood of performing vigilance behaviours; 2) were quicker at handling live prey items; 3) were less reliant on supplementary feed which could be withdrawn; 4) developed different gut morphology. 4. These mechanisms allowed the pheasants to: 1) reduce the risk of predation by reducing exposure time whilst foraging, while allowing more time to be vigilant; 2) be better at handling and discriminating natural food items, and not be solely reliant on supplementary feed; 3) have a better gut system to cope with the natural forage after the cessation of supplementary feeding in the spring. 5. Learning food discrimination, preference and handling skills by the provision of a more naturalistic diet is essential prior to the release of pheasants in a reintroduction program. Subsequent diet, foraging behaviour, gut morphology and digestive capabilities all work together as one nutritional complex. Simple manipulations during early development can influence these characteristics to better prepare an individual for survival upon release.Game and Wildlife Conservation TrustERC Consolidator AwardUniversity of Exete
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