378 research outputs found
Torque-angle-velocity relationships and muscle performance of professional and youth soccer players
Soccer matches consist of a variety of different activities, including repeated sprints. Time to attain velocity (TTAV), load range (LR) and the torque-angle-velocity relationship (TAV3D) represent an important measurement of muscle performance however there are few studies related. The aim of this study was to compare these outcomes between soccer players of different age category. Seventeen professional (PRO) and seventeen under-17 (U17) soccer players were assessed for concentric knee flexion/extension at 60, 120 and 300 °/s. For the extensor muscles, differences were found in favor of the U17 group for TTAV and LR outcomes at 120 °/s, however, the PRO group maintained higher torques in both movement directions in comparison to the U17 in TAV3D evaluation. These results suggest that muscle performance of the PRO group is more efficient than the U17 group
Avaliação de estado nutricional da mangueira Tommy Atkins no submédio do vale do rio São Francisco: estabelecimento das normas DRIS
Este trabalho teve por objetivo estabelecer as
normas do sistema integrado de diagnose e recomendação
(DRIS) para manga, variedade Tommy Atkins. Foram
avaliados sessenta e três pomares comerciais
representativos do Submédio do Vale do Rio São Francisco,
no Nordeste do Brasil. A região não dispõe de um conjunto
de normas de diagnose de tecidos foliares para o cultivo,
sendo o diagnóstico do estado nutricional e as
recomendações de fertilização baseados em faixas de
teores de nutrientes em folhas de mangueira cultivadas em
diferentes regiões. Foram coletadas amostras de folhas
para análise química, antes da aplicação de quebradores de
dormência de brotos. As normas DRIS para nutrição das
plantas foram estabelecidas com base em um banco de
dados criado nesta pesquisa, envolvendo os nutrientes N, P,
K, Ca, Mg, B, Cu, Fe, Mn e Zn. Essas normas foram
estabelecidas considerando uma subpopulação de plantas
com produção igual ou superior a 250 kg/planta, produção
essa representativa para as condições ambientais da
principal zona produtora de manga do país. Das noventa
relações consideradas entre nutrientes, sessenta e duas
foram significativas pelo teste F, das quais, quarenta e
quatro foram selecionadas como normas para a cultura
Avaliação do estado nutricional da mangueira Tommy Atkins no submédio do vale do rio São Francisco: cálculo dos índices DRIS
O Sistema Integrado de Diagnose e
Recomendação, DRIS, é uma ferramenta importante na
avaliação do estado nutricional das plantas. Os objetivos do
presente trabalho foram avaliar o estado nutricional de
pomares de mangueira Tommy Atkins no Submédio do vale
do São Francisco, no Brasil, mediante o DRIS, relacionar os
índices com os teores foliares de nutrientes e discriminar a
ordem de limitação de cada nutriente nas subamostras de
alta e de baixa produtividade. Foram amostrados sessenta
e três pomares comerciais com sete ou mais anos de idade.
Com os teores foliares de macro e micronutrientes foram
calculados os índices DRIS, utilizando-se como referência
os dados da subpopulação de alta produtividade. Os
maiores valores de Índices de Balanço Nutricional médio
(IBNm) verificados em pomares de baixa produtividade
demonstraram o potencial deste índice na avaliação do
estado nutricional da mangueira, e a necessidade de
adubações mais criteriosas em tais pomares. A utilização do
conceito de potencial de resposta à adubação na
interpretação dos índices DRIS mostrou-se uma ferramenta
eficaz, principalmente nos pomares de baixa produtividade,
onde os desequilíbrios nutricionais foram maiores,
confirmando a seqüência de deficiência a excessos,
auxiliando o diagnóstico final, indicando os nutrientes que
realmente estão em deficiência ou em excesso
Feeding strategies and energy to protein ratio on tambaqui performance and physiology
The objective of this work was to evaluate the effect of feed deprivation and refeeding with diets containing different energy to protein ratios (E/P) on the performance and physiology of juvenile tambaqui (Colossoma macropomum). A 4x2 factorial arrangement with three replicates was used, with four E/P ratios (11.5, 10.5, 9.5, and 8.5 kcal g-1 digestible energy per protein) and two feeding regimens (with and without deprivation), during 60 days. Fish from the food-deprived group were fasted for 14 days and refed from the fifteenth to the sixtieth day, whereas the remaining fish were fed for 60 days. At the end of the experimental period, weight of fish subjected to food deprivation was lower than that of those continuously fed; however, this condition did not influence the physiological parameters analyzed. Tambaqui fed 11.5 kcal g-1 achieved lower final weight than those fed with the other diets, in both regimens. Among the physiological parameters, only plasma protein presented significant increase in fish fed 8.5 kcal g-1, in both feeding regimens, probably due to the higher dietary protein concentration. These results indicate that fish show a partial compensatory growth, and that 10.5 kcal g-1 can be recommended for the diet of juvenile tambaqui
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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