Analytical studies of sponges have recently become a matter of interest, since these organisms have been reported to accumulate high levels of some elements, including heavy metals, which may have an anthropogenic origin, allowing their application as environmental pollution indicators. In the present work, 35 sponges collected in August 1998 at the Berlengas Natural Park were classified and analysed by secondary target energy-dispersive x-ray fluorescence spectrometry (EDXRF). Some major, minor and trace elements could be determined: Al, Si, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Zr, I and Pb. To assess some local influences on the sponge composition, two sediment samples were also taken from the area and analysed. Besides these elements, sponges are constituted by fairly high percentages of elements that do not emit characteristic x-ray lines. Therefore, absorption corrections for quantitative calculations were carried out taking into account the ratio between the inelastic and elastic scattered incident radiation from a silver secondary target to calculate the mean atomic number of the light matrix. Calibration was performed using chemical compounds and standard reference materials. Precision, accuracy and detection limits for the range of elements determined by the method are particularly suitable for the chemical analysis of these organisms. Results for the sediment chemical composition indicated the existence of high Ca and low Si levels and confirmed the absence of any trace metal contamination in the region. The sponge composition showed low Si contents, even in siliceous specimens. Certain high elemental contents determined in some species indicated a clear selective bioaccumulation of particular trace elements, such as Ni, Zn and As, which is not dependent on local influences.
In breaststroke races, the dolphin kick could finish before, at the same time, or during the arm pull-out, but it is unclear how swimmers perform this technique. The aim of this study was to investigate whether swimmers glide between the dolphin kick and arm pull-out, favour continuity or even overlap those two phases, as it would impact the active underwater sequence. Fourteen international and national male swimmers performed 100-m breaststroke with all-out effort in a pre-calibrated 25 m swimming pool. A multi-camera system with five underwater and five above water cameras positioned at the side of the pool tracked the head of the swimmers throughout the trial and provided the two-dimensional displacement of the head. Key points of the active underwater sequence were obtained from notational analysis in order to assess the coordination between the dolphin kick and the arm pull-out, the mean speed, the relative time and distance covered by the head. A hierarchical cluster analysis identified three coordination profiles. All swimmers started their dolphin kick before the arm pull-out. However, one swimmer started the arm pull-out before the end of the dolphin kick (i.e. 'superposition' pattern of coordination), seven swimmers started the arm pull-out after the end of the dolphin kick (i.e. 'glide' pattern of coordination), and four swimmers synchronised the beginning of the arm pull-out and the end of the dolphin kick (i.e. 'continuity' pattern of coordination), while two other swimmers mixed two coordination profiles among the start and the three turns. Those different profiles allow achieving similar performance outcome, suggesting individual training regarding the underwater phase.
<p>A atividade física proporciona benefícios para a saúde e qualidade de vida de mulheres idosas. Ainda são escassos os estudos longitudinais em mulheres idosas com duração superior a um ano de prática de exercício físico. Assim o objetivo do estudo foi analisar os efeitos de três anos de treino multicomponente na capacidade funcional de mulheres idosas. Métodos: 51 mulheres (66.7±5.30 anos e 159±0.11cm) participaram ao longo de três anos num programa constituído por períodos de nove meses de treino multicomponente seguidos de três meses de destreino. As avaliações decorreram no início/fim de cada período de treino e destreino. Resultados: No 1º, 2º e 3º ano verificaram-se aumentos estatisticamente significativos em todos os parâmetros da capacidade funcional (<em>p</em><0.05). No entanto, o 2º ano revelou ser o período de treino onde observamos os maiores aumentos nos testes T6M (7.43%), SA (383.33%), AC (40.33%), FA (13.05%) e LS (12.5%) (<em>p</em><0.05). Os testes T6M, LS, FA, AC, SA melhoraram entre 4.17% a 576.60% em todos os períodos de treino e diminuíram entre 3.21% a 85.31% em todos os períodos de destreino. Conclusões: Três anos de treino multicomponente contribuíram para a melhoria da capacidade funcional em mulheres idosas, principalmente no 2º ano de intervenção.</p>
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The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen’s d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.
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