1,033 research outputs found

    Developing Advanced Academic Degree Educational Profiles for Career Fields

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    This research develops a career field\u27s educational profile through use of the decision analysis approach of value-focused thinking (VFT). VFT is used to solicit the capabilities that the career field manager (CFM) desires its officers obtain from an advanced academic program. This process generates a value hierarchy and a focused set of alternatives (degree programs). The academic programs\u27 content are evaluated against the hierarchy to determine how well it meets the values of the functional area. A rankordered list of degrees is produced and a portfolio of degrees is selected through the use of CFM-approved goal-setting criteria. The specific breakdown of the portfolio into percentages of the force that should attain each degree is then determined through the CFM\u27s specified relative value increments of the goal-setting criteria. The resulting effort creates a guide for CFMs to communicate to their corps on the types of degrees to earn and provides justification for fully-funded degree slots

    Isokinetic Dynamometry and 1RM Tests Produce Conflicting Results for Assessing Alterations in Muscle Strength

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    The purpose of this study was to compare strength gains in the lower limbs, assessed by one maximum repetition (1RM) and isokinetic peak torque (PT), in young men undergoing a resistance training (RT) program. Twenty-seven young men performed resistance training twice a week for 11 weeks. Training involved two exercises for the lower body, two for the upper body and one for the midsection performed with three sets of 8-12 repetitions to momentary muscle failure. Before and after the training period, participants performed the 1RM test in the 45° leg press and knee extension PT in isokinetic dynamometry. The Pearson correlation coefficient was used to assess the relationship between the changes in 1RM and PT, and the Bland-Altman test was performed to check for agreement between the strength changes of both tests. There were significant changes in 1RM and PT of 23.98% and 15.96%, respectively (p \u3c 0.05). The changes in leg press 1RM were significantly higher than the ones in PT. The Bland-Altman analysis revealed that the tests were not equivalent. In conclusion, professionals and researchers involved in strength assessment should be aware that the results obtained by PT and 1RM are not equivalent when evaluating individual responsiveness and/or the efficacy of an intervention on muscle strength, as the results obtained show large variations and can be even conflicting

    Study of the effect of friction between the ossicles of the middle ear

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    The human ear is a complex biomechanical system and is divided by three parts: outer, middle and inner ear. The middle ear is formed by three ossicles (malleus, incus and stapes), ligaments, muscles and tendons, that amplify the sound, sending the sound waves to the inner ear. In this work, a finite element modelling of the middle ear and ligaments was made. The connection between ossicles was achieved using contact formulation. The modelling of ligaments was based in a hyperelastic model. Studies based in the displacement field of the eardrum and footplate were made, as well as the rotation of the footplate. The stress field in the ligaments to the exterior of the ossicular chain was still analyzed. These studies were done for different friction rates, between the ossicles, and for different acoustic pressure values applied in the eardrum. We can conclude that the connection between the ossicles may be assigned by contact formulation including friction. For simulation proposes, we can assume a quasi-rigid connection between ossicles.Peer Reviewe

    Dribble Deficit enables measurement of dribbling speed independent of sprinting speed in collegiate, male, basketball players

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    Ramirez-Campillo, R, Gentil, P, Moran, J, Dalbo, VJ, and Scanlan, AT. Dribble Deficit enables measurement of dribbling speed independent of sprinting speed in collegiate, male, basketball players. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to determine the relationships between sprinting and dribbling speed in basketball during linear and change-of-direction (COD) sprints using total dribbling time and Dribble Deficit. Collegiate, male, basketball players (n = 10; 21.0 ± 1.6 years) performed linear and COD sprints with and without dribbling a ball. Linear dribbling sprints were measured for the dominant and nondominant hands, whereas COD dribbling sprints involved bilateral use of hands. Dribble Deficit was determined as the difference between total time (second) during each dribbling trial and the equivalent nondribbling trial for linear and COD sprints. Simple linear regression analyses were performed during linear and COD sprints to determine the relationship (R) and shared variance (R) between (a) sprinting times and total dribbling times and (b) sprinting times and Dribble Deficit. Large to very large, significant relationships were evident between linear sprinting and dribbling time for dominant (R = 0.86; R = 0.74, p = 0.001) and nondominant hands (R = 0.80; R = 0.65, p = 0.005). Trivial relationships were apparent between linear sprinting time and Dribble Deficit with dominant (R = 0.10; R = 0.01, p = 0.778) and nondominant hands (R = 0.03; R = 0.00, p = 0.940). A very large relationship was evident between COD sprinting and dribbling time (R = 0.91; R = 0.82, p < 0.001), whereas a trivial relationship was observed between COD sprinting time and COD Dribble Deficit (R = -0.23; R = 0.05, p = 0.530). Dribble Deficit eliminates the strong influence of sprinting speed on outcome measures typically seen when using tests predicated on total dribbling time. Consequently, Dribble Deficit may be of added use in basketball test batteries to measure dribbling speed across linear and multidirectional movement paths

    The influence of muscles activation on the dynamical behaviour of the tympano-ossicular system of the middle ear

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    The human ear is a complex biomechanical system and is divided into three parts: outer, middle and inner ear. The middle ear is formed by ossicles (malleus, incus and stapes), ligaments, muscles and tendons, which transfers sound vibrations from the eardrum to the inner ear, linking with mastoid and Eustachian tube. In this work, a finite element modelling of the tympano-ossicular system of the middle ear was developed. A dynamic study based on a structural response to harmonic vibrations, for a sound pressure level (SPL) of 110, 120 and 130 dB SPL applied in the eardrum, is presented. The connection between the ossicles is made using a contact formulation. The model includes the different ligaments considering its hyperelastic behaviour. The activation of the muscles is based on the constitutive model proposed by previous work. The harmonic responses of displacement and pressure obtained on the stapes footplate, for a frequency range between 100 Hz and 10 kHz, are obtained simulating the muscle activation. The results are compared considering the passive and active states. The results are discussed and they are in accordance with audiological data published with reference to the effects of the middle ear muscles contraction

    Study of the middle ear behavior considering the presence of fluid

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    O objetivo deste trabalho foi estudar a influência de diferentes fluidos dentro e fora da cavidade timpânica no comportamento biomecânico do ouvido médio. O modelo computacional 3 D da cadeia tímpano‐ossicular foi construído através de imagens de tomografia axial computorizada (TAC). Após a construção do modelo da cadeia tímpano‐ossicular, para a parte interna da membrana timpânica foi criada a caixa timpânica, que inclui toda a cadeia ossicular, e para a parte externa da membrana foi criada uma passagem, simulando o canal auditivo externo. A discretização do modelo foi feita utilizando o método dos elementos finitos, com base no software ABAQUS. As propriedades mecânicas foram extraídas de trabalhos anteriores. Foram obtidos os deslocamentos do umbo e de um ponto central da platina do estribo, para um nível de pressão sonora de 105 dB aplicada na membrana timpânica, comparando a cadeia tímpano‐ossicular e os diferentes níveis de pressão externa e interna do ouvido médio (fluido líquido e fluido gasoso). Os resultados demonstram que o comportamento biomecânico do ouvido médio é diferente para os diferentes níveis de pressões testadas neste modelo. Quando utilizada uma pressão de fluido líquido, os deslocamentos são de amplitude inferior quando comparados com os resultados obtidos com pressão de ar.The objective of this work is to study the influence of different fluids of the tympanic cavity into the biomechanical behavior of the middle ear. The 3 D computer model of the tympanic ossicular chain was built using images from computed tomography (CT). After construction of the tympanic ossicular chain model, it was adapted the simulation by placing the passage to the external auditory canal and to the tympanic cavity. The discretization of the model was made using the finite element method based on ABAQUS software. The mechanical properties were extracted from previous works. The umbo and the stapes footplate displacements, for a sound pressure level of 105 dB applied in tympanic membrane were obtained, comparing the tympanic ossicular chain and the different levels of external and internal pressure in the middle ear (liquid and air). The results demonstrate that the biomechanical behavior of the middle ear is different for different levels of pressure tested in this model. When using liquid, displacements are of lower amplitude when compared with the results obtained with air.Peer Reviewe
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