KINEMATICAL AND DYNAMICAL ANALYSIS OF LONG JUMP TAKE-OFF: A FOUR CASES STUDY

INTRODUCTION-The take-off is one of. the most important phases of the long jump. Once there is no available knowledge on kinematic vs. dynamic relationships on the take-of, the purposes of this study were: (i) to analyse the biomechanical variations that occur at take-off; (ii) to establish relationships between kinematic and dynamic variables; (iii) to verify which of the moments of the take-off is more important to the production of the vertical velocity as well as the best result. METHODS~ Subjects for this 4-casesstudy research were well trained jumpers. Each athlete performed 6 trials, all videotaped (JVC-SVHS) in the sagitai plane for kinematical analysis (50 Hz). Simultaneously, dynamic analysis was performed through a Kistler 9218 B force plate (250 Hz). The kinematic parameters studied were: (i) resulting velocity of the center mass (VCM); (ii) horizontal velocity of the center mass (Vx); (iii) vertical velocity of the center mass (Vy); (iv) horizontal velocity of the lead leg knee (VeIK); (v) horizontal velocity of the touchdown foot (VeITd); (vi) loss of horizontal velocity (LVx); (vii) gain of vertical velocity (GVy); (viii) center mass / heel angle in the instants of touchdown and take-off (AngCM-he); (ix) knee angle (AngK); (x) support time (ST); (xi) touchdown distance (TdD); (xii) take-off angle (AngT). The described velocities and angles were determined in the following instants: (i) touchdown; (ii) maximum knee flexion and (iii) take off. The dynamical parameters studied were: fi) vertical impulse (Iz): (ii) maximum vertical force (Fzmax): (iii) time course to achieve maximum vertical force (lH/Fz max); (iv) passive impulse (lzPass}: (v) time course of the passive impulse (lHPass); (vi) active impulse (lzAct); (vii) time course of the active impulse (ßTAct); (viii) horizontal anterior posterior impulse (Iy); (ix) horizontal lateral impulse (Ix) RESULTS-The main results of this study showed that, in all cases, the major loss of the Vx and the major gain of the Vy were observed between the touchdown and the maximum knee flexion We also noticed that the knee of the lead leg has its maximum velocity at the moment of the maximum knee flexion for all subjects. This variables contribute significantly, in all cases, to the increase of the AngK in the take-off instant (psO.05), which is theoretically advantageous to the performance. One other finding was that when the values for AngCM-he in the touchdown and take-off instants were out of the theoretical limits defined by Fischer (1975), a reduced performance was observed. The observation of results also showed: (i) a increased Fzmax was always related with a higher jump length, with a higher % IZPass / IzAct, with a reduction both on ßTAct and ST, despite the correlation analysis did not always provide significant r values. CONCLUSIONS-Long jumpers should pay a special attention to the phase between the touchdown and the maximum knee flexion, where the main production of Vy occurs. There, a reduclion on ST during the take-off should be searched. Attention should also be paid to the values of the AngCM-he during the touchdown. REFERENCES Fischer, R. (1975). Weitsprung. Biomechanische untersuchungen am schweizerischen weitsprungkader mittels filmanalyse und messugen mir der mehrkomponenrenmessplattform. Diplamarbeil in biomechanik, ETH, Zurich

Caracterização de produtores de uva de mesa e dos sistemas de irrigação da região de Jales (SP).

O objetivo do presente trabalho é caracterizar, com base em dados amostrais, as propriedades da região e os sistemas de irrigação que são utilizados na cultura da videira.bitstream/item/48529/1/ComunicadoTecnico-106.pd

Crescimento do coqueiro jovem no nordeste de São Paulo.

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INTEGRATED KINEMATIC AND DYNAMIC ANALYSIS OF TWO TRACK-START TECHNIQUES

The purpose of this research was to characterise and compare two variants of the trackstart technique for ventral swimming races, using simultaneous and synchronised dynamic and kinematic data. Results indicated that the track-start variant with rear projection of the centre of gravity (TSR) is able to produce higher impulses and velocities, but also implies higher periods in the starting block and presumably higher hydrodynamic drag values during entry, that imposes identical total times for the first 6m of the race, when compared with the track-start technique with forward projection of the centre of gravity (TSF)

Germinação da semente e desenvolvimento da plântula de coqueiro anão verde no Nordeste de São Paulo.

Avalia o comportamento germinativo da semente e o desenvolvimento da plântula de coqueiro Anão, em condições definidas.bitstream/item/79800/1/CPATC-COM.-TEC.-12-97.pd

Efeito da cobertura de tela e do dossel da cultura na radiação solar incidente em videiras.

A região de Jales é uma das principais produtoras de uvas de mesa do Estado de São Paulo, Brasil. A cultura da videira na região é conduzida, normalmente, no sistema de latada e coberta com tela plástica para a proteção contra a ocorrência de granizo e o ataque de morcegos e pássaros. O presente trabalho teve como objetivo determinar o efeito do uso da tela e do dossel da cultura nos valores da radiação solar global incidente. As avaliações foram realizadas na Estação Experimental de Viticultura Tropical da Embrapa Uva e Vinho, em Jales, SP (20°16´S, 50°33´W e 483 m), utilizando-se uma parreira coberta com tela plástica de polietileno com sombreamento nominal de 18%. Foram empregados dois piranômetros. sendo um instalado a céu aberto e outro no interior da parreira, conectados a dois sistemas automáticos de aquisição de dados, com registros efetuados a cada 15 minutos. Os valores da radiação solar global sob a tela plástica (Rst) foram, em média, 20% menores dos observados a céu aberto (Rsc), valor semelhante ao sombreamento nominal apresentado pela tela (18%). A radiação solar global abaixo do dossel da cultura (Rsd). variou de 68% da Rsc, logo após a poda, até 19% da Rsc,. no período da colheita. A redução da radiação solar incidente devido ao uso de tela plástica e ao sistema de condução adotado na região pode afetar, diretamente, as taxas do transpiração e fotossíntese e a evaporação da água livre das folhas e frutos.Editado por: Celito Crivellaro Guerra e Sandra de Souza Sebben. Na capa: CONGRESSO BRASILEIRO DE VITICULTURA E ENOLOGIA, 11.; SEMINÁRIO FRANCO-BRASILEIRO DE VITICULTURA E ENOLOGIA, 2. Bento Gonçalves, 2005

A conserved dimorphism-regulating histidine kinase controls the dimorphic switching in Paracoccidioides brasiliensis

Paracoccidioides brasiliensis and P. lutzii, thermally dimorphic fungi, are the causative agents of paracoccidioidomycosis (PCM). Paracoccidioides infection occurs when conidia or mycelium fragments are inhaled by the host, which causes the Paracoccidioides cells to transition to the yeast form. The development of disease requires conidia inside the host alveoli to differentiate into yeast cells in a temperature-dependent manner. We describe the presence of a two-component signal transduction system in P. brasiliensis, which we investigated by expression analysis of a hypothetical protein gene (PADG_07579) that showed high similarity with the dimorphism-regulating histidine kinase (DRK1) gene of Blastomyces dermatitidis and Histoplasma capsulatum. This gene was sensitive to environmental redox changes, which was demonstrated by a dose-dependent decrease in transcript levels after peroxide stimulation and a subtler decrease in transcript levels after NO stimulation. Furthermore, the higher PbDRK1 levels after treatment with increasing NaCl concentrations suggest that this histidine kinase can play a role as osmosensing. In the mycelium-yeast (M -> Y) transition, PbDRK1 mRNA expression increased 14-fold after 24 h incubation at 37A degrees C, consistent with similar observations in other virulent fungi. These results demonstrate that the PbDRK1 gene is differentially expressed during the dimorphic M -> Y transition. Finally, when P. brasiliensis mycelium cells were exposed to a histidine kinase inhibitor and incubated at 37A degrees C, there was a delay in the dimorphic M -> Y transition, suggesting that histidine kinases could be targets of interest for PCM therapy.CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Brazil)FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo/Brazil)Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Unidade Jose Alencar, St Sao Nicolau 210,4 Floor, BR-04023900 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Farmaceut, R Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilUniv Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Unidade Jose Alencar, St Sao Nicolau 210,4 Floor, BR-04023900 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Farmaceut, R Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilCNPq: 478023/2013-8FAPESP: 2014/13961-1FAPESP: 2015/09727-6Web of Scienc

Saharan dust electrification perceived by a triangle of atmospheric electricity stations in Southern Portugal

Atmospheric Electric Potential Gradient (PG) measurements were carried out in three sites forming a triangular array in Southern Portugal. The campaign was performed during the summer, characterized by Saharan dust outbreaks; 16th-17th July 2014 dust event is considered. Short time-scale oscillations of the PG at two of the stations and a mid time-scale suppression of the PG in the three stations are found. Results are interpreted as evidencing long-range dust electrification; attributed to the air-Earth electrical current creating a bipolar charge distribution inside of the dust layer. The relevance of using arrays of sensors, instead of single sited, is highlighted