Resumo em português Considerando a crescente utilização da técnica de nado ondulatório submerso (NO SB) durante a saída e as viradas nas provas de nado crawl, o presente estudo objetivou determinar a força dos membros inferiores em nado ondulatório (FMI NO) e suas correlações com as performances máximas do NO SB e na superfície (NO SP). Para isso 19 nadadores com idade de 15,2±0,6 anos filiados a federação aquática paulista foram submetidos a um esforço máximo de 30s de FMI (mais) NO, atados a um dinamômetro contendo células de carga como elemento sensor primário. A tensão detectada pelo dinamômetro, devido aos esforços dos nadadores, foi amplificada por uma fonte de extensometria. Os valores obtidos foram enviados ao computador armazenados na freqüência de 200Hz e suavizados utilizando o filtro "butterworth" de quarta ordem com freqüência de corte de 3 Hz. Com a utilização da reta de calibração pode-se converter valores de tensão (mV) em unidades de força (N) pelo programa Matlab 5.3, possibilitando assim a determinação dos valores médios de FMI NO. Posteriormente os nadadores realizaram esforços máximos de 15 m de NO SB e de 25 m NO SP. As possíveis relações entre esses três esforços, foram analisadas utilizando o teste de correlação de Pearson com nível de significância pré-fixado para P Resumo em inglês Considering the crescent utilization of the underwater dolphin kick (NO SB) techniques during the beginning and the turns of front crawl events, the main purpose of the present study was to determine the dolphin kick force (FMI NO) in tethered swimming and its correlations with the maximal performance determined in NO SB and in dolphin kick with a commercial board (NO SP). Nineteen male swimmers with mean age of 15.2±0.6 years and affiliated with Sao Paulo Aquatic Federa (mais) tion participated in the present study. The athletes were submitted a 30-s maximal effort of dolphin kick tethered to a dynamometer with strain gages (load cells) as a primary sensor element. The tension detected by the dynamometer due the swimmers efforts was amplified by an extensometer font. The results obtained during the efforts were sent to a computer using an interface and were stored in a data acquisition program at 200 Hz. After these procedures, the results were smoothed using the "butterworth" filter of fourth order with 3-Hz frequency. Using the calibration straight line, the values were converted into force units (N) by the Matlab 5.3 program. This conversion allowed the determination of the dolphin kick mean force in tethered swimming (FMI NO). Then, the swimmers performed a 15-m maximum effort of underwater dolphin kick (NO SB) and another 25-m maximum effort of dolphin kick using a commercial board (NO SP). The relationships between these three maximum efforts were analyzed using the Pearsons correlation coefficient. A significance level of 5% was chosen. The mean ± standard deviation of FMI NO, NO SB and NO SP were 53.85 ± 11.45N, 1.19 ± 0.14 m.s-1, and 1.76 ± 0.26 m.s-1, respectively. The FMI NO presented significant correlations with NO SB(r= 0.80) and NO SP (r= 0.76). According to the results of the present study, the use of FMI NO to evaluate and predict the NO SB and NO SP of experts swimmers is suggested. However, more studies are necessary to verify the sensibility of the FMI NO to specific effects into the swimming training.
Resumo em inglês Besults are presented of mineral fertilizer trials witht Irish potato crop in the State of São Paulo. The experiments were conducted in the flat lands of the Paraíba River banks. In this region, potato plantings are usually made from May to October, a period with little rain, :nul practically free from flood. From October to April, when good weather conditions prevail, rice is almost the only crop grown. Iu other regions of the State, potato is planted in February or in (mais) August. Chemical analyses of an average sample of the soil revealed a high organic matter content, about seven fold higher total nitrogen content and a twelve fold higher total carbon content, as compared with those found in a soil sample taken from Capão Bonito, an important potato area in the State, where phosphoric acid has been found to be responsible for increases in tuber productions. The experimental design was arranged so that conclusions could be drawn from the influence of increasing amounts of each nutrient element N, P and K, in the presence of a constant amount of the other two. In spite of the high total nitrogen content of the soil, results have shown this element not to he in available form for plants. In these experiments, application of nitrogen has been found to be effective and even decisive in increasing tuber yield. Lack of this element results in a lower production, in some cases, even inferior to check plots. In experiment n.° 38, for instance, PK yielded two tons of tubers per hectar, whereas NK and NP yielded, respectively, 1.1.9 and 12.4 tons. In another trial, n.° 40 BK yielded 10.5 tons per hectar (less than check), while NPK yielded 16.2 tons. From the economical point of view, an amount of 80 kg of N to the hectar in the presence of PK, brougth better profits, application of PK alone, resulted in losses. Determinations of starch content in tubers of every treatment have shown no appreciable differences between them.