937 resultados para Last two millennia


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The effects of temperature on the rate of biological processes such as the germination are reported in several papers. The analysis of the thermal effect can be performed either from numerical indices or germination curves, which is usually presented as the accumulated percentage of germination versus time. Such curves can be fitted by empirical models and generally they offer a better description of the time-course of germination than single-value indices. On the other hand, in analyzing the germination curves, a question arises whether the model parameters have biological meaning. Thus, it is desirable that the model parameters both describe properly the germination curve and have biological meaning, which often does not occur. Considering the involvement of populations and percentages in germination assays, an analytical model has been widely used in the last two decades which is based on the concept of thermal time. This article discusses the conceptual basis and provides procedures for applying the thermal-time model in germination studies by using the probit regression method, both at infra and supra-optimal temperatures.

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By remote sensing, geodatabase digital processing, information and expeditions to Capivara's sub-basin, was possible to identify the changes in the landscape mainly the expansion of eucalyptus, sugar-cane, and orange trees, being the last two, mainly on the Periferic Depression of Basaltic Cuesta. A significant portion of the soil on this geological area is formed from sandstones, providing high permeability to them, making them important places to groundwater recharge areas as sensible to contamination by pesticides. Throughout last decade was observed that the native vegetation fragments stabilization, keeping a reason of 26.5% on the land used between 2000 and 2010. The pasture decrease being substituted by eucalyptus, sugar-cane and orange trees call attention for the changes in the agribusiness model demanded by the current economic and social necessity. Pasture decrease followed by erosions decrease on sub-basin is evidence that these two aspects are strongly related.

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Proprioceptive neuromuscular facilitation (PNF) is an attractive method to increase strength and proprioception of elderly individuals. However, a major clinical concern about the prescription of PNF is the belief that it can cause a cardiovascular overload, because it involves close-to-maximal loads and isometric contractions. Yet the acute effect of a PNF training session on cardiovascular response in elderly individuals is still unknown. Hence, the objective of this study was to evaluate the effect of PNF on diastolic and systolic blood pressure of healthy elderly people. Fifteen older women (mean age 72.40±6.82 years) performed three sets (five repetitions each) of three different PNF techniques (rhythmic initiation, dynamic reversion, and isotonic combination), executing a single movement pattern. Diastolic and systolic blood pressure (DBP and SBP) were evaluated by means of a manual sphygmomanometer immediately before and during the last two repetitions (last set) of each technique. A two-way ANOVA test (time and technique) was performed to investigate the PNF effect on blood pressure. No time (preexercise to postexercise) (p=0.33 for DBP; p=0.06 for SBP) or PNF technique (p=0.75; p=0.81) effect were observed. In conclusion, we can state that the execution of these PNF techniques is safe for the cardiovascular system of healthy elderly women, because no blood pressure increases were found. Copyright © Informa Healthcare USA, Inc.

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Objectives. One of the concerns of Sports Sciences is the search for methodologies that can help discover potential athletes. In this sense, some initiatives have been taken in an attempt to identify and characterize the genetic profile of dermatoglyphic marks (fingerprints). The present work has the objective of understanding the distribution of quantitative dermatoglyphic indicators in basketball players with different levels of performance compared to non-players. Methods. The subjects observed constituted 125 individuals, divided into five numerically equal groups, three of which were composed of professional basketball players according to their level of participation (Brazilian Team, National Championship and São Paulo Championship) and the last two formed by weekend players and non-players, respectively. Eleven dermatoglyphic variables were analysed in the descriptive level by means of measurement of position, variability and limits of confidence of the median, and, in inferential terms, the Kruskal-Wallis statistical test was adopted. Results. The more expressive ones were: TRC, counting lines a-b and A'-d, behave differently between athletes and non-athletes. Conclusion. Studies about this kind of analysis should be continued, calling on resources that take into consideration all variables simultaneously as a multivariate study. © 2012 Revista Andaluza de Medicina del Deporte.

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Insecticide potential and efficaciousness of vegetal extracts concentrations from six botanic families in three different modes were analyzed on the nymphs of the silverleaf whitefly Bemisia tabaci (Genn. 1889) on a tomato plantation Lycopersicon esculentum Mill. Nymph breeding was kept in cherry tomato shrubs. Test solutions were obtained from successive extractions with ethanol and evaporation in a rotary evaporator. Tests consisted of 10 solutions in four concentrations (500; 1,000; 1,500 and 3,000 μg/mL) and control treatment (distilled water + 1% DMSO) under three different modes of activity, namely, contact, translaminar and systemic. Experimental design was totally randomized with four repetitions and eleven treatments. Means were compared by Scott-Knott test at 5% probability and lethal concentrations (CL50) were calculated by POLO. In the case of contact activity mode, all extracts had efficiency above 50% with the highest concentration (3,000 μg/mL) in which the highest efficiency for all extracts tested was verified. There was a need for dose increase in translaminar activity mode for similar results, whereas in the case of systemic activity the best performance was obtained with extracts of Nerium oleander, Derris amazonica and Ipomoea carnea. Extracts of the last two caused a higher percentage when compared with that of other extracts in all activity modes lower than CL50.

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Pós-graduação em Artes - IA