9 research outputs found

    EFFECT OF SITE AND COMPETITION ON DIAMETER GROWTH OF Araucaria angustifolia

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    Although the historical interest in using the wood of Araucaria angustifolia, it is still little known concerning the factors that affect the growth. A broader understanding in this context might contribute to the development of appropriate management systems, thus increasing the productivity of plantations and, consequently, the interest in commercially using this species. The present study was based on monospecific populations established in different site conditions (Site Indices between 18-24) where individuals (n=654) were submitted to different competition levels. With the aid of multiple regression techniques, the factors that significantly affected the accumulated growth in diameter of the trees after 20 years of intervention were determined. For the set formed by all trees, 77% of the growth variation can be explained by three factors: site, the proportion of tree diameter at breast height (dbh) of the object tree for analysis in relation to the average dbh of the population before performing the clearings (Cdbh_before) and dominance status in relation to the neighboring trees (Call). The significance of the competition level before the clearing shows that late clearings have limited effects on tree growth. It is concluded that individuals are benefited for having a dominant position in relation to the neighboring trees, reaching diameters 50% larger at the end of the production cycle. Clearings that favour selected trees by removing direct competitors seem to be an interesting management strategy for the species.Keywords: Paraná-pine; Forest Management; Silviculture; Timber Production

    Correlation between morphological characters and estimated bunch weight of the Tropical banana cultivar

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    The objective of this study was to measure and identify the variables that have more influence on bunch weight (BW), and determine a statistical model for predicting yield for the Tropical banana cultivar (cv.). The experiment consisted of a uniformity trial, conducted in Guanambi, Bahia, with a total of 360 plants of the Tropical cultivar YB42-21 (AAAB) in an area of 2,160 m2. The vegetative characteristics such as plant height, pseudostem circumference, number of children (suckers) produced and number of green leaves at flowering and harvest, and yield characteristics such as BW, number of hands and fruits, weight of the second hand, length and diameter of the fruit were assessed in two growing seasons. In the evaluation, each plant was considered as a basic unit with an area of 6 m2, thus, there was a total of 360 basic units. The variables that correlated with the weight of the bunch are: average fruit weight (FW), weight of the rachis, number of fruits per bunch, fruit length (FL) and number of leaves at harvest. The methodology of multiple linear regression (MLR) was used to estimate bunch weight. The most significant variables that were measured included number of leaves at harvest, number of fruits per bunch, FW, FL, rachis weight (RW) and stalk length (SL), generating the following prediction equation: BW= -5.249 + 0.11NLH + 0.066NFB + 0.046FW + 0.183FL + 2.039RW -0.011LS.Key words: Musa spp., production, banana, regression model

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    Alternative for the evaluation of coffee seedlings using Fisher's discriminant analysis

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    ABSTRACT One of the applications of Fisher's linear discriminant function (FDF) is its use in transforming multivariate data into a new univariate variable. This then makes possible a new option for the variance analysis of multivariate data, in addition to the multivariate analysis of variance (MANOVA). The aim of this work was to select groups of seven characteristics of quality in coffee seedlings using six criteria for selection, to use the FDF to transform such groupings of characteristics into a new variable, and then to compare interpretation of the results obtained from the univariate and multivariate analyses of variance of the characteristics and this new variable, with a view to its use in evaluating coffee seedlings. A randomised block design was used to assess the effect of organic fertiliser on the formation of seedlings in coffee cv. Catuaí Vermelho IAC-44, evaluating the following characteristics: seedling height, diameter, root length, dry weight of shoots and roots, leaf area, number of leaves and total dry weight. According to the selection criteria used, different subsets of the selected characteristics are possible. The use of the FDF is shown to be viable in discriminating between treatments. Univariate analysis of the new variable obtained with the FDF and multivariate analysis (MANOVA) was able to detect differences between the treatments, however, it is simpler to apply FDF methodology

    Mobile Application as a Learning Aid for Nurses and Nursing Students to Identify and Care for Stroke Patients

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    Cerebrovascular accident is a serious public health problem and requires the attention of professionals who can detect, diagnose, and provide care in a timely fashion. A quantitative quasi-experimental study was conducted using a mobile app called mSmartAVC for clinical evaluation of nursing care at the bedside. The study aimed at measuring the knowledge of nurses and nursing students in the detection and care of cerebrovascular accident. In this study, a total of 115 nurses from health services in the South of Brazil and 35 nursing students of a community university participated. The stages focused on development, modeling of clinical cases, problem-based learning, pretest (before) app use, and posttest (after) use of the app. The results of the pretest and posttest corrections showed a substantial statistical difference (P < .001), indicating a significant knowledge gain after the use of the app, particularly in terms of the detection scales and interpretation of the imaging tests. The mSmartAVC app used at the bedside supported decision-making for detection and nursing care. It was possible to confirm that the use of mobile apps plays an essential role as a learning tool for nurses and nursing students.info:eu-repo/semantics/publishedVersio

    Ajuste de modelos de platô de resposta via regressão isotônica Response plateau models fitting via isotonic regression

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    Dentro do contexto nutricional, a suplementação de microminerais em rações para aves frequentemente é feita em quantidades superiores às exigidas na tentativa de assegurar o bom desempenho dos animais. Os experimentos do tipo dose resposta são muito comuns na determinação de níveis ótimos dos nutrientes na ração e contemplam a utilização de modelos de regressão para atingir tal objetivo. Porém, na análise de regressão usual, geralmente, não se usa uma informação a priori sobre uma possível relação de ordem na variável resposta. A regressão isotônica é um método de estimação por mínimos quadrados que gera estimativas que satisfazem a mesma ordenação dos dados. Na teoria da regressão isotônica, essa informação é utilizada de forma essencial e espera-se que a eficiência do ajuste seja aumentada quando se faz uso dela. Diante do exposto, o presente trabalho tem como objetivo utilizar uma metodologia de regressão isotônica, como uma forma alternativa para analisar dados de deposição de zinco (Zn) na tíbia de aves machos da linhagem Hubbard. No estudo, foram considerados os modelos de platô de resposta polinomial quadrático e não linear exponencial. Além desses modelos, também foi proposto o ajuste de um modelo logarítmico para os dados e a eficiência da metodologia foi avaliada por meio de um estudo de simulação Monte Carlo, considerando diferentes cenários para os valores paramétricos. A isotonização dos dados propiciou uma melhora em todos os avaliadores de qualidade de ajuste considerados no trabalho. Dentre os modelos utilizados, o logarítmico apresentou estimativas dos parâmetros mais coerentes com os valores relatados na literatura, para os dados de deposição de Zn na tíbia de aves machos.<br>Within the nutritional context, the supplementation of microminerals in bird food is often made in quantities exceeding those required in the attempt to ensure the proper performance of the animals. The experiments of type dosage x response are very common in the determination of levels of nutrients in optimal food balance and include the use of regression models to achieve this objective. Nevertheless, the regression analysis routine, generally, uses a priori information about a possible relationship between the response variable. The isotonic regression is a method of estimation by least squares that generates estimates which preserves data ordering. In the theory of isotonic regression this information is essential and it is expected to increase fitting efficiency. The objective of this work was to use an isotonic regression methodology, as an alternative way of analyzing data of Zn deposition in tibia of male birds of Hubbard lineage. We considered the models of plateau response of polynomial quadratic and linear exponential forms. In addition to these models, we also proposed the fitting of a logarithmic model to the data and the efficiency of the methodology was evaluated by Monte Carlo simulations, considering different scenarios for the parametric values. The isotonization of the data yielded an improvement in all the fitting quality parameters evaluated. Among the models used, the logarithmic presented estimates of the parameters more consistent with the values reported in literature
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