34 research outputs found

    Assembléias de aranhas em manchas de cerrado amplamente separadas no Estado de São Paulo, Brasil

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    Spider Assemblages in widely-separated patches of cerrado in São Paulo State, BrazilAssembléias de aranhas em manchas de cerrado amplamente separadas no Estado de São Paulo, Brasil

    Factorial and response surface designs robust to missing observations

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    Made available in DSpace on 2018-11-26T17:35:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-09-01Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Compound optimum design criteria which allow pure error degrees of freedom may produce designs that break down when even a single run is missing, if the number of experimental units is small. The inclusion, in the compound criteria, of a measure of leverage uniformity is proposed in order to produce designs that are more robust to missing observations. By appropriately choosing the weights of each part of the criterion, robust designs are obtained that are also highly efficient in terms of other properties. Applications to various experimental setups show the advantages of the new methods. (C) 2016 Elsevier B.V. All rights reserved.USP UFSCar, Programa Interinst Posgrad Estat, Sao Carlos, SP, BrazilKings Coll London, Dept Math, London, EnglandUniv Estadual Paulista, Dept Bioestat, IB, Botucatu, SP, BrazilUniv Estadual Paulista, Dept Bioestat, IB, Botucatu, SP, BrazilFAPESP: 2014/01818-

    Avaliação da maturação nuclear in vitro de oócitos de gatas domésticas (Felis catus) pré-púberes e púberes

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    O objetivo do trabalho foi avaliar a taxa de maturação nuclear in vitro de oócitos provenientes de gatas doméstica púbere e pré-púbere. Foram utilizadas 15 fêmeas felinas, 10 púberes e 5 pré-púberes; sendo os oócitos obtidos por aspiração quantificados e classificados. Os oócitos classificados como excelentes e regulares foram reunidos em grupos de 10, em meio de cultura, recobertos em óleo mineral em Placas de Petri siliconizadas e descartáveis. Após permanência em estufa, a 38°C e 5% de CO2 por 48 horas, os oócitos foram submetidos a duas lavagens com solução de hialuronidase a 0,4%, fixados em metanol/acido acético e corados com orceína acética. A avaliação da configuração cromossômica de oócitos maturados in vitro resultou em 44,68% das células em metáfase II no grupo das fêmeas púberes e 25,32% no grupo das doadoras pré-púberes, indicando que a puberdade influencia a capacidade dos oócitos se desenvolverem in vitro.This study assessed the in vitro oocyte nuclear maturation in adult and young domestic cats. Fifteen ovaries were used; 10 from adult females and 5 from young females. The oocytes collected by aspiration were quantified and classified. The oocytes classified as excellent and/or regular were grouped (10 oocyte /drop) in culture medium covered with mineral oil in disposable Petri dishes. The oocyte were incubated at 38°C and 5% de CO2 for 48 hours and then washed with 0,4% hyaluronidase, fixed in methanol/acetic acid and stained with acetic orcein. Evaluation of chromosomal configuration of oocytes matured in vitro showed 44,68% of oocyte in metaphase II in the adult female group and 25,32% in the young donor group, showing that puberty influences oocyte capacity for in vitro development

    Improved split-plot and multi-stratum designs

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    Many industrial experiments involve some factors whose levels are harder to set than others. The best way to deal with these is to plan the experiment carefully as a split-plot, or more generally a multi-stratum, design. Several different approaches for constructing split-plot type response surface designs have been proposed in the literature since 2001, which has allowed experimenters to make better use of their resources by using more efficient designs than the classical balanced ones. One of these approaches, the stratum-by-stratum strategy, has been shown to produce designs that are less efficient than locally D-optimal designs. An improved stratum-by-stratum algorithm is given, which, though more computationally intensive than the old one, makes better use of the advantages of this approach, i.e. it can be used for any structure and does not depend on prior estimates of the variance components. This is shown to be almost as good as the locally optimal designs in terms of their own criteria and more robust across a range of criteria. Supplementary material is available online

    Difference variance dispersion graphs for comparing response surface designs with applications in food technology

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    Variance dispersion graphs have become a popular tool in aiding the choice of a response surface design. Often differences in response from some particular point, such as the expected position of the optimum or standard operating conditions, are more important than the response itself. We describe two examples from food technology. In the first, an experiment was conducted to find the levels of three factors which optimized the yield of valuable products enzymatically synthesized from sugars and to discover how the yield changed as the levels of the factors were changed from the optimum. In the second example, an experiment was conducted on a mixing process for pastry dough to discover how three factors affected a number of properties of the pastry, with a view to using these factors to control the process. We introduce the difference variance dispersion graph (DVDG) to help in the choice of a design in these circumstances. The DVDG for blocked designs is developed and the examples are used to show how the DVDG can be used in practice. In both examples a design was chosen by using the DVDG, as well as other properties, and the experiments were conducted and produced results that were useful to the experimenters. In both cases the conclusions were drawn partly by comparing responses at different points on the response surface

    Some practical advice on polynomial regression analysis from blocked response surface designs

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    It is often necessary to run response surface designs in blocks. In this paper the analysis of data from such experiments, using polynomial regression models, is discussed. The definition and estimation of pure error in blocked designs are considered. It is recommended that pure error is estimated by assuming additive block and treatment effects, as this is more consistent with designs without blocking. The recovery of inter-block information using REML analysis is discussed, although it is shown that it has very little impact if thc design is nearly orthogonally blocked. Finally prediction from blocked designs is considered and it is shown that prediction of many quantities of interest is much simpler than prediction of the response itself
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