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Novo método para sele o de dispersantes de última gera o para concretos refratários  [cached]
Pardo A. R. F.,Pileggi R. G.,Pandolfelli V. C.
Ceramica , 2002,
Abstract: O aprimoramento dos processos de instala o de concretos refratários (auto-escoamento, bombeamento, proje o, etc.) tem intensificado a necessidade de otimiza o e controle do comportamento reológico destes materiais. A distribui o granulométrica e a concentra o de sólidos, além da natureza das matérias-primas e dos aditivos químicos presentes no sistema, s o os principais fatores que determinam sua reologia. Em conseqüência, a correta escolha dos agentes dispersantes é uma das tarefas fundamentais para o desenvolvimento sistemático de concretos. Contudo, os critérios tradicionalmente empregados para esta sele o, os quais se baseiam no ensaio de fluidez ou na caracteriza o reológica da matriz, n o avaliam o comportamento do material frente às solicita es diversas de seu processamento e de sua aplica o. Sendo assim, neste trabalho foi proposto um novo método para avalia o e sele o de dispersantes, o qual analisa o comportamento do concreto desde a etapa de mistura até seu fluxo sob cisalhamento intenso. Dois aditivos usualmente empregados em concretos de alta alumina, polimetacrilato de sódio e ácido cítrico, além de dois novos dispersantes de última gera o, foram ent o avaliados pelo método proposto e pela tradicional fluidez. Os resultados demonstraram a eficiência da nova técnica, além de atestarem o superior desempenho dos novos dispersantes avaliados.
Sele o de variáveis para classifica o de bateladas produtivas com base em múltiplos critérios A multiple criteria-based method for variable selection in industrial applications  [cached]
Michel José Anzanello
Produ??o , 2013,
Abstract: Processos industriais s o frequentemente descritos por um elevado número de variáveis correlacionadas e ruidosas. Este artigo apresenta um método para sele o das variáveis mais relevantes para classifica o de bateladas de produ o valendo-se de múltiplos critérios de desempenho (sensibilidade e especificidade). As bateladas s o categorizadas em duas classes (conforme ou n o conforme, por exemplo). O método utiliza a regress o PLS (Partial Least Squares) para derivar um índice de importancia das variáveis de processo. Um procedimento iterativo de classifica o das bateladas e elimina o das variáveis é ent o conduzido. Por fim, uma medida de distancia euclidiana ponderada é aplicada para selecionar o melhor subconjunto de variáveis. Ao ser aplicado em dados de processos industriais, o método proposto reteve, em média, 12% das variáveis originais, elevando a sensibilidade em 9%, de 0,78 para 0,85, e a especificidade em 20%, de 0,64 para 0,77. Estudos de simula o permitiram avaliar o desempenho do método frente a cenários distintos. Several correlated and noisy variable are collected from industrial processes. This paper proposes a method for selecting the most relevant process variables aimed at classifying production batches into classes based on multiple criteria (e.g., sensibility and specificity). Production batches are inserted into two classes. The method first applies the PLS regression (Partial Least Squares) on process data and derives a variable importance index. A classification/elimination procedure is then carried out, and a weighted Euclidian distance is generated to identify the recommended variable subset. When applied to the testing set of real industrial data, the proposed method retained average 12% of original variables. The recommended subsets yielded 9% higher sensibility, from 0.78 to 0.85, and 20% higher specificity, from 0.64 to 0.77. Simulation experiments are also performed.
Avalia??o e sele??o de progênies resultantes do cruzamento de cultivares de café Catuaí com Mundo Novo
Carvalho, Gladyston Rodrigues;Mendes, Ant?nio Nazareno Guimar?es;Bartholo, Gabriel Ferreira;Amaral, Mário Aparecido;
Ciência e Agrotecnologia , 2006, DOI: 10.1590/S1413-70542006000500004
Abstract: the objective of this paper was to select coffee progenies from the crosses of 'catuaí' with 'mundo novo', the most productives and adapted to different environment. in this experiment twelve progenies were selected, in the fourth generation for the second self-backcrossing of the catuaí and mundo novo, developed by empresa de pesquisa agropecuária de minas gerais, coffee breeding program. the coffee cultivars catuaí vermelho iac-99, rubi mg 1192 and acaiá cerrado mg 1474 were also as control. the experiments were conducted in s?o sebasti?o do paraíso and três pontas in minas gerais using the randomized block design, with four replicates and six plants per plot. there were evaluated the production based in the 60 kg bag of processed coffee/ha. the variance analysis was realized with split plot where each harvest (year) was considered as one split plot. the production data by place was analysed together, considering all the harvest. the treatment means were compared by scott-knott test, at 5% of probability. the results obtained showed that the best progenies were h 1190-11-70-2, 1190-11-119-1, 1190-11-70-1 and 1190-11-8-2 and the progenies h 1190-11 -70-1 and 1190-11-8-2 had the highest adaptability on two environments.
Stellar population models of Lick indices with variable element abundance ratios  [PDF]
Daniel Thomas,Claudia Maraston,Ralf Bender
Physics , 2002, DOI: 10.1046/j.1365-8711.2003.06248.x
Abstract: We provide the whole set of Lick indices from CN1 to TiO2 of Simple Stellar Population models with, for the first time, variable element abundance ratios, [alpha/Fe]=0.0, 0.3, 0.5, [alpha/Ca]=-0.1, 0.0, 0.2, 0.5, and [alpha/N]=-0.5, 0.0. The models cover ages between 1 and 15 Gyr, metallicities between 1/200 and 3.5 solar. Our models are free from the intrinsic alpha/Fe bias that was imposed by the Milky Way template stars up to now, hence they reflect well-defined alpha/Fe ratios at all metallicities. The models are calibrated with Milky Way globular clusters for which metallicities and alpha/Fe ratios are known from independent spectroscopy of individual stars. The metallicities that we derive from the Lick indices Mgb and Fe5270 are in excellent agreement with the metallicity scale by Zinn & West (1984), and we show that the latter provides total metallicity rather than iron abundance. We can reproduce the relatively strong CN-absorption features CN1 and CN2 of galactic globular clusters with models in which nitrogen is enhanced by a factor three. An enhancement of carbon, instead, would lead to serious inconsistencies with the indices Mg1 and C24668. The calcium sensitive index Ca4227 of globular clusters is well matched by our models with [Ca/Fe]= 0.3, including the metal-rich Bulge clusters NGC 6528 and NGC 6553. From our alpha/Fe enhanced models we infer that the index [MgFe] defined by Gonzalez (1993) is quite independent of alpha/Fe, but still slightly decreases with increasing alpha/Fe. We define a slight modification of this index that is completely independent of alpha/Fe and serves best as a tracer of total metallicity. Searching for blue indices that give similar information as Mgb and Fe, we find that CN1 and Fe4383 may be best suited to estimate alpha/Fe ratios of objects at redshifts z~1. (Abridged)
Sele o gen mica ampla (GWS) e maximiza o da eficiência do melhoramento genético Genome wide selection (GWS) and maximization of the genetic improvement efficiency
Marcos Deon Vilela de Resende,Paulo Sávio Lopes,Rogério Luíz da Silva,Ismael Eleotério Pires
Pesquisa Florestal Brasileira , 2010, DOI: 10.4336/2012.pfb.56.63
Abstract: A sele o genética tem sido praticada pelo procedimento BLUP, usando dados fenotípicos avaliados a campo. Uma primeira proposi o realizada para aumentar a eficiência desse procedimento, baseado em dados fenotípicos, foi a sele o auxiliada por marcadores (MAS) moleculares, a qual usa simultaneamente dados fenotípicos e moleculares. Posteriormente, foi proposto um novo método de sele o denominado sele o gen mica ampla (genome wide selection – GWS), o qual apresenta alta acurácia seletiva para a sele o, baseada exclusivamente em marcadores, após terem seus efeitos genéticos estimados a partir de dados fenotípicos em uma amostra da popula o de sele o. A GWS é excelente para caracteres de baixa herdabilidade, ao contrário da MAS, que n o é útil para caracteres de baixa herdabilidade. O presente trabalho tem como objetivos apresentar a metodologia GWS e simular um caso de aplica o da mesma, visando enfatizar as suas vantagens sobre a MAS. Objetiva também demonstrar a rela o entre o BLUP tradicional e o BLUP gen mico associado à GWS. Adicionalmente, discute aspectos referentes ao tamanho amostral adequado para estima o dos efeitos genotípicos dos marcadores. Os resultados revelam que a GWS poderá ter grande utilidade ao melhoramento genético. No entanto, é preciso adquirir experiência prática com a GWS, visando inferir sobre sua efetividade. Genetic selection has been practiced by the best linear unbiased prediction (BLUP) method using phenotypic records. A first proposal for enhancement of the efficiency of this procedure was the marker assisted selection (MAS). Later, another method called genome wide selection - GWS was reported, which presents high accuracy for the selection based exclusively on markers, after predicting their genetic effects from phenotypic data in a sample of the population of selection. GWS is excellent for low heritable traits, while MAS is not. This paper presents the GWS methodology and simulates a case of its application, aiming at emphasizing its advantages over MAS. The relation between traditional BLUP and genomic BLUP is also detailed as well as the sample size required for precise estimation of the genetic values of the markers. Results revealed that the GWS can be worthy for genetic improvement. Practical experience is much needed to infer about its effectiveness.
Melhoramento do cafeeiro: X - Sele??o visando eliminar o defeito "lojas vazias do fruto" no café Mundo Novo
Carvalho, A.;Antunes Filho, H.;
Bragantia , 1955, DOI: 10.1590/S0006-87051955000100006
Abstract: a high proportion of plants of the mundo novo coffee (a strain of coffea arabica l. var. bourbon (b. rodr.) choussy) produce an abnormally large number of fruits with empty locules. since this character reduces the rate of coffee beans per weight of fruit, selection was started aiming at reducing or eliminating plants having this defect, and thereby increasing the yeild of coffee beans. preliminary investigations carried out in 1950 on the occurrence of empty locules in selfed progenies and hybrids of the bourbon plant no. 44, which presents a high percentage of this defect, indicated that this characteristic was heritable. it was also determined that only normal plants were found in progenies of normal individuals, even when these belonged to progenies in which some of the sibs produced large number of fruits with empty locules. based on this information, seeds from normal, high yielding plants of mundo novo coffee were released to coffee growers in 1950. in one of the first farms to use selected seeds of mundo novo coffee, approximately 7,000 trees (one tree is really a group of four plants in the same hill) were planted with seeds produced by the best plants of five of the most outstanding progenies of this variety. a small crop was available in 1953. due to the increasing demand for selected seeds of mundo novo coffee, it was then suggested that the state extension service buy the seeds produced in this farm and distribute them to coffee growers that were willing to plant them for seed production. before this suggestion was put into effect, the whole planting was surveyed for the presence of plants producing large numbers of fruits with empty locules. by means of a sampling technique, it was determined that only from 2 to 7 per cent of abnormal plants were found in the plantation. when these numbers were contrasted with the 50 per cent index of undesirable trees normally found in the original mundo novo plantings, it became evident that selection to eliminate pl
Eficiências relativas de métodos de sele o de famílias endogamicas em milho-pipoca = Relative efficiencies of selection methods of inbred families in popcorn
Emmanuel Arnhold,José Marcelo Soriano Viana,Ricardo Gon?alves Silva,Freddy Mora
Acta Scientiarum : Agronomy , 2009,
Abstract: Objetivou-se avaliar a eficiência relativa da sele o massal, entre e dentro e de um novo índice de sele o combinada proposto. O índice, baseado na genealogia, foi obtido por: IC = b1 PSn-1 + b2PFSn , em que PSn-1 é o valor fenotípico da planta Sn – 1; PFSn é o valor fenotípico da família Sn descendente da planta Sn – 1; b1 é o peso do valor fenotípico individual; e b2 é o peso do valor fenotípico de família Sn. Os pesos foram obtidos por deriva o, pressupondo que os mesmos minimizam a variancia da diferen a entre o índice eo valor genético aditivo da planta Sn – 1. Para comparar os métodos, utilizaram-se famílias e plantas endogamicas, obtidas da popula o Vi osa. Fez-se sele o em capacidade de expans o, utilizando os três métodos nas gera es S1, S2, S3 e S4, e avaliou-se a eficiência dosmétodos comparando médias em capacidade de expans o de famílias descendentes de selecionadas por cada método em S2, S3, S4 e S5. Para compara o de médias, utilizou-se o teste t ao nível de 5% de probabilidade. Concluiu-se que a sele o combinada proposta foisuperior à sele o massal e foi, em geral, superior à sele o entre e dentro. A sele o entre e dentro foi, geralmente, superior à sele o massal. The study aimed to evaluate the relative efficiency of mass selection, among, within and of proposed new index of combined selection. The index, based on genealogy, was obtained by: IC = b1 PSn-1 + b2PFSn , wherePSn-1 is the phenotypic value of the plantSn-1; PFSn is the phenotypic value of the Sn family, descendant of the Sn-1 plant; b1 is the weight of the individual phenotypic value, and b2 it is the weight of the phenotypic value of Sn family. The weights were obtained by derivation, assuming that they minimize thevariance of the difference between the index and the value of the plant genetic additive Sn-1. To compare the methods, families and inbred plants were used, obtained from the population of Vi osa. A selection was made for popping expansion, using the three methodsin S1, S2, S3 and S4 generations, and the efficiency of the methods of comparing averages in popping expansion of descendants of families selected by each method in S2, S3, S4 and S5 was assessed. For comparison of averages, the t-test at 5% of probability was used. It is concluded that the combined selection proposal was superior to the mass selection and was, in general, higher than the selection among and within. The selection among and within was, in general, higher than the mass selection.
Prediction of genetic gain from selection indices for disease resistance in papaya hybrids Predi o de ganhos genéticos para resistência a doen as por índices de sele o em híbridos de mamoeiro
Marcelo Vivas,Silvaldo Felipe da Silveira,Messias Gonzaga Pereira
Revista Ceres , 2012,
Abstract: In order to select superior hybrids for the concentration of favorable alleles for resistance to papaya black spot, powdery mildew and phoma spot, 67 hybrids were evaluated in two seasons, in 2007, in a randomized block design with two replications. Genetic gains were estimated from the selection indices of Smith & Hazel, Pesek & Baker, Williams, Mulamba & Mock, with selection intensity of 22.39%, corresponding to 15 hybrids. The index of Mulamba & Mock showed gains more suitable for the five traits assessed when it was used the criterion of economic weight tentatively assigned. Together, severity of black spot on leaves and on fruits, characteristics considered most relevant to the selection of resistant materials, expressed percentage gain of -44.15%. In addition, there were gains for other characteristics, with negative predicted selective percentage gain. The results showed that the index of Mulamba & Mock is the most efficient procedure for simultaneous selection of papaya hybrid resistant to black spot, powdery mildew and phoma spot. Com a finalidade de selecionar híbridos superiores para concentra o de alelos favoráveis à resistência de mamoeiro à pinta-preta, oídio e mancha de phoma, foram avaliados, em duas épocas, em 2007, 67 híbridos simples, em delineamento de blocos casualizados com duas repeti es. Os ganhos genéticos foram estimados a partir dos índices de sele o de Smith & Hazel, Pesek & Baker, Williams e Mulamba & Mock, com intensidade de sele o de 22,39%, correspondendo a 15 híbridos. O índice de Mulamba & Mock evidenciou ganhos mais adequados para as cinco características avaliadas, quando utilizado o critério de peso econ mico atribuído por tentativas. Em conjunto, as severidades da pinta-preta em folhas e em frutos, características consideradas de maior interesse para a sele o de materiais resistentes, expressaram ganho percentual de -44,15%. Além disso, registraram-se ganhos para as demais características, com ganho percentual seletivo predito negativo. Conclui-se, portanto, que o uso do índice de Mulamba & Mock é o procedimento mais eficiente para sele o simultanea de híbridos de mamoeiro resistentes à pinta-preta, oídio e mancha de phoma.
Sele o de pré-cultivares de milho-pipoca baseado em índices n o-paramétricos Selecting pre-cultivars of popcorn maize based on nonparametric indices
Cássio Vittorazzi,Antonio Teixeira do Amaral Júnior,Leandro Sim?es Azeredo Gon?alves,Liliam Silvia Candido
Revista Ciência Agron?mica , 2013,
Abstract: O presente trabalho teve como objetivo fazer uma sele o prévia de pré-cultivares de milho-pipoca para o registro no MAPA, com base em diferentes caracteres, utilizando o índice de Garcia e o de soma de classifica o, priorizando-se o rendimento de gr os e capacidade de expans o. Foram avaliados 16 genótipos de milho-pipoca, sendo oito variedades de poliniza o aberta (BRS Angela, UFVM2 - Bar o de Vi osa, Vi osa, Beija-Flor, SAM, UNB2U-C3, UNB2U-C4 e UNB2U-C5) e oito híbridos (Zelia, Jade, IAC 112, P1 x P3, P1 x P7, P2 x P4, P2 x P9 e P3 x P7), em cinco ambientes. O delineamento experimental adotado foi blocos ao acaso, com três repeti es, tendo sido avaliadas as características altura de planta, estande, tombamento, capacidade de expans o e rendimento de gr os. Os efeitos dos genótipos e ambientes foram significativos para todas as características, enquanto que suas intera es o foram apenas para tombamento e rendimento de gr os. Os índices de Garcia e da soma de classifica o foram positivamente correlacionados na classifica o dos genótipos, ambos permitindo indicar as pré-cultivares UNB2U-C5 e P1 x P7 como as de melhor desempenho para regi es Norte e Noroeste do Estado do Rio de Janeiro. The present study aimed to select pre-cultivars of popcorn maize for registration in MAPA based on different characteristics, using the Garcia and total-classification indices, giving priority to grain yield and expansion capacity. Sixteen genotypes of popcorn maize: eight open-pollinated varieties (BRS Angela, UFVM2 - Bar o de Vi osa, Vi osa, Beija-Flor, SAM, UNB2U-C3, UNB2U-C4 and UNB2U-C5) and eight hybrids (Zelia, Jade, IAC 112, P1 x P3, P1 x P7, P2 x P4, P2 x P9 and P3 x P7) were evaluated in five environments. The experimental design was of randomized blocks with three replications, where the characteristics of plant height, growth, droop, expansion capacity and grain yield were evaluated. The effects of genotype and environment were significant for all characteristics, while their interactions were only significant for droop and grain yield. The Garcia and the total-classification indices correlated positively in the classification of genotypes, both indicating the pre-cultivars UNB2U-C5 and P1 x P7 as having the best performance for regions in the north and northwest of the state of Rio de Janeiro.
De novo GTP Biosynthesis Is Critical for Virulence of the Fungal Pathogen Cryptococcus neoformans  [PDF]
Carl A. Morrow,Eugene Valkov,Anna Stamp,Eve W. L. Chow,I. Russel Lee,Ania Wronski,Simon J. Williams,Justine M. Hill,Julianne T. Djordjevic,Ulrike Kappler,Bostjan Kobe,James A. Fraser
PLOS Pathogens , 2012, DOI: 10.1371/journal.ppat.1002957
Abstract: We have investigated the potential of the GTP synthesis pathways as chemotherapeutic targets in the human pathogen Cryptococcus neoformans, a common cause of fatal fungal meningoencephalitis. We find that de novo GTP biosynthesis, but not the alternate salvage pathway, is critical to cryptococcal dissemination and survival in vivo. Loss of inosine monophosphate dehydrogenase (IMPDH) in the de novo pathway results in slow growth and virulence factor defects, while loss of the cognate phosphoribosyltransferase in the salvage pathway yielded no phenotypes. Further, the Cryptococcus species complex displays variable sensitivity to the IMPDH inhibitor mycophenolic acid, and we uncover a rare drug-resistant subtype of C. gattii that suggests an adaptive response to microbial IMPDH inhibitors in its environmental niche. We report the structural and functional characterization of IMPDH from Cryptococcus, revealing insights into the basis for drug resistance and suggesting strategies for the development of fungal-specific inhibitors. The crystal structure reveals the position of the IMPDH moveable flap and catalytic arginine in the open conformation for the first time, plus unique, exploitable differences in the highly conserved active site. Treatment with mycophenolic acid led to significantly increased survival times in a nematode model, validating de novo GTP biosynthesis as an antifungal target in Cryptococcus.
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