Página 1 dos resultados de 90303 itens digitais encontrados em 0.051 segundos

SIZE AS A LINE OF LEAST RESISTANCE II: DIRECT SELECTION ON SIZE OR CORRELATED RESPONSE DUE TO CONSTRAINTS?

MARROIG, Gabriel; CHEVERUD, James
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.31%
Evolutionary change in New World Monkey (NWM) skulls occurred primarily along the line of least resistance defined by size (including allometric) variation (g(max)). Although the direction of evolution was aligned with this axis, it was not clear whether this macroevolutionary pattern results from the conservation of within population genetic covariance patterns (long-term constraint) or long-term selection along a size dimension, or whether both, constraints and selection, were inextricably involved. Furthermore, G-matrix stability can also be a consequence of selection, which implies that both, constraints embodied in g(max) and evolutionary changes observed on the trait averages, would be influenced by selection Here, we describe a combination of approaches that allows one to test whether any particular instance of size evolution is a correlated by-product due to constraints (g(max)) or is due to direct selection on size and apply it to NWM lineages as a case study. The approach is based on comparing the direction and amount of evolutionary change produced by two different simulated sets of net-selection gradients (beta), a size (isometric and allometric size) and a nonsize set. Using this approach it is possible to distinguish between the two hypotheses (indirect size evolution due to constraints or direct selection on size)...

Strategies in identifying individuals in a segregant population of common bean and implications of genotype x environment interaction in the success of selection

Mendes, M. P.; Ramalho, M. A. P.; Abreu, A. F. B.
Fonte: FUNPEC-EDITORA; RIBEIRAO PRETO Publicador: FUNPEC-EDITORA; RIBEIRAO PRETO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.29%
The objective of this study was to compare the BLUP selection method with different selection strategies in F-2:4 and assess the efficiency of this method on the early choice of the best common bean (Phaseolus vulgaris) lines. Fifty-one F-2:4 progenies were produced from a cross between the CVIII8511 x RP-26 lines. A randomized block design was used with 20 replications and one-plant field plots. Character data on plant architecture and grain yield were obtained and then the sum of the standardized variables was estimated for simultaneous selection of both traits. Analysis was carried out by mixed models (BLUP) and the least squares method to compare different selection strategies, like mass selection, stratified mass selection and between and within progeny selection. The progenies selected by BLUP were assessed in advanced generations, always selecting the greatest and smallest sum of the standardized variables. Analyses by the least squares method and BLUP procedure ranked the progenies in the same way. The coincidence of the individuals identified by BLUP and between and within progeny selection was high and of the greatest magnitude when BLUP was compared with mass selection. Although BLUP is the best estimator of genotypic value...

Estimativas de parâmetros genéticos e estudo comparativo de índices de seleção fenotípico e genético em provas de ganho de peso na raça Nelore; Estimation of genetic parameters and comparison study of phenotypic and genetic selection indexes of performance tests of Nellore beef cattle

Manicardi, Fernando Ricardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/12/2011 PT
Relevância na Pesquisa
36.28%
O presente estudo teve como objetivos estimar os parâmetros genéticos para características de crescimento e perímetro escrotal, bem como avaliar as alterações no ranking dos animais participantes de provas de ganho de peso (PGP) quando diferentes índices de seleção são usados e identificar eventuais erros de seleção. Os índices fenotípicos utilizaram os valores fenotípicos das características e os índices genéticos utilizaram os valores genéticos aditivos para a classificação dos animais. Como dados de crescimento foi analisado o peso aos 120 dias (p120), ao desmame (pdes), aos 12 meses (p12) e aos 18 meses (p18) de 3149, 3958, 2484 e 1872 animais, respectivamente, bem como o ganho de peso do desmame aos 12 meses (gpdes-12) e dos 12 aos 18 meses (gp12-18) com 1455 e 1465 animais, respectivamente. Foi analisado o perímetro escrotal ao desmame (pedes), 12 meses (pe12), 15 meses (pe15) e 18 meses (pe18) de 1535, 1166, 1212 e 852 animais, respectivamente. Os componentes de (co)variância, os parâmetros genéticos e as soluções para os efeitos fixos e aleatórios foram estimados pelo método REML, com o programa VCE6 sob modelo animal e utilizando um arquivo de pedigree com 15.522 animais. Para a comparação de ranking foram utilizados dados de 793 machos nascidos em 2008 e 2009 participantes das PGP. Dois critérios foram usados para a comparação de ranking dos animais...

Stochastic density ratio estimation and its application to feature selection; Estimação estocástica da razão de densidades e sua aplicação em seleção de atributos

Braga, Ígor Assis
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/10/2014 EN
Relevância na Pesquisa
36.3%
The estimation of the ratio of two probability densities is an important statistical tool in supervised machine learning. In this work, we introduce new methods of density ratio estimation based on the solution of a multidimensional integral equation involving cumulative distribution functions. The resulting methods use the novel V -matrix, a concept that does not appear in previous density ratio estimation methods. Experiments demonstrate the good potential of this new approach against previous methods. Mutual Information - MI - estimation is a key component in feature selection and essentially depends on density ratio estimation. Using one of the methods of density ratio estimation proposed in this work, we derive a new estimator - VMI - and compare it experimentally to previously proposed MI estimators. Experiments conducted solely on mutual information estimation show that VMI compares favorably to previous estimators. Experiments applying MI estimation to feature selection in classification tasks evidence that better MI estimation leads to better feature selection performance. Parameter selection greatly impacts the classification accuracy of the kernel-based Support Vector Machines - SVM. However, this step is often overlooked in experimental comparisons...

Comparison of selective genotyping strategies for prediction of breeding values in a population undergoing selection

Boligon, A. A.; Long, N.; Albuquerque, Lucia Galvão de; Weigel, K. A.; Gianola, D.; Rosa, G. J. M.
Fonte: Amer Soc Animal Science Publicador: Amer Soc Animal Science
Tipo: Artigo de Revista Científica Formato: 4716-4722
ENG
Relevância na Pesquisa
36.3%
Genomewide marker information can improve the reliability of breeding value predictions for young selection candidates in genomic selection. However, the cost of genotyping limits its use to elite animals, and how such selective genotyping affects predictive ability of genomic selection models is an open question. We performed a simulation study to evaluate the quality of breeding value predictions for selection candidates based on different selective genotyping strategies in a population undergoing selection. The genome consisted of 10 chromosomes of 100 cM each. After 5,000 generations of random mating with a population size of 100 (50 males and 50 females), generation G(0) (reference population) was produced via a full factorial mating between the 50 males and 50 females from generation 5,000. Different levels of selection intensities (animals with the largest yield deviation value) in G(0) or random sampling (no selection) were used to produce offspring of G(0) generation (G(1)). Five genotyping strategies were used to choose 500 animals in G(0) to be genotyped: 1) Random: randomly selected animals, 2) Top: animals with largest yield deviation values, 3) Bottom: animals with lowest yield deviations values, 4) Extreme: animals with the 250 largest and the 250 lowest yield deviations values...

Early generation selection strategy for yield and yield components in white oat

Benin,Giovani; Carvalho,Fernando Irajá Félix de; Oliveira,Antônio Costa de; Lorencetti,Claudir; Valério,Igor Pires; Schmidt,Douglas André Mallmann; Hartwig,Irineu; Ribeiro,Guilherme; Vieira,Eduardo Alano; Silva,José Antonio Gonzales da
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2005 EN
Relevância na Pesquisa
36.3%
Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 ´ UPF 7 and OR 2 ´ UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight...

Selection intensities of families and clones in potato breeding

Benavente,César Augusto Ticona; Pinto,César Augusto Brasil Pereira
Fonte: Editora da Universidade Federal de Lavras Publicador: Editora da Universidade Federal de Lavras
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
Relevância na Pesquisa
36.3%
Families selection has not been recommended as a selection method for vegetative propagated species. To verify its utility for potato improvement a series of experiments were carried out under warm temperatures (rainy season). Thirty clonal families originated from heat tolerant parents were evaluated for tuber yield and specific gravity. After obtaining the seedling generation (SG) and the first clonal generation (FCG) individual clones from a further two generations were assessed. Simulations were conducted with different intensities of family selection in SG and FCG and intensities of clonal selection in subsequent generations. The results show that family selection intensities between 50% and 60% allowed the greatest gains. Estimates of h² at the families level were always higher than at the clones level and corroborate for the more effective selection of families in early generations. The selection of families for tuber specific gravity can be made in the early generations (SG and FCG) regardless of the temperature conditions where the individual clones will be selected. The sequential selection of families with intensities of 60% (SG) and 60% (FCG) would promote greater efficiency for the selection of clones in second or third clonal generation. In the case of applying stronger selection intensities for a higher efficiency with sequential selection (SG and FCG) weaker intensities should be applied in the SG and stronger intensity in FCG . Family selection for tuber yield could be practiced in the FCG as long as the selection of clones was not held in contrasting temperature conditions.

Among and within family selection and combined half-sib family selection in Panicum maximum Jacq.

Martuscello,Janaina Azevedo; Jank,Liana; Fonseca,Dilermando Miranda da; Cruz,Cosme Damião; Cunha,Daniel de Noronha Figueiredo Vieira da
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2009 EN
Relevância na Pesquisa
36.29%
The objective of this study was to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. The experiment also proposed to compare among and within family and combined selection strategies. Ten plots of sexual plants were randomly distributed among 230 plots of apomictic accessions. After natural pollination, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female progenitor were evaluated in a randomized block design experiment, with five plants per plot and five replications. Five evaluation harvests were made in the rainy seasons and two in the dry seasons of all plants. The production and quality characteristics were evaluated. The selection criteria used was: among and within family selection and combined selection with 50% selection in both. The selection criteria used (among and within family selection and combined selection), were efficient for use in P. maximum breeding, with medium to high gains for most characteristics evaluated. The highest genetic gains were obtained from combined selection. However, among and within family selection promoted high genetic gains and may be used in P. maximum breeding. The sexual progenitors identified as numbers 7...

MULTILEVEL SELECTION WITH KIN AND NON-KIN GROUPS, EXPERIMENTAL RESULTS WITH JAPANESE QUAIL (COTURNIX JAPONICA)

Muir, William M; Bijma, P; Schinckel, A
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.28%
An experiment was conducted comparing multilevel selection in Japanese quail for 43 days weight and survival with birds housed in either kin (K) or random (R) groups. Multilevel selection significantly reduced mortality (6.6% K vs. 8.5% R) and increased weight (1.30 g/MG K vs. 0.13 g/MG R) resulting in response an order of magnitude greater with Kin than Random. Thus, multilevel selection was effective in reducing detrimental social interactions, which contributed to improved weight gain. The observed rates of response did not differ significantly from expected, demonstrating that current theory is adequate to explain multilevel selection response. Based on estimated genetic parameters, group selection would always be superior to any other combination of multilevel selection. Further, near optimal results could be attained using multilevel selection if 20% of the weight was on the group component regardless of group composition. Thus, in nature the conditions for multilevel selection to be effective in bringing about social change maybe common. In terms of a sustainability of breeding programs, multilevel selection is easy to implement and is expected to give near optimal responses with reduced rates of inbreeding as compared to group selection...

Selection, Sorting, and Routing on Mesh-Connected Processor Arrays

Narayanan, Lata ; Krizanc, Danny
Fonte: University of Rochester. Computer Science Department. Publicador: University of Rochester. Computer Science Department.
Tipo: Technical Report; Thesis
ENG
Relevância na Pesquisa
36.29%
Thesis (Ph. D.)--University of Rochester. Dept. of Computer Science, 1992. Simultaneously published in the Technical Report series.; The mesh-connected processor array has been the object of a great deal of attention in recent years, and several parallel computers have configurations based on the mesh topology. This thesis addresses the fundamental problems of selection, sorting, and routing on mesh-like networks. Sorting and selection are prototype problems, due both to their practical applications and to their role in inter-processor communication. The routing problem isolates the issue of communication between processors in an interconnection network. We show efficient randomized algorithms for selection on mesh-like networks. In particular, we show that there is a 1.22n step randomized algorithm that selects the element of rank k at the middle processor of the nxn mesh, and uses constant size queues, with high probability. In the deterministic setting, we devise a 1.44n step algorithm for selection at the middle processor. For the case when there are N elements distributed at the nodes of an nxn mesh (N > n^2), we show a deterministic algorithm that works in O(min{n^2 log (N/n^2), max{N/n^{4/3}, n}}) steps. We show optimal algorithms for selection in a variety of restricted settings: at specific locations in the mesh; when the inputs are chosen from a small domain; and for elements with specific ranks. We are able to show that adding the toroidal and/or diagonal connections to the mesh yields better algorithms for selection. We exhibit improved randomized and deterministic algorithms for selection in higher-dimensional meshes. The bounds for sorting and selection on the mesh seem to be very model-dependent. We define a general model of computation that has the queue size and the ability to replicate packets as parameters. We prove lower bounds for sorting and selection in some incarnations of this model. The architectures we consider are meshes and tori...

Objetivos E Critérios De Seleção Para Dois Sistemas De Criação De Caprinos Leiteiros No Brasil; Objectives And Selection Criteria For Two Dairy Goat Systems In Brazil

LOPES, Fernando Brito
Fonte: Universidade Federal de Goiás; BR; UFG; Doutorado em Ciência Animal; Ciências Agrárias Publicador: Universidade Federal de Goiás; BR; UFG; Doutorado em Ciência Animal; Ciências Agrárias
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
36.28%
The objectives and selection criteria used for dairy goats in Brazil are determined empirically. Brazil has climate, soil and environmental diversity, as well as distinct socioeconomic and political realities, producing distinctions among the political administrative regions of the country. The aim of this study was to obtain spatial distribution of physical, climatic and socioeconomic aspects that best discriminate the Brazilian dairy goats production, identifying the characteristics of higher socio-economic relevance for intensive or semi-intensive rearing of dairy goats, derive economic weights for selection objectives and propose selection indices whose criteria are easy to be collected by breeders of dairy goats in Brazil. The spatial analysis was performed using local climatic variables, physical and socioeconomic. The selection objectives were defined by their relative economic importance to farming systems. The economic value of each characteristic was calculated as the difference between the average profit before and after the upgrade, after increasing by 1% each feature, keeping the average remaining unchanged. It was proposed eight selection indices. The traits included in each indice were: I and V indices, milk production (MP) and lactation length (LL); II and VI indices...

Analyse épistémologique du potentiel créateur de la sélection naturelle ; entre darwinisme et postdarwinisme

Richard-Dionne, Étienne
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
36.31%
Ce mémoire propose de faire l’analyse épistémologique du pouvoir créateur de la sélection naturelle. L’objectif sera de déterminer en quelle mesure il est légitime ou non de lui attribuer un tel pouvoir. Pour ce faire, il sera question de savoir si l’explication sélectionniste peut répondre à la question de l’origine des formes structurelles du vivant. Au premier chapitre, nous verrons le raisonnement qui mena Darwin à accorder un pouvoir créateur à la sélection naturelle. Nous comprendrons alors qu’un cadre exclusivement darwinien n’est peut-être pas à même de répondre au problème de la nouveauté évolutionnaire. Au deuxième chapitre, nous verrons dans une perspective darwinienne qu’il est possible de conserver l’essence de la théorie darwinienne et d’accorder à la sélection naturelle un pouvoir créateur, bien que deux des piliers darwiniens fondamentaux doivent être remis en question. Au troisième chapitre, nous verrons dans une perspective postdarwinienne que le pouvoir cumulatif de la sélection naturelle n’est peut-être pas à même d’expliquer l’adaptation sur le plan individuel, ce qui remet lourdement en question le pouvoir créateur de la sélection naturelle. Nous comprendrons alors que le débat...

Pedigree selection for Gibberella ear rot resistance in maize

Presello, D.; Reid, L.; Butler, G.; Mather, D.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
Relevância na Pesquisa
36.28%
The pedigree method is often used for developing inbred lines in maize (Zea mays L.). This study was conducted to assess the effectiveness of pedigree selection for improving resistance to Gibberella ear rot in four maize populations. Selection was based on the severity of ear rot symptoms after inoculation with macroconidial suspensions of Fusarium graminearum (Schwabe) into the silk channel (for two populations) and into the developing kernels (for two other populations). Samples of the selfed families (S₁ to S₅), recovered from remnant seed from the selection programs, were evaluated for disease resistance during three years, using inoculation and evaluation protocols similar to those used during selection. Among-family selection was effective in both of the populations selected after silk inoculation and in one of the populations selected after kernel inoculation. Responses to selection were more evident in later than in earlier generations for both types of inoculation. Changes in the estimated genetic gain over generations were consistent with changes in the variances among families, which tended to increase in early generations and to decrease in later generations. Selection after kernel inoculation seemed to have been more effective than selection after silk inoculation in developing families with more stable resistance. Based on the results obtained here...

Estratégias de seleção para resistência a percevejos e alta produtividade em populações segregantes de soja; Selection strategies for resistance to stink bugs and high yield in soybean segregating populations

Pereira, Felipe Bermudez
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/06/2015 PT
Relevância na Pesquisa
36.28%
Na fase reprodutiva da soja, surgem os percevejos sugadores de vagens e sementes que causam danos desde a formação das vagens até o final do período de granação. Os percevejos são responsáveis por perdas significativas de produção, qualidade e potencial germinativo da semente, além de dificultarem a colheita mecanizada. Uma forma de aumentar o êxito nos programas de melhoramento refere-se à seleção simultânea de um conjunto de caracteres de importância econômica. O peso de sementes boas (não danificadas pelos percevejos) é um caráter que apresenta potencial para a seleção de genótipos resistentes e altamente produtivos. Com este trabalho buscou-se comparar diferentes critérios de seleção com base em seus ganhos estimados, para resistência ao complexo de percevejos e produtividade de grãos em duas diferentes populações de soja. Para isto, a avaliação fenotípica foi realizada na geração F2:3, em dois experimentos distintos, sendo a população derivada do cruzamento de IAC-100 x PI 295952 considerada a "população 1", e a população derivada de IAC-100 x PI 306712 considerada a "população 2". Os experimentos foram instalados em Piracicaba-SP, no ano agrícola de 2013/14, em delineamento alfa-látice 18x9...

Analysis of contract source selection strategy; Analysis of contract source selection strategy

Bastola, Jatan; Findley, Kenneth E.; Woodward, Nathan T.
Fonte: Monterey, California: Naval Postgraduate School Publicador: Monterey, California: Naval Postgraduate School
Tipo: Tese de Doutorado
Relevância na Pesquisa
36.32%
Approved for public release; distribution is unlimited; The Department of Defense (DOD) spends billions acquiring weapons systems, supplies, and services. The contract management process has to be executed diligently to ensure the government is receiving the highest return on investment. The process has six steps, two of which relate to the source selection strategy: solicitation planning and source selection. Once the acquisition team determines whether to use a lowest price technically acceptable (LPTA) or Tradeoff source selection strategy, they evaluate proposals to determine which offer presents the best value to the government. The purpose of this research is to explore potential relationships between the source selection strategy (LPTA or Tradeoff) and resultant contract outcomes. This research uses data collected from contract files and related documentation from two major systems commands (Naval Air Systems Command and Naval Sea Systems Command) to show the implication of the LPTA and Tradeoff source selection strategies. The findings suggest that an LPTA source selection strategy has a significantly shorter lead-time to contract award. The findings should be viewed with caution, however, as the sample size consisted of only six LPTA contracts. This report concludes with two recommendations to improve further research on choosing a source selection strategy and contract outcomes.; The Department of Defense (DOD) spends billions acquiring weapons systems...

L'influence de la sélection fréquence-dépendante sur le choix de partenaire chez le diamant mandarin (Taeniopygia guttata)

Hébert-Brassard, Cynthia
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
36.28%
La sélection fréquence-dépendante est un mécanisme d’évolution selon lequel l’aptitude d'un type varie en fonction de sa fréquence dans la population. Ce mécanisme joue un rôle important dans de nombreuses interactions autant interspécifiques (parasitisme, prédation, compétition), qu'intra-spécifiques entre les différents phénotypes d'une même espèce. La sélection fréquence-dépendante peut être positive ou négative et favoriser alors les phénotypes communs ou rares, respectivement. Elle a été mise en évidence dans le contexte du choix de partenaire chez plusieurs espèces, notamment chez certaines espèces d'insectes (ex.: demoiselles, drosophiles, cantharide de Pennsylvanie) et de poissons (ex.: guppys, xiphos), mais elle a été aussi récemment découverte chez l’humain. L'importance de la sélection fréquence-dépendante dans le choix de partenaire chez les espèces monogames reste tout de même peu explorée et cette étude vise à combler cette lacune en utilisant le diamant mandarin, un passereau monogame, comme modèle biologique. Nous avons étudié l'importance de ce mécanisme lorsqu'un trait est neutre et lorsque celui-ci constitue un indicateur de qualité. De plus, nous avons tenté de déterminer si la présence de rivales peut modifier la préférence initiale des femelles pour les phénotypes rares ou communs.; Frequency-dependant selection is an evolution mechanism in which the fitness of a type depend of its frequency in the population. This mechanism play an important role in several interspecific (parasitism...

Seleção sequencial em cana-de-açúcar.; Sequential selection in sugarcane.

Bressiani, José Antonio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/08/2001 PT
Relevância na Pesquisa
36.35%
Com a finalidade de avaliar o programa de melhoramento da cana-de-açúcar, este trabalho teve como objetivos: determinar o grau da interação famílias x ambientes (FA); comparar métodos de seleção na etapa inicial em termos de resposta esperada à seleção; e propor o método de seleção sequencial modificado. Para isso, foram avaliados 4752 'seedlings' pertencentes a 33 famílias (irmãs germanas e meia irmãs), em dois locais do Estado de São Paulo, Piracicaba e Jaú. Os caracteres estimados foram altura e diâmetro dos colmos, número de perfilhos, Brix % caldo da cana, toneladas de cana por hectare (TCH) e toneladas de Brix por hectare (TBH). Para validar a resposta esperada à seleção sequencial modificada, 40 famílias foram selecionadas por este método e os clones foram multiplicados até a etapa III do programa de melhoramento, a fim de fornecer a resposta realizada à seleção. Os resultados mostraram interação FA significativa para todos os caracteres avaliados. A opção por uma seleção específica implicou em aumentos de ganhos de 4,1% e 5,8% para TBH, para Piracicaba e Jaú, respectivamente, em relação à seleção de famílias generalistas, ou seja, baseada na média dos dois locais. A seleção sequencial modificada...

Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior

Head, Megan; Lindholm, Anna K.; Brooks, Rob
Fonte: Society for the Study of Evolution Publicador: Society for the Study of Evolution
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.3%
Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also...

Seleção e Análise do Perfil da Produção Científica sobre o tema Seleção de Projetos.; Selection and Profile Analysis of Scientific Literature on Project Selection.; Selección y Análisis del Perfil de la Producción Científica sobre el tema Selección de Proyectos.

Reina, Diane Rossi Maximiano; Ensslin, Sandra Rolim; Ensslin, Leonardo Ensslin; Reina, Donizete
Fonte: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade Publicador: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 02/03/2014 POR
Relevância na Pesquisa
36.3%
A relevância do processo de Seleção de Projetos para as organizações tem despertado o interesse de diversos pesquisadores em estudar o tema, para dar suporte aos gestores. Nesse sentido, com a finalidade de conhecer os estudos já publicados, a presente pesquisa seleciona um portfólio bibliográfico sobre o tema Seleção de Projetos e analisa o perfil dessas publicações. Trata-se de uma pesquisa descritiva, cuja coleta de dados foi realizada no portal de Periódicos da CAPES. A busca resultou numa amostra de 23 artigos, que compõem o portfólio bibliográfico analisado. Como resultados, destacam-se: i) Gestão & Produção, Produção e Expert Systems with Applications são os periódicos de destaque; ii) os autores mais prolíficos são Elko J. Kleinschmidt e Prasanta K. Dey, por serem os autores do portfólio bibliográfico mais citado nas referências bibliográficas dos artigos; iii) dentre os artigos analisados, três se destacam por sua relevência acadêmica: Product innovativeness from the firm's perspective: its dimensions and their relation with project selection and performance; A fuzzy AHP application in government-sponsored R&D project selection e Integrates project evaluation and selection using multiple-attribute decision-making technique.; The relevance of the project selection process for organizations has aroused the interest of many researchers in studying the subject...

Estratégia de seleção precoce para rendimento de grãos e componentes do rendimento em aveia branca; Early generation selection strategy for yield and yield components in white oat

Benin, Giovani; Carvalho, Fernando Irajá Félix de; Oliveira, Antônio Costa de; Lorencetti, Claudir; Valério, Igor Pires; Schmidt, Douglas André Mallmann; Hartwig, Irineu; Ribeiro, Guilherme; Vieira, Eduardo Alano; Silva, José Antonio Gonzales da
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/08/2005 ENG
Relevância na Pesquisa
36.3%
Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 ;´; UPF 7 and OR 2 ;´; UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight...