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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Associação aditiva, dominante e epistática de SNPs à produção e composição do leite em vacas da raça Holandesa / Additive, dominance and epistatic association with milk yield and composition in Holstein cattle

Laiza Helena de Souza Iung 17 July 2014 (has links)
O leite bovino é um alimento essencial na nutrição humana, principalmente para os mais jovens por ser uma fonte importante de proteínas, minerais e vitaminas. A crescente demanda por quantidade e qualidade de leite nos últimos anos tem impulsionado inúmeras pesquisas, principalmente em relação ao perfil de ácidos graxos por diferir substancialmente das exigências humanas. Nutrição e melhoramento genético são os principais fatores capazes de promover a alteração da qualidade nutricional do leite. Por muito tempo as mudanças alcançadas via melhoramento genético foram obtidas exclusivamente com base na genética quantitativa, mas a partir dos anos 90 o interesse nesta área passou a ser divido com a genética molecular. Os avanços alcançados na biologia molecular obtidos por meio do mapeamento e sequenciamento do genoma das diversas espécies e de estudos de associação fenótipo-genótipo vêm auxiliando a explicar o fundo genético das características quantitativas. Atualmente, a maioria dos estudos de associação fenótipo-genótipo foram delineados para estimar apenas efeitos genéticos aditivos em um único lócus. No entanto, parte da variação observada nestes fenótipos resultam da interação entre loci ou genes, tornando estes estudos fundamentais para conhecer a origem da variação biológica destas características. Assim, os objetivos deste estudo foram: I) Associar polimorfismos de nucleotídeo único (SNPs) com características produtivas e o perfil de ácidos graxos no leite; e II) Identificar interações entre os SNPs associados a estas características no leite de bovinos da raça Holandesa. Fenótipo ajustado de 760 vacas para o efeito fixo de grupo de contemporâneo e covariáveis dias em lactação, idade à mensuração e produção de leite, e 6.553 SNPs foram considerados para realizar a associação por meio de regressão SNP a SNP. No total nove SNPs foram associados a uma ou mais características relacionadas ao teor de gordura e perfil de ácidos graxos. Algumas destas associações evidenciam a presença de epistasia e/ou pleiotropia entre estas regiões. Para a identificação de interação entre os SNPs, foram usados modelos que consideraram os efeitos individuais (aditivo e dominante) e os efeitos individuais e de interação entre os nove SNPs para comparação por meio do teste de razão de verossimilhança (LRT). Foi observado efeito epistático aditivo x dominante (P < 0,01) somente entre os marcadores ARS-BFGL-NGS-71749 e ARS-BFGL-NGS-34135, ambos situados no cromossomo 14 bovino (BTA14), para as características teor de ácidos graxos saturados e teor de ácido palmítico (C16:0). Para o melhor entendimento da sua interação biológica existe ainda a necessidade de maior conhecimento sobre as rotas metabólicas em que tais genes identificados estão situados estes marcadores. Mais estudos nestas regiões cromossômicas possibilitarão ampliar o conhecimento sobre os genes e suas interações. / Bovine milk is an essential food in human nutrition, especially for younger people for being as important source of proteins, minerals and vitamins. The growing for quantity and quality for milk in recent years has stimulated numerous studies, especially regarding the fatty acid profile by differ substantially of human requirements. Nutrition and animal breeding are the main factors which would enhance change the nutritional quality of cow milk. For a long time the changes achieved by animal breeding were obtained purely based on quantitative genetics, but from 90 the interest in this area came to be divided with molecular genetics. The advances made in the molecular biology obtained through the mapping and sequencing of the genomes of different species and genome-wide association studies is helping to explain more about the genetic background of quantitative traits. Currently, most of genome-wide association studies were designed to estimate additive genetic effects only at a single locus, excluding additional effects. However, part of the observed variation in these phenotypes result from the interaction between genes or loci, thus, such studies are also important for the understanding of the origin of biological variation of these traits, such as their metabolic and biochemical pathways. The aims of this study were: I) Associate single nucleotide polymorphisms (SNPs) with production traits and fatty acid profile in milk; and II) Identify interactions between SNPs associated with these traits in milk from Holstein cows. Phenotype adjusted of 760 cows for the fixed effects of contemporary group and covariates days in milk, age at measurement and milk yield, and information from 6,553 SNPs were considered for performing the association using single SNP regression method. A total of nine SNPs were associated with one or more traits related to the fat percentage and fatty acid profile. Some of these associations showed the presence of epistasis and/or pleiotropy between these regions. To identify interaction between SNPs, models that consider the individual effects (additive and dominance); and individual and interaction effects between the nine SNPs for comparison using the likelihood ratio test (LRT). Additive x dominance epistatic effect (P < 0.01) was observed only between markers ARS-BFGL-NGS- 71749 and ARS-BFGL-NGS-34135, both located on chromosome 14 (Bos taurus autossome, BTA14), for fat percentage (FP), saturated fatty acids (SFA) and palmitic acid (C16:0). For a better understanding of its biological interaction there is a need for greater knowledge of the metabolic pathways in with these genes identified these markers are located. More studies will enable these chromosomal regions expand knowledge about genes and their interactions.
292

Expressão gênica semi-quantitativa de receptores de gonadotrofinas em folículos dominantes de novilhas pré-púberes e adultas das raças Nelore (Bos primigenius indicus) e Marchigiana (Bos primigenius taurus) / Semi-quantitative gene expression of gonadotrophin receptors in dominant follicles of Nelore (Bos primigenius indicus) and Marchigiana (Bos primigenius taurus) prepubertal heifers and cows

José Eduardo de Oliveira Zanon 23 March 2006 (has links)
Com o objetivo de semi-quantificar a expressão gênica para receptores de gonadotrofinas nas células de folículos dominantes em animais pré-púberes (bezerras) das raças Nelore e Marchigiana e novilhas púberes da raça Nelore, buscando diferenças que possibilitem a procura de respostas para a deficiência da competência de desenvolvimento dos oócitos de animais pré-púberes que permitam a utilização destes em programas de melhoramento genético animal, foram utilizados 8 animais, sendo três bezerras Nelore, três bezerras Marchigiana, com 7 meses de idade, e duas novilhas Nelore, com 25 meses de idade. Foi realizado acompanhamento da onda folicular através de ultra-sonografia por dois meses, e os animais foram abatidos no momento que o folículo dominante apresentava diâmetro máximo (8, 10 e 14 mm, respectivamente). Folículos dominantes foram dissecados e isolados, e foi feita extração de RNA total. Foram feitas quatro reações de síntese de cDNA a partir de cada amostra. Para análise da expressão gênica semi-quantitativa, foram realizadas reações de Duplex-PCR, utilizando-se dois oligonucleotídeos iniciadores em cada reação, um para gene controle, o gapdh, e outro para o gene alvo, receptor do hormônio folículo estimulante ou receptor do hormônio luteinizante. Estas reações foram realizadas em triplicata a partir de cada fonte de cDNA de cada amostra, e os produtos foram aplicados em gel de poliacrilamida, e fotografados. Os resultados foram obtidos a partir da razão entre a intensidade da banda do gene alvo e a intensidade da banda do gene controle, e os valores médios foram analisados estatisticamente. Foi encontrada menor expressão relativa do gene do receptor de LH em bezerras da raça Nelore quando comparadas com as novilhas da raça Nelore e as bezerras da raça Marchigiana. Foi detectada a presença de um splicing alternativo para o gene do LHr, que apresentou comportamento semelhante ao gene padrão. Não foi encontrada diferença significativa na expressão do gene do FSHr entre os grupos estudados. Os resultados sugerem uma maior importância do LH nos estágios finais de desenvolvimento folicular, demonstrado aqui pela menor expressão relativa de lhr nos folículos dominantes de bezerras Nelore em relação às novilhas púberes, que pode ser um dos motivos para o baixo potencial de desenvolvimento dos oócitos destes animais após a fertilização in vitro / With the objective to semiquantify the gene expression for gonadotrophins receptors in dominant follicles in Nelore and Marchigiana prepubertal heifers and Nelore adult cows, being searched differences that make possible the search of answers for the low developmental potential of oocytes from prepubertal heifers that allow the use of these in programs of animal genetic improvement, had been used 8 animals, being three Nelore heifers, three Marchigiana heifers, with 7 months of age, and two Nelore heifers, with 25 months of age. Accompaniment of the follicular wave was carried through daily ultrasonografic exams for two months, and the animals had been slaughtered at the moment that dominant follicle presented maximum diameter (8, 10 and 14 mm, respectively). Dominant follicles had been dissected and isolated, and extraction of total RNA was performed. Four reactions of synthesis of cDNA from each sample had been made. For analysis of the semi-quantitative gene expression, reactions of Duplex-PCR had been carried through, using themselves two initiating oligonucleotídeos in each reaction, one for housekeeping gene, gapdh, and another one for the target gene, fshr and lhr. These reactions had been carried through in third copy from each source of cDNA of each sample, and the products had been applied in poliacrilamida gel electrophoresis, and photographed. The results had been gotten from the reason enter the intensity of the band of the target gene and the intensity of the band of the housekeeping gene, and the average values had been analyzed in a statistical software. Lower relative expression of lhr in Nelore heifers was found when compared with the Nelore adult cows and the Marchigiana heifers. An alternative splicing for lhr was detected, that presented similar behavior to the gene standard. Significant difference in the expression of the gene of the FSHr between the studied groups was not found. The results suggest a importance of the LH in the final periods of follicular development, demonstrated for the lower relative expression of lhr in the dominant follicles of Nelore heifers in relation to the adult cows in this study, that can after be the one of the reasons for the low developmental capacity of oocytes of these animals after in vitro fertilization
293

\'Por trás do véu e da espada\': o disfarce subjacente à representação das personagens cervantinas / \'Behind the veil and the sword\': the masquerade behind the depiction of Cervantine characters

Edwirgens Aparecida Ribeiro Lopes de Almeida 27 August 2013 (has links)
Este texto estuda as narrativas breves El celoso extremeño e Las dos doncellas, integrantes do conjunto intitulado Novelas Ejemplares, publicadas por Miguel de Cervantes, em 1613. Tendo em vista que os textos nos permitem experimentar distintas dimensões de leitura, temos, no plano explícito, a expressão desse autor conformista e ortodoxo, nas palavras de Williamson (1990) e, no plano sugestivo, um olhar irônico e crítico, sobretudo da condição e do papel da mulher, nas relações de gênero e ainda na vida em sociedade. Em outras palavras, os dois níveis sobre os quais traçamos os nossos estudos podem ser vistos, simultaneamente, isto é, no discurso explícito, estão revelados fragmentos da realidade a partir de um discurso conservador das regras prescritas, mas, por outro lado, no plano implícito, está o caráter reflexivo, crítico, às vezes, até transgressor dos costumes predominantes. Nessas narrativas estudadas, se por um lado as mulheres atuam como perfectas corderas, cumprindo as regras para uma nobre donzela ou para uma mulher casada, por outro lado, essas mesmas mulheres vencem as suas fragilidades e inseguranças no ato de tomar decisões, demonstrando certa autoridade ou deixando ver poderes ocultos femininos. Em vista do comportamento masculino, nos deparamos com homens que, por trás de toda a superioridade e privilégio ditado pela cultura vigente, revelam-se sujeitos aos desejos e domínios femininos, o que nos faz entender todo aquele controle outrora evidenciado como uma forma simbólica de poder. Tendo em conta a sutileza com que o autor trabalha artisticamente a questão, essas dimensões de leitura só são perceptíveis pela interpretação do leitor cuidadoso, tomando de empréstimo o termo cervantino, em que é capaz de identificar a dupla face de um escritor escurridizo e irónico ao invés de solemne y ejemplar. Enfim, essas controvérsias de leitura nos fazem concluir que o autor exibe, pelas páginas da ficção, uma representação da dinâmica da vida em sociedade, na qual a formação de novas personagens demonstra que a força e a vontade do ser humano predominam sobre as regras e as convenções sociais. Sendo assim, a proposta é analisar como, ao deixar entrevisto um discurso crítico e irônico, novas representações de personagens masculinas e femininas flexibilizam os mecanismos culturais que sustentam a suposta hierarquia entre os gêneros. Nessa perspectiva, entendemos que essa leitura pode revelar alguns dos mistérios escondidos como as rupturas, subversões e transgressões às convenções revelando uma sociedade secreta em que as mulheres exibem alguma autoridade num contexto de ordem, ainda, predominantemente, masculino. / This paper studies the brief narratives El celoso extremeño and Las dos doncellas, part of the collection called Novelas Ejemplares, published by Miguel de Cervantes in 1613. Considering that the texts allow us to experience different aspects of reading, we have in the explicit plan the expression of this conformist and orthodox author in the words of Williamson (1990) and in the suggestive plan we have an ironic and critical look, particularly on the womens condition and position in the gender roles and also in society life. In other words, these two levels studied can be viewed simultaneously, that is, on the explicit discourse, \'fragments of reality\' are disclosed from a conservative discourse of the prescribed rules, but on the other hand, in the implicit plan there is the reflexive, critical character which sometimes can even transgress the prevalent customs. In these studied narratives, on the one hand, women act as \'perfectas corderas\', fulfilling the rules for a noble maiden or a married woman. On the other hand, these women overcome their weaknesses and insecurities in the act of making decisions, showing certain authority or revealing female \'occult powers\'. In view of male behavior, we find men who behind the superiority and privilege dictated by the prevailing culture, reveal themselves subject to female wishes and domains making us understand all that formerly evidenced control as a \'symbolic \'form of power. Given the subtlety the author works the question with art, these reading dimensions are only perceived by the interpretation of the \'careful\' reader, borrowing the term Cervantine which is able to identify the two faces of a \'escurridizo and ironic writer instead of\' solemne y ejemplar. Anyway, these reading controversies make us conclude that the author displays a representation of the social life dynamics through the fiction pages in which the formation of new characters demonstrates that the strength and will of the human being predominate over the rules and social conventions. Therefore, the proposal is to analyze through a critical and ironic discourse how new representations of male and female characters make flexible cultural mechanisms that underpin the supposed hierarchy between genders. In this perspective, we understand that this reading can reveal some of the \'hidden mysteries\' such as disruptions, subversions and transgressions to conventions revealing a \'secret\' society in which women exhibit some authority in the context of order still predominantly male.
294

Plantabilidade de sementes de soja classificadas por largura / Plantability soybean seed classified by size

Rodrigues, Claiton 20 December 2012 (has links)
Made available in DSpace on 2014-08-20T13:44:32Z (GMT). No. of bitstreams: 1 tese_claiton_rodrigues.pdf: 611037 bytes, checksum: 71a8a51da2372a1903bb54a0a0d9073e (MD5) Previous issue date: 2012-12-20 / The change in the profile of soybean varieties which favor the reduction of population is accompanied by the necessity of enhancement in the process for classifying seeds by size, standardizing the distribution in the sowing row. The present study aimed to characterize the classification of soybean seeds by size with the purpose of precision sowing. The first experiment conceptualized sorted lots at intervals of 0.5mm, 1.00mm, and unrated by size. To that end, the retention in the dominant sieve and number of diameters found in each of the intervals evaluated were used as parameters. In the second experiment combinations of intervals of classification by size of 0.5mm, 1.00mm, and unrated by size with different seed base diameters in a soybean cultivar. 5.0mm, 5.5mm, 6.0mm, and 6.5mm diameters were used. We evaluated the percentage of sowing at normal spacing, double spacing, spacing at failure, spacing at double failure, average spacing, number of seeds per linear meter, and population per hectare. A speed of 6.5km/hr was set for evaluation and desired sowing density of 14 seeds per linear meter. In the Experiment 3 the same parameters of the Experiment 2 were evaluated, but in four different soybean cultivars. The equipment used in the Experiments 2 and 3 to evaluate the plantability was Corn Counter from Syngenta. In the Experiment 4 the evaluation involved 182 samples of soybean seed lots collected in the warehouses of seeds buying companies. A quality assessment of classification by seed company size from Brazil, Paraguay, Argentina, saved grains, and Sementes Iruña company was done. All samples were subjected to sieving retention test. RDS parameters, number of sieves, and the percentage participation of each seed diameter. Based on the results, the following conclusions were drawn: the classification of soybean seeds by size favors plantability, showing lower rates of double sowing, failures and double failures, and a better distribution in lower spacing that favors a better fit in the sowing density. The classification in the range of 0.5 mm favors the plantability indexes with high retention in the dominant sieve, and favoring the choice of sowing disks. The great majority of seeds producing companies from Brazil, Paraguay, and Argentina have no rigor in seed classification by size classification. / A mudança no perfil das variedades de soja que favorecem a redução de população vem acompanhada da necessidade de aperfeiçoamento no processo de classificação das sementes por largura, uniformizando a distribuição na linha de semeadura. O presente trabalho teve como objetivo caracterizar a classificação de sementes de soja por largura, com fins de precisão de semeadura. O primeiro experimento conceituou lotes classificados em intervalos de 0,5mm, 1,00mm e sem classificação por largura. Para tal, usou-se como parâmetros a retenção na peneira dominante e o número de diâmetros encontrados em cada um dos intervalos avaliados. No segundo experimento foram avaliadas as combinações de intervalos de classificação por largura em 0,5mm, 1,0mm e sem classificação por largura, com diferentes diâmetros base de sementes em uma cultivar de soja. Foram utilizados os diâmetros: 5,0mm, 5,5mm, 6,0mm e 6,5mm. Também, foram avaliados: percentagem de semeadura em espaçamento normal, espaçamento duplo, espaçamento em falha, espaçamento em dupla falha, espaçamento médio, número de sementes por metro linear e população por hectare. Para a avaliação fixou-se a velocidade de 6,5Km-1h e densidade de semeadura desejada de 14 sementes por metro linear. No experimento três, foram avaliados os mesmos parâmetros do experimento dois, porém em quatro diferentes cultivares de soja. Para os experimento dois e três, o equipamento utilizado para plantabilidade foi o Corn Counter, da Syngenta No experimento 4 a avaliação envolveu 182 amostras de lotes de sementes de soja coletadas em armazéns de empresas compradoras de sementes. Nesse experimento, fez-se uma avaliação da qualidade da classificação por largura de empresas de sementes originadas do Brasil, Paraguai, Argentina, semente caseira e da empresa Sementes Iruña . Todas as amostras foram submetidas ao teste de retenção de peneiras. Avaliaram-se, ainda, os parâmetros: retenção na peneira dominante (RPD), número de peneiras e participação em percentagem de cada diâmetro de semente. Com base nos resultados, obtiveram-se as seguintes conclusões: a classificação de sementes de soja por largura favorece a plantabilidade, demonstrando menores índices de semeaduras duplas, falhas e duplas falhas, e uma melhor distribuição em espaçamento normal, favorecendo um melhor ajuste na densidade de semeadura; a classificação em intervalo de 0,5mm favorece os índices de plantabilidade, apresentando alta retenção na peneira dominante, favorecendo a escolha de discos de semeadura.
295

Chromatic Evolution of the Pre-Recapitulatory Harmony in Felix Mendelssohn's Songs without Words

Abdalla Abarca, Faez Ismael, Abdalla Abarca, Faez Ismael January 2016 (has links)
In Darwinian evolution, a living population evolves when it is exposed to the selection pressures of a new biological medium. Analogously, in my chromatic evolution a chord "evolves" when it is exposed to a new chromatic medium, forcing it to adapt and harmonically modify its pitch content. This is a process by which a diatonic, consonant chord is progressively transformed into a chromatic substitute, over a span of several similar works, without losing or modifying the chord’s resolution tendencies, harmonic function, or formal location. From a Schenkerian perspective—and using Felix Mendelssohn’s Songs without Words as my corpus study—I will demonstrate how the pre-recapitulatory dominant (the root-position dominant that conventionally precedes the recapitulation) progressively evolves into a highly chromatic substitute: the dominant of the mediant.
296

Aspects combinatoires et algorithmiques des codes identifiants dans les graphes / Combinatorial and algorithmic aspects of identifying codes in graphs

Foucaud, Florent 10 December 2012 (has links)
Un code identifiant est un ensemble de sommets d'un graphe tel que, d'une part, chaque sommet hors du code a un voisin dans le code (propriété de domination) et, d'autre part, tous les sommets ont un voisinage distinct à l'intérieur du code (propriété de séparation). Dans cette thèse, nous nous intéressons à des aspects combinatoires et algorithmiques relatifs aux codes identifiants.Pour la partie combinatoire, nous étudions tout d'abord des questions extrémales en donnant une caractérisation complète des graphes non-orientés finis ayant comme taille minimum de code identifiant leur ordre moins un. Nous caractérisons également les graphes dirigés finis, les graphes non-orientés infinis et les graphes orientés infinis ayant pour seul code identifiant leur ensemble de sommets. Ces résultats répondent à des questions ouvertes précédemment étudiées dans la littérature.Puis, nous étudions la relation entre la taille minimum d'un code identifiant et le degré maximum d'un graphe, en particulier en donnant divers majorants pour ce paramètre en fonction de l'ordre et du degré maximum. Ces majorants sont obtenus via deux techniques. L'une est basée sur la construction d'ensembles indépendants satisfaisant certaines propriétés, et l'autre utilise la combinaison de deux outils de la méthode probabiliste : le lemme local de Lovasz et une borne de Chernoff. Nous donnons également des constructions de familles de graphes en relation avec ce type de majorants, et nous conjecturons que ces constructions sont optimales à une constante additive près.Nous présentons également de nouveaux minorants et majorants pour la cardinalité minimum d'un code identifiant dans des classes de graphes particulières. Nous étudions les graphes de maille au moins 5 et de degré minimum donné en montrant que la combinaison de ces deux paramètres influe fortement sur la taille minimum d'un code identifiant. Nous appliquons ensuite ces résultats aux graphes réguliers aléatoires. Puis, nous donnons des minorants pour la taille d'un code identifiant des graphes d'intervalles et des graphes d'intervalles unitaires. Enfin, nous donnons divers minorants et majorants pour cette quantité lorsque l'on se restreint aux graphes adjoints. Cette dernière question est abordée via la notion nouvelle de codes arête-identifiants.Pour la partie algorithmique, il est connu que le problème de décision associés à la notion de code identifiant est NP-complet même pour des classes de graphes restreintes. Nous étendons ces résultats à d'autres classes de graphes telles que celles des graphes split, des co-bipartis, des adjoints ou d'intervalles. Pour cela nous proposons des réductions polynomiales depuis divers problèmes algorithmiques classiques. Ces résultats montrent que dans beaucoup de classes de graphes, le problème des codes identifiants est algorithmiquement plus difficile que des problèms liés (tel que le problème des ensembles dominants).Par ailleurs, nous complétons les connaissances relatives à l'approximabilité du problème d'optimisation associé aux codes identifiants. Nous étendons le résultat connu de NP-difficulté pour l'approximation de ce problème avec un facteur sous-logarithmique (en fonction de la taille du graphe instance) aux graphes bipartis, split et co-bipartis, respectivement. Nous étendons également le résultat connu d'APX-complétude pour les graphes de degré maximum donné à une sous-classe des graphes split, aux graphes bipartis de degré maximum 4 et aux graphes adjoints. Enfin, nous montrons l'existence d'un algorithme de type PTAS pour les graphes d'intervalles unitaires. / An identifying code is a set of vertices of a graph such that, on the one hand, each vertex out of the code has a neighbour in the code (domination property), and, on the other hand, all vertices have a distinct neighbourhood within the code (separation property). In this thesis, we investigate combinatorial and algorithmic aspects of identifying codes.For the combinatorial part, we first study extremal questions by giving a complete characterization of all finite undirected graphs having their order minus one as minimum size of an identifying code. We also characterize finite directed graphs, infinite undirected graphs and infinite oriented graphs having their whole vertex set as unique identifying code. These results answer open questions that were previously studied in the literature.We then study the relationship between the minimum size of an identifying code and the maximum degree of a graph. In particular, we give several upper bounds for this parameter as a function of the order and the maximum degree. These bounds are obtained using two techniques. The first one consists in the construction of independent sets satisfying certain properties, and the second one is the combination of two tools from the probabilistic method: the Lovasz local lemma and a Chernoff bound. We also provide constructions of graph families related to this type of upper bounds, and we conjecture that they are optimal up to an additive constant.We also present new lower and upper bounds for the minimum cardinality of an identifying code in specific graph classes. We study graphs of girth at least 5 and of given minimum degree by showing that the combination of these two parameters has a strong influence on the minimum size of an identifying code. We apply these results to random regular graphs. Then, we give lower bounds on the size of a minimum identifying code of interval and unit interval graphs. Finally, we prove several lower and upper bounds for this parameter when considering line graphs. The latter question is tackled using the new notion of an edge-identifying code.For the algorithmic part, it is known that the decision problem associated to the notion of an identifying code is NP-complete, even for restricted graph classes. We extend the known results to other classes such as split graphs, co-bipartite graphs, line graphs or interval graphs. To this end, we propose polynomial-time reductions from several classical hard algorithmic problems. These results show that in many graph classes, the identifying code problem is computationally more difficult than related problems (such as the dominating set problem).Furthermore, we extend the knowledge of the approximability of the optimization problem associated to identifying codes. We extend the known result of NP-hardness of approximating this problem within a sub-logarithmic factor (as a function of the instance graph) to bipartite, split and co-bipartite graphs, respectively. We also extendthe known result of its APX-hardness for graphs of given maximum degree to a subclass of split graphs, bipartite graphs of maximum degree 4 and line graphs. Finally, we show the existence of a PTAS algorithm for unit interval graphs.
297

DIRETRIZES PARA DESBASTE DE Pinus taeda L. EM FUNÇÃO DA ALTURA DOMINANTE. / GUIDELINES FOR THINNING OF Pinus taeda L. IN FUNCTION OF THE DOMINANT HEIGHT.

Padoin, Veridiana 26 October 2007 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The study uses dominant trees to describe the tinning, because they are those that possess larger energy inside of a forest settlement. The main objective of the work is to model and to select models to describe the relationship among the potential number of trees for hectare in function of the dominant height, elaborating a system of curves guides how to aid in the determination of the tinning. The municipal and districts where are located the forests are: Cambará do Sul (RS), São Francisco de Paula (RS), Distrito de Tainhas (RS), Distrito dos Kroeff (RS), Bocaína do Sul (SC), Correia Pinto (SC), Curitibanos (SC), Lages (SC), Otacílio Costa (SC), Ponte Alta do Norte (SC) and Santa Cecília (SC). The units temporary sample random were installed using the Method of modified Prodan, or be, 12 trees were measured by unit sample being the center of the unit the dominant tree of the sample. The units were installed at forests in competition from 5 to 40 meters of dominant height. In those units they were measured: the distance of the 11 trees to the central dominant tree; diameter and the height of the 12 trees; the crown diameter, the length of total crown and the exposed crown length to the light of the 2 dominant trees of the sample. The calculated variables were the number of potential trees for hectare, the Index of relative spacing, the crown percentage and the index of competition of Glover and Hool. The modelling made calculations by the statistical package (Statistical Analysis System) version 8.0 and the adjustment of the equations and covariance analysis for the procedure GLM ( General Lineal Models). The equations that best describes the potential number of trees for hectare were Ln(Np) = 10,31285 - 1,28518*(ln(hdom) with a R²aj 0,68 and CV of 4,76% for the class of S'% of 14-20% and Ln(Np) = 10,36304 - 1,16938*(ln(hdom) with a R²aj 0,34 and CV of 5,24% for the class of S'% of 14-20%. The use of the dominant height as independent variable is efficient to describe the guidelines for tinning in the settlements of Pinus taeda. The model of negative exponential regression adjusts with good precision and low mistake the relationship among the potential number of trees for hectare and the dominant height. The variation of the values of potential frequency for hectare for a given dominant height is strongly reduced with the bedding of the data in classes of Index of relative spacing of Hart Becking larger than 14% and smaller than 14% allowing to elaborate frequency curves for hectare for those two situations. The development of the frequency curves stratified by Index of relative spacing influences in the dimension of the diameter of the trees for a same dominant height. / O estudo utiliza árvores dominantes para descrever o desbaste, pois são aquelas que possuem maior vigor dentro de um povoamento florestal. O principal objetivo do trabalho é modelar e selecionar modelos para descrever a relação entre o número potencial de árvores por hectare em função da altura dominante, elaborando um sistema de curvas guias como auxiliar na determinação do desbaste. Os municípios e distritos onde estão localizadas as florestas são: Cambará do Sul (RS), São Francisco de Paula (RS), Distrito de Tainhas (RS), Distrito dos Kroeff (RS), Bocaína do Sul (SC), Correia Pinto (SC), Curitibanos (SC), Lages (SC), Otacílio Costa (SC), Ponte Alta do Norte (SC) e Santa Cecília (SC). As unidades amostrais temporárias foram instaladas aleatoriamente utilizando o Método de Prodan modificado, ou seja, foram medidas 12 árvores por unidade amostral sendo o centro da unidade a árvore dominante da amostra. As unidades foram instaladas em florestas em competição de 5 a 40 metros de altura dominante. Nessas unidades foram medidas: a distância das 11 árvores até a árvore dominante central; o DAP e a altura das 12 árvores; o diâmetro de copa, o comprimento de copa total e o comprimento de copa exposto à luz das 2 árvores dominantes da amostra. As variáveis calculadas foram o número de árvores potenciais por hectare, o Índice de espaçamento relativo, a percentagem de copa e o índice de concorrência de Glover e Hool. A modelagem foi calculada pelo pacote estatístico SAS (Statistical Analysis System) versão 8.0 e o ajuste das equações e análise de covariância pelo procedimento GLM (General Linear Models). As equações que melhor descrevem o número potencial de árvores por hectare foram Ln(Np) = 10,31285 1,28518*(ln(hdom) com um R²aj de 0,68 e CV de 4,76% para a classe de S % de 14 20% e Ln(Np) = 10,36304 1,16938*(ln(hdom) com um R²aj de 0,34 e CV de 5,24% para a classe de S % de 14 20%. O uso da altura dominante como variável independente é eficiente para descrever as diretrizes para desbaste nos povoamentos de Pinus taeda. O modelo de regressão exponencial negativo ajusta com boa precisão e baixo erro a relação entre o número potencial de árvores por hectare e a altura dominante. A variação dos valores de freqüência potencial por hectare para uma dada altura dominante é fortemente reduzida com a estratificação dos dados em classes de Índice de espaçamento relativo de Hart Becking maior do que 14% e menor do que 14% permitindo elaborar curvas de freqüência por hectare para essas duas situações. O desenvolvimento das curvas de freqüência estratificado por Índice de espaçamento relativo influi na dimensão do diâmetro das árvores para uma mesma altura dominante.
298

Právní aspekty dominantního postavení / Legal aspects of dominant position

Topinková, Kateřina January 2016 (has links)
Smyslem práce bylo popsat a kriticky zhodnotit právní úpravu dominantního postavení a s ním úzce spojené vymezení relevantního trhu v prostředí České republiky, Evropské unie a kolébky moderního antitrustového zákonodárství Spojených států amerických. Důraz byl kladen na komparativní analýzu systémů, zejména co se týče vymezení klíčových pojmů a celkového přístupu. Nastíněn byl historický vývoj soutěžního práva se zaměřením na dominantní postavení, jehož určení může mít pro soutěžitele nepříjemné následky a nutnost větší opatrnosti. Následně byly podrobněji představeny úpravy ve vymezených systémech s ohledem na zásadní otázky stanovení dominantního postavení na trhu současně s podrobným představením vymezování relevantního trhu, kde se následně dominance určuje, přes průběžné objasňování a diskutování dalších pojmů v právních předpisech využívaných. Značný prostor byl věnován problematice substituovatelnosti výrobků a služeb, který představoval základní úskalí při vymezování relevantního trhu. Při výkladu bylo pracováno zejména s právními předpisy, klíčovými rozhodnutími soudních orgánů, doplňkovými výkladovými materiály a odbornou literaturou. Práce také částečně hodnotí účelnost a funkčnost úpravy. V praktické části práce byly rozebrány dva vzorové případy Úřadu pro ochranu hospodářské soutěže,...
299

RECOGNIZING HER CHARACTERISTICS AS A LEADER: AN EXAMINATION OF THE SELF-ASSESSMENT OF WOMEN LEADERS AS SHAPED BY SOCIAL IDENTITY THEORY AND THE CONCEPT OF DOUBLE CONSCIOUSNESS

Gregory, John C 01 January 2017 (has links)
Women leaders are grossly underrepresented in police and Army organizations and relevant research suggests that women face the most significant challenges in reaching leadership positions in male dominant organizations. Although there have been recent policy changes to increase opportunities for women in police and Army organizations, women are still barely represented in senior command and primary staff positions in police and Army organizations. When women are underrepresented, particularly at the most senior ranks, there are implications regarding cultural, structural, and attitudinal challenges that simply should not still exist in these organizations. Using qualitative methods, this study examined the experiences of women leaders, specifically senior leaders, in selected police departments and representative Army commands and staff support agencies. Specifically, the study explored the characteristics of effective women leaders to assess the perceived group affiliation of these leaders as it relates to these leadership characteristics and personal assessments of their leadership capabilities. The findings revealed that women leaders possess a multitude of characteristics that have set the conditions for them to break through the “Glass Ceiling” despite the many challenges and obstacles that exist within male dominant organizations. The findings indicate that women leaders in police and Army organizations are care-givers, selfless servants, over-achievers, and great communicators. They identify themselves by their performance and leadership acumen as opposed to their gender, race, or any other demographic descriptors. The findings also suggest that women leaders continue to be faced with challenges and obstacles that make it extremely difficult for them to become senior leaders and navigate up the chain of command within their organization, which impacts their ability to influence policy changes that could address some of these cultural, structural, and attitudinal challenges.
300

A narrative journey with the homeless youth discovering the impact of economic factors in their discourses of homelessness

Renjan, John 28 September 2007 (has links)
Human realities are formed in particular contexts, and can be understood through telling the story of experiences related with these realities. Homelessness is a reality for many in various parts of the world. The condition of homelessness involves various discourses, each of which can be dominant in different people. Dominant discourses bring with them inherent understandings which in the case of the reality of homelessness can negatively influence the daily activities and future prospects of homeless people. These dominant discourses define the experiences of the homeless people and cause them to assess themselves negatively. This study is in the field of Practical Theology, based on a social constructionist paradigm which holds that meanings are socially constructed and there is no single “Truth”. The processes of telling stories, listening to these stories and constructing new meanings make up a narrative approach to counselling, which I use in the context of interactions with homeless youth at the Street Centre run by Pretoria Community Ministries. My approach is qualitative, and the data are evolved from narrative interventions and unstructured interviews with homeless youth. As this process is a journey into the experiences and stories of these young people, empirical sampling is irrelevant. Listening to the stories of the young people from the streets filled me with enthusiasm to take this narrative journey with them through their stories. Examining the impact of economic factors in their discourses and narrations gave me new understanding of their meanings and challenged me, because many of these were unpredictable. The epistemological approach of postfoundationalism used on this journey allowed a wide range of knowledge types and interactions, which I elucidate through interdisciplinary investigation and identification of the traditions that inform the dominant discourses. The seven-movement methodology used for this work is relevant in the context of the homeless youth, because it allows me as researcher to continue the full length of the journey with the homeless youth, leading eventually to new possibilities. On the way certain themes evolved and their meanings constructed. Listening for the discourses and identifying their economic factors helped me to deconstruct these discourses, and so guide the stories into more hopeful channels. Of course, constructing alternate stories and acknowledging the importance of economic factors will not alone change the future of these young homeless people. Economic restructuring of society is needed. This possibility challenges jobless, homeless individuals not to acquiesce in the negative patterns of society, but rather to work with conviction to create new possibilities. In this project I listened to the stories of ten homeless young people, for each of which two sessions are presented in this report. These stories show that the story tellers are the real researchers, who create new alternate stories of hope in the course of this project. “God-talk” and the discussion of “God-experiences” throws light on the role of God in their lives and in their stories. The research journey charted in this report describes first the theological context and research model, and then the particular context of these young people’s lives. This is followed by descriptions of the discourses. Description of the context of the stories and interpretation of the stories themselves moves into assessment of the stories in their individual context. Interdisciplinary investigation and identification of the traditions that inform the discourses thicken our understanding of the realities experienced by these young people, and deeper interpretations arise which are applicable beyond the local context. Each petal of this flower blooms with new colours of understanding and new fragrances of possibility. The findings of this project are not the final end of this journey, but rather lights for future journeys into the experiences of homeless youth. / Thesis (PhD (Pastoral Family Therapy))--University of Pretoria, 2007. / Practical Theology / PhD / unrestricted

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