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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.
121

Análise de polimorfismo de marcadores microssatélites do cromossomo 6 em raças bubalinas comerciais do Brasil /

Meirelles, Jacqueline de Andréa Dernowsek. January 2011 (has links)
Resumo: Os búfalos possuem importância econômica como animais de produção no cenário agropecuário brasileiro e mundial. O conhecimento de polimorfismos em marcadores microssatélites mapeados em búfalos é imprescindível para auxiliar em questões evolutivas da espécie, variabilidade genética intra e inter-populacional, além de serem potencialmente úteis para os programas de melhoramento animal. Foram utilizadas três raças comerciais bubalinas, Mediterrâneo, Jafarabadi e Murrah de rebanhos brasileiros para análise de polimorfismos visando avaliar a diversidade genética existente dentro e entre as raças. Foram analisados 30 animais de cada raça pela amplificação do DNA genômico extraído do bulbo de pelos utilizando quatro locos microssatélites localizados em um cromossomo de interesse econômico. Os produtos de PCR foram separados por eletroforese vertical em gel de poliacrilamida desnaturante. O loco IDVGA-53 não obteve sucesso na amplificação e foi descartado das análises de polimorfismo. Os locos MB099 e BL41 foram monomórficos. Os parâmetros de diversidade foram gerados para o loco CSSM054, o único polimórfico, com média de 3,33 alelos por loco. A heterozigosidade observada com média de 0,503 foi maior que a esperada, indicando excesso de heterozigotos. As raças Mediterrâneo e Jafarabadi apresentaram desvio de equilíbrio de Hardy-Weinberg. O parâmetro Theta indicou evidências de que as três raças diferem entre si, e quando analisadas duas a duas foi possível verificar alta estruturação populacional entre elas. A maior distância genética foi verificada entre as raças Mediterrâneo e Murrah. O conteúdo de informação polimórfica revelou que o loco CSSM054 foi altamente informativo para a raça Mediterrâneo, portanto, considerando todos os resultados, essa raça apresentou maior variabilidade genética / Abstract: The buffalo water are economically important livestock in Brazilian global and agricultural scenario. The knowledge of polymorphisms in microsatellites markers mapped in buffaloes is essential to assist in evolutionary studies of species, genetic variability within and between populations, as well as being potentially useful for animal breeding programs. Three commercial breeds of buffalos (Mediterranean, Jaffarabadi and Murrah) of Brazilian herds were used for polymorphisms analysis to evaluate the genetic diversity within and among them. In each breed 30 animals were analysed by amplification of genomic DND extracted from the hair bulbs using four microsatellite loci located on a chromosome of economic interest. PCR products were separated by vertical electrophoresis in denaturing polyacrylamide gel. The IDVGA-53 locus was not successful in amplifying and was discarded from the analysis of polymorphism. The loci MB099 and CSSM054 were monomorphic. The parameters of diversity were generated for the locus CSSM054, the only polymorphic, with an average of 3.33 alleles per locus. With a mean value of 0.503, the observed heterozygosity was higher than the expected, indicating excess of heterozygotes. Mediterranean and Jaffarabadi breeds had deviation of Hardy-Weinberg equilibrium. The parameter Theta indicated evidence that the three breeds differ and when they were analyzed in pairs, it was observed high population differentiation among them. The largest genetic distance was found between the Mediterranean and Murrah breeds. The polymorphic information content revealed that the locus CSSM054 was highly informative to the Mediterranean breed, therefore considering all the results that race had a high genetic variability / Orientador: Vera Fernanda Martins Hossepian de Lima / Coorientador: Maria Elisabete Jorge Amaral / Banca: Sandra Aidar de Queiroz / Banca: Beatriz da Costa Aguiar Alves Reis / Mestre
122

Variabilidade em FinFETs / Variability in FinFETs

Meinhardt, Cristina January 2014 (has links)
Circuitos integrados VLSI (Very Large Scale Integration) usando nanotecnologia demandam novos materiais, estruturas, metodologias de projeto e ferramentas de CAD para lidar com os problemas decorrentes do processo de fabricação, tais como variabilidade. Alguns tipos de concepção são mais ou menos robustos às variações de processo ou ambientais, quer sistemáticas ou aleatórias. Esta pesquisa avalia os tipos de projeto de circuitos integrados e os aspectos que podem ajudar a melhorar a capacidade de fabricação e desempenho nas futuras gerações de dispositivos. Neste contexto, é fundamental avaliar como será o comportamento da tecnologia FinFET em tecnologias além de 20nm. A tecnologia FinFET é candidata a substituir a tecnologia CMOS planar no processo de fabricação. Obter informações preditivas sobre o comportamento desta tecnologia no projeto de células é importante tanto para projetistas como para desenvolvedores de ferramentas de EDA. Esta tese explora tipos de projeto de células básicas com tecnologia FinFET. São objetivos principais a caracterização do desempenho temporal e potência, tanto dinâmica como estática, assim como a identificação dos principais parâmetros geométricos em tecnologias FinFET cuja variabilidade afete as características elétricas e a avaliação da robustez destas células aos efeitos de variabilidade de processo. A primeira contribuição deste trabalho é a exploração de tipos de projeto possíveis com a tecnologia FinFET, tais como o projeto com FinFET de 4 terminais nos estilos Short-Gate, Independent-Gate e Low-Power. Estas células foram caracterizadas e modeladas de forma a serem inseridas em um fluxo de síntese regular e comparadas com células em tecnologia bulk CMOS. A segunda contribuição deste trabalho é a identificação das principais fontes de variabilidade e a tendência de comportamento em tecnologias FinFET sub-20nm. Até o momento da elaboração deste documento, a pesquisa de estado-da-arte aponta que este foi o primeiro trabalho a investigar em nível elétrico o impacto da variabilidade em parâmetros geométricos e elétricos na potência dinâmica e estática de dispositivos FinFET sub-20nm. Finalmente, a terceira contribuição deste trabalho é quantificar a influência das flutuações da função trabalho do metal de gate em FinFETs nas tecnologias sub-20nm, traçando um panorama preditivo dos efeitos da variabilidade em tecnologias sub-20nm. / Integrated circuits VLSI (Very Large Scale Integration) using nanotechnology require new materials, structures, design methodologies and CAD tools to address the problems caused by the manufacturing process, such as variability. Some design types are more or less robust to process variations or environmental either systematic or random. This research evaluates the types and aspects of integrated circuit designs that can help to improve manufacturing capacity and performance in future generations. In this context, it is essential to assess what will be the behavior of FinFET technology technologies beyond 20nm. The FinFET technology is a candidate to replace the planar CMOS technology in the manufacturing process. To obtain predictive information about the behavior of this technology in cell design is important for both designers and developers of EDA tools. This work explores basic types of cell design with FinFET technology. Main objectives are to characterize timing and power, both dynamic and static, as well as the identification of the main geometrical parameters in FinFET technologies whose variability affects the electrical characteristics and evaluate the robustness of these cells to process variability effects. The first contribution of this work is the exploration of possible project types with FinFET technology, such as FinFET design with 4 terminals in styles Short-Gate, Independent-Gate and Low-Power. These cells were characterized and modeled in order to be inserted into one regular synthesis flow and compared with cells in bulk CMOS technology. The second contribution of this work is to identify the main sources of variability and the pattern of behavior in FinFET technology sub-20nm. By the time of this writing, the state of the art research shows that this is the first study to investigate in electrical level the variability impact of electrical and geometrical parameters in the dynamic and static power of FinFET devices sub-20nm. The third contribution of this work is to quantify the influence of metal gate workfunction fluctuations of FinFETs in sub-20nm technologies, tracing a predictive picture of the effects of variability in sub-20nm technologies.
123

Variabilidade em FinFETs / Variability in FinFETs

Meinhardt, Cristina January 2014 (has links)
Circuitos integrados VLSI (Very Large Scale Integration) usando nanotecnologia demandam novos materiais, estruturas, metodologias de projeto e ferramentas de CAD para lidar com os problemas decorrentes do processo de fabricação, tais como variabilidade. Alguns tipos de concepção são mais ou menos robustos às variações de processo ou ambientais, quer sistemáticas ou aleatórias. Esta pesquisa avalia os tipos de projeto de circuitos integrados e os aspectos que podem ajudar a melhorar a capacidade de fabricação e desempenho nas futuras gerações de dispositivos. Neste contexto, é fundamental avaliar como será o comportamento da tecnologia FinFET em tecnologias além de 20nm. A tecnologia FinFET é candidata a substituir a tecnologia CMOS planar no processo de fabricação. Obter informações preditivas sobre o comportamento desta tecnologia no projeto de células é importante tanto para projetistas como para desenvolvedores de ferramentas de EDA. Esta tese explora tipos de projeto de células básicas com tecnologia FinFET. São objetivos principais a caracterização do desempenho temporal e potência, tanto dinâmica como estática, assim como a identificação dos principais parâmetros geométricos em tecnologias FinFET cuja variabilidade afete as características elétricas e a avaliação da robustez destas células aos efeitos de variabilidade de processo. A primeira contribuição deste trabalho é a exploração de tipos de projeto possíveis com a tecnologia FinFET, tais como o projeto com FinFET de 4 terminais nos estilos Short-Gate, Independent-Gate e Low-Power. Estas células foram caracterizadas e modeladas de forma a serem inseridas em um fluxo de síntese regular e comparadas com células em tecnologia bulk CMOS. A segunda contribuição deste trabalho é a identificação das principais fontes de variabilidade e a tendência de comportamento em tecnologias FinFET sub-20nm. Até o momento da elaboração deste documento, a pesquisa de estado-da-arte aponta que este foi o primeiro trabalho a investigar em nível elétrico o impacto da variabilidade em parâmetros geométricos e elétricos na potência dinâmica e estática de dispositivos FinFET sub-20nm. Finalmente, a terceira contribuição deste trabalho é quantificar a influência das flutuações da função trabalho do metal de gate em FinFETs nas tecnologias sub-20nm, traçando um panorama preditivo dos efeitos da variabilidade em tecnologias sub-20nm. / Integrated circuits VLSI (Very Large Scale Integration) using nanotechnology require new materials, structures, design methodologies and CAD tools to address the problems caused by the manufacturing process, such as variability. Some design types are more or less robust to process variations or environmental either systematic or random. This research evaluates the types and aspects of integrated circuit designs that can help to improve manufacturing capacity and performance in future generations. In this context, it is essential to assess what will be the behavior of FinFET technology technologies beyond 20nm. The FinFET technology is a candidate to replace the planar CMOS technology in the manufacturing process. To obtain predictive information about the behavior of this technology in cell design is important for both designers and developers of EDA tools. This work explores basic types of cell design with FinFET technology. Main objectives are to characterize timing and power, both dynamic and static, as well as the identification of the main geometrical parameters in FinFET technologies whose variability affects the electrical characteristics and evaluate the robustness of these cells to process variability effects. The first contribution of this work is the exploration of possible project types with FinFET technology, such as FinFET design with 4 terminals in styles Short-Gate, Independent-Gate and Low-Power. These cells were characterized and modeled in order to be inserted into one regular synthesis flow and compared with cells in bulk CMOS technology. The second contribution of this work is to identify the main sources of variability and the pattern of behavior in FinFET technology sub-20nm. By the time of this writing, the state of the art research shows that this is the first study to investigate in electrical level the variability impact of electrical and geometrical parameters in the dynamic and static power of FinFET devices sub-20nm. The third contribution of this work is to quantify the influence of metal gate workfunction fluctuations of FinFETs in sub-20nm technologies, tracing a predictive picture of the effects of variability in sub-20nm technologies.
124

Evidence that Recent Warming is Reducing Upper Colorado River Flows

McCabe, Gregory J., Wolock, David M., Pederson, Gregory T., Woodhouse, Connie A., McAfee, Stephanie 12 1900 (has links)
The upper Colorado River basin (UCRB) is one of the primary sources of water for the western United States, and increasing temperatures likely will elevate the risk of reduced water supply in the basin. Although variability in water-year precipitation explains more of the variability in water-year UCRB streamflow than water-year UCRB temperature, since the late 1980s, increases in temperature in the UCRB have caused a substantial reduction in UCRB runoff efficiency (the ratio of streamflow to precipitation). These reductions in flow because of increasing temperatures are the largest documented temperature-related reductions since record keeping began. Increases in UCRB temperature over the past three decades have resulted in a mean UCRB water-year streamflow departure of 21306 million m(3) (or -7% of mean water-year streamflow). Additionally, warm-season (April through September) temperature has had a larger effect on variability in water-year UCRB streamflow than the cool-season (October through March) temperature. The greater contribution of warm-season temperature, relative to cool-season temperature, to variability of UCRB flow suggests that evaporation or snowmelt, rather than changes from snow to rain during the cool season, has driven recent reductions in UCRB flow. It is expected that as warming continues, the negative effects of temperature on water-year UCRB streamflow will become more evident and problematic.
125

Analysis of heart rate dynamics by methods derived from nonlinear mathematics:clinical applicability and prognostic significance

Mäkikallio, T. (Timo) 04 May 1998 (has links)
Abstract The traditional methods of analysing heart rate variability based on means and variance are unable to detect subtle but potentially important changes in interbeat heart rate behaviour. This research was designed to evaluate the clinical applicability and prognostic significance of new dynamical methods of analysing heart rate behaviour derived from nonlinear mathematics. The study covered four different patient populations, their controls and one general population of elderly people. The first patient group consisted of 38 patients with coronary artery disease without previous myocardial infarction, the second of 40 coronary artery disease patients with a prior Q-wave myocardial infarction, and the third of 45 patients with a history of ventricular tachyarrhythmia. The fourth group comprised 10 patients with a previous myocardial infarction who had experienced ventricular fibrillation during electrocardiographic recordings. The fifth group comprised a random sample of 347 community-living elderly people invited for a follow-up of 10 years after electrocardiographic recordings. Heart rate variability was analysed by traditional time and frequency domain methods. The new dynamical measures derived from nonlinear dynamics were: 1) approximate entropy, which reflects the complexity of the data, 2) detrended fluctuation analysis, which describes the presence or absence of fractal correlation properties of time series data, and 3) power-law relationship analysis, which demonstrates the distribution of spectral characteristics of RR intervals, but does not reflect the magnitude of spectral power in different spectral bands. Approximate entropy was higher in postinfarction patients (1.17 ± 0.22), but lower in coronary artery disease patients without myocardial infarction (0.93 ± 0.17) than in healthy controls (1.03 ± 014, p < 0.01, p < 0.05 respectively). It did not differ between patients with and without ventricular arrhythmia. The short term fractal-like scaling exponent of the detrended fluctuation analysis was higher in coronary artery disease patients without myocardial infarction (1.34 ± 0.15, p < 0.001), but not in postinfarction patients without arrhythmia (1.06 ± 0.13) compared with healthy controls (1.09 ± 0.13). The short term exponent was markedly reduced in patients with life-threatening arrhythmia (0.85 ± 0.25 ventricular tachycardia patients, 0.68 ± 0.18 ventricular fibrillation patients, p < 0.001 for both). The long term power-law slope of the power-law scaling analysis was lower in the ventricular fibrillation group than in postinfarction controls without arrhythmia risk (-1.63 ± 0.24 vs. -1.33 ± 0.23, p < 0.01) and predicted mortality in a general elderly population with an adjusted relative risk of 1.74 (95% CI 1.42–2.13). The present observations demonstrate that dynamic analysis of heart rate behaviour gives new insight into analysis of heart rate dynamics in various cardiovascular disorders. The breakdown of the normal fractal-like organising principle of heart rate variability is associated with an increased risk of mortality and vulnerability to life-threatening arrhythmias.
126

Assessing the variability of soil nitrogen mineralization

Bohm, Sven January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Charles W. Rice / Variable N fertilizer application recommendations would benefit from crediting the N that will be mineralized and available to the crop during the growing season. During the 1994 and 1995 growing season, the spatial and temporal pattern of N mineralization was assessed on two central Kansas corn fields. Net N mineralization was measured in the field using a buried bag and a resin core method. A 60 m sampling grid was established on the field and the N mineralization was measured at each grid point. The field N mineralization measured was then compared to three lab incubation (14 day anaerobic incubation, CO₂ evolved 1 day after rewetting, and N released on autoclaving) measurements to determine if the field N mineralization could be predicted by a laboratory test. Nitrogen mineralization in the field was highest in May and declined during the growing seasons. Patches of high N mineralization appeared and disappeared during the season, areas of high and low mineralization were not found in the same areas month after month. The semivariance of the laboratory incubations tended to be smoother near the origin than the field incubations, indicating that the field incubations were subject to more sources of variability (such as microclimatic variations) than the laboratory incubations. Crop yields were not correlated with N mineralization in these fields. Soil moisture appeared to be more important to crop yields than the N contributed by mineralization. In these fields N mineralization does not need to be included in N fertilization recommendations unless the amount of fertilizer applied is much lower than in this study. Finally, a method to estimate the initial δ¹³ C content of a soil is proposed. This method can be used if a location can be found that has had a continuous C₃, a continuous C₄crop and a C₃/ C₄rotation treatment.
127

Vliv eura na export ČR (anglicky) / The Impact of Exchange Rate Volatility on Czech Real Export

Jurečka, Peter January 2007 (has links)
This diploma thesis deals with the impact of real exchange rate volatility on real export of the Czech Republic. In the first part, theoretical aspects of this relationship are examined, explaining both - positive and negative ? effects on bilateral and aggregate trade flows. Further on, empirical data and econometric tools are employed to capture the relationship between real export and its main determinants for the case of Czech Republic in the past decade. After the brief theoretical introduction to time series econometrics, the particular export demand model is proposed and various cointegration techniques are explained and applied to examine the long-run equilibrium but also short-run dynamics.
128

Genetic diversity and hybridisation estimates of Arctocephalus tropicalis and A. gazella from Marion Island

Maboko, Vongani Jasinta 21 October 2009 (has links)
In this study, hypervariable region I (HVRI) of the mitochondrial DNA (mtDNA) control region, and five microsatellite loci were used to assess genetic variability and the extent of hybridization between the two fur seals (Arctocephalus tropicalis and A. gazella), that occur on Sub-Antarctic Marion Island. Both species were harvested during the 18th and 19th centuries, leading to a reduction in population size and the extinction of A. gazella at some localities. Whilst both species have recovered and are increasing in size, it is not clear to what extent sealing has affected genetic variation, although a more pronounced effect would be expected for A. gazella, given the more intensive harvesting of this species. The current study confirmed this hypothesis and revealed that A. gazella had a nucleotide diversity of 2.9 % whilst for A. tropicalis it was 4.2 %, across the HRVI mtDNA region sequenced. For microsatellite DNA, genetic variation in A. tropicalis was higher than in A. gazella in terms of the total number of alleles detected and the level of heterozygosity (HE=0.875, HO=0.845, mean number of alleles=13.6 and HE=0.799, HO=0.781, mean number of alleles=13, respectively). Diversity in both species is among the highest recorded in pinnipeds to date, and suggests that sealing did not overly affect the levels of genetic variation in these species. In terms of population structure, A. tropicalis show a high level of population structure, as indicated by the ΦST of 0.32 between Marion and Gough Island. Furthermore, the A. tropicalis haplotype tree comprising individuals from Marion, Iles Crozet, Gough, and Amsterdam islands, recovered three divergent evolutionary lineages with bootstrap values of 86% and 98%, for two of these lineages, indicating strong genetic structure and independent evolution. Shared haplotypes between Marion and other islands confirmed genetic exchanges, whilst the grouping of Marion and Gough Islands together is indicative of regular migration between these two islands. For A. gazella, the haplotype tree recovered numerous instances of grouping of individuals from Marion and Bouvetøya Islands confirming the hypothesis Bouvetøya is likely source of immigrants to Marion Island. This was further confirmed by low population differentiation between these two islands (FST = 0.062 and ΦST of 0.08). The level of hybridization between these species was low at Marion Island with only one hybrid being detected among the 134 animals for which mtDNA data were generated, corresponding to 0.75%. The same individual was identified as a hybrid, following microsatellite profiling of 146 animals, corresponding to a hybridization estimate of 0.68 %. This hybrid individual was classified phenotypically as A. gazella and genotypically was shown to have A. tropicalis ancestry. This level of hybridization is low compared to the other islands where the two species co-occur. However as the samples used in this study were primarily collected from species-specific sites, this may be an underestimate, and the studies focusing on sites where they are known to occur symaptrically, may yield higher estimates. / Dissertation (MSc)--University of Pretoria, 2009. / Zoology and Entomology / unrestricted
129

Study on High Invasibility of Ulex europaeus: What Induces the Invasiveness of Ulex europaeus? / ハリエニシダの侵入性に関する研究 ―何がハリエニシダの侵入性を引き起こしているのか―

Hozawa, Mika 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22481号 / 農博第2385号 / 新制||農||1075(附属図書館) / 学位論文||R2||N5261(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 縄田 栄治, 教授 北山 兼弘, 教授 冨永 達 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
130

Variabilité glycémique : exploration in vitro des fonctions cellulaires et mitochondriales sur la lignée de cardiomyocyte HL-1 / Glycemic variability : in vitro exploration of mitochondrial and cellular functions on HL-1 cardiomyocyte cell line

Mordel, Patrick 18 December 2017 (has links)
Le diabète est associé à une augmentation de risque de maladie cardiovasculaire et une dérégulation du métabolisme. Il a été suggéré que la variabilité glycémique (VG) pouvait avoir un rôle dans le développement des complications du diabète. Afin d’étudier et de caractériser les dysfonctions induites par la VG, nous avons mis au point un modèle in vitro mimant la VG sur la lignée de cardiomyocytes HL-1. Nous avons ainsi développé un traitement de 12 heures, mimant hypoglycémie, normoglycémie, hyperglycémie et VG. L’étude de la signalisation cellulaire ne nous a pas permis de montrer un rôle délétère de la VG. Nous avons toutefois mis en évidence que la VG participait à des dysfonctions mitochondriales. En effet en situation de fluctuations en glucose, les mitochondries des cellules HL-1 présentent une augmentation de leur potentiel de membrane, ainsi qu’une augmentation de la production d’anions superoxydes. Bien que nous n’ayons pas réussi à montrer de perturbation de la chaîne respiratoire après 12 heures d’exposition, nous avons pu montrer que 72 heures d’exposition provoquaient une baisse de la respiration mitochondriale. Nous avons enfin étudié l’impact des fluctuations en glucose sur la susceptibilité au développement de lésions d’hypoxie, et avons montré que les lésions sont majorées après 36 heures d’hypoxie en cas d’exposition à des fluctuations en glucose. Nos résultats montrent un rôle délétère de la VG, néanmoins des expériences complémentaires sont nécessaires afin de caractériser de manière plus précise les mécanismes impliqués. / Diabetes mellitus is associated with higher risk of cardiovascular disease and metabolism dysregulation. Glycemic variability (GV) has been suggested as a risk factor in diabetic complication. In order to characterize dysfunctions induced by GV, we developed an in vitro model that transpose GV on the cardiac cell line HL-1. We exposed our cells to a treatment of 12 hours miming hypoglycemia, normoglycemia, hyperglycemia and GV. The exploration of signaling pathways didn’t allow us to show a deleterious effect of glucose fluctuation. However we were able to point mitochondrial alteration under glucose fluctuation. HL-1 cells mitochondria exhibit a higher membrane potential and an increase of superoxide anion production. Although we didn’t show any alteration in mitochondrial respiration after 12 hours of exposition, we showed that after 72 hours of glucose fluctuation, HL-1 cells showed a decrease in mitochondrial respiration. We finally studied the impact of glucose fluctuation on the susceptibility to develop hypoxic injuries. We showed that after 36 hours of hypoxia, injuries were higher for cells exposed to glucose fluctuation. Our results indicate a deleterious effect of GV, but additional experiments are needed to better characterize the mechanisms.

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