769 resultados para Multiplicity
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We describe here a method to generate combinatorial libraries of oligonucleotides mutated at the codon-level, with control of the mutagenesis rate so as to create predictable binomial distributions of mutants. The method allows enrichment of the libraries with single, double or larger multiplicity of amino acid replacements by appropriate choice of the mutagenesis rate, depending on the concentration of synthetic precursors. The method makes use of two sets of deoxynucleoside-phosphoramidites bearing orthogonal protecting groups [4,4′-dimethoxytrityl (DMT) and 9-fluorenylmethoxycarbonyl (Fmoc)] in the 5′ hydroxyl. These phosphoramidites are divergently combined during automated synthesis in such a way that wild-type codons are assembled with commercial DMT-deoxynucleoside-methyl-phosphoramidites while mutant codons are assembled with Fmoc-deoxynucleoside-methyl-phosphoramidites in an NNG/C fashion in a single synthesis column. This method is easily automated and suitable for low mutagenesis rates and large windows, such as those required for directed evolution and alanine scanning. Through the assembly of three oligonucleotide libraries at different mutagenesis rates, followed by cloning at the polylinker region of plasmid pUC18 and sequencing of 129 clones, we concluded that the method performs essentially as intended.
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The intent of this paper is to present a formal methodology for estimating rules of origin requirements. Section II of the paper presents the concept of the ROO. Earlier attempts to capture the costs of ROO are presented in Section III. Our suggested methodology relying on the tariff equivalents literature is presented in Section IV.
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The goal of this paper is to study the multiplicity of positive solutions of a class of quasilinear elliptic equations. Based on the mountain pass theorems and sub-and supersolutions argument for p-Laplacian operators, under suitable conditions on nonlinearity f (x, s), we show the following problem: -Delta(p)u = lambda f(x,u) in Omega, u/(partial derivative Omega) = 0, where Omega is a bounded open subset of R-N, N >= 2, with smooth boundary, lambda is a positive parameter and Delta(p) is the p-Laplacian operator with p > 1, possesses at least two positive solutions for large lambda.
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We consider the boundary value problems for nonlinear second-order differential equations of the form u '' + a(t)f (u) = 0, 0 < t < 1, u(0) = u (1) = 0. We give conditions on the ratio f (s)/s at infinity and zero that guarantee the existence of solutions with prescribed nodal properties. Then we establish existence and multiplicity results for nodal solutions to the problem. The proofs of our main results are based upon bifurcation techniques. (c) 2004 Elsevier Ltd. All rights reserved.
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We consider boundary value problems for nonlinear second order differential equations of the form u + a(t) f(u) = 0, t epsilon (0, 1), u(0) = u(1) = 0, where a epsilon C([0, 1], (0, infinity)) and f : R --> R is continuous and satisfies f (s)s > 0 for s not equal 0. We establish existence and multiplicity results for nodal solutions to the problems if either f(0) = 0, f(infinity) = infinity or f(0) = infinity, f(0) = 0, where f (s)/s approaches f(0) and f(infinity) as s approaches 0 and infinity, respectively. We use bifurcation techniques to prove our main results. (C) 2004 Elsevier Inc. All rights reserved.
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2000 Mathematics Subject Classification: 05A16, 05A17.
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Esta tesis lleva por título ”Tres ensayos sobre la multiplicidad de curvas de tipos de interés en el mercado interbancario” y está compuesta por tres artículos de investigación independientes en los que se analiza la evolución de los diferenciales del mercado interbancario del Euro en el periodo post-crisis. El objetivo es obtener información embebida en las cotizaciones de estos diferenciales emplenado distintas metodologías e identificar las variables que subyacen al fenómeno de la multiplicidad de curvas, caracterizando el papel que juegan a la hora de explicar esta evolución. El análisis se realiza según una aproximación cercana a la práctica de mercado (Capítulo 2), siguiendo técnicas de valoración de activos (Capítulo 3) y finalmente considerando métodos econométricos (Capítulo 4). El Capítulo 2, que incluye el primer ensayo, se centra en la evolución dinámica de las distintas curvas de tipos de interés surgidas a raíz de la crisis -diferenciadas por la periodicidad de pago del tipo de interés subyacente- a través del estudio de sus diferenciales respecto a la curva overnight. La metodología empleada es similar a la de Diebold and Li (2006) y se resume en tres factores principales que se interpretan como nivel, pendiente y curvatura. El análisis de componentes principales de estos factores para distintas periodicidades muestra que existen patrones comunes entre los factores de las diferentes curvas, en particular el primer componente principal explica el 90% de su variación. El estudio de los determinantes de estos factores revela importantes conclusiones sobre las fuentes de este patrón. En concreto, se observa que el nivel tiene una relación muy importante con el riesgo de crédito. Asimismo, el estudio del contenido informacional de los errores residuales del modelo -mediante el cómputo de la medida de ruido de Hu et al. (2013)- nos lleva a concluir que estos residuos tienen relación con la liquidez. El análisis de estos datos empleando téncicas VAR refuerza estos resultados...
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The relationship between indoor and outdoor concentration levels of particles in the absence and in the presence of indoor sources has been attracting an increasing level of attention. Understanding of the relationship and the mechanisms driving it, as well as the ability to quantify it, are of importance for assessment of source contribution, assessment of human exposure and for control and management of particles. It became particularly important to address this topic when evidence came from epidemiological studies on the close association between outdoor concentration levels of particles and health effects, yet with many studies showing that indoor concentrations could be significantly higher than those outdoors. This paper presents a summary of an extensive literature review on this topic conducted with an aim to identify general trends in relation to the I/O relationship emerging from studies conducted worldwide. The review considered separately a larger body of papers published on PM10, PM2.5, as well as the smaller database on particle number and number or volume size distribution. A specific focus of this paper is on naturally ventilated houses. The conclusion from the review is that despite the multiplicity of factors that play role in affecting the relationship, there are clear trends emerging in relation to the I/O relationship for particle mass concentration, enabling more general predictions to be made about the relationship. However, more research is still needed on particle number concentration and size distribution.