Significance of norms and completeness in variational based methods

By means of a simple structural problem, an important requirement often overlooked in practice on the basis functions used in Rayleigh-Ritz-Galerkin type methods is brought into focus. The problem of the static deformation of a uniformly loaded beam is solved variationally by expanding the beam displacement in a Fourier Cosine series. The potential energy functional is rendered stationary subject to the geometric boundary conditions. It is demonstrated that the variational approach does not converge to the true solution. The object is to resolve this paradox, and in so doing, indicate the practical implications of norms and completeness in an appropriate inner product space

Genome sequence of enterovirus D68 from St. Louis, Missouri, USA, 2016

Enterovirus D68 (EV-D68) was rarely observed prior to a widespread outbreak in 2014. We observed its reemergence in St. Louis in 2016 and sequenced the EV-D68 genomes from two patient samples. The 2016 viruses in St. Louis differed from those we had sequenced from the 2014 outbreak but were similar to other viruses circulating nationally in 2016

The Emergence of El-Ni\~{n}o as an Autonomous Component in the Climate Network

We construct and analyze a climate network which represents the interdependent structure of the climate in different geographical zones and find that the network responds in a unique way to El-Ni\~{n}o events. Analyzing the dynamics of the climate network shows that when El-Ni\~{n}o events begin, the El-Ni\~{n}o basin partially loses its influence on its surroundings. After typically three months, this influence is restored while the basin loses almost all dependence on its surroundings and becomes \textit{autonomous}. The formation of an autonomous basin is the missing link to understand the seemingly contradicting phenomena of the afore--noticed weakening of the interdependencies in the climate network during El-Ni\~{n}o and the known impact of the anomalies inside the El-Ni\~{n}o basin on the global climate system.Comment: 5 pages,10 figure

Applications of computer algebra to distributed parameter systems

In the analysis of vibrations of continuous elastic systems, one often encounters complicated transcendental equations with roots directly related to the system's natural frequencies. Typically, these equations contain system parameters whose values must be specified before a numerical solution can be obtained. The present paper presents a method whereby the fundamental frequency can be obtained in analytical form to any desired degree of accuracy. The method is based upon truncation of rapidly converging series involving inverse powers of the system natural frequencies. A straightforward method to developing these series and summing them in closed form is presented. It is demonstrated how Computer Algebra can be exploited to perform the intricate analytical procedures which otherwise would render the technique difficult to apply in practice. We illustrate the method by developing two analytical approximations to the fundamental frequency of a vibrating cantilever carrying a rigid tip body. The results are compared to the numerical solution of the exact (transcendental) frequency equation over a range of system parameters

The Silurian of Sardinia

The present volume “The Silurian of Sardinia” is composed of two related components. The first part comprises seven contributions introduced by an historical overview on the studies already carried out on the Silurian faunas of Sardinia. It aims to delineate a comprehensive scenario of the Silurian of Sardinia within a proper geological setting. A global overview regarding the palaeoenvironment and palaeogeography is also provided. The second part of the volume consists of seven research papers that illustrate actual knowledge on major fossil groups encountered in the Silurian limestones and shales of southern Sardinia

Gaussian capacity of the quantum bosonic channel with additive correlated Gaussian noise

We present an algorithm for calculation of the Gaussian classical capacity of a quantum bosonic memory channel with additive Gaussian noise. The algorithm, restricted to Gaussian input states, is applicable to all channels with noise correlations obeying certain conditions and works in the full input energy domain, beyond previous treatments of this problem. As an illustration, we study the optimal input states and capacity of a quantum memory channel with Gauss-Markov noise [J. Sch\"afer, Phys. Rev. A 80, 062313 (2009)]. We evaluate the enhancement of the transmission rate when using these optimal entangled input states by comparison with a product coherent-state encoding and find out that such a simple coherent-state encoding achieves not less than 90% of the capacity.Comment: 12+6 pages, 9 figures. Errors corrected, figures were made clearer, appendix improved and extende

Conjunto básico de marcadores de microsatélites identificados para el uso en estudios de genética de poblaciones en calamón común (Porphyrio porphyrio) en Java

Las poblaciones de calamón común han descendido en algunas partes del mundo debido a la degradación de los humedales y la caza furtiva. Los esfuerzos de conservación podrían beneficiarse de los estudios de genética de poblaciones que emplean marcadores de microsatélites. Aquí se describe la selección de los marcadores adecuados para tal estudio. Se han probado estos marcadores frente a la presencia de alelos nulos y desequilibrio gamético. De catorce loci candidatos, diez muestran una frecuencia de alelo nulo menor de 0,2 y no poseen desequilibrio de ligamiento significativo. Los loci seleccionados no presentaron desviación del equilibrio de Hardy–Weinberg (HWE) y tienen un contenido de información polimórfica (PIC) medio de 0,516. Sobre la base de esta prueba, se sugiere que estos loci deben ser incluidos en estudios de genética de poblaciones de esta especie.Populations of Purple Swamphen have been declining in some parts of the world due to wetland degradation and poaching. Conservation efforts might benefit from population genetic studies using microsatellite markers. Here we describe the selection of microsatellite markers suitable for such studies. We tested the markers against the evidence of the null alleles and gametic disequilibrium. From fourteen candidate loci, ten displayed a null alleles frequency of less than 0.2 and had no significant linkage disequilibrium. The selected loci showed no deviation from HWE and had a mean polymorphic information content of 0.516. Based on the test, we suggest these loci are suitable for population genetic studies of the species.Las poblaciones de calamón común han descendido en algunas partes del mundo debido a la degradación de los humedales y la caza furtiva. Los esfuerzos de conservación podrían beneficiarse de los estudios de genética de poblaciones que emplean marcadores de microsatélites. Aquí se describe la selección de los marcadores adecuados para tal estudio. Se han probado estos marcadores frente a la presencia de alelos nulos y desequilibrio gamético. De catorce loci candidatos, diez muestran una frecuencia de alelo nulo menor de 0,2 y no poseen desequilibrio de ligamiento significativo. Los loci seleccionados no presentaron desviación del equilibrio de Hardy–Weinberg (HWE) y tienen un contenido de información polimórfica (PIC) medio de 0,516. Sobre la base de esta prueba, se sugiere que estos loci deben ser incluidos en estudios de genética de poblaciones de esta especie