Quantum mechanical sum rules for two model systems

Sum rules have played an important role in the development of many branches of physics since the earliest days of quantum mechanics. We present examples of one-dimensional quantum mechanical sum rules and apply them in two familiar systems, the infinite well and the single delta-function potential. These cases illustrate the different ways in which such sum rules can be realized, and the varying mathematical techniques by which they can be confirmed. Using the same methods, we also evaluate the second-order energy shifts arising from the introduction of a constant external field, namely the Stark effect.Comment: 23 pages, no figures, to appear in Am. J. Phy

X-ray spectrum of a pinned charge density wave

We calculate the X-ray diffraction spectrum produced by a pinned charge density wave (CDW). The signature of the presence of a CDW consists of two satellite peaks, asymmetric as a consequence of disorder. The shape and the intensity of these peaks are determined in the case of a collective weak pinning using the variational method. We predict divergent asymmetric peaks, revealing the presence of a Bragg glass phase. We deal also with the long range Coulomb interactions, concluding that both peak divergence and anisotropy are enhanced. Finally we discuss how to detect experimentally the Bragg glass phase in the view of the role played by the finite resolution of measurements.Comment: 13 pages 10 figure

Relaciones interpersonales y desempeño laboral en la Dirección Regional de Trabajo y Promoción del Empleo Junín - Huancayo 2017

La investigación se realizó con el objetivo de determinar la relación que existe entre las Relaciones Interpersonales y el Desempeño Laboral en la Dirección Regional de Trabajo y Promoción del Empleo Junín-Huancayo 2017, para tal emanación se utilizó un método de estudio científico de tipo básica, de nivel correlacional y diseño descriptivo-correlacional simple, no experimental de corte transversal; Asimismo, se recurrió a un instrumento habida y oportunamente validados a través del dictamen de los expertos y se demostró estadísticamente a través de Alfa y Cronbach el 0.782 estimando una excelente fiabilidad lo cual respalda su aplicación. La encuesta se empleó al 100% de la población, durante 2 días consecutivos se desarrolló su aplicación a los 52 integrantes en la Dirección Regional de Trabajo y Promoción del Empleo Junín-Huancayo. La información y datos obtenidos fueron procesados a través del uso de un software SPSS v.24, para determinar la correlación se aplicó el coeficiente de spearman, en donde se obtuvo el valor. Lo que significa que existe una correlación directa, positiva media, con un nivel de significancia de 0,000 que es menor a 0,05 significativa. En síntesis, se determina que existe una relación directa y significativa entre las Relaciones Interpersonales y el Desempeño Laboral en la Dirección Regional de Trabajo y Promoción del Empleo Junín-Huancayo 2017.Tesi

Development and Utility of an Internal Threshold Control (ITC) Real-Time PCR Assay for Exogenous DNA Detection

Sensitive and specific tests for detecting exogenous DNA molecules are useful for infectious disease diagnosis, gene therapy clinical trial safety, and gene doping surveillance. Taqman real-time PCR using specific sequence probes provides an effective approach to accurately and quantitatively detect exogenous DNA. However, one of the major challenges in these analyses is to eliminate false positive signals caused by either non-targeted exogenous or endogenous DNA sequences, or false negative signals caused by impurities that inhibit PCR. Although multiplex Taqman PCR assays have been applied to address these problems by adding extra primer-probe sets targeted to endogenous DNA sequences, the differences between targets can lead to different detection efficiencies. To avoid these complications, a Taqman PCR-based approach that incorporates an internal threshold control (ITC) has been developed. In this single reaction format, the target sequence and ITC template are co-amplified by the same primers, but are detected by different probes each with a unique fluorescent dye. Sample DNA, a prescribed number of ITC template molecules set near the limit of sensitivity, a single pair of primers, target probe and ITC probe are added to one reaction. Fluorescence emission signals are obtained simultaneously to determine the cycle thresholds (Ct) for amplification of the target and ITC sequences. The comparison of the target Ct with the ITC Ct indicates if a sample is a true positive for the target (i.e. Ct less than or equal to the ITC Ct) or negative (i.e. Ct greater than the ITC Ct). The utility of this approach was demonstrated in a nonhuman primate model of rAAV vector mediated gene doping in vivo and in human genomic DNA spiked with plasmid DNA

El liderazgo en la empresa familiar

En este trabajo he abordado desde una perspectiva teórica los aspectos más relevantes del liderazgo en la empresa familiar: Por qué es importante, los tipos de liderazgo que se pueden desarrollar, los modos de liderazgo más usuales de cada generación y los principales problemas a abordar, las prácticas de liderazgo que más favorecen el crecimiento... no sin antes dar una breve introducción a la empresa familiar y abordar la situación de la empresa familiar en España.<br /

Incidencia de la competencia argumentativa en el aprendizaje y en el mejoramiento de las prácticas ambientales en básica primaria

El presente trabajo de tipo cualitativo-descriptivo, tuvo como objetivo principal conocer la incidencia de la competencia argumentativa en el aprendizaje y en el mejoramiento de las prácticas ambientales en básica primaria. Para ello, se desarrollaron tres fases, inicialmente se elaboró y aplicó un cuestionario con el propósito de indagar los niveles argumentativos iniciales que tienen los estudiantes sobre el mejoramiento de las prácticas ambientales; posteriormente se diseñó y desarrolló una unidad didáctica, que busca promover en los estudiantes, tanto la competencia argumentativa como el aprendizaje de la temática abordada; y finalmente se aplicó por segunda vez el cuestionario inicial que es el mismo final para analizar los cambios que tuvieron las respuestas de los estudiantes en la categoría analizada, tras la aplicación de la unidad didáctica. De acuerdo a los resultados obtenidos en el momento 1 el 83% de los estudiantes se ubicaron en el nivel 1 de argumentación y el 17% en el nivel 2. En el momento 3 después de la intervención didáctica, se pudo evidenciar en las respuestas una movilización de los niveles argumentativos pasando del 1 al 2, notándose unos argumentos un poco más estructurados, en los que se incluyeron elementos o características tales como datos, conclusiones y justificaciones para dar sus explicaciones, como también se destacó el uso de los conceptos propios de las ciencias naturales a través de la interacción entre los estudiantes, los profesores y la ciencia escolar.The present work of qualitative-descriptive type, had as main objective to know the incidence of argumentative competence in learning and in the improvement of environmental practices in primary basic. For this, three phases were developed, initially a questionnaire was developed and applied with the purpose of investigating the initial argumentative levels that students have on the improvement of environmental practices; Subsequently, a didactic unit was designed and developed, which seeks to promote both the argumentative competence and the learning of the subject addressed in the students; and finally the initial questionnaire was applied for the second time, which is the same final to analyze the changes that the students' responses had in the analyzed category, after the application of the didactic unit. According to the results obtained at time 1, 83% of the students were placed in level 1 of argumentation and 17% in level 2. At time 3 after the didactic intervention, it was possible to show in the answers a mobilization of the argumentative levels from 1 to 2, noting a little more structured arguments, which included elements or characteristics such as data, conclusions and justifications to give their explanations, as well as the use of the concepts of the natural sciences through the interaction between students, teachers and school science

Gait characterization in golden retriever muscular dystrophy dogs using linear discriminant analysis

Background: Accelerometric analysis of gait abnormalities in golden retriever muscular dystrophy (GRMD) dogs isof limited sensitivity, and produces highly complex data. The use of discriminant analysis may enable simpler andmore sensitive evaluation of treatment benefits in this important preclinical model.Methods: Accelerometry was performed twice monthly between the ages of 2 and 12 months on 8 healthy and20 GRMD dogs. Seven accelerometric parameters were analysed using linear discriminant analysis (LDA). Manipulationof the dependent and independent variables produced three distinct models. The ability of each model to detect gaitalterations and their pattern change with age was tested using a leave-one-out cross-validation approach.Results: Selecting genotype (healthy or GRMD) as the dependent variable resulted in a model (Model 1) allowing agood discrimination between the gait phenotype of GRMD and healthy dogs. However, this model was not sufficientlyrepresentative of the disease progression. In Model 2, age in months was added as a supplementary dependentvariable (GRMD_2 to GRMD_12 and Healthy_2 to Healthy_9.5), resulting in a high overall misclassification rate (83.2%).To improve accuracy, a third model (Model 3) was created in which age was also included as an explanatory variable.This resulted in an overall misclassification rate lower than 12%. Model 3 was evaluated using blinded data pertainingto 81 healthy and GRMD dogs. In all but one case, the model correctly matched gait phenotype to the actualgenotype. Finally, we used Model 3 to reanalyse data from a previous study regarding the effects ofimmunosuppressive treatments on muscular dystrophy in GRMD dogs. Our model identified significant effect ofimmunosuppressive treatments on gait quality, corroborating the original findings, with the added advantages ofdirect statistical analysis with greater sensitivity and more comprehensible data representation.Conclusions: Gait analysis using LDA allows for improved analysis of accelerometry data by applying adecision-making analysis approach to the evaluation of preclinical treatment benefits in GRMD dogs

Coulombian Disorder in Periodic Systems

We study the effect of unscreened charged impurities on periodic systems. We show that the long wavelength component of the disorder becomes long ranged and dominates static correlation functions. On the other hand, because of the statistical tilt symmetry, dynamical properties such as pinning remain unaffected. As a concrete example, we focus on the effect of Coulombian disorder generated by charged impurities, on 3D charge density waves with non local elasticity. We calculate the x-ray intensity and find that it is identical to the one produced by thermal fluctuations in a disorder-free smectic-A. We discuss the consequences of these results for experiments.Comment: 11 pages, 3 figures, revtex

Desarrollo de la competencia argumentativa y su incidencia en el aprendizaje del concepto prácticas ambientales

The present investigation is of qualitative-descriptive type is in development. Which is intended to know the incidence of argumentative competence in learning and in the improvement of environmental practices in primary school. For this, the research is carried out in three phases: planning; intervention and information analysis. In phase one, the initial questionnaire is prepared and the teaching unit is designed. In phase two, the initial questionnaire is applied, which allows to know the levels of argumentation that students have regarding the concept. Then, the didactic unit with which argumentative processes are promoted is developed. Finally, the initial questionnaire, which is the same final one, is applied for the second time to know the mobilization of the argumentative levels with which the students were left. In phase three, the data collected in the initial and final questionnaire are subjected to an analysis and then be compared using the table of argumentative levels proposed by Erdurán, Simón and Osborne (2004) and Erdurán (2008) adapted by (Tamayo, 2011)La presente investigación es de tipo cualitativo-descriptivo se encuentra en desarrollo. La cual tiene como propósito conocer la incidencia de la competencia argumentativa en el aprendizaje y en el mejoramiento de las prácticas ambientales en básica primaria. Para esto, la investigación se desarrolla en tres fases: planificación; intervención y análisis de la información. En la fase uno se elabora el cuestionario inicial y se diseña la unidad didáctica. En la fase dos, se aplica el cuestionario inicial, el cual permite conocer los niveles de argumentación que tienen los estudiantes frente al concepto. Luego, se desarrolla la unidad didáctica con la que se promueven procesos argumentativos. Por último, se aplica por segunda vez el cuestionario inicial, que es el mismo final, para conocer la movilización de los niveles argumentativos con los que quedaron los estudiantes. En la fase tres, los datos recolectados en el cuestionario inicial y final son sometidos a un análisis para luego ser comparados mediante la tabla de niveles argumentativos propuesta por Erdurán, Simón y Osborne (2004) y Erdurán (2008) adaptado por (Tamayo, 2011)