La construcción local de la memoria: Fotografías del museo comunitario Kaqjay de Patzicía, Guatemala

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Unitary evolution and uniqueness of the Fock representation of Dirac fields in cosmological spacetimes

We present a privileged Fock quantization of a massive Dirac field in a closed Friedmann-Robertson-Walker cosmology, partially selected by the criteria of invariance of the vacuum under the symmetries of the field equations, and unitary implementation of the dynamics. When quantizing free scalar fields in homogeneous and isotropic spacetimes with compact spatial sections, these criteria have been shown to pick out a unique Fock representation (up to unitary equivalence). Here, we employ the same criteria for fermion fields and explore whether that uniqueness result can be extended to the case of the Fock quantization of fermions. For the massive Dirac field, we start by introducing a specific choice of the complex structure that determines the Fock representation. Such structure is invariant under the symmetries of the equations of motion. We then prove that the corresponding representation of the canonical anticommutation relations admits a unitary implementation of the dynamics. Moreover, we construct a rather general class of representations that satisfy the above criteria, and we demonstrate that they are all unitarily equivalent to our previous choice. The complex structures in this class are restricted only by certain conditions on their asymptotic behavior for modes in the ultraviolet sector of the Dirac operator. We finally show that, if one assumes that these asymptotic conditions are in fact trivial once our criteria are fulfilled, then the time-dependent scaling in the definition of the fermionic annihilation and creation-like variables is essentially unique.Comment: 24 page

Mejoramiento de la productividad de una empresa cartonera en el área de mantenimiento mecánico en base a la implementación y desarrollo de la metodología 5s.

Las mejoras realizadas en una empresa cartonera situada en la ciudad de Machala, provincia de El Oro, analizando la productividad individual y colectiva, y su relación con la metodología 5S, para lograr el correcto desempeño del área de mantenimiento mecánico. Lo que se intenta conseguir es la reducción de tiempo basado en la reorganización, señalización y limpieza a profundidad para mejorar una de las áreas importantes de la empresa. Principalmente se visitó el taller de mantenimiento mecánico para realizar un diagnóstico general de cómo se encontraba el mantenimiento del área, consecuente se determinaron los pasos a seguir para la aplicación de la metodología 5S y se realizó la toma de tiempos para analizar la productividad individual de los técnicos. En el taller se realizó un análisis según la metodología 5S a los sectores importantes del proceso de mantenimiento y con los resultados se programó los pasos a seguir para su corrección. En el análisis ya mencionado se encontró herramientas en desuso y con desperfecto, materiales obsoletos, suciedad, recipiente en mala posición, pinturas caducadas y sin delimitación correcta de cada sector.Analyzing the individual and collective productivity, and its relationship with the 5S methodology, for achieving the correct performance of the mechanical maintenance area in a cardboard plant. We tried to get a time reduction based on reorganization, signaling and deep cleaning to improve one of the main areas of the company. As a first step, the mechanical maintenance workshop was visited for a getting diagnosis of how the maintenance of the area was carried out and thus to determine the steps to follow for the application of the 5S methodology, time was also taken to analyze the individual productivity of technicians. We promoted a workshop where we carried out an analysis to decide the finest regulations to implement in some important sectors of the maintenance process and with the results, the steps to be corrected were programmed. It was found some in disuse and with damage, obsolete materials, dirt, and container in bad position, expired paintings and without correct delineation of each sector. Applying the optimizations based on the 5S methodology in its entirety in the area, would help to reach the level of individual productivity of workers, increasing about 6% to 12% the Labored quality improvemen

Uniqueness of the Fock quantization of Dirac fields in 2+1 dimensions

We study the Fock quantization of a free Dirac field in 2+1-dimensional backgrounds which are conformally ultrastatic, with a time-dependent conformal factor. As it is typical for field theories, there is an infinite ambiguity in the Fock representation of the canonical anticommutation relations. Different choices may lead to unitarily inequivalent theories that describe different physics. To remove this ambiguity one usually requires that the vacuum be invariant under the unitary transformations that implement the symmetries of the equations of motion. However, in non-stationary backgrounds, where time translation is not a symmetry transformation, the requirement of vacuum invariance is in general not enough to fix completely the Fock representation. We show that this problem is overcome in the considered scenario by demanding, in addition, a unitarily implementable quantum dynamics. The combined imposition of these conditions selects a unique family of equivalent Fock representations. Moreover, one also obtains an essentially unique splitting of the time variation of the Dirac field into an explicit dependence on the background scale factor and a quantum evolution of the corresponding creation and annihilation operators.Comment: 24 pages. Document replaced to match published versio

Órgano competente respecto a la reposición laboral y la vía procedimental según la nueva ley procesal del trabajo Ley N° 29497

La nueva ley procesal del trabajo ley N°29497, fue promulgada el 13 de enero del 2010 y entro en vigencia en julio del año 2011, la misma que establece cual es el órgano competente para conocer demandas planteadas por trabajadores, y la vía procedimental para demandar reposición, existiendo duda sobre el órgano competente y la vía procedimental para garantizar la protección de los trabajadores frente al despido arbitrario, en su modalidad de despido arbitrario ya sea incausado y/o fraudulento considerando que el trabajo es un derecho fundamental y esencial de toda persona. Sin embargo, el II Pleno Jurisdiccional Supremo en Materia Laboral, realizado en lima en mayo del año 2014, ha establecido que el órgano jurisdiccional competente para conocer una pretensión de reposición por despido incausado o despido fraudulento es el juez especializado de trabajo, de conformidad con la nueva ley procesal del trabajo, es decir en el presente trabajo analizaremos el órgano competente y la vía procedimental ordinario y/o abreviado, para conocer demandas planteadas por trabajadores, que ha generado dudas sobre la competencia de los juzgados de paz letrados y juzgados especializados de trabajo y la vía procedimental cuando se traten de pretensiones no cuantificables, para garantizar los derechos de los trabajadores y evitar conductas unilaterales de los empleadores, nos referimos al despido en sus diversas modalidades, que una vez producida altera el status socioeconómicos de la parte más débil de la relación laboral.Trabajo de Suficiencia Profesiona

Uniqueness of the Fock quantization of scalar fields in a Bianchi I cosmology with unitary dynamics

The Fock quantization of free scalar fields is subject to an infinite ambiguity when it comes to choosing a set of annihilation and creation operators, choice that is equivalent to the determination of a vacuum state. In highly symmetric situations, this ambiguity can be removed by asking vacuum invariance under the symmetries of the system. Similarly, in stationary backgrounds, one can demand time-translation invariance plus positivity of the energy. However, in more general situations, additional criteria are needed. For the case of free (test) fields minimally coupled to a homogeneous and isotropic cosmology, it has been proven that the ambiguity is resolved by introducing the criterion of unitary implementability of the quantum dynamics, as an endomorphism in Fock space. This condition determines a specific separation of the time dependence of the field, so that this splits into a very precise background dependence and a genuine quantum evolution. Furthermore, together with the condition of vacuum invariance under the spatial Killing symmetries, unitarity of the dynamics selects a unique Fock representation for the canonical commutation relations, up to unitary equivalence. In this work, we generalize these results to anisotropic spacetimes with shear, which are therefore not conformally symmetric, by considering the case of a free scalar field in a Bianchi I cosmology.Comment: 23 pages. Updated to match published versio

Effect of antipredator training on spatial behaviour of male and female Greater Rheas (Rhea americana) reintroduced into the wild

The Greater Rhea (Rhea americana) is a South-American flightless bird whose populations have decreased due to poaching and fragmentation of suitable habitats, and there has been an urgent need to carry out management practices to prevent local or regional extinctions. Several studies revealed that reintroduction might be an appropriate action for increasing the viability of wild populations of this species. Nevertheless, although this is a popular and useful conservation strategy; the animals to be released should be prepared against risks like predation and dispersion that could influence the post-release success. We evaluated the effect of an antipredator training applied to captive-bred Greater Rheas before they were released into the wild, on their dispersal and home range size and overlap, supposing that the trained animals would avoid to dispersing into places with presence of predators and, consequently, they would reduce their home range. We also studied the habitat use by the released rheas. Eleven trained and nine control (untrained) animals were marked and monitored two to four times per day the first week, and from 4 to 19 consecutive days per month during four months, throughout breeding and post-breeding seasons. The locations of each animal were counted as a frequency of use of each of the five habitat types considered (crops, open areas, grassland, shrublands and salted flats) to compare these values between and within each group and sex. We estimated home range size and overlap, and the maximum linear distance travelled from the release site. The antipredator training affected the home range in different ways according to sex. Trained females exhibited smaller home ranges (mean ± S.E.: 0.54 ± 0.58 km2) than the rest of the individuals (control females 5.8 ± 0.75 km2, control and trained males: 2.11 ± 0.65 km2 and 2.96 ± 0.65 km2, respectively), whereas their overlap was greater (63.83% ± 16.95) than that of the untrained females (24.04, % ± 21.88). Males of both experimental groups showed similar distances travelled (3.21 ± 0.29 km), which were also greater than those of females (2.21 ± 0.32 km). The home ranges of males were not influenced by the training and they showed a high degree of overlapping (among control males 29.96% ± 18.95, and among trained males: 35.81% ± 18.95). Both groups similarly frequented the crops and in lesser extent open areas and grassland. Only the trained females reduced their movements and wandering as a result of the previous conditioning. They moved to crop or open areas, avoiding tall vegetation such as that present in grasslands that may difficult an earlier detection of predators. On the other hand, in the males, the influence of the reproductive season and the complex mating system exhibited by this species prevailed over the possible effects of training. Our work shows new and useful data about the spatial behaviour and reintroduction for conservation of the Greater Rhea.Fil: Vera Cortez, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Consideraciones sobre la problemática de la difícil valoración y cuantificación del daño moral

La problemática en torno a la valoración y quantum indemnizatorio del daño moral, es un tema recurrente, debido a la naturaleza del mismo, es imposible determinarse a través de una operación matemática, dado que se trata de derechos o intereses, que no pueden apreciarse en una exacta cantidad de dinero, el impacto y el quantum del daño moral, será diferente para cada afectado, aun y cuando se trate de los mismos intereses dañados, surgiendo así, el problema en torno a este tema, de cómo se debe, cuantificar el daño de tal forma que permita, no sólo indemnizar adecuadamente al sujeto pasivo del daño, sino que restrinja, la mera subjetividad de los jueces, que puede verse justificada en las decisiones judiciales que versan sobre daño moral

Dilemas da aprendizagem histórica : um estudo exploratório a partir de aulas-oficina

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de História, 2019.O ensino de História é, também, ciência e passa por diversos paradigmas que precisam de espaço para serem discutidos e aperfeiçoadas. Desta maneira, me parece urgente pensarmos no curso de História como um lugar de construção do conhecimento não apenas voltado ao bacharelado, mas, essencialmente, à licenciatura. Alem disso, é necessário refletir sobre a atuação do professor de História para além do espaço estritamente ligado à escola, considerando os elementos de aprendizagem histórica, que estão na escola mas não se circunscrevem a ela. Neste trabalho, me propus a avaliar uma experimentação histórica. Primeiramente, apresento os aspectos que, dentro da literatura de Ensino de História, guiaram minha pesquisa. A segunda parte, a experimentação em si, traz Aulas-Oficina onde pude presenciar a atuação destas no aprendizado histórico