374 research outputs found

    Las estructuras de los centros educativos (colegios) en el siglo XX en el Perú. Diversos proyectos de reforzamiento y ejemplos de estructuración de edificaciones de la Universidad Católica del Perú

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    Los sismos ocurridos en el siglo XX, en diversas ciudades del Perú, nos han enseñado los problemas existentes en las edificaciones destinadas a aulas de colegios, institutos superiores y universidades. Estas experiencias y sus explicaciones técnicas deben ser divulgadas entre los arquitectos e ingenieros civiles, así como entre los estudiantes de estas carreras universitarias, con el fin de contribuir a enriquecer sus conocimientos. Es por estas razones que este trabajo se inicia con una breve historia del desarrollo de las edificaciones destinadas a colegios y centros de educación en general, para luego pasar a explicar las experiencias adquiridas en la evaluación de daños y en el reforzamiento de locales escolares afectados por los terremotos y culminar con criterios de estructuración de diversas edificaciones de la Universidad Católica que he proyectado.Tesi

    Evaluation of three methods for biomass estimation in small invertebrates, using three large disparate parasite species as model organisms

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    Invertebrate biomass is considered one of the main factors driving processes in ecosystems. It can be measured directly, primarily by weighing individuals, but more often indirect estimators are used. We developed two indirect and non-destructive approaches to estimate biomass of small invertebrates in a simple manner. The first one was based on clay modelling and the second one was based on image analysis implemented with open-source software. Furthermore, we tested the accuracy of the widely used geometric approximation method (third method). We applied these three different methods to three morphologically disparate model species, an acanthocephalan worm, a crustacean and a flatworm. To validate our indirect estimations and to test their accuracy, we weighed specimens of the three species and calculated their tissue densities. Additionally, we propose an uncomplicated technique to estimate thickness of individuals under a microscope, a required measurement for two of the three indirect methods tested. The indirect methods proposed in this paper provided the best approximation to direct measurements. Despite its wide use, the geometric approximation method showed the lowest accuracy. The approaches developed herein are timely because the recently increasing number of studies requiring reliable biomass estimates for small invertebrates to explain crucial processes in ecosystems

    Herramientas de ayuda a la toma de decisiones en cáncer colorrectal: una revisión

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    Aim: The objective is to collect available patient decision aids (PDA) for colorectal cancer in any of the stages of the disease and to gather published studies about the use of these tools in the last ten years Methods: A systematic review (SR) of tools for Decision-making Aid in colorectal cancer was performed since year 2000. Search includes main databases (MEDLINE, PsycINFO, EMBASE, Cochrane) as well as websites of institutions working with PDAs to search available tools. Results: After the appraisal of the found articles, we finally selected 10 studies with PDA for colorectal cancer in which patients preferences in the decision making process, disseminating strategies of the tools or the way of presenting patient information were assessed. Through the websites of institutions working with PDAs we found six tools about screening in colorectal cancer. Conclusions: There is a growing interest to involve patients with colorectal cancer in the decision making process. To do so, it’s necessary to assess patients’ values and preferences and that’s why PDAs are effective in helping both, professionals and patients. They are useful for professionals for this assessment process, and also for patients, not just to make a decision but also for being satisfied with the final decisionObjetivo: El objetivo de este trabajo es conocer los estudios publicados es los diez últimos años sobre la utilización de herramientas de ayuda a la toma de decisiones en pacientes con cáncer colorrectal, en cualquiera de las fases de la enfermedad. Así como localizar las herramientas de ayuda a la toma de decisiones que están disponibles. Método: Se ha realizado una revisión de la literatura desde el 2000 hasta el 2010 en las bases MEDLINE, PsycINFO, EMBASE y Cochrane. Así como una búsqueda en páginas webs de distintas organizaciones para la localización de herramientas disponibles Resultados: Una vez realizada la selección de los artículos, se contó con 10 artículos que presentan herramientas, evalúan las preferencias de los pacientes a la hora de tomar decisiones, evalúan las estrategias de distribución de dichas herramientas o se evalúa la forma más eficaz de presentar la información en las herramientas. A través de la búsqueda realizada mediante las páginas webs de las organizaciones se encontraron seis herramientas propiamente dichas sobre el cribado de cáncer colorrectal. Conclusiones: cada vez es mayor el interés por implicar al paciente en la toma de decisiones con respecto al cáncer colorrectal. Para ello se hace necesaria la evaluación de las preferencias y valores de los pacientes y por eso el uso de herramientas de ayuda a la toma de decisiones puede ayudar a los profesionales en esa evaluación y a los pacientes, además de a tomar la decisión, a sentirse satisfecho con ella

    Beyond counting species : a new way to look at biodiversity

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    In modern ecology, the traditional diversity indices (usually of richness, abundance, and species evenness) have been highly revealing and useful for monitoring community and ecosystem processes. However, around two decades ago, a pioneering research team noticed that these indices did not completely resolve their open questions. Thus, they suggested changing the way biodiversity was measured. At its base, this new methodology considers the distance between species (in phylogenetic or functional terms) before subsequently applying the appropriate biodiversity indices. Including phylogenetic and functional elements in the evaluation of diversity allows us to approach the concept of biodiversity in a more comprehensive way

    PACo: A Novel Procrustes Application to Cophylogenetic Analysis

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    We present Procrustean Approach to Cophylogeny (PACo), a novel statistical tool to test for congruence between phylogenetic trees, or between phylogenetic distance matrices of associated taxa. Unlike previous tests, PACo evaluates the dependence of one phylogeny upon the other. This makes it especially appropriate to test the classical coevolutionary model that assumes that parasites that spend part of their life in or on their hosts track the phylogeny of their hosts. The new method does not require fully resolved phylogenies and allows for multiple host-parasite associations. PACo produces a Procrustes superimposition plot enabling a graphical assessment of the fit of the parasite phylogeny onto the host phylogeny and a goodness-of-fit statistic, whose significance is established by randomization of the host-parasite association data. The contribution of each individual host-parasite association to the global fit is measured by means of jackknife estimation of their respective squared residuals and confidence intervals associated to each host-parasite link. We carried out different simulations to evaluate the performance of PACo in terms of Type I and Type II errors with respect to two similar published tests. In most instances, PACo performed at least as well as the other tests and showed higher overall statistical power. In addition, the jackknife estimation of squared residuals enabled more elaborate validations about the nature of individual links than the ParaFitLink1 test of the program ParaFit. In order to demonstrate how it can be used in real biological situations, we applied PACo to two published studies using a script written in the public-domain statistical software R

    Architecture, design and source code comparison of ns-2 and ns-3 network simulators

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    Ns-2 and its successor ns-3 are discrete-event simulators. Ns- 3 is still under development, but offers some interesting characteristics for developers while ns-2 still has a big user base. This paper remarks current differences between both tools from developers point of view. Leaving performance and resources consumption aside, technical issues described in the present paper might help to choose one or another alternative depending of simulation and project management requirements.Ministerio de Educación y Ciencia TIN2006-15617-C03-03Junta de Andalucía P06-TIC-229

    Analysis of source code metrics from ns-2 and ns-3 network simulators

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    Ns-2 and its successor ns-3 are discrete-event simulators which are closely related to each other as they share common background, concepts and similar aims. Ns-3 is still under development, but it offers some interesting characteristics for developers while ns-2 still has a large user base. While other studies have compared different network simulators, focusing on performance measurements, in this paper we adopted a different approach by focusing on technical characteristics and using software metrics to obtain useful conclusions. We chose ns-2 and ns-3 for our case study because of the popularity of the former in research and the increasing use of the latter. This reflects the current situation where ns-3 has emerged as a viable alternative to ns-2 due to its features and design. The paper assesses the current state of both projects and their respective evolution supported by the measurements obtained from a broad set of software metrics. By considering other qualitative characteristics we obtained a summary of technical features of both simulators including, architectural design, software dependencies or documentation policies.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0

    Ultra high-pressure homogenized emulsions stabilized by sodium caseinate: effects of protein concentration and pressure on emulsions structure and stability

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    Microstructure, physical properties and oxidative stability of emulsions treated by colloid mill (CM), conventional homogenization (CH, 15 MPa) and ultra-high-pressure homogenization (UHPH, 100–300 MPa) by using different concentrations of 1, 3 and 5 g/100 g of sodium caseinate (SC), were evaluated. The application of UHPH treatment at 200 and 300 MPa resulted in emulsions that were highly stable to creaming and oxidation, especially when the protein content increased from 1 to 3 and 5 g/100 g. Further, increasing the protein content to 3 and 5 g/100 g in UHPH emulsions tended to change the rheological behavior from Newtonian to shear thinning. CH emulsions containing 1 g/100 g of protein exhibited Newtonian flow behavior with lower tendencies to creaming compared to those formulated with 3 or 5 g/100 g. This study has proved that UHPH processing at pressures (200–300 MPa) and in the presence of sufficient amount of sodium caseinate (5 g/100 g), produces emulsions with oil droplets in nano-/submicron scale with a narrow size distribution and high physical and oxidative stabilities, compared to CM and CH treatments

    Estudio diacrónico de los usos del suelo: influencia de las superficies de cambio sobre el paisaje vegetal de la sierra de Santa Pola

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    Los cambios de uso del suelo son, sin lugar a dudas, la cara más visible de la interacción entre las fuerzas de la naturaleza y la actividad secular que desarrolla el ser humano sobre el territorio. Analizar este tipo de interacciones posibilita establecer los patrones de cambio que han configurado, en un marco temporal determinado, el paisaje vegetal de un ecosistema. Se plantea la aplicación de un estudio diacrónico, fundamentado en el análisis de las coberturas de usos del suelo y de vegetación, cartografiadas en relación con la categorización, jerarquización y clasificación de las mismas, establecidas en niveles de detalle orientados a la representación cartográfica a través de Sistemas de Información Geográfica (SIG).Land Use changes are, without doubt, the most visible face of the interaction between the forces of nature and secular activity which the human develops on the territory. Analyze this type of interaction allows to establish the patterns of change that have been configured in a certain time frame, the vegetation of an ecosystem. By applying a diachronic study, based on the analysis of the coverage of land use and vegetation, mapped in relation to the categorization, ranking and classifying by levels of detail to map with GIS.Instituto de Cultura Juan Gil-Albert. Diputación de Alicante. Ayuda a la investigación en Ciencias Sociales y Humanidades. Proyecto: “Influencia de los cambios de uso del suelo sobre el paisaje Biogeográfico de la Sierra de Santa Pola, 1956-2006”

    La actividad crediticia de un mercader en el Madrid de Carlos II: el caso de Martín Fernández de Tejada (1665-1693)

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    This paper analyzes the participation of the merchant Martin Fernández de Tejada in the credit system of the Spanish monarchy during the second half of the 17th century. The volume of loans granted in Madrid, in addition to the figure of the persons and institutions that get them, seek to contribute to the study of the credit’s role in the Spanish society in an economic climate affected by the war and the fluctuations of the money supply.El presente trabajo analiza la participación del mercader Martín Fernández de Tejada en el sistema crediticio de la Monarquía Hispánica durante la segunda mitad del siglo XVII. A través del volumen de préstamos que concede en Madrid y de las personas e instituciones que los obtienen, se pretende contribuir al estudio del papel del crédito en la sociedad española en una coyuntura económica afectada por la guerra y las fluctuaciones monetarias
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