Los nuevos populismos mediáticos. La relación entre ciudadanía, medios masivos y política en Bolivia.

Sin resume

Dental clinical recommendations against COVID-19, according to scientific evidence

The information presented gives an excellent historical description of the appearance and evolution of the Coronavirus disease 2019; describes precisely the taxonomic, biological and genomic characteristics of SARS-CoV-2 and provides us with updated epidemiological data that allows us to have a clear idea of how the virus is spreading worldwide. On the other hand, it emphasizes the importance of being prepared to fight against infectious diseases because this disease has a rapid evolution that results in fear not only in people in general but also in the health professionals who must necessarily be in direct contact with the patient, as in the case of the dentist. For this reason, we would like to specify certain dental clinical recommendations, based on the scientific evidence available up to now

Sellado marginal y resistencia adhesiva de resina bulk fill aplicando gel de edta al 18% comparado con el gel de ácido fosfórico al 37% en el acondicionamiento dental in vitro

Objetivo. Evaluar el grado de sellado marginal y resistencia adhesiva en resina Bulk – Fill aplicando gel de EDTA al 18% en comparación al gel de ácido fosfórico al 37% en el acondicionamiento dental. Materiales y métodos. El tipo de estudio fue transversal, comparativo, de nivel aplicativo y diseño experimental. La muestra estuvo conformada por 60 dientes con cavidades clase I; se realizó el acondicionamiento con gel de ácido fosfórico, gel del EDTA al 18% en 60 segundos y 90 segundos. El total de la muestras fueron incubados a 37°C por 24 horas, se termocicló con 500 ciclos entre 5 a 55ºC. Para evaluar microfiltración, fueron sumergidos en azul de metileno a 37ºC por 4 horas, fueron seccionadas y observados al estereomicroscopio, para realizar la tracción se empleó la máquina de ensayos universales a una velocidad de 0.75mm/min hasta que se desprendiera el tornillo con la resina. Resultados. Las muestras acondicionadas con ácido fosfórico al 37% presenta mayor microfiltración grado 1 y el promedio de su resistencia adhesiva es de 7.97Mpa, la microfiltración obtenida con EDTA en 60 segundos presenta equidad entre grado 1 y 2; promedio de resistencia a la tracción de 8.8 Mpa y el EDTA 90 segundos presentó mayor microfiltración grado 1 y el resto 0 y 2; el promedio de resistencia fue 9.2 Mpa. Conclusión. No existen diferencias estadísticamente significativas al comparar los acondicionantes para la prueba de resistencia adhesiva, sin embargo se observó mejor sellado marginal cuando se acondicionó con gel de EDTA al 18 % por 90 segundos.Objective. To evaluate the degree of marginal sealing and adhesive strength in Bulk-Fill resin by applying 18% EDTA gel compared to 37% phosphoric acid gel in dental conditioning. Materials and methods. The study was transversal, experimental comparative, and applied. The sample group consisted of 60 teeth with Class I cavities, which were later subjected to conditioning. This was carried out separately with phosphoric acid gel for 15 seconds, and 18% EDTA gel within two different time frames: 60 and 90 seconds. All samples were incubated at 37ºC for a period of 24 hours and thermocycled between 5 to 55ºC for 500 cycles. To assess microfiltration, they were immersed in methylene blue at 37ºC for 4 hours, and were later sectioned and observed through a stereomicroscope. In order to perform the traction, the conventional testing machine was used at a speed of 0.75mm/min until the screw with the resin detached. Results: Samples conditioned with 37% phosphoric acid showed a greater degree 1 microfiltration and a mean adhesive resistance of 7.97 MPa. The same number of microfiltration grades 1 and 2 was found when using EDTA gel for 60 seconds, with a mean tensile strength of 8.8 MPa. On the other hand, applying EDTA gel for 90 seconds showed mostly grade 1 microfiltrations, and to a lesser extent, grade 0 and 2, with a mean resistance of 9.2 MPa. Conclusion: There are no statistically significant differences regarding adhesive strength between the two gels; however, better marginal filling was observed when samples were conditioned with 18% EDTA gel for 90 seconds

International Law and Transition to Peace in Colombia

In International Law and Transition to Peace in Colombia, César Rojas-Orozco analyses the role of international law in transition from armed conflict to peace, by using the analytical framework of jus post bellum and Colombia as a case study. While contemporary attention to jus post bellum has focused on its theoretical development and regarding international warfare, this book is the first work to comprehensively assess the concept in practice and in the context of a non-international armed conflict. Discussing the creative formulas adopted in Colombia to conciliate international legal requirements and the practical needs of peace, the book offers concrete elements to understand the concept of jus post bellum as a framework to guide other transitions around the world. Readership: Scholars and practitioners interested in the role of international law at peacemaking and peacebuilding, in the concept of jus post bellum, and in the Colombian transition to peace

Off the record: más que un derecho una necesidad

… Los medios buscan la verdad y la exponen, pero para llegar a ésta última instancia deben cumplic con una condición: tienen que reservarse la fuente. El publicar un testimonio o denuncia sin la referencia explícita a la fuente es un recursdo típico dentro de la teoría de la comunicación, se trata de las fuentes o declaraciones off the record

Herramienta para el diseño de elementos estructurales de madera nacional mediante los métodos ASD y LRFD

Proyecto de Graduación (Licenciatura en Ingeniería en Construcción) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería en Construcción, 2010.As a result of this project, we created a tool oriented to this material to this material so important to the sector of construction called timber. This application facilitates the design progress of raw material under LRFD and ASD methods. The application was made in excel 2007 that generates summary sheets that work in turn reports to calculate and distinct for the use of professionals involved with this type of design. During the construction of the tool took into consideration the criteria of professionals involved with the design of wood. In addition to a series of information related to this issue that one way or another were the basis for reaching an appropriate application to reduce delivery times of projects. The completion of the project leads us to recognize the importance of such a tool, to facilitate decision marking involved in this project developed which involve important raw material in the field of construction. All this for the sole purpose of optimizing as much as possible surrounding the timber is sold nationwide.Instituto Tecnológico de Costa Rica. Escuela Ingeniería en Construcción

Intrinsic noise and two-dimensional maps: Quasicycles, quasiperiodicity, and chaos

We develop a formalism to describe the discrete-time dynamics of systems containing an arbitrary number of interacting species. The individual-based model, which forms our starting point, is described by a Markov chain, which in the limit of large system sizes is shown to be very well-approximated by a Fokker-Planck-like equation, or equivalently by a set of stochastic difference equations. This formalism is applied to the specific case of two species: one predator species and its prey species. Quasi-cycles --- stochastic cycles sustained and amplified by the demographic noise --- previously found in continuous-time predator-prey models are shown to exist, and their behavior predicted from a linear noise analysis is shown to be in very good agreement with simulations. The effects of the noise on other attractors in the corresponding deterministic map, such as periodic cycles, quasiperiodicity and chaos, are also investigated.Comment: 21 pages, 12 figure

Suppressing escape events in maps of the unit interval with demographic noise

We explore the properties of discrete-time stochastic processes with a bounded state space, whose deterministic limit is given by a map of the unit interval. We find that, in the mesoscopic description of the system, the large jumps between successive iterates of the process can result in probability leaking out of the unit interval, despite the fact that the noise is multiplicative and vanishes at the boundaries. By including higher-order terms in the mesoscopic expansion, we are able to capture the non-Gaussian nature of the noise distribution near the boundaries, but this does not preclude the possibility of a trajectory leaving the interval. We propose a number of prescriptions for treating these escape events, and we compare the results with those obtained for the metastable behavior of the microscopic model, where escape events are not possible. We find that, rather than truncating the noise distribution, censoring this distribution to prevent escape events leads to results which are more consistent with the microscopic model. The addition of higher moments to the noise distribution does not increase the accuracy of the final results, and it can be replaced by the simpler Gaussian noise.Comment: 14 pages, 13 figure

Periapical Lesions and Their Relationship to Schneider’s Membrane in Cone-Beam Computed Tomography

Objective. To determine the relationship between the height of the periapical lesions adjacent to the maxillary sinus and the thickness of the Schneider membrane evaluated with cone-beam tomography. Materials and Methods. The universe was made up of 2432 tomography scans and a sample of 976, by systematic random sampling, and took into account those that presented any of the variables and/or both. For the relationship analysis, the sample was distributed according to sex, maxillary side, and age; it was formed between 18 and 86 years, in age groups of 18–36 years, 37–48 years, 49–59 years, and 60–86 years. The quantitative variables of the statistic descriptive analysis, hypothesis tests, and Spearman correlation were recorded. Results. A significantly low correlation (p < 0.010) was observed between the periapical lesions and the thickness of the Schneider membrane in women (rho = 0.38) and men (rho = 0.32); in the same way, a significantly low correlation was observed in the age groups of 18–36 years (rho = 0.27) and 37–48 years (rho = 0.28), while a significantly moderate correlation was observed in the age groups of 49–59 years (rho = 0.45) and 60–86 years (rho = 0.44), and with respect to the sides, a significantly low correlation (rho = 0.28) was obtained for the right side and a significantly moderate correlation (rho = 0.45) was obtained on the left side. Conclusion. We found that the height of the periapical lesions and the thickness of the Schneider membrane are significantly related according to age, sex, and maxillary side, this relationship being accentuated at an older age and on the left side