La investigación mediante experimentos. El reto de estudiar causas y efectos

Este capítulo es una explicación sencilla de la aplicación de los experimentos a la investigación social. El texto explica en qué consiste un experimento y las ventajas que tiene investigar mediante experimentos en las ciencias sociales. Se explica un diseño experimental básico y conceptos relevantes en el diseño de los experimentos como "grupo de control", "aleatorización", etc. El texto explicita las ventajas e inconvenientes que la literarutura suele atribuir a la investigación mediante experimentos. Se completa el texto con ejemplos clásicos de uso de experimentos en investigaciones sociales: se hace referencia a varias de las investigaciones del equipo de Hovland sobre persuasión en la Universidad de Yale y al conocido experimento de Milgram sobre la obedicencia a la autoridad

Mentiras: historias ciertas en medios con prestigio social

Las más prestigiosas publicaciones del mundo difunden informaciones falsas... de vez en cuando. La cantidad de veces que esto se ha producido en los últimos tiempos empieza a inquietar a la profesión y a la sociedad. El texto relata casos relevantes en los que medios de comunicación o publicaciones científicas han publicado informaciones que, posteriormente, se demostraron falsas

Distant emitters in ultrastrong waveguide QED: Ground-state properties and non-Markovian dynamics

Starting from the paradigmatic spin-boson model (SBM), we investigate the static and dynamical properties of a system of two distant two-level emitters coupled to a one-dimensional Ohmic waveguide beyond the rotating wave approximation. Employing static and dynamical polaron Ansätze we study the effects of finite separation distance on the behavior of the photon-mediated Ising-like interaction, qubit frequency renormalization, ground-state magnetization, and entanglement entropy of the two-qubit system. Based on previous works we derive an effective approximate Hamiltonian for the two-impurity SBM that preserves the excitation-number and thus facilitates the analytical treatment. In particular, it allows us to introduce non-Markovianity arising from delay-feedback effects in two distant emitters in the so-called ultrastrong coupling (USC) regime. We test our results with numerical simulations performed over a discretized circuit-QED model, finding perfect agreement with previous results, and showing interesting dynamical effects arising in ultrastrong waveguide QED with distant emitters. In particular, we revisit the Fermi two-atom problem showing that, in the USC regime, initial correlations yield two different evolutions for symmetric and antisymmetric states even before the emitters become causally connected. Finally, we demonstrate that the collective dynamics, e.g., superradiance or subradiance, are affected not only by the distance between emitters, but also by the coupling, due to significant frequency renormalization. This constitutes another dynamical consequence of the USC regime

Análisis de la implementación de los programas compensatorios del CONAFE en el estado de Nayarit, México

Las razones particulares que me motivaron a realizar esta reflexión y con esto establecer esta propuesta de trabajo es que viví en situación real dicha tarea, ya que en su momento fui asignado como el contralor social en el estado de Nayarit para los programas compensatorios del CONAFE y dicho papel lo desempeñé teniendo carencias, por lo cual no me permitían realizar mis labores como contralor, frustrando de esta manera el desempeño de los resultados esperados en oficinas centrales. Por lo cual, mediante el presente análisis de reporte de experiencia profesional, se obtendrá el conocimiento sobre la normatividad vigente del CONAFE, así como, un análisis de la guía operativa de los programas compensatorios, como también, conocer los objetivos del contralor social, con la finalidad de proponer estrategias para la inducción, aplicación y control de los recursos federales que se utilizan en dicho programa, como también, los presentes resultados beneficiarán a los niños, niñas y jóvenes que habitan en localidades rurales marginadas y dispersas en el estado de Nayarit, cuyas condiciones de vida se mejorarán, en razón de qué se ofrecerá mayor calidad en la educación inicial, preescolar, primaria y secundaria, lo cual ayudará a abatir los rezagos de educación, mejorando oportunidades de acceso y permanencia

QSPR calculation of normal boiling points of organic molecules based on the use of correlation weighting of atomic orbitals with extended connectivity of zero- and first-order graphs of atomic orbitals

We report the results of a calculation of the normal boiling points of a representative set of 200 organic molecules through the application of QSPR theory. For this purpose we have used a particular set of flexible molecular descriptors, the so called Correlation Weighting of Atomic Orbitals with Extended Connectivity of Zero- and First-Order Graphs of Atomic Orbitals. Although in general the results show suitable behavior to predict this physical chemistry property, the existence of some deviant behaviors points to a need to complement this index with some other sort of molecular descriptors. Some possible extensions of this study are discussed.SCOPU

High-Speed Rail Versus Air Transportation: Case Study of Madrid–Barcelona, Spain.

Travel time savings, better quality of the supplied services, greater comfort for the users, and improved accessibility are the main factors of success of High Speed Rail(HSR)links. This paper presents the results from a revealed and stated preference survey conducted to both HSR and air transport users in the Madrid Barcelona corridor. The data gathered from the stated preference survey was used to calibrate a modal choice model aiming at explaining competition between HSR and air transportation in the corridor. From the model, the authors obtain that prices and service frequency are the most important variables to compete with the other mode. In addition, they found that check-in and security controls at the airport are a crucial variable for the users in their modal choice. Other policies, such as the improvement of parking facilities at the train stations, play a secondary role

Estudio de la biocompatibilidad in vitro de polimeros metacrílicos derivados de pirrolidona-ina

Este estudio analiza la biocompatibilidad de nuevos biomateriales a base de hidrogeles metacrílicos como el poli-[metacrilato de 2-etil-(2-pirrolidona)] (PEPM) y la poli-[metacrilato de 2-etil-(2-pirrolidina)], en comparación con referentes comerciales tales como la poli-(vinil pirrolidona) (PVP) y la poli-(N-N´-dimetilacrilamida) (PDMA). Se utilizaron propiedades bioquímicas, mediante los ensayos de MTT y Alamar Blue, para conocer el efecto de citotoxicidad y proliferación en cultivo de fibroblastos (células VERO), sobre los biomateriales metacrílicos. Adicionalmente, por microscopía óptica y electrónica fueron analizados el grado de adhesión, morfología, muerte celular, proliferación, contracción celular, etc. Además se estudiaron las relaciones entre citotoxicidad y estructura química. En el MTT y en el análisis óptico se obtuvo baja citotoxicidad para PEPM y PVP, media en PEPyM y alta en PDMA. En el Alamar Blue y SEM se produjo una media proliferación-adhesión en PEPM y PEPyM, alta en PVP y muerte celular en PDMA. Sus apropiadas características físico-químicas y su aceptable grado de biocompatibilidad les hacen buenos candidatos en aplicaciones tales como lentes de contacto, sistemas de liberación de fármacos e ingeniería de tejidos.This study analyzed biocompatibility of new biomaterials based on the methacrylic hydrogels derived poly-[2-ethyl-(2-pyrrolidone) methacrylate] (PEPM) and poly-[2-ethyl-(2-pyrrolidine) methacrylate] (PEPyM), in comparison with references such as commercial poly-(vinyl pyrrolidone) (PVP) and poly-(N, N-dimethylacrylamide) (PDMA). The biochemical properties were used to know citotoxicity and proliferation effect over fibroblast culture (VERO cells) in contact with the methacrylic biomaterials, using MTT and Alamar Blue assays. Additionally, were analyzed adhesion grade, morphology, death cell presence, proliferation, cell contraction, etc, by optical and scanning electronic microscopy (SEM). The relationships between their chemical structures and cytotoxicity were studied. In MTT and optical analysis, low cytotoxicity was found for PEPM and PVP, medium in the case of PEPyM, and high for PDMA. In Alamar Blue and SEM, were produced a medium proliferation and adhesion rate for PEPM and PEPyM, high in PVP, and cellular death for PDMA. Their appropriates physico-chemical characteristics and approval biocompatibility grade make them good candidates in applications such as contact lenses, drug release systems and tissue engineering

Kinematics and Convergent Tectonics of the Northwestern South American Plate During the Cenozoic

The interaction of the northern Nazca and southwestern Caribbean oceanic plates with northwestern South America (NWSA) and the collision of the Panama-Choco arc (PCA) have significant implications on the evolution of the northern Andes. Based on a quantitative kinematic reconstruction of the Caribbean and Farallon/Farallon-derived plates, we reconstructed the subducting geometries beneath NWSA and the PCA accretion to the continent. The persistent northeastward migration of the Caribbean plate relative to NWSA in Cenozoic time caused the continuous northward advance of the Farallon-Caribbean plate boundary, which in turn resulted in its progressive concave trench bending against NWSA. The increasing complexity during the Paleogene included the onset of Caribbean shallow subduction, the PCA approaching the continent, and the forced shallow Farallon subduction that ended in the fragmentation of the Farallon Plate into the Nazca and Cocos plates and the Coiba and Malpelo microplates by the late Oligocene. The convergence tectonics after late Oligocene comprised the accretional process of the PCA to NWSA, which evolved from subduction erosion of the forearc to collisional tectonics by the middle Miocene, as well as changes of convergence angle and slab dip of the Farallon-derived plates, and the attachment of the Coiba and Malpelo microplates to the Nazca plate around 9 Ma, resulting in a change of convergence directions. During the Pliocene, the Nazca slab broke at 5.5°N, shaping the modern configuration. Overall, the proposed reconstruction is supported by geophysical data and is well correlated with the magmatic and deformation history of the northern Andes

Intelligence and video games: beyond “brain-games”

Video games are among the most popular leisure activities in current Western societies. Psychology research has shown correlations, at the latent level, between intelligence and video games ranging from 0.60 to 0.93. Here we analyze whether video games genre can account for this range of correlations by testing one hundred and thirty-four participants playing ten video games of different genres for iPad® and WiiU® (Art of Balance®, Blek, Crazy Pool, EDGE®, Hook, Rail Maze, SkyJump, Space Invaders, Splatoon® and Unpossible) within a controlled playing environment. Gaming performance was correlated with standard measures of fluid reasoning, visuospatial ability, and processing speed. Results revealed a correlation value of 0.79 between latent factors representing general intelligence (g) and video games general performance (gVG). This finding leads to conclude that: (1) performance intelligence tests and video games is supported by shared cognitive processes and (2) brain-games are not the only genre able to produce performance measures comparable to intelligence standardized tests. From a theoretical perspective, the observed result supports the principle of the indifference of the indicator that has been addressed in intelligence research across decade