Flavor changing Z' couplings at the LHC

Models with a non-universal Z' exhibit in general flavor changing neutral currents (FCNC) at tree-level. When the Z' couplings favor the third generation, flavor changing transitions of the form Z'tc and Z'tu could be large enough to be observable at the LHC. In this paper we explore this possibility using the associated production of a single top-quark with the Z' and find that integrated luminosities of a few hundred fb$^{-1}$ are necessary to probe the interesting region of parameter space.Comment: 12 LaTeX Pages, 10 EPS Figure

Addressing culture in the EFL classroom: A dialogic proposal built up through dialogism

Language teaching has gone from a linguistic centered approach towards a lingocultural experience in which learning a language goes hand in hand with the understanding of, not only the target culture but the learner’s own culture. This paper intends to describe and reflect upon a collaborative and dialogical experience carried out between two teachers of the Languages Program of Universidad de la Salle. The bilateral enrichment of such a pedagogical experience not only helped the teachers to improve their language teaching contexts but also prompted the construction of a theoretical proposal to enhance intercultural awareness and develop critical intercultural competence in FL learners

Prótesis de rodilla externa mecatrónica

Se diseña un mecanismo de articulación de rodilla para una prótesis externa, es decir el prototipo puede ser usado en personas con amputaciones del tipo transfemoral, con el fin de contribuir a la sociedad al brindar soluciones a favor de las personas con capacidades especiales. Se toma en consideración los aspectos más relevantes para el desarrollo de la marcha humana protésica normal como son: nivel de actividad física, medidas antropométricas, materiales adecuados para la construcción, estabilidad y confort entre otros. Luego de realizar un análisis extensivo y proceso de diseño y rediseño se construyó un prototipo funcional, que en el futuro podrá ser probado en personas que así lo requieran.Peer Reviewe

Bs−BˉsB_s-\bar B_s Mixing constraints on FCNC and a non-universal Z′Z^\prime

$B_s - \bar B_s$ mixing has been measured recently by D0 and CDF. The range predicted in the standard model is consistent with data. However, the standard model central values for $\Delta M_{B_s}$ and also $\Delta M_ {B_d}$ are away from the data which may be indications of new physics. Using the observed values of $\Delta M_{B_s}$ and $\Delta M_{B_d}$ we study general constraints on flavor changing $Z^\prime$ interactions. In models with non-universal $Z^\prime$ couplings we find that significant enhancements over the standard model are still possible in the rare decay modes $B\to X_s \tau^+ \tau^-$, $B\to X_s \nu \bar \nu$ and $B_s\to \tau^+ \tau^-$. Tree level $Z^\prime$ contributions to $K\to \pi \nu\bar \nu$ are now constrained to be very small, but one loop effects can still enhance the standard model rate by a factor of two.Comment: 16 pages, 7 figure

CP Violating Rate Difference Relations for B→PPB\to PP and B→PVB \to PV in Broken SU(3)

Within the standard model there exist certain relations between CP violating rate differences in B decays in the SU(3) limit. We study SU(3) breaking corrections to these relations in the case of charmless, hadronic, two body $B$ decays using the improved factorization model of Ref.\cite{3}. We consider the cases $B \to PP$ and $B \to PV$ for both $B_d$ and $B_s$ mesons. We present an estimate for $A_{CP}(\pi^- \pi^+)$ in terms of $A_{CP}(K^- \pi^+)$.Comment: Latex 13 pages, no figure

Evolution and interspecies transmission of canine distemper virus—an outlook of the diverse evolutionary landscapes of a multi-host virus

This article belongs to the Special Issue MorbillivirusesCanine distemper virus (CDV) is a worldwide distributed virus which belongs to the genus Morbillivirus within the Paramyxoviridae family. CDV spreads through the lymphatic, epithelial, and nervous systems of domestic dogs and wildlife, in at least six orders and over 20 families of mammals. Due to the high morbidity and mortality rates and broad host range, understanding the epidemiology of CDV is not only important for its control in domestic animals, but also for the development of reliable wildlife conservation strategies. The present review aims to give an outlook of the multiple evolutionary landscapes and factors involved in the transmission of CDV by including epidemiological data from multiple species in urban, wild and peri-urban settings, not only in domestic animal populations but at the wildlife interface. It is clear that different epidemiological scenarios can lead to the presence of CDV in wildlife even in the absence of infection in domestic populations, highlighting the role of CDV in different domestic or wild species without clinical signs of disease mainly acting as reservoirs (peridomestic and mesocarnivores) that are often found in peridomestic habits triggering CDV epidemics. Another scenario is driven by mutations, which generate genetic variation on which random drift and natural selection can act, shaping the genetic structure of CDV populations leading to some fitness compensations between hosts and driving the evolution of specialist and generalist traits in CDV populations. In this scenario, the highly variable protein hemagglutinin (H) determines the cellular and host tropism by binding to signaling lymphocytic activation molecule (SLAM) and nectin-4 receptors of the host; however, the multiple evolutionary events that may have facilitated CDV adaptation to different hosts must be evaluated by complete genome sequencing. This review is focused on the study of CDV interspecies transmission by examining molecular and epidemiological reports based on sequences of the hemagglutinin gene and the growing body of studies of the complete genome; emphasizing the importance of long-term multidisciplinary research that tracks CDV in the presence or absence of clinical signs in wild species, and helping to implement strategies to mitigate the infection. Integrated research incorporating the experience of wildlife managers, behavioral and conservation biologists, veterinarians, virologists, and immunologists (among other scientific areas) and the inclusion of several wild and domestic species is essential for understanding the intricate epidemiological dynamics of CDV in its multiple host infections

Large eddy simulation of partial cavitation around a 2D plane-convex hydrofoil

Investigations of attached partial cavitation are important because to prevent damages in hydrulic machinery and to reduce the costs. As expected computational fluid dynamics (CFD) methods have been developed for more than 40 years to understand this phenomenon and to improve the machinery designs, as pumps and hydraulic turbines. However, cavitation appears at high Reynolds numbers, so that, the traditional turbulence models Reynolds-averaged Navier-Stokes (RANS)Postprint (published version

Case based reasoning applied to medical diagnosis using multi-class classifier: A preliminary study

Case-based reasoning (CBR) is a process used for computer processing that tries to mimic the behavior of a human expert in making decisions regarding a subject and learn from the experience of past cases. CBR has demonstrated to be appropriate for working with unstructured domains data or difficult knowledge acquisition situations, such as medical diagnosis, where it is possible to identify diseases such as: cancer diagnosis, epilepsy prediction and appendicitis diagnosis. Some of the trends that may be developed for CBR in the health science are oriented to reduce the number of features in highly dimensional data. An important contribution may be the estimation of probabilities of belonging to each class for new cases. In this paper, in order to adequately represent the database and to avoid the inconveniences caused by the high dimensionality, noise and redundancy, a number of algorithms are used in the preprocessing stage for performing both variable selection and dimension reduction procedures. Also, a comparison of the performance of some representative multi-class classifiers is carried out to identify the most effective one to include within a CBR scheme. Particularly, four classification techniques and two reduction techniques are employed to make a comparative study of multiclass classifiers on CB