Lepton number violation in top quark and neutral B meson decays

Lepton number violation (LNV) can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |\Delta L|=2 decays in an scenario where a single heavy neutrino can enhance the amplitude via the resonant mechanism. Using current bounds on heavy neutrino mixings, the most optimistic branching ratios turn out to be at the level of 10^{-6} for \bar{B} -> D^+e^-e^-\pi^+ and t -> bl^+l^+W^- decays. Searches for these LNV decays at future facilities can provide complementary constraints on masses and mixings of Majorana neutrinos.Comment: 15 pages, 6 figures, "Added comments on sensitivities. Version accepted for publication

Collective Coordinates Theory for Discrete Soliton Ratchets in the sine-Gordon Model

A collective coordinate theory is develop for soliton ratchets in the damped discrete sine-Gordon model driven by a biharmonic force. An ansatz with two collective coordinates, namely the center and the width of the soliton, is assumed as an approximated solution of the discrete non-linear equation. The evolution of these two collective coordinates, obtained by means of the Generalized Travelling Wave Method, explains the mechanism underlying the soliton ratchet and captures qualitatively all the main features of this phenomenon. The theory accounts for the existence of a non-zero depinning threshold, the non-sinusoidal behaviour of the average velocity as a function of the difference phase between the harmonics of the driver, the non-monotonic dependence of the average velocity on the damping and the existence of non-transporting regimes beyond the depinning threshold. In particular it provides a good description of the intriguing and complex pattern of subspaces corresponding to different dynamical regimes in parameter space

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An approach to emotion recognition in single-channel EEG signals: a mother child interaction

In this work, we perform a first approach to emotion recognition from EEG single channel signals extracted in four (4) mother-child dyads experiment in developmental psychology -- Single channel EEG signals are analyzed and processed using several window sizes by performing a statistical analysis over features in the time and frequency domains -- Finally, a neural network obtained an average accuracy rate of 99% of classification in two emotional states such as happiness and sadness20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin

Energy Flow Puzzle of Soliton Ratchets

We study the mechanism of directed energy transport for soliton ratchets. The energy flow appears due to the progressive motion of a soliton (kink) which is an energy carrier. However, the energy current formed by internal system deformations (the total field momentum) is zero. We solve the underlying puzzle by showing that the energy flow is realized via an {\it inhomogeneous} energy exchange between the system and the external ac driving. Internal kink modes are unambiguously shown to be crucial for that transport process to take place. We also discuss effects of spatial discretization and combination of ac and dc external drivings.Comment: 4 pages, 3 figures, submitted to PR

Teor?as impl?citas sobre la ense?anza en los ingenieros de sistemas que se desempe?an como docentes en las universidades de la ciudad de Ibagu?

109 p. Recurso Electr?nicoEs com?n el ingreso a la docencia de profesionales con formaci?n diferente a la pedag?gica, para orientar cursos de ?ndole especialmente pr?ctica. Es el caso de la Ingenier?a de Sistemas, programa que requiere casi en su totalidad profesores con profesiones espec?ficas, sobre todo, como es de esperarse, ingenieros de sistemas. El ingreso a la profesi?n docente se da por variadas circunstancias, pero siempre conlleva responsabilidades comunes, sobre todo en el campo de la pedagog?a y la did?ctica, indispensables para el ?xito de la labor docente que afrontan estos profesionales. A partir de la pr?ctica docente de estos profesores, surgen problem?ticas asociadas de una manera u otra a su accionar en el aula de clase, como son la deserci?n y la mortalidad acad?mica, las cuales preocupan y exigen respuestas de las directivas de instituciones educativas en todo el mundo. Estas problem?ticas pueden ser abordadas para su estudio desde diferentes perspectivas, en el caso de esta investigaci?n se hace un aporte a este campo desde las Teor?as Impl?citas, planteadas magistralmente por Javier Marrero, y desarrolladas por muchos otros docentes e investigadores en todo el mundo. Se logr? para esta investigaci?n la vinculaci?n de un n?mero importante de Ingenieros de Sistemas que se desempe?an como docentes en diferentes universidades de la ciudad de Ibagu?, en Colombia, a los cuales se les aplic? instrumentos dise?ados para identificar estilos de ense?anza a partir de los cuales develar las teor?as que de forma impl?cita animan su labor docente. Gracias a estos instrumentos se logra concluir, entre otras cosas, que la labor docente de estos ingenieros est? fundamentada en unas teor?as sobre la ense?anza, especialmente tienen preponderancia las teor?as interpretativa y productiva de acuerdo a los aportes de Javier Marrero, pero adem?s que estas teor?as impl?citas son din?micas, se transforman constantemente, y que la principal fuerza transformadora es la propia iniciativa de los docentes quienes se preocupan por alcanzar la perfecci?n en su compromiso con el sistema educativo. Otra de las principales conclusiones de este trabajo, es que a diferencia de otras investigaciones aplicadas a profesionales de otras disciplinas, se encontr? que entre los ingenieros de sistemas es sobresaliente la congruencia entre lo que estos plantean y lo que aplican al respecto del estilo de ense?anza que prefieren a la hora de cumplir su labor docente.Professionals getting into teaching without teacher training is common, particularly into courses of practical nature. This is the case of the Systems Engineering program which requires almost entirely teachers with specific professions, especially, as expected, systems engineers. Entering into teaching is given by different circumstances, but always entails common responsibilities, particularly in the field of pedagogy and didactics, indispensable for the success of teaching that these professionals face. Teaching practices of these teachers, are associated, in one way or another, with problems related to their actions in the classroom, such as desertion and academic mortality, which require special care and policy responses from educational institutions around the world. Study of these issues can be addressed from different perspectives. In the case of this research, a contribution is made in this field from the Implicit Theories, masterfully raised by Javier Marrero, and developed by many other teachers and researchers worldwide. For this research was achieved the colaboration of a large number of systems engineers working as teachers in different Universities in the city of Ibagu?, Colombia,. Instruments designed to identify learning styles ere applied to these subjects leading us to unveil the theories that implicitly encourage their teaching. Thanks to these instruments is possible to conclude, among other things, that the teaching practices of these engineers is based on a theory about teaching with especial preponderance on the interpretative and productive theories developed by Javier Marrero. Also, these Implicit theories are dynamic, constantly transformed, and the main transforming power is the initiative of teachers who care for perfection in their commitment to the education system. Another of the main conclusions of this work is that, unlike other research applied to professionals from other disciplines, we found that among systems engineers there is a remarkable consistency between what they pose and what they apply on the teaching style they prefer in performing their teaching activities. Key words: Systems Engineering, teaching practice, implicit theories, teaching styles

On the existence of internal modes of sine-Gordon kinks

We study whether or not sine-Gordon kinks exhibit internal modes or ``quasimodes.'' By considering the response of the kinks to ac forces and initial distortions, we show that neither intrinsic internal modes nor ``quasimodes'' exist in contrast to previous reports. However, we do identify a different kind of internal mode bifurcating from the bottom edge of the phonon band which arises from the discretization of the system in the numerical simulations, thus confirming recent predictions.Comment: 4 pages, 2 figures, REVTeX, to appear as a Rapid Communication in Phys Rev E (July 1st

Behavior of liquid plugs at bifurcations in a microfluidic tree network

International audienceFlows in complex geometries, such as porous media or biological networks, often contain plugs of liquid flowing within air bubbles. These flows can be modeled in microfluidic devices in which the geometric complexity is well defined and controlled. We study the flow of wetting liquid plugs in a bifurcating network of micro-channels. In particular, we focus on the process by which the plugs divide as they pass each bifurcation. The key events are identified, corresponding to large modifications of the interface curvature, the formation of new interfaces, or the division of a single interface into two new ones. The timing of the different events and the amplitude of the curvature variations are analyzed in view of the design of an event-driven model of flow in branching micro-networks. They are found to collapse onto a master curve dictated by the network geometry. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739072

An?lisis de las pr?cticas pedag?gicas y su relaci?n con la calidad acad?mica de la educaci?n media en Nicanor Vel?squez Ortiz del municipio de Ambalema Tolima

79 p. Recurso Electr?nicoDebido a que las pr?cticas pedag?gicas son de suma importancia a nivel nacional e internacional en relaci?n con la calidad acad?mica y lo que respeta con las pruebas generales como son las pruebas pisa, las pruebas saber once en la educaci?n. Surge la importancia de esta investigaci?n despu?s de analizar la calidad acad?mica, en el cual el objetivo principal de esta investigaci?n es relacionar la influencia de las pr?cticas pedag?gicas en la calidad acad?mica de la instituci?n Nicanor Vel?squez Ortiz, adem?s identificar los factores que influye en el nivel acad?mico de educaci?n media de dicha instituci?n. La presente investigaci?n est? basada en un estudio de caso, teniendo en cuenta unas categor?as de investigaci?n (pertinencia, sistemas de evaluaci?n, pr?cticas pedagog?as, calidad acad?mica). Las t?cnicas para la recolecci?n de la informaci?n que se aplicaron son: entrevista a docentes de educaci?n media, testimonio focalizado a docentes y grupo focal con estudiantes de educaci?n media; los instrumentos para estas t?cnicas de recolecci?n de datos son cuestionarios. La poblaci?n de investigaci?n es la instituci?n educativa Nicanor Vel?squez Ortiz de Ambalema Tolima y la muestra es la educaci?n media de dicha instituci?n, con 85 participantes entre los 14 y 19 a?os y 6 docentes de entre 40 y 56 a?os .Como resultados, se observa que la calidad acad?mica en educaci?n media en esta instituci?n es baja debido a distintos factores como : algunos docentes no aplican sus pr?cticas pedag?gicas de acuerdo al enfoque de la instituci?n, falta de pertinencia por parte de los educandos debido a que no cuentan con h?bitos de estudio estructurados, falta de acompa?amiento por parte de los padres, la infraestructura no es la m?s adecuada ya que se presentan altas temperaturas en el municipio, no se cuenta con ventiladores adecuados, se presenta hacinamiento en las aulas de clase. En el caso de esta investigaci?n es evidente que la problem?tica en torno a la calidad acad?mica podr?a cambiar si lo docentes se comprometen de manera responsable a indagar en busca de la apropiaci?n del enfoque pedag?gico de la instituci?n y as? direccionar las pr?cticas pedag?gicas a dicho enfoque, en vista de que siempre ha existido este nivel en la instituci?n, con respecto a las pruebas saber once presentadas hace varios donde estas vienen presentado niveles desfavorables para el proceso educativo que lleva a cabo la instituci?n.Because teaching practices are vital to national and international level in relation to the academic quality and respecting the general tests such as PISA tests are the tests to know eleven education. It arises the importance of this research math teacher of the institution after analyzing the academic quality in which the main objective of this research is to investigate the influence of pedagogical practices in the academic quality of the institution Nicanor Velasquez Ortiz also identify factors influencing the academic level of secondary education in that institution. This research is based on a case study, considering a research categories (relevance, evaluation systems, practical teaching methods, academic quality). The techniques for gathering information were applied are: interview to middle school teachers, teachers and testimony focused focus group with high school students; instruments for these techniques of data collection are questionnaires. The research population is the educational institution Ambalema Nicanor Velasquez Ortiz of Tolima, the sample is the average education of the institution, with 85 participants between 14 and 19 years and 6 teachers aged between 40 and 56 years .As results, it appears that academic quality in secondary education at this institution is low due to several factors: some teachers do not apply their teaching according to the approach of the institution, irrelevance by the students because they do not have study habits structured, lack of support from parents, the infrastructure is not adequate since high temperatures in the city are presented, do not have adequate fans, overcrowding occurs in classrooms and natural resources are often lacking. In the case of this research it is evident that there is academic quality if managed to break the barrier that has always existed in the institution with respect to the evidence presented to know eleven years ago and has been presented this low academic level. Teachers It is recommended to investigate the pedagogical approach of the institution and thus address the pedagogical approach to such practices. Key Works: Academic quality, pedagogical practices, conceptions