Modelling biological invasions: individual to population scales at interfaces

Extracting the population level behaviour of biological systems from that of the individual is critical in understanding dynamics across multiple scales and thus has been the subject of numerous investigations. Here, the influence of spatial heterogeneity in such contexts is explored for interfaces with a separation of the length scales characterising the individual and the interface, a situation that can arise in applications involving cellular modelling. As an illustrative example, we consider cell movement between white and grey matter in the brain which may be relevant in considering the invasive dynamics of glioma. We show that while one can safely neglect intrinsic noise, at least when considering glioma cell invasion, profound differences in population behaviours emerge in the presence of interfaces with only subtle alterations in the dynamics at the individual level. Transport driven by local cell sensing generates predictions of cell accumulations along interfaces where cell motility changes. This behaviour is not predicted with the commonly used Fickian diffusion transport model, but can be extracted from preliminary observations of specific cell lines in recent, novel, cryo-imaging. Consequently, these findings suggest a need to consider the impact of individual behaviour, spatial heterogeneity and especially interfaces in experimental and modelling frameworks of cellular dynamics, for instance in the characterisation of glioma cell motility

Giant magnetoimpedance of FeNi-based nanostructures deposited onto glass and flexible substrates

This work was supported in part by the Basque Government through the Actimat Project under Grant IE13-380

Flexible magnetoelectronics: some aspects of the development of hibrid thin film structures

This work was developed under support of the “Laboratory of Physical Sensoric” project of Ural Federal University and ACTIMAT-ETORTEK grant of UPV-EHU and The Basque Country Government

Laser tweezers for atomic solitons

We describe a controllable and precise laser tweezers for Bose-Einstein condensates of ultracold atomic gases. In our configuration, a laser beam is used to locally modify the sign of the scattering length in the vicinity of a trapped BEC. The induced attractive interactions between atoms allow to extract and transport a controllable number of atoms. We analyze, through numerical simulations, the number of emitted atoms as a function of the width and intensity of the outcoupling beam. We also study different configurations of our system, as the use of moving beams. The main advantage of using the control laser beam to modify the nonlinear interactions in comparison to the usual way of inducing optical forces, i.e. through linear trapping potentials, is to improve the controllability of the outcoupled solitary wave-packet, which opens new possibilities for engineering macroscopic quantum states.Comment: 6 pages, 7 figure

Lie symmetries and solitons in nonlinear systems with spatially inhomogeneous nonlinearities

Using Lie group theory and canonical transformations we construct explicit solutions of nonlinear Schrodinger equations with spatially inhomogeneous nonlinearities. We present the general theory, use it to show that localized nonlinearities can support bound states with an arbitrary number solitons and discuss other applications of interest to the field of nonlinear matter waves

Symbiotic Solitons in Heteronuclear Multicomponent Bose-Einstein condensates

We show that bright solitons exist in quasi-one dimensional heteronuclear multicomponent Bose-Einstein condensates with repulsive self-interaction and attractive inter-species interaction. They are remarkably robust to perturbations of initial data and collisions and can be generated by the mechanism of modulational instability. Some possibilities for control and the behavior of the system in three dimensions are also discussed

Solitary Waves Under the Competition of Linear and Nonlinear Periodic Potentials

In this paper, we study the competition of linear and nonlinear lattices and its effects on the stability and dynamics of bright solitary waves. We consider both lattices in a perturbative framework, whereby the technique of Hamiltonian perturbation theory can be used to obtain information about the existence of solutions, and the same approach, as well as eigenvalue count considerations, can be used to obtained detailed conditions about their linear stability. We find that the analytical results are in very good agreement with our numerical findings and can also be used to predict features of the dynamical evolution of such solutions.Comment: 13 pages, 4 figure

Drogodependencias: XX Curso de Actualización para Postgraduados en Farmacia

El consumo de drogas es un fenómeno multicausal en el que incide una serie de factores del ámbito personal, familiar, social, y cultural. En los últimos años, asistimos a cambios tanto en la oferta de drogas como en los patrones de consumo. Así, mientras en los años 80 y primeros 90 la droga emblemática era la heroína, hoy en día su consumo se ha estabilizado, e incluso ha disminuido. Las nuevas formas de estar en sociedad afectan a grupos de jóvenes aceptablemente integrados en su medio familiar y social. A día de hoy, debe considerarse el consumo de otras drogas, fundamentalmente las llamadas drogas de síntesis, y la adopción de nuevos patrones en el consumo de algunas ya establecidas, como es el alcohol. En este marco se está haciendo frente al fenómeno del consumo de drogas desde diferentes perspectivas que se extienden desde la investigación científica hasta la prevención, la reducción de daños y la asistencia al drogodependiente. Entre las estrategias del nuevo Plan Nacional Sobre Drogas (PND) destaca la de normalizar las redes asistenciales a drogodependientes, integrándolas de forma coordinada en los sistemas públicos de salud y sistemas sociales. Se pretende que los diferentes recursos que formen parte del denominado sistema de asistencia e integración social de drogodependientes se caractericen por su profesionalización, interdisciplinariedad y fácil accesibilidad. En este sentido, hay que destacar la participación activa de algunos profesionales farmacéuticos en distintos programas de actuación, prevención y reducción de daños producidos por drogas. Por otra parte, se están realizando esfuerzos importantes en la investigación básica y clínica dirigidos a desentrañar los mecanismos que operan en la adicción a drogas. Los capítulos que componen este texto son el resultado del trabajo coordinado entre investigadores, docentes, farmacéuticos comunitarios, psicólogos, psiquiatras y otros profesionales implicados en la problemática de las drogodependencias. Su lectura permitirá conocer la actual situación respecto al consumo de drogas, los mecanismos neurobiológicos implicados en la drogadicción, la farmacología y la toxicología de las diferentes drogas, los riesgos asociados a su consumo, y los recursos disponibles que atienden a la población drogodependiente. Agradecemos la participación de los profesionales que asisten desde diferentes ámbitos a las personas afectadas directa o indirectamente por los problemas derivados del consumo de drogas, que ha hecho posible integrar aspectos básicos y prácticos de un tema tan complejo como es el de las drogodependencias

Geometria konplexuko pieza baten mekanizazio-estrategiak CAM bidez

In this work, knee prosthesis manufacturing process using CO2 cooling is described. It is necessary to use 5 continuous axis milling in order to manufacture this complex geometry. However, surfaces complexity and material (titanium) low machinability characteristics present a challenge for manufacturers. In this case, process operations and machining parameters for this component manufacturing are specified. Besides, virtual verification of machining process is also performed in order to avoid collisions. Moreover, cooling is a key factor in this case regarding medical components cleaning specifications. Traditional coolants are replaced by CO2 cooling.; Honako lan honetan belaun-protesiko osagarrien fabrikazioa azaltzen da CO2 hozgarri kriogenikoa erabiliz. Osagarrien konplexutasuna dela eta, beharrezkoa da 5-ardatzen interpolazioa gauzatzea fresaketa-eragiketetan. Gainazalen konplexutasun horrek eta materialaren (titanioaren) mekanizagarritasun baxuak mekanizazio-erronka berriak sortzen dituzte. Kasu honetan, osagarrien fabrikaziorako erabilitako mekanizazio-estrategiak eta mekanizazio-aldagaiak deskribatzen dira. Gainera, mekanizazioan ager daitezkeen talkak saihesteko, egiaztatze birtuala erabili da. Horrez gain, hozketa faktore garrantzitsu bat da osagai medikoen garbitasuneko beharrizanei dagokienez. Ohiko hozte-teknikak CO2 hozgarri kriogenikoarekin ordeztu dira

Solitary waves for linearly coupled nonlinear Schrodinger equations with inhomogeneous coefficients

Motivated by the study of matter waves in Bose-Einstein condensates and coupled nonlinear optical systems, we study a system of two coupled nonlinear Schrodinger equations with inhomogeneous parameters, including a linear coupling. For that system we prove the existence of two different kinds of homoclinic solutions to the origin describing solitary waves of physical relevance. We use a Krasnoselskii fixed point theorem together with a suitable compactness criterion.Comment: 16 page