Phase response to stimuli : the case of excitable systems

In this thesis we extend the idea of Phase Resetting Function (PRF) to the case of excitable systems where there are no sustained oscillations. We use theoretical results to justify the definition of an asymptotic phase and use normal form transformations and numerical integration for the computations. We apply the method to two simple example and examine the results for several sets of parameters

Health and heating in the city of Temuco (Chile). Monetary savings of replacing biomass with PV system in the residential sector

The paper conducts a comprehensive analysis of replacing residential use of wood burning stoves for heating with photovoltaic systems for the generation of electricity using storage batteries (PV + storage systems). The research focuses on the city of Temuco (Southern Chile) as a case study, since this city has a high use of firewood for heating (80% of households) and also because this city has been declared by authorities as an area saturated with suspended particles. The total cost corresponds to the acquisition of systems. The reduction of monetary value of the impact of polluting emissions, resulting from the combustion of firewood, on health and traffic accidents is calculated. The interactive tool GDB Compare has been used to calculate the impact of pollution on health both in terms of attributable deaths and disability-adjusted life years. The monetary value of the impact on health has been calculated using two alternative approaches: the value of statistical life and the human capital approach. To identify firewood use requirements, heating degree–days has been used for temperatures ≤15 °C and ≤18 °C. The emissions avoided calculations have been refined, including emissions associated with the manufacture and transport of systems through the life cycle analysis. For all scenarios, the main results show that the savings outweigh the costs

Empirical evidence on return migration from Spain to Ecuador. Discourse, myth or reality?

Through this article we analyze in depth the issue of return in international migration. To do this, it has used different statistical sources and in-depth interviews in order to quantify the magnitude of the return of the Ecuadorian origin resident in Spain. We based on this premise, we note that the phenomenon of return to Ecuador has grown significantly in recent years due to the economic crisis in Spain, but has not been on a massive scale. This statement raises the need to reflect on return policies that have been implemented to the present and what should be the priorities of the origin and destination country when it comes to protecting and providing support to international migrants

Seismic assessment of the masonry buildings typical of Barcelona using the Risk-UE methodology

En este trabajo se realiza un estudio para evaluar la vulnerabilidad y el daño sísmico en edificios de obra de fábrica de ladrillo no reforzada. Se han elegido 3 modelos de edificios representativos del distrito Eixample de Barcelona. El análisis de la vulnerabilidad sísmica se lleva a cabo mediante la metodología Risk-UE. La demanda sísmica se define a partir del espectro de proyecto elástico con 5% de amortiguamiento, definido, en este caso, por el Eurocódigo 8. Las curvas de fragilidad se obtienen a partir de un análisis no lineal, teniendo en cuenta los espectros de capacidad. El daño sísmico esperado se consigue con las matrices de probabilidad de daño, las cuales indican la probabilidad de ocurrencia de un estado de daño para una demanda sísmica específica. La modelización de los edificios se realiza con el programa TreMuri mediante un modelo de macroelementos, el cual representa las paredes de los edificios. Los edificios aquí analizados son reales y se dispuso de planos e informes específicos. Los resultados obtenidos muestran una vulnerabilidad importante en este tipo de edificios, teniendo en cuenta el escenario sísmico considerado el daño sísmico esperado es alto.In this work, a study about the vulnerability and seismic damage of unreinforced masonry buildings is carried out. Three models of buildings representatives of the Eixample district of Barcelona have been chosen. The seismic vulnerability is evaluated by means of the Risk-UE methodology. The seismic demand is described by elastic project spectrum, in this case, defined by the Eurocode 8. Fragility curves are obtained from a nonlinear analysis, considering the capacity spectra. Expected seismic damage is gotten with the damage probability matrices, which indicate the occurrence probability of a damage state for a seismic demand given. The analysis of the buildings has been performed by TreMuri program by means of a macroelements model, which represents of a whole masonry panel. The buildings, here, analyzed are real and detailed structural drawings and reports have been used to model them. The results shown a considerable vulnerability in this type of buildings, therefore, in spite of the seismic hazard the expected seismic risk is significant.Peer Reviewe

Splitting of separatrices for rapid degenerate perturbations of the classical pendulum

In this work we study the splitting distance of a rapidly perturbed pendulum $H(x,y,t)=\frac{1}{2}y^2+(\cos(x)-1)+\mu(\cos(x)-1)g\left(\frac{t}{\varepsilon}\right)$ with $g(\tau)=\sum_{|k|>1}g^{[k]}e^{ik\tau}$ a $2\pi$-periodic function and $\mu,\varepsilon \ll 1$. Systems of this kind undergo exponentially small splitting and, when $\mu\ll 1$, it is known that the Melnikov function actually gives an asymptotic expression for the splitting function provided $g^{[\pm 1]}\neq 0$. Our study focuses on the case $g^{[\pm 1]}=0$ and it is motivated by two main reasons. On the one hand the general understanding of the splitting, as current results fail for a perturbation as simple as $g(\tau)=\cos(5\tau)+\cos(4\tau)+\cos(3\tau)$. On the other hand, a study of the splitting of invariant manifolds of tori of rational frequency $p/q$ in Arnold's original model for diffusion leads to the consideration of pendulum-like Hamiltonians with $g(\tau)=\sin\left(p\cdot\frac{t}{\varepsilon}\right)+\cos\left(q\cdot\frac{t}{\varepsilon}\right),$ where, for most $p, q\in\mathbb{Z}$ the perturbation satisfies $g^{[\pm 1]}\neq 0$. As expected, the Melnikov function is not a correct approximation for the splitting in this case. To tackle the problem we use a splitting formula based on the solutions of the so-called inner equation and make use of the Hamilton-Jacobi formalism. The leading exponentially small term appears at order $\mu^n$, where $n$ is an integer determined exclusively by the harmonics of the perturbation. We also provide an algorithm to compute it

Building Resilience with Aerobic Exercise: Role of FKBP5.

Both preclinical and clinical studies have pointed that aerobic exercise, at moderate doses, is beneficial at all stages of life by promoting a range of physiological and neuroplastic adaptations that reduce the anxiety response. Previous research about this topic have repeatedly described how the regular practice of aerobic exercise induces a positive regulation of neuroplasticity and neurogenesis-related genes, as well as a better control of the HPA axis function. However, limited progress has been carried out in the integration of neuroendocrine and neuroplastic changes, as well as in introducing new factors to understand how aerobic exercise can promote resilience to future stressful conditions. Resilience is defined as the ability to adapt to stress while maintaining healthy mental and physical performance. Consistent findings point to an important role of FKBP5, the gene expressing FK506-binding protein 51 (FKBP51), as a strong inhibitor of the glucocorticoid receptor (GR), and thus, an important regulator of the stress response. We propose that aerobic exercise could contribute to modulate FKBP5 activity acting as a potential therapeutic approach for mood disorders. In this sense, aerobic exercise is well known for increasing the growth factor BDNF, which by downstream pathways could affect the FKBP5 activity. Therefore, our manuscript has the aim of analyzing how FKBP5 could constitute a promising target of aerobic exercise promoting resilient-related phenotypes.pre-print346 K

Adult hippocampal neurogenesis and cognitive aging

Aging is a normal developmental process associated with neurobiological changes leading to cognitive alterations with preserved, impaired, and enhanced functions. Evidence from animal and human studies is reviewed to explore the potential role of hippocampal plasticity on age-related cognitive changes with special attention to adult hippocampal neurogenesis. Results from lesion and stimulation strategies, as well as correlation data, support either a direct or modulatory role for adult newborn neurons in cognition at advanced ages. Further research on this topic may help to develop new treatments and to improve the quality of life of older people

Fundamentos de la biopsia del ganglio centinela en el cáncer de mama

La linfadenectomía axilar es el método clásico para informarnos del estado de los ganglios axilares en el cáncer de mama. Sin embargo, al incorporarse el screenning mamográfico, los tumores diagnosticados en la actualidad son de tamaño reducido. Por lo tanto, el porcentaje de pacientes en las cuales esperamos que exista afectación axilar es muy bajo en la actualidad. La linfadenectomía axilar no está exenta de morbilidad; afecta al 80% de las pacientes sometidas a resección axilar niveles I y II. En el caso de que exista enfermedad a nivel axilar, esta morbilidad es aceptable y se compensa por el beneficio que la paciente obtiene al reducirse la masa tumoral; no obstante, en los casos en los que no existe afectación de los ganglios axilares esta morbilidad es inaceptable. La biopsia del ganglio centinela permite la resección y estudio de un único ganglio axilar con un mínimo porcentaje de falsos negativos, y una morbilidad prácticamente inexistente. El estudio sobre el ganglio centinela es más exacto y meticuloso, constituyendo en la actualidad la técnica quirúrgica de elección en pacientes con tumores menores de 3 cm y sin afectación axilar clínica.Axillary lymph node dissection is the gold standard for detecting axillary disease in breast cancer. Node status remains the most important prognostic factor, and is an important information to make decisions over further treatment. However, both the morbidity associated to this technique, and the fact that, due to mammografic screening, most of the cancer cases nowadays are early cancers that have no axillary metastases, have encouraged investigations towards new surgical approaches. Sentinel node biopsy has been recognized to detect any axillary disease with minimal morbidity and false-negative rates. This technique is routinely indicated for tumors below 3 cm in size, without clinical axillary disease

L1 use for classroom management purposes in EFL chilean contex

Tesis (Profesor de Inglés para la Enseñanza Básica y Media y al grado académico de Licenciado en Educación)The current study investigated the purposes of the L1 use in the L2 classes for classroom management. The aims of this research were to identify the uses of the L1 in the L2 class, also to find out teachers’ purposes for the use of the L1 in the L2 classroom, and finally to determine in which instances of L1 use are effective for classroom management. The qualitative study was conducted in a public school in the south part of Santiago de Chile. Four in-service teachers (two from elementary and two from secondary levels) participated in the investigation. The four participants’ lessons were audio recorded and field notes were taken. Then, four interviews were conducted using the method of stimulated recall interviews. The results suggest that the L1 is used mainly in a conscious manner for classroom management purposes such as reduce disruptions, give instructions, and to create a good relationship between teacher and students. Moreover, two of the four teachers find out that the use of the L1 in their English lessons was effective for classroom management purposes. We wrap up the study with pedagogical implication and suggestions for further research in this field.El presente estudio tiene como objetivo investigar los propósitos del uso de L1 en las clases de L2 para el manejo de la clase. Según el contexto educativo chileno, el propósito de esta investigación fue determinar cuán efectivo es el uso de la lengua materna en las lecciones de inglés. El estudio cualitativo se realizó en una escuela pública en la zona sur de Santiago de Chile. Cuatro maestros en servicio (dos de primaria y dos de secundaria) participaron en la investigación. Las lecciones de los cuatro participantes fueron grabadas en audio a través de notas de campo para luego ser entrevistadas usando el método de entrevistas estimuladas por el recuerdo. Los resultados sugieren que el L1 se usa principalmente de manera consciente para fines de manejo de la clase, como reducir las interrupciones, dar instrucciones y crear una buena relación entre el maestro y los estudiantes. Además, uno de los cuatro profesores descubrió que el uso de L1 en sus clases de Inglés era efectivo con propósito de manejo de la clase. Concluimos el estudio con implicaciones pedagógicas y sugerencias para futuras investigaciones en este campo

Environmental enrichment results in both brain connectivity efficiency and selective improvement in different behavioral tasks

Exposure to environmental enrichment (EE) has been a useful model for studying the effects of experience on brain plasticity, but to date, few is known about the impact of this condition on the brain functional networks that probably underlies the multiple behavioral improvements. Hence, we assessed the effect of an EE protocol in adult Wistar rats on the performance in several behavioral tasks testing different domains (Open field (OP): locomotor activity; Elevated-zero maze (EZM): anxiety-related behaviors; 5-choice serial reaction time task (5-CSRTT): attentional processes; 4-arm radial water maze (4-RAWM): spatial memory) in order to check its effectiveness in a wide range of functions. After this, we analyzed the functional brain connectivity underlying each experimental condition through cytochrome C oxidase (COx) histochemistry. Our EE protocol reduced both locomotor activity in the OP and anxiety-related behaviors in the EZM. On the other hand, enriched rats showed more accuracy in the 4-RAWM, whereas 5-CSRTT performance was not significantly ameliorated by EE condition. In relation to COx functional connectivity, we found that EE reduced the number of strong positive correlations both in basal and training conditions, suggesting a modulating effect on specific brain connections. Our results suggest that EE seems to have a selective effect on specific brain regions, such as prefrontal cortex and hippocampus, leading to a more efficient brain connectivity.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PPIT.UMA.B1.2017/3