Dynamics of interplate domain in subduction zones: influence of rheological parameters and subducting plate age

The properties of the subduction interplate domain are likely to affect not only the seismogenic potential of the subduction area but also the overall subduction process, as it influences its viability. Numerical simulations are performed to model the long-term equilibrium state of the subduction interplate when the diving lithosphere interacts with both the overriding plate and the surrounding convective mantle. The thermomechanical model combines a non-Newtonian viscous rheology and a pseudo-brittle rheology. Rock strength here depends on depth, temperature and stress, for both oceanic crust and mantle rocks. I study the evolution through time of, on one hand, the brittle-ductile transition (BDT) depth, <i>z</i><sub>BDT</sub>, and, on the other hand, of the kinematic decoupling depth, <i>z</i><sub>dec</sub>, simulated along the subduction interplate. The results show that both a high friction and a low ductile strength at the asthenospheric wedge tip shallow <i>z</i><sub>BDT</sub>. The influence of the weak material activation energy is of second order but not negligible. <i>z</i><sub>BDT</sub> becomes dependent on the ductile strength increase with depth (activation volume) if the BDT occurs at the interplate decoupling depth. Regarding the interplate decoupling depth, it is shallowed (1) significantly if mantle viscosity at asthenospheric wedge tip is low, (2) if the difference in mantle and interplate activation energy is weak, and (3) if the activation volume is increased. Very low friction coefficients and/or low asthenospheric viscosities promote <i>z</i><sub>BDT</sub> = <i>z</i><sub>dec</sub>. I then present how the subducting lithosphere age affects the brittle-ductile transition depth and the kinematic decoupling depth in this model. Simulations show that a rheological model in which the respective activation energies of mantle and interplate material are too close hinders the mechanical decoupling at the down-dip extent of the interplate, and eventually jams the subduction process during incipient subduction of a young (20-Myr-old) and soft lithosphere under a thick upper plate. Finally, both the BDT depth and the decoupling depth are a function of the subducting plate age, but are not influenced in the same fashion: cool and old subducting plates deepen the BDT but shallow the interplate decoupling depth. Even if BDT and kinematic decoupling are intrinsically related to different mechanisms of deformation, this work shows that they are able to interact closely. Comparison between modelling results and observations suggests a minimum friction coefficient of 0.045 for the interplate plane, even 0.069 in some cases, to model realistic BDT depths. The modelled <i>z</i><sub>dec</sub> is a bit deeper than suggested by geophysical observations. Eventually, the better way to improve the adjustment to observations may rely on a moderate to strong asthenosphere viscosity reduction in the metasomatised mantle wedge

Language Learning Guide Mobile Application

While traveling around the world, a lack of common language is often encountered. This can be a reason of not truly experiencing the country and the people that one is visiting. Thus, knowing even just a little of the local language will be a great advantage for any foreigner visiting or staying in another country. This project focuses on developing a mobile application that would aid any traveller or foreigner here in Malaysia in learning to converse in the local language for a better stay. This project also attempts to find the effective, efficient and interesting ways to learn a language. It is focused in providing the user the basic conversations that a foreigner will mostly/likely encounter while visiting or staying in Malaysia. The application is for foreigners who can speak English and is trying to learn Bahasa Malaysia. The android platform is chosen for the development of the application and coding with Java and Eclipse were used. The research and survey done resulted in the findings that using visual-audio sensory and interactive techniques will provide a more engaging and thus a more effective way of learning. With this implemented in the application, results of the user acceptance test showed that with the mobile application, an increase of the competency of the users’ Bahasa Malaysia speaking skills is observed

Estudo de idoneidade de diferentes linguaxes de programación na aprendizaxe en Programación do Grao de Enxeñaría Informática

[Resumo] A materia de Programación forma parte do módulo de formación básica do Grao en Informática, o obxectivo desta materia é ensinar ao alumno a crear modelos computacionais de problemas do mundo real, a realización desta labor faise empregando unha linguaxe de programación. A linguaxe de programación empregada na materia para ensinar os alumnos é un elemento fundamental e crítico, xa que dependendo das súas características vai ser máis doado ou complicado acadar as competencias para o alumno: detección de erros, escritura dos programas, entorno de desenvolvemento (IDE), ... Unha mostra disto é que se emprega a mesma linguaxe desde a creación da Facultade de Informática (FIC). Está non é un tarefa trivial debido a que non tódalas linguaxes están deseñadas seguindo o mesmo paradigma de programación, algunhas son case experimentais mentres outras son de uso case exclusivamente comercial, hai linguaxes que non teñen compilador “propio”, ... Neste traballo se presentan o resultado da análise de diferentes linguaxes que compren coas características necesarias, como se indicou anteriormente, para o seu uso na docencia da materia, valorando a súa idoneidade nas características máis importantes desde un punto de vista docente. As linguaxes que observouse que as cumprían foron: C/C++, C#, Python, Java, Ada, Go, Dart, Pascal, Fortran, Haskell, Scala, Nim, D e Kotlin

Interaction of Leishmania donovani promastigotes with mouse peritoneal exudate cells under the influence of the Chymotripsine

Se hace un estudio de la interacción de promastigotes de Leishmania donovani con células de exudado peritoneal de ratón (c e p) mediante la influencia de la quimotripsina. La adhesión de los promastigotes a las c e p fue terminal y marginal, y en observaciones hechas a partir de los 10 minutos de enfrentamiento, esta adhesión fue nula hasta los 30 minutos en el grupo tratado, y sólo a las das horas hubo un pequeño incremento (2.4%) con respecto al control. Se observa marcada disminución en todos los parámetro medidos, tales como enlace, penetración, multiplicación intracelular, división de formas flageladas, en el grupo tratado. La quimotripsina favorece la formación de formas intermedias flageladas, heciendose el parásito piriforme y esférico, apareciendo una forma aberrante de extremo anterior cilindrico que semeja a una forma coanoflagelada. Se sospecha que la enzima reduce efectivamente fragmentos proteicos o péptidos, los cuales pueden haber sido tan pequeños como para esconder a otros ligandos relacionados con la adhesión macrófago-parásito.The interaction of promastigotes of Leishmania donovani with mouse peritoneal exudate cells (cep) under the influence of Chymotripsine was studied. The promastigote adhered to the cep terminally and marginally. At 10-30 minutes postchallange, adhesion was absent in the treated group, and only after two hours was there any adhesión (24% in comparison with the controls). The experimental group was markedly deficient in all the parameters of activity measured: attachment, penetration, intracellular multiplication and division of flagellates forms in comparison to controls. The Chymotripsine favored the development of intermediate flagellates forms, these being spheroid or pyriform, with example of an aberrant form having the anterior end cylindrical similar to a choanoflagellate. It is suspected that the Chymotripsine effectively reduces protein or peptide fragments; these may have been so small as to conceal other ligands associated with macrophage-parasite adhesion

Small-scale convection in a plume-fed low-viscosity layer beneath a moving plate

Two-dimensional simulations using a thermomechanical model based on a finite-difference method on a staggered grid and a marker in cell method are performed to study the plume-lithosphere interaction beneath moving plates. The plate and the convective mantle are modelled as a homogeneous peridotite with a Newtonian temperature- and pressure-dependent viscosity. A constant velocity, ranging from 5 to 12.5 cm yr−1, is imposed at the top of the plate. Plumes are generated by imposing a thermal anomaly of 150 to 350 K on a 50 km wide domain at the base of the model (700 km depth); the plate atop this thermal anomaly is 40 Myr old. We analyse (1) the kinematics of the plume as it impacts the moving plate, (2) the dynamics of time-dependent small-scale convection (SSC) instabilities developing in the low-viscosity layer formed by spreading of hot plume material at the base of the lithosphere and (3) the resulting thermal rejuvenation of the lithosphere. The spreading of the plume material at the base of the lithosphere, characterized by the ratio between the maximum down- and upstream horizontal (dimensionless) velocities in the plume-fed sublithospheric layer, Peup/Pedown depends on the ratio between the maximum plume upwelling velocity and the plate velocity, Peplume/Peplate. For fast plate velocities and sluggish plumes (low Peplume/Peplate), plate motion drags most plume material and downstream flow is dominant. As Peplume/Peplate increases, an increasing part of the plume material flows upstream. SSC systematically develops in the plume-fed sublithospheric layer, downstream from the plume. Onset time of SSC decreases with the Rayleigh number. For vigorous plumes, it does not depend on plate velocity. For more sluggish plumes, however, variations in the plume spreading behaviour at the base of the lithosphere result in a decrease in the onset time of SSCs with increasing plate velocity. In any case, SSC results in uplift of the isotherm 1573 K by up to 20 km relative to its initial equilibrium depth at the impact poin

An Analytical and Descriptive Assessment of Michael Fullan's Scholarship on Educational Change

Thesis advisor: Robert J. StarrattThis thesis is a descriptive and analytical study of the complete works of Michael Fullan as a scholar of educational change. Fullan is one of the foremost individuals who have helped established the field of educational change and who continues to push the field forward. This dissertation investigates, articulates and interrogates the intellectual and strategic contributions of Fullan in the scholarly field of educational change. This is a critical description and examination of the historical events and trends that influenced his research and to which he was responding. It provides insight into a significant area of practice and research in educational administration by looking at the development of a field through the intellectual contributions of one of its most important authorities. The main purpose is to highlight the development and cogency of Fullan's ideas in the field of educational change through an examination and exploration of his intellectual underpinnings. This study was grounded in the qualitative research tradition, particularly rooted in a conceptual framework of hermeneutics. The task was to search for an understanding rather than explanation and for interpretation rather than prediction. Thus, in this study the researcher was the primary instrument for data collection and analysis. Data was using collected various artifacts, namely: books, journal articles, scholarly papers, technical reports, conference papers, dissertations about Fullan, web-site reports and/or papers, newspaper articles and publicity material. More specifically, Fullan's writings were primarily accessed through various venues: the internet (especially his website: http://www.michaelfullan.ca/), college libraries and professors who use his books. One person-to-person interview was conducted to clarify. Data was critically analyzed and reported thematically and chronologically in order to position Fullan's works within those historical periods and to identify the development and evolution of his theory of change. Findings indicate several periods of education reform: innovation and diffusion, school effectiveness and school improvement, restructuring and reculturing, large-scale reform and post-standardization. Fullan's assessments of each period revealed that he has been more influential in the large-scale reform period than the others. Themes unfolding highlighted the importance of stakeholders (students, teachers, principals, parents and community, district administrators, consultants) and concepts (process, objective and subjective assumptions, moral purpose, relationships, knowledge, sustainability, complexity/chaos & evolutionary theories, systems, paradoxes, coherence and theory of action. Connections to key thinkers in sociology, educational change and mentors as well as Fullan' unique approach to the change process among various other change process models, definitions and perspectives were highlighted. Development and evolution of Fullan's theory of education is underscored by the influence of early mentors in sociology as well as decades of emphasis on certain critical issues within the literature: namely, the absence of the implementation perspective (1970s), meaning-making (1980s), capacity-building (1990s), systems-leading (2000s) and a more recent post-standardization era. Critical and positive commentaries on particular Fullan's works reveal multiple and often opposing values, assumptions and purposes of education that characterize scholar's experiences and advocacy. The paper concludes with a brief personal and critical reflection on Fullan's educational change literature highlighting strengths, weaknesses and the future challenges for scholars in the field.Thesis (PhD) — Boston College, 2009.Submitted to: Boston College. Lynch School of Education.Discipline: Educational Administration

Language Learning Guide Mobile Application

While traveling around the world, a lack of common language is often encountered. This can be a reason of not truly experiencing the country and the people that one is visiting. Thus, knowing even just a little of the local language will be a great advantage for any foreigner visiting or staying in another country. This project focuses on developing a mobile application that would aid any traveller or foreigner here in Malaysia in learning to converse in the local language for a better stay. This project also attempts to find the effective, efficient and interesting ways to learn a language. It is focused in providing the user the basic conversations that a foreigner will mostly/likely encounter while visiting or staying in Malaysia. The application is for foreigners who can speak English and is trying to learn Bahasa Malaysia. The android platform is chosen for the development of the application and coding with Java and Eclipse were used. The research and survey done resulted in the findings that using visual-audio sensory and interactive techniques will provide a more engaging and thus a more effective way of learning. With this implemented in the application, results of the user acceptance test showed that with the mobile application, an increase of the competency of the users’ Bahasa Malaysia speaking skills is observed

A Blended Artificial Intelligence Approach for Spectral Classification of Stars in Massive Astronomical Surveys

[Abstract] This paper analyzes and compares the sensitivity and suitability of several artificial intelligence techniques applied to the Morgan–Keenan (MK) system for the classification of stars. The MK system is based on a sequence of spectral prototypes that allows classifying stars according to their effective temperature and luminosity through the study of their optical stellar spectra. Here, we include the method description and the results achieved by the different intelligent models developed thus far in our ongoing stellar classification project: fuzzy knowledge-based systems, backpropagation, radial basis function (RBF) and Kohonen artificial neural networks. Since one of today’s major challenges in this area of astrophysics is the exploitation of large terrestrial and space databases, we propose a final hybrid system that integrates the best intelligent techniques, automatically collects the most important spectral features, and determines the spectral type and luminosity level of the stars according to the MK standard system. This hybrid approach truly emulates the behavior of human experts in this area, resulting in higher success rates than any of the individual implemented techniques. In the final classification system, the most suitable methods are selected for each individual spectrum, which implies a remarkable contribution to the automatic classification process.This work was supported by Ministry of Science, Innovation and Universities (FEDER RTI2018-095076-B-C22) and Xunta de Galicia (ED431B 2018/42)Xunta de Galicia; ED431B 2018/4