344 research outputs found
Credit rating agencies and unsystematic risk: Is there a linkage?
This study analyzes the effects of six different credit rating announcements on systematic and unsystematic risk in Spanish companies listed on the Electronic Continuous Stock Market from 1988 to 2010. We use an extension of the event study dummy approach that includes direct effects on beta risk and on volatility. We find effects in both kinds of risk, indicating that rating agencies provide information to the market. Rating actions that imply an improvement in credit quality cause lower systematic and unsystematic risk. Conversely, ratings announcements that imply credit quality deterioration cause a rebalance in both types of risk, with higher beta risk being joined with lower diversifiable risk. Although the event characteristics were not important to determine how the two types of risk reacted to rating actions, the 2007 economic and financial crises increase the market’s sensitivity to these characteristics
Kinematic simulator of an industrial robot arm
Este trabajo fin de grado trata sobre la implementación de un simulador cinemático de un robot manipulador industrial, orientado al aprendizaje de los principios de programación y desarrollado mediante la herramienta de software matemático MATLAB, dicho simulador debe tener como características principales ser capaz de emular las características de programación que incorporan los lenguajes a nivel robot y resultar fácilmente accesible a los alumnos de las ingenierías.
Asimismo, el simulador tendrá la capacidad de definir los objetos que integran el entorno físico que rodean al robot con el objeto de simular la interacción cinemática del brazo manipulador con dicho entorno.
Para ello, primero se realizará un estudio de los lenguajes de nivel robot, en este caso concreto V+, con el objeto de elaborar un catálogo de funciones y estructuras relevantes, concretamente se trataran las estructuras de datos, funciones del robot, etc. A partir de estos, se elaborarán las especificaciones que debe cumplir el simulador cinemático.
Por último se realizarán unas prácticas sobre el simulador orientadas al aprendizaje y elaboración de los manuales de usuario del mismo
Synthesis and characterization of titanium-vanadium ternary nitride (TixV1-xN).
En el presente trabajo se aborda la síntesis del nitruro ternario de titanio y vanadio por reducción carbotérmica de una mezcla de óxidos o bien por nitruración directa de la mezcla de metales, en todo el rango de composiciones empleando el método de análisis térmico a velocidad controlada (ATVC). La caracterización de los productos obtenidos se ha llevado a cabo mediante difracción de rayos-X y microscopia electrónica. El empleo de la técnica EELS ha mostrado su capacidad para la cuantificación de este tipo de materiales, así como la utilización de la técnica espectroscópica XAS nos ha servido para corroborar los datos obtenidos a partir de los diagramas de difracción de rayos-X sobre distancias de enlace, número de coordinación y grado de desorden, esto último no detectado por las otras técnicas usadas en la caracterización de los productos. Los valores de microdureza registrados para las muestras sintetizadas se encuentran dentro del rango de valores reportados para este tipo de materiales.Titanium-Vanadium nitride (TiVN) has been prepared from carbothermal reduction of corresponding oxides and also by direct nitridation of a mix of two metals employing the ATVC method. The characterization of the final product by X-ray diffraction, scanning electron microscopy, electron energy loss (EELS), and X-ray absorption spectroscopy (XAS) is presented.The synthesis of the ternary nitride has been possible in all range of composition and the final product is obtained with nanometric particle size and a high microhardness after sintering
Innovative Methodologies in a Pandemic: The VESS Model
The VESS (Meaningful Life with Balance and Wisdom) model is considered to be a learning method based on the construction of knowledge through critical and visible thinking, with a neuroeducational base. The aim of the present work is to conduct a psychometric study of a measurement scale about the learning of the VESS model created for teachers-in-training. This article presents two survey-based descriptive studies conducted at the University of Cordoba (Spain). The data were subjected to descriptive, correlational, reliability and validity analysis through exploratory and confirmatory analyses, respectively. It is an instrument with high goodness-of-fit indices and suitable validity and reliability values. This instrument is applicable to similar study contexts
La enfermedad crónica infantil. Repercusiones emocionales en el paciente y en la familia.
La OMS define la salud como el estado de completo bienestar físico, mental y social. De este modo, se pasa de entender la salud únicamente como un concepto biológico, para entenderla como una dimensión biopsicosocial (Rubio et al., 2010). En general, la enfermedad, sobre todo cuando es crónica, altera en gran medida tanto la vida del paciente, como la de todas las personas de su entorno, y hace necesaria una adaptación a la situación de todas las partes implicadas (particularmente el niño y la familia). En el siguiente trabajo se pretenden analizar las distintas estrategias de afrontamiento emocional que, según la bibliografía relevante en este tema, tanto el paciente pediátrico como su círculo social más importante adoptan ante la nueva situación.Investigación realizada gracias al Proyecto I+D con ref.: EDU2009-11950 del Ministerio de Ciencia e Innovación.peerReviewe
Fe-Containing MOFs as Seeds for the Preparation of Highly Active Fe/Al-SBA-15 Catalysts in the N-Alkylation of Aniline
We have successfully incorporated iron species into mesoporous aluminosilicates (AlSBA15) using a simple mechanochemical milling method. The catalysts were characterized by nitrogen physisorption, inductively coupled plasma mass spectrometry (ICP-MS), pyridine (PY) and 2,6-dimethylpyridine (DMPY) pulse chromatography titration, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The catalysts were tested in the N-alkylation reaction of aniline with benzyl alcohol for imine production. According to the results, the iron sources, acidity of catalyst and reaction conditions were important factors influencing the reaction. The catalyst showed excellent catalytic performance, achieving 97% of aniline conversion and 96% of imine selectivity under optimized conditions
Design of the laboratory script by the students in chemistry practicals: Analysis of water
Comunicació presentada a INTED2018, 12th International Technology, Education and Development Conference. (March 5-7, 2018, Valencia, Spain).The laboratory practices during the Degree in Chemistry are currently designed so that the student must learn and execute a fully developed experimental protocol, previously written up by the professor, which contains all the information and requirements for the correct development of each laboratory session. Under these conditions, students do not need to take any initiative and, consequently, they do not put enough effort in reaching practical abilities with a well-based scientific criterion and do not try to think over the purpose of each lab operation, as well as the reason to use each material and/or each reagent. Thus, with the aim to promote a more active role of the students in their learning process and to improve their autonomy, a new laboratory practices design has been developed in this work, which follows methodologies on project-based cooperative learning: the students have been requested to elaborate themselves the laboratory script by pairs. With this innovative design, we pursue to involve the students in both elaboration and execution steps of the laboratory practicals, and then to increase their attention on them. Besides, the required bibliographic research would improve their knowledge about the studied topic and all aspects about the work at the laboratory. The practicals to-be-developed were related to the study of the physico-chemical quality of natural water, which has a high social relevance
Management of diversity in master classroom: an increasing challenge for science education in valencian universities
Comunicació presentada a INTED2018, 12th International Technology, Education and Development Conference. (March 5-7, 2018, Valencia, Spain).Currently, many foreign students study a Master degree at the Valencian Universities. We can find students, which have immigrated to Spain in the recent years, and then have partially or fully follow the Spanish curricula (High School and/or Grade), and others which have come specifically to study the Master, attracted by the reputation of the Universities and the job and way-of-life offered by the country, and then have achieved their Grade in their countries. This has increased the diversity of the students in the classrooms, related to the ethnic origin, mother language, study practices, background and integration in the society. The present work gives an overview on how students and teacher manage the heterogeneity and diversity in a Master classroom related to chemistry. The term “diversity” is first detailed prior to discussing explicit studies. Different aspects of diversity are stated. The personal experience of the foreign students to adapt to the Spanish courses and environment was investigated. The actions taken by the lecturer to take advantage of diversity and minimize its negative effects were examined. A comparison between the academic results obtained by international and national students is given. Finally, the attention will be focused on language, study practices and background, since these dimensions are frequently discussed in the Valencian context. The implications and opportunities that offer diversity for national but also for international science research are presented
Obatoclax and Paclitaxel Synergistically Induce Apoptosis and Overcome Paclitaxel Resistance in Urothelial Cancer Cells
Paclitaxel is a treatment option for advanced or metastatic bladder cancer after the failure of first-line cisplatin and gemcitabine, although resistance limits its clinical benefits. Mcl-1 is an anti-apoptotic protein that promotes resistance to paclitaxel in different tumors. Obatoclax, a BH3 mimetic of the Bcl-2 family of proteins, antagonizes Mcl-1 and hence may reverse paclitaxel resistance in Mcl-1-overexpressing tumors. In this study, paclitaxel-sensitive 5637 and -resistant HT1197 bladder cancer cells were treated with paclitaxel, obatoclax, or combinations of both. Apoptosis, cell cycle, and autophagy were measured by Western blot, flow cytometry, and fluorescence microscopy. Moreover, Mcl-1 expression was analyzed by immunohistochemistry in bladder carcinoma tissues. Our results confirmed that paclitaxel alone induced Mcl-1 downregulation and apoptosis in 5637, but not in HT1197 cells; however, combinations of obatoclax and paclitaxel sensitized HT1197 cells to the treatment. In obatoclax-treated 5637 and obatoclax + paclitaxel-treated HT1197 cells, the blockade of the autophagic flux correlated with apoptosis and was associated with caspase-dependent cleavage of beclin-1. Obatoclax alone delayed the cell cycle in 5637, but not in HT1197 cells, whereas combinations of both retarded the cell cycle and reduced mitotic slippage. In conclusion, obatoclax sensitizes HT1197 cells to paclitaxel-induced apoptosis through the blockade of the autophagic flux and effects on the cell cycle. Furthermore, Mcl-1 is overexpressed in many invasive bladder carcinomas, and it is related to tumor progression, so Mcl-1 expression may be of predictive value in bladder cancer.España, Sistema Público Andaluz Biobanco y ISCIII-Red de Biobancos PT17/0015/004
Psychometric study of a scale on the use of video games for the initial training of teachers
The present study is focused on analyzing the properties and psychometric characteristics of the Questionnaire about the use of video games in Higher Education. Specifically, in this work we focus on the use of a classic video game, such as Lemmings, to work on the curriculum of the Early Childhood Education stage. The instrument was created ad hoc, based on a Likert scale of 5 response options and three dimensions: student/player profile, quality of the video game and assessment of the video game as a teaching resource.
Regarding validity, two studies have been carried out, one with an exploratory nature with half of the sample, 131 participants; and another confirmatory with the total number of the participants, 261 students from the Early Childhood Education Degree at the University of Córdoba (Spain), considering the convergent and discriminant validity coefficients. Lastly, a correlational study was also carried out to clarify the relationships established between the different dimensions of the questionnaire. The results achieved demonstrate that the instrument obtained had a coherent and adequate internal structure with the theoretical assumptions initially raised, as the goodness-of-fit indexes of the confirmed model were high, at the same time showing high validity and reliability
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