Evolución y desarrollo de un Entorno Personal de Aprendizaje en la Universidad de León

The present paper has been developed in different classrooms since 2006 in order to train students for Mathematics and Teaching at the Faculty of Education (University of León). The students are committed to a participatory and collaborative work, and they have been guided by ongoing assessment based training for more than four years. In this time they have been implementing various web-based Tools in order to reach what is today called a personal learning environment (PLE). The protagonists of the learning / teaching process are the students themselves. As teachers in training, they must demonstrate a range of skills and professional development skills in their jobs and also the skills of information retrieval and critical thinking through this custom platform. They have conducted surveys and interviews in order to measure the necessary skills to manage this connective environment network. In this article, there is a preliminary study of external influences needed to develop this environment. In a second phase we can see the evolution of performance under this personal learning environment and its objectives: the ability to self-manage their own learning of Mathematics teaching and the problems that they have arisen at the University because of being an isolated experience and a lack of commitment to self-organized and negotiated learning

Propuesta metodológica para la implementación de la gestión del conocimiento en una empresa de consultoría

El proceso de crecimiento de las organizaciones en gran medida, depende del desarrollo de un concepto que ha adquirido relevancia en los últimos 10 años denominado Gestión del Conocimiento, el cual se encuentra fundamentado en el valor del conocimiento, entendido como la información que se posee dentro de un contexto. Cada empleado que pertenece a una empresa posee un determinado conocimiento, de manera que gracias a un proceso bien elaborado y continuo debe ampliarlo, compartirlo y actualizarlo, logrando optimizar cada día la labor que realiza. Por otro lado, la suma del conocimiento que poseen los miembros de la compañía se denomina Capital Intelectual y va enfocado directamente en el fortalecimiento de la competitividad como eje central del aprendizaje organizacional

Reversibility of the zinc-blende to rock-salt phase transition in cadmium sulfide nanocrystals

CdS nanoparticles prepared by a mechanochemical reaction in a planetary ball mill have been investigated by x-ray diffraction, optical absorption, and Raman scattering under high pressure conditions up to 11 GPa. The zinc-blende (ZB) to rock-salt phase transition is observed around 6 GPa in all experiments, the transition pressure being similar to the one measured in CdS colloidal nanocrystals, and much higher than in bulk (around 3 GPa). The direct optical energy gap in ZB-CdS increases with pressure, and suddenly drops when the pressure is raised above 6 GPa, according to the high-pressure indirect-gap behavior. A linear blue-shift of the CdS Raman spectra is observed upon increasing pressure. Both Raman and x-ray diffraction studies indicate that the phase transition has a large hysteresis, making the ZB phase barely recoverable at ambient conditions. Cell parameters and bulk modulus measured in CdS nanoparticles clearly show that the nanoparticles at ambient conditions are subject to an initial pressure in comparison to CdS bulk.This work was financially supported by the Spanish Ministerio de Ciencia e Innovación (Projects MAT2008-06873-C02-01/MAT, MAT2011-28868-C02-01 and CTQ2009-14596-C02-01), the Comunidad de Madrid and European Social Fund (Project S2009/PPQ-1551 4161893 (QUIMAPRES)), and the MALTA-Consolider Ingenio 2010 (Reference CSD2007-00045). R.M.-R. thanks the Spanish MEC for a FPI research grant (Reference BES-2006-13359). The expert assistance of L. Rodríguez at the SERTEM is gratefully acknowledged

Multivariate wave climate using self-organizing maps

ABSTRACT: The visual description of wave climate is usually limited to two-dimensional conditional histograms. In this work, self-organizing maps (SOMs), because of their visualization properties, are used to characterize multivariate wave climate. The SOMs are applied to time series of sea-state parameters at a particular location provided by ocean reanalysis databases. Trivariate (significant wave height, mean period, and mean direction), pentavariate (the previous wave parameters and wind velocity and direction), and hexavariate (three wave parameters of the sea and swell components; or the wave, wind, and storm surge) classifications are explored. This clustering technique is also applied to wave and wind data at several locations to analyze their spatial relationship. Several processes are established in order to improve the results, the most relevant being a preselection of data by means a maximum dissimilarity algorithm (MDA). Results show that the SOM identifies the relevant multivariate sea-state types at a particular location spanning the historical variability, and provides an outstanding analysis of the dependency between the different parameters by visual inspection. In the case of wave climate characterizations for several locations the SOM is able to extract the qualitative spatial sea-state patterns, allowing the analysis of the spatial variability and the relationship between different locations. Moreover, the distribution of sea states over the reanalysis period defines a probability density function on the lattice, providing a visual interpretation of the seasonality and interannuality of the multivariate wave climate.The work was partially funded by projects GRACCIE (CSD2007-00067, CONSOLIDERINGENIO 2010) from the Spanish Ministry of Science and Technology, MARUCA(200800050084091) from the Spanish Ministry of Public Works, and C3E(E17/08) from the Spanish Ministry of Environment, Rural and Marine Environs. The authors thank Puertos del Estado (Spanish Ministry of Public Works) for providing the reanalysis database

Elevated expression levels of lysyl oxidases protect against aortic aneurysm progression in Marfan syndrome

© 2015 Elsevier Ltd. Patients with Marfan syndrome (MFS) are at high risk of life-threatening aortic dissections. The condition is caused by mutations in the gene encoding fibrillin-1, an essential component in the formation of elastic fibers. While experimental findings in animal models of the disease have shown the involvement of transforming growth factor-β (TGF-β)- and angiotensin II-dependent pathways, alterations in the vascular extracellular matrix (ECM) may also play a role in the onset and progression of the aortic disease. Lysyl oxidases (LOX) are extracellular enzymes, which initiates the formation of covalent cross-linking of collagens and elastin, thereby contributing to the maturation of the ECM. Here we have explored the role of LOX in the formation of aortic aneurysms in MFS. We show that aortic tissue from MFS patients and MFS mouse model (Fbn1C1039G/+) displayed enhanced expression of the members of the LOX family, LOX and LOX-like 1 (LOXL1), and this is associated with the formation of mature collagen fibers. Administration of a LOX inhibitor for 8weeks blocked collagen accumulation and aggravated elastic fiber impairment, and these effects correlated with the induction of a strong and rapidly progressing aortic dilatation, and with premature death in the more severe MFS mouse model, Fbn1mgR/mgR, without any significant effect on wild type animals. This detrimental effect occurred preferentially in the ascending portion of the aorta, with little or no involvement of the aortic root, and was associated to an overactivation of both canonical and non-canonical TGF-β signaling pathways. The blockade of angiotensin II type I receptor with losartan restored TGF-β signaling activation, normalized elastic fiber impairment and prevented the aortic dilatation induced by LOX inhibition in Fbn1C1039G/+ mice. Our data indicate that LOX enzymes and LOX-mediated collagen accumulation play a critical protective role in aneurysm formation in MFS.Ministerio de Economía y Competitividad (Plan Nacional de I + D + I: SAF2012-34916), and Comunidad Autónoma deMadrid: 2010-BMD2321, FIBROTEAMConsortium, to F.R-P.; Howard Hughes Medical Institute, Smilow Center for Marfan Syndrome Research, The Marfan Foundation, and the National Institutes of Health (AR41135 and AR049698) to H.C.D.; and Ministerio de Economía y Competitividad (Plan Nacional de I + D + I: BFU2012- 33932), Fundación Ramón Areces and the National Marfan FoundationPeer Reviewe

LoXL4 is induced by transforming growth factor β1 through Smad and JunB/Fra2 and contributes to vascular matrix remodeling

Transforming growth factor β1 (TGF-β1) is a pleiotropic factor involved in the regulation of extracellular matrix (ECM) synthesis and remodeling. In search for novel genes mediating the action of TGF-β1 on vascular ECM, we identified the member of the lysyl oxidase family of matrix-remodeling enzymes, lysyl oxidase-like 4 (LOXL4), as a direct target of TGF-β1 in aortic endothelial cells, and we dissected the molecular mechanism of its induction. Deletion mapping and mutagenesis analysis of the LOXL4 promoter demonstrated the absolute requirement of a distal enhancer containing an activator protein 1 (AP-1) site and a Smad binding element for TGF-β1 to induce LOXL4 expression. Functional cooperation between Smad proteins and the AP-1 complex composed of JunB/Fra2 accounted for the action of TGF-β1, which involved the extracellular signal-regulated kinase (ERK)- dependent phosphorylation of Fra2. We furthermore provide evidence that LOXL4 was extracellularly secreted and significantly contributed to ECM deposition and assembly. These results suggest that TGF-β1-dependent expression of LOXL4 plays a role in vascular ECM homeostasis, contributing to vascular processes associated with ECM remodeling and fibrosis.This work was supported by grants from the Ministerio de Economía y Competitividad (Plan Nacional de I+D+I: SAF2009-09085, SAF2012-34916), Comunidad Autónoma de Madrid (2010-BMD2321, FIBROTEAM Consortium), Fundación Genoma España (MEICA project), Consejo Superior de Investigaciones Científicas (Proyecto Intramural de Incorporación, 200920I158), and Fundación Renal Iñigo Alvárez de Toledo. O.B. is a recipient of a fellowship from the Ministerio de Economía y Competi- tividad (Formación de Personal Investigador)Peer Reviewe

Una mirada retrospectiva a la evolución del docente de Matemáticas desde la perspectiva narratológica.

Este trabajo describe un ejercicio de investigación que profundiza sobre las reflexiones de los docentes en torno a sus relatos de vida. Las herramientas narrativas empleadas para la recolección de la información fueron: la autobiografía profesional temática e intelectual, las cuales permiten producir reflexiones, propiciar la constitución de subjetividades y procesos de transformación como docentes de matemáticas. Los resultados proponen los elementos comunes encontrados en los relatos a través de cláusulas, hechos y acontecimientos, los cuales abrirán nuevas posibilidades para poder repensar ambientes de aprendizajes distintos para los maestros en formación, contribuyendo con la resignificación de la narrativa como medio para examinar la experiencia profesional.Magister en Docencia de la MatemáticaMaestrí

Hot but Not Dry: Modest Changes in Water Relations for an Epiphytic Bromeliad in a Tropical Dry Deciduous Forest

Premise of research. Epiphytic bromeliads endure intense seasonal environmental changes in the canopy of dry tropical deciduous forests. The analysis of the physiological responses of these epiphytes to environmental changes can be useful in assessing their plasticity, vulnerability, and adaptations to such extreme habitats. Methodology. We measured microenvironmental variables and water relations for plants of the epiphytic bromeliad Tillandsia brachycaulos in three microhabitats within the canopy of a dry tropical forest. We measured individual plants for seasonal and spatial differences in light, leaf temperature, osmotic potential, cell wall elasticity, and relative capacitance as indications of their physiological responses to the changing environment. Pivotal results. We detected greater physiological differences for leaves of T. brachycaulos among seasons than among microhabitats. Osmotic potential decreased in the early dry season, especially in the low and middle strata within the canopy, and leaf relative capacitance increased. Conclusions. Individuals of T. brachycaulos displayed modest leaf physiological responses to the strong seasonal environmental changes within the canopy of this tropical forest. Such responses are in agreement with the observation that when water is available, it has high water potential, and thus water storage is the main strategy for surviving in such extreme conditions

Pressure-induced phase transition and band gap decrease in semiconducting β-Cu2V2O7

The understanding of the interplay between crystal structure and electronic structure in semiconductor materials is of great importance due to their potential technological applications. Pressure is an ideal external control parameter to tune the crystal structures of semiconductor materials in order to investigate their emergent piezo-electrical and optical properties. Accordingly, we investigate here the high-pressure behavior of the semiconducting antiferromagnetic material β-Cu2V2O7, finding it undergoes a pressure-induced phase transition to γ-Cu2V2O7 below 4000 atm. The pressure-induced structural and electronic evolutions are investigated by single-crystal X-ray diffraction, absorption spectroscopy and ab initio density functional theory calculations. β-Cu2V2O7 has previously been suggested as a promising photocatalyst for water splitting. Now, these new results suggest that β-Cu2V2O7 could also be of interest with regards to barocaloric effects, due to the low phase -transition pressure, in particular because it is a multiferroic material. Moreover, the phase transition involves an electronic band gap decrease of approximately 0.2 eV (from 1.93 to 1.75 eV) and a large structural volume collapse of approximately 7%.The authors acknowledge financial support from the Spanish Research Agency (AEI) and Spanish Ministry of Science and Investigation (MCIN) under projects PID2019106383GBC41/ C43/C44 (DOI: 10.13039/501100011033), and projects PGC2018-101464−B-I00 and PGC2018-097520-A-I00 (cofinanced by EU FEDER funds). The authors acknowledge financial support from the MALTA Consolider Team network, under project RED2018-102612-T. R.T. acknowledges funding from the Spanish Ministry of economy and competitiveness (MINECO) via the Juan de la Cierva Formación program (FJC2018-036185-I). J.G.P. thanks the Servicios Generales de Apoyo a la Investigación (SEGAI) at the University of La Laguna. A.L. and D.E. would like to thank the Generalitat Valenciana for the Ph.D. fellowship GRISOLIAP/2019/025, and the authors would also like to thank them for funding under the Grant Prometeo/2018/123 (EFIMAT). The authors also thank ALBA synchrotron light source for funded experiment under proposal numbers 2020074389 and 2020074398 at the MSPD-BL04 beamline