The grape phylloxera plague as a natural experiment: the upkeep of vineyards in Catalonia (Spain), 1858-1935

We present a comparative analysis of the impact and outcome in Catalonia of the wine rush and crash unleashed by the spread of the Grape Phylloxera plague in Europe (1865-1890). In order to explain why many rural districts in the provinces of Barcelona and Tarragona were able to resume winegrowing after the plague, while most in the provinces of Girona and Lleida were not, a statistical model is used to check the economic resilience of the Catalan districts to the external ecological and economic shock. The model combines the population densities as a proxy of the opportunity cost in labour allocation, the demand pull of commercial growth measured by the time-distances to the city of Barcelona, and the agroclimatic land's suitability for growing vines, as measured by the Hugling and Winkler indices or the mean slopes of land. After comparing the vineyard allocation in every district in 1860, 1889 and 1920, these variables are used to explain the differing capacities to endure the Phylloxera plague in Catalonia

Explaining vineyard specialization in the province of Barcelona (Spain) in the mid-19th century

[cat] Presentem un model estadístic de l’especialització vitícola a la província de Barcelona cap el 1860 que combina la pressió boserupiana de l’augment de població, l’atracció de la demanda induïda per un creixement de tipus smithià (mesurada per les distancies horàries al port més proper), i l’adequació dels sòls disponibles per sembrar gra o plantar ceps (mesurada per l’estès hídric, el pendent i el risc de glaçades). L’assoliment global d’uns nivells de R2 ajustats que oscil·len entre 0,608 i 0,826 poden considerar-se força bons. Creiem que la desigualtat en la propietat de la terra també va jugar un paper molt important, però l’hem hagut d’ometre de moment per manca de dades estadístiques. També cal aprofundir en el tractament del problema de possible endogeneïtat derivat de l’ús de variables socio-demogràfiques.[eng] We present a statistical model of agrarian vineyard specialization in the province of Barcelona towards 1860, that combines the Boserupian push of population increase, the demand pull of a Smithian-type of growth (measured by the time-distances to the nearest seaport), and the agrological land’s suitability for sowing grain or growing vines (as measured by water stress, slopes and frost risk). The overall outcome of the adjusted R2 levels, which range from 0.608 to 0.826, can be considered very successful. The inequality in land ownership is another factor that we believe to have played an important role, but has had to be omitted for the moment due to the lack of statistical data. Further research is also needed to deal with a possible endogeneity problem that working with socio-demographic variables entails

La evaluación entre iguales en la educación social: entre lo profesional y lo académico

Aquest article descriu l’experiència de la metodologia d’aprenentatge basada en l’avaluació entre iguals aplicada a la professionalització dels educadors/es socials. Tant a nivell escolar com universitari, hi ha nombroses experiències publicades en relació amb la metodologia d’avaluació entre iguals. A més, existeixen nombrosos apartats dels “Documents professionalitzadors” on es justifica el fet que s’entrenin algunes habilitats que s’haurien de donar en la pràctica professional (com per exemple en la definició, en el codi ètic i en el catàleg de funcions i competències de l’educador/a social). En aquestes pàgines pretenem donar a conèixer l’experiència d’entrenament de futurs educadors/es en aspectes que tenen una relació directa amb l’avaluació entre educadors/es socials.The following article describes the experience of a learning methodology based on peer evaluation applied to the professionalization of social educators. At both school and university level, there is a wealth of published material on the methodology of the peer evaluation process. In addition, many sections of the ‘Professionalizing Documents’ justify the validity of imparting a range of skills that should be applied in professional practice (notably in its, definition in the code of ethics and in the catalogue of functions and competencies of the social educator). The aim of this article is to present the experience of training future social educators in areas that have a direct bearing on peer assessment among social educatorsEl siguiente artículo describe la experiencia de la metodología de aprendizaje basada en la evaluación entre iguales aplicada a la profesionalización de los educadores/as sociales. Tanto a nivel escolar como universitario, hay numerosas experiencias publicadas en relación con la metodología de evaluación entre iguales. Además, existen numerosos apartados de los “Documentos profesionalizadores” donde se justifica el hecho de que se entrenen algunas habilidades que deberían darse en la práctica profesional (como por ejemplo en la definición, en el código ético y en el catálogo de funciones y competencias del educador/a social). En estas páginas pretendemos dar a conocer la experiencia de entrenamiento de futuros educadores/as en aspectos que tienen una relación directa con la evaluación entre educadores/as sociale

Els Qüestionaris com a recurs docent en l'aprenentatge autònom. Resultats d'una prova pilot en un curs de Química bàsica.

En aquest article es presenten uns nous qüestionaris on line dissenyats per millorar la comprensió dels continguts de l"assignatura Química Bàsica II i, alhora, propiciar el treball autònom dels estudiants. En el grup pilot que ha disposat dels qüestionaris, els resultats acadèmics dels estudiants que els han realitzat diverses vegades han estat millors que els dels alumnes que no els han utilitzat amb regularitat. Els resultats acadèmics del grup pilot també ha estat millor que els de cursos anteriors

Intracellular characterization of Gag-GFP VLP production upon PEImediated transient transfection of HEK 293 cells

Transient Gene Expression is a fast, flexible, and cost-effective approach to produce high-quality products that circumvents the time and cost required for the generation of stably transfected cell lines. However, the levels of recombinant protein produced by TGE, tend to be significantly lower than those of stable cell lines. Despite the continued interest in transient gene expression approaches, little is known about the transfection process at intracellular level, particularly for complex products such as VLPs. The kinetics of PEI-mediated transient transfection was studied with the aim of characterizing and understanding the complete process leading to VLP generation, and identifying important events to drive process improvement. For this purpose, DNA/PEI polyplexes were tracked using Cy3 DNA staining and the production of Gag-GFP VLPs was monitored by flow cytometry, confocal microscopy, and fluorometry. Flow cytometry and confocal microscopy assays show that using a standard transfection protocol DNA:PEI polyplexes interact with the cell membrane from time point zero. A linear increase in transfection efficiency is observed until 60 minutes of contact between cells and polyplexes. No change in transfection efficiency (percentage of GFP positive cells) or VLP production levels is obtained when additional contact time is allowed, reaching a maximum transfection efficiency of 60% and VLP production of 10x109 VLPs/mL harvested at 48 hours post transfection (hpt). After 1.5 hpt, polyplexes are detected in the cytoplasm of transfected cells and reach the nucleus around 4 hpt. Of note, all cells show the presence of DNA/PEI complex in the cytoplasm after transfection but only a fraction of cells express the fluorescent Gag protein. By flow cytometry analysis of isolated nuclei, it was determined that polyplexes are only present in 60% of the nuclei at 6 hpt (concomitant with the GFP expressing cells), suggesting that the entrance of polyplexes to the nucleus is one of the limiting steps of the transfection process. After 10 hpt, GFP fluorescence is detected homogenously inside the cells, but generalized budding of VLPs is not observed until 48 hpt. As mentioned before, a unique population of cells Cy3+ (with a polyplex inside) appears from the very beginning of the transfection. A new population of cells that do not contain any polyplex inside (Cy3-) and do not express the protein (GFP-) appears at 24 hpt suggesting plasmid loss after this time point. The VLP production kinetics was also studied, observing that fluorescence in the supernatant is always 40% less than total fluorencense (supernatant plus pellet). Maximum VLP levels in the cell culture supernatant, while keeping cell culture viability still high, are observed at 72 hpt, which was determined to be the optimal harvest time. Three bottlenecks in VLP production could be identified in this work: polyplexes entry into the nucleus, plasmid loss during the production phase and VLP buddin

Optimization of HEK 293 cell growth by addition of non-animal derived components using design of experiments

European Society for Animal Cell Technology (ESACT) Meeting on Cell Based Technologies (Vienna, Austria: 22nd, 15-18 May 2011

L’educació literària: una proposta de treball per projectes

L’objectiu d’aquest treball és mostrar la importància de la metodologia del treball per projectes en l’ensenyament de la literatura en l’àmbit universitari. Partim de l’educació literària com a marc didàctic de referència amb l’objectiu que l’alumnat puga adquirir una competència literària rica i plena. Tractarem de demostrar que aquesta metodologia possibilita situar el lector com a protagonista principal del fet literari en plantejar experiències de treball més motivadores i que integren, de manera globalitzada, les diverses competències específiques de la formació literària dels futurs mestres. A més, aquesta metodologia facilita el desenvolupament dels conceptes, procediments i actituds o valors necessaris per aconseguir un aprenentatge significatiu de la literatura, tot evitant així alguns dels problemes plantejats en models d’ensenyament més tradicionals i positivistes.The aim of this paper is to show the importance of the methodology of project work in teaching literature at the university level. The literary education is our starting point as a the teaching reference framework in order to make our students acquire an utter literary competence. We will try to prove that this methodology lets the reader be the main character of the literary experience as the programmed activities are more motivating and integrate from a holistic approach the specific competences of future teachers as far as their literary training is concerned. In addition, this methodology enables the development of concepts, procedures and attitudes or values that are necessary to learn literature meaningfully, by doing so, students are prevented from some of the problems in traditional teaching models

Design of 3D environment to develop preservice teachers' digital competence: usability, adequacy and perceived usefulness

Una de las condiciones esenciales para el desarrollo de la competencia digital docente de los futuros docentes es proporcionarles situaciones de aprendizaje que permitan ejercitar tales habilidades, conocimientos y actitudes en contextos similares a su futura realidad profesional. Los entornos virtuales 3D, altamente inmersivos e interactivos, son una tecnología prometedora para simular escenarios reales y ofrecer dichas oportunidades de aprendizaje. El objetivo de esta investigación es presentar el diseño de un entorno 3D para el desarrollo de la competencia digital docente, centrado en el análisis de: (1) la usabilidad tecnológica y gráfica; (2) la adecuación del contenido de las actividades; y (3) la practicidad y utilidad pedagógica del entorno. Para ello, siguiendo la metodología de investigación para el diseño, se llevó a cabo un proceso de validación con distintos grupos de informantes clave: expertos en tecnología, docentes relacionados con la tecnología educativa y estudiantes de los grados de educación, a los que, además, se les administró un cuestionario de percepción de la utilidad pedagógica (Code et al. 2013). Los resultados muestran que a nivel tecnológico el entorno funcionó de manera fluida, aunque los gráficos resultaron limitados. A nivel didáctico, las actividades propuestas fueron adecuadas, realistas y actuales, y, a pesar de la complejidad inicial en el control de los avatares, destaca la alta motivación de los estudiantes debido a la similitud del entorno con su futura práctica profesional. La principal conclusión es que los entornos 3D son escenarios viables para el desarrollo actividades didácticas que favorezcan la adquisición de la competencia digital docente.One of the most important conditions for the development of preservice teachers' digital competence is to provide them with learning experiences to put in action such skills, knowledge and attitudes in similar contexts to their future professional reality. 3D virtual environments are an immersive and interactive promising technology that allow to simulate real scenarios and provide these learning opportunities. The aim of this reserach is to show the design of a 3D environment for the development of teachers' digital competence, focusing to the analysis of: (1) technical and graphical usability; (2) content adequacy of the activities; and (3) practicity and pedagogical usability of the environment. For this purpose, following designbased research method, we conducted a validity process with different key informants groups: technology experts, teachers related to educational technology, and studentsteachers who also answered a pedagogical usability questionnaire (Code et al., 2013). From a technological view, the results show that the environment worked fluently, but the graphics were limited. From a educational point of view, the activities were appropriate, realistic and current. the activities were appropriate, realistic and current. Despite the initial complexity in the avatars control, they emphasized its high motivation due to the similarity of 3D environment with their future professional work. The main conclusion of this work was that 3D environments are useful technology for developing educational activities that promote the acquisition of teachers' digital competence