Éxitos, perspectivas y aspectos críticos de la Educación a Distancia en Ciencias Económicas en la FernUniversität Hagen.

Resumen basado en el de la publicación

Aplicaciones informáticas educativas para la enseñanza a distancia : algunos aspectos de diseño y formatos de presentación.

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Conocimiento del medio natural, social y cultural. Gentes, pueblos y ciudades

Se muestra el cuarto volumen de una serie de cinco libros que tratan de forma gradual los contenidos canarios, que seg??n la normativa deben contemplarse en los curr??culos de la Educaci??n Primaria. El objetivo es facilitar al profesorado de las ??reas de Conocimiento del Medio Natural, Social y Cultural la organizaci??n y programaci??n de tales contenidos, con materiales y actividades que desarrollen en el alumnado el conocimiento y valoraci??n de las Islas. Se analizan, en este libro, los aspectos demogr??ficos y el fen??meno migratorio, adem??s de la valoraci??n del territorio como espacio de convivencia modificado por el desarrollo urbano. Se presta especial atenci??n a las partes esenciales de los n??cleos de poblaci??n en las que se integran las zonas antiguas, estimulando al alumnado a su valoraci??n y conservaci??n.

La ense??anza de idiomas en Alemania

Se analiza el ??xito de la ense??anza de idiomas en el sistema educativo alem??n, que a pesar de ser tan complejo, con diecis??is estados federados, su alumnado puede presumir de una de las formaciones en lenguas extranjeras m??s s??lidas de Europa. Se hace una comparativa con el sistema espa??ol, concluyendo entre otros aspectos, que una de las cosas que explican este ??xito es la importancia de la educaci??n en infantil como pilar de las etapas posteriores, ense??anza no obligatoria que se desarrolla habitualmente en otros idiomas. Por otro lado, en la educaci??n primaria se priorizan las destrezas orales y comunicativas, mientras que en Espa??a se concede la misma importancia a las cuatro destrezas en sus aspectos oral y escrito. En cuanto a la educaci??n secundaria el alumnado es derivado seg??n sus capacidades a distintos tipos de centros, en los que se pueden estudiar hasta tres lenguas extranjeras. Cabe destacar tambi??n la importancia que se da a los idiomas en las ense??anzas no regladas as?? como la tolerancia que muestra la ciudadan??a de este pa??s hacia otras lenguas y culturas.

Los aspectos culturales en la ense??anza del espa??ol lengua de especialidad: plan curricular para alumnos germanoparlantes del sector tur??stico

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Formación permanente del profesorado de educación primaria en planificación y didáctica del conocimiento del medio natural, en base a las nuevas tendencias educativas: un modelo formativo y aplicaciones concretas

La propuesta de modelo de formación del profesorado que seguidamente va a ser descrita1, basada en los nuevos planteamientos educativos referidos y diseñada en atención específica a la realidad de la Comunidad Autónoma andaluza -si bien generalizable en muchos aspectos a otras- y para la etapa concreta de Educación Primaria, ofrece pautas de actuación para el ámbito de conocimiento concreto de las ciencias experimentales, o lo que es lo mismo, para el relativo al del conocimiento del medio natural

El discurso de la identidad Vascófona : usos politicos, sociales y biograficos

La pluralidad “irreductible” de los vascos ha entrado hace poco en los discursos políticos. Es esperable que a medida que los aspectos más violentos del conflicto en el que ha vivido el país vayan desapareciendo, esta pluralidad sea cada vez más admitida y menos disonante. Trataremos en este trabajo de dar una idea acerca de un discurso particular de la identidad vascófona.

Proyección de imagen a través de la prensa internacional. Caso: Guerra del gas en Bolivia

El propósito de la presente Tesis de Maestría consiste en permitir, en primera instancia, comprender la naturaleza y la propia problemática de la renuncia del Presidente Sánchez de Lozada y de lo que conllevó la “Guerra del Gas Boliviana”, principalmente desde la acción a nivel internacional que tuvieron los periódicos: El Comercio (Ecuador), La Nación (Argentina), El Universal (México), y El Mundo (España); en relación a la información que difundieron sobre dicha conflictividad. En este marco, se siguió una estrategia teórica que buscó indagar las situaciones fundamentales relacionadas con la historia, economía, política y cultura del conflicto; además de la directa implicación a nivel internacional que ello conllevó gracias al tratamiento y emisión de contenidos realizados por los medios analizados. Las páginas que siguen, por lo tanto, permitirán mostrar cómo se estructuraron y sistematizaron los aspectos centrales implicados en la denominada “Guerra del Gas”, principalmente desde la perspectiva de la prensa internacional y su repercusión en el ámbito exterior. Aspectos formalizados a partir de la recopilación de una amplia bibliografía y documentación, con la intención de brindar una propuesta interesante de ser tomada en cuenta a la vez de original en relación a la problemática planteada. A partir de esto se podrán apreciar contenidos imprescindibles desarrollados en los dos primeros capítulos, el primero de los cuales permite comprender la forma en que los medios trataron y difundieron los contenidos, mientras que el segundó brinda la posibilidad de entender a la problemática boliviana como un factor estructural e históricamente complejo. Contenidos que interactúan y desarrollan a lo largo del último capítulo.

Verification of design calculations of a wind catcher/tower natural ventilation system with performance testing in real building

A wind catcher/tower natural ventilation system was installed in a seminar room in the building of the School of Construction Management and Engineering, the University of Reading in the UK . Performance was analysed by means of ventilation tracer gas measurements, indoor climate measurements (temperature, humidity, CO2) and occupant surveys. In addition, the potential of simple design tools was evaluated by comparing observed ventilation results with those predicted by an explicit ventilation model and the AIDA implicit ventilation model. To support this analysis, external climate parameters (wind speed and direction, solar radiation, external temperature and humidity) were also monitored. The results showed the chosen ventilation design provided a substantially greater ventilation rate than an equivalent area of openable window. Also air quality parameters stayed within accepted norms while occupants expressed general satisfaction with the system and with comfort conditions. Night cooling was maximised by using the system in combination with openable windows. Comparisons of calculations with ventilation rate measurements showed that while AIDA gave reasonably correlated results with the monitored performance results, the widely used industry explicit model was found to over estimate the monitored ventilation rate.

Analysis of 'APN' naphthenic acids by high temperature gas chromatoagraphy and high performance liquid chromatography

Examination by high temperature GC (HTGC) of the methyl esters of the so-called 'ARN' naphthenic acids from crude oils of North Sea UK, Norwegian Sea and West African oilfields revealed the distributions of resolved 4-8 ring C-80 tetra acids and trace amounts of other acids. Whilst all three oils contained apparently the same the proportions of each differed, possibly reflecting the growth tempe acids, ratures of the archaebacteria from which the acids are assumed to have originated. The structures of the 4, 5, 7 and 8 ring acids are tentatively assigned by comparison with the known 6 ring acid and related natural products and an HPLC method for the isolation of the individual acids is described. ESI-MS of individual acids isolated by preparative HPLC established the elution order of the 4-8 ring acids on the HPLC and HTGC systems and revealed the presence of previously unreported acids tentatively identified as C-81 and C-82 7 and 8 ring analogues.

The use of colloidal gas aphrons as novel downstream processing for the recovery of astaxanthin from cells of Phaffia rhodozyma

BACKGROUND: There is an increasing interest in obtaining natural products with bioactive properties, using fermentation technology. However, the downstream processing consisting of multiple steps can be complicated, leading to increase in the final cost of the product. Therefore there is a need for integrated, cost-effective and scalable separation processes. RESULTS: The present study investigates the use of colloidal gas aphrons (CGA), which are surfactant-stabilized microbubbles, as a novel method for downstream processing. More particularly, their application for the recovery of astaxanthin from the cells of Phaffia rhodozyma is explored. Research carried out with standard solutions of astaxanthin and CGA generated from the cationic surfactant hexadecyl. trimethyl ammonium bromide (CTAB) showed that up to 90% recovery can be achieved under optimum conditions, i.e., pH 11 with NaOH 0.2 mol L-1. In the case of the cells' suspension from the fermentation broth, three different approaches were investigated: (a) the conventional integrated approach where CGA were applied directly; (b) CGA were applied to the clarified suspension of cells; and finally (c) the in situ approach, where CGA are generated within the clarified suspension of cells. Interestingly, in the case of the whole suspension (approach a) highest recoveries (78%) were achieved under the same conditions found to be optimal for the standard solutions. In addition, up to 97% recovery of total carotenoids could be achieved from the clarified suspension after pretreatment with NaOH. This pretreatment led to maximum cell disruption as well as optimum conditioning for subsequent CGA separation. CONCLUSIONS: These results demonstrate the potential of CGA for the recovery of bioactive components from complex feedstock. (c) 2008 Society of Chemical Industry.

Foraging strategies of natural enemies of the peach-potato aphid Myzus persicae

The foraging strategies of two natural enemies of the peach-potato aphid Myzus persicae: the seven-spot ladybird Coccinella septempunctata and the parasitoid wasp Diaeretiella rapae, were investigated. Specifically the roles of plant semiochemicals in the location of plants infested with M. persicae by these natural enemies were examined. I investigated the olfactory responses of female C. septempunctata to volatiles collected from M. persicae and four Brassica cultivars; Brassica rapa, B. juncea, B. napus cultivar ‘Apex’ and B. napus cultivar ‘Courage’ and wild-type Arabidopsis thaliana that were: undamaged, previously infested by M. persicae and infested with M. persicae. C. septempunctata showed no attraction to volatiles from M. persicae alone. C. septempunctata significantly changed its searching behaviour in response to plant volatiles from B. rapa, B. napus cv. ‘Apex’ and Arabidopsis infested with M. persicae. C. septempunctata was also found to display a significant turning bias when foraging on a branching horizontal wire stem. A model was developed to investigate how turning biases affect the foraging efficiency of C. septempunctata in dichotomous branched environments. Simulations using this model indicated that turning biases could potentially increase searching efficiency. D. rapae showed a significant preference for volatiles from M. persicae infested wild-type Arabidopsis but no preference to volatiles from M. persicae alone or M. persicae honeydew. Volatile emissions by Arabidopsis were shown to be localised to the area of aphid-infestation rather than systemic. Using gas chromatography plants infested with M. persicae were shown to emit a quantitatively different volatile blend than undamaged plants. In experiments with jasmonate mutants of Arabidopsis the jasmonate (octadecanoid) wound response pathway was implicated as being important for the production of M. persicae induced volatiles, attractive to D. rapae. Other wound response pathways were also found to be involved in the production of the full blend of M. persicae induced volatiles.

A green flow-based procedure for fluorimetric determination of acid-dissociable cyanide in natural waters exploiting multicommutation

A flow system designed with solenoid valves is proposed for determination of weak acid dissociable cyanide, based on the reaction with o-phthalaldehyde (OPA) and glycine yielding a highly fluorescent isoindole derivative. The proposed procedure minimizes the main drawbacks related to the reference batch procedure, based on reaction with barbituric acid and pyridine followed by spectrophotometric detection, i.e., use of toxic reagents, high reagent consumption and waste generation, low sampling rate, and poor sensitivity. Retention of the sample zone was exploited to increase the conversion rate of the analyte with minimized sample dispersion. Linear response (r=0.999) was observed for cyanide concentrations in the range 1-200 mu g L(-1), with a detection limit (99.7% confidence level) of 0.5 mu g L(-1)(19 nmol L(-1)). The sampling rate and coefficient of variation (n=10) were estimated as 22 measurements per hour and 1.4%, respectively. The results of determination of weak acid dissociable cyanide in natural water samples were in agreement with those achieved by the batch reference procedure at the 95% confidence level. Additionally to the improvement in the analytical features in comparison with those of the flow system with continuous reagent addition (sensitivity and sampling rate 90 and 83% higher, respectively), the consumption of OPA was 230-fold lower.

La(2-x)Ce(x)Cu(1-y)Zn(y)O(4) perovskites for high temperature water-gas shift reaction

The performance of La(2-x)Ce(x)Cu(1-y)Zn(y)O(4) perovskites as catalysts for the high temperature water-gas shift reaction (H T-W G S R) was investigated. The catalysts were characterized by EDS, XRD, BET surface area, TPR, and XANES. The results showed that all the perovskites exhibited the La(2)CuO(4) orthorhombic structure, so the Pechini method is suitable for the preparation of pure perovskite. However, the La(1.90)Ce(0.10)CuO(4) perovskite alone, when calcined at 350/700 degrees C, also showed a (La(0.935)Ce(0.065))(2)CuO(4) perovskite with tetragonal structure, which produced a surface area higher than the other perovskites. The perovskites that exhibited the best catalytic performance were those calcined at 350/700 degrees C and, among these, La(1.90)Ce(0.10)CuO(4) was outstanding, probably because of the high surface area associated with the presence of the (La(0.935)Ce(0.065))(2)CuO(4) perovskite with tetragonal structure and orthorhombic La(2)CuO(4) phase.