333 research outputs found
Contribution of dust inputs to dissolved organic carbon and water transparency in Mediterranean reservoirs
The Mediterranean reservoirs receive frequent atmospheric Saharan dust inputs with soil-derived organic components mostly during the stratification periods, when run-off inputs are particularly limited. Here, we quantified and optically characterized the water-soluble organic carbon (WSOC) of the (dry and wet) atmospheric deposition in collectors placed near three reservoirs from the western Mediterranean Basin. In addition, we determined the WSOC contribution to the pool of dissolved organic carbon (DOC) in the reservoirs and the influence of dust-derived chromophoric organic components on the water transparency during their stratification periods.
We found synchronous dynamics in the WSOC atmospheric inputs among the three collectors and in the DOC concentrations among the three reservoirs. The DOC concentrations and the WSOC atmospheric inputs were positive and significantly correlated in the most oligotrophic reservoir (Quéntar) and in the reservoir with the highest ratio of surface area to mixing water depth (Cubillas). Despite these correlations, WSOC atmospheric inputs represented less than 10% of the total DOC pool, suggesting that indirect effects of dust inputs on reservoir DOC may also promote these synchronous patterns observed in the reservoirs. Chromophoric components from dust inputs can significantly reduce the water transparency to the ultraviolet radiation (UVR). The depths where UVR at λ = 320 nm was reduced to ten percent of surface intensity (Z10%) decreased 27 cm in Béznar, 49 cm in Cubillas, and 69 cm in Quéntar due to the dust inputs. Therefore, the increasing dust export to the atmosphere may have consequences for the water transparency of aquatic ecosystems located under the influence of the global dust belt.This work was funded by the Spanish Ministry of Science and Technology (DISPAR, CGL2005-00076 to IR and CGL2008-06101/BOS to IdV) and by the Spanish Ministry of Education and Science (CICYT grant REN2003-03038 to RM-B)
Integración de competencias con temas en la enseñanza del grado de maestro. El maestro mecánico
La ficha de la asignatura de Teoría e Historia de la Educación para la formación de maestros de educación primaria y de educación infantil se halla en la web de la Facultad de Educación conteniendo los temas y competencias aprobados. Este recurso será el empleado para diseñar y efectuar la docencia y los procesos de evaluación, guiando a los estudiantes para optimizar sus capacidades. El reto del EEES no estriba sólo en confeccionar este instrumento informático, se procurará integrar en cada tema los tres ejes didácticos mediante el diseño correspondiente. Con el objeto de ofrecer unos lineamientos, en esta aportación a las jornadas de Redes-2014, trataremos de emplear el esquema confeccionado por Peiró (2013), para desarrollar la parte del tema, que versa sobre “La profesión docente”, mediante el enfoque de “modelos de maestro”, en el punto que explica la metáfora del maestro-mecánico (Peiró, 1999). Se procederá analógicamente al modelo que Peiró ideó para experimentarlo y que se expuso en su Tesis de la Licenciatura (1975), publicado en (1981, 230) como una vía metódica para llevar a cabo los niveles de relación interdisciplinaria con referencia a las sucesivas concreciones de objetivos y temas de la educación
Opinión de los Estudiantes sobre la Evaluación Efectuada en Teoría e Historia de la Educación
Uno de los pilares del Espacio Europeo de Educación Superior consiste en el establecimiento de criterios y metodologías pedagógicas comparables asegurando la calidad de los estudios universitarios. Desde este punto de vista, en la asignatura de Teoría e Historia de la Educación venimos implementando un nuevo sistema de evaluación final en el que integramos de forma transversal los temas con las competencias. Siguiendo esta premisa, el objetivo de este trabajo es conocer la opinión del alumnado sobre la prueba de evaluación final de la asignatura. Para ello, la metodología utilizada ha consistido en un cuestionario con el que se ha consultado a 206 alumnos/as. Como resultados más destacables podemos citar los problemas para la comprensión de las preguntas, la adecuación de las respuestas al espacio establecido para ello y el nivel de dificultad de la evaluación, que en general los alumnos califican como difícil. Mediante este estudio ponemos de manifiesto que la evaluación final de la asignatura no sólo es un instrumento para revisar lo aprendido por los alumnos sino también para ofrecerles retroalimentación para mejorar su educación, haciéndoles partícipes de la misma y posibilitando a los docentes la oportunidad de mejorarla
Modelling avalanches in martensites
Solids subject to continuous changes of temperature or mechanical load often
exhibit discontinuous avalanche-like responses. For instance, avalanche
dynamics have been observed during plastic deformation, fracture, domain
switching in ferroic materials or martensitic transformations. The statistical
analysis of avalanches reveals a very complex scenario with a distinctive lack
of characteristic scales. Much effort has been devoted in the last decades to
understand the origin and ubiquity of scale-free behaviour in solids and many
other systems. This chapter reviews some efforts to understand the
characteristics of avalanches in martensites through mathematical modelling.Comment: Chapter in the book "Avalanches in Functional Materials and
Geophysics", edited by E. K. H. Salje, A. Saxena, and A. Planes. The final
publication is available at Springer via
http://dx.doi.org/10.1007/978-3-319-45612-6_
Meso-Neoproterozoic basic-intermediate mafic granulites (metabasites) from the ∼1 Ga granulitic southwestern Oaxacan complex, Mexico, crustal evolution and phase equilibria modeling
Altres ajuts: acords transformatius de la UABThe basement of eastern Mexico is made up of Grenvillian granulite-facies metamorphic rocks, which constitute an inferred microcontinent named Oaxaquia. Proto-Oaxaquia oceanic arc reconstructions are related to the transition from Columbia to Rodinia supercontinents (∼1.5 Ga). This study focuses on the petrography, geochemistry, and phase equilibria modeling of metabasites from the southwestern Oaxacan Complex, the largest Oaxaquia outcrop. Southwestern Oaxacan Complex protoliths mainly correspond to gabbro/basalt. They constitute an assemblage apart from the rest of the Oaxacan Complex metabasites due to their Ti enrichment and SiO2 depletion related to post-magmatic/metamorphic processes. Southern study site metabasites correspond to the primitive root of the arc, mostly related to a divergent geotectonic setting. The other metabasites are related to the magmatic back/forearc active margin between proto-Oaxaquia and Amazonia craton. Phase equilibria modeling point to Zapotecan (last Grenvillian cycle) metamorphic peak conditions of 850 ± 25 °C and 1.0 ± 0.15 GPa from one garnet-amphibole bearing metabasite, and a later hydration episode (post-Grenvillian) of 760 ± 10 °C and 0.8 ± 0.20 GPa derived from one amphibole bearing metabasite. The time of incipient partial melting of the southwestern Oaxacan Complex is a pre-Zapotecan event (∼1 Ga). Mineral textures do not display significant processes related to the post-Zapotecan metamorphic retrogression, and only a few whole-rock light rare element patterns display strong enrichments
Light attenuation in Southern Iberian Peninsula reservoirs
[EN] This study evaluates the extinction coefficient of light (Kd) and the Secchi disk depth (SD) in 12 reservoirs located in the southern Iberian Peninsula. These systems show differences in landscape, physical, chemical and trophic properties. The relationships found were analyzed to evaluate the utility of the SD as predictor of the photic zone (Zeu) measured with Kd.The, a new equation is proposed here as a better estimation for the photic zone in these reservoirs: Zeu (m)≈ 2·SD (m)+6. The influence of the chlorophyll-a, turbidity and dissolved organic carbon (DOC) concentration on the water transparency is studied. Both DOC concentration and turbidity affect water transparency. Finally, the capacity of SD as a Kd predictor is also assessed.[ES] Este trabajo estudia de forma pareada los valores del coeficiente de extinción vertical de la luz (Kd) y de la profundidad de visión del disco de Secchi (SD) en un conjunto de 12 embalses del sureste de la Península Ibérica que difieren en sus características de paisaje, físicas, químicas y tróficas. Se analizan las relaciones encontradas para evaluar la utilidad del SD como predictor de la zona fótica (Zeu) calculada mediante Kd y se propone la expresión Zeu(m) ≈ 2·SD (m)+6 como una mejor estima de la zona fótica en estos embalses. Además se investiga la influencia de la clorofila-a, turbidez y carbono orgánico disuelto (DOC) sobre la transparencia del agua de los embalses. Tanto la concentración de DOC como la turbidez afectan a dichas propiedades. Finalmente, se analiza la capacidad de SD como predictor de Kd.La financiación para el presente trabajo fue obtenida del Ministerio de Economía y Competitividad, referencia: CGL2014-52362-R y fondos FEDER. E.L-P. cuenta con un contrato predoctoral de Formación del Profesorado Universitario (FPU014/02917). Los autores agradecen a los revisores los comentarios recibidos sobre el texto original al que han ayudado a mejorar.León-Palmero, E.; Reche, I.; Morales-Baquero, R. (2019). Atenuación de luz en embalses del sur-este de la Península Ibérica. Ingeniería del Agua. 23(1):65-75. https://doi.org/10.4995/ia.2019.10655SWORD6575231APHA. 1998. Methods for the Examination of Water and Wastewater. American Public Health AssociationBorowiak, D., Borowiak, M. 2016. Comparative studies of underwater light regimes in lakes of the East-Suwałki Lakeland. Limnological Review, 16(4), 173-183. https://doi.org/10.1515/limre-2016-0019Canteras, J.C., Pérez, L., León, P., Lorda, T. 1999. Efecto de la radiación luminosa en la desaparición de Escherichia coli (T90) en medio acuático. Estudio experimental. Ingeniería del Agua, 6(3), 269-274. https://doi.org/10.4995/ia.1999.2791Carlson, R.E. 1977. A trophic index for lakes. Limnology and Oceanography, 22, 361-369. https://doi.org/10.4319/lo.1977.22.2.0361Devlin, M.J., Barry, J., Mills, D.K., Gowen, R.J., Foden, J., Sivyer, D., Greenwood, N., Pearce, D., Tett, P. 2009. Estimating the diffuse attenuation coefficient from optically active constituents in UK marine waters. Estuarine, Coastal and Shelf Science, 82, 73-83. https://doi.org/10.1016/j.ecss.2008.12.015Dzieszko, P., Zwoliński, Z. 2015. Trophic diversity of Poznań Lakeland lakes. Limnological Review, 15(2), 61-69. https://doi.org/10.2478/limre-2015-0007French, R.H., Cooper, J.J., Vigg, S. 1982. Secchi disk relationships. Water Resources Bulletin, 18, 121-123. https://doi.org/10.1111/j.1752-1688.1982.tb04538.xHolmes, R.W. 1970. The Secchi disk in turbid coastal waters. Limnology and Oceanography, 15, 688-694. https://doi.org/10.4319/lo.1970.15.5.0688Koenings, J.P., Edmundson, J.A., 1991. Seechi disk and photometer estimates of light regimes in Alaskan lakes: effects of yellow color and turbidity. Limnology and Oceanography 36, 91-105. https://doi.org/10.4319/lo.1991.36.1.0091Ma, J., Song, K., Wen, Z., Zhao, Y., Shang, Y., Fang, C., Du, J. 2016. Spatial Distribution of Diffuse Attenuation of Photosynthetic Active Radiation and Its Main Regulating Factors in Inland Waters of Northeast China. Remote Sensing, 8, 964. https://doi.org/10.3390/rs8110964Morales-Baquero, R., Conde-Porcuna, J., Pérez-Martínez, C., Cruz-Pizarro, L. 1991. Vertical light attenuation in four reservoirs of Genil River (Granada, Spain). Proceedings of the 17th International Congress on Large Dams (ICOLD) (Q64, R9), 137-148.Morris, D.P., Zagarese, H., Williamson, C.E., Balseiro, E.G., Hargreaves, B.R., Modenutti, B., Moeller, R., Queimalinos, C. 1995. The attenuation of solar UV radiation in lakes and the role of dissolved organic carbon. Limnology and Oceanography, 40(8), 1381-1391. https://doi.org/10.4319/lo.1995.40.8.1381Poikane, S. 2009. Water Framework Directive.Intercalibration Technical Report. Part 2: Lakes. Office for Official Publications of the European Communities. Luxemburgo.Poole, H.H., Atkins,W.R. 1929. Photo-electric measurements of submarine illumination throughout the year. Journal of Marine Biological Association U.K. 16, 297-394. https://doi.org/10.1017/S0025315400029829Prats-Rodríguez, J., Morales-Baquero, R., Dolz-Ripollés, J., Armengol-Bachero, J. 2014. Aportaciones de la limnología a la gestión de embalses. Ingeniería del Agua, 18(1), 83-97. https://doi.org/10.4995/ia.2014.3145Rodríguez, J. 2016. Ecología. Pirámide. Madrid.Reche, I., Pace, M.L., Cole, J.J. 2000. Modeled Effects of Dissolved Organic Carbon and Solar Spectra on Photobleaching in Lake Ecosystems. Ecosystems, 3, 419-432.Scully N.M., Lean, D.R.S. 1994. The attenuation of ultraviolet light in temperate lakes. Ergebnisse der Limnologie, 43,135-144.Tundisi, J.C., Matsumura-Tundisi, T. 2011. Limnology. CRC Press, Boca-Ratón.USA
In silico Design of an Epitope-Based Vaccine Ensemble for Chagas Disease
Trypanosoma cruzi infection causes Chagas disease, which affects 7 million people
worldwide. Two drugs are available to treat it: benznidazole and nifurtimox. Although
both are efficacious against the acute stage of the disease, this is usually asymptomatic
and goes undiagnosed and untreated. Diagnosis is achieved at the chronic stage, when
life-threatening heart and/or gut tissue disruptions occur in ∼30% of those chronically
infected. By then, the drugs’ efficacy is reduced, but not their associated high toxicity.
Given current deficiencies in diagnosis and treatment, a vaccine to prevent infection
and/or the development of symptoms would be a breakthrough in the management
of the disease. Current vaccine candidates are mostly based on the delivery of single
antigens or a few different antigens. Nevertheless, due to the high biological complexity
of the parasite, targeting as many antigens as possible would be desirable. In this
regard, an epitope-based vaccine design could be a well-suited approach. With this
aim, we have gone through publicly available databases to identify T. cruzi epitopes
from several antigens. By means of a computer-aided strategy, we have prioritized a
set of epitopes based on sequence conservation criteria, projected population coverage
of Latin American population, and biological features of their antigens of origin. Fruit of
this analysis, we provide a selection of CD8+ T cell, CD4+ T cell, and B cell epitopes that
have <70% identity to human or human microbiome protein sequences and represent
the basis toward the development of an epitope-based vaccine against T. cruzi
Linking optical and molecular signatures of dissolved organic matter in the Mediterranean Sea
Original research paperDissolved organic matter (DOM) plays a key role in global biogeochemical cycles and experiences changes in molecular composition as it undergoes processing. In the semi-closed basins of the oligotrophic Mediterranean Sea, these gradual molecular modifications can be observed in close proximity. In order to extend the spatial resolution of information on DOM molecular composition available from ultrahigh resolution mass spectrometry in this area, we relate this data to optical (fluorescence and absorption spectroscopy) measurements. Covariance between molecular formulae signal intensities and carbon-specific fluorescence intensities was examined by means of Spearman’s rank correlations. Fifty two per cent of the assigned molecular formulae were associated with at least one optical parameter, accounting for 70% of the total mass spectrum signal intensity. Furthermore, we obtained significant multiple linear regressions between optical and intensity-weighted molecular indices. The resulting regression equations were used to estimate molecular parameters such as the double bond equivalent, degradation state and occurrence of unsaturated aliphatic compounds from optical measurements. The statistical linkages between DOM molecular and optical properties illustrate that the simple, rapid and cost-efficient optical spectroscopic measurements provide valuable proxy information on the molecular composition of open ocean marine DOM.y the project HOTMIX (grant number CTM2011-30010-C02-MAR) and the project FERMIO (MINECO, CTM2014-57334-JIN), both co-financed with FEDER fundsVersión del editor2,92
Compositional changes of PM2.5 in NE Spain during 2009–2018: a trend analysis of the chemical composition and source apportionment
In this work, time-series analyses of the chemical composition and source contributions of PM2.5 from an urban background station in Barcelona (BCN) and a rural background station in Montseny (MSY) in northeastern Spain from 2009 to 2018 were investigated and compared. A multisite positive matrix factorization analysis was used to compare the source contributions between the two stations, while the trends for both the chemical species and source contributions were studied using the Theil–Sen trend estimator. Between 2009 and 2018, both stations showed a statistically significant decrease in PM2.5 concentrations, which was driven by the downward trends of levels of chemical species and anthropogenic source contributions, mainly from heavy oil combustion, mixed combustion, industry, and secondary sulfate. These source contributions showed a continuous decrease over the study period, signifying the continuing success of mitigation strategies, although the trends of heavy oil combustion and secondary sulfate have flattened since 2016. Secondary nitrate also followed a significant decreasing trend in BCN, while secondary organic aerosols (SOA) very slightly decreased in MSY. The observed decreasing trends, in combination with the absence of a trend for the organic aerosols (OA) at both stations, resulted in an increase in the relative proportion of OA in PM2.5 by 12% in BCN and 9% in MSY, mostly from SOA, which increased by 7% in BCN and 4% in MSY. Thus, at the end of the study period, OA accounted for 40% and 50% of the annual mean PM2.5 at BCN and MSY, respectively. This might have relevant implications for air quality policies aiming at abating PM2.5 in the study region and for possible changes in toxicity of PM2.5 due to marked changes in composition and source apportionment
Evaluación del logro competencial en la asignatura Teoría e Historia de la Educación: procedimientos
La introducción de España en el Espacio Europeo de Educación Superior -EEES-, ha supuesto un cambio esencial en el proceso de enseñanza-aprendizaje. Así tenemos: la adecuación de las materias académicas a un lenguaje basado en la adquisición de competencias; revisión de la teoría y realidad mediante prácticas guiadas; reducción de la ratio alumnos/docente para dinamizar las actividades, centrarse más en el proceso que en el producto, sin menospreciar lo último; etc., todo relacionado con la definición de una serie de competencias, generales, específicas y propias de la Universidad de Alicante. Pero además de formalizar una metodología competencial, son necesarios también instrumentos que favorezcan tales innovaciones. Uno de ellos es el concerniente a la evaluación para medir en los alumnos los logros alcanzados. Este es el objeto de la investigación, cuyo resultado presentamos en Redes-UA-2016. En el presente trabajo analizamos diversas conceptualizaciones, procedimientos o modelos sobre autoevaluación, que nos permiten definir un instrumento para evaluar el logro competencial en Teoría e Historia de la Educación. Con esto promoveríamos la responsabilidad del alumno y la autoevaluación del docente, interpretando datos para detectar posibles desviaciones, para enmendar su desarrollo del programa
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