5,616 research outputs found
Residual effect of natural and synthetic zinc chelates on zinc in a soil solution of a waterlogged acidic soil. Evolution of the pH and redox potential.
Zinc chelates have been widely used to correct deficiencies in this micronutrient in different soil types and under different moisture conditions. The aging of the metal in soil could cause a change in its availability. Over time the most labile forms of Zn could decrease in activity and extractability and change to more stable forms. Various soil parameters, such as redox conditions, time, soil type and moisture conditions, affect the aging process and modify the solubility of the metal. In general, redox conditions influence pH and also the chemical forms dissolved in the soil solution. Soil pH also affects Zn solubility; at high pH values, most of the Zn is present in forms that are not bioavailable to plants. The objective of this study was to determine the changes in Zn over time in a soil solution in a waterlogged acidic soil to which synthetic and natural chelates were applie
Isoperimetric inequalities in Riemann surfaces of infinite type
75 pages, 1 figure.-- MSC2000 code: 30F45.MR#: MR1715412 (2000j:30075)Zbl#: Zbl 0935.30028Research partially supported by a grant from Dirección General de Enseñanza Superior (Ministerio de Educación y Ciencia), Spain.Publicad
The emotional values in the initial training of education students. An initial study
El objetivo de este artículo es intentar una aproximación a la concepción que sobre la afectividad tienen los alumnos de la Facultad de Ciencias de la Educación (Granada) y las Facultades de Educación y Humanidad de Ceuta y Melilla. Partimos de la base de que la afectividad es una dimensión esencial en la educación y como tal, es importante constatar su vigencia en los futuros docentes en formación. Desde este marco construimos un instrumento en el que se reflejan todas las dimensiones de la persona
(intelectual, corporal, afectiva, individual, etc), comprobando la jerarquía de
valores del alumnado y qué papel desempeña la afectividad. Terminamos
ofreciendo los resultados obtenidos, reflejando la preferencia del alumnado por los valores afectivos.The objective of this article is to attempt an approach to the conception of affection of the students of the School of Education Sciences (University of Granada) and the School of Education and Humanity of Ceuta and Melilla. We will begin from the base that the affection is an essential dimension of education and as such, it is important to note its validity for the future educators in training. From this framework, we build an instrument in which all the dimensions of a person is reflected (intellectual, corporal, affective, singular, etc), checking the hierarchy of values of the pupil and the role for which affection carries out. We will finish by offering the obtained results, showing the preference of the pupil for the various affective values
Estructura institucional y organización territorial local en España: fragmentación municipal, asociacionismo confuso, grandes ciudades y provincias supervivientes
This paper offers a vision of the local structures in Spain, a country with a large number of municipalities (more than 8.110) without any policy addressed to the rationalization and simplification of such fragmentation. The local associationism has proved to be a mostly anarchic movement, where municipalities make arrangements for very different reasons and delivering all kind of services, but without a common pattern. Even more, a large number of “mancomunidades” (voluntary associations of municipalities) actually doesn’t work and exists only in theory. This fragmented local map is very unbalanced because almost 40 per cent of the Spanish population lives in a small group of 62 municipalities with more than 100,000 inhabitants, which represent the core of the local power in Spain. The traditionally uniform Spanish local legal framework –based in the French model- has introduced for the first time a specific model for the largest cities in 2003, taking into account the complexity of their government and governance context. Also the two main Spanish cities –Madrid and Barcelona– have special laws approved by the Spanish Parliament in 2006. Nevertheless, the Spanish functional metropolitan areas present a low institutional profile due to the resistance of the Autonomous Communities –the regional level with legislative powers to establish or suppress them– to institutionalize these urban areas as they are perceived mostly as political competitors. Finally, the traditional second local level, the province, has experienced a substantial cutback of its competences after the establishment of the Autonomous Communities in 1979-1983. In theory, the main role of the province is the economical, technical and legal cooperation with the small and medium size municipalities, but actually this role could be implemented by the Autonomous Communities, and the provinces means an arena for the political clientelism and a privileged and comfortable space for the local political elites that could perfectly be suppressed, especially in a context of deep economic crisis and reduction of public resources.Este artículo ofrece una visión de las estructuras locales en España, un país con un gran número de municipios (más de 8.110) pero sin una política dirigida a la racionalización y simplificación de esa fragmentación. El asociacionismo local ha acreditado ser un movimiento demasiado anárquico, en el que los municipios celebran acuerdos por razones muy diversas y prestan todo tipo de servicios, pero sin una pauta común. Peor aún, un gran número de mancomunidades realmente no funcionan y sólo existen sobre el papel. Este mapa local fragmentado es muy desequilibrado porque casi el 40 por ciento de las población española reside en un pequeño grupo de 62 municipios con más de 100.000 habitantes, que representan el núcleo del poder local en España. El tradicionalmente uniforme mapa local español, basado en el modelo francés, ha introducido por ver primera un modelo específico para las grandes ciudades en 2003, teniendo en cuenta la complejidad de su gobierno y su contexto de gobernanza. También las dos principales ciudades españolas –Madrid y Barcelona– disponen de leyes especiales aprobadas por las Cortes Generales en 2006. Sin embargo, las áreas metropolitanas funcionales españolas presentan un bajo perfil institucional debido a la resistencia de las Comunidades Autónomas –el nivel político regional con potestades legislativas para crearlas o suprimirlas– para institucionalizar esas áreas urbanas, que son percibidas como potenciales competidores políticos. Finalmente, el tradicional segundo nivel local, la provincia, ha experimentado un sustancial recorte de sus competencias tras la creación de las Comunidades Autónomas en 1979-1983. En teoría, el principal papel de la provincia es la cooperación económica, técnica y jurídica con los municipios pequeños y medios, pero realmente este papel puede ser perfectamente desempeñado por las Comunidades Autónomas y la provincia representa de hecho un terreno para el clientelismo político y un espacio privilegiado y confortable para las élites políticas locales que perfectamente puede suprimirse, especialmente en el contexto de una profunda crisis económica y de reducción de los recursos públicos
Approximation theory for weighted Sobolev spaces on curves
17 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.MR#: MR1882649 (2003c:42002)In this paper we present a definition of weighted Sobolev spaces on curves and find general conditions under which the spaces are complete. We also prove the density of the polynomials in these spaces for non-closed compact curves and, finally, we find conditions under which the multiplication operator is bounded on the completion of polynomials. These results have applications
to the study of zeroes and asymptotics of Sobolev orthogonal polynomials.Research of V. Álvarez, D. Pestana and J.M. Rodríguez partially supported by a grant from
DGI, BFM2000-0206-C04-01, Spain.Publicad
Generalized weighted Sobolev spaces and applications to Sobolev orthogonal polynomials, I
36 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.-- Part II of this paper published in: Approx. Theory Appl. 18(2): 1-32 (2002), available at: http://e-archivo.uc3m.es/handle/10016/6483MR#: MR2047389 (2005k:42062)Zbl#: Zbl 1081.42024In this paper we present a definition of Sobolev spaces with respect to general measures, prove some useful technical results, some of them generalizations of classical results with Lebesgue measure and find general conditions under which these spaces are complete. These results have important consequences in approximation theory. We also find conditions under which the evaluation operator is bounded.Research by first (J.M.R.), third (E.R.) and fourth (D.P.) authors was partially supported by a grant from DGI (BFM 2000-0206-C04-01), Spain.Publicad
Estudio bibliométrico e indicadores de calidad metodológicos de la revista Porta Lin- guarum durante el sexenio 2008-2013
In this study we have developed a bibliometric study in the journal Porta
Linguarum about the methodological quality indicators of the empirical articles published
during the sexennial period 2008-2013. The results obtained show that, it was a journal in
which quantitative papers predominate along with theoretical works. The results also suggest
that, this journal should improve some fundamental methodological issues, related mainly to
the types of samples, novelty of the literature and validity and reliability of the data collection instruments. On the contrary, it has achieved excellent results in the indicators related to
the internationality of authorship and references managed, language processing, and control
of inbreeding for authorship.En el presente trabajo hemos desarrollado un estudio bibliométrico de la revista Porta Linguarum sobre indicadores de calidad metodológicos de los artículos de naturaleza empírica publicados durante el sexenio 2008-¬2013. Los resultados logrados revelan que se trata de una revista donde predominan los trabajos de corte cuantitativo, junto a otros de carácter más teórico. Los datos obtenidos, también apuntan a que la revista citada debe mejorar algunos aspectos metodológicos esenciales, relacionados, sobre todo, con la tipología de muestreos, novedad de las referencias bibliográficas y criterios de calidad de los instrumentos de medida. Por el contrario, ha logrado excelentes resultados en los indicadores sobre internacionalidad de las autorías y las referencias bibliográficas manejadas, idioma de elaboración, así como en el control de la endogamia por autoría
Weighted Sobolev spaces on curves
45 pages, no figures.-- MSC1987 codes: 41A10, 46E35, 46G10.MR#: MR1934626 (2003j:46038)Zbl#: Zbl 1019.46026In this paper we present a definition of weighted Sobolev spaces on curves and find general conditions under which the spaces are complete for non-closed compact curves. We also prove the density of the polynomials in these spaces and, finally, we find conditions under which the multiplication operator is bounded in the space of polynomials.Research of second (D.P.), third (J.M.R.) and fourth (E.R.) authors was partially supported by a grant from DGI (BFM 2000-0206-C04-01), Spain.Publicad
Generalized weighted Sobolev spaces and applications to Sobolev orthogonal polynomials, II
32 pages, no figures.-- MSC1987 codes: 41A10, 46E35, 46G10.-- Part I of this paper published in: Acta Appl. Math. 80(3): 273-308 (2004), available at: http://e-archivo.uc3m.es/handle/10016/6482MR#: MR1928169 (2003h:42034)Zbl#: Zbl 1095.42014^aWe present a definition of general Sobolev spaces with respect to arbitrary measures, for . In Part I [Acta Appl. Math. 80(3): 273-308 (2004), http://e-archivo.uc3m.es/handle/10016/6482] we proved that these spaces are complete under very mild conditions. Now we prove that if we consider certain general types of measures, then is dense in these spaces. As an application to Sobolev orthogonal polynomials, we study the boundedness of the multiplication operator. This gives an estimation of the zeroes of Sobolev orthogonal polynomials.Research partially supported by a grant from DGES (MEC), Spain.Publicad
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