Ericoid mycorrhiza:A partnership that exploits harsh edaphic conditions

Plants that form ericoid mycorrhizal associations are widespread in harsh habitats. Ericoid mycorrhizal fungal endophytes are a genetically diverse group, and they appear to be able to alleviate certain environmental stresses and so facilitate the establishment and survival of Ericaceae. Some of the fungal taxa that form ericoid mycorrhizas, or at least closely related strains, also form associations with other plant hosts (trees and leafy liverworts). The functional significance of these associations and putative mycelial links between Ericaceae and other plant taxa, however, remain unclear. Evidence from environments that are contaminated by toxic metals indicates that ericoid mycorrhizal fungal endophytes, and in some instances their plant hosts, can evolve resistance to these metals. The apparent ability of these endophytes to develop resistance enables ericoid mycorrhizal plants to colonize polluted soil. This seems to be a major factor in the success of ericoid mycorrhizal taxa in a range of harsh environments.

Edaphic factors affecting the toxicity and accumulation of arsenate in the earthworm Lumbricus terrestris

The toxicity and accumulation of arsenate was determined in the earthworm Lumbricus terrestris in soil from different layers of a forest profile. Toxicity increased fourfold between 2 and 10 d. Edaphic factors (pH, soil organic matter, and depth in soil profile) also affected toxicity with a three fold decrease in the concentration that causes 50% mortality with increasing depth in soil (from 0-70 mm to 500-700 mm). In a 4-d exposure study, there was no evidence of arsenic bioconcentration in earthworm tissue, although bioaccumulation was occurring. There was a considerable difference in tissue residues between living and dead earthworms, with dead worms having higher concentrations. This difference was dependent on both soil arsenate concentration and on soil type. Over a wide range of soil arsenate concentrations, earthworm arsenic residues are homeostatically maintained in living worms, but this homeostasis breaks down during death. Alternatively, equilibration with soil residues may occur via accumulation after death. In long-term accumulation studies in soils dosed with a sublethal arsenate concentration (40 μg/g dry weight), bioconcentration of arsenate did not occur until day 12, after which earthworm concentrations rose steadily above the soil concentration, with residues in worms three fold higher than soil concentrations by the termination of the study (23 d). This bioconcentration only occurred in depurated worms over the time period of the study. Initially, depurated worms had lower arsenic concentrations than undepurated until tissue concentrations were equivalent to the soil concentration. Once tissue concentration was greater than soil concentration, depurated worms had higher arsenic residues than undepurated.

MCMI-II borderline personality disorder in anorexia and bulimia nervosa. 'Trastorno l??mite de personalidad seg??n el MCMI-II en la anorexia y bulimia nerviosas'

Resumen tomado de la publicaci??n

Sentit pedagògic del mite de la bèstia enamorada. 'Sentido pedagógico del mito de la bestia enamorada'.

El tema de la bestia enamorada es frecuente en los cuentos de todas las culturas. No siempre se trata de un animal sino que el enamorado suele adoptar formas mostruosas y feroces. Partiendo del psicoanálisis, se ha demostrado la acción liberadora que ejercen los cuentos populares en la formación de la personalidad infantil y en la maduración de la afectividad, el enriquecimiento del lenguaje y la imaginación, la educación de la atención pero sobre todo la capacidad que poseen para favorecer el conocimiento y superar los propios problemas emocionales a través de recrearlos en los cuentos. El coraje es sin duda uno de los valores que con más insistencia ofrecen los cuentos populares: la aventura iniciática es siempre un reto, un riesgo a los ojos del protagonista para que sea capaz de correr las peripecias llenas de intriga que la historia le plantea. Pero sobre todo lo que es más destacable en los cuentos es que sus mensajes llegan a través de simples y cotidianas situaciones sociales, como el mito de la bestia enamorada sirve para cambiar la actitud de la mujer frente al sexo, para pasar del sentimiento de rechazo y miedo a la aceptación.

Sentit pedagògic del mite de la bèstia enamorada. 'Sentido pedagógico del mito de la bestia enamorada'.

Resumen tomado de la publicación

El Montseny i les Guilleries : paisatge, mite i literatura. 'El Montseny y las Guilleries : paisaje, mito y literatura'

Resumen del v??deo en catal??n

Mitologia : l'antropologia a través del mite. 'Mitología : la antropología a través del mito'.

Trabajo que analiza los mitos y las leyendas que han creado los distintos pueblos y culturas del mundo en su intento de dar respuesta a las preguntas que a lo largo de los siglos se ha planteado la humanidad. Asi el capítulo segundo estudia los dioses y héroes de la mitología china, africana, árabe, inca, vikinga y helénica. Para finalizar con una cronología, documentos y bibliografía, así como con una serie de actividades y juegos para una mejor comprensión del tema..

El CAP : tr??mite y exigencia

El matricularse en el CAP es simplemente un tr??mite burocr??tico y obligatorio. Exigible para dar clases y opositar. Est?? condenado a vivir sin ser curso de aptitud pedag??gica. Si este curso es necesario y requiere una organizaci??n hay que organizarlo bien, con profesores competentes que supervisen de modo constante las practicas, programaciones y resultados de su actividad. La memoria es un tr??mite es un tramite molesto e innecesario que se deber??a suprimir. La ruina del CAP no viene de ensayar f??rmulas nuevas, sino de querer mantener a toda costa una estructura caduca y cara, adem??s de inoperante e in??til.

Definiciones personales y aspectos estructurales del concepto de l??mite finito de una funci??n en un punto

Resumen basado en el de la publicaci??n

La regulaci??n de las titulaciones universitarias oficiales como??l??mite a la descentralizaci??n en la Educaci??n Superior

Resumen basado en el de la publicaci??n

Rousseau, tres-cents anys despr??s : entre el mite i la realitat

Resumen basado en el de la publicaci??n

Acampar sin permiso, pensar sin l??mite : evaluaci??n del proceso de un estudio de caso sobre el 15M (Granada)

Monogr??fico con el t??tulo: "Otra investigaci??n es posible"

La deixa del mite grec en la literatura contempor??nia

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Edaphic influences on plant community adaptation in the Chiquibul forest of Belize

Edaphic variables figure significantly in plant community adaptations in tropical ecosystems but are often difficult to resolve because of the confounding influence of climate. Within the Chiquibul forest of Belize, large areas of Ultisols and Inceptisols occur juxtaposed within a larger zone of similar climate, permitting unambiguous assessment of edaphic contributions to forest composition. Wet chemical analyses, X-ray diffraction and X-ray fluorescence spectroscopy were employed to derive chemical (pH, exchangeable cations, CEC, total and organic C, total trace elements) and physical (texture, mineralogy) properties of four granite-derived Ustults from the Mountain Pine Ridge plateau and four limestone-derived Ustepts from the San Pastor region. The soils of these two regions support two distinct forests, each possessing a species composition reflecting the many contrasting physicochemical properties of the underlying soil. Within the Mountain Pine Ridge forest, species abundance and diversity is constrained by nutrient deficiencies and water-holding limitations imposed by the coarse textured, highly weathered Ultisols. As a consequence, the forest is highly adapted to seasonal drought, frequent fires and the significant input of atmospherically derived nutrients. The nutrient-rich Inceptisols of the San Pastor region, conversely, support an abundant and diverse evergreen forest, dominated by Sabal mauritiiformis, Cryosophila stauracantha and Manilkara spp. Moreover, the deep, fine textured soils in the depressions of the karstic San Pastor landscape collect and retain during the wet season much available water, thereby serving as refugia during particularly long periods of severe drought. To the extent that the soils of the Chiquibul region promote and maintain forest diversity, they also confer redundancy and resilience to these same forests and, to the broader ecosystem, of which they are a central part. (C) 2005 Elsevier B.V. All rights reserved.