El delta de l'Ebre. 'El delta del Ebro'

Da a conocer el delta del Ebro con la finalidad de sensibilizarnos en cuanto a la necesidad de protegerlo y conservarlo. La interacci??n del r??o y el mar han configurado un paraje incomparable, declarado parque natural, para proteger las zonas v??rgenes y armonizarlas con los cultivos tradicionales del arroz y la huerta.

Camp d'Aprenentatge del Delta de l'Ebre. 'Campo de Aprendizaje del Delta del Ebro'

Los campos de aprendizaje son servicios educativos que ofrecen a los chicos y chicas la posibilidad de estar en un entorno singular en Catalu??a. Con la estancia en este campo de aprendizaje se pretende que los alumnos conozcan el Delta del Ebro. A partir de distintos itinerarios se descubre el paisaje y las caracter??sticas medio ambientales del entorno: el descenso del rio Ebro enbarca, una vuelta en bicicleta y un paseo por el entrono son los ejemplos de las actividades que se realizan en el campo de aprendizaje.

Delta i Marjal. 'Delta y Marjal'.

Define la particularidad geográfica de los Deltas de los ríos, muestra el proceso de formación y la vegetación característica que encontramos en estos parajes. Habla de la morfología de los suelos y de los cultivos más característicos como el arroz. Se refleja también la actividad ramadera en las marismas el Delta del Ebro.

Unidad didáctica interdisciplinar : El Ala Delta.

Unidad didáctica que responde a la necesidad de que los alumnos desarrollen y aprendan un conjunto de recursos eficaces para conocer mejor la realidad en la que viven y poder así actuar en y sobre ella. Las áreas que confluyen en el trabajo son: Geografía, Historia y Ciencias Sociales, Matemáticas, Ciencias de la Naturaleza e Informática. La duración prevista es de 60 horas y de 8 a 12 semanas. La unidad va a ser trabajada por alumnos de Lumbier (Navarra) que proceden de una zona netamente rural. Pretende dar respuesta al gran interés de estos jóvenes por conocer, comprender y enjuiciar rasgos y problemas que caracterizan a la zona de la que proceden y en la que previsiblemente van a vivir en un futuro. El proyecto se desarrolla a partir de sesiones de aula y salidas. Describe las actividades previstas que se dividen en los siguientes bloques: 1. Actividades para el conocimiento y comprensión del medio físico (utilización e interpretación de mapas topográficos y fotografías aéreas); 2. Actividades para el conocimiento y comprensión del medio natural (clima, geología, fauna, flora, ecosistemas, intervención humana, etc.); 3. Actividades para el conocimiento y comprensión del medio humano (fenómenos demográficos y elaboración de diagramas, gráficos, etc.); 4. Actividades para el conocimiento de la realidad agrícola, industrial y de servicios de la zona (localización, distribución y evolución de los sectores económicos, lectura e interpretación de documentos escritos referidos a las actividades económicas, etc.; 5. Actividades sobre el patrimonio artístico. Como introducción se presenta una simulación de un vuelo en ala delta (utilizando fotografía aérea y esteroscopio) con el objetivo de que el alumno observe y reconozca en los fotogramas los elementos que luego serán objeto de estudio y desarrollo en la unidad. Canaliza las preguntas que debe hacerse el alumno para que motivado por ellas, avance en el desarrollo de la unidad. Esta primera actividad es la de enfoque más globalizador. Se hizo una evaluación inicial de sondeo sobre los conocimientos, otra referida al progreso y al aprovechamiento por parte de los alumnos mediante la observación directa, los cuadernos de actividades y pruebas objetivas. Se evalua asímismo el proceso en cuanto a la oportunidad del diseño de la unidad, la secuencia de actividades y la actuación del profesor como motor del proceso.

La transformació del paisatge del delta de la Tordera en els darrers cent cinquanta anys : una anàlisi per mitjà dels canvis en els usos i les cobertes del sòl

This article compares the mid-nineteenth century landscape of the River Tordera delta with the present day landscape, based, above all, on the changes that have occurred in land use and land cover. The mid 19th century landscape was reconstructed using data obtained from the amillaraments (land inventories) and other historical documents. Present-day land use and cover was established through photo interpretation and field work. The most important changes detected concern the almost complete disappearance of certain crops, such as vineyards, which were very important in the 19th century; the expansion of forest in place of abandoned tilled land and the increase in built up areas, which, taken together, produce a highly fragmented landscape pattern

Delta cafés : prática de Responsabilidade Social ou Estratégia de Marketing Promocional?

Nesta dissertação será abordada a temática de Responsabilidade Social no ponto de vista teórico, as suas origens, dimensões, desenvolvimento, e a sua importância nos dias de hoje. Será igualmente abordado a importância do Livro Verde, livro este que promove um quadro europeu para a responsabilidade nas empresas. Com algum destaque, os media representam uma parte essencial para que a informação sobre a responsabilidade social chegue às partes interessadas bem como à sociedade. De certa forma, cabe aos media transmitir as suas vertentes, os eventos futuros, o que cada empresa fez ou faz (neste caso a empresa Delta Cafés) para promover as suas práticas de responsabilidade social. Bem como no ponto de vista prático, sendo o caso concreto da empresa Delta Cafés, será feita uma tentativa de articular a parte teórica da responsabilidade social, com o caso prático, que será a junção de ambos, tentando assim perceber se a empresa pratica realmente responsabilidade social ou se não passa de uma estratégia de marketing promocional.

Evaluating the Potential Impact of a Gas Pipeline on Whimbrel Breeding Habitat in the Outer Mackenzie Delta, Northwest Territories

We used ground surveys to identify breeding habitat for Whimbrel (Numenius phaeopus) in the outer Mackenzie Delta, Northwest Territories, and to test the value of high-resolution IKONOS imagery for mapping additional breeding habitat in the Delta. During ground surveys, we found Whimbrel nests (n = 28) in extensive areas of wet-sedge low-centered polygon (LCP) habitat on two islands in the Delta (Taglu and Fish islands) in 2006 and 2007. Supervised classification using spectral analysis of IKONOS imagery successfully identified additional areas of wet-sedge habitat in the region. However, ground surveys to test this classification found that many areas of wet-sedge habitat had dense shrubs, no standing water, and/or lacked polygon structure and did not support breeding Whimbrel. Visual examination of the IKONOS imagery was necessary to determine which areas exhibited LCP structure. Much lower densities of nesting Whimbrel were also found in upland habitats near wetlands. We used habitat maps developed from a combination of methods, to perform scenario analyses to estimate the potential effects of the Mackenzie Gas Project on Whimbrel habitat. Assuming effective complete habitat loss within 20 m, 50 m, or 250 m of any infrastructure or pipeline, the currently proposed pipeline development would result in loss of 8%, 12%, or 30% of existing Whimbrel habitat. If subsidence were to occur, most Whimbrel habitat could become unsuitable. If the facility is developed, follow-up surveys will be required to test these models.

The phytocannabinoid Delta(9)-tetrahydrocannabivarin modulates inhibitory neurotransmission in the cerebellum

Background and purposeThe phytocannabinoid Delta(9)-tetrahydrocannabivarin (Delta(9)-THCV) has been reported to exhibit a diverse pharmacology; here, we investigate functional effects of Delta(9)-THCV, extracted from Cannabis sativa, using electrophysiological techniques to define its mechanism of action in the CNS.Experimental approachEffects of Delta(9)-THCV and synthetic cannabinoid agents on inhibitory neurotransmission at interneurone-Purkinje cell (IN-PC) synapses were correlated with effects on spontaneous PC output using single-cell and multi-electrode array (MEA) electrophysiological recordings respectively, in mouse cerebellar brain slices in vitro.Key resultsThe cannabinoid receptor agonist WIN 55,212-2 (WIN55) decreased miniature inhibitory postsynaptic current (mIPSC) frequency at IN-PC synapses. WIN55-induced inhibition was reversed by Delta(9)-THCV, and also by the CB(1) receptor antagonist AM251; Delta(9)-THCV or AM251 acted to increase mIPSC frequency beyond basal values. When applied alone, Delta(9)-THCV, AM251 or rimonabant increased mIPSC frequency. Pre-incubation with Delta(9)-THCV blocked WIN55-induced inhibition. In MEA recordings, WIN55 increased PC spike firing rate; Delta(9)-THCV and AM251 acted in the opposite direction to decrease spike firing. The effects of Delta(9)-THCV and WIN55 were attenuated by the GABA(A) receptor antagonist bicuculline methiodide.Conclusions and implicationsWe show for the first time that Delta(9)-THCV acts as a functional CB(1) receptor antagonist in the CNS to modulate inhibitory neurotransmission at IN-PC synapses and spontaneous PC output. Delta(9)-THCV- and AM251-induced increases in mIPSC frequency beyond basal levels were consistent with basal CB(1) receptor activity. WIN55-induced increases in PC spike firing rate were consistent with synaptic disinhibition; whilst Delta(9)-THCV- and AM251-induced decreases in spike firing suggest a mechanism of PC inhibition.British Journal of Pharmacology advance online publication, 3 March 2008; doi:10.1038/bjp.2008.57.

Seasonality of delta C-13 and C/N ratios in modern and mid-holocene sediments in the Severn Estuary levels, SW Britain

Bulk organic VC and C/N ratios from mid-Holocene salt-marsh deposits with sedimentary banding reveal subtle but significant differences between coarse- and fine-grained deposits. These are consistent with findings from seasonally sampled modern silts, and with the interpretation, on physical and palynological grounds, of the fine-grained and coarse-grained components as warm-season and cold-season deposits, respectively. The control is considered to be seasonal variations in the character of the organic matter supplied.

Evolution of the modern Nile delta promontories: development of accretional features during shoreline retreat

The active accretional features that have developed along the modern Nile Delta promontories during shoreline retreat are analysed using topographic maps, remote imagery, ground and hydrographic surveys, together providing 15 time-slice maps (1922-2000) at Rosetta and 14 time-slice maps (1909-2000) at Damietta. Small double sandy spits developed and persisted at Rosetta between 1986 and 1991. At Damietta, a much larger single spit, 9 km long, formed approximately east of the mouth of the Damietta Nile branch between 1955 and 1972, although its source has now been depleted. Both the Rosetta and Damietta inlets are associated with submerged mouth bars that accumulated prior to the damming of the Nile, but that continue to contribute to local sedimentation problems, particularly at Rosetta. The development of the active accretional features along the Nile promontories reflects a combination of factors including sediment availability, transport pathways from source areas, a decrease in the magnitude of Nile flood discharges, as well as the impact of protective structures at the river mouths.

Arthropod diversity and community structure in relation to land use in the mekong delta, vietnam

Declining biodiversity in agro-ecosystems, caused by intensification of production or expansion of monocultures, is associated with the emergence of agricultural pests. Understanding how land-use and management control crop-associated biodiversity is, therefore, one of the key steps towards the prediction and maintenance of natural pest-control. Here we report on relationships between land-use variables and arthropod community attributes (for example, species diversity, abundance and guild structure) across a diversification gradient in a rice-dominated landscape in the Mekong delta, Vietnam. We show that rice habitats contained the most diverse arthropod communities, compared with other uncultivated and cultivated land-use types. In addition, arthropod species density and Simpson's diversity in flower, vegetable and fruit habitats was positively related to rice cover in the local landscape. However, across the landscape as a whole, reduction in heterogeneity and the amount of uncultivated cover was associated, generally, with a loss of diversity. Furthermore, arthropod species density in tillering and flowering stages of rice was positively related to crop and vegetation richness, respectively, in the local landscape. Differential effects on feeding guilds were also observed in rice-associated communities with the proportional abundance of predators increasing and the proportional abundance of detritivores decreasing with increased landscape rice cover. Thus, we identify a range of rather complex, sometimes contradictory patterns concerning the impact of rice cover and landscape heterogeneity on arthropod community attributes. Importantly, we conclude that that land-use change associated with expansion of monoculture rice need not automatically impact diversity and functioning of the arthropod community.

Supramolecular parallel beta-sheet and amyloid-like fibril forming peptides using delta-aminovaleric acid residue

Four terminally blocked tripeptides containing delta-aminovaleric acid residue self-assemble to form supramolecular beta-sheet structures as are revealed from their FT-IR data. Single crystal X-ray diffraction studies of two representative peptides also show that they form parallel beta-sheet structures. Self-aggregation of these beta-sheet forming peptides leads to the formation of fibrillar structures, as is evident from scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images. These peptide fibrils bind to a physiological dye, Congo red and exhibit a typical green-gold birefringence under polarized light, showing close resemblance to neurodegenerative disease causing amyloid fibrils. (c) 2005 Elsevier Ltd. All rights reserved.