339 resultados para Delmarva Bays


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3.050 JCR (2013) Q2, 44/125 Cardiac & cardiovascular systems

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We present a search for nonzero θ13 and deviations of sin2θ23 from 0.5 in the oscillations of atmospheric neutrino data from Super-Kamiokande I, II, and III. No distortions of the neutrino flux consistent with nonzero θ13 are found and both neutrino mass hierarchy hypotheses are in agreement with the data. The data are best fit at Δm2=2.1×10-3eV2, sin2θ13=0.0, and sin2θ23=0.5. In the normal (inverted) hierarchy θ13 and Δm2 are constrained at the one-dimensional 90% C.L. to sin2θ13<0.04(0.09) and 1.9(1.7)×10 -3<Δm2<2.6(2.7)×10-3eV2. The atmospheric mixing angle is within 0.407≤sin2θ23≤0.583 at 90% C.L. © 2010 The American Physical Society.

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Poultry litter contains high levels of natural sex hormones, nitrogen, phosphorous, and trace amounts of heavy metals. Poultry litter runoff from poultry and farming operations in the Delmarva region can have serious impacts on frog development in the Chesapeake Bay Watershed. In this study, we investigated potential effects of litter compounds on Xenopus laevis development when exposed to environmental levels (0.35 and 0.70 g/L) of litter solution. We found that despite rapid hormone degradation, poultry litter solution still affected X. laevis development. Hormones were also more persistent in the lower poultry litter concentration, leading to even greater effects. Slowed growth and increased female gonadal abnormalities were observed after exposure to 0.35 g/L but not to 0.70 g/L of litter solution, and increased male gonadal abnormalities were observed after treatment to both litter concentrations. The developmental impacts examined in this study may have greater environmental impacts on frog reproduction and survival.

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Two recently-distinguished species of Chthamalus (Cirripedia) are found on rocky shores in the north-eastern Atlantic: C. stellatus predominant on islands and headlands and C. montagui more abundant in bays. Larvae of the two species were produced in laboratory cultures to describe and compare the morphology and to allow identification in plankton samples. Nauplius larvae of C. stellatus are up to 30% larger than those of C. montagui. Differences in setation are minor. The two species are easily distinguishable from the size and shape of the cephalic shield. Chthamalus stellatus has a subcircular shield with longer body processes in later stages while C. montagui is more ovoid. The former develop more slowly in culture than the latter. Chthamalus stellatus larvae in a culture at 19 °C reached stage VI in 16 d compared to 11 d for larvae of C. montagui at the same temperature. The morphology and longer development time of C. stellatus larvae suggests adaptation to a more oceanic lifestyle and wider dispersal to reach more fragmented habitats than larvae of C. montagui. --------------------------------------------------------------------------------

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Semi-enclosed bays in upwelling regions are exposed to forcing related to winds, currents and buoyancy over the shelf. The influence of this external forcing is moderated by factors such as connectivity to the open ocean, shelter by surrounding topography, dimensions of the bay, and freshwater outflows. Such bays, preferred locations for ports, mariculture, marine industry, recreational activities and coastal settlement, present a range of characteristics, understanding of which is necessary to their rational management. Observations in such a semi-enclosed bay, the Ria de Vigo in Spain, are used to characterize the influence of upwelling and downwelling pulses on its circulation. In this location, near the northern limit of the Iberian upwelling system, upwelling events dominate during a short summer season and downwelling events the rest of the year. The ria response to the external forcing is central to nutrient supply and resultant plankton productivity that supports its high level of cultured mussel production. Intensive field studies in September 2006 and June 2007 captured a downwelling event and an upwelling event, respectively. Data from eight current profiler moorings and boat-based MiniBat/ADCP surveys provided an unprecedented quasi-synoptic view of the distribution of water masses and circulation patterns in any ria. In the outer ria, circulation was dominated by the introduction of wind-driven alongshore flow from the external continental shelf through the ria entrances and its interaction with the topography. In the middle ria, circulation was primarily related to the upwelling/downwelling cycle, with a cool, salty and dense lower layer penetrating to the inner ria during upwelling over the shelf. A warmer, lower salinity and less dense surface layer of coastal waters flowed inward during downwelling. Without external forcing, the inner ria responded primarily to tides and buoyancy changes related to land runoff. Under both upwelling and downwelling conditions, the flushing of the ria involved shelf responses to wind pulses. Their persistence for a few days was sufficient to allow waters from the continental shelf to penetrate the innermost ria. Longer term observations supported by numerical modeling are required to confirm the generality of such flushing events in the ria and determine their typical frequency, while comparative studies should explore how these scenarios fit into the range of conditions experienced in other semi-enclosed bays.

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The richness and turnover of coastal larval pools set upper limits for biodiversity in coastal systems. For particular local systems, such as embayments, the characteristics of the local larval pool are determined by the relative contributions of locally produced and external larvae. The balance between these sources partially reflects the extent of tidal exchange and is hence related to system size and flushing time. Larvae of benthic marine invertebrates were sampled from 8 bays along the Irish coast to investigate the effect of coastline configuration on the characteristics of the larval pool. Flushing time explained 34.5% of the variability in species richness from a series of daily samples. Many of the potentially relevant environmental variables are correlated, limiting the potential for individual variables to be examined in isolation. We therefore used a principal components analysis to describe the major patterns in environmental variability across bays. The second principal component separated bays along a gradient of increasing depth, salinity, tidal range and flushing time. Scores along this component were generally better predictors of the larval pool than single variables, explaining as much as 61.2% of the variation in species richness, diversity and similarity between dates. Deeper bays, with more saline water and longer flushing times, tended to have richer and more diverse larval pools, with a greater consistency in species composition between sample dates. No relationship was found between environmental variables and larval abundance. Our results suggest that flushing time, particularly when in combination with topographic variables, chlorophyll, tidal range and salinity, may be a useful predictor for the richness and turnover of local larval pools.

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Assembling aircraft stiffened panels using friction stir welding offers potential to reduce fabrication time in comparison to current mechanical fastener assembly, making it economically feasible to select structurally desirable stiffener pitching and novel panel configurations. With such a departure from the traditional fabrication process, much research has been conducted on producing strong reliable welds, with less examination of the impact of welding process residual effects on panel structural behaviour and the development of appropriate design methods. This article significantly expands the available panel level compressive strength knowledge, demonstrating the strength potential of a welded aircraft panel with multiple lateral and longitudinal stiffener bays. An accompanying computational study has determined the most significant process residual effects that influence panel strength and the potential extent of panel degradation. The experimental results have also been used to validate a previously published design method, suggesting accurate predictions can be made if the conventional aerospace design methods are modified to acknowledge the welding altered panel properties.

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With the increase in construction in dense urban environments, the delays associated with managing the material supply chain to site is called into question. Purpose: The aim of this investigation is to gain the perspective of construction contractors operating in a dense urban environment and the resulting strategies adopted to reduce delays in the delivery of materials to site. Methodology: This is achieved through incorporating a comprehensive literature review on the subject in conjunction with industry interviews with construction professionals in the identification of various management issues and corresponding strategies in the reduction of delays in the delivery of materials to site. Findings: The key issue which emerges is the lack of space for unloading bays while the corresponding key strategy is to schedule deliveries outside peak congestion times. Practical Implication: With confined site construction evident throughout the industry and the noted importance of an effective supply chain, the findings here in further assist on-site management in the daily task of ensuring the effective delivery and off-loading of materials in a complex and hazardous environment. Originality/Value: This research aids on-site management of confined site environments in the coordination of the material supply chain to site.

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Protein G-coated magnetic particles (MPs) were used as immobilisation supports for an antibody against okadaic acid (MAb(OA)) and carriers into a surface plasmon resonance (SPR) device for the development of a direct competitive immunosensor for okadaic acid (OA). SPR analysis of MAb(OA)-MP conjugates demonstrated that conjugations were successful with complete immobilisation of all the antibody biomolecules onto the MPs. Moreover, MAb(OA)-MP conjugates provided up to 11-fold higher SPR signals, compared to free MAb(OA). The use of conjugates in the direct competition assay provided a 3-fold lower LOD mu g/L (2.6 mu g of OA/L, equivalent to 12 mu g of OA/kg mussel meat). The presence of mussel matrix did not interfere in the OA quantification as seen in the calibration curves. Mussel samples, obtained from Ebro Delta's bays (NW Mediterranean) during a diarrheic shellfish poisoning (DSP) event and in the presence of Dinophysis sacculus, an OA producer, in the shellfish production area, were analysed with the MP-based SPR immunosensor. The OA contents correlated with those obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (y = 0.984x -5.273, R-2 = 0.789, p <0.001) and by mouse bioassay (MBA).

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ecosystems. Coastal oceanic upwelling, for example, has been associated with elevatedbiomass and abundance patterns of certain functional groups, e.g., corticated macroalgae.In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthiccomposition, structure and trophic ecology across eighteen shores varying in theirproximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scalesof >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmedby the stable isotope values (δ13C and δ15N) of consumers, including a dominantsuspension feeder, grazers, and their putative resources of POM, epilithic biofilm, andmacroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel,Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previousstudies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation,ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Ourresults showed macroalgal assemblage composition, and benthic consumer assemblagestructure, varied significantly with the intertidal influence of coastal upwelling, especiallycontrasting bays and coastal headlands. Coastal topography also separated differences inconsumer resource use. This suggested that coastal upwelling, itself driven by coastlinetopography, influences intertidal communities by advecting nearshore phytoplankton populationsoffshore and cooling coastal water temperatures. We recommend the isotopic valuesof benthic organisms, specifically long-lived suspension feeders, as in situ alternativesto offshore measurements of upwelling influence

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This paper explores the theme of exhibiting architectural research through a particular example, the development of the Irish pavilion for the 14th architectural biennale, Venice 2014. Responding to Rem Koolhaas’s call to investigate the international absorption of modernity, the Irish pavilion became a research project that engaged with the development of the architectures of infrastructure in Ireland in the twentieth and twenty-first centuries. Central to this proposition was that infrastructure is simultaneously a technological and cultural construct, one that for Ireland occupied a critical position in the building of a new, independent post-colonial nation state, after 1921.

Presupposing infrastructure as consisting of both visible and invisible networks, the idea of a matrix become a central conceptual and visual tool in the curatorial and design process for the exhibition and pavilion. To begin with this was a two-dimensional grid used to identify and order what became described as a series of ten ‘infrastructural episodes’. These were determined chronologically across the decades between 1914 and 2014 and their spatial manifestations articulated in terms of scale: micro, meso and macro. At this point ten academics were approached as researchers. Their purpose was twofold, to establish the broader narratives around which the infrastructures developed and to scrutinise relevant archives for compelling visual material. Defining the meso scale as that of the building, the media unearthed was further filtered and edited according to a range of categories – filmic/image, territory, building detail, and model – which sought to communicate the relationship between the pieces of architecture and the larger systems to which they connect. New drawings realised by the design team further iterated these relationships, filling in gaps in the narrative by providing composite, strategic or detailed drawings.

Conceived as an open-ended and extendable matrix, the pavilion was influenced by a series of academic writings, curatorial practices, artworks and other installations including: Frederick Kiesler’s City of Space (1925), Eduardo Persico and Marcello Nizzoli’s Medaglio d’Oro room (1934), Sol Le Witt’s Incomplete Open Cubes (1974) and Rosalind Krauss’s seminal text ‘Grids’ (1979). A modular frame whose structural bays would each hold and present an ‘episode’, the pavilion became both a visual analogue of the unseen networks embodying infrastructural systems and a reflection on the predominance of framed structures within the buildings exhibited. Sharing the aspiration of adaptability of many of these schemes, its white-painted timber components are connected by easily-dismantled steel fixings. These and its modularity allow the structure to be both taken down and re-erected subsequently in different iterations. The pavilion itself is, therefore, imagined as essentially provisional and – as with infrastructure – as having no fixed form. Presenting archives and other material over time, the transparent nature of the space allowed these to overlap visually conveying the nested nature of infrastructural production. Pursuing a means to evoke the qualities of infrastructural space while conveying a historical narrative, the exhibition’s termination in the present is designed to provoke in the visitor, a perceptual extension of the matrix to engage with the future.

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Dissertação mest., Gestão da Água e da Costa, Universidade do Algarve, 2007

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Regions of Restricted Exchange (RREs) are an important feature of the European coastline. They are historically preferred sites for human settlement and aquaculture and their ecosystems, and consequent human use, may be at risk from eutrophication. The OAERRE project (EVK3-CT1999-0002 concerns ‘Oceanographic Applications to Eutrophication in Regions of Restricted Exchange’. It began in July 2000, and studies six sites. Four of these sites are fjords: Kongsfjorden (west coast of Spitzbergen); Gullmaren (Skagerrak coast of Sweden); Himmerfj.arden (Baltic coast of Sweden); and the Firth of Clyde (west coast of Scotland). Two are bays sheltered by sand bars: Golfe de Fos (French Mediterranean); and Ria Formosa (Portuguese Algarve). Together they exemplify a range of hydrographic and enrichment conditions. The project aims to understand the physical, biogeochemical and biological processes, and their interactions, that determine the trophic status of these coastal marine RRE through the development of simple screening models to define, predict and assess eutrophication. This paper introduces the sites and describes the component parts of a basic screening model and its application to each site using historical data. The model forms the starting point for the OAERRE project and views an RRE as a well-mixed box, exchanging with the sea at a daily rate E determined by physical processes, and converting nutrient to phytoplankton chlorophyll at a fixed yield q: It thus uses nutrient levels to estimate maximum biomass; these preliminary results are discussed in relation to objective criteria used to assess trophic status. The influence of factors such as grazing and vertical mixing on key parameters in the screening model are further studied using simulations of a complex‘research’ model for the Firth of Clyde. The future development of screening models in general and within OAERRE in particular is discussed. In addition, the paper looks ahead with a broad discussion of progress in the scientific understanding of eutrophication and the legal and socioeconomic issues that need to be taken into account in managing the trophic status of RREs.

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Trabalho de Projeto de Natureza Científica para obtenção do grau de Mestre em Engenharia Civil

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Trabalho de Projecto para obtenção do grau de Mestre em Engenharia Civil