31 resultados para Rapid-Prototyping-Verfahren
Resumo:
This report documents the methods used at the Monterey Bay Aquarium Research Institute (MBARI) for analyzing seawater nutrient samples with an Alpkem Series 300 Rapid Flow Analyzer (RFA) system. The methods have been optimized for the particular requirements of this laboratory. The RFA system has been used to analyze approximately 20,000 samples during the past two years. The methods have been optimized to run nutrient analyses in a routine manner with a detection limit of better than -±1% and a within run precision of -±1% of the full scale concentration range. The normal concentration ranges are 0-200 ~M silicate, 0-5 ~M phosphate, 0-50 ~M nitrate, 0-3 ~M nitrite, and 0-10 ~M ammonium. The memorandum is designed to be used in a loose-leaf binder format. Each page is dated and as revisions are made, they should be inserted into the binder. The revisions should be added into the binder. Retain the old versions in order to maintain a historical record of the procedures. (88 pages)
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As more people discover coastal and marine protected areas as destinations for leisure-time pursuits, the task of managing coastal resources while providing opportunities for high quality visitor experiences becomes more challenging. Many human impacts occur at these sites; some are caused by recreation and leisure activities on-site, and others by activities such as agriculture, aquaculture, or residential and economic development in surrounding areas. Coastal management professionals are continually looking for effective ways to prevent or mitigate negative impacts of visitor use. (PDF contains 8 pages) Most coastal and marine protected area managers are challenged with balancing two competing goals—protection of natural and cultural resources and provision of opportunities for public use. In most cases, some level of compromise between the goals is necessary, where one goal constrains or “outweighs” the other. Often there is a lack of clear agreement about the priority of these competing goals. Consequently, while natural resource decisions should ultimately be science-based and objective, such decisions are frequently made under uncertainty, relying heavily upon professional judgment. These decisions are subject to a complex array of formal and informal drivers and constraints—data availability, timing, legal mandate, political will, diverse public opinion, and physical, human, and social capital. This paper highlights assessment, monitoring, and planning approaches useful to gauge existing resource and social conditions, determine feasibility of management actions, and record decision process steps to enhance defensibility. Examples are presented from pilot efforts conducted at the Rookery Bay National Estuarine Research Reserve (NERR) and Ten Thousand Islands National Wildlife Refuge (NWR) in South Florida.
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The Flower Garden Banks are topographic features on the edge of the continental shelf in the northwest Gulf of Mexico. These banks are approximately 175 km southeast of Galveston, Texas at 28° north latitude and support the northernmost coral reefs on the North American continental shelf. The East and West Flower Garden Banks (EFG and WFG) and Stetson Bank, a smaller sandstone bank approximately 110 km offshore, are managed and protected as the Flower Garden Banks National Marine Sanctuary (FGBNMS). As part of a region-wide initiative to assess coral reef condition, the benthic and fish communities of the EFG and WFG were assessed using the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol. The AGRRA survey was conducted during a week-long cruise in August 1999 that was jointly sponsored by the FGBNMS and the Reef Environmental Education Foundation (REEF). A total of 25 coral transects, 132 algal quadrats, 24 fish transects, and 26 Roving Diver (REEF) surveys were conducted. These surveys revealed reefs with high coral cover, dominated by large, healthy corals, little macroalgae, and healthy fish populations. The percent live coral cover was 53.9 and 48.8 at the WFG and EFG, respectively, and the average colony diameter was 93 and 81 cm. Fish diversity was lower than most Caribbean reefs, but large abundances and size of many species reflected the low fishing pressure on the banks. The benthic and fish assemblages at the EFG and WFG were similar. Due to its near pristine conditions, the FGB data will prove to be a valuable component in the AGRRA database and its resulting scale of reef condition for the region. (PDF contains 22 pages.)
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A rapid and cost effective DNA test is described to identify European eel (Anguilla anguilla) and North American eel (Anguilla rostrata). By means of polymerase chain reaction (PCR) technique parts of the mitochondrial cytochrome b gene are amplified with species specific primers which are designed to produce PCR fragments of different characteristic sizes for European and American eel. The size differences can easily be made visible by agarose gel electrophoresis
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The discrimination of stocks and separate reproductive units within fish species to facilitate fisheries management based on biological data has always been a challenge to fisheries biologists. We describe the use of three different molecular genetic techniques to detect genetic differences between stocks and closely related species. Direct sequencing of the mitochondrial ND3 gene describes the relationship between different aquaculture strains and natural populations of rainbow trout and revealed genetic homogeneity within the hatchery strains. Microsatellite analyses were used to explore the differences between redfish species from the genus Sebastes and to verify populations structure within S. mentella and S. marinus. This lead to an un equivocal discrimination of the species and an indication of populations structure within those species in the North Atlantic. The Amplified Fragment Length Polymorphisum (AFLP) methodology revealed genetic differences between Baltic and North Sea dap (Limanda limanda)and a possible population structure within the North Sea.
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The content of free formaldehyde (FA) in minced fish muscle was measured by the following procedure: A mixture of minced fish muscle and water was deproteinized by means of the Carrez reagent. The FA content of the filtrate was determined reflectometrically using the Reflectoquant test strips and the RQflex. The results agreed well with the colorimetrically (Nash test) measured FA content. Der Gehalt an freiem Formaldehyd (FA)in Fischerzeugnissen wurde mit folgender Methode bestimmt: Zerkleinertes Fischfleisch wurde mit Wasser homogenisiert und mit Carrez-Reagenz enteiweißt. Der Formaldehydgehalt des Filtrates wurde reflektometrisch unter Verwendung von Reflectoquant-Teststätbchen und des RQflex ermittelt. Die Ergebnisse stimmten gut mit kolorimetrisch (Nash Test) gemessenen FA-Gehalten überein.
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Over much of Britain, 1995 and 1996 have been perceived as drought years. To evaluate the impact that local climatic conditions are having upon successional changes in higher vegetation (macrophytes), Speakmans Pond in Epping Forest was surveyed and mapped in 1996. The results are related to previous vegetation surveys carried out in 1989 and 1991. In 1989 the dominant marginal vegetation was floating sweet-grass Glyceria fluitans, which also covered a major part of the main body of the pond. Other abundant species included soft rush Juncus effusus, reed mace Typha latifolia and yellow flag Iris pseudocorus. A small (central) area of open water contained bladderwort Utricularia vulgaris and white water-lily Nymphaea alba. A similar plant coverage was found in 1991, with a dominance of floating sweet-grass along the shallow eastern edge. A marked change in the pond was found during the 1996 survey of vegetation in July, when the pool was dry. The major plant cover now consisted of creeping bent Agrostis stolonifera, with isolated clumps of Yorkshire fog Holcus lanatus around the edges; both are terrestrial grasses found on land surrounding the pond. Rushes (Juncus) had increased their distribution round the margins of the pond, and the patch of yellow flag noted in 1989 and 1991 was not found in 1996. The deeper trenches were also dry, but a small patch of white water-lily remained adjacent to one of the trenches.
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This note describes changes to the relative extent of four structurally dominant submerged macrophytes in a pond on Holy Island National Nature Reserve, Northumbria, between 1991 and 1998. The estimated extent of the four submerged macrophytes and bare substratum between 1991 and 1998 showed dramatic changes with no obvious pattern or periodicity, as well as no identifiable natural or anthropogenic causes. Chaotic variation may be an important character of submerged pond plant populations, so that surveys taken in a single year may give an unreliable picture of plant populations.
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Referat gehalten auf der WEFTA-Tagung in Hamburg
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Demersal fishes hauled up from depth experience rapid decompression. In physoclists, this can cause overexpansion of the swim bladder and resultant injuries to multiple organs (barotrauma), including severe exophthalmia (“pop-eye”). Before release, fishes can also be subjected to asphyxia and exposure to direct sunlight. Little is known, however, about possible sensory deficits resulting from the events accompanying capture. To address this issue, electroretinography was used to measure the changes in retinal light sensitivity, flicker fusion frequency, and spectral sensitivity in black rockfish (Sebastes melanops) subjected to rapid decompression (from 4 atmospheres absolute [ATA] to 1 ATA) and Pacific halibut (Hippoglossus stenolepis) exposed to 15 minutes of simulated sunlight. Rapid decompression had no measurable influence on retinal function in black rockfish. In contrast, exposure to bright light significantly reduced retinal light sensitivity of Pacific halibut, predominately by affecting the photopigment which absorbs the green wavelengths of light (≈520–580 nm) most strongly. This detriment is likely to have severe consequences for postrelease foraging success in green-wavelength-dominated coastal waters. The visual system of Pacific halibut has characteristics typical of species adapted to low light environments, and these characteristics may underlie their vulnerability to injury from exposure to bright light.