991 resultados para 7038-203
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The present study was designed to examine the following: (1) the taxonomic. spatial, and temporal patterns of availability of all invertebrate species associated with Macrocystis (excluding protozoans and nematodes); (2) the utilization of this invertebrate assemblage as food by kelp forest fishes within the Macrocystis "foliage- searching" feeding guild, as well as proximal mechanisms leading to observed patterns of resource partitioning; and (3) the dynamic relationship between availability and utilization of this food resource. The approach was largely descriptive. with observations collected during a 19-month period from June 1975 to December 1976. Chapter I is an investigation of the resource utilization patterns of four species of kelp forest fishes with respect to food-related resource dimensions. and tests aspects of current theory involving inter- and intraspecific competition. Chapter II is a detailed examination of the invertebrate assemblage associated with Macrocystis and presents life histories of the fishes examined during this study. (PDFs contains 387 pages, chapter 1 is 203 pages, chapter 2 is 184 pages)
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One of the objectives of the Terrestrial Initiative in Global Environmental Research is to assess the sensitivity of British plant and animal species to climate change. The first phase of the program involved the identification of criteria for selecting species suitable for the study of effects of projected climate change in the British Isles. Apart from shallow ponds, annual temperature ranges of 0 to 25 C in temperate freshwater habitats are narrower than those in most temperate terrestrial habitats. Although freshwater organisms have to exist within a narrower range than their terrestrial equivalents, few species can survive throughout their life cycle over the whole temperature range. Field studies on the effects of natural and artificial thermal discharges into streams and rivers have shown that increases in water temperature affect aquatic insects at both the species and community level. Although field data provide valuable information, a more productive approach is to determine experimentally the requirements of different species. Although there are just over 1850 species of aquatic insects in the British Isles, detailed quantitative information on the relationship between temperature and development of eggs, larvae and pupa is available for relatively few species. One exception is the egg stage of stoneflies (Plecoptera). The range for egg hatching in stoneflies clearly show that some species could be threatened while others could benefit from a defined increase in water temperature as a result of climate change. A critical review of the available data on this group would produce a set of equations that could be used to predict the ecological effects of climate change on this group of indicator species.
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Capítulo 8 del libro: Guisasola, Jenaro ; Garmendia, Mikel (eds.) "Aprendizaje basado en problemas, proyectos y casos: diseño e implementación de experiencias en la universidad" (ISBN: 978-84-9860-959-2)
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203 p.
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Community Based Resource Management (CBRM) understood as an approach emphasizes a community's capability, responsibility and accountability with regards to managing resources. Based on the recommendations for the Nigerian-German Kainji Lake Fisheries Promotion Project (KLFPP), the Niger and Kebbi States Fisheries Edicts were promulgated in 1997. These edicts, among other things, banned the use of beach seines. Given the conviction of KLFPP, that if communities whose livelihood is linked to the fishery, understand and identify the problems and by consensus agree to the solutions of fisheries problems, they are more likely to adhere to any control measures, specifically the ban on beach seine. In 1999 a first agreement was reached between beach seiners, non-beach seiners and government authorities leading to an almost complete elimination of beach seine on the Lake Kainji. However, despite on going efforts of the Kainji Lake Fisheries Management and Conservation Unit in 2000 and possibly because of certain oversights during and after the first agreement, in May 2001 a significant number of beach seiners was observed. This led to a re-assessment of our approach, which lately culminated into another round of negotiation. The paper presents the latest results on this on-going process
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The paper provides a description of a methodology used for quantitative assessment of post harvest losses in the Kainji Lake Fishery (Nigeria). The sample population was made up of 314 fisherfolk, 115 processors, 125 fish buyers and 111 fish sellers. For the determination of handling losses, 24,839 fishes weighing 2,389.31 kg belonging to 43 species were examined of which 10% by number and 9% by weight deteriorated at checking and 4% by number and 3% by weight at landing. Processing losses recorded 22% by number and 16% by weight deteriorated prior to and during smoking with the traditional 'Banda' kiln. During marketing, 16% of fish sold had deteriorated and 6% by weight of fish bought also deteriorated, mainly due to insect infestation during storage. Based on the 1995 yield estimate for Kainji Lake fishery, approximately 1000 tons of fish estimated at 80 million Naira were lost during handling alone. This figure would be much higher if the level of losses during processing and marketing are included. This assessment technique is recommended for use in obtaining quantifiable data on post harvest losses from other water bodies in Nigeria
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Hybrids of Clariid catfishes; C. gariepinus (Netherlands), C. anguillaris, H. bidorsalis and their parental species were monitored for 8 weeks in 2 x 2 x 1m outdoor concrete tanks. The fry were fed NIFFR diet (40% crude protein) twice daily, 7 days of the week. Growth and survival records were taken weekly. The male HEB X female CLG hybrid showed an overall highest performance in growth rate while the lowest was recorded in male CLA X female CLG hybrid. The male HEB X female CLG hybrid grew at a faster rate than its reciprocal hybrid. In view or their growth rate, it is possible that the growth and survival rates or H. bidorsalis especially at the fry to fingerling stage could be improved through hybridization. The hybrid have potential as commercial food fish
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Bei der Erweiterung der Europäischen Union nach Osten spielen nicht nur politische sondern auch wirtschaftliche Faktoren eine große Rolle. Die Europäische Kommission hat die Agenda 2000 aufgestellt, in der finanz- und wirtschaftspolitische Rahmenbedingungen der Europäischen Union für den Beitritt der zehn mittel- und osteuropäischen Länder (MOEL) dargelegt werden. Die allgemeine Wirtschaftssituation der jetzigen Union sowie der MOEL wurde anhand der Bruttoinlandsprodukte und der Bevölkerungsveränderung im vorigen Heft 3 der Informationen für die Fischwirtschaft dargestellt. Im Folgenden wird die Lage der Fischwirtschaft der einzelnen MOEL und ihre Bewertung aus Sicht der EU-Kommission - wie sie im Bulletin der Europäischen Union dargestellt ist - wiedergegeben. Außerdem werden für jedes Land die Beitrittsperspektiven, d.h. die notwendigen Anpassungsmaßnahmen und auch daraus entstehenden Schwierigkeiten aufgezeigt. Die zu jedem Land dargestellten Graphiken fußen unabhängig von der Darstellung der EU-Kommission auf Daten der FAO.
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In this work, the thermally induced cracking behavior of a segmented coating has been investigated. The geometry under consideration is a hollow cylinder with a segmented coating deposited onto its outer surface. The segmentation cracks are modeled as a periodic array of axial edge cracks. The finite element method is utilized to obtain the solution of the multiple crack problem and the Thermal Stress Intensity Factors (TSIFs) are calculated. Based on dimensional analysis, the main parameters affecting TSIFs are identified. It has been found that the TSIF is a monotonically increasing function of segmentation crack spacing. This result confirms that a segmented coating exhibits much higher thermal shock resistance than an intact counterpart, if only the segmentation crack spacing is narrow enough. The dependence of TSIF on some other parameters, such as normalized time, segmentation crack depth, convection severity as well as material constants, has also been discussed. (C) 2008 Elsevier B.V. All rights reserved.
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DNA is nature’s blueprint, holding within it the genetic code that defines the structure and function of an organism. A complex network of DNA-binding proteins called transcription factors can largely control the flow of information from DNA, so modulating the function of transcription factors is a promising approach for treating many diseases. Pyrrole-imidazole (Py-Im) polyamides are a class of DNA-binding oligomers, which can be synthetically programmed to bind a target sequence of DNA. Due to their unique shape complementarity and a series of favorable hydrogen bonding interactions that occur upon DNA-binding, Py-Im polyamides can bind to the minor groove of DNA with affinities comparable to transcription factors. Previous studies have demonstrated that these cell-permeable small molecules can enter cell nuclei and disrupt the transcription factor-DNA interface, thereby repressing transcription. As the use of Py-Im polyamides has significant potential as a type of modular therapeutic platform, the need for polyamides with extremely favorable biological properties and high potency will be essential. Described herein, a variety of studies have been performed aimed at improving the biological activity of Py-Im polyamides. To improve the biological potency and cellular uptake of these compounds, we have developed a next-generation class of polyamides bearing aryl-turn moieties, a simple structural modification that allows significant improvements in cellular uptake. This strategy was also applied to a panel of high-affinity cyclic Py-Im polyamides, again demonstrating the remarkable effect minor structural changes can have on biological activity. The solubility properties of Py-Im polyamides and use of formulating reagents with their treatment have also been examined. Finally, we describe the study of Py-Im polyamides as a potential artificial transcription factor.