982 resultados para fish sampling


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Pelagic fish (except for tuna) are landed in Sierra Leone mainly by the artisanal fishermen. The two most important species are Sardinella and Ethmalosa.Deep-sea species are normally exploited by purse seiners of foreign countries. The landings of artisanal fishermen largely comprise Sardinella eba.Landing data for Sardinella landed at Tombo and Goderich, and for Ethmalosa at Tombo, are presented in tabular form. Collection methods are described, with a definition of the unit of fishing effort, and a description of the gear used.The landing data are discussed with particular attention to fishing effort, catch per unit effort, and price per ton

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The 25th annual meeting of WEFTA was held in Noordwijkerhout, The Netherlands, in November 1995 as an "International Seafood Conference". In 12 sessions 40 oral presentations and 60 posters were presented. The topics included among others: Quality assurance, consumer demands and behaviour, processing, packaging, distribution, nutrition, storage, analytical methodology. The conference was attended by 210 participants from 33 countries.

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Financial support is going to be applied for from the European Commission in order to establish the European Fish Ageing Network (EFAN). The project, which was planned and initiated from Norway (Floedevigen) is supposed to be a concerted action from 14 European Countries involving about 35 institutions. The primary aim of the network is to coordinate the research in age reading, especially the improvement of data bases for reference material, the transformation of research (e.g. daily ring formation in otoliths) to each interested reader. Moreover, the applied financial support is supposed to be preliminary spent for travel of researcher and technicians to other institutes where the same fish species are aged. Reference material is supposed to be sent to the institutes for check-reading. Specific workshops will be held in cases where heterogeneous results occur from check-reading the reference material.

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From 25 November until 8 Deeember 1994, a sea-going workshop with the above title was carried out on board RV "Walther Herwig IlI" under the umbrella of the Baltie Marine Biologists (BMlJ) and the International Council for the Exploration of the Sea (ICES). Under the co-convenorship of the first two authors of this paper, 11 seientists from 8 of the 9 countries bordering the Baltic Sea (except Sweden) actively involved in research monitoring into fish diseases/parasites participated. The main reason for holding the workshop was that, although fish disease monitoring programmes on the abundance and spatial distribution of fish diseases/parasites are being carried out by some of the countries bordering the Baltic Sea, there is still a striking lack of seientific information as compared to other seas, such as the North Sea. Moreover, since new fish disease monitoring programmes have recently been started (mainly by the new Baltic republics Latvia and Estonia, which recently became ICES-member countries) or are planned for the near future (Lithuania), BMB as weil as ICES felt the need for a interealibration and standardization of methodologies applied during fish disease/parasite surveys for the specific conditions in the Baltic Sea. Therefore, the major objectives of the workshop were -to obtain information about the disease/parasite prevalence in Baltic (Platichthys flesus) and other abundant fish species along a transect from the western (Mecklenhurg Bight) to the eastern (Gulf of Finland) Baltic Sea to be used as a baseline for future studies, -to intercalibrate methodologies applied for sampling, diagnosis of diseases/parasites, reporting and analyses of disease data, -if necessary, to recommend standard methodologies to be used for fish disease/parasite monitoring programmes under the specific conditions in the Baltic Sea. Although the data have yet not been completely analyzed, there is indication for some pronounced spatial trends regarding the prevalence of certain diseases/parasites, mainly for Iymphocystis and skin ulcerations in flounder but also for diseases and parasites of cod (Gadus morhua) which can be seen in figures 2 and 4. Recommendations for standard methodologies will later be published elsewhere.

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DNA in canned tuna is degraded into short fragments of a rew hundred base pairs. The polymerase chain reaction (PCR) was used to amplify short sequences of mitochondrial DNA, which were denatured and analysed by polyacrylamide gel electrophoresis (native PAGE) for detection of single strand conformation polymorphisms. Species specific patterns of DNA bands were obtained for a number of tuna and bonito species. DE: In Thunfischkonserven liegt die DNA in Form kurzkettiger Fragmente von wenigen Hundert Basenpaaren Länge vor. Mit Hilfe der Polymerase-Kettenreaktion (PCR) wurden kurze Sequenzen der mitochondrialen DNA vervielfältigt. Anschließend wurde die gebildete DNA in Einzelsträngen überführt, die durch eine native Polyacrylamidgel-Elektrophorese (PAGE) aufgetrennt wurde. Für eine Reihe von Thunfischen und Boniten ergaben die Einzelstränge artspezifische Bandenmuster, die auf unterschiedliche Konformationen der DNA-Stränge der einzelnen Fischarten zurückzuführen sind.

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Curve samplers are sampling algorithms that proceed by viewing the domain as a vector space over a finite field, and randomly picking a low-degree curve in it as the sample. Curve samplers exhibit a nice property besides the sampling property: the restriction of low-degree polynomials over the domain to the sampled curve is still low-degree. This property is often used in combination with the sampling property and has found many applications, including PCP constructions, local decoding of codes, and algebraic PRG constructions.

The randomness complexity of curve samplers is a crucial parameter for its applications. It is known that (non-explicit) curve samplers using O(log N + log(1/δ)) random bits exist, where N is the domain size and δ is the confidence error. The question of explicitly constructing randomness-efficient curve samplers was first raised in [TU06] where they obtained curve samplers with near-optimal randomness complexity.

In this thesis, we present an explicit construction of low-degree curve samplers with optimal randomness complexity (up to a constant factor) that sample curves of degree (m logq(1/δ))O(1) in Fqm. Our construction is a delicate combination of several components, including extractor machinery, limited independence, iterated sampling, and list-recoverable codes.

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How powerful are Quantum Computers? Despite the prevailing belief that Quantum Computers are more powerful than their classical counterparts, this remains a conjecture backed by little formal evidence. Shor's famous factoring algorithm [Shor97] gives an example of a problem that can be solved efficiently on a quantum computer with no known efficient classical algorithm. Factoring, however, is unlikely to be NP-Hard, meaning that few unexpected formal consequences would arise, should such a classical algorithm be discovered. Could it then be the case that any quantum algorithm can be simulated efficiently classically? Likewise, could it be the case that Quantum Computers can quickly solve problems much harder than factoring? If so, where does this power come from, and what classical computational resources do we need to solve the hardest problems for which there exist efficient quantum algorithms?

We make progress toward understanding these questions through studying the relationship between classical nondeterminism and quantum computing. In particular, is there a problem that can be solved efficiently on a Quantum Computer that cannot be efficiently solved using nondeterminism? In this thesis we address this problem from the perspective of sampling problems. Namely, we give evidence that approximately sampling the Quantum Fourier Transform of an efficiently computable function, while easy quantumly, is hard for any classical machine in the Polynomial Time Hierarchy. In particular, we prove the existence of a class of distributions that can be sampled efficiently by a Quantum Computer, that likely cannot be approximately sampled in randomized polynomial time with an oracle for the Polynomial Time Hierarchy.

Our work complements and generalizes the evidence given in Aaronson and Arkhipov's work [AA2013] where a different distribution with the same computational properties was given. Our result is more general than theirs, but requires a more powerful quantum sampler.

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Tanzania Fisheries Research Institute being currently the only fisheries research institute in Tanzania has sole responsibility of marking the presence and distribution of fish species in the country. This work is expected to be completed by the year 2005. In order that this work can be accomplished, both published works and field observations (including geographical location using GPS) have to be compiled. Since the institute has centers in all the Great Lakes and one along the Indian Ocean coast, it is expected that field observations and identifications will be obtained and incorporated into the document to be produced by 2005. (PDF contains 15 pages)