936 resultados para alphabet, collection, reorganization
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The structural annotation of proteins with no detectable homologs of known 3D structure identified using sequence-search methods is a major challenge today. We propose an original method that computes the conditional probabilities for the amino-acid sequence of a protein to fit to known protein 3D structures using a structural alphabet, known as Protein Blocks (PBs). PBs constitute a library of 16 local structural prototypes that approximate every part of protein backbone structures. It is used to encode 3D protein structures into 1D PB sequences and to capture sequence to structure relationships. Our method relies on amino acid occurrence matrices, one for each PB, to score global and local threading of query amino acid sequences to protein folds encoded into PB sequences. It does not use any information from residue contacts or sequence-search methods or explicit incorporation of hydrophobic effect. The performance of the method was assessed with independent test datasets derived from SCOP 1.75A. With a Z-score cutoff that achieved 95% specificity (i.e., less than 5% false positives), global and local threading showed sensitivity of 64.1% and 34.2%, respectively. We further tested its performance on 57 difficult CASP10 targets that had no known homologs in PDB: 38 compatible templates were identified by our approach and 66% of these hits yielded correctly predicted structures. This method scales-up well and offers promising perspectives for structural annotations at genomic level. It has been implemented in the form of a web-server that is freely available at http://www.bo-protscience.fr/forsa.
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In this paper, sensing coverage by wireless camera-embedded sensor networks (WCSNs), a class of directional sensors is studied. The proposed work facilitates the autonomous tuning of orientation parameters and displacement of camera-sensor nodes in the bounded field of interest (FoI), where the network coverage in terms of every point in the FoI is important. The proposed work is first of its kind to study the problem of maximizing coverage of randomly deployed mobile WCSNs which exploits their mobility. We propose an algorithm uncovered region exploration algorithm (UREA-CS) that can be executed in centralized and distributed modes. Further, the work is extended for two special scenarios: 1) to suit autonomous combing operations after initial random WCSN deployments and 2) to improve the network coverage with occlusions in the FoI. The extensive simulation results show that the performance of UREA-CS is consistent, robust, and versatile to achieve maximum coverage, both in centralized and distributed modes. The centralized and distributed modes are further analyzed with respect to the computational and communicational overheads.
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In this paper, we consider the problem of power allocation in MIMO wiretap channel for secrecy in the presence of multiple eavesdroppers. Perfect knowledge of the destination channel state information (CSI) and only the statistical knowledge of the eavesdroppers CSI are assumed. We first consider the MIMO wiretap channel with Gaussian input. Using Jensen's inequality, we transform the secrecy rate max-min optimization problem to a single maximization problem. We use generalized singular value decomposition and transform the problem to a concave maximization problem which maximizes the sum secrecy rate of scalar wiretap channels subject to linear constraints on the transmit covariance matrix. We then consider the MIMO wiretap channel with finite-alphabet input. We show that the transmit covariance matrix obtained for the case of Gaussian input, when used in the MIMO wiretap channel with finite-alphabet input, can lead to zero secrecy rate at high transmit powers. We then propose a power allocation scheme with an additional power constraint which alleviates this secrecy rate loss problem, and gives non-zero secrecy rates at high transmit powers.
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The goal of this project was to gather information on wetland restoration projects in the Moro Bay, California, region. Data provided to the San Francisco Estuary Institute (SFEI) will be used to enhance a web-based, public access database, the Bay Area Wetland Project Tracker. Wetland Tracker provides information on the location, size, sponsors, habitats, contact persons, and status of included projects. Its website provides an interactive map of planned and completed wetland projects (http://www.wetlandtracker.org). (Document contains 4 pages)
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(4pp.)
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Aboriginal peoples in Canada have been mapping aspects of their cultures for more than a generation. Indians, Inuit, Métis, non-status Indians and others have called their maps by different names at various times and places: land use and occupancy; land occupancy and use; traditional use; traditional land use and occupancy; current use; cultural sensitive areas; and so on. I use “land use and occupancy mapping” in a generic sense to include all the above. The term refers to the collection of interview data about traditional use of resources and occupancy of lands by First Nation persons, and the presentation of those data in map form. Think of it as the geography of oral tradition, or as the mapping of cultural and resource geography. (PDF contains 81 pages.)
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Data have been collected on fisheries catch and effort trends since the latter half of the 1800s. With current trends in declining stocks and stricter management regimes, data need to be collected and analyzed over shorter periods and at finer spatial resolution than in the past. New methods of electronic reporting may reduce the lag time in data collection and provide more accurate spatial resolution. In this study I evaluated the differences between fish dealer and vessel reporting systems for federal fisheries in the US New England and Mid-Atlantic areas. Using data on landing date, report date, gear used, port landed, number of hauls, number of fish sampled and species quotas from available catch and effort records I compared dealer and vessel electronically collected data against paper collected dealer and vessel data to determine if electronically collected data are timelier and more accurate. To determine if vessel or dealer electronic reporting is more useful for management, I determined differences in timeliness and accuracy between vessel and dealer electronic reports. I also compared the cost and efficiency of these new methods with less technology intensive reporting methods using available cost data and surveys of seafood dealers for cost information. Using this information I identified potentially unnecessary duplication of effort and identified applications in ecosystem-based fisheries management. This information can be used to guide the decisions of fisheries managers in the United States and other countries that are attempting to identify appropriate fisheries reporting methods for the management regimes under consideration. (PDF contains 370 pages)
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To be in compliance with the Endangered Species Act and the Marine Mammal Protection Act, the United States Department of the Navy is required to assess the potential environmental impacts of conducting at-sea training operations on sea turtles and marine mammals. Limited recent and area-specific density data of sea turtles and dolphins exist for many of the Navy’s operations areas (OPAREAs), including the Marine Corps Air Station (MCAS) Cherry Point OPAREA, which encompasses portions of Core and Pamlico Sounds, North Carolina. Aerial surveys were conducted to document the seasonal distribution and estimated density of sea turtles and dolphins within Core Sound and portions of Pamlico Sound, and coastal waters extending one mile offshore. Sea Surface Temperature (SST) data for each survey were extracted from 1.4 km/pixel resolution Advanced Very High Resolution Radiometer remote images. A total of 92 turtles and 1,625 dolphins were sighted during 41 aerial surveys, conducted from July 2004 to April 2006. In the spring (March – May; 7.9°C to 21.7°C mean SST), the majority of turtles sighted were along the coast, mainly from the northern Core Banks northward to Cape Hatteras. By the summer (June – Aug.; 25.2°C to 30.8°C mean SST), turtles were fairly evenly dispersed along the entire survey range of the coast and Pamlico Sound, with only a few sightings in Core Sound. In the autumn (Sept. – Nov.; 9.6°C to 29.6°C mean SST), the majority of turtles sighted were along the coast and in eastern Pamlico Sound; however, fewer turtles were observed along the coast than in the summer. No turtles were seen during the winter surveys (Dec. – Feb.; 7.6°C to 11.2°C mean SST). The estimated mean surface density of turtles was highest along the coast in the summer of 2005 (0.615 turtles/km², SE = 0.220). In Core and Pamlico Sounds the highest mean surface density occurred during the autumn of 2005 (0.016 turtles/km², SE = 0.009). The mean seasonal abundance estimates were always highest in the coastal region, except in the winter when turtles were not sighted in either region. For Pamlico Sound, surface densities were always greater in the eastern than western section. The range of mean temperatures at which turtles were sighted was 9.68°C to 30.82°C. The majority of turtles sighted were within water ≥ 11°C. Dolphins were observed within estuarine waters and along the coast year-round; however, there were some general seasonal movements. In particular, during the summer sightings decreased along the coast and dolphins were distributed throughout Core and Pamlico Sounds, while in the winter the majority of dolphins were located along the coast and in southeastern Pamlico Sound. Although relative numbers changed seasonally between these areas, the estimated mean surface density of dolphins was highest along the coast in the spring of 2006 (9.564 dolphins/km², SE = 5.571). In Core and Pamlico Sounds the highest mean surface density occurred during the autumn of 2004 (0.192 dolphins/km², SE = 0.066). The estimated mean surface density of dolphins was lowest along the coast in the summer of 2004 (0.461 dolphins/km², SE = 0.294). The estimated mean surface density of dolphins was lowest in Core and Pamlico Sounds in the summer of 2005 (0.024 dolphins/km², SE = 0.011). In Pamlico Sound, estimated surface densities were greater in the eastern section except in the autumn. Dolphins were sighted throughout the entire range of mean SST (7.60°C to 30.82°C), with a tendency towards fewer dolphins sighted as water temperatures increased. Based on the findings of this study, sea turtles are most likely to be encountered within the OPAREAs when SST is ≥ 11°C. Since sea turtle distributions are generally limited by water temperature, knowing the SST of a given area is a useful predictor of sea turtle presence. Since dolphins were observed within estuarine waters year-round and throughout the entire range of mean SST’s, they likely could be encountered in the OPAREAs any time of the year. Although our findings indicated the greatest number of dolphins to be present in the winter and the least in the summer, their movements also may be related to other factors such as the availability of prey. (PDF contains 28 pages)
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Details are given of a programme for fresh fish collection and distribution in Ondo State, Nigeria. Collection centers, organization and managerial structure, collection scheme, trade system, price determination, management and distribution are described
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Catch and effort assessment surveys have been used to assess trends in fish landings in Kenyan waters of Lake Victoria since 1976. Landings reached a maximum of 200000 t annually in 1989-1991 as Nile perch, Lates niloticus (L.), catches increased due to an expansion in stock size and increased fishing effort. CPUE peaked at 180 kg boat day-1 in 1989 and decreased thereafter with increasing effort. By 1998 total Nile perch catches were half those at the beginning of the decade despite increased effort. Catches of Rastrineobola argentea (Pellegrin) have levelled off despite increased effort.