998 resultados para stock identification
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The Argentine hake, Merluccius hubbsi, a demersal-pelagic species found from Rio de Janeiro, Brazil to the Tierra del Fuego, Argentina, has become an important target of the Brazilian bottom-trawler fleet since 2001. Earlier studies focusing on the species have suggested that more than one stock might occur off the Brazilian coast, in accordance with environmental features. In order to evaluate this hypothesis, fish were collected from four different areas in the Brazilian waters in which the hake is distributed, during the summers and winters of 1996-2001 and 2004, the females being used to analyze and compare spatial-temporal variations in ovarian maturation. Gonad indexes were also applied for the same purpose. Results indicate a north-south spawning gradient occurring as from summer at around 21°S to winter near 34°S, leading to the identification of two distinct stocks: one located between 21°S and 29°S (Southeastern stock) and the other between 29°S and 34°S (Southern stock), this latter shared with Uruguay and Argentina. Brazilian stocks present clear signs of overexploitation, the situation calling for an urgent solution.
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Location or stock-specific landing data are necessary to improve management of shark stocks, especially those imperiled by overexploitation as a result of the international shark fin trade. In the current absence of catch monitoring directly at extraction sites, genetic stock identification of fins collected from major market supply chain endpoints offers an overlooked but potentially useful approach for tracing the fins back to their geographical, or stock of, origin. To demonstrate the feasibility of this approach, we used mitochondrial control region (mtCR) sequences to trace the broad geographical origin of 62 Hong Kong market-derived Sphyrna lewini fins. Of these fins 21% were derived from the western Atlantic, where this species is listed as 'Endangered' by the International Union for the Conservation of Nature (IUCN). We also show that S. lewini mtCR sequences are geographically segregated in the western Atlantic (overall ΦST = 0.74, n = 177 sharks), indicating that breeding females either remain close to, or home back to, their natal region for parturition. Mixed stock analysis simulations showed that it is possible to estimate the relative contributions of these mitochondrial stocks to fin mixtures in globally sourced trade hubs. These findings underscore the feasibility of using genetic stock identification to source market-derived shark fins to obtain essential and otherwise unavailable data on exploitation levels, and thus to productively inform stock assessment and management of S. lewini and potentially also of other fished shark species. © Inter-Research 2009.
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Thirty-four microsatellite loci were isolated from three reef fish species; golden snapper Lutjanus johnii, blackspotted croaker Protonibea diacanthus and grass emperor Lethrinus laticaudis using a next generation sequencing approach. Both IonTorrent single reads and Illumina MiSeq paired-end reads were used, with the latter demonstrating a higher quality of reads than the IonTorrent. From the 1–1.5 million raw reads per species, we successfully obtained 10–13 polymorphic loci for each species, which satisfied stringent design criteria. We developed multiplex panels for the amplification of the golden snapper and the blackspotted croaker loci, as well as post-amplification pooling panels for the grass emperor loci. The microsatellites characterized in this work were tested across three locations of northern Australia. The microsatellites we developed can detect population differentiation across northern Australia and may be used for genetic structure studies and stock identification.
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The Stock Identification Methods Working Group (SIMWG) worked by correspondence in 2016. The working group was chaired by Lisa Kerr (USA). The work plan for SIMWG in 2016 comprised four Terms of Reference (ToR), some of which are continuing goals for SIMWG: a ) Review recent advances in stock identification methods; b ) Build a reference database with updated information on known biological stocks for species of ICES interest; c ) Provide technical reviews and expert opinions on matters of stock identifica-tion, as requested by specific Working Groups and SCICOM; d ) Review and report on advances in mixed stock analysis, and assess their po-tential role in improving precision of stock assessment. ToR a) is an ongoing task of SIMWG in which we provide a comprehensive update on recent applications of stock identification techniques to ICES species of interest, summa-rize new approaches in stock identification, and novel combinations of existing applica-tions. ToR b) is a multi-annual ToR in which SIMWG has taking steps to build a reference data-base consisting of SIMWG reviews of issues of stock identity for ICES species. ToR c) is a key ongoing task by SIMWG in which we addresses specific requests by ICES working groups for technical advice on issues of stock identity. This year we provided advice on mackerel in the Northeast Atlantic as requested by WGWIDE. ToR d) is a multi-annual ToR that is focused on tracking developments in the application of mixed stock analysis and the integration of this information into assessment and management.
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The otoliths and lenses of the temperate damselfish Parma microlepis (Gunther) (Pomacentridae) showed similar differences in trace-metal profile for selected locations along the coast of New South Wales, Australia. Otoliths and lenses displayed a differential ability to accumulate metals. Metal concentrations were ranked differently in the two structures (e.g. Sr > Ba > Pb > Rb > Hg in otoliths, and Hg > Sr similar or equal to Rb > Pb > Ba in lenses), and where similar metals were accumulated, they were accumulated at vastly different concentrations (e.g. Ba concentrations in otoliths are a thousand-fold greater than in lenses). Analyses of the otoliths and lenses of P. microlepis from locations close to Sydney and up to 100 kill from the city were able to distinguish amongst these locations with respect to a number of metals, namely Ba, Mn and Hg. Multivariate analyses of otolith and lens data gave similar results among locations (agreement was obtained for Ii out of 15 pair-wise comparisons), and differences were attributable to the differential ability of the two structures to accumulate metals such as Mn and Hg. Trace-metal differences between locations were found to coincide with the proximity of sewage (including industrial waste) and petroleum storage facilities to the different locations.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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We investigated the presence of Candida dubliniensis among isolates previously identified as Candida albicans and maintained in a yeast stock collection from 1994 to 2000. All isolates were serotyped and further evaluated for antifungal susceptibility profile. After doing a screening test for C. dubliniensis isolates based on the capability of colonies to grow at 42°C, its final identification was obtained by randomly amplified polymorphic DNA (RAPD) analysis using three different primers. A total of 46 out of 548 screened isolates did not exhibit growth at 42°C and were further genotyped by RAPD. Eleven isolates were identified as C. dubliniensis with RAPD analysis. Regarding serotypes, 81.5% of C. albicans and all C. dubliniensis isolates belonged to serotype A. Of note, 9 out of 11 C. dubliniensis isolates were obtained from patients with acquired immunodeficiency syndrome (Aids) and all of them were susceptible to azoles and amphotericin B. We found 17 (3%) C. albicans isolates that were dose-dependent susceptibility or resistant to azoles. In conclusion, we found a low rate of C. dubliniensis isolates among stock cultures of yeasts previously identified as C. albicans. Most of these isolates were recovered from oral samples of Aids patients and exhibited high susceptibility to amphotericin B and azoles. C. albicans serotype A susceptible to all antifungal drugs is the major phenotype found in our stock culture.
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This thesis is settled within the STOCKMAPPING project, which represents one of the studies that were developed in the framework of RITMARE Flagship project. The main goals of STOCKMAPPING were the creation of a genomic mapping for stocks of demersal target species and the assembling of a database of population genomic, in order to identify stocks and stocks boundaries. The thesis focuses on three main objectives representing the core for the initial assessment of the methodologies and structure that would be applied to the entire STOCKMAPPING project: individuation of an analytical design to identify and locate stocks and stocks boundaries of Mullus barbatus, application of a multidisciplinary approach to validate biological methods and an initial assessment and improvement for the genotyping by sequencing technique utilized (2b-RAD). The first step is the individuation of an analytical design that has to take in to account the biological characteristics of red mullet and being representative for STOCKMAPPING commitments. In this framework a reduction and selection steps was needed due to budget reduction. Sampling areas were ranked according the individuation of four priorities. To guarantee a multidisciplinary approach the biological data associated to the collected samples were used to investigate differences between sampling areas and GSAs. Genomic techniques were applied to red mullet for the first time so an initial assessment of molecular protocols for DNA extraction and 2b-RAD processing were needed. At the end 192 good quality DNAs have been extracted and eight samples have been processed with 2b-RAD. Utilizing the software Stacks for sequences analyses a great number of SNPs markers among the eight samples have been identified. Several tests have been performed changing the main parameter of the Stacks pipeline in order to identify the most explicative and functional sets of parameters.
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Investigating stock identity of marine species in a multidisciplinary holistic approach can reveal patterns of complex spatial population structure and signatures of potential local adaptation. The population structure of common sole (Solea solea) in the Mediterranean Sea was delineated using genomic and otolith data, including single nucleotide polymorphisms (SNPs) markers and otolith data. SNPs were correlated with environmental and spatial variables to evaluate the impact of these features on the actual genetic population structure. Integrated holistic approach was applied to combine the tracers with different spatio-temporal scales. SNPs data was also used to illustrate the population structure of European hake (Merluccius merluccius) within the Alboran Sea, extending into the neighboring Mediterranean Sea and Atlantic Ocean. The aim was to identify patterns of neutral and potential adaptive genetic variation by applying seascape genomic framework. Results from both genetic and otolith data suggested significant divergence among putative populations of common sole, confirming a clear separation between Western, Adriatic Sea and Eastern Mediterranean Sea. Evidence of fine-scale population structure in the Western Mediterranean Sea was observed at outlier loci level and in the Adriatic. Our study not only indicates that separation among Mediterranean sole population is led primarily by neutral processes, but it also suggests the presence of local adaptation influenced by environmental and spatial factors. The holistic approach by considering the spatio-temporal scales of variation confirmed that the same pattern of separation between these geographical sites is currently occurring and has occurred for many generations. Results showed the occurrence of population structure in Merluccius merluccius by detecting westward–eastward differentiation among populations and distinct subgroups at a fine geographical scale using outlier SNPs. These results enhance the knowledge of the population structure of commercially relevant species to support the application of spatial stock assessment models, including a redefinition of fishery management units.
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There is a widely held paradigm that mangroves are critical for sustaining production in coastal fisheries through their role as important nursery areas for fisheries species. This paradigm frequently forms the basis for important management decisions on habitat conservation and restoration of mangroves and other coastal wetlands. This paper reviews the current status of the paradigm and synthesises the information on the processes underlying these potential links. In the past, the paradigm has been supported by studies identifying correlations between the areal and linear extent of mangroves and fisheries catch. This paper goes beyond the correlative approach to develop a new framework on which future evaluations can be based. First, the review identifies what type of marine animals are using mangroves and at what life stages. These species can be categorised as estuarine residents, marine-estuarine species and marine stragglers. The marine-estuarine category includes many commercial species that use mangrove habitats as nurseries. The second stage is to determine why these species are using mangroves as nurseries. The three main proposals are that mangroves provide a refuge from predators, high levels of nutrients and shelter from physical disturbances. The recognition of the important attributes of mangrove nurseries then allows an evaluation of how changes in mangroves will affect the associated fauna. Surprisingly few studies have addressed this question. Consequently, it is difficult to predict how changes in any of these mangrove attributes would affect the faunal communities within them and, ultimately, influence the fisheries associated with them. From the information available, it seems likely that reductions in mangrove habitat complexity would reduce the biodiversity and abundance of the associated fauna, and these changes have the potential to cause cascading effects at higher trophic levels with possible consequences for fisheries. Finally, there is a discussion of the data that are currently available on mangrove distribution and fisheries catch, the limitations of these data and how best to use the data to understand mangrove-fisheries links and, ultimately, to optimise habitat and fisheries management. Examples are drawn from two relatively data-rich regions, Moreton Bay (Australia) and Western Peninsular Malaysia, to illustrate the data needs and research requirements for investigating the mangrove-fisheries paradigm. Having reliable and accurate data at appropriate spatial and temporal scales is crucial for mangrove-fisheries investigations. Recommendations are made for improvements to data collection methods that would meet these important criteria. This review provides a framework on which to base future investigations of mangrove-fisheries links, based on an understanding of the underlying processes and the need for rigorous data collection. Without this information, the understanding of the relationship between mangroves and fisheries will remain limited. Future investigations of mangrove-fisheries links must take this into account in order to have a good ecological basis and to provide better information and understanding to both fisheries and conservation managers.
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Structural variation is variation in structure of DNA regions affecting DNA sequence length and/or orientation. It generally includes deletions, insertions, copy-number gains, inversions, and transposable elements. Traditionally, the identification of structural variation in genomes has been challenging. However, with the recent advances in high-throughput DNA sequencing and paired-end mapping (PEM) methods, the ability to identify structural variation and their respective association to human diseases has improved considerably. In this review, we describe our current knowledge of structural variation in the mouse, one of the prime model systems for studying human diseases and mammalian biology. We further present the evolutionary implications of structural variation on transposable elements. We conclude with future directions on the study of structural variation in mouse genomes that will increase our understanding of molecular architecture and functional consequences of structural variation.
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Adult-type rhabdomyosarcoma (RMS) has been classically defined as a pleomorphic sarcoma with desmin expression occurring in adult patients. To reevaluate this entity, we analyzed a series of 57 cases using immunohistochemistry for desmin, myogenin, alpha smooth muscle actin, h-caldesmon, pankeratin AE1/AE3, epithelial membrane antigen (EMA), S100 protein, CD34, MDM2, and CDK4. In this series, there were 36 men and 21 women aged from 22 to 87 years (median: 59). Tumors were mainly located in the lower limbs (27 cases), trunk wall (15 cases), and upper limbs (10 cases). Most tumors were deeply located (51/54) with a size from 1 to 30 cm (median: 8 cm). Cases were classified in 3 histologic categories: spindle cell RMS (25 cases), pleomorphic RMS (16 cases), and mixed type (16 cases). Forty-one tumors were grade 3 and 16 grade 2. Immunohistochemistry showed that every case was positive for desmin and myogenin. Alpha smooth muscle actin was positive in 21%, pankeratin AE1/AE3 in 20%, and CD34 in 13.2%. Treatment modalities and follow-up were available in 46 cases. Median follow-up was 60.9 months. Eight patients developed a local recurrence and 16 a distant metastasis with a 5-year overall survival rate of 52.6% and a 5-year metastasis-free survival of 62.9%. The only predictive factor for metastasis was histologic grade. In conclusion, adult-type RMS is a rare sarcoma occurring mainly in the extremities and trunk wall with 2 main histologic patterns, spindle cell, and pleomorphic patterns, which represent the end of the spectrum of a single entity.
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In this paper we deal with the identification of dependencies between time series of equity returns. Marginal distribution functions are assumed to be known, and a bivariate chi-square test of fit is applied in a fully parametric copula approach. Several families of copulas are fitted and compared with Spanish stock market data. The results show that the t-copula generally outperforms other dependence structures, and highlight the difficulty in adjusting a significant number of bivariate data series