382 research outputs found

    Preliminary results from the Caribbean Acoustic Tracking Network (CATn): a data sharing partnership for acoustic tracking and movement ecology of marine animals in the Caribbean Sea

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    We have recently exchanged and integrated into a single database tag detections for conch, teleost and elasmobranch fish from four separately maintained arrays in the U.S. Virgin Islands including the NMFS queen conch array (St. John nearshore), NOAA’s Biogeography Branch array (St. John nearshore & midshelf reef); UVI shelf edge arrays (Marine Conservation District, Grammanik & other shelf edge); NOAA NMFS Apex Predator array COASTSPAN (St. John nearshore). The integrated database has over 7.5 million hits. Data is shared only with consent of partners and full acknowledgements. Thus, the summary of integrated data here uses data from NOAA and UVI arrays under a cooperative agreement. The benefits of combining and sharing data have included increasing the total area of detection resulting in an understanding of broader scale connectivity than would have been possible with a single array. Partnering has also been cost-effectiveness through sharing of field work, staff time and equipment and exchanges of knowledge and experience across the network. Use of multiple arrays has also helped in optimizing the design of arrays when additional receivers are deployed. The combined arrays have made the USVI network one of the most extensive acoustic arrays in the world with a total of 150+ receivers available, although not necessarily all deployed at all times. Currently, two UVI graduate student projects are using acoustic array data

    Twin-Photon Confocal Microscopy

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    A recently introduced two-channel confocal microscope with correlated detection promises up to 50% improvement in transverse spatial resolution [Simon, Sergienko, Optics Express {\bf 18}, 9765 (2010)] via the use of photon correlations. Here we achieve similar results in a different manner, introducing a triple-confocal correlated microscope which exploits the correlations present in optical parametric amplifiers. It is based on tight focusing of pump radiation onto a thin sample positioned in front of a nonlinear crystal, followed by coincidence detection of signal and idler photons, each focused onto a pinhole. This approach offers further resolution enhancement in confocal microscopy

    Protein Phylogenetic Analysis of Ca2+/cation Antiporters and Insights into their Evolution in Plants

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    Cation transport is a critical process in all organisms and is essential for mineral nutrition, ion stress tolerance, and signal transduction. Transporters that are members of the Ca2+/cation antiporter (CaCA) superfamily are involved in the transport of Ca2+ and/or other cations using the counter exchange of another ion such as H+ or Na+. The CaCA superfamily has been previously divided into five transporter families: the YRBG, Na+/Ca2+ exchanger (NCX), Na+/Ca2+, K+ exchanger (NCKX), H+/cation exchanger (CAX), and cation/Ca2+ exchanger (CCX) families, which include the well-characterized NCX and CAX transporters. To examine the evolution of CaCA transporters within higher plants and the green plant lineage, CaCA genes were identified from the genomes of sequenced flowering plants, a bryophyte, lycophyte, and freshwater and marine algae, and compared with those from non-plant species. We found evidence of the expansion and increased diversity of flowering plant genes within the CAX and CCX families. Genes related to the NCX family are present in land plant though they encode distinct MHX homologs which probably have an altered transport function. In contrast, the NCX and NCKX genes which are absent in land plants have been retained in many species of algae, especially the marine algae, indicating that these organisms may share “animal-like” characteristics of Ca2+ homeostasis and signaling. A group of genes encoding novel CAX-like proteins containing an EF-hand domain were identified from plants and selected algae but appeared to be lacking in any other species. Lack of functional data for most of the CaCA proteins make it impossible to reliably predict substrate specificity and function for many of the groups or individual proteins. The abundance and diversity of CaCA genes throughout all branches of life indicates the importance of this class of cation transporter, and that many transporters with novel functions are waiting to be discovered

    Diversité fonctionnelle: Nécessité d'évaluer la réponse écologique des assemblages de poissons de récif à une perturbation des stratégies de protection

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    Developing and evaluating process-oriented metrics, such as functional trait diversity metrics, is a high priority to assess the ecological responses of reef fish communities to disturbances and for adaptive ecosystem-based management in marine protected areas (MPAs). We applied five functional diversity metrics (functional entities, redundancy, richness, dispersion, and evenness) to fish assemblage data from an 11-year monitoring dataset of coral reefs in the U.S. Virgin Islands to assess: 1) the spatio-temporal variance in the trophic function of fish communities before, during and after a mass coral bleaching event in 2005; and 2) the association of fish functional diversity with benthic composition, diversity, and structure of reefs inside and outside of No-Take and Multiple Use MPAs. The lack of spatial variation in fish functional diversity metrics suggested no MPA effects during the evaluated time. After the coral bleaching event in 2005, the number of fish functional entities, functional richness, and variation (dispersion) declined inside a No-Take MPA in St. Croix, failing to return to pre-disturbance values over the subsequent seven years. Reefs with high topographic complexity and hard coral species richness supported high richness and redundancy of functional roles. We concluded that functional diversity metrics based on the trophic function of fishes should be considered as tools to monitor ecological functional recovery in MPAs.Fil: Rincón Díaz, Martha Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. State University of Oregon; Estados UnidosFil: Pittman, Simon. University Of Plymouth. School Of Marine Sciences; Reino UnidoFil: Eager, Aaron. University of New South Wales. Faculty of Science. School of Biological-earth and Environmental Sciences; AustraliaFil: Heppell, Selina. State University of Oregon; Estados Unidos73rd Annual Gulf And Caribbean Fisheries Institute Virtual MeetingMarathonEstados UnidosGulf and Caribbean Fisheries Institut

    Linear Optical Quantum Computing in a Single Spatial Mode

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    We present a scheme for linear optical quantum computing using time-bin encoded qubits in a single spatial mode. We show methods for single-qubit operations and heralded controlled phase (CPhase) gates, providing a sufficient set of operations for universal quantum computing with the Knill-Laflamme-Milburn scheme. Our scheme is suited to available photonic devices and ideally allows arbitrary numbers of qubits to be encoded in the same spatial mode, demonstrating the potential for time-frequency modes to dramatically increase the quantum information capacity of fixed spatial resources. As a test of our scheme, we demonstrate the first entirely single spatial mode implementation of a two-qubit quantum gate and show its operation with an average fidelity of 0.84+-0.07.Comment: 5 pages, 4 figures. Updated to be consistent with the published versio

    Status of the coral reef ecosystems in the U.S. Caribbean and Gulf of Mexico: Florida, Flower Garden Banks, Puerto Rico, Navassa and USVI

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    This chapter covers coral reef areas under the jurisdiction of the USA in the Wider Caribbean: Florida; Flower Garden Banks; Puerto Rico; U.S. Virgin Islands; and Navassa. The following information is condensed from six chapters of The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008. Access to the full text of this comprehensive report is available at: http://ccma.nos.noaa.gov/stateofthereefs

    Physiological function and catalytic versatility of bacterial multihaem cytochromescinvolved in nitrogen and sulfur cycling

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    Bacterial MCCs (multihaem cytochromes c) represent widespread respiratory electron-transfer proteins. In addition, some of them convert substrates such as nitrite, hydroxylamine, nitric oxide, hydrazine, sulfite, thiosulfate or hydrogen peroxide. In many cases, only a single function is assigned to a specific MCC in database entries despite the fact that an MCC may accept various substrates, thus making it a multifunctional catalyst that can play diverse physiological roles in bacterial respiration, detoxification and stress defence mechanisms. The present article briefly reviews the structure, function and biogenesis of selected MCCs that catalyse key reactions in the biogeochemical nitrogen and sulfur cycles

    Status of coral reef ecosystems in a marine managed area in St. Croix, USVI [poster]

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    This poster presents information on the status and trends of coral reef ecosystems in St. Croix, US Virgin Islands (USVI). Data were collected by NOAA’s Center for Coastal Monitoring and Assessment Biogeography Branch (CCMA-BB) from 2001-2006 at 1,275 random locations in and around Buck Island Reef National Monument (BIRNM). The main objective was to quantify changes in fish species and assemblage diversity, abundance, biomass and size structure; to provide spatially explicit information on the distribution of key species or groups of species; and to compare community structure inside versus outside of BIRNM
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