6,573 research outputs found

    Cwatset Isomorphism and its Consequences

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    We explore the consequences of cwatset isomorphism (there are a finite number of non-isomorphic cwatsets of each order) and consider parallels between the theory of groups and the theory of cwatsets (cwatsets of prime order are cyclic but direct sums of isomorphic cwatsets aren\u27t necessarily isomorphic)

    Cartography interpreted of soil : San Carlos, Mendoza (Argentina)

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    El objetivo del trabajo fue generar mapas y asociarlos a bases de datos digitales donde se puedan consultar, en forma automatizada y eficiente, preguntas temáticas y por localización. No importa la cartografía en sí misma, sino el análisis, la interpretación y el establecimiento de indicadores de aptitudes edáficas a partir de información geográfica sistematizada. La Información básica es confiable y posee la máxima integridad. Con IDRISI se realizó, con las bandas 5, 4 Y 3 una composición en falso color. Se elaboraron mapas digitalizados de clasificación no supervisada de cobertura del suelo. Se confeccionó, en Access, una base de datos con 26 registros de determinaciones edáficas. Se exportó esta información temática a IDRISI versión 2.0. Con IDRISI se cartografiaron diferentes campos de la base de datos, lo que estableció distintas zonas pilotos en las que se realizó análisis espacial. De estos análisis se crearon mapas temáticos en formato digital. Con otra base de datos reales de 20 registros se convalidaron los resultados de las cartografías realizadas. El trabajo expresa una visión general real de las características edáficas superficiales más importantes y las cartografías cas realizadas tienen valor práctico al establecer indicadores que sirven para quienes tengan conocimientos edafológicos medios.The objective of the work is to generate maps and to associate them to digital databases. Where the databas es are immediately available and thematic and localization questions can be consulted in automated, efficient and effective formo The basis is not only the cartography by itself but also to analyse, to interpret, to create knowledge, to set indicators of edaphic aptitudes, starting from the data and systematized geographical information. The basic information is reliable and it possesses the maximum integrity. With IDRISI a composition in false color, with the bands 5, 4 and 3 was carried out. Digitized maps of not supervised classification of covering of the soil were elaborated. In Access a database with 26 registrations of edaphic determinations was created. Thematic information was exported to IDRIS1 version 2:0. In IDRISI different fields of the database were established different control areas in those that space analyses was carried out. From these analyses thematic maps were created in digital formato With another database of 20 registrations, the results of temáti¬ the carried out cartographies was authenticated. The work expresses a general vision of the most important characteristic of surface soil and the thematic cartographies carried out have an important practical value, specially for those who have average edaphic knowledge.Fil: Perez Valenzuela, Benjamín R.. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: De Cara, Daniel E. . Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Lipinski, Víctor M. . Universidad Nacional de Cuyo. Facultad de Ciencias Agraria

    Combining M-FISH and Quantum Dot technology for fast chromosomal assignment of transgenic insertions

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    <p>Abstract</p> <p>Background</p> <p>Physical mapping of transgenic insertions by Fluorescence in situ Hybridization (FISH) is a reliable and cost-effective technique. Chromosomal assignment is commonly achieved either by concurrent G-banding or by a multi-color FISH approach consisting of iteratively co-hybridizing the transgenic sequence of interest with one or more chromosome-specific probes at a time, until the location of the transgenic insertion is identified.</p> <p>Results</p> <p>Here we report a technical development for fast chromosomal assignment of transgenic insertions at the single cell level in mouse and rat models. This comprises a simplified 'single denaturation mixed hybridization' procedure that combines multi-color karyotyping by Multiplex FISH (M-FISH), for simultaneous and unambiguous identification of all chromosomes at once, and the use of a Quantum Dot (QD) conjugate for the transgene detection.</p> <p>Conclusions</p> <p>Although the exploitation of the unique optical properties of QD nanocrystals, such as photo-stability and brightness, to improve FISH performance generally has been previously investigated, to our knowledge this is the first report of a purpose-designed molecular cytogenetic protocol in which the combined use of QDs and standard organic fluorophores is specifically tailored to assist gene transfer technology.</p

    Magnetic translation groups in an n-dimensional torus

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    A charged particle in a uniform magnetic field in a two-dimensional torus has a discrete noncommutative translation symmetry instead of a continuous commutative translation symmetry. We study topology and symmetry of a particle in a magnetic field in a torus of arbitrary dimensions. The magnetic translation group (MTG) is defined as a group of translations that leave the gauge field invariant. We show that the MTG on an n-dimensional torus is isomorphic to a central extension of a cyclic group Z_{nu_1} x ... x Z_{nu_{2l}} x T^m by U(1) with 2l+m=n. We construct and classify irreducible unitary representations of the MTG on a three-torus and apply the representation theory to three examples. We shortly describe a representation theory for a general n-torus. The MTG on an n-torus can be regarded as a generalization of the so-called noncommutative torus.Comment: 29 pages, LaTeX2e, title changed, re-organized, to be published in Journal of Mathematical Physic

    Characteristics of survivors: growth and nutritional condition of early stages of the hake species Merluccius paradoxus and M. capensis in the southern Benguela ecosystem

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    Larval mortality in marine fish is strongly linked to characteristic traits such as growth and condition, but the variability in these traits is poorly understood. We tried to identify the variability in growth in relation to conditions leading to greater survival chances for early stages of Cape hake, Merluccius paradoxus and M. capensis, in the Benguela upwelling ecosystem. During two cruises in 2007 and one cruise in 2008, hake larvae and juveniles were caught. Otolith microstructures revealed a larval age ranging from 2 to 29 days post-hatching (dph), whereas juvenile age was 67–152 dph. RNA:DNA ratios, used to evaluate nutritional condition, were above the relevant threshold level for growth. No strong coupling between growth and condition was detected, indicating a complex relationship between these factors in the southern Benguela ecosystem. Merluccius paradoxus juveniles caught in 2007 (the surviving larvae of 2006) had significantly higher larval growth rates than larvae hatched in 2007 and 2008, possibly indicating selection for fast growth in 2006. High selection pressure on growth could be linked to predation avoidance, including cannibalism

    Chokka squid on the Agulhas Bank: life history and ecology

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    Available knowledge is reviewed and new data incorporated in a synthesis of the life history and ecology of the chokka squid Loligo vulgaris reynaudii. We attempt to show that these aspects are essential to rational management of the resource. The life cycle is descriptionbed in detail from the egg to adult stage, mainly in biological terms, including a comprehensive descriptionption of maturation, migration and reproduction. Possible ecological interactions, particularly those of paralarvae and copepods, are discussed. Predator-prey relationships and the current state of knowledge on the effect of the physical environment on squid availability and abundance are summarized

    Future challenges in cephalopod research

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    We thank Anto´nio M. de Frias Martins, past President of the Unitas Malacologica and Peter Marko, President of the American Malacological Society for organizing the 2013 World Congress of Malacology, and the Cephalopod International Advisory Committee for endorsing a symposium held in honour of Malcolm R. Clarke. In particular, we would like to thank the many professional staff from the University of the Azores for their hospitality, organization, troubleshooting and warm welcome to the Azores. We also thank Malcolm Clarke’s widow, Dorothy, his daughter Zoe¨, Jose´ N. Gomes-Pereira and numerous colleagues and friends of Malcolm’s from around the world for joining us at Ponta Delgada. We are grateful to Lyndsey Claro (Princeton University Press) for granting copyright permissions.Peer reviewedPublisher PD
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