268 research outputs found

    Water renewal mechanisms of the Bay of Algeciras in the Strait of Gibraltar

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    The Bay of Algeciras (BA) is a marine environment subject to high levels of anthropogenic pressure. Here we analyze observations collected at the Bay and the results of an ocean circulation model to investigate its circulation and variability. Special attention is paid to the identification of the mechanisms enhancing the exchange of water with the adjacent Strait of Gibraltar and therefore contributing to maintain satisfactory levels of water quality.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    What does cause the collapse of the western Alboran gyre?

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    The stability of the Western Alboran Gyre (WAG) is investigated on the basis of the outputs of a state-of-the-art Operational Oceanography System of the Strait of Gibraltar and the Alboran Sea. The system is based on a high-resolution (up to 500 m within Gibraltar) primitive-equation circulation model (MIT General Circulation Model) nested to a larger-scale model of the Mediterranean Sea. It is forced by tides and atmospheric (momentum, heat, and fresh water) fluxes provided by the Spanish meteorological Agency. Satellite and model SST corresponding to a hindcast run of Autumn 2011 show the classical circulation of the Alboran Sea at the beginning of October, characterized by the presence of two well developed anticyclonic gyres with the Atlantic jet flowing north-east at the exit of the strait to surround the WAG. This configuration breaks down within a time-scale of three weeks. In a first stage, the WAG undergoes a noticeable weakening and moves slightly to the east. This, in turn, makes possible the (natural) southward veering of the Atlantic jet and the formation of a new gyre on the African coast. It is shown that the WAG perturbations that triggers the sequence is produced by an event of vortex-vortex interaction between the WAG and a cyclonic gyre generated between the Atlantic Jet and Spanish coast. The development of the cyclonic gyre is explained in terms of the advection of tidally-induced positive shear vorticity generated near the lateral boundaries of the Strait of Gibraltar.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    Modelo hidrodinámico de alta resolución del puerto de Algeciras – proyecto SAMPA2

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    El proyecto SAMPA, financiado por la Autoridad Portuaria de la BahĂ­a de Algeciras (APBA) y Puertos del Estado entre los años 2010 y 2013, fue proyecto piloto para la integraciĂłn de un modelo numĂ©rico de alta resoluciĂłn en un sistema operacional en el cual el Grupo de OceanografĂ­a FĂ­sica de la Universidad de MĂĄlaga (GOFIMA) desarrollĂł el propio modelo hidrodinĂĄmico [Sammartino et al., 2014; SĂĄnchez Garrido et al., 2014]. Los productos operacionales servidos por Puertos del Estado (portal PORTUS) y la APBA (sistema CMA), alimentados entre otros por las predicciones derivadas de SAMPA, representaron el primer ejemplo de difusiĂłn de un forecast ocĂ©ano-meteorolĂłgico accesible tanto al pĂșblico generalizado como al personal tĂ©cnico marĂ­timo empleado en el puerto. El modelo numĂ©rico que estaba detrĂĄs de SAMPA, sin embargo, no tenĂ­a suficiente resoluciĂłn para llegar a resolver la dinĂĄmica portuaria, y la APBA, en el 2015, financiĂł la segunda generaciĂłn del proyecto (SAMPA2), con el objetivo de cubrir ese hueco. Entre la segunda mitad del 2015 y durante todo el 2016, despuĂ©s de haber realizado un atento anĂĄlisis de los aspectos mejorables del actual SAMPA, GOFIMA desarrollĂł un sistema completamente nuevo: un modelo anidado en tres dominios acoplados, que proporciona un aumento progresivo de resoluciĂłn desde la escala regional hasta la portuaria. A eso se añade el valor añadido de unas herramientas de anĂĄlisis de calidad de agua del Puerto de Algeciras de acuerdo con las indicaciones de la ROM5.1-13.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    A numerical model analysis of the tidal ïŹ‚ows in the Bay of Algeciras, Strait of Gibraltar

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    A numerical model has been applied to study the tidal flows of the Bay of Algeciras in the eastern part of the Strait of Gibraltar, focusing on the M-2 semidiurnal constituent. The numerical model was satisfactorily validated against a comprehensive set of observations collected in the bay in the year 2011 and the model outputs were used for a detailed analysis of the local tidal circulation. The M-2 net (vertically integrated) transport across the mouth of the bay has an amplitude of 2.7 x 10(-3) Sv, while that of the sea surface signal is of similar to 30 cm and is in quadrature with this flow. However, the vertically integrated flow is the result of a pronounced baroclinic structure consisting of an upper (S 37.5) layers, whose associated transports are one order of magnitude higher. This reveals a noticeable internal tide that is characterized by an inward (to the head of the bay) propagation and a likely quarter-wave resonance. During the rising tide, Atlantic water from the strait comes in and produces the thickening of the upper (Atlantic) layer in the bay, while Mediterranean water of the lower layer is pushed out to join the Mediterranean water stream that is flowing to the west along the Strait of Gibraltar. During the falling tide, Atlantic water flows out of the bay and incorporates to the eastward flow in the strait. In this tidal phase, Mediterranean water flows into the bay. Therefore, Atlantic and Mediterranean waters accumulate in the bay during the rising and falling tide, respectively. This pattern is opposite to that observed in the strait, where the Mediterranean layer thickens during the rising tide and becomes thinner during the falling tide. This suggests that the internal tide in the bay is basically determined by the baroclinic forcing at its mouth imposed by the baroclinic tide of the Strait of Gibralta

    Pet Society App

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    En este presente trabajo, los integrantes de este nuevo proyecto y tambiĂ©n estudiantes de diferentes carreras en la Universidad Peruana de Ciencias Aplicadas, brindaremos una aplicaciĂłn llamada Pet Society que queremos brindarle a cada persona en Lima la oportunidad de acceder a una plataforma Ășnica, sencilla y eficaz para que puedan obtener el mejor servicio asociado a los engreĂ­dos de la casa (sus perritos) en los mejores locales veterinarios en todo Lima Metropolitana, con el fin de hacer esta bĂșsqueda mĂĄs sencilla, veloz y personalizada con los mejores precios del sector y con el mejor servicio y atenciĂłn garantizada. Asimismo estaremos en constantes innovaciones para mejorar la plataforma, los servicios y realzar los precios accesibles para el mercado veterinario. Cabe recalcar que hemos realizado una profunda investigaciĂłn, con el fin de recabar informaciĂłn valiosa, y de esta manera lograremos tener una eficiente y eficaz atenciĂłn hacia los clientes de nuestro segmento asignado, y que con el tiempo lograremos extender. AdemĂĄs, se busca satisfacer las necesidades bĂĄsicas de los dueños con respecto a sus mascotas, brindando un servicio diferenciado de alta calidad y fĂĄcil acceso. Nuestra plataforma tiene como objetivo conectar a las veterinarias con clientes potenciales que busquen satisfacer las necesidades de sus mascotas, generando un incremento de ventas a las empresas veterinarias y una cartera de opciones a los clientes para que puedan escoger el mejor servicio que estos consideren segĂșn sus necesidades. Por esta razĂłn, en el proceso de investigaciĂłn se tomarĂĄn en cuenta las entrevistas y mĂ©tricas para obtener una retroalimentaciĂłn acertada para el proyecto.In this present work, the members of this new project and also students of different careers at the Peruvian University of Applied Sciences, we will provide an application called Pet Society that we want to give each person in Lima the opportunity to access a unique, simple and effective so that they can obtain the best service associated with the cocky of the house (their dogs) in the best veterinary premises throughout Metropolitan Lima, in order to make this search easier, faster and more personalized with the best prices in the sector and with the best service and attention guaranteed. Likewise, we will be constantly innovating to improve the platform, services and enhance accessible prices for the veterinary market. It should be noted that we have carried out a thorough investigation, in order to gather valuable information, and in this way, we will achieve efficient and effective service to customers in our assigned segment, and that over time we will be able to extend. In addition, it seeks to satisfy the basic needs of the owners with respect to their pets, providing a differentiated service of high quality and easy access. Our platform aims to connect veterinarians with potential clients who seek to satisfy the needs of their pets, generating an increase in sales to veterinary companies and a portfolio of options for clients so that they can choose the best service that they consider according to their needs. For this reason, the research process will take into account the interviews and metrics to obtain accurate feedback for the project.Trabajo de investigaciĂł

    Design Strategies for Aptamer-Based Biosensors

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    Aptamers have been widely used as recognition elements for biosensor construction, especially in the detection of proteins or small molecule targets, and regarded as promising alternatives for antibodies in bioassay areas. In this review, we present an overview of reported design strategies for the fabrication of biosensors and classify them into four basic modes: target-induced structure switching mode, sandwich or sandwich-like mode, target-induced dissociation/displacement mode and competitive replacement mode. In view of the unprecedented advantages brought about by aptamers and smart design strategies, aptamer-based biosensors are expected to be one of the most promising devices in bioassay related applications

    Biosensor Applications in the Field of Antibiotic Research—A Review of Recent Developments

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    Antibacterials are among of the most important medications used in health care. However, their efficacy is increasingly impeded by a tremendous and globally spread bacterial resistance phenomenon. This bacterial resistance is accelerated by inadequate application of antibacterial drugs in humans, the widespread veterinary use of antibacterials, and antibacterial occurrence in the environment and food. Further, there is a lack of development of innovative novel drugs. Therefore, the search for novel antibacterials has to be intensified and the spread of antibacterials in the environment has to be restricted. Due to the fundamental progress in biosensor development and promising applications in the antibiotic field, this review gives for the first time an overview on the use and prospects of biosensor applications in that area. A number of reports have applied biosensors of different design and techniques to search for antibacterials in environmental and foodstuff matrices. These studies are discussed with respect to the analytical values and compared to conventional techniques. Furthermore, biosensor applications to elucidate the mode of action of antimicrobial drugs in vitro have been described. These studies were critically introduced referring to the informational value of those simulations. In summary, biosensors will be illustrated as an innovative and promising, although not yet comprehensively applied, technique in the antibacterial field

    A Functional oriT in the Ptw Plasmid of Burkholderia cenocepacia Can Be Recognized by the R388 Relaxase TrwC

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    Burkholderia cenocepacia is both a plant pathogen and the cause of serious opportunistic infections, particularly in cystic fibrosis patients. B. cenocepacia K56-2 harbors a native plasmid named Ptw for its involvement in the Plant Tissue Watersoaking phenotype. Ptw has also been reported to be important for survival in human cells. Interestingly, the presence of PtwC, a homolog of the conjugative relaxase TrwC of plasmid R388, suggests a possible function for Ptw in conjugative DNA transfer. The ptw region includes Type IV Secretion System genes related to those of the F plasmid. However, genes in the adjacent region shared stronger homology with the R388 genes involved in conjugative DNA metabolism. This region included the putative relaxase ptwC, a putative coupling protein and accessory nicking protein, and a DNA segment with high number of inverted repeats and elevated AT content, suggesting a possible oriT. Although we were unable to detect conjugative transfer of the Ptw resident plasmid, we detected conjugal mobilization of a co-resident plasmid containing the ptw region homologous to R388, demonstrating the cloned ptw region contains an oriT. A similar plasmid lacking ptwC could not be mobilized, suggesting that the putative relaxase PtwC must act in cis on its oriT. Remarkably, we also detected mobilization of a plasmid containing the Ptw oriT by the R388 relaxase TrwC, yet we could not detect PtwC-mediated mobilization of an R388 oriT-containing plasmid. Our data unambiguously show that the Ptw plasmid harbors DNA transfer functions, and suggests the Ptw plasmid may play a dual role in horizontal DNA transfer and eukaryotic infection

    Aptamer-Functionalized Nano-Biosensors

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    Nanomaterials have become one of the most interesting sensing materials because of their unique size- and shape-dependent optical properties, high surface energy and surface-to-volume ratio, and tunable surface properties. Aptamers are oligonucleotides that can bind their target ligands with high affinity. The use of nanomaterials that are bioconjugated with aptamers for selective and sensitive detection of analytes such as small molecules, metal ions, proteins, and cells has been demonstrated. This review focuses on recent progress in the development of biosensors by integrating functional aptamers with different types of nanomaterials, including quantum dots, magnetic nanoparticles (NPs), metallic NPs, and carbon nanotubes. Colorimetry, fluorescence, electrochemistry, surface plasmon resonance, surface-enhanced Raman scattering, and magnetic resonance imaging are common detection modes for a broad range of analytes with high sensitivity and selectivity when using aptamer bioconjugated nanomaterials (Apt-NMs). We highlight the important roles that the size and concentration of nanomaterials, the secondary structure and density of aptamers, and the multivalent interactions play in determining the specificity and sensitivity of the nanosensors towards analytes. Advantages and disadvantages of the Apt-NMs for bioapplications are focused
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