Rapid seafloor mapping of the northern Galapagos Islands, Darwin and Wolf

Darwin and Wolf are the most remote of the Galapagos islands and are famous for their remarkable pelagic and benthic marine species abundance and diversity. However, little is known about their surrounding bathymetry. Rapid surveys were carried out in 2008 and 2009 to collect geo-referenced depth soundings down to 100 m around both islands, as a step towards a better understanding of their habitat and species distribution. Five spatial interpolation methods were tested on the data, to find the most accurate. The Triangular Irregular Network (TIN) was the best interpolator for these data sets with the fewest interpolation errors, and was then used to create contour and three dimensional maps of the seafloor topography of both islands. Darwin has a bigger insular platform with gentle submarine slopes whereas Wolf has very steep slopes with a smaller platform

Reestructuración urbana el trébol – la Marín: Centro de convenciones y servicios en la Tola

En el capítulo 1, realizamos un análisis de los diferentes sectores dentro de la zona centro - sur de Quito, los cuales son lugares con problemáticas únicas y potencialidades aprovechables para la elaboración del Trabajo de Fin de Carrera. Aquí se realiza una memoria fotográfica para la creación de una base de datos, realizamos también un análisis de usos de suelos, de valor histórico, identificación de edificaciones importantes, sistemas de movilidad, para luego escoger de entre todas las opciones, el sector en el que se propondrá la propuesta de intervención. En el capítulo 2 analizamos más detalladamente el factor social, económico e histórico del sector escogido, tomando referencias de estudios previos sobre datos demográficos, estadísticas de vivienda y grupos etarios. Realizamos un levantamiento tridimensional donde se ponga en evidencia la topografía del sector y cómo se produce la movilidad. En el capítulo 3, analizamos varias problemáticas del sector que puedan servir como punto de partida para la propuesta. Determinamos el carácter implícito y único de cada barrio, así como los puntos potenciales más importantes de cada uno de los sectores escogidos. Luego, haciendo uso de las teorías estudiadas en el taller, elaboramos un partido conceptual que engloba una resolución a gran escala de uno de los principales problemas del sector, y a partir de esto, generamos los sistemas y subsistemas de intervención urbana de los que se trata nuestra propuesta. En el capítulo 4, escogí un sector dentro de la propuesta urbana donde se implantará mi proyecto arquitectónico y realicé un análisis de las condicionantes topográficas, sociales, funcionales, climáticas, etc. de este terreno específico. Después de esto, se determinó el tipo de arquitectura con el que se debía intervenir, los conceptos fundamentales que dan el carácter del proyecto y las intenciones formales y espaciales. Luego determiné el carácter que le doy al sector mediante la implementación de actividades y servicios. A modo general, propuse una zonificación general en la que se observa la escala de apropiación arquitectónica del terreno y a partir de esto, genero los espacios en función a los conceptos que quiero aplicar en este proyecto. Una vez realizado esto, identifico el partido conceptual y arquitectónico y propongo una propuesta a nivel de anteproyecto en la que se identifiquen todos los factores que llegan desde la propuesta urbana hasta los conceptos y teorías que yo utilizo individualmente. Una vez efectuados todos estos pasos, procedo a determinar una materialidad para el proyecto, como se sostendrá y qué efectos quiero lograr con los materiales que voy a utilizar. En el capítulo 5, se realiza una descripción del producto arquitectónico terminado, en el que las decisiones conceptuales, formales y estructurales se presentan en la forma de planos, fotomontajes, detalles y renders, para dar cuenta de la espacialidad, los distintos espacios y las cualidades constructivas del proyecto

Genetic identification of three CITES-listed sharks using a paper-based Lab-on-a-Chip (LOC)

Threatened shark species are caught in large numbers by artisanal and commercial fisheries and traded globally. Monitoring both which shark species are caught and sold in fisheries, and the export of CITES-restricted products, are essential in reducing illegal fishing. Current methods for species identification rely on visual examination by experts or DNA barcoding techniques requiring specialist laboratory facilities and trained personnel. The need for specialist equipment and/or input from experts means many markets are currently not monitored. We have developed a paper-based Lab-on-a-Chip (LOC) to facilitate identification of three threatened and CITES-listed sharks, bigeye thresher (Alopias superciliosus), pelagic thresher (A. pelagicus) and shortfin mako shark (Isurus oxyrinchus) at market source. DNA was successfully extracted from shark meat and fin samples and combined with DNA amplification and visualisation using Loop Mediated Isothermal Amplification (LAMP) on the LOC. This resulted in the successful identification of the target species of sharks in under an hour, with a working positive and negative control. The LOC provided a simple “yes” or “no” result via a colour change from pink to yellow when one of the target species was present. The LOC serves as proof-of-concept (PoC) for field-based species identification as it does not require specialist facilities. It can be used by non-scientifically trained personnel, especially in areas where there are suspected high frequencies of mislabelling or for the identification of dried shark fins in seizures

Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Propuesta de metodología para el mantenimiento de vías de tercer orden utilizando estabilización con crudos pesados. Caso de estudio: vía Las Maravillas-Tres Esquinas, cantón Paján, provincia de Manabí

El propósito de esta investigación es determinar la posibilidad de utilización de crudos pesados para estabilización de suelos de la zona de afectación, en superficies o capas de rodadura para su aprovechamiento en construcción de caminos vecinales de tránsito liviano a medio, con una reducción notable de costos. Este trabajo intenta establecer el comportamiento del crudo pesado en mezclas de laboratorio con muestras de suelos de préstamo local, las cuales satisfagan las especificaciones y los requerimientos de calidad, sin comprometer mayores inversiones. La provincia de Manabí, con 13,5% del total de la red vial de Ecuador, no dispone de áridos de buena gradación en gran parte de su extensión, es por lo tanto imprescindible encontrar una solución eficaz para la escasez de agregados en las zonas aledañas al proyecto de vía, y suplir esta necesidad con soluciones adaptables al medio y a la realidad socioeconómica del sector

Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark

Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial “cryptic” lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic

Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark

Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (\u3e300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial “cryptic” lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic