195 research outputs found

    Palladium-catalysed hydroxylation and alkoxylation

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The formation of oxygen–carbon bonds is one of the fundamental transformations in organic synthesis. In this regard the application of palladium-based catalysts has been extensively studied during recent years. Nowadays it is an established methodology and the success has been proven in manifold synthetic procedures. This tutorial review summarizes the advances on palladium-catalysed C–O bond formation, means hydroxylation and alkoxylation reactions.DFG, EXC 314, Unifying Concepts in Catalysi

    Integrated study of Mediterranean deep canyons: Novel results and future challenges

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    This volume compiles a number of scientific papers resulting from a sustained multidisciplinary research effort of the deep-sea ecosystem in the Mediterranean Sea. This started 20 years ago and peaked over the last few years thanks to a number of Spanish and European projects such as PROMETEO, DOS MARES, REDECO, GRACCIE, HERMES, HERMIONE and PERSEUS, amongst others. The geographic focus of most papers is on the NW Mediterranean Sea including the Western Gulf of Lion and the North Catalan margin, with a special attention to submarine canyons, in particular the Blanes and Cap de Creus canyons. This introductory article to the Progress in Oceanography special issue on "Mediterranean deep canyons" provides background information needed to better understand the individual papers forming the volume, comments previous reference papers related to the main topics here addressed, and finally highlights the existing relationships between atmospheric forcing, oceanographic processes, seafloor physiography, ecosystem response, and litter and chemical pollution. This article also aims at constituting a sort of glue, in terms of existing knowledge and concepts and novel findings, linking together the other twenty papers in the volume, also including some illustrative figures. The main driving ideas behind this special issue, particularly fitting to the study area of the NW Mediterranean Sea, could be summarized as follows: (i) the atmosphere and the deep-sea ecosystem are connected through oceanographic processes originating in the coastal area and the ocean surface, which get activated at the occasion of high-energy events leading to fast transfers of matter and energy to the deep; (ii) shelf indented submarine canyons play a pivotal role in such transfers, which involve dense water, sedimentary particles, organic matter, litter and chemical pollutants; (iii) lateral inputs (advection) from the upper continental margin contributes significantly to the formation of intermediate and deep-water masses, and the associated fluxes of matter and energy are a main driver of deep-sea ecosystems; (iv) deep-sea organisms are highly sensitive to the arrival of external inputs, starting from the lowest food web levels and propagating upwards as time passes, which also relies upon the biology, nutritional needs and life expectancy of each individual species; and (v) innovative knowledge gained through such multidisciplinary research is of the utmost significance for an improved management of deep-sea living resources, such as the highly priced red shrimp Aristeus antennatus, for which a pilot management plan largely based in the findings described here and in related articles has been recently published (BOE, 2013). The researchers involved in such challenging endeavour have learnt tremendously from the results obtained so far and from each other, but are fully aware that there are still many unsolved questions. That is why this introductory article also includes "Future challenges" both in the title and as an individual section at the end, to express that there is still a long way to go

    Isolation of Key Organometallic Aryl-Co(III) Intermediates in Cobalt-Catalyzed C(sp2)–H Functionalizations and New Insights into Alkyne Annulation Reaction Mechanisms

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    The selective annulation reaction of alkynes with substrates containing inert C–H bonds using cobalt as catalyst is currently a topic attracting significant interest. Unfortunately, the mechanism of this transformation is still relatively poorly understood, with little experimental evidence for intermediates, although an organometallic Co(III) species is generally implicated. Herein, we describe a rare example of the preparation and characterization of benchtop-stable organometallic aryl-Co(III) compounds (NMR, HRMS, XAS, and XRD) prepared through a C(sp2)–H activation, using a model macrocyclic arene substrate. Furthermore, we provide crystallographic evidence of an organometallic aryl-Co(III) intermediate proposed in 8-aminoquinoline-directed Co-catalyzed C–H activation processes. Subsequent insights obtained from the application of our new organometallic aryl-Co(III) compounds in alkyne annulation reactions are also disclosed. Evidence obtained from the resulting regioselectivity of the annulation reactions and DFT studies indicates that a mechanism involving an organometallic aryl-Co(III)-alkynyl intermediate species is preferred for terminal alkynes, in contrast to the generally accepted migratory insertion pathway

    KOSTASystem, a multipurpose coastal videometry system

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    This contribution presents the KOSTASystem technology, a multipurpose coastal videometry system. It is implemented in 20 operational stations distributed along the Basque Coast (Spain), covering urban and natural beaches, port protection structures and natural coastal stretches. The purpose of this technology is to provide basic quantitative and qualitative data for coastal management applications. The most representative advances are related to the hardware, with the development of autonomous photovoltaic stations, and to the software, developing several tools for the calibration and restitution of the images and for the extraction of the information used in the different applications. In the longterm, within a climate change context, the most essential results have been obtained in the monitoring of beach morphology. In the short-term, the camera network works under extreme wave conditions, monitoring wave overtopping and flooding. Apart from this, it is also used for the daily management of the beaches in the summer season, improving the safety by detecting and predicting rip currents and providing information about beach user density (BUD). Finally, the constant improvement of this technology and its applications help to grow and collaborate within the European framework of the coastal observation network.Peer Reviewe

    Comparison between ROV video and Agassiz trawl methods for sampling deep water fauna of submarine canyons in the Northwestern Mediterranean Sea with observations on behavioural reactions of target species

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    In this paper we present a comparison between Remotely Operated Vehicle (ROV) and Agassiz trawling methods for sampling deep-water fauna in three submarine canyons of the Northwestern Mediterranean Sea and describe the behavioural reactions of fishes and crustacean decapods to ROV approach. 10 ROV dives, where 3583 individuals were observed and identified to species level, and 8 Agassiz trawls were carried out in a depth range of 750-1500 m. As noticed in previous studies, abundances of fishes and decapod crustaceans were much higher in the ROV videos than in Agassiz trawl samples, as the latter are designed for the retrieval of benthic, less motile species in permanent contact with the bottom. In our observations fish abundance was one order of magnitude higher with ROV (4110.22 ind/km2) than with Agassiz trawl (350.88 ind/km2), whereas decapod crustaceans were six times more abundant in ROV videos (6362.40 ind/km2) than in Agassiz samples (1364.52 ind/km2). The behaviour of highly motile fishes was analysed in terms of stationary positioning over the seafloor and avoidance or attraction to ROV approach. The most frequently occurring fish species Coelorinchus mediterraneus, Nezumia aequalis, Bathypterois dubius, Lepidion lepidion, Trachyrincuss scabrus and Polyacanthonotus rissoanus did not react to the presence of the ROV in most cases (>50%). Only B. dubius (11%), Lepidion lepidion (14.8%), P. rissoanus (41%) and T. scabrus (14.3%) reacted to ROV approach. More than 60% of less motile species, such as crustacean decapods, did not respond to ROV presence either. Only 33.3% of Geryon longipes, 36.2% of Munida spp. and 29.79% of Pagurus spp. were observed avoiding or defensively reacting to the ROV. The comparison of results obtained with ROV and trawl sampling is of ecological relevance since ROV can report observations in areas where trawling is technically unfeasible. The lack of reaction by most fish and crustacean decapod specimens further confirms that ROV surveying is an efficient technique to assess abundance and species composition in deep-sea waters for these motile species and questions trawl-based estimations

    La casa del Marxucal d'Oliva: Projecte de restauraciĂł

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    L’article tracta sobre un projecte de restauració de la casa del Marxucal, construcció rural situada en el terme municipal d’Oliva. En ell es descriuen aspectes com la situació geogràfica i el context històric de la casa, s’hi fa un alçament planimètric de l’estat actual i una descripció detallada dels materials, de les tècniques constructives utilitzades i dels danys estructurals. A més, s’hi fa un recorregut per les diferents teories de la restauració d’alguns dels autors més destacats en aquest camp. També s’hi descriuen els criteris de projecte a seguir i s’hi fa una reconstrucció d’elements, una planimetria de projecte i de detalls constructius i una simulació d’alguns resultats de la intervenció. El projecte fou realitzat col·lectivament, durant el curs 2010-2011, per a l’assignatura de cinquè curs “Restauració Arquitectònica”, impartida per la professora Camila Mileto, del departament de Composició Arquitectònica de la Universitat Politècnica de Valènci

    A novel and multi-purpose ASV for the Basque Coast: design, experimental testing, and main challenges

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    Autonomous Surface Vehicles (ASVs) have become a powerful tool for marine research due to their capability to make observations over a wide range of temporal and spatial scales. ASVs provide accurate, high-resolution, continuous data, benefiting environmental monitoring by decreasing the costs when compared to fully manned vessels. In the framework of Oarsoaldea Blue Hub project, a 6 m length electrical ASV equipped with acoustic sensors for measuring water currents and fish biomass has been designed and developed as a solution for more efficient oceanographic observations in the coastal area.Peer Reviewe

    Assembly Birmingham: opportunities and challenges in a redeveloping city

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    Anna Francis presented the challenges and opportunities of running an artist led gallery in Stoke-on-Trent, via a number of projects and exhibitions which AirSpace Gallery (where Anna Francis has been a director since 2013) have been undertaking since being established in the city in 2006. The presentation was within the first panel of the A-N (Artist Information Company) Assembly Birmingham Event in 2018. 'The second a-n Assembly event for 2018 will take place at Eastside Projects in Birmingham, an artist-led gallery space established in 2008. Working in collaboration with artist and curator Antonio Roberts, Assembly Birmingham will address the increasing amount of development taking place across the city and the Midlands as a whole, exploring both the opportunities and the challenges this presents for the visual arts community in the region. Through a mix of presentations, discussions, artist film and a specially commissioned soundwalk through Digbeth, Assembly Birmingham will explore these competing tensions, reflecting on the opportunities artists have already built for themselves, and consider what investment and change could mean in the future. Opportunity Cost invites Directors from four Midlands-based galleries and projects to reflect on the journey of establishing their spaces. Through a series of short presentations the speakers will discuss what factors went into choosing where to set up their spaces and, with investment in redevelopment increasing, what challenges lie ahead. Speakers include: Karolina Korupczynska, Director at Stryx, Cheryl Jones, Director at Grand Union, Anna Francis, Director at Airspace Gallery, and Ryan Hughes, Director of Coventry Biennial.

    Impacts on the Deep-Sea Ecosystem by a Severe Coastal Storm

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    Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem

    The Power in People: Community Maker at Assembly Margate

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    Assembly Margate was the first of the a-n Assembly events to take place during May and June, 2017. Hosted across a number of arts spaces in the town, a-n devised a programme of events with Margate-based social artist Dan Thompson. In Margate, as in much of the South East, the influx of new artists, priced out of London, brought opportunities but also created tensions. Art was a contentious subject in a town with some of the most deprived areas in England. With a small population and a huge variety of studio spaces, galleries and artist-led projects, there were further tensions between the diverse groups of artists as they found new spaces, new ways of working, and new ways to fund their work in the town. The Assembly events in part responded to this context, with formal talks and workshops complemented by artist-led tours, a social night out and opportunities for networking and discussions with fellow artists and the a-n team
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