5,957 research outputs found

    Reconciling opposing views on carbon cycling in the coastal ocean: continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2

    Full text link
    Despite their moderately-sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of carbon and nutrients, sustaining a disproportionate large biological activity compared to their relative surface area. A synthesis of worldwide measurements of the partial pressure of CO2 (pCO2) indicates that most open shelves in the temperate and high latitude regions are under-saturated with respect to atmospheric CO2 during all seasons, although the low latitude shelves seem to be over-saturated. Most inner estuaries and near-shore coastal areas on the other hand are over-saturated with respect to atmospheric CO2. The scaling of air-sea CO2 fluxes based on pCO2 measurements and carbon mass balance calculations indicate that the continental shelves absorb atmospheric CO2 ranging between 0.33 to 0.36 Pg C yr-1 that corresponds to an additional sink of 27% to ~30% of the CO2 uptake by the open oceans based on the most recent pCO2 climatology (Takahashi et al., 2008; Deep-Sea Research II, this issue). Inner estuaries, salt marshes and mangroves emit up to 0.50 Pg C yr-1, although these estimates are prone to large uncertainty due to poorly constrained ecosystem surface area estimates. Nevertheless, the view of continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2 allows reconciling long-lived opposing views on carbon cycling in the coastal ocean

    Mapping sustainability transitions in contemporary culture

    Get PDF
    This presentation draws from research conducted at an ongoing project, ‘SPLACH – Spatial Planning for Change’, which aims to inform a sustainability transition of the Lisbon Metropolitan Area urban planning, towards an improved food system, responding to contemporary cultural concerns. But where does contemporary culture really stand with respect to sustainability? Among many contenders for supplanting postmodernism, we would emphasize hypermodernism, digimodernism, metamodernism and transmodernism, since in many respects, these paradigmatic views are engaged with a sustainability transition. Here, we assess how history, technology and visual culture are valued in contemporaneity. This is done by intersecting our readings of cultural paradigms with key ideas about sustainability, drawn from the SPLACH literature review. Moreover, we highlight opportunities for urban design to accomodate a change towards sustainable urban environments.info:eu-repo/semantics/publishedVersio

    The role of food in re-imagining the city: From the neighbourhood to the region

    Get PDF
    Humanity is now believed to live in a new geological epoch, the Anthropocene, as changes have been reported on the atmosphere, air, water, and soil, but also on societal perceptions of these issues. This presentation departs from the theoretical assumption that the impact of the abovementioned changes on culture and the environment have not yet found a stable influence on urban planning. This presentation overviews the implications of the food system within urban planning while considering it as a socio-technical system which integrates production, distribution, transformation, consumption and disposal patterns. The production phase of the food system in particular, emerges as a fundamental planning challenge, extending to urban form solutions, individual behaviours, dietary regimes, inequalities in foodsheds planning, and the cultural capital of food. Accordingly, the food system emerges here as an opportunity to identify how current urban fabrics of cities and their rural and regional hinterlands can be transformed in terms of their metabolic function and respond to the needs of people and the environment. To do so, this presentation introduces the preliminary results of an analysis conducted by an ongoing research project SPLACH – Spatial Planning for Change, at two particular scales: the region and the neighbourhood. Thus, while focusing in the Lisbon Metropolitan Area (LMA), in Portugal, we provide an analysis of the Regional Plan as well as of specific residential neighbourhoods located in LMA, regarding the relationship between the food system functioning and urban planning approaches. The analysis includes a comparative number of case studies which differ in urban form solutions, socio-economic conditions, but also geographical location. The results support the request for a stronger integration of the above-identified underexplored topics of the food system within urban planning, which will be fundamental to inform a new theory of the city that makes any serious contribution towards a sustainability transition.info:eu-repo/semantics/publishedVersio

    When Lisbon met the Team 10 Cluster City

    Get PDF
    After the Doorn Manifesto (1954), Team 10 members synthesize their earlier projects into a new urban model: the Cluster City. In 1961, the Lisbon Technical Office for Housing (Gabinete Técnico de Habitação) – GTH was established by the municipality to resolve an ongoing housing shortage. Soon, the GTH planned the urbanization of the Chelas Valley, an agricultural area in the East area of Lisbon. This plan tested approaches to neighbourhood planning unprecedented in the municipality. Its Zone I Plan, by Francisco Silva Dias and Luís Vassalo Rosa (1966) was the first to be implemented, echoing in practice the Doorn Manifesto. Here, we identify urban forms used in this Plan, and the ‘ground rules’ that structured it and influenced its change over time. Furthermore, we ask whether Chelas can shed some light in the recent demise of examples like Toulouse-Le Mirail and Robin Hood Gardens.info:eu-repo/semantics/publishedVersio

    Improving the Knowledge on Seismogenic Sources in the Lower Tagus Valley for Seismic Hazard Purposes

    Get PDF
    The Lower Tagus Valley, that includes the metropolitan area of Lisbon, has been struck by several earthquakes which produced significant material damage and loss of lives. Their exact location remains unknown. Our goal is to shed some light into the seismogenic sources in the area using seismic reflection and geological data. In areas with no seismic coverage, potential-field data interpretation was carried out. Seismicity was overlaid to the potential seismogenic structures and high-resolution data was acquired in order to confirm which structures have been active into the Quaternary. Three major fault-zones affecting the Neogene were identified: V. F. Xira, Samora-Alcochete and Pinhal Novo. For the first fault, strong evidences suggest it is active. The other two fault-zones and other structures previously unknown can be correlated with several epicentres. Empirical relationships between maximum moment magnitude and fault area indicate that MW > 6.5 earthquakes can be expected for the larger structures

    Multiple Haemangiomas, Diaphragmatic Eventration and Beckwith-Wiedemann Syndrome: An Unusual Association

    Get PDF
    A 6-month-old girl with Beckwith-Wiedemann syndrome, multiple haemangiomas (axillary, laryngeal, pulmonary and hepatic) and diaphragmatic eventration was reported. All tumours responded to treatment with propranolol. The surgical correction of diaphragmatic eventration was crucial to a better outcome

    An infrared diagnostic for magnetism in hot stars

    Full text link
    Magnetospheric observational proxies are used for indirect detection of magnetic fields in hot stars in the X-ray, UV, optical, and radio wavelength ranges. To determine the viability of infrared (IR) hydrogen recombination lines as a magnetic diagnostic for these stars, we have obtained low-resolution (R~1200), near-IR spectra of the known magnetic B2V stars HR 5907 and HR 7355, taken with the Ohio State Infrared Imager/Spectrometer (OSIRIS) attached to the 4.1m Southern Astrophysical Research (SOAR) Telescope. Both stars show definite variable emission features in IR hydrogen lines of the Brackett series, with similar properties as those found in optical spectra, including the derived location of the detected magnetospheric plasma. These features also have the added advantage of a lowered contribution of stellar flux at these wavelengths, making circumstellar material more easily detectable. IR diagnostics will be useful for the future study of magnetic hot stars, to detect and analyze lower-density environments, and to detect magnetic candidates in areas obscured from UV and optical observations, increasing the number of known magnetic stars to determine basic formation properties and investigate the origin of their magnetic fields.Comment: 4 pages, accepted for publication in A&
    • …
    corecore