23 research outputs found

    Penetration of ultraviolet‐B radiation in oligotrophic regions of the oceans during the Malaspina 2010 expedition

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    Few studies have investigated ultraviolet (UV) radiation in the open ocean besides its harmful effects on organisms and influence on biogeochemical processes. Here, we assessed UV attenuation, with particular focus on UV‐B, across the (sub)tropical ocean during the Malaspina 2010 Circumnavigation. Vertical UV radiometer profiles together with Chl‐ a concentration, and UV absorption by CDOM ( a CDOM ( λ )) and by suspended particulate matter ( a p ( λ )) were measured at 117 stations. At photosynthetically active radiation (PAR) and across UV‐A and UV‐B wavelengths, the lowest downwelling attenuation coefficients ( K d ) during the expedition were recorded in ultra‐oligotrophic regions at 5°–15°S (mean K d (305 nm): 0.129 m −1 , mean K d (313 nm): 0.107 m −1 ) in the Indian and South Pacific Oceans. The waters here were comparatively more transparent than at 5°–15°N (mean K d (305 nm): 0.239 m −1 , mean K d (313 nm): 0.181 m −1 ) where equatorial upwelling occurs. K d was highest near the Costa Rica Dome ( K d (313 nm): 0.226 m −1 ) and at the confluence of the Benguela and Agulhas currents ( K d (313 nm): 0.251 m −1 ). The contribution of a p ( λ ) toward nonwater absorption ( a nw ( λ )) was significantly lower at 305 nm than at 313 and 320 nm, suggesting the contribution of absorption by detritus and phytoplankton particles decreases compared with that of CDOM absorption as UV‐B wavelength decreases. Both a CDOM ( λ ) and a p ( λ ) at UV‐B wavelengths were lowest in the Indian Ocean whereas K d was lowest in the South Pacific. This finding emphasizes that other factors besides absorption, such as scattering by reflective phytoplankton or inorganic particles, strongly influence UV‐B attenuation in open ocean waters.Plain Language Summary: We assessed water transparency to UV‐B radiation across the tropical and subtropical ocean as part of the Malaspina 2010 Expedition. UV‐B radiometer profiles, Chlorophyll‐a, and UV‐B absorption by organic matter and suspended particles were measured at 117 stations. The most UV‐B transparent waters were found in regions where nutrients are extremely low, particularly at 5°–15°S in the Indian and South Pacific Oceans. Here, ocean waters were considerably more transparent than 5°–15°N, which suggests that at a given depth southern hemisphere marine organisms experience higher UV‐B exposure than their northern counterparts. The least UV‐B transparent waters were near the Costa Rica Dome and at the confluence of the Benguela and Agulhas currents. UV‐B absorption by organic matter and suspended particles, and Chl‐ a concentration were lowest in the Indian Ocean. The contribution of suspended particles toward nonwater absorption was significantly lower at 305 nm than at 313 and 320 nm, and higher in the clearest waters of the Indian Ocean than in the Subtropical South Pacific. Absorptions by organic matter and suspended particles were lowest in the Indian Ocean whereas UV‐B attenuation was lowest in the South Pacific, which highlights the complex relationship between optical properties in the UV‐B spectrum.Ministerio de Ciencia e InnovaciĂłn | Ref. CSD2008-00077King Abdullah University of Science and Technology | Ref. BAS/1/1072-01-0

    Where Nothing Happened: The Experience of War Captivity and Levinas’s Concept of the ‘There Is’

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    This article takes as its subject matter the juridico-political space of the prisoner of war (POW) camp. It sets out to determine the nature of this space by looking at the experience of war captivity by Jewish members of the Western forces in World War II, focusing on the experience of Emmanuel Levinas, who spent 5 years in German war captivity. On the basis of a historical analysis of the conditions in which Levinas spent his time in captivity, it argues that the POW camp was a space of indifference that was determined by the legal exclusion of prisoners from both war and persecution. Held behind the stage of world events, prisoners were neither able to exercise their legal agency nor released from law into a realm of extra-legal violence. Through a close reading of Levinas’s early concept of the ‘there is’ [il y a], the article seeks to establish the impact on prisoners of prolonged confinement in such a space. It sets out how prisoners’ subjectivity dissolved in the absence of meaningful relations with others and identifies the POW camp as a space in which existence was reduced to indeterminate, impersonal being

    Data set accompanying the article: Unraveling the Seasonality of UV Exposure in Reef Waters of a Rapidly Warming (Sub-)tropical Sea

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    This data set comprises of the underlying data used in Figures 2 (incident UV), 3 & 6 (Temperature, Chl-a and aCDOM), 4 (Kd), 5 (in situ UV exposure) and 7 (projected temperature and UV-B) of the publication entitled "Unraveling the Seasonality of UV Exposure in Reef Waters of a Rapidly Warming (Sub-)tropical Sea". Keywords: Red Sea, coral reefs, marine optics, ultraviolet radiation (UV), daily UV exposure, downwelling diffuse attenuation coefficient (Kd), chlorophyll-a, CDOM, temperature, seasonality, climate chang

    Data set accompanying the article: Unraveling the Seasonality of UV Exposure in Reef Waters of a Rapidly Warming (Sub-)tropical Sea

    No full text
    This data set comprises of the underlying data used in Figures 2 (incident UV), 3 & 6 (Temperature, Chl-a and aCDOM), 4 (Kd), 5 (in situ UV exposure) and 7 (projected temperature and UV-B) of the publication entitled "Unraveling the Seasonality of UV Exposure in Reef Waters of a Rapidly Warming (Sub-)tropical Sea". Keywords: Red Sea, coral reefs, marine optics, ultraviolet radiation (UV), daily UV exposure, downwelling diffuse attenuation coefficient (Kd), chlorophyll-a, CDOM, temperature, seasonality, climate chang

    MALASPINA 2010 optical data: aCDOM_aParticles_Kd_Z10%

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    The dataset is comprised of: downwelling diffuse attenuation coefficients, Z10%, aCDOM and apTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

    The effect of simulations and games on learning objectives in tertiary education : A systematic review

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    The growing popularity of simulations and games invites the production of insights that help academic teachers to use simulations and games in their courses. This article clarifies positive conditions to use simulations and games in tertiary education. Based on a systematic review of literature we tentatively find a positive or neutral relationship between using simulations and games and achieving learning objectives. Also, we find three recurring conditions for successful use of simulations and games: the specificity of the game, the integration in the course, and the role of a guiding instructor. Finally, we express the strong need for a scientific framework to measure effectiveness of simulations and games

    Penetration of Ultraviolet-B Radiation in Oligotrophic Regions of the Oceans During the Malaspina 2010 Expedition

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    21 pages, 4 tables, 8 figures.-- This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs LicenseFew studies have investigated ultraviolet (UV) radiation in the open ocean besides its harmful effects on organisms and influence on biogeochemical processes. Here, we assessed UV attenuation, with particular focus on UV-B, across the (sub)tropical ocean during the Malaspina 2010 Circumnavigation. Vertical UV radiometer profiles together with Chl-a concentration, and UV absorption by CDOM (aCDOM(λ)) and by suspended particulate matter (ap(λ)) were measured at 117 stations. At photosynthetically active radiation (PAR) and across UV-A and UV-B wavelengths, the lowest downwelling attenuation coefficients (Kd) during the expedition were recorded in ultra-oligotrophic regions at 5°–15°S (mean Kd(305 nm): 0.129 m−1, mean Kd(313 nm): 0.107 m−1) in the Indian and South Pacific Oceans. The waters here were comparatively more transparent than at 5°–15°N (mean Kd(305 nm): 0.239 m−1, mean Kd(313 nm): 0.181 m−1) where equatorial upwelling occurs. Kd was highest near the Costa Rica Dome (Kd(313 nm): 0.226 m−1) and at the confluence of the Benguela and Agulhas currents (Kd(313 nm): 0.251 m−1). The contribution of ap(λ) toward nonwater absorption (anw(λ)) was significantly lower at 305 nm than at 313 and 320 nm, suggesting the contribution of absorption by detritus and phytoplankton particles decreases compared with that of CDOM absorption as UV-B wavelength decreases. Both aCDOM(λ) and ap(λ) at UV-B wavelengths were lowest in the Indian Ocean whereas Kd was lowest in the South Pacific. This finding emphasizes that other factors besides absorption, such as scattering by reflective phytoplankton or inorganic particles, strongly influence UV-B attenuation in open ocean watersThis study was funded by the Spanish Ministry of Economy and Competitiveness through the Malaspina 2010 Expedition project (Consolider-Ingenio 2010; MICINN CSD2008-00077). The PhD fellowship of SO was supported by the baseline funding from KAUST to S. AgustĂ­ under award number BAS/1/1072-01-01Peer reviewe

    MALASPINA 2010 optical data: aCDOM_aParticles_Kd_Z10%

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    The dataset is comprised of: downwelling diffuse attenuation coefficients, Z10%, aCDOM and ap.Peer reviewe

    MALASPINA 2010 optical data: aCDOM_aParticles_Kd_Z10%

    No full text
    The dataset is comprised of: downwelling diffuse attenuation coefficients, Z10%, aCDOM and apPeer reviewe
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