1,721,017 research outputs found
Biodiversity conservation in the coastal zone of Viet Nam (Bao Ton Da Dang Sinh Hoc Dai Ven Bo Viet Nam)
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Neptunian dykes and associated features in Southern Spain: mechanics of formation and tectonic implications
No full textSustainability Assessment Of Traditional Fisheries In Cau Hai Lagoon (South China Sea).
No full textABSTRACT
Overfishing and progressive environmental degradation of the Vietnamese Cau Hai coastal lagoon appear
to be threatening the ecological integrity and water quality of the largest estuarine complex of Southeast
Asia. This study assessed the relationships between the density of traditional fisheries and organic matter
sedimentary contents in Cau Hai lagoon. Data revealed that the density of stake traps (the most common
fishing gear used in this lagoon), decreasing hydrodynamic energy in shallow water, causes the accumulation
of a large fraction of organic matter refractory to degradation. The relationship between biopolymeric
carbon (a proxy of availability of organic matter) and stake traps density fits a S-shape curve.
The logistic equation calculated a stake traps density of 90 m of net per hectare, as the threshold over
which maximum accumulation of organic matter occurs in Cau Hai. With such level of stake trap density,
and assuming a theoretical stationary status of the lagoon, the time necessary for the system to reach
hypoxic conditions has been calculated to be circa three weeks. We recommend that this density
threshold should not be exceeded in the Cau Hai lagoon and that further analyses of organic loads in the
sediment should be conducted to monitor the trophic conditions of this highly eutrophicated lagoon
Mid-Cretaceous oceanic red beds in the Umbria–Marche Basin, central Italy: Constraints on paleoceanography and paleoclimate
Full text linkDetailed studies of the mid-Cretaceous sedimentary strata in the Umbria–Marche Basin in Italy revealed that aside from severalwell-known organic-rich bblack shaleQ horizons that record OAEs, several varicolored, mainly reddish horizons indicate oxicconditions at the ocean bottom. Eight such horizons have been identified in Aptian–Cenomanian sequences in the Umbria–MarcheBasin. The dysoxic/oxic beds alternate regularly but not cyclically and seem to be the result of non-random processes. Theiroccurrence is not a completely random process. The duration of deposition of these oceanic red beds (ORBs) varies from ~ 0.13 my(ORB4) recorded in the Ticinella primula zone, to ~4.54 my for ORB1, which spans the Globigerinelloides ferreolensis zone to theTicinella bejaouaensis zone in the Piobbico core.Mid-Cretaceous ORBs are not a local phenomenon because they occur in the Tethyan deposits in the Southern and AustrianAlps, the Carpathians, the Northern Caucasus, the central North Atlantic, in northeastern England and in the western Himalayas.They provide evidence for periodic changes in redox conditions at the ocean bottom. Such changes could have been caused bychanges in bioproductivity, basin geometry, sedimentation rates, paleocirculation and/or production of bottom waters with highercontent of dissolved oxygen in response to changes in paleoclimate. We suggest that the periodic inflow of colder, moreoxygenated bottom waters was the probable cause of ORBs development, either as a result of changes in the ocean bottomtopography, or as a result of brief cool climate periods. However, reliable proxies for changes in deep ocean circulation are stilllacking. If ORBs were the result of the paleoclimate and, therefore, indirectly caused by changes in CO2 in atmosphere, theydocument the increased sensitivity and instability of the mid-Cretaceous climate. Thus, changes in ocean dynamics were on a scaleof several hundred thousand years to several million years, which has not been considered by most theories of CO2 cycling, mid-Cretaceous greenhouse paleoclimate and paleocean dynamics
Rifting, methane release, global warming and anoxia: response of a Tethyan Jurassic carbonate platform
No full textCretaceous and Paleogene boundary strata in southern Tibet and their implication for the India-Eurasia collision
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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