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381.
Amado LL da Rosa CE Leite AM Moraes L Pires WV Pinho GL Martins CM Robaldo RB Nery LE Monserrat JM Bianchini A Martinez PE Geracitano LA 《Marine pollution bulletin》2006,52(2):199-206
Biomarkers of exposure and effect of pollutants were analyzed in croakers Micropogonias furnieri (Teleostei: Sciaenidae) captured in winter and summer in a polluted and in a non-polluted site at the Patos Lagoon estuary (Southern Brazil). Catalase and glutathione S-transferase activities (exposure biomarkers) and lipid peroxidation (effect biomarker) were analyzed in liver samples. Other two effect biomarkers were also studied: blood cells DNA damage (through comet assay and micronucleus test) and respiratory burst measurements. In a broad view, results point to an important seasonal variation of the biochemical biomarkers analyzed. However, data obtained clearly indicate that croakers collected in winter at the polluted site were subjected to a level of clastogenic agents sufficient to generate irreversible genetic damages (mutations) and impair the fish immune system. 相似文献
382.
The first morphotectonic model of the Greater Antilles is presented. The model is adjusted to the current dynamics between the Caribbean and North American plates. It is mainly elaborated by Rantsman’s methodology. We determined 2 megablocks, 7 macroblocks, 42 mesoblocks, 653 microblocks and 1264 nanoblocks. They constitute a set of active blocks under rotation, uplifting and tilting movements. A total of 11 active knots of faults and 8 cells are the main articulation areas. The largest seismogenetic structures in the Northern Caribbean are an array of the active fault segments. The majority of them are in the Caribbean-North American Plate Boundary Zone, the Hispaniola has the most complex neotectonic structure–associated with the central axis of the morphotectonic deformations in the region. 相似文献
383.
Older people are arguably one of the most vulnerable groups during a disaster. Existing studies either in China or in other countries predominantly focus on the more Western, pathology-based mental health approach in addressing the impact of disasters on older victims and their needs. However, the concept of ‘psychosocial’ recognises that problems caused by emergencies can simultaneously be of a social nature and a psychological one. This concept emerged from a growing critique on individual oriented mental health approach in disaster contexts. The present study was conducted to explore older people’s needs from a psychosocial perspective. The research site was a Chinese rural community located in the epicentre of ‘5.12’ Wenchuan earthquake (Ms = 8.0) occurred in 2008. The authors conducted content analyses on the qualitative in-depth interviews with 10 (5 males and 5 females) out of 30 older persons from this community. The findings revealed three major psychosocial problems: (1) constant fear of recurring debris flows; (2) sense of helplessness; and (3) disruption to previous social network. Indubitably, the participants reported family members and neighbours as their major sources of social support in emergency situations. This exploratory study argues that older people being exposed to disasters will not only develop psychological problems but also suffer disruption to their social support network and puts forward that empowering family and strengthening community cohesion are important initiatives for helping professionals to promote older people’s psychosocial well-being and enhance their resilience to natural disasters. 相似文献
384.
L. A. Sim L. M. Bogomolov O. A. Kuchai A. A. Tataurova 《Russian Journal of Pacific Geology》2017,11(3):223-235
Tectonophysical studies are conducted in South Sakhalin for identification of temporal–spatial changes in the geodynamic settings of the formation of the local structures. Analysis of the field data reveals 11 local stress state (LSS) in the large newest megastructures, which were formed on geological basement of different ages. The parameters of the tectonic stresses are significantly distinct in each LSS, especially the orientations (up to reindexation) of the compression and extension axes in different fault wings. Tectonic stresses of two ages and constant latitudinal and horizontal compression axis are reconstructed. The earlier cofold shear stress field with a horizontal and longitudinal extension axis is post-Miocene and the later stress field of the reversed fault with a vertical extension axis is orogenic. The LSSs reconstructed for the first time by the displacement vectors on slickensides, along with the data on the earthquake mechanisms, substantiate the reindexation of the horizontal extension axis with the vertical intermediate axis of major normal stresses at the postfold orogenic stage of evolution of the territory. These results are in agreement with previous data on the transformation of the dextral to reverse thrust displacements along the longitudinal fault systems. The young stress field is more confidently interpreted in the activation fault zones, which limit the orogenic blocks, whereas the traces of cofold deformations without younger orogenic stress fields better remain inside the blocks which are composed of older and strongly dislocated Mesozoic rocks. 相似文献
385.
Spatial distribution and estimation of rainfall trends and erosivity in the Epitácio Pessoa reservoir catchment,Paraíba,Brazil 总被引:1,自引:0,他引:1
da Silva Richarde Marques Santos Celso Augusto Guimarães da Costa Silva Jorge Flávio Cazé Braga Silva Alexandro Medeiros Brasil Neto Reginaldo Moura 《Natural Hazards》2020,102(3):829-849
Natural Hazards - The main goals of this study are to better understand the spatial and temporal variabilities in rainfall and to identify rainfall trends and erosivity for the period from 1963 to... 相似文献
386.
Pedro Walfir M. Souza-Filho Roberto Vizeu L. Pinheiro Francisco R. Costa José Tasso F. Guimarães Prafulla K. Sahoo Marcio S. Silva Cleverson G. Silva 《地球表面变化过程与地形》2020,45(14):3732-3746
This work details the role of fault reactivation in the development of tropical montane lakes by using basin morpho-structural analysis and seismostratigraphic studies. The upland lakes are severely faulted sinkholes, whose faults penetrate the Quaternary sedimentary units. Four main stages are related to the lake formation: (i) an Early Proterozoic tectonic deformation of the rocks along the southern border of the Carajás Structure, where the lake is placed; (ii) differential erosion by – and building of – the formation of the South Carajás Hill; (iii) Fe-rich crust formation by weathering and gravitational collapse faults following the E–W plateau border and the start of Violão Lake formation during the Pliocene–Pleistocene; and (iv) episodic fault-fracture reactivation by gravitational collapse causing pulses of subsidence in the lake and outlining its faulted borders. Dissolution of the lateritic crust and erosion by runoff drainage under wet climate conditions were coeval with fault activities, which allowed the deposition of relatively thick clastic deposits organized in three main seismostratigraphic units associated with major lake-level fluctuations. Initial fault reactivation under low-level water started lacustrine basin development with deposition of prograding fan deltas related to the main drainage. A second fault reactivation by gravitational collapse increased the lake accommodation space and resulted in the deposition of fine-grained sediments from dilute interflows or overflows until 36 000 cal year BP. At about 31 000 cal year BP, rapid decreases in the lake water level under redox conditions at the sediment/water interface allowed widespread siderite formation. A third gravitational collapse episode was responsible for the increase in the lake area and depth and the returning of clastic/organic deposition up to the present. This tropical montane lake can be seen as a representative example for understanding the formation of other upland lakes controlled by fault reactivation. © 2020 John Wiley & Sons, Ltd. 相似文献