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| Registros recuperados: 95 | |
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| Bouchet, Vincent; Debenay, Vincent; Sauriau, Pierre-guy; Radford Knoery, Joel; Soletchnik, Patrick. |
| Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. Foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic... |
| Tipo: Text |
Palavras-chave: Marennes Oléron bay; Aquaculture; Crassostrea gigas; Intertidal; Ammonium; Hypoxia; Organic matter; Living benthic foraminifera. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2586.pdf |
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| Abdalla,Asim M; Tingari,M. D; Ali,K. Z; Rezigalla,A. A; Al-shraim,Mubarak; Eid,Refaat, A. |
| The study was carried out at two different altitudes in the southern region of Saudi Arabia: Abha, 2,800 meters above sea level, the high altitude (HA) area and Jazan, 40 meters above sea level the low altitude (LA) area. Following exposure to high altitude, testes of rats revealed various types of atrophy and degeneration in the seminiferous tubules and in the interstitial tissue. There was detachment of the basal laminae of the tubules and a profound decrease in cellularity. When rats were brought back to their habitat (LA) and later examined, many tubules showed normal population of cells including spermatids and spermatozoa. Well-arranged epithelium was seen in most of the seminiferous tubules of these animals, normal interstitial space and no... |
| Tipo: Journal article |
Palavras-chave: High altitude; Low altitude; Hypoxia; Semen; Reproductive hormones. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022016000100023 |
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| Pellón,Mario; Rojas,Mariana; Saint-Pierre,Gustavo; Hartley,Ricardo; del Sol,Mariano. |
| It has been demonstrated that hypoxia retards the growth of fish, reduces the survival of their larvae, deforms their vertebral column, but despite this teleost fish have the ability to completely regenerate many of their tissues, particularly the retina. As we do not have enough information about the effects of hypoxia on the eyeball, orbit and retina of Atlantic salmon (Salmo salar), we propose the following objectives: 1) Compare the morphological changes of the eyeball of fish subject to hypoxia and normoxia. 2) Determine changes in the orbit structure. 3) Describe the retina of salmon alevins. 4). Recognize hypoxic cells using the anti-Hif1a antibody in the retina of alevins as a sensor. 5) Determine the Shh morphogenic expression in alevins exposed... |
| Tipo: Journal article |
Palavras-chave: Eyeball; Orbit; Retina; Salmo salar; Hypoxia; HIF1a; Shh. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022016000100046 |
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| Bustos-Obregón,Eduardo; Esveile,Christian; Contreras,Julio; Maurer,Inge; Sarabia,Luis. |
| Reduction of O2 delivery to tissues damage them, including the seminiferous epithelium. Recently, population working in high altitude has increased, so that the study of hypobaric hypoxia on spermatogenesis becomes of interest. In this study we used two groups of male, sexually mature mice Control (C) (540 meters above sea level (masl)) and chronic simulated hypobaric hypoxia (CSHH) (4,600 masl) exposed during 8, 16, 24 or 33 days. Hematocrit; reticulocytosis; testicular, epididymal and seminal vesicle weight; seminiferous epithelium height, tubular diameter, sperm count and morphology and testicular parenchyme and spermatozoa membranes lipoperoxidation were measured. Weight of testis, epididymis and seminal vesicle were reduced but they recuperate at 33... |
| Tipo: Journal article |
Palavras-chave: Hypoxia; Lipoperoxidation; Mouse; Testis. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000400030 |
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| Castro Sánchez,Rodrigo; Bustos Obregón,Eduardo; Rojas Rauco,Mariana. |
| Vertebral Column Deformity (VCD) is a common pathology in Chilean salmon farms, lowering the quality and commercialization of the product. Hypoxia has been related to other musculoskeletal deformities, but not to VCD. This work analyzes the morphology of the vertebral column of Salmo salar alevins, cultured under hypoxic conditions (60% O2 saturation in the water tanks) for different time periods after hatching (2, 4, 6 and 8 days). They are compared with their normoxic controls (100% O2 saturation). Using histological (H/E), and morphometric techniques, it was found that the time of exposure to hypoxia is inversely proportional to the body length, notochordal diameter and thickness of its sheath. The organic response to hypoxia was quantified by... |
| Tipo: Journal article |
Palavras-chave: Vertebral Column; Deformity; Hypoxia; Salmon. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000400036 |
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| Mohammed,Heitham Mutwakil; Tingari,M. D. |
| The study was carried out at two different altitudes in the southern region of Saudi Arabia: Abha, 2,800 meters above sea level, the high altitude (HA) area and Jazan, 40 meters above sea level the low altitude (LA) area. Following exposure to high altitude, and up to the third week of postnatal development, some of the seminiferous tubules showed detachment from the basal lamina, spaces of different sizes within the epithelial layer with vacuoles in the center and Pyknotic nuclei were noted in the spermatogonia and primordial germ cells. Rounded spermatids were seen in the lumen only on day 35 of hypoxic group, no spermatozoa were recognized until day 45 of postnatal development. On day 45 hypoxic rat testes revealed various types of atrophy and... |
| Tipo: Journal article |
Palavras-chave: High altitude; Low altitude; Hypoxia. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022016000200031 |
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| Pompeu,Paulo dos Santos; Godinho,Hugo Pereira. |
| In the Neotropics, a large proportion of fish communities of large rivers use floodplain as habitats for feeding, reproduction, and refuge. An evaluation was made of the effects of extended dry periods on the species richness, abundance and local extinction of fish species in three marginal lagoons in the middle São Francisco River, southeastern Brazil. The studied lagoons fail to receive river floods during the study period (1994-1996). A gradual reduction in richness and abundance was observed in all lagoons. Migratory fish species had the highest probability to become extinct in the two lagoons that remained with large water volume. Species tolerant to low levels of dissolved oxygen had the lowest probability of local extinction in the lagoon showing an... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Floodplain; Migratory fish; Extended drought; Hypoxia. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000400006 |
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| Souza,Thiago Corrêa de; Magalhães,Paulo César; Pereira,Fabrício José; Castro,Evaristo Mauro de; Silva Junior,Jessé Marques da; Parentoni,Sidney Neto. |
| The objective of this work was to assess the effect of successive selection cycles on leaf plasticity of 'Saracura' maize BRS-4154 under periodical flooding in field conditions. Soil flooding started at the six-leaf stage with the application of a 20-cm depth water layer three times a week. At flowering, samples of leaves were collected and fixed. Paradermic and transverse sections were observed under photonic microscope. Several changes were observed throughout the selection cycles, such as modifications in the number and size of the stomata, higher amount of vascular bundles and the resulting decrease of the distance between them, smaller diameter of the metaxylem, decrease of cuticle and epidermis thickness, decrease of number and size of bulliform... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Hypoxia; Leaf anatomy; Tolerance to flooding. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2010000100003 |
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| MARCHEZAN,M.G.; AVILA,L.A.; AGOSTINETTO,D.; SCHAEDLER,C.E.; LANGARO,A.C.; OLIVEIRA,C.; ZIMMER,M.; SCHREIBER,F.. |
| ABSTRACT Herbicide selectivity in paddy rice varies in several aspects, among which are the environmental conditions. The aim of the study was to evaluate the effect of herbicide application and total plant submersion on morphological and biochemical changes in paddy rice. Total chlorophyll and carotenoids, catalase activity, ascorbate peroxidase and superoxide dismutase, total phenolic content, lipid peroxidation and hydrogen peroxide levels were assessed. Leaf samples were collected 24 hours and 7 days after the application of water regimes. The results observed in the first experiment show that cultivars Puitá INTA CL, IRGA 417 and IRGA 422 CL are more tolerant to total submersion. The most sensitive cultivars are IRGA 424, BRS Querência, EPAGRI 108 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oxidative stress; Hypoxia; Oryza sativa; Herbicide selectivity. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582017000100201 |
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| Petrolia, Daniel R.; Gowda, Prasanna H.. |
| Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural subsurface tile drainage is a major carrier of nitrogen from croplands to streams and rivers. This study compares the results of abating nitrogen under a retired-land minimization policy with those of a new revenue-maximizing policy, paying particular attention to the role of tile-drained land. Findings reveal the retirement-minimizing policy resulted in more tile-drained land being retired and less being fertilizer-managed than was optimal under the net-return maximizing policy. Also, it led to a greater economic burden being shouldered by tile-drained land. Under both cases, tile drainage dominated the abatement process. |
| Tipo: Journal Article |
Palavras-chave: Abatement; ADAPT; Drainage; Hypoxia; Nitrogen; Crop Production/Industries; Land Economics/Use. |
| Ano: 2006 |
URL: http://purl.umn.edu/8621 |
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| Petrolia, Daniel R.; Gowda, Prasanna H.; Mulla, David J.. |
| Agricultural nitrogen losses are the major contributor to nitrogen loads in the Mississippi River, and consequently, to the existence of a hypoxic, or "dead", zone in the Gulf of Mexico. Focusing on two small agricultural watersheds in southwestern Minnesota, simulation results from the Agricultural Drainage And Pesticide Management (ADAPT) model were combined with a linear-optimization model to evaluate the environmental and economic impact of alternative land-use policies for reducing nitrogen losses. Of particular importance was the study's explicit focus on agricultural subsurface (tile) drainage, which has been identified as the major pathway for agricultural nitrogen losses in the upper Midwest, and the use of drainage-focused abatement policies.... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Drainage; Hypoxia; ADAPT; Nitrogen; Watershed; Environmental Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/19416 |
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| ANDRADE,ANTÔNIO CARLOS SILVA DE; RAMOS,FLAVIO NUNES; SOUZA,ALEXANDRE FADIGAS DE; LOUREIRO,MARTA BRUNO; BASTOS,RODRIGO. |
| Six-month-old seedlings of Cytharexyllum myrianthum and Genipa americana, two common tree species in different flood-prone areas in Brazil, were flooded for up to 90 days to compare their survival and growth responses under these conditions. Seedlings of both species were found to be relatively tolerant to flooding but growth responses changed according to treatment and plant species. Growth of G. americana was reduced by flooding, showing a decrease in root and leaf dry mass, root/shoot ratio and height, without showing any adaptive morphological changes. On the other hand, growth of C. myrianthum seedlings was stimulated under flooding conditions, showing an increase in root dry mass, root/shoot ratio, height, stem diameter and some morphological changes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anaerobiosis; Environmental stress; Growth; Hypoxia; Submergence. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041999000500009 |
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| KOLB,ROSANA M.; MEDRI,MOACYR E.; BIANCHINI,EDMILSON; PIMENTA,JOSÉ A.; GILONI,PATRICIA C.; CORREA,GERALDO T.. |
| Em matas ciliares da Bacia Hidrográfica do Rio Tibagi, nas áreas sujeitas a inundações periódicas, é comum a ocorrência de S. commersoniana onde, geralmente, se torna a espécie dominante. A fim de elucidar alguns aspectos de tolerância ao alagamento, plantas dessa espécie foram mantidas na capacidade de campo e em solo alagado por dois meses. Após esse período, algumas plantas foram desalagadas para verificar o comportamento da espécie no período de reaeração. O alagamento induziu, em raízes, aumento de espaços intercelulares, redução na espessura do cilindro central e aumento na espessura do córtex. Plantas alagadas cresceram menos que as controle e desenvolveram lenticelas hipertróficas caulinares e algumas raízes adventícias. Plantas reaeradas retomaram... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ecological anatomy; Hypoxia; Sebastiania commersoniana. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041998000300010 |
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| Leite,Fernando Palha; Novais,Roberto Ferreira; Silva,Ivo Ribeiro; Barros,Nairam Félix; Neves,Júlio César Lima; Medeiros,Alex Giovanny B.; Ventrella,Marília Contin; Villani,Ecila Mercês de Albuquerque. |
| Eucalyptus Shoot Blight in the Vale do Rio Doce (ESBVRD) is an anomaly that leads to reduced growth and, in more extreme cases, to death of eucalyptus plants. Initially diagnosed in plantations in the region of the Vale do Rio Doce, in the State of Minas Gerais, Brazil, this problem has also been found in plantations in other regions of the country and even in other countries. Although the symptoms of this anomaly are well-known, its causes are not yet understood. The aim of this study was to evaluate the cause-effect relationship between accumulation of manganese (Mn) in eucalyptus clones and ESBVRD. Characterization of the environment in areas of greater occurrence of this problem in regard to soil, climate and fluctuation of the water table was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hypoxia; Groundwater; Redox potential. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000100019 |
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| Registros recuperados: 95 | |
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