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| Registros recuperados: 102 | |
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| Olu, Karine; Caprais, Jean-claude; Fifis, Alexis; Fabri, Marie-claire; Galeron, Joelle; Budzinsky, H; Le Menach, K; Khripounoff, Alexis; Ondreas, Helene; Sibuet, Myriam. |
| A giant pockmark colonised by dense cold-seep assemblages near 3160 m depth along the Congo-Angola margin has been surveyed by the ROV Victor 6000. The quantitative distribution of chemosynthetic communities was mapped along the dive tracks from a video study using GIS and image mosaicking. Several types of faunal assemblages, either dominated by bivalves of the families Mytilidae (Bathmodiolus sp.) Vesicom idae (Calyptogena sp., 'Vesicomya' aff. chuni), or by Siboglinidae polychaetes (Escarpia southwardae) were mapped over the 800-m diameter pockmark area and sampled for fauna, water and sediment. The isotopic analyses (delta C-13) of tissues from symbiont-bearing species were within the range typical of nutrition via symbiosis using methane for mussels... |
| Tipo: Text |
Palavras-chave: Symbiont bearing species; Spatial distribution; Methane; Megafauna; Cold seeps. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2681.pdf |
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| Cruaud, Perrine; Vigneron, Adrien; Pignet, Patricia; Caprais, Jean-claude; Lesongeur, Francoise; Toffin, Laurent; Godfroy, Anne; Cambon-bonavita, Marie-anne. |
| In the Guaymas Basin, the presence at a few tens of kilometers of cold seeps and hydrothermal vents coupled with comparable sedimentary settings and depths offer a unique opportunity to assess and compare the microbial community composition of these deep-sea ecosystems. The microbial diversity in sediments from three cold seep and two hydrothermal vent assemblages were investigated using high-throughput 16S rRNA-sequencing. Numerous bacterial and archaeal lineages were detected in both cold seep and hydrothermal vent sediments. Various potential organic matter degraders (e.g., Chloroflexi, Atribacteria, MBG-D) and methane and sulfur cycling related microorganisms (e.g., ANME and methanogenic lineages, sulfate-reducing lineages) were detected in both... |
| Tipo: Text |
Palavras-chave: Microbial diversity; Hydrothermal vents; Cold seeps; Ribotypes; Methane; Extreme environments. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00415/52640/53496.pdf |
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| Kulivand, Mahya; Kafilzadeh, Farokh. |
| Eight different grasses collected from pastures of the Kermanshah province (Kermanshah, Iran), at mid-vegetative stage were used to study the relationships between their chemical compositions, kinetic parameters of in vitro gas production and rumen methane production. There was a positive correlation (r = 0.62, p < 0.05) between crude protein (CP) content of grasses and total gas production (A) at 96h incubation. Negative correlations were also observed between acid detergent fiber (ADF) content and total gas production (r = -0.60, p < 0.05). Amongst the nutrients, neutral detergent fiber (NDF) and ADF were positively correlated with methane concentration, (r = 0.75 and 0.77, p < 0.01). The methane reduction potential (MRP) was negative for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gas production; Pasture grasses; Methane; In vitro. |
| Ano: 2015 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/24336 |
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| Stohr, Sabine; Segonzac, Michel. |
| The animal communities associated with the deep-sea reducing environment have been studied for almost 30 years, but until now only a single species of ophiuroid, Ophioctenella acies, has been found at both hydrothermal vents and methane cold seeps. Since the faunal overlap between vent and seep communities is small and many endemic species have been found among other taxa (e.g. Mollusca, Crustacea), additional species of ophiuroids were expected at previously unstudied sites. Chemical compositions at reducing sites differ greatly from the nearby bathyal environment. Generally, species adapted to chemosynthetic environments are not found in non-chemosynthetic habitats, but occasional visitors of other bathyal species to vent and seep sites have been... |
| Tipo: Text |
Palavras-chave: Habitat description; Distribution record; Seeps; Methane; Hydrothermal vents; Ophiuroids. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-427.pdf |
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| Boulart, Cedric; Chavagnac, Valerie; Monnin, Christophe; Delacour, Adelie; Ceuleneer, Georges; Hoareau, Guilhem. |
| Serpentinisation of mantle rocks, leading to natural venting of hydrogen and methane, has been reported to occur at the global scale, wherever fluids percolate in ultramafic formations. Here we compare gas composition from two on-land, low-temperature, and hyper-alkaline springs hosted on ultramafic rocks in the ophiolite massifs of the Sultanate of Oman and the Ligurian Alps (Voltri Group, Genoa region, Northern Italy). These two settings exhibit similar chemical and mineralogical features but show diverse styles of gas venting. Commonly to all hyper-alkaline springs, gases are characterised by relatively high N-2, very low O-2 and CO2 concentrations, and a strong enrichment in H-2 and CH4. The comparison between Oman and Liguria highlights a high... |
| Tipo: Text |
Palavras-chave: Methane; Hydrogen; Gas composition; Hyper-alkaline springs. Oman; Voltri Massif. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00175/28634/27059.pdf |
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| Bréchet, Laëtitia; Courtois, Elodie A.; Saint-germain, Thomas; Janssens, Ivan A.; Asensio, Dolores; Ramirez-rojas, Irene; Soong, Jennifer L.; Van Langenhove, Leandro; Verbruggen, Erik; Stahl, Clément. |
| Tropical soils are a major contributor to the balance of greenhouse gas (GHG) fluxes in the atmosphere. Models of tropical GHG fluxes predict that both the frequency of drought events and changes in atmospheric deposition of nitrogen (N) will significantly affect dynamics of soil carbon dioxide (CO2) and methane (CH4) production and consumption. In this study, we examined the combined effect of a reduction in precipitation and an increase in nutrient availability on soil CO2 and CH4 fluxes in a primary French Guiana tropical forest. Drought conditions were simulated by intercepting precipitation falling through the forest canopy with tarpaulin roofs. Nutrient availability was manipulated through application of granular N and/or phosphorus (P) fertilizer to... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Drought; Fertilization; Methane; Nitrogen; Phosphorus; Soil GHG fluxes; Tropical forest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70694/68903.pdf |
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| Radford Knoery, Joel; German, C; Charlou, Jean-luc; Donval, Jean-pierre; Fouquet, Yves. |
| Through the deep ocean, hydrothermal plumes disperse high concentrations of key chemical tracers including He-3, CH4, Mn, Fe, H2S, etc. This paper focuses on the distribution and behavior of total dissolved sulfide (sulfide hereafter) in hydrothermal plumes to show that its plume concentration decreases to subnanomolar a few kilometers from the vents. We also report on sulfide removal rates determined at in situ conditions; we observe that they are two orders of magnitude greater than for open ocean seawater, consistent with sulfide being detected only in the vicinity of hydrothermal vents. From our observations, we infer that the sole presence of sulfide in hydrothermal plumes locates active venting at the kilometer scale. |
| Tipo: Text |
Palavras-chave: Chemical oceanography; Mid ocean ridges; Metals; Helium isotopes; Methane; Tracers; Hydrogen sulphide; Plumes; Hydrothermal activity. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-688.pdf |
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| Lazar, Cassandre Sara. |
| A large portion of the greenhouse gas methane on Earth is trapped in marine sediments. However, little methane actually reaches the hydrsphere and the atmosphere, because it is efficiently consumed by anaerobic methane-oxidizing Archaea (ANME). This methane is mainly biogenic in marine sédiments, and is produced by methanogenic Archaea. Methane ascends from deep sources to the seabed, in cold seep sites of continental margins. In order to study microbial community diversity in cold seeps, and to determine geochemical factors that control these microbial communities, we compared four geochemically and geologically distinct sites. In this work, molecular tools (PCR, RT-PCR, DGGE, cloning) as well as genetic markers (16S rRNA, mcrA, dsrB) were employed, to... |
| Tipo: Text |
Palavras-chave: Diversité moléculaire; Archaea; Méthanogène; ANME; McrA; DsrB; DGGE; Volcan de boue; Pockmark; Saumures; Fluides froids; Méthane; Mer de Norvège; Mer Méditerranée; Sédiments.; Molecular diversity; Archaea; Methanogen; ANME; McrA; DsrB; DGGE; Mud volcano; Pockmark; Brines; Cold seep; Methane; Norwegian Sea; Mediterranean Sea; Sediments.. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00031/14250/11534.pdf |
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| Osorio-Teran,Amada Isabel; Mendoza-Martínez,Germán David; Miranda-Romero,Luis Alberto; Martínez-Gomez,Daniel; Hernández-García,Pedro Abel; Martínez-García,José Antonio. |
| ABSTRACT An evaluation of the effects of monensin and calcium propionate on the in vitro kinetics of gas production, digestibility, carbon dioxide, and minor gas production on different days was performed using the ruminal fluid from eight Suffolk lamb donors, after receiving additives for 1, 10, and 20 days. Treatments consisted of a control ration of 40% grain; 30 mg/kg of monensin in a diet with 40% grain; 10 g/kg calcium propionate in a diet with 30% grain; and the combination of both additives in a diet with 30% grain. The gas production was measured up to 72 h of incubation and all incubation procedures were repeated three times on days 1, 10, and 20. On incubation day 20, the volume and production of methane and minor gases were measured. There was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Additive feeding; Carbon dioxide; Ionophore; Methane; Rumen fermentation. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000400348 |
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| Castillo Rangel,Francisco; Villalobos Villalobos,Guillermo; Domínguez Díaz,David; Ortega Gutiérrez,Juan Ángel. |
| ABSTRACT The objective was to evaluate the effect of three levels of cull pinto beans (CPB; Phaseolus vulgaris) on ruminal fermentation, kinetics, and nutrient digestibility in hair lambs. Six cannulated lambs averaging 56.6±3.8 kg were used and were randomly assigned to one of three treatments. Treatments were: 0.0 kg kg−1 of CPB in the supplement (control); 0.25 kg kg−1 of CPB in the supplement (CB25); and 0.40 kg kg−1 of CPB in the supplement (CB40). Dry matter intake, ruminal pH, NH3, and volatile fatty acid (VFA) concentration, methane production, Kp (passage rate), MRT (mean retention time), and digestibility of dry matter, crude protein, and neutral detergent fiber were evaluated. Data were analyzed in a Latin square design, repeated in line, by... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonia; Legumes; Methane; Ruminal pH; Sheep; Volatile fatty acids. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000500405 |
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| Chiemchaisri,Wilai; Visvanathan,Chettiyappan; Jy,Shing Wu. |
| The effects of volatile organic compounds (VOCs) on methane oxidation in landfill cover soils were examined. The batch experiments were conducted using single and mixed VOCs, such as, dichloromethane (DCM), trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. The results from all combinations showed a decrease in methane oxidation rate with increase in VOC concentrations. Moreover, inhibition effects of TCE and DCM were found higher than benzene and PCE. The reduction of methane oxidation by benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cells internal membrane was found in a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Landfill cover soils; Methane; Methanotrophs; Methane oxidation; Volatile organic compounds (VOCs). |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000200005 |
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| ROGERIO, M. C. P.; BORGES, I.; FERREIRA, A. L.; MACHADO, F. S.; POMPEU, R. C. F. F.; GUEDES, L. F.; COSTA, C. dos S.; GUEDES, F. L.; GALVANI, D. B.. |
| Resumo: A respirometria em ensaios com pequenos ruminantes contribui para a mensuração das emissões de gases de efeito estufa (GEE), subsídio ao pagamento por serviços ambientais e para o desenvolvimento de rações e suplementos que propiciem a máxima eficiência alimentar. Para as aferições de emissão de GEE, 15 cordeiras Santa Inês, com peso de 15,09 kg±2,63 kg, foram avaliadas na câmara respirométrica do Laboratório de Respirometria do Semiárido (Laresa) da Embrapa Caprinos e Ovinos. As dietas foram for-muladas conforme as exigências nutricionais descritas pelo NRC (National Research Council, 2007), em planos nutricionais para manutenção, acaba-mento de carcaça precoce e de carcaça tardia, com cinco repetições. As taxas médias de recuperação para CO2 e... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Gás carbônico; Energia líquida; Semiárido; Metabolismo nutricional; Caloric increment; Liquid energy; Caprino; Ovino; Incremento Calórico; Metano; Goats; Sheep; Carbon dioxide; Methane; Brazil. |
| Ano: 2019 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1117071 |
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| Registros recuperados: 102 | |
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