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| Registros recuperados: 51 | |
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| Vargas,Gustavo; Donoso-Bravo,Andrés; Vergara,Christian; Ruiz-Filippi,Gonzalo. |
| Background: Industrial wastewaters with a high content of nitrogen are a relevant environmental problem. Currently, treatments to remove nitrogen are not efficient, so is necessary to develop alternative methods. The objective of this study is to investigate a consortium of microalgae - nitrifying, that due to the symbiosis between them could be an interesting alternative. Results: In this study, it was possible to obtain a consortium of nitrifying bacteria (NB) and microalgae (MA) capable of operating with low requirements of dissolved oxygen, using aerobic sludge from wastewater treatment plants. During the operation, this consortium presents removal percentages above 98% of ammonia, even at concentrations of DO of 0.5 mg O2 L-1. It is estimated that the... |
| Tipo: Journal article |
Palavras-chave: Ammonium; Consortium nitrifying-microalgae; Oxygen; Respirometry. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000500007 |
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| Vale,Marcos M. do; Moura,Daniella J. de; Nääs,Irenilza de A.; Curi,Thayla M. R. C.; Lima,Karla A. O.. |
| ABSTRACT Global warming increases the occurrence of events such as extreme heat waves. Research on thermal and air conditions affecting broiler-rearing environment are important to evaluate the animal welfare under extreme heat aiming mitigation measures. This study aimed at evaluating the effect of a simulated heat wave, in a climatic chamber, on the thermal and air environment of 42-day-old broilers. One hundred and sixty broilers were housed and reared for 42 days in a climatic chamber; the animals were divided into eight pens. Heat wave simulation was performed on the 42nd day, the period of great impact and data sampling. The analyzed variables were room and litter temperatures, relative humidity, concentrations of oxygen, carbon monoxide and ammonia... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonia; Gas production; Animal welfare; Oxygen; Litter temperature. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000200271 |
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| Chapelle, Annie; Menesguen, Alain; Deslous-paoli, Jean-marc; Souchu, Philippe; Mazouni, Nabila; Vaquer, André; Millet, Bertrand. |
| An ecosystem model based on nitrogen cycling and oxygen has been developed for the Thau lagoon. It takes into account the specific features of this Mediterranean lagoon, a semi-confined system with watershed inputs and oyster farming. The ecosystem model uses currents calculated by a two-dimensional hydrodynamic model and integrated into a box model. This model is compared with a year survey data and used to estimate nitrogen and oxygen fluxes between the different ecosystem compartments. The yearly simulation shows that the ecosystem behavior is driven by meteorological forcing, especially rain which causes watershed inputs. These inputs trigger microphytoplankton growth, which is responsible for new primary production. During dry periods, nitrogen is... |
| Tipo: Text |
Palavras-chave: Oxygen; Nitrogen; Oysters; Primary production; Box model; Lagoon ecosystem. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-725.pdf |
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| Darnaude, Audrey M.; Hunter, Ewan. |
| The oxygen isotopic ratio of fish otoliths is increasingly used as a 'natural tag' to assess provenance in migratory species, with the assumption that variations in delta O-18 values closely reflect individual ambient experience of temperature and/or salinity. We employed archival tag data and otoliths collected from a shelf-scale study of the spatial dynamics of North Sea plaice Pleuronectes platessa L., to examine the limits of otolith delta O-18-based geolocation of fish during their annual migrations. Detailed intra-annual otolith delta O-18 measurements for 1997-1999 from individuals of 3 distinct sub-stocks with different spawning locations were compared with delta O-18 values predicted at the monthly, seasonal and annual scales, using predicted... |
| Tipo: Text |
Palavras-chave: Fish migration; Oxygen; Stable isotopes; Natural tag; Site fidelity; Plaice; Pleuronectes platessa. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00626/73782/75084.pdf |
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| Mazouni, Nabila; Deslous-paoli, Jean-marc; Landrein, Sonia. |
| The impact of suspended oyster culture (Crassostrea gigas, Thunberg) on oxygen and nutrient fluxes has been studied in situ, in a coastal lagoon (Thau, France), during a seasonal cycle. On the first plan of the multiple factorial correspondences analysis (MCA), seasons were well discriminated. The fluxes were maximum in summer and minimum in winter. However, this seasonal pattern was not only linked to the water temperature, as autumn and spring (similar temperatures of about 12 degrees C) were distinct in the second factorial plan (2.3). Oxygen uptake by the oyster cultures varied between 0 mu mol m(-2) h(-1) (January) and 11 823 +/- 377 mu mol m(-2) h(-1) (July). Ammonia and nitrate-nitrites were released into the water column respectively at a rate of... |
| Tipo: Text |
Palavras-chave: Oxygen; Nutrients; Fluxes; Oyster culture; Oxygène; Nutriments; Flux; Elevage ostréicole. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-840.pdf |
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| Khalil, Karima; Raimonet, Melanie; Laverman, Anniet M.; Yan, Chen; Andrieux-loyer, Françoise; Viollier, Eric; Deflandre, Bruno; Ragueneau, Olivier; Rabouille, Christophe. |
| This paper deals with the spatial and seasonal recycling of organic matter in sediments of two temperate small estuaries (Elorn and Aulne, France). The spatio-temporal distribution of oxygen, nutrient and metal concentrations as well as the organic carbon and nitrogen contents in surficial sediments were determined and diffusive oxygen fluxes were calculated. In order to assess the source of organic carbon (OC) in the two estuaries, the isotopic composition of carbon (δ 13C) was also measured. The temporal variation of organic matter recycling was studied during four seasons in order to understand the driving forces of sediment mineralization and storage in these temperate estuaries. Low spatial variability of vertical profiles of oxygen, nutrient, and... |
| Tipo: Text |
Palavras-chave: Spatial and temporal variability; Estuarine sediment; Oxygen; Organic carbon and isotopic composition; Microelectrode; Organic matter recycling. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00164/27533/25691.pdf |
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| Claireaux, Guy; Webber, D; Lagardere, Jean-paul; Kerr, S. |
| Environmental influences (temperature and oxygenation) on cod metabolism and their impact on the ecology of this species were investigated. Limiting oxygen concentration curves (O-2 level ranging between 15 and 100% air saturation) were established at 2, 5 and 10 degreesC. The standard metabolic rate (SMR), the maximum metabolic rate and the metabolic score were then modelled as functions of temperature and/or oxygen saturation. The mean SMR at 2, 5 and 10 degreesC were 19.8 +/- 4.9, 30.8 +/- 6.1 and 54.3 +/- 4.1 mg O-2 h(-1) kg(-1). respectively. Between 2 and 5 degreesC, the active metabolic rate of cod almost doubled from 65 to 120 mg O-2 h(-1) kg(-1), to reach 177 mg O-2 h(-1) kg(-1) at 10 degreesC. In terms of metabolic scope (MS), the temperature... |
| Tipo: Text |
Palavras-chave: Oxygen; Temperature; Physiological ecology; Metabolism; Atlantic cod. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-428.pdf |
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| Bittig, Henry; Kortzinger, Arne; Johnson, Ken; Claustre, Hervé; Emerson, Steve; Fennel, Katja; Garcia, Hernan; Gilbert, Denis; Gruber, Nicolas; Kang, Dong-jin; Naqvi, Wajih; Prakash, Satya; Riser, Steven; Thierry, Virginie; Tilbrook, Bronte; Uchida, Hiroshi; Ulloa, Osvaldo; Xing, Xiagang. |
| Recommendation for Oxygen Measurements from Argo Floats: Implementation of In-Air-Measurement Routine to Assure Highest Long-term Accuracy As Argo has entered its second decade and chemical/biological sensor technology is improving constantly, the marine biogeochemistry community is starting to embrace the successful Argo float program. An augmentation of the global float observatory, however, has to follow rather stringent constraints regarding sensor characteristics as well as data processing and quality control routines. Owing to the fairly advanced state of oxygen sensor technology and the high scientific value of oceanic oxygen measurements (Gruber et al., 2010), an expansion of the Argo core mission to routine oxygen measurements is perhaps the most... |
| Tipo: Text |
Palavras-chave: Argo; Bio-argo; Oxygen. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00348/45917/46180.pdf |
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| Koc, N; Labeyrie, L; Manthe, S; Flower, Bp; Hodell, Da; Aksu, A. |
| Well-preserved diatoms are present in high sedimentation rate Pleistocene cores retrieved on ocean Drilling Program (ODP) Legs 151, 152, 162 and IMAGES cruises of RN Marion Dufresne from the North Atlantic. Investigation of the stratigraphic occurrence of diatom species shows that the youngest diatom event observed in the area is the last occurrence (LO) of Proboscia curvirostris (Jouse) Jordan and Priddle. P. curvirostris is a robust species that can easily be identified in the sediments, and therefore can be a practical biostratigraphic tool. We have mapped its: areal distribution, and found that it stretches from 40 degreesN to 80 degreesN in the North Atlantic. Further, we have correlated the LO P. curvirostris to the oxygen isotope records of six... |
| Tipo: Text |
Palavras-chave: Biostratigraphy; North Atlantic; Diatoms; Pleistocene; Paleoceanography; Isotope stratigraphy; Oxygen. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33210/31708.pdf |
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| Payne, Jonathan L.; Groves, John R.; Jost, Adam B.; Thienan Nguyen,; Moffitt, Sarah E.; Hill, Tessa M.; Skotheim, Jan M.. |
| Atmospheric hyperoxia, with pO2 in excess of 30%, has long been hypothesized to account for late Paleozoic (360250 million years ago) gigantism in numerous higher taxa. However, this hypothesis has not been evaluated statistically because comprehensive size data have not been compiled previously at sufficient temporal resolution to permit quantitative analysis. In this study, we test the hyperoxia-gigantism hypothesis by examining the fossil record of fusulinoidean foraminifers, a dramatic example of protistan gigantism with some individuals exceeding 10 cm in length and exceeding their relatives by six orders of magnitude in biovolume. We assembled and examined comprehensive regional and global, species-level datasets containing 270 and 1823 species,... |
| Tipo: Text |
Palavras-chave: Body size; Carboniferous; Cope's Rule; Foraminifera; Oxygen; Permian. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00265/37626/35865.pdf |
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| Maurice, Laurence. |
| The main problem of the Girond estuary is a pollution by the cadmium. During this last ten years, the good quality of the water is proved by the analysis of the main physico - chemical and biochemical parameters and bacteria. But since 1989, straight to the Blayais power station, the BOD5 varied between 2 and 3,5 mg.l-1 and a diminution of the dissolved oxygen has been observed; it's probably caused by the accumulation of biodegradable organic matter in the maximum turbidity zone during years characterized by low river flows. For average river flow, urban discharges takes part for 20 % in total fluxes of BD05; in 1991, this part attempts 35 %. During the last 7 years, the pluriannual evolution of the nitrate concentrations measured in the Garonne river... |
| Tipo: Text |
Palavras-chave: Oxygène; Sels nutritifs; Matière organique; Bactéries; Apports; Estuaire Gironde; Oxygen; Nutrients; Organic matter; Bacteria; Fluxes; Gironde estuary. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00037/14855/12178.pdf |
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| Stanisiere, Jean-yves; Mazurie, Joseph; Bouget, Jean-francois; Langlade, Aime; Gabellec, Raoul; Retho, Michael; Quinsat, Kevin; Leclerc, Emilie; Cugier, Philippe; Dussauze, Morgan; Menesguen, Alain; Dumas, Franck; Gohin, Francis; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Goubert, Evelyne; Dreano, Alain. |
| The project “Risco”, supported by the “Pôle Mer” and funded by the Regional Council of Brittany, deals with specific risks of mortality of oysters, Crassostrea gigas, cultivated on the bottom, in a subtidal bay of South Brittany : the bay of Quiberon (56, France). Massive mortalities of oysters were reported in summer 2006 in this bay, exclusively located in the deep muddy area with a positive gradient eastward. A validated biogeochemical model was applied in order to simulate the dissolved oxygen over 2000-2006 : it revealed several episodes of hypoxia, more or less intense according to years, but with the same spatial distribution. This approach proved 2006 to be the most hypoxic year since 2000. The hypoxia was due to a rare conjunction of 3 factors :... |
| Tipo: Text |
Palavras-chave: Baie Quiberon; Crassostrea gigas; Huître; Mortalité; Croissance; Hypoxie; Oxygène; Modèle; Upwelling; Loire; Vilaine; Quiberon; Crassostrea gigas; Oyster; Mortality; Growth; Hypoxia; Oxygen; Model; DEB; Upwelling; Loire; Vilaine. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29131/27535.pdf |
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| Christensen, Jp. |
| A diagenetic model of porewater O-2 was used to examine the relationship between organic carbon flux to the sediments and benthic oxygen demand (BOD). The model predicted that the organic carbon influx to sediments balances BOD as long as sediments are oxygenated. The critical rate occurs when O-2 at infinite depth disappears. With influxes exceeding the critical rate, the O-2 flux into the sediments via molecular diffusion can not consume all incoming organic matter, and anaerobic conditions result in BOD underestimating the carbon influx. Given that low rates of deep-sea BOD approximate the carbon influx below 9 g.C.m(-2).y(-1), a significant multilinear regression was found between published BOD, primary productivity (P-p, both in g.C.m(-2).y(-1))(,)... |
| Tipo: Text |
Palavras-chave: Fonds marins; Oxygène; Production primaire; Respiration; Sédiments; Deep-sea; Oxygen; Primary productivity; Respiration; Sediments. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00325/43578/44046.pdf |
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| Registros recuperados: 51 | |
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