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| Registros recuperados: 309 | |
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| Boulais, Myrina; Suquet, Marc; Arsenault-pernet, Marie Eve Julie; Malo, Florent; Queau, Isabelle; Pignet, Patricia; Ratiskol, Dominique; Le Grand, Jacqueline; Huber, Matthias; Cosson, Jacky. |
| Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions) and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster. The acidic pH of the gonad (5.82 ± 0.22) maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe) when released in seawater (SW). At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi) of spermatozoa, compared... |
| Tipo: Text |
Palavras-chave: Seminal fluid; Spermatozoa; Motility; PH; Salinity; Ions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53976/55137.pdf |
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| Gales, Amandine; Triplet, Sebastien; Geoffroy, Thibault; Roques, Cécile; Carre, Claire; Le Floc'H, Emilie; Lanfranchi, Mélissa; Simier, Monique; Roque D'Orbcastel, Emmanuelle; Przybyla, Cyrille; Fouilland, Eric. |
| Recently, CO2 recycling for the production of valuable microalgae has acquired substantial interest. Most studies investigating CO2 conversion efficiency in algal cultures were based on single species, although a stabilising effect of algal diversity on biomass production was recently highlighted. However, addition of CO2 into polyalgal cultures requires a careful control of pH; performance of CO2 conversion, growth and carbon biomass production are affected by pH differently, depending on the species of microalgae. This study investigates the efficiency of CO2 conversion by natural marine algal assemblage cultivated in open, land-based raceways (4.5 m3, 10 m2), working as high rate algal ponds (HRAP). Ponds were enriched with nitrogen and phosphate, pure... |
| Tipo: Text |
Palavras-chave: Carbon yield; Microalgal diversity; PH; Predators. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72403/71392.pdf |
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| Hussenot, Jerome; Mornet, Francoise; Le Moine, Olivier; Geairon, Philippe; Guesdon, Stephane. |
| This study aimed to analyse the quality of the sea water flowing into the marine farm of Douhet, a gilthead bream hatchery, from the marsh-seawater reservoir to the entrance of the hatchery. The basin-seawater reservoir is not stratified in the pumping area. As a consequence, the measurements carried out at the surface to the right of the pumping dock give a good evaluation of the quality of the seawater pumped in depth. The high sensitivity of gilthead bream larvae to the water PH during the first two weeks of their larval life, and the values measured in the circuit seem to be an explanatory parameter to the observed mortalities. The water flowing into the hatchery retains, after pre-treatment, a nycthemeral PH variability, with maxima, at the end of the... |
| Tipo: Text |
Palavras-chave: Ammonia nitrogen; PH; Sea bream; Fish hatchery; Reservoir; Water quality; Azote ammoniacal; PH; Daurade royale; Ecloserie; Réserve; Qualité des eaux. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6497.PDF |
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| Rahmani, Alexandra; Mathien, Clémentine; Bidault, Adeline; Le Goïc, Nelly; Paillard, Christine; Pichereau, Vianney. |
| Aims Brown Ring Disease (BRD) is an infection of the Manila clam Ruditapes philippinarum due to the pathogen Vibrio tapetis. During BRD, clams are facing immunodepression and shell biomineralization alteration. In this paper, we studied the role of pH on the growth of the pathogen and formulated hypothesis on the establishment of BRD by V. tapetis. Methods and Results In this study, we monitored the evolution of pH during the growth of V. tapetis in a range of pH and temperatures. We also measured the pH of Manila clam hemolymph and extrapallial fluids during infection by V. tapetis. We highlighted that V. tapetis modulates the external pH during its growth, to a value of 7.70. During the development of BRD, V. tapetis also influences extrapallial fluids... |
| Tipo: Text |
Palavras-chave: BRD; Modulation effect; Neutralizing activity; PH; PH modifications; Ruditapes philippinarum; Vibrio tapetis. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74142/73669.pdf |
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| Lauvset, S. K.; Carter, B. R.; Perez, Ff; Jiang, L-q; Feely, R. A.; Velo, A.; Olsen, A.. |
| Ocean acidification evolves on the background of a natural ocean pH gradient that is the result of the interplay between ocean mixing, biological production and remineralization, calcium carbonate cycling, and temperature and pressure changes across the water column. While previous studies have analyzed these processes and their impacts on ocean carbonate chemistry, none have attempted to quantify their impacts on interior ocean pH globally. Here we evaluate how anthropogenic changes and natural processes collectively act on ocean pH, and how these processes set the vulnerability of regions to future changes in ocean acidification. We use the mapped data product from the Global Ocean Data Analysis Project version 2, a novel method to estimate preformed... |
| Tipo: Text |
Palavras-chave: PH; Remineralization; CaCO3; Anthropogenic; Global ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78793/81066.pdf |
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| Lemonnier, Hugues. |
| En 1996, le vieillissement des fonds de bassins aquacoles de crevettes était présenté comme hypothèse explicative de la dégradation des rendements de production sur certains sites d’élevage. Un travail conséquent avait été réalisé à l’époque dont l'objectif était, à partir d'un inventaire des différents sédiments des fermes aquacoles du Territoire, de mettre en évidence une éventuelle évolution de ce sédiment au fil des cycles d'élevage et son influence sur la productivité. L’objet de ce document est de numériser et de compiler les différentes fiches techniques diffusées à l’époque sous forme papier aux aquaculteurs de la filière crevette de Nouvelle-Calédonie. |
| Tipo: Text |
Palavras-chave: Aquaculture; Litopenaeus stylirostris; Durabilité; Sédiment; Envasement; Matière organique; PH; Déchets. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00656/76762/77918.pdf |
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| Hernandez-ayon, Jose M.; Paulmier, Aurélien; Garcon, Veronique; Sudre, Joel; Montes, Ivonne; Chapa-balcorta, Cecilia; Durante, Giovanni; Dewitte, Boris; Maes, Christophe; Bretagnon, Marine. |
| The oxygen minimum zone (OMZ) of Peru is recognized as a source of CO2 to the atmosphere due to upwelling that brings water with high concentrations of dissolved inorganic carbon (DIC) to the surface. However, the influence of OMZ dynamics on the carbonate system remains poorly understood given a lack of direct observations. This study examines the influence of a coastal Eastern South Pacific OMZ on carbonate system dynamics based on a multidisciplinary cruise that took place in 2014. During the cruise, onboard DIC and pH measurements were used to estimate pCO2 and to calculate the calcium carbonate saturation state (Ω aragonite and calcite). South of Chimbote (9°S), water stratification decreased and both the oxycline and carbocline moved from 150 m depth... |
| Tipo: Text |
Palavras-chave: OMZ; DIC; PH; Omega aragonite; Upwelling Peruvian system. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70004/67919.pdf |
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| Groison, Anne-laure; Suquet, Marc; Cosson, Jacky; Mayer, Ian; Severe, Armelle; Bouquet, Jean-marie; Geffen, Audrey J.; Utne-palm, Anne Christine; Kjesbu, Olav Sigurd. |
| Due to stock declines there is a growing interest in farming of European hake Merluccius merluccius. Thus, knowledge of its sperm biology is of importance not only for purposes of broodstock management, but also for the development of sperm preservation techniques. Hake sperm were collected from mature males caught during the summer-early autumn waters off western Norway and during the winter-early spring in the Bay of Biscay (France). Sperm quality characteristics were assessed after storage at 4 degrees C for 25 +/- 14 h. Average (+/- SD) values for Norwegian and French samples respectively were (i) sperm volume: 3.9 +/- 4.0 and 2.6 +/- 4.0 ml; (ii) spermatozoa concentration: 6.6 +/- 3.2 and 13.9 +/- 5.1 x 10(9) spermatozoa/ml; (iii) spermatocrit: 80.2... |
| Tipo: Text |
Palavras-chave: Cryopreservation; Merluccius merluccius; Osmolality; PH; Sperm motility; Spermatocrit. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11393/8021.pdf |
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| Takahashi, Taro; Sutherland, S. C.; Chipman, D. W.; Goddard, J. G.; Ho, Cheng; Newberger, Timothy; Sweeney, Colm; Munro, D. R.. |
| Climatological mean monthly distributions of pH in the total H+ scale, total CO2 concentration (TCO2), and the degree of CaCO3 saturation for the global surface ocean waters (excluding coastal areas) are calculated using a data set for pCO(2), alkalinity and nutrient concentrations in surface waters (depths <50 m), which is built upon the GLODAP, CARINA and LDEO databases. The mutual consistency among these measured parameters is demonstrated using the inorganic carbon chemistry model with the dissociation constants for carbonic acid by Lueker et al. (2000) and for boric acid by Dickson (1990). Linear potential alkalinity-salinity relationships are established for 24 regions of the global ocean. The mean monthly distributions of pH and carbon chemistry... |
| Tipo: Text |
Palavras-chave: Global ocean; Surface water; PH; Carbonate chemistry; Climatology; Seasonal and decadal change. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40098/38796.pdf |
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| Cochard, Jean-claude. |
| Les crevettes pénéides maintenues captives dans des cages posées sur le fond des bassins d'élevage subissent un stress dû au sédiment qui peut être évalué par la comparaison entre la valeur de la pression osmotique de leur hémolymphe et celle des crevettes libres du même bassin. Les objectifs des travaux réalisés à la station de Saint-Vincent (SASV, Nouvelle Calédonie) étaient de confirmer la variabilité spatiale de l'intensité du stress et de rechercher dans les sédiments un indicateur physique ou chimique corrélé à ce stress. Des lots de 25 à 30 crevettes de 13,2g, pêchées à l'épervier, ont été placés dans des cages de grillage métallique déposées en 12 points du bassin d'élevage. Les cages ont été relevées au bout de 24 heures et la pression osmotique... |
| Tipo: Text |
Palavras-chave: Penaeus stylirostris; Capacité osmorégulatrice; Stress; Sédiment; Aquaculture; Crustacés. crevettes pénéides; PH. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00131/24265/22263.pdf |
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| Lemonnier, Hugues; Bernard, E; Boglio, E; Goarant, Cyrille; Cochard, Jean-claude. |
| Penaeid shrimp reared in earthen ponds are exposed to sediment, which can, in some instances, induce a stress. In seawater, the osmoregulatory capacity (hyporegulation) is a useful tool to compare the physiological condition of shrimp exposed to various stressors. By keeping some shrimp in cages at different locations of a single pond heterogeneous in terms of sediment quality, it was possible, using osmotic pressure (OP), to identify some locations where the stress was maximum and some others where it was minimum. Simultaneously, sediment samples were taken and analysed in order to evaluate some physico-chemical parameters that could be related to the stress observed in the shrimps kept in the cages. This approach allowed to show a significant positive... |
| Tipo: Text |
Palavras-chave: PH; Sediments; Stress; Osmotic pressure; Shrimp physiology. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-1866.pdf |
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| Durand, Patrick. |
| Different parameters have been followed regularly at various times of anchovy (Engraulis encrasicholus ) ripening. Concentration in NaCl and water content as well as values of water activity and pH are constant and remain quite stable during the entire study period. The relatively acid pH value and the quite low measured water activity level created good conditions for preventing microbial putrefaction at room temperature. The free amino acids and non proteinaceous nitrogen increase indicated the modifications occurring in muscular proteins. These changes resulted in an important proteolytic activity modulated by the medium conditions, especially; pH, temperature and ionic strength. The enzymatic activity slowed down regularly with time but was not... |
| Tipo: Text |
Palavras-chave: Enzymatic activity; Nitrogen compounds; PH; Biochemical composition; Cured products. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-1889.pdf |
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| Tuninetti,N.; Blainq,L.; Otero,J.L.. |
| Las contusiones tienen un impacto negativo sobre la calidad de la carne y son una fuente importante de información sobre el bienestar animal. Las contusiones reflejan fallas en las prácticas de manejo, diseño incorrecto de las instalaciones o falta de formación del personal. La carne de pH elevado es el resultado de una depleción del glucógeno antes de la matanza y la consecuente inhabilidad para acumular ácido láctico. Esta carne tiene apariencia seca, firme y oscura (DFD= dark, firm, dry), es menos tierna, tiene defectos de palatabilidad, es poco apreciada por el consumidor y facilita el desarrollo de microorganismos. Se estudió la presencia de contusiones en las canales bovinas y los aspectos relacionados con alteraciones en la calidad de la carne, como... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Contusiones; PH; Canales; Bovinos; PH; Carcass; Bovine. |
| Ano: 2017 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1668-34982017000100004 |
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| Landeiro,Victor L; Pepinelli,Mateus; Hamada,Neusa. |
| Taxonomically, blackflies (Simuliidae) are among the best-known aquatic insects in Brazil. However, information on their distribution is lacking for many regions. We sampled simuliids in 50 streams in the Chapada Diamantina region, State of Bahia, located in three distinct geographical areas, 20 at Lençóis, 18 at Mucugê, and 12 at Rio de Contas. We analyzed simuliid species richness and distribution in the Chapada Diamantina area as a whole, as well as in each of the three distinct geographical areas. We collected 20 species, three of which were not yet described and two were described after our sampling. The three areas are distinct in relation to environmental variables, mainly owing to differences in altitude and water pH. Four species were restricted... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neotropical stream; Brazilian savanna; Altitude; PH. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2009000300006 |
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| Martínez-Cárdenas,Leonardo; Frías-Quintana,Carlos A.; Álvarez-González,Carlos A.; Jiménez-Martínez,Luis D.; Martínez-García,Rafael; Hernández-Almeida,Oscar U.; Bello-Pineda,Javier; Arellano-Méndez,Leonardo U.; Ponce-Palafox,Jesús T.. |
| ABSTRACT Short-tailed pipe fish (Microphis brachyurus) is a freshwater organism with high economic potential for the aquarium hobby, so it is necessary to implement methods to promote its culture through studies of digestive physiology. General activities of acid and alkaline proteases were evaluated, as well as the effect of pH, temperature and inhibitors. The optimal pH of stomach proteases was 2, while the optimal pH of intestinal proteases was 10. Optimal temperature for the acidic proteases was 35 ºC, while for alkaline proteases it was 45 ºC. Thermal stability showed high resistance at 35 ºC for both acid and alkaline proteases (above 100% residual activity). Acid proteases are resistant at pH 2 (50% of residual activity), meanwhile alkaline... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzyme activity; Sygnathidae; PH; Protease inhibitors; Temperature. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000200212 |
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| Souza,Carine de F.; Pereira Junior,Waterloo; Garcia,Luciano de O.; Santos,Felipe C. dos; Baldisserotto,Bernardo. |
| ABSTRACT This study analyzed the relationship between several water quality parameters (pH, hardness, alkalinity, turbidity, iron and manganese) levels measured over a 16 year period with fish distribution and aquaculture in the state of Rio Grande do Sul, Southern Brazil. The mean pH values were within a neutral range (6.5-7.5), but the maximum and minimum values reached inappropriate levels for fish farming in some cities. Alkalinity levels were very low (except in the southwest region of the state), which may have contributed to pH variation. Hardness, turbidity, iron (except the region near Caçapava do Sul City) and manganese were within safe ranges for fish farming; however, turbidity levels occasionally increased to levels outside the safe range. In... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alkalinity; Hardness; Iron; PH; Turbidity. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000300205 |
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| Registros recuperados: 309 | |
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