76
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Ji C, Legrand J, Chen Z, Zhang W. Nitrogen limitation on growth, starch accumulation and hydrogen metabolism of marine green alga Platymonas subcordiformis. J Biotechnol 2008. [DOI: 10.1016/j.jbiotec.2008.07.1358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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77
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Blel W, Legentilhomme P, Legrand J, Bénézech T, Gentil-Lelièvre CL. Hygienic design: Effect of hydrodynamics on the cleanability of a food processing line. AIChE J 2008. [DOI: 10.1002/aic.11559] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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78
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Degrenne B, Cogne G, Pruvost J, Legrand J. Role of acetate and light attenuation in hydrogen production by chlamydomonas reinhardii. J Biotechnol 2008. [DOI: 10.1016/j.jbiotec.2008.07.1315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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79
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Ruffino L, Bourgeois K, Vidal E, Icard J, Torre F, Legrand J. Introduced predators and cavity-nesting seabirds: unexpected low level of interaction at breeding sites. CAN J ZOOL 2008. [DOI: 10.1139/z08-070] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mechanisms by which introduced predators and long-lived seabirds interact and even coexist are still poorly known. Here, the interactions between the widely introduced black rat ( Rattus rattus (L., 1758)) and an endemic Mediterranean cavity-nesting seabird, the yelkouan shearwater ( Puffinus yelkouan (Acerbi, 1827)), were for the first time investigated for a set of 60 suitable breeding cavities throughout the entire breeding cycle of this seabird. Our results pointed out that rat visits to cavities were significantly higher when shearwaters had left the colony for their interbreeding exodus. Among the set of suitable breeding cavities, yelkouan shearwaters preferentially selected the deepest and the most winding cavities for breeding. Very few rat visits were recorded at the shearwater-occupied cavities and no predation event was recorded. These intriguing results reveal a low level of interaction between introduced black rats and yelkouan shearwaters, which may have facilitated their long-term coexistence for thousands of years on some Mediterranean islands.
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80
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Nicorescu I, Loisel C, Vial C, Riaublanc A, Djelveh G, Cuvelier G, Legrand J. Combined effect of dynamic heat treatment and ionic strength on denaturation and aggregation of whey proteins – Part I. Food Res Int 2008. [DOI: 10.1016/j.foodres.2008.05.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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81
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Rehimi F, Legrand J, Aloui F. Electrochemical method for precise determination of wall shear rate. RUSS J ELECTROCHEM+ 2008. [DOI: 10.1134/s1023193508040095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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82
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Pruvost J, Legrand J, Legentilhomme P, Muller-Feuga A. Effect of Inlet Type on Shear Stress and Mixing in an Annular Photobioreactor Involving a Swirling Decaying Flow. CAN J CHEM ENG 2008. [DOI: 10.1002/cjce.5450820310] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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83
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Vauchel P, Kaas R, Arhaliass A, Baron R, Legrand J. A New Process for Extracting Alginates from Laminaria digitata: Reactive Extrusion. FOOD BIOPROCESS TECH 2008. [DOI: 10.1007/s11947-008-0082-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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84
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Mojaat M, Pruvost J, Foucault A, Legrand J. Effect of organic carbon sources and Fe2+ ions on growth and β-carotene accumulation by Dunaliella salina. Biochem Eng J 2008. [DOI: 10.1016/j.bej.2007.09.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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85
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Vauchel P, Arhaliass A, Legrand J, Kaas R, Baron R. DECREASE IN DYNAMIC VISCOSITY AND AVERAGE MOLECULAR WEIGHT OF ALGINATE FROM LAMINARIA DIGITATA DURING ALKALINE EXTRACTION(1). JOURNAL OF PHYCOLOGY 2008; 44:515-517. [PMID: 27041205 DOI: 10.1111/j.1529-8817.2008.00482.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1-4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted alginates.
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86
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Arhaliass A, Legrand J, Vauchel P, Fodil-Pacha F, Lamer T, Bouvier JM. The Effect of Wheat and Maize Flours Properties on the Expansion Mechanism During Extrusion Cooking. FOOD BIOPROCESS TECH 2007. [DOI: 10.1007/s11947-007-0038-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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87
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Mojaat M, Foucault A, Pruvost J, Legrand J. Optimal selection of organic solvents for biocompatible extraction of beta-carotene from Dunaliella salina. J Biotechnol 2007; 133:433-41. [PMID: 18155312 DOI: 10.1016/j.jbiotec.2007.11.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/20/2007] [Accepted: 11/12/2007] [Indexed: 12/18/2022]
Abstract
In the aim of beta-carotene biocompatible extraction, toxicity of various pure solvents belonging to different homologous series has been investigated for Dunaliella salina. The results showed that solvents having logP(oct) > 5 or having a molecular weight over 150 g/mol can be considered biocompatible for this microalga. The membrane critical solvent concentration for each series of solvents has been calculated applying Osborne's model, showing that the aliphatic chlorinated hydrocarbon is the most toxic family studied. Mixtures of a biocompatible solvent (decane) with a toxic solvent (CH(2)Cl(2), MEK, MTBE) have been studied. The beta-carotene extraction ability of CH(2)Cl(2)-decane mixture was found six times more efficient than with pure decane. It has been demonstrated that the extraction ability of solvent depends on its affinity with the product extracted and on its concentration incorporated in the cellular membrane.
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88
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Altamimi Z, Collilieux X, Legrand J, Garayt B, Boucher C. ITRF2005: A new release of the International Terrestrial Reference Frame based on time series of station positions and Earth Orientation Parameters. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jb004949] [Citation(s) in RCA: 644] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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89
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Bonnaud E, Bourgeois K, Vidal E, Kayser Y, Tranchant Y, Legrand J. Feeding Ecology of a Feral Cat Population on a Small Mediterranean Island. J Mammal 2007. [DOI: 10.1644/06-mamm-a-031r2.1] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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90
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Legrand J, Grais RF, Boelle PY, Valleron AJ, Flahault A. Understanding the dynamics of Ebola epidemics. Epidemiol Infect 2006; 135:610-21. [PMID: 16999875 PMCID: PMC2870608 DOI: 10.1017/s0950268806007217] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ebola is a highly lethal virus, which has caused at least 14 confirmed outbreaks in Africa between 1976 and 2006. Using data from two epidemics [in Democratic Republic of Congo (DRC) in 1995 and in Uganda in 2000], we built a mathematical model for the spread of Ebola haemorrhagic fever epidemics taking into account transmission in different epidemiological settings. We estimated the basic reproduction number (R0) to be 2.7 (95% CI 1.9-2.8) for the 1995 epidemic in DRC, and 2.7 (95% CI 2.5-4.1) for the 2000 epidemic in Uganda. For each epidemic, we quantified transmission in different settings (illness in the community, hospitalization, and traditional burial) and simulated various epidemic scenarios to explore the impact of control interventions on a potential epidemic. A key parameter was the rapid institution of control measures. For both epidemic profiles identified, increasing hospitalization rate reduced the predicted epidemic size.
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91
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Bouaouina H, Desrumaux A, Loisel C, Legrand J. Functional properties of whey proteins as affected by dynamic high-pressure treatment. Int Dairy J 2006. [DOI: 10.1016/j.idairyj.2005.05.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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92
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Haydont V, Gilliot O, Bourgier C, Legrand J, Frangois A, Frascogna V, Bourhis J, Vozenin-Brotons M. 136 Simultaneous normal tissue protection and increased tumor radiosensitivity : A new goal for pravastatin? Radiother Oncol 2006. [DOI: 10.1016/s0167-8140(06)80615-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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93
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Pruvost J, Legrand J, Legentilhomme P, Muller-Feuga A. Simulation of microalgae growth in limiting light conditions: Flow effect. AIChE J 2006. [DOI: 10.1002/aic.690480520] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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94
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Marchal L, Legrand J, Foucault A. Mass transport and flow regimes in centrifugal partition chromatography. AIChE J 2006. [DOI: 10.1002/aic.690480811] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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95
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Raillard C, Héquet V, Le Cloirec P, Legrand J. Photocatalytic oxidation of methyl ethyl ketone over sol-gel and commercial TiO2 for the improvement of indoor air. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 53:107-15. [PMID: 16862780 DOI: 10.2166/wst.2006.343] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This work focuses on the photocatalytic oxidation of gaseous methyl ethyl ketone chosen as a typical indoor air pollutant. Two types of TiO coatings were prepared and deposited on glass plates: one using the commercial Degussa P25 TiO2 and the other one by sol-gel method. The first objective of this study was to compare different ways of preparing thin films of sol-gel TiO2 coated on glass plates, taking into account their general aspect and their photocatalytic efficiency. Several parameters were tested, such as the stabilising agent, the glass type of the support, the number of coatings and the calcination temperature. One of the synthesised materials was then kept to carry out the following study. The study aimed to assess the influence of TiO2 coating types on the effect of water vapour. This was achieved by performing MEK photocatalytic degradation kinetics under two levels of humidity at a fixed temperature. Experimental results were then modelled by the Langmuir-Hinshelwood equation. The obtained parameters gave specific trends in function of the considered catalyst. The second part of this work was to identify MEK degradation byproducts during its photocatalytic oxidation. The main detected intermediate was acetaldehyde, followed by methyl formate. A MEK degradation pathway was then proposed.
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96
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Mathieu F, Ugazio S, Carnelle G, Duciní Y, Legrand J. Complex coacervation of the gelatin–poly(acrylic acid) system. J Appl Polym Sci 2006. [DOI: 10.1002/app.23899] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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97
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Dumont E, Fayolle F, Legrand J. Electrodiffusional wall shear rate analysis in scraped surface heat exchanger. AIChE J 2006. [DOI: 10.1002/aic.690460606] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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98
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Fouchard S, Hemschemeier A, Caruana A, Pruvost J, Legrand J, Happe T, Peltier G, Cournac L. Autotrophic and mixotrophic hydrogen photoproduction in sulfur-deprived chlamydomonas cells. Appl Environ Microbiol 2005; 71:6199-205. [PMID: 16204539 PMCID: PMC1265920 DOI: 10.1128/aem.71.10.6199-6205.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Chlamydomonas reinhardtii cells, H2 photoproduction can be induced in conditions of sulfur deprivation in the presence of acetate. The decrease in photosystem II (PSII) activity induced by sulfur deprivation leads to anoxia, respiration becoming higher than photosynthesis, thereby allowing H2 production. Two different electron transfer pathways, one PSII dependent and the other PSII independent, have been proposed to account for H2 photoproduction. In this study, we investigated the contribution of both pathways as well as the acetate requirement for H2 production in conditions of sulfur deficiency. By using 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), a PSII inhibitor, which was added at different times after the beginning of sulfur deprivation, we show that PSII-independent H2 photoproduction depends on previously accumulated starch resulting from previous photosynthetic activity. Starch accumulation was observed in response to sulfur deprivation in mixotrophic conditions (presence of acetate) but also in photoautotrophic conditions. However, no H2 production was measured in photoautotrophy if PSII was not inhibited by DCMU, due to the fact that anoxia was not reached. When DCMU was added at optimal starch accumulation, significant H2 production was measured. H2 production was enhanced in autotrophic conditions by removing O2 using N2 bubbling, thereby showing that substantial H2 production can be achieved in the absence of acetate by using the PSII-independent pathway. Based on these data, we discuss the possibilities of designing autotrophic protocols for algal H2 photoproduction.
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99
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Fouchard S, Hemschemeier A, Caruana A, Pruvost J, Legrand J, Happe T, Peltier G, Cournac L. Autotrophic and mixotrophic hydrogen photoproduction in sulfur-deprived chlamydomonas cells. Appl Environ Microbiol 2005. [PMID: 16204539 DOI: 10.1128/aem.71.10.6199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
In Chlamydomonas reinhardtii cells, H2 photoproduction can be induced in conditions of sulfur deprivation in the presence of acetate. The decrease in photosystem II (PSII) activity induced by sulfur deprivation leads to anoxia, respiration becoming higher than photosynthesis, thereby allowing H2 production. Two different electron transfer pathways, one PSII dependent and the other PSII independent, have been proposed to account for H2 photoproduction. In this study, we investigated the contribution of both pathways as well as the acetate requirement for H2 production in conditions of sulfur deficiency. By using 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), a PSII inhibitor, which was added at different times after the beginning of sulfur deprivation, we show that PSII-independent H2 photoproduction depends on previously accumulated starch resulting from previous photosynthetic activity. Starch accumulation was observed in response to sulfur deprivation in mixotrophic conditions (presence of acetate) but also in photoautotrophic conditions. However, no H2 production was measured in photoautotrophy if PSII was not inhibited by DCMU, due to the fact that anoxia was not reached. When DCMU was added at optimal starch accumulation, significant H2 production was measured. H2 production was enhanced in autotrophic conditions by removing O2 using N2 bubbling, thereby showing that substantial H2 production can be achieved in the absence of acetate by using the PSII-independent pathway. Based on these data, we discuss the possibilities of designing autotrophic protocols for algal H2 photoproduction.
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100
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De Pilli T, Severini C, Baiano A, Derossi A, Arhaliass A, Legrand J. Effects of operating conditions on oil loss and properties of products obtained by co-rotating twin-screw extrusion of fatty meal: preliminary study. J FOOD ENG 2005. [DOI: 10.1016/j.jfoodeng.2004.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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