Shahzad T.,French National Institute for Agricultural Research |
Chenu C.,Agro Paris Technology |
Repincay C.,French National Institute for Agricultural Research |
Mougin C.,French National Institute for Agricultural Research |
And 2 more authors.
Soil Biology and Biochemistry | Year: 2012
Grazing or mowing is central to the management of grasslands and may alter mineralization of soil organic matter (SOM) and soil carbon (C) stocks. Some studies have shown grazing-induced reductions in total soil respiration suggesting decreases in SOM mineralization. However, it has also been suggested that grazing may increase SOM mineralization, based on observations of increased soluble C, microbial biomass and mineral nitrogen (N) in soil after clipping. No studies to date have directly measured SOM mineralization to determine the effects of grazing on SOM mineralization and the underlying mechanisms. We examined the effect of clipping on soil-derived CO 2 efflux (Rs) for six gramineae and one leguminous species typical of temperate grasslands. Continuous 13C labeling of monocultures coupled with a new method of directly measuring Rs and the rhizosphere priming effect (RPE i.e. Rs from planted soils minus respiration from bare soils) in perennial herbaceous plants was used. For a model species, Lolium perenne, the clipping effects on aboveground biomass production, mineral N and soluble C in soil, microbial biomass and microbial community composition were also quantified. We found that clipping decreased the RPE and Rs (SOM mineralization) within 48 hours for all the studied species. For Lolium perenne, this reduced SOM mineralization persisted for one month after clipping. Moreover, clipping reduced the production of aboveground biomass and the total N assimilated by the plants. These changes increased N availability in soil and induced shifts in the soil microbial community structure favoring gram positive bacteria (i16:0) over saprophytic fungi (18:2ω6). The strong correlation of fungi (18:2ω6) with Rs across treatments suggests that saprophytic fungi play a key role in SOM mineralization. In conclusion, our study shows that plant clipping decelerates SOM mineralization and induces shifts in microbial community structure, most likely as an indirect effect of clipping on plant N uptake. © 2012 Elsevier Ltd.
Rasoamanana R.,Agro Paris Technology |
Rasoamanana R.,French National Institute for Agricultural Research |
Chaumontet C.,Agro Paris Technology |
Chaumontet C.,French National Institute for Agricultural Research |
And 8 more authors.
Journal of Nutrition | Year: 2012
This study focused on the fate of the satiating potency of dietary fibers when solubilized in a fat- containing medium. Fourteen percent of either guar gum (GG) or fructo-oligosaccharide (FOS) or a mixture of the 2 (GG-FOS, 5% GG and 9% FOS) were solubilized in water or an oil emulsion (18-21% rapeseed oil in water, v:v) and administered by gavage to mice before their food intake was monitored. When compared with water (control), only GG-FOS solubilized in water or in the oil emulsion reduced daily energy intake by 21.1 and 14.1%, respectively. To further describe this effect, the meal pattern was characterized and showed that GG-FOS increased satiation without affecting satiety by diminishing the size and duration of meals for up to 9 h after administration independently of the solubilization medium. The peripheral blockade of gut peptide receptors showed that these effects were dependent on the peripheral signaling of cholecystokinin but not of glucagon-like peptide 1, suggesting that anorectic signals emerge from the upper intestine rather than from distal segments. Measurements of neuronal activation in the nucleus of solitary tract supported the hypothesis of vagal satiation signaling because a 3-fold increase in c-Fos protein expression was observed in that nucleus after the administration of GG-FOS, independently of the solubilization medium. Taken together, these data suggest that a mixture of GG and FOS can maintain its appetite suppressant effect in fatty media. Adding these dietary fibers to fat-containing foods might therefore be useful in managing food intake. © 2012 American Society for Nutrition.
Alletto L.,Purpan Engineering School |
Coquet Y.,Agro Paris Technology |
Bergheaud V.,French National Institute for Agricultural Research |
Benoit P.,French National Institute for Agricultural Research
Chemosphere | Year: 2012
Laboratory incubations were performed in order to evaluate the dissipation of the proherbicide isoxaflutole in seedbed layer soil samples from conventional and conservation tillage systems and in maize and oat residues left at the soil surface under conservation tillage. The effects of temperature and water pressure head on radiolabelled isoxaflutole degradation were studied for each sample for 21d. Mineralisation of isoxaflutole was low for all samples and ranged from 0.0% to 0.9% of applied 14C in soil samples and from 0.0% to 2.4% of applied 14C in residue samples. In soil samples, degradation half-life of isoxaflutole ranged from 9 to 26h, with significantly higher values under conservation tillage. In residue samples, degradation half-life ranged from 3 to 31h, with significantly higher values in maize residues, despite a higher mineralisation and bound residue formation than in oat residues. Whatever the sample, most of the applied 14C remained extractable during the experiment and, after 21d, less than 15% of applied 14C were unextractable. This extractable fraction was composed of diketonitrile, benzoic acid derivative and several unidentified metabolites, with one of them accounting for more than 17% of applied 14C. This study showed that tillage system design, including crop residues management, could help reducing the environmental impacts of isoxaflutole. © 2012 Elsevier Ltd.
Mesurolle J.,French National Institute for Agricultural Research |
Saint-Eve A.,Agro Paris Technology |
Deleris I.,French National Institute for Agricultural Research |
Souchon I.,French National Institute for Agricultural Research
Molecules | Year: 2013
The aim of this work was to gain insight into the effect of food formulation on aroma release and perception, both of which playing an important role in food appreciation. The quality and quantity of retronasal aroma released during food consumption affect the exposure time of olfactory receptors to aroma stimuli, which can influence nutritional and hedonic characteristics, as well as consumption behaviors. In yogurts, fruit preparation formulation can be a key factor to modulate aroma stimulation. In this context, the impact of size and hardness of fruit pieces in fat-free pear yogurts was studied. Proton Transfer Reaction-Mass Spectrometry (PTR-MS) was used to allow sensitive and on-line monitoring of volatile odorous compound release in the breath during consumption. In parallel, a trained panel used sensory profile and Temporal Dominance of Sensations (TDS) methods to characterize yogurt sensory properties and their dynamic changes during consumption. Results showed that the size of pear pieces had few effects on aroma release and perception of yogurts, whereas fruit hardness significantly influenced them. Despite the fact that yogurts presented short and similar residence times in the mouth, this study showed that fruit preparation could be an interesting formulation factor to enhance exposure time to stimuli and thus modify food consumption behaviors. These results could be taken into account to formulate new products that integrate both nutritional and sensory criteria. © 1996-2013 MDPI AG (Basel, Switzerland).
Dennehy C.,National University of Ireland |
Lawlor P.G.,Teagasc |
Croize T.,Agro Paris Technology |
Jiang Y.,National University of Ireland |
And 3 more authors.
Waste Management | Year: 2016
Anaerobic co-digestion of food waste (FW) and pig manure (PM) was undertaken in batch mode at 37°C in order to identify and quantify the synergistic effects of co-digestion on the specific methane yield (SMY) and reaction kinetics. The effects of the high initial volatile fatty acid (VFA) concentrations in PM on synergy observed during co-digestion, and on kinetic modelling were investigated. PM to FW mixing ratios of 1/0, 4/1, 3/2, 2/3, 1/4 and 0/1 (VS basis) were examined. No VFA or ammonia inhibition was observed. The highest SMY of 521±29ml CH4/gVS was achieved at a PM/FW mixing ratio of 1/4. Synergy in terms of both reaction kinetics and SMY occurred at PM/FW mixing ratios of 3/2, 2/3 and 1/4. Initial VFA concentrations did not explain the synergy observed. Throughout the study the conversion of butyric acid was inhibited. Due to the high initial VFA content of PM, conventional first order and Gompertz models were inappropriate for determining reaction kinetics. A dual pooled first order model was found to provide the best fit for the data generated in this study. The optimal mixing ratio in terms of both reaction kinetics and SMY was found at a PM/FW mixing ratio of 1/4. © 2016 Elsevier Ltd.
Guimberteau M.,French National Center for Scientific Research |
Perrier A.,Agro Paris Technology |
Laval K.,French National Center for Scientific Research |
Polcher J.,French National Center for Scientific Research
Hydrology and Earth System Sciences | Year: 2012
The purpose of this study is to test the ability of the Land Surface Model SECHIBA to simulate water budget and particularly soil moisture at two different scales: regional and local. The model is forced by NLDAS data set at 1/8th degree resolution over the 1997-1999 period. SECHIBA gives satisfying results in terms of evapotranspiration and runoff over the US compared with four other land surface models, all forced by NLDAS data set for a common time period. The simulated soil moisture is compared to in-situ data from the Global Soil Moisture Database across Illinois by computing a soil wetness index. A comprehensive approach is performed to test the ability of SECHIBA to simulate soil moisture with a gradual change of the vegetation parameters closely related to the experimental conditions. With default values of vegetation parameters, the model overestimates soil moisture, particularly during summer. Sensitivity tests of the model to the change of vegetation parameters show that the roots extraction parameter has the largest impact on soil moisture, other parameters such as LAI, height or soil resistance having a minor impact. Moreover, a new evapotranspiration computation including bare soil evaporation under vegetation has been introduced into the model. The results point out an improvement of the soil moisture simulation when this effect is taken into account. Finally, soil moisture sensitivity to precipitation variation is addressed and it is shown that soil moisture observations can be rather different, depending on the method of measuring field capacity. When the observed field capacity is deducted from the observed volumetric water profiles, simulated soil wetness index is closer to the observations. © 2012 Author(s).
Lemaire V.,Orange Group |
Ismaili O.A.,Orange Group |
Cornuejols A.,Agro Paris Technology
Proceedings of the International Joint Conference on Neural Networks | Year: 2015
Over the last years, researchers have focused their attention on a new approach, supervised clustering, that combines the main characteristics of both traditional clustering and supervised classification tasks. Motivated by the importance of the initialization in the traditional clustering context, this paper explores to what extent supervised initialization step could help traditional clustering to obtain better performances on supervised clustering tasks. This paper reports experiments which show that the simple proposed approach yields a good solution together with significant reduction of the computational cost. © 2015 IEEE.
Hebel P.,INA PG Agro Paris Technology CREDOC |
Pilorin T.,Agro Paris Technology
Cahiers de Nutrition et de Dietetique | Year: 2012
The speech marked the food more and more a fundamental divide. First, a functional vision restricted feeding health. Power is medicalized and becomes a personal matter, probably under the influence of Anglo-Saxon and Protestant, which allows the individual some freedom from his choices. Maintenance decisions tend to focus not on gastronomic or symbolic reasons, but on medical grounds. A phenomenon of individualization is at work in the food. Between 1988 and 2007, changes in mental representations of eating well and has greatly progressed from a diet-friendly food to health. The question that remains unanswered is that of behavioral changes related to the reduction of cultural transmission consecutive changes representations?. © 2012 Société française de nutrition. Published by Elsevier Masson SAS. All rights reserved.
Canneva G.,Agro Paris Technology |
Water Science and Technology: Water Supply | Year: 2011
Performance assessment has recently been applied to water utilities in France. Performance indicators (PIs) were initially developed as an aid to the control of public service delegation by local authorities. After a long process, a group of PIs was integrated into mandatory annual reports on service quality and price, in order to better inform utility users and reinforce the regulation of the sector by local public authorities. As water utilities in France are highly fragmented, this development in isolation may have only limited effects. The additional comparison of performance is likely to improve service quality and efficiency and keep prices affordable. The French national agency for water (ONEMA) - created in 2006 - is in charge of building the monitoring system of water utility performance. This paper presents the objectives of this monitoring system, the methodology used to create it and its shortcomings. Due to the large number of utilities, the data collection process faces difficulties. Some conclusions are drawn on how to obtain stronger involvement of local authorities. © IWA Publishing 2011.
Berne A.,AGRO PARIS Technology
Water Practice and Technology | Year: 2013
Preserving the quality of raw water for drinking likely to be affected by diffuse pollution in water supply ponds (WSPs) is a major public health issue. We must therefore implement efficient and sustainable technical measures that guarantee the long-term protection of this resource. Such measures can prove to be a considerable constraint for farm managers and farm owners. It is consequently absolutely necessary that the compensation provided for is in line with these constraints. High stakes and high constraints must result in high compensation. The catchment protection perimeter tool, reviewed and enlarged to encompass up to 100% of the WSP, renewed and in-depth dialogue based on solid technical and economic studies and a new compensation method established from the principle of discounted loss capitalisation over a duration equal to the lease, are all new and promising tools to solve this essential problem for sustainable development throughout the territory and to preserve the health of its population. © IWA Publishing 2013.