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Registros recuperados: 38 | |
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Loizeau, Veronique; Menesguen, Alain. |
A five-compartment steady-state food web model is proposed for the benthic food web leading to the dab. Three exposure pathways are considered in the description of accumulation by benthic animals: ingestion of particulate contaminants associated with either sediment or phytoplankton, and respiratory uptake of free dissolved contaminant in overlaying water. Application of the model to a simple food web in the Bay of Seine (Eastern Channel) indicates that : a) feeding is the principal route of contamination, especially for PCB which have more than four chlorine atoms in the molecule ; b) excretion and growth rates, phytoplankton lipid fraction and organic carbon content of sediment are the parameters which mostly determine the chemical bioaccumulation in... |
Tipo: Text |
Palavras-chave: MODEL; PCB; FOOD WEB; BENTHIC INVERTEBRATES; DAB. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21127/18747.pdf |
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Prudent, M.; Lecomte, A.; Bouchet, J.P.; Bertin, N.; Causse, M.; Génard, M.. |
A mechanistic model predicting the accumulation of tomato fruit sugars was developed in order (i) to dissect the relative influence of three underlying processes: assimilate supply (S), metabolic transformation of sugars into other compounds (M), and dilution by water uptake (D); and (ii) to estimate the genetic variability of S, M, and D. The latter was estimated in a population of 20 introgression lines derived from the introgression of a wild tomato species (Solanum chmielewskii) into S. lycopersicum, grown under two contrasted fruit load conditions. Low load systematically decreased D in the whole population, while S and M were targets of genotype×fruit load interactions. The sugar concentration positively correlated to S and D when the variation was... |
Tipo: Journal Article |
Palavras-chave: CHARGE EN FRUITS; SUGAR ACCUMULATION; INTROGRESSION LINES; ASSIMILATE SUPPLY; DILUTION; FRUIT LOAD; FRUIT QUALITY; GENETIC VARIATION; METABOLISM; MODEL; STARCH ACCUMULATION SOLANUM CHMIELEWSKII. |
Ano: 2011 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2011f98e9db2&uri=/notices/prodinra1/2011/05/ |
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Lombaert, E.; Boll, R.; Lapchin, L.. |
Background: The spread of agriculture greatly modified the selective pressures exerted by plants on phytophagous insects, by providing these insects with a high-level resource, structured in time and space. The life history, behavioural and physiological traits of some insect species may have evolved in response to these changes, allowing them to crowd on crops and to become agricultural pests. Dispersal, which is one of these traits, is a key concept in evolutionary biology but has been over-simplified in most theoretical studies. We evaluated the impact of the local-scale dispersal strategy of phytophagous insects on their fitness, using an individual-based model to simulate population dynamics and dispersal between leaves and plants, by walking and... |
Tipo: Journal Article |
Palavras-chave: APHIDS; PHYTOPHAGOUS; POPULATION DYNAMICS; DISPERSAL STRATEGY; MODEL; PLANT CHARACTERISTICS; EVOLUTION. |
Ano: 2006 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2007b56bf41e&uri=/notices/prodinra1/2009/10/ |
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Roques, L.; Chekroun, M.D.. |
There is a gap between single-species model predictions, and empirical studies, regarding the effect of habitat fragmentation per se, i.e., a process involving the breaking apart of habitat without loss of habitat. Empirical works indicate that fragmentation can have positive as well as negative effects, whereas, traditionally, single-species models predict a negative effect of fragmentation. Within the class of reaction-diffusion models, studies almost unanimously predict such a detrimental effect. In this paper, considering a single-species reaction-diffusion model with a removal -- or similarly harvesting -- term, in two dimensions, we find both positive and negative effects of fragmentation of the reserves, i.e. the protected regions where no removal... |
Tipo: Journal Article |
Palavras-chave: MODELISATION; MODELE MATHEMATIQUE; HABITAT; RECOLTE; MODELE SPATIAL; REACTION-DIFFUSION; BIOLOGIE DE LA CONSERVATION; DENSITE DE POPULATION FRAGMENTATION; SINGLE-SPECIES MODEL; HARVESTING; SPATIAL PATTERNS; CONSERVATION BIOLOGY; MODEL. |
Ano: 2009 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20096947ae43&uri=/notices/prodinra1/2010/02/ |
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Delmotte, S.; Lopez Ridaura, S.; Barbier, J.M.; Wery, J.. |
The development of organic farming is nowadays seen as a possible solution to meet the different objectives of sustainable development. In the Camargue, South of France, environmental issues are strongly linked with agriculture, and stakeholders are in need of integrated approaches to analyse the plausible impacts of alternative farming systems at multiple scales, particularly at regional scale. Evaluating alternative farming systems at multiple scales requires the quantification of different indicators meaningful for different actors in support of the negotiation and decision making process. With this challenge in mind, we developed a framework for Prospective, Integrated, Multiscale and Participative Assessment of Agricultural Systems (PIMPAAS),... |
Tipo: Conference Paper |
Palavras-chave: ANALYSE PROSPECTIVE; EVALUATION PARTICIPATIVE; EVALUATION MULTIECHELLE; EVALUATION INTEGREE PROSPECTIVE EVALUATION; INTEGRATED EVALUATION; MULTISCALE EVALUATION; PARTICPATORY EVALUATION; SCENARIO EVALUATION; AGRO-ECOSYSTEM EVALUATION; MODEL. |
Ano: 2010 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20101d3faca8&uri=/notices/prodinra1/2011/02/ |
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Registros recuperados: 38 | |
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