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Meta-analysis of individual and combined effects of mycotoxins on growing pigs Scientia Agricola
Andretta,Ines; Kipper,Marcos; Hauschild,Luciano; Lehnen,Cheila Roberta; Remus,Aline; Melchior,Raquel.
ABSTRACT Little is known about the toxicity of concomitantly occurring mycotoxins in pig diets. This study was conducted to evaluate, through meta-analysis, the individual and the combined effects of mycotoxins on pig performance. The meta-analysis followed three sequential analyses (graphical, correlation, and variance-covariance) based on a database composed of 85 published papers, 1,012 treatments and 13,196 animals. Contamination of diets with individual mycotoxins reduced (p < 0.05) feed intake by 14 % and weight gain by 17 %, while combined mycotoxins reduced the same responses by 42 % and 45 %, respectively, in comparison with the non-challenged group. The correlation (p < 0.05) between reduction in weight gain (ΔG) and reduction in feed...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Modelling; Sanitary challenge; Swine; Toxicology.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000400328
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Methodological and empirical progress and challenges in integrated assessment of agricultural systems and policies AgEcon
van Ittersum, Martin K.; Heckelei, Thomas; Oude Lansink, Alfons G.J.M.; Wolf, Joost; Kanellopoulos, Argyris; Britz, Wolfgang.
In this contribution we first present a methodology for integrated assessment of agricultural systems (SEAMLESS Integrated Framework), illustrate its application in an integrated assessment of high commodity prices and then discuss its flexibility and limitations. From there we take a broader view and reflect on key scientific and empirical questions with respect to the development of research tools for the integrated assessment of agricultural systems.
Tipo: Presentation Palavras-chave: Agricultural systems; Integrated assessment; Modelling; Agricultural and Food Policy; Farm Management.
Ano: 2011 URL: http://purl.umn.edu/119329
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Méthodologie pour une simulation des transformations granulométriques de sables de la zone d'avant-côte ArchiMer
Barusseau, Jp; Diouf, Mb; De La Bardonnie, M; El Ghandour, N.
The grain-size of mature coastal sands changes rapidly in response to the variation of the energy regime which provokes either erosion or deposition of fractions of the textural assemblage. Whatever the dynamic conditions, questions of paramount importance such as the size of grain populations transported simultaneously, the most common size of the grains in movement and the grain-size range of the sediment fraction involved ape still poorly understood. The present paper deals with an attempt to describe this fraction without any consideration of the processes responsible for the observed changes. A major problem results from the fact that the distribution of the mobilized fraction cannot be known and described by direct comparison between the initial and...
Tipo: Text Palavras-chave: Granulométrie; Fraction mobile; Modélisation; Simulation; Grain-size; Mobile fraction; Modelling; Simulation.
Ano: 1999 URL: http://archimer.ifremer.fr/doc/00325/43619/43919.pdf
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Methods for the Assessment of Livestock Development Interventions in Smallholder Livestock Systems AgEcon
Rushton, Jonathan.
This Working Paper presents a framework for assessing the impact of livestock diseases on the household economy and at local level. The framework is designed to help decision and policy makers in their selection of pro-poor livestock interventions. It should also help to protect them from making decisions under unwanted pressure from strong, non-objective political voices. The immediate users of the assessment methods presented in the Working Paper are expected to be consultants who have to evaluate interventions on behalf of their clients. These clients may be multi and bi lateral donors and, possibly, NGOs. Other users of the output could be governments receiving aid and communities receiving support. The author has drawn upon past experience to...
Tipo: Working or Discussion Paper Palavras-chave: Livestock; Animal; Production; Health; Interventions; Prioritisation; Modelling; Households; Bolivia; Kenya; India; Livestock Production/Industries.
Ano: 2003 URL: http://purl.umn.edu/23769
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Modélisation bioénergétique de la croissance, du développement et de la reproduction d'un petit pélagique : l'anchois du golfe de Gascogne ArchiMer
Pecquerie, Laure.
Understanding the recruitment variability of fish populations is a major challenge in fishery sciences. In the present work, we explore a new approach to study the potential factors that determine this recruitment in the context of biophysical modelling. The adult spawning pattern might influence the survival of the larvae as it determines the environmental conditions they experience during this critical period. We apply our study to the Bay of Biscay anchovy Engraulis encrasicolus, which is a multiple-batch spawner. The objective of the study is to understand the effect of the environmental conditions experienced by an individual i) on the energy available for reproduction and ii) on the temporal distribution of the spawning events and its consequences...
Tipo: Text Palavras-chave: Inter individual variability; Environmental scenarios; Link fish metabolism otolith; Larval survival; Spawning windows; Engraulis encrasicolus; Dynamic Energy Budget theory; Life cycle; Bioenergetic; Modelling; Variabilité inter individuelle; Scénarios environnementaux; Lien métabolisme otolithe; Survie larvaire; Fenêtres de ponte; Engraulis encrasicolus; Energy Budget; Théorie Dynamic; Cycle de vie; Bioénergétique; Modélisation.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/these-3505.pdf
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Modélisation de la détoxication de mollusques bivalves contenant des phycotoxines paralysantes ou diarrhéiques ArchiMer
Gueguen, Marielle.
The purpose of this study is to implement models to describe detoxification kinetics of Pacific oysters Crassostrea gigas and Blue mussels Mytilus edulis containing paralytic and diarrheic phycotoxins respectively. First, experimental trials made it possible to complement data from the literature regarding the understanding of processes involved in mollusc detoxification. In particular, they pointed out a difference in the mollusc capacity to degrade cellwalls of phycotoxin-producing dinoflagellates, according to their en cystement capacities. It was observed that paralytic phycotoxins reached the various oyster tissues whereas diarrheic toxins were mainly sequestred in the digestive gland of mussels. The latter seem to be retained by lysosomes localized...
Tipo: Text Palavras-chave: Modélisation; Mytilus edulis; Crassostrea gigas; Phycotoxines; Détoxication; Acide okadaïque; Toxines paralysantes; Modelling; Mytilus edulis; Crassostrea gigas; Phycotoxins; Detoxification; Okadaix acid; Paralytic toxin.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00003/11473/8032.pdf
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Modélisation de la dynamique du microphytobenthos des vasières intertidales du bassin de Marennes-Oléron. Effets des synchroniseurs physiques sur la régulation de la production ArchiMer
Guarini, Jean-marc.
The study aimed at quantifying the spatio-temporal evolution of microphytobenthic biomass in intertidal mudflats of Marennes-Oléron Bay. To reach this goal, a dynamic model has been proposed, including processes of primary production, active migration of epipelic diatoms and biomass lasses due to mortalities on one hand and resuspension in the water column during submersion on the other hand. The spatialisation is given by a hydrodynamic madel which calculates the water height everywhere. The photic environment of microphytobenthos is described in a discrete way, by means of two layers: the biofilm of epipelic algae « S »on the top of the sediment and the fust centimeter of the mud « F ». The endogenous vertical migration rhythm of epipelic algae controls...
Tipo: Text Palavras-chave: Microphytobenthos; Vasière intetidale; Modélisation; Dynamique de la biomasse; Expérimentation; Ecophysiologie; Couplage physique/biologie; Microphytobenthos; Intertidal mudflat; Modelling; Dynamics of the biomass; Experimentation; Ecophysiology; Physics/biology coupling.
Ano: 1998 URL: http://archimer.ifremer.fr/doc/00439/55029/56462.pdf
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Modélisation de l'affinage de l'huître Crassostrea gigas alimentée avec la diatomée Skeletonema costatum ArchiMer
Meleder, Vona; Barille-boyer, Anne-laure; Baud, Jean-pierre; Barille, Laurent; Cognie, Bruno; Rosa, Philippe.
The traditional fattening of the oyster Crassostrea gigas in oyster ponds of the French Atlantic Coast is submitted to natural environmental fluctuations. In order to reduce the growth variability of the soft parts of the bivalve, an intensive fattening process was developed, where the conditions of temperature, particulate organic and inorganic matter (POM and PIM) are controlled. This process relies on the production of the diatom Skeletonema costatum, which is then distributed to the oysters at an average concentration of 4–5 mg POM·L–1. An ecophysiological model of the oyster C. gigas, which simulates the evolution of somatic and gonad–reserve compartments, was applied to these conditions in order to analyse the bivalve responses. Experimentation was...
Tipo: Text Palavras-chave: Modélisation; Affinage; Ecophysiologie; Crassostrea gigas; Skeletonema costatum; Modelling; Oyster fattening; Ecophysiology; Crassostrea gigas; Skeletonema costatum.
Ano: 2001 URL: http://archimer.ifremer.fr/doc/00021/13248/10285.pdf
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Modélisation des cycles de l'azote et du phosphore dans les sédiments d'une lagune soumise à une exploitation conchylicole ArchiMer
Chapelle, Annie; Mesnage, Valérie; Mazouni, Nabila; Deslous-paoli, Jean-marc; Picot, Bernadette.
A simulation of nitrogen and phosphorus exchanges for the sediment-water interface is presented, The aim of the sttudy is to understand the dynamic behaviour of an eutrophie coastal lagoon (Thau, France), ln situ experiments were performed to estimate the different pools of nitrogen and phosphorus in the water column and in the sediment. The diffusive fluxes between them were also estimated. A numerical mode1, simulating nitrogen and phosphorus cycles, was developed and calibrated with data recorded .at two seasons (winter and summer). This study leads to the conclusion that is necessary to know the different pools of nitrogen and phosphorus in order to estimate which fraction is bioavailable and the rate of nutrient exchange between sediment and water. It...
Tipo: Text Palavras-chave: Modèle; Phosphore; Azote; Sédiment; Ecosystème conchylicole; Modelling; Phosphorus; Nitrogen; Sediment; Shellfish ecosystem.
Ano: 1994 URL: http://archimer.ifremer.fr/doc/00039/15026/12360.pdf
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Modélisation du transport particulaire dans le Golfe du Lion en vue d'une application au devenir des traceurs radioactifs issus du Rhône ArchiMer
Dufois, Francois.
Among the contaminants introduced into the environment, the artificial radionuclides appear particularly important to take into account because of their chemical toxicity and/or of their radiotoxicity. Some radionuclides present a high affinity with particles so that the study of the sediment dynamics is a useful preliminary to the study of their dispersion on the open sea. This thesis is focused on the fate of sediments in the Gulf of Lions (NW Mediterranean) and in particular on the impact of the Rhone River, which is the main source of particulate matter in the Gulf of Lions. In order to study the sediment transport mechanisms on various space and time scales, this thesis is based on mathematical modelling. The hydro-sedimentary model set up in the Gulf...
Tipo: Text Palavras-chave: Waves; MARS 3D; Hydrodynamic; Radionuclides; Modelling; Sediment; Rhône prodelta; Gulf of Lions; Vagues; MARS 3D; Hydrodynamique; Radioéléments; Modélisation; Sédiment; Prodelta du Rhône; Golfe du Lion.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/these-6308.pdf
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Modélisation du transport sédimentaire et des interactions morphodynamiques par les courants de turbidité dans les canyons sous-marins. Application à la Méditerranée Occidentale ArchiMer
Payo Payo, Marta.
Turbidity currents in submarine canyons are the main contribution for sediment transfer across the continental margins. Geological studies of submarine canyons and associated turbiditic systems for more than 30 years led to an extraordinary breakthrough in the understanding of how turbidite systems evolve. However, these studies remain limited to a posteriori interpretations, based on the distribution of deposits and morphological evidences. The overarching aim of this thesis is to apply a 2DH process-based model to simulate large-scale turbidity currents on two different submarine canyons in the western Mediterranean coast.The work in La Fonera canyon, in the Catalan margin, focuses on the modelling of sediment transport and accumulation resulting from...
Tipo: Text Palavras-chave: Canyons sous-marins; Chalutage; Courants de turbidité; Forces de Coriolis; Hydrodynamique; Modélisation; Sédimentologie; Submarine canyons; Trawling; Turbidity current; Modelling; Hydrodynamics; Sedimentology; Coriolis forces.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00498/60919/64280.pdf
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Modélisation et analyse numérique du couplage filet-écoulement hydrodynamique dans une poche de chalut ArchiMer
Pichot, Geraldine.
We are interested in the numerical simulation of the catch process at the end part of a trawl. The study of previous works emphasizes the lack of a convincing flow model. The need of a physical understanding of the flow leads us to perform experimental campaigns around a rigid cod-end net model, whose results are given in the manuscript. We propose a model based on the Navier-Stokes/Brinkman equations coupled to an equation for the turbulent kinetic energy by the means of an eddy viscosity, with appropriate boundary conditions. Existence of a weak solution to our coupled problem is proved in dimension 2. Then, we present the axisymmetric code we developed, called SeaNet. We set the parameters of the model and validate the code by comparison with the...
Tipo: Text Palavras-chave: Finite Element Method; Numerical simulations; Variational formulations; Modelling; Fluid/structure interactions; Turbulence; Fluid mechanics; Selectivity of fishing gear; Méthode des éléments finis; Simulations numériques; Formulations variationnelles; Modélisation; Intéractions fluide/structure; Turbulence; Mécanique des fluides; Sélectivité des engins de pêche.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/these-3350.pdf
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Modelisation morphodynamique de l'embouchure de la seine ArchiMer
Waeles, Benoit.
The mouth of the Seine has been undergoing intense morphological changes for decades, because of containment work to improve access to the ports of Rouen and Le Havre. A significant trend is the progradation of the downstream estuary. Simultaneously, the surface area of the intertidal mudflats tends to decrease. The estuary's sediments are composed of silt and fine sand (respectively transported from the river Seine and the open sea). Their distribution is linked to the hydrodynamic characteristics of the estuary and may display layered vertical structures. To understand the estuary's morphological changes, a morphodynamic ditigal model is developed from a validated (3D) model of silty sediment transport. A model of suspended fine sand transport as well as...
Tipo: Text Palavras-chave: Seine estuary; Modelling; Sediment transport; Hydrodynamic; Morphodynamic; Seine estuaire; Modelisation; Transport sediment; Hydrodynamique; Morphodynamique.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/these-2195.pdf
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Modélisation morphodynamique d'une embouchure tidale : Application aux Passes d'entrée du Bassin d'Arcachon ArchiMer
Cayocca, Florence.
The Arcachon tidal inlet exhibits a particularly active morphology due to strong tidal currents and rough wave conditions. During the past 300 years, maximum and minimum extents of the Cap Ferret sand spit have resulted in a difference of 8 km while two channels have alternatively allowed circulation between the lagoon and the ocean. A bidimensional horizontal morphodynarnic model was developed in order to simulate the system evolution under tidal forcing alone or under combined tide and wave action. Modelling at a scale of decades requires the definition of mean annual wave and tide conditions which are representative with respect to sediment transport. Medium term results thus give general trends of evolution. Driven by these average conditions and...
Tipo: Text Palavras-chave: Littoral drift; Sediment transport; Tide; Waves; Arcachon lagoon; Tidal inlet; Modelling; Morphodynamic; Dérive littorale; Transport sédimentaire; Marée; Houle; Bassin d'Arcachon; Modèle; Morphodynamique.
Ano: 1996 URL: http://archimer.ifremer.fr/doc/1996/these-4520.pdf
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Modelisation numerique du flambage de panneaux sandwich raidis ArchiMer
Batoz, J; Quesnel, T.
This paper presents a numerical method for the buckling analysis of stiffened sandwich panels for ship building with composite materials. The formulation of a multi-layered quadrilateral finite element of a plane shell including transverse shear effects is presented. Some classical tests allow the performance of this element to be evaluated for composite plates. Then an explanation is given for a method used for analyzing the buckling of panels.
Tipo: Text Palavras-chave: Ship technology; Composite materials; Modelling; Mathematical models; Numerical analysis; Eléments finis; Plaque coque; Flambage; Structure sandwich; Matériau composite.
Ano: 1992 URL: http://archimer.ifremer.fr/doc/1992/acte-1074.pdf
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Modelling abrupt glacial North Atlantic freshening: Rates of change and their implications for Heinrich events ArchiMer
Bigg, Grant R.; Levine, Richard C.; Green, Clare L..
The abrupt delivery of large amounts of freshwater to the North Atlantic in the form of water or icebergs has been thought to lead to significant climate change, including abrupt slowing of the Atlantic Ocean meridional overturning circulation. In this paper we examine intermediate complexity coupled modelling evidence to estimate the rates of change, and recovery, in oceanic climate that would be expected for such events occurring during glacial times from likely sources around the North Atlantic and Arctic periphery. We show that rates of climate change are slower for events with a European or Arctic origin. Palaeoceanographic data are presented to consider, through the model results, the origin and likely strength of major ice-rafting, or Heinrich,...
Tipo: Text Palavras-chave: Heinrich events; Modelling; Quaternary; Icebergs.
Ano: 2011 URL: https://archimer.ifremer.fr/doc/00227/33777/82665.pdf
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Modelling Climate Change and Agricultural Production in Sub-Saharan Africa (SSA): In Quest of Statistics AgEcon
Koffi-Tessio, Egnonto M..
Climate change is a natural and dynamic phenomenon resulting from complex interrelationships between physical, environmental and human factors. The sustainability of life on earth depends partly on the ability of mankind to maintain this natural and balanced flow of such gases such as carbon dioxide (CO2) and water vapor traping heat. Unfortunately, human beings contribute significantly to the presence of such gases known as Green House Gases (GHGs) through agricultural and industrial activities. The implications are the excess trap of sunlight and the blocking of outward radiation. In sub-Saharan Africa (SSA), the importance of agriculture cannot be stressed enough given that it is central to economic growth and most of economic activities in the region...
Tipo: Conference Paper or Presentation Palavras-chave: Modelling; Agriculture; Climate change; Variability; Statistics; Policies; Environmental Economics and Policy; Farm Management.
Ano: 2009 URL: http://purl.umn.edu/50821
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Modelling growth and reproduction of the Pacific oyster Crassostrea gigas: Advances in the oyster-DEB model through application to a coastal pond ArchiMer
Bourles, Yves; Alunno-bruscia, Marianne; Pouvreau, Stephane; Tollu, Guillaume; Leguay, Didier; Arnaud, Christophe; Goulletquer, Philippe; Kooijman, S.
A bio-energetic model, based on the DEB theory exists for the Pacific oyster Crassostrea gigas. Pouvreau et al. [Pouvreau, S., Bourles, Y., Lefebvre, S., Gangnery, A., Alunno-Bruscia, M., 2006. Application of a dynamic energy budget model to the Pacific oyster, C. gigas, reared under various environmental conditions. J. Sea Res. 56, 156–167.] successfully applied this model to oysters reared in three environments with no tide and low turbidity, using chlorophyll a concentration as food quantifier. However, the robustness of the oyster-DEB model needs to be validated in varying environments where different food quantifiers reflect the food available for oysters, as is the case in estuaries and most coastal ecosystems. We therefore tested the oyster-DEB...
Tipo: Text Palavras-chave: Coastal Environment; Temperature effect; Food Quantifiers; Crassostrea gigas; Bivalves; Modelling; DEB theory.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6436.pdf
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MODELLING IMPACTS OF SOME EUROPEAN BIOFUEL MEASURES AgEcon
Ledebur, Oliver von; Salamon, Petra; Zimmermann, Andrei; van Leeuwen, Myrna; Tabeau, Andrzej A.; Chantreuil, Frederic.
Against the background of increasing concerns regarding the energy supply security as well as environmental concern the interest for renewable energy sources has increased in recent years. The biofuel sector, backed by public policies, experienced a strong increase in and outside Europe. A methodology that allows for the estimation of the impacts of the fulfilment of the proposed biofuel targets in the EU member states is proposed and implemented in the AGMEMOD model for France and Germany. The so called normative approach, based on the use of a logistic function as biofuel demand function allows to perform simulations to assess the impact of the biofuel demand expansion on agricultural markets. The implemented approach and the simulation results indicate...
Tipo: Conference Paper or Presentation Palavras-chave: Biofuel targets; Biodiesel; Ethanol; Modelling; Crop Production/Industries; Public Economics; Resource /Energy Economics and Policy.
Ano: 2008 URL: http://purl.umn.edu/6649
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Modelling larval dispersal and settlement of the reef-building polychaete Sabellaria alveolata: Role of hydroclimatic processes on the sustainability of biogenic reefs ArchiMer
Ayata, Sakina-dorothee; Ellien, Celine; Dumas, Franck; Dubois, Stanislas; Thiebaut, Eric.
The honeycomb worm Sabellaria alveolata forms biogenic reefs which constitute diversity hotspots on tidal flats. The largest known reefs in Europe, located in the Bay of Mont-Saint-Michel (English Channel), are suffering increasing anthropogenic disturbances which raise the question of their sustainability. As the ability to recover depends partly on the recolonization of damaged reefs by larval supply, evaluating larval dispersal and the connectivity between distant reefs is a major challenge for their conservation. In the present study, we used a 3D biophysical model to simulate larval dispersal under realistic hydroclimatic conditions and estimate larval retention and exchanges among the two reefs of different sizes within the bay. The model takes into...
Tipo: Text Palavras-chave: Bay of Mont Saint Michel; English Channel; Modelling; Larval settlement; Larval transport; Connectivity; Biogenic reefs; Sabellaria alveolata.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6841.pdf
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