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Registros recuperados: 41 | |
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Orsini, Nicola; Bellocco, Rino; Bottai, Matteo; Wolk, Alicja; Greenland, Sander. |
Classification errors, selection bias, and uncontrolled confounders are likely to be present in most epidemiologic studies, but the uncertainty introduced by these types of biases is seldom quantified. The authors present a simple yet easy-to-use Stata command to adjust the relative risk for exposure misclassification, selection bias, and an unmeasured confounder. This command implements both deterministic and probabilistic sensitivity analysis. It allows the user to specify a variety of probability distributions for the bias parameters, which are used to simulate distributions for the bias-adjusted exposure–disease relative risk. We illustrate the command by applying it to a case–control study of occupational resin exposure and lung-cancer deaths. By... |
Tipo: Article |
Palavras-chave: Episens; Episensi; Sensitivity analysis; Unmeasured confounder; Misclassification; Bias; Epidemiology; Research Methods/ Statistical Methods. |
Ano: 2008 |
URL: http://purl.umn.edu/120927 |
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Drouineau, Hilaire; Mahevas, Stephanie; Pelletier, Dominique; Beliaeff, Benoit. |
In this paper, we present an approach to compare the impact of different management options oil the dynamics of a mixed fishery. We used ISIS-Fish, a simulation tool aimed at evaluating the impact of spatial and seasonal management measures on the dynamics of mixed fisheries. The French Nephrops norvegicus (Norway lobster) Merluccius merluccius (hake) mixed fishery of the Bay of Biscay was chosen as a Study case. First, we parameterised the Population and exploitation models. We then selected several management measures, including marine protected fishermen's reaction to each measure. Then, a sensitivity analysis (MPAs) and total allowable catches (TAC), and parameterised fish sensitivity analysis was performed according to a fractional factorial... |
Tipo: Text |
Palavras-chave: Simulation design; Sensitivity analysis; Management measures; Spatial model; Fisheries dynamics. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1340.pdf |
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Drouineau, Hilaire; Mahevas, Stephanie; Bertignac, Michel; Fertin, A. |
Most of the traditional assessment models are age-structured. However, many biological and exploitation processes are more length-dependent than age-dependent, and the required length-age conversion of available data is often not reliable. Consequently, length-structured or age-length structured models have undergone considerable development in recent years. The growth transition matrix used to model the mean growth and growth variability of the population, is of primary importance in a length-structured matrix model. Building this growth transition matrix is not trivial and it is necessary to assess the impact that various assumptions may have to identify robust model structures. In this study, we assess the effects of (1) time and length discretisation,... |
Tipo: Text |
Palavras-chave: Sensitivity analysis; Discrete model; Growth; Length structured model. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4301.pdf |
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Mello,Renius; Resende,Flávio Dutra de; Queiroz,Augusto César de; Faria,Marcelo Henrique de; Oliveira,André Soares de; Siqueira,Gustavo Rezende. |
The objective in this work was to evaluate the economicity of the finishing phase on feedlot of F1 Red Angus × Nellore (½ RA ½ N) and Blond D'Aquitaine × Nellore (½ BA ½ N) crossbred young bulls slaughtered at 480, 520 and 560 kg of body weight. Thirty-six F1 crossbred young bull with 20 months of initial average age: 18 ½RA½ N and 18 ½N½ BA were allotted to a completely randomized design in a 2 × 3 factorial arrangement (genetic group × slaughter weight), with six replicates. The ½ BA ½ N young bulls slaughtered at 480 kg had the highest carcass gain (kg/day), feed efficiency, gross income (R$/day), gross profit of feed (R$/day), break-even cost of the diet (@/t DM) and cost:benefit ratio. The ½ BA ½ N young bulls also had higher dressing percentage than... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Bioeconomic analysis; Economic feasibility; Profitability; Sensitivity analysis. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982009000100015 |
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Degre, Delphine; Leguerrier, D; Du Chatelet, E; Rzeznik, J; Auguet, Jean-christophe; Dupuy, Christine; Marquis, E; Fichet, Denis; Struski, Caroline; Joyeux, E; Sauriau, Pierre-guy; Niquil, Nathalie. |
Inverse analysis was used to model the food webs of two intertidal mudflat ecosystems: Aiguillon Cove (AC) and Brouage Mudflat (BM) (south-western Atlantic coast, France). The aim of the present study is to describe and compare the functioning of these two ecosystems. The method of inverse analysis has been adapted in order to take into account, in a single calculation, two seasons: spring/summer (mid-March to mid-October) and autumn/winter (the rest of the year). Gathering all available data on the two sites, the most important gaps in knowledge were identified with the help of sensitivity analyses: they concerned mainly the exports of material by grazing fish (such as mullet Liza ramada), resuspension of microphytobenthos, and fluxes linked to microfauna... |
Tipo: Text |
Palavras-chave: Atlantic coast; Sensitivity analysis; Tidal flat; Inverse analysis; Steady state; Food web. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1863.pdf |
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Lips, Markus; Rieder, Peter. |
This paper discusses an approach to implement output quotas in the GTAP model which permits an endogenous adjustment of both the supplied quantity and the quota rent. Since the quota rent is interpreted as additional earnings of the factors used no change of the worldwide GTAP data base is required. Several modifications of the GTAP model and two exogenous coefficients are necessary. Considering uncertain values of one of the coefficients, systematic sensitivity analysis is applied. The abolishment of the raw milk quota in the European Union would lead to a remarkable decrease in raw milk prices in most member countries. The raw milk production increases in Denmark, Ireland, Luxembourg and the Netherlands while it declines in Greece and Portugal. In the... |
Tipo: Conference Paper or Presentation |
Palavras-chave: General equilibrium model; GTAP; Output quota; Raw milk production; Sensitivity analysis; Agribusiness. |
Ano: 2002 |
URL: http://purl.umn.edu/24817 |
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Niquil, Nathalie; Kerleguer, G; Leguerrier, D; Richard, Pierre; Legrand, Helene; Dupuy, Christine; Pascal, P; Bacher, Cedric. |
The presence of herbicides in the run-off water coming over Brouage mudflat (Marennes-Oleron Bay, France) is suspected to cause a loss of primary production by benthic diatom biofilm. Microphytobenthos being the main primary producer of this ecosystem, it was questioned about what could be the effect of such a modification of primary production on the entire food web that depends on it. The probable impacts were investigated through a sensitivity analysis conducted on the steady-state model of the Brouage mudflat, coupling two seasons and trophic-hydrodynamic flows. The loss of benthic primary production had an effect on compartments at a low trophic level, but was buffered at higher levels because of the compensation of herbivory by other pathways and... |
Tipo: Text |
Palavras-chave: Intertidal mudflat food web; Pollution; Microphytobenthos; Inverse analysis; Sensitivity analysis. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3613.pdf |
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Jha, Manoj K.. |
This paper describes the application of the Soil and Water Assessment Tool (SWAT) model to the Maquoketa River watershed, located in northeast Iowa. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). Climatic data from six weather stations located in and around the watershed, and measured streamflow data from a U.S. Geological Survey gage station at the watershed outlet were used in the sensitivity analysis of SWAT model parameters as well as its calibration and validation for watershed hydrology and streamflow. A sensitivity analysis was performed using an influence coefficient method to evaluate surface... |
Tipo: Working or Discussion Paper |
Palavras-chave: Calibration and validation; Hydrologic simulation; Sensitivity analysis; SWAT.; Environmental Economics and Policy. |
Ano: 2009 |
URL: http://purl.umn.edu/51123 |
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Registros recuperados: 41 | |
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