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Registros recuperados: 112 | |
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Johnson, Fred; U.S. Fish and Wildlife Service; fred_a_johnson@fws.gov; Williams, Ken; ; byron_ken_williams@nbs.gov. |
Waterfowl harvest management in North America, for all its success, historically has had several shortcomings, including a lack of well-defined objectives, a failure to account for uncertain management outcomes, and inefficient use of harvest regulations to understand the effects of management. To address these and other concerns, the U.S. Fish and Wildlife Service began implementation of adaptive harvest management in 1995. Harvest policies are now developed using a Markov decision process in which there is an explicit accounting for uncontrolled environmental variation, partial controllability of harvest, and structural uncertainty in waterfowl population dynamics. Current policies are passively adaptive, in the sense that any reduction in structural... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Adaptive management; Harvest; Hunting regulations; Markov decision process; Migratory birds; Optimization; Uncertainty; Waterfowl.. |
Ano: 1999 |
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Lu,Jike; Song,Qi; Ji,Zhenyu; Liu,Xin; Wang,Ting; Kang,Qiaozhen. |
Background The fermentation conditions of recombinant maltose-binding protein fused to neutrophil-activating protein (rMBP-NAP) of Helicobacter pylori were optimized from Escherichia coli TB1 with varying medium, inoculum age and size, time, inducer, pH and temperature in batch fermentation. Results It was revealed that the optimal conditions for the production of rMBP-NAP in shake flask were as follows: M9 medium (with 3% yeast extract powder added), inoculum age of 19 h, inoculum size of 6%, initial pH of 6.6, temperature of 37°C, and 0.7 mmoL/L IPTG inducted 21 h in a 50 mL/250 mL shake flask. The recombinant protein yield was increased from 59 to 592 mg/L after optimization. Fermentation process conducted in a 10 L fermenter with similar conditions... |
Tipo: Journal article |
Palavras-chave: Escherichia coli; Fermentation; Optimization; Recombinant protein. |
Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000400004 |
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León-Anzueto,Elizabeth; Abud-Archila,Miguel; Dendooven,Luc; Ventura-Canseco,Lucía María Cristina; Gutiérrez-Miceli,Federico A. |
The objective of this study was to investigate the effect of vermicompost, worm-bed leachate (WBL) and Glomus mosseae, an arbuscular mycorrhizal fungi (AMF), on growth of lemongrass (Cymbopogon citratus (DC.) Stapf). A response surface methodology, i.e. a three-level Box Benhen design with three repetitions and three blocks, was applied to optimize biomass production, essential oil yield and its composition. Application rates of Glomus mosseae were 0, 1 or 2 g plant-1, vermicompost 0, 5 or 10 g plant-1 and WBL 0, 10 and 20%. The AMF had no significant effect on the variables tested, but vermicompost had a significant effect on essential oil yield and WBL on essential oil yield, myercene concentration and shoot dry weigh (p < 0.05). It was found that... |
Tipo: Journal article |
Palavras-chave: Citral; Desirability function; Lemongrass; Myrcene; Optimization; Response surface methodology. |
Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000600005 |
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Sangkharak,Kanokphorn; Prasertsan,Poonsuk. |
Three halotolerant bacterial strains; Rhodobacter sphaeroides ES16 (the wild type) and the two mutant strains of R. sphaeroides ES16, namely N20 and U7, were cultivated in glutamate-malate (GM) medium and screened for production of polyhydroxybutyrate (PHB). The mutant strains N20 and U7 were found to accumulate PHB (53.9 and 42.0% of DCW, respectively) 3.6 and 2.8 times higher than the wild type strain (19.5% of DCW), respectively. R. sphaeroides N20 were selected for studies on the effects of nutrient and environmental conditions on PHB accumulation. The optimal condition was 4 g/l acetate, 0.02 g/l (NH4)2SO4, C/N ratio of 6:1, 1.0 g/l K2HPO4, 1.0 g/l KH2PO4 and 3% NaCl with initial pH at 7.0. Under this optimal condition, the maximum PHB accumulation... |
Tipo: Journal article |
Palavras-chave: Aerobic-dark cultivation; Optimization; PHB; Polyhydroxybutyrate; Rhodobacter sphaeroides. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000300009 |
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Guedes,Luciana P. C.; Ribeiro Junior,Paulo J.; Uribe-opazo,Miguel A.; Bastiani,Fernanda de. |
ABSTRACT This study aimed to compare thematic maps of soybean yield for different sampling grids, using geostatistical methods (semivariance function and kriging). The analysis was performed with soybean yield data in t ha-1 in a commercial area with regular grids with distances between points of 25x25 m, 50x50 m, 75x75 m, 100x100 m, with 549, 188, 66 and 44 sampling points respectively; and data obtained by yield monitors. Optimized sampling schemes were also generated with the algorithm called Simulated Annealing, using maximization of the overall accuracy measure as a criterion for optimization. The results showed that sample size and sample density influenced the description of the spatial distribution of soybean yield. When the sample size was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Accuracy indices; Optimization; Sampling grids; Spatial variability. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100114 |
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Dall'Igna Júnior,Alcino; Silva,Renato S.; Mundim,Kleber C.; Dardenne,Laurent E.. |
The main goal of this study is to find the most effective set of parameters for the Simplified Generalized Simulated Annealing algorithm, SGSA, when applied to distinct cost function as well as to find a possible correlation between the values of these parameters sets and some topological characteristics of the hypersurface of the respective cost function. The SGSA algorithm is an extended and simplified derivative of the GSA algorithm, a Markovian stochastic process based on Tsallis statistics that has been used in many classes of problems, in particular, in biological molecular systems optimization. In all but one of the studied cost functions, the global minimum was found in 100% of the 50 runs. For these functions the best visiting parameter, qV,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Optimization; Generalized simulated annealing. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000400024 |
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Khaled, Ramez; Priour, Daniel; Billard, Jean-yves. |
A numerical method for optimization of the cable lengths in trawls with respect to the ratio between the estimated trawl drag and the predicted catch efficiency is developed and applied. The trawl cables of interest are warps, bridles, headline and footrope. The optimization algorithm applies an ordered sequential process changing one cable length at the time. It is assumed in the predictions that the catch efficiency of the trawl is proportional with the trawl mouth area. In a case study optimizing a bottom trawl used on a research vessel by applying the new method it is predicted that it would be possible to reduce the ratio between trawl drag and catch efficiency by up to 46% by optimizing the cable lengths. Thus this would enable a considerable... |
Tipo: Text |
Palavras-chave: Bottom trawl; Modeling; Optimization; Fuel consumption; Drag; Swept area; Mouth surface; Fish distribution. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00130/24106/22857.pdf |
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Brillet-viel, Anne; Pilet, Marie-france; Courcoux, Philippe; Prevost, Hervé; Leroi, Francoise. |
Optimization of Carnobacterium divergens V41 growth and bacteriocin activity in a culture medium deprived of animal protein, needs for food bioprotection, was performed by using a statistical approach. In a screening experiment, twelve factors (pH, temperature, carbohydrates, NaCl, yeast extract, soy peptone, sodium acetate, ammonium citrate, magnesium sulphate, manganese sulphate, ascorbic acid and thiamine) were tested for their influence on the maximal growth and bacteriocin activity using a two-level incomplete factorial design with 192 experiments performed in microtiter plate wells. Based on results, a basic medium was developed and three variables (pH, temperature and carbohydrates concentration) were selected for a scale-up study in bioreactor. A... |
Tipo: Text |
Palavras-chave: Optimization; Carnobacterium; Bacteriocin; Experimental design; Bioreactor; Growth; Cold-smoked salmon. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00345/45615/45236.pdf |
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Donis, Daphne; Holtappels, Moritz; Noss, Christian; Cathalot, Cecile; Hancke, Kasper; Polsenaere, Pierre; Wenzhoefer, Frank; Lorke, Andreas; Meysman, Filip J. R.; Glud, Ronnie N.; Mcginnis, Daniel F.. |
The quantification of benthic fluxes with the aquatic eddy correlation (EC) technique is based on simultaneous measurement of the current velocity and a targeted bottom water parameter (e.g., O2, temperature). High-frequency measurements (64 Hz) are performed at a single point above the seafloor using an acoustic Doppler velocimeter (ADV) and a fast-responding sensor. The advantages of aquatic EC technique are that 1) it is noninvasive, 2) it integrates fluxes over a large area, and 3) it accounts for in situ hydrodynamics. The aquatic EC has gained acceptance as a powerful technique; however, an accurate assessment of the errors introduced by the spatial alignment of velocity and water constituent measurements and by their different response times is... |
Tipo: Text |
Palavras-chave: Turbulence; Boundary layer; Fluxes; Instrumentation/sensors; Optimization; Experimental design. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38577/37102.pdf |
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Ayata, S. -d.; Levy, Marina; Aumont, Olivier; Sciandra, Antoine; Sainte-marie, J.; Tagliabue, A.; Bernard, Olivier. |
The aim of this study is to evaluate the consequences of accounting for variable Chl:C (chlorophyll:carbon) and C:N (carbon:nitrogen) ratios in the formulation of phytoplankton growth in biogeochemical models. We compare the qualitative behavior of a suite of phytoplankton growth formulations with increasing complexity: 1) a Redfield formulation (constant C:N ratio) without photo-acclimation (constant Chl:C ratio), 2) a Redfield formulation with diagnostic chlorophyll (variable and empirical Chl:C ratio), 3) a quota formulation (variable C:N ratio) with diagnostic chlorophyll, and 4) a quota formulation with prognostic chlorophyll (dynamic variable). These phytoplankton growth formulations are embedded in a simple marine ecosystem model in a 1D framework... |
Tipo: Text |
Palavras-chave: Biogeochemical modeling; Phytoplankton; Photo-acclimation; Redfield ratio; Internal quota; BATS; Optimization; Micro-genetic algorithm. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00159/27071/25460.pdf |
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Vasseur, Christophe; Bougaran, Gael; Garnier, Matthieu; Hamelin, Jérôme; Leboulanger, Christophe; Le Chevanton, Myriam; Mostajir, Behzad; Sialve, Bruno; Steyer, Jean-philippe; Fouilland, Eric. |
Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae–bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate)... |
Tipo: Text |
Palavras-chave: Optimization; Nannochloris; Heterotrophic bacteria; Anaerobic digestion; Bioenergy. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00085/19642/17419.pdf |
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Messager, Tanguy; Chauchot, Pierre; Bigourdan, Benoit. |
This numerical study deals with the stiffened composite underwater vessel design. The structures under investigation are laminated cylinders with rigid end-closures and inter-nal circumferential and longitudinal unidirectional composite stiffeners. Structural buckling induced by the high external hydrostatic pressure is considered as the major failure risk. An optimization design tool has been developed to obtain the reinforcement definition which maximizes the limit of stability: an analytical model of cylindrical composite shell buckling has been coupled to a genetic algorithm procedure. The numerical optimization tests carried out corroborate design tendencies validated previously by experiments. |
Tipo: Text |
Palavras-chave: Optimization; Buckling; Stiffeners; Cylinders; Composite. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-6474.pdf |
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Robinson, John R.C.; Michelsen, Ari M.; Gollehon, Noel R.. |
This study extends and refines a previous model and provides estimates of the economic value of water shortages from shortfalls in Mexican deliveries to the U.S. In the process, we identify and evaluate a range of crop choices, appropriate irrigation technology use, water source substitution, and other mitigation strategies used by farmers to deal with water shortages. The effects of exogenous crop price and yield risk, as well as and other structural considerations are incorporated in deriving the marginal value of irrigation water for reference drought years. Results show that South Texas farmers react to risk by diversifying their crop mix, which in turn has implications for the imputed value of water and soil resources. The derived shadow price of... |
Tipo: Conference Paper or Presentation |
Palavras-chave: Water; Irrigation; Rio Grande; Optimization; Resource /Energy Economics and Policy. |
Ano: 2005 |
URL: http://purl.umn.edu/19464 |
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Registros recuperados: 112 | |
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