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| Registros recuperados: 8.909 | |
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| Ribeiro,L.A.; Mariani,P.D.S.C.; Azevedo,J.L.; Rech,E.L.; Schmidt,G.S.; Coutinho,L.L.. |
| Chicken embryos kept in culture medium were bombarded using a high helium gas pressure biolistic device. To optimize the factors that affect transformation efficiency, the lacZ gene under control of the human cytomegalovirus immediate early enhancer/promoter was used as a reporter gene. There was an inverse relationship between survival rate and transformation efficiency. The best conditions obtained for high embryo survival and high transformation efficiency were achieved with 800 psi helium gas pressure, 500 mmHg vacuum, gold particles, an 8 cm DNA-coated microparticle flying distance to the embryo and embryo placement 0.5 cm from the center of the particle dispersion cone. Under these conditions, transformation efficiency was 100%, survival rate 25% and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biolistic process; Chicken embryo; Gene transfer; SS-galactosidase; Green fluorescent protein; GFP. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000900003 |
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| Erickson, Jon D.; Schlapfer, Felix. |
| Agronomists consider the continuity and nutrient capturing properties of cover crops as important determinants of nutrient cycling in agricultural systems. Managing for these biotic control functions can help limit nutrient loss and groundwater contamination between main crop harvests. This simulation study highlights the potential role of cover crop management in a welfare economics framework. The objective is to find the optimal combination of nutrient input to the main crop, the extent of off-season cover crops, and crop functional diversity to maximize the sum of benefits from agricultural production and groundwater protection. |
| Tipo: Journal Article |
Palavras-chave: Crop Production/Industries. |
| Ano: 2001 |
URL: http://purl.umn.edu/31422 |
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| Lanfranco, Bruno A.; Ames, Glenn C.W.; Huang, Chung L.. |
| A system of nine censored Engel curve equations was estimated for Hispanic households in the U.S.: grains, vegetables, fruits, milk, meat, legumes, fats, sugar, and beverages. Income and household size elasticities, with their respective confidence intervals, are reported and the results compared with other ethnic groups in the U.S. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Food Consumption/Nutrition/Food Safety. |
| Ano: 2001 |
URL: http://purl.umn.edu/16720 |
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| Lofgren, Hans. |
| Computable General Equilibrium (CGE) models are a class of economywide models that are widely used for policy analysis in developing countries. This paper provides a detailed documentation of an applied CGE model of Malawi the first ever for Malawi developed in the context of the project Collaborative Research and Capacity Strengthening for Multi-Sector Policy Analysis in Malawi and Southern Africa. The purpose of this paper is to serve as a source of background information for analysts using the model in the context of the current project and in the future. The model is built around a 1998 Social Accounting Matrix (SAM) for Malawi, which was developed in the context of the current project, is based on data from the 1998 Integrated Household Survey... |
| Tipo: Working or Discussion Paper |
Palavras-chave: International Development. |
| Ano: 2001 |
URL: http://purl.umn.edu/16264 |
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| Queiroz Sousa,Maria de Fátima Vieira de; Lopes,Carlos Edison; Pereira Júnior,Nei. |
| A chemically defined medium consisting of D(+)fructose, L(-)threonine, K2HPO4, MgSO4.7H2O, ZnSO4.7H2O, CaCl2.2H2O, FeSO4.7H2O and deionized water, was developed to maximize the synthesis of actinomycin D by the Streptomyces parvulus DAUFPE 3124 strain. This medium resulted in the maximum antibiotic concentration of 133mg/L while using the original medium the production of actinomycin D was poor not surpassing 43mg/L. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Actinomycin D; Production; Streptomyces. parvulus; Synthetic medium. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000300002 |
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| Martin, Larry J.; Stiefelmeyer, Kate. |
| This study starts with three objectives: a. to revisit and revise, if necessary, the definition of competitiveness and characterize the factors that affect relative competitiveness. b. To apply the definition of competitiveness empirically by measuring labour productivity, as well as value-added for industries in the agri-food sector in Canada and the US. c. To assess and describe changes in agri-food sector competitiveness over time |
| Tipo: Working or Discussion Paper |
Palavras-chave: Productivity Analysis. |
| Ano: 2001 |
URL: http://purl.umn.edu/18098 |
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| Olivella,Mónica S.; Zarelli,Valeria E.P.; Pappano,Nora B.; Debattista,Nora B.. |
| Among other properties, flavonoids present a notable bacteriostatic activity. In this paper, minimal inhibitory concentrations (MICs) of 5,7,4'-trihydroxyflavanone (naringenin), 5,7-dihydroxyflavone and 2',4',4- trihydroxychalcone (isoliquitirigenin) against Staphylococcus aureus ATCC 25 923 were determined and compared to values obtained for other chalcones and flavanones previously investigated. Specific growth rates and MICs were determined by a turbidimetric kinetic method. The observed sequence MICflavanone (inactive) >MIC7-hidroxyflavanone (197.6 µgml-1)>MIC5,7,4'-trihydroxyflavanone (120 µgml-1) showed that the introduction of an electron donating group (-OH) causes an increase in bioactivity. On the other hand, the comparisons... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Flavanone; Flavone; Chalcone; Bacteriostatic activity. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822001000300013 |
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| Van der Lingen, C.D.; Kreiner, A.; Fréon, P.. |
| Time-series of condition factor (CF) and gonadosomatic index (GSI) were generated using general linear models (GLM) for sardine Sardinops sagax stocks in the northern and southern Benguela ecosystems over the period 1984–1999. During this period the biomass of sardine in the northern Benguela remained at relatively low levels of <500 000 tons, whereas that of southern Benguela sardine increased 40-fold to 1.3 million tons. The GLMs explained 27 and 45% of the observed variation in CF, and 32 and 28% of the observed variation in GSI, for sardine in the northern and southern Benguela subsystems respectively. Whereas the sardine CF in the northern Benguela remained stable over time, that for the southern Benguela stock declined steadily during the study... |
| Tipo: Journal Contribution |
Palavras-chave: Abstracts; Ecosystems; Sardine fisheries; Ecosystems; Http://aims.fao.org/aos/agrovoc/c_2482. |
| Ano: 2001 |
URL: http://hdl.handle.net/1834/2124 |
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| Ducet, N; Le Traon, Pierre-yves. |
| Analyses of surface eddy kinetic energy (EYE) inferred from 5 years of merged TOPEX/Poseidon and ERS-1/2 altimetric data are presented in the Gulf Stream (GS) and the Kuroshio (KS) Current systems, focusing on anisotropy and EKE seasonal, interannual, and long-term variations, as well as Reynolds stresses. For both GS and KS a descriptive analysis of the EKE field shows that it is anisotropic along the path of the currents and assesses the close relationship between the spatial distribution of EKE high levels and bottom topography. A striking ocean feature is found in the GS, shaped as a zonal "double-blade" structure in the EKE field, centered at 37 degrees N, 71.5 degrees W, that likely corresponds to a regular and permanent lateral displacement of the... |
| Tipo: Text |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00084/19476/17095.pdf |
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| Harris, Rebecca Lee. |
| Since the late 1980s, Mexico has liberalized its agricultural sector, moving from a system of price supports, producer subsidies and consumer subsidies to a less distorting scheme in which market forces play a greater role. Coinciding with these agrarian and food policy reforms, the government has implemented the PROCAMPO system of direct payments to farmers. There is a general consensus that a direct payment program has the potential to be more efficient than a system of subsidies and supports. At the same time, there is widespread agreement that other policies need to be put in place to assure protection of the economically vulnerable segments of the population. Within this context, this paper uses a computable general equilibrium (CGE) model to analyze... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Agricultural and Food Policy. |
| Ano: 2001 |
URL: http://purl.umn.edu/16271 |
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| Registros recuperados: 8.909 | |
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