3,816 research outputs found
Assessing Oligopoly and Oligopsony Power in the U.S. Catfish Industry
This paper addresses the issue of competition in the U.S. catfish industry. To this end, a conjectural variation oligopolistic model was developed. The model was estimated econometrically using the Generalized Method of Moments (GMM) procedure. Chi-square analysis implied that catfish processors do not exert market power over farmers or over consumers. The conjectural elasticity was estimated to be 0.073, the oligopoly power index 0.28, and the oligopsony power index 0.68, and none of these values were statistically significant. The results support competitive behavior of the catfish processing sector.competition, conjectural variation model, U.S. catfish industry, Agribusiness, Livestock Production/Industries,
Nano and viscoelastic Beck's column on elastic foundation
Beck's type column on Winkler type foundation is the subject of the present
analysis. Instead of the Bernoulli-Euler model describing the rod, two
generalized models will be adopted: Eringen non-local model corresponding to
nano-rods and viscoelastic model of fractional Kelvin-Voigt type. The analysis
shows that for nano-rod, the Herrmann-Smith paradox holds while for
viscoelastic rod it does not
Architectures for block Toeplitz systems
In this paper efficient VLSI architectures of highly concurrent algorithms for the solution of block linear systems with Toeplitz or near-to-Toeplitz entries are presented. The main features of the proposed scheme are the use of scalar only operations, multiplications/divisions and additions, and the local communication which enables the development of wavefront array architecture. Both the mean squared error and the total squared error formulations are described and a variety of implementations are given
Cluster Development and Knowledge Exchange in Supply Chain
Industry cluster and supply chain are in focus of every countries which rely
on knowledge-based economy. Both focus on improving the competitiveness of firm
in the industry in the different aspect. This paper tries to illustrate how the
industry cluster can increase the supply chain performance. Then, the proposed
methodology concentrates on the collaboration and knowledge exchange in supply
chain. For improving the capability of the proposed methodology, information
technology is applied to facilitate the communication and the exchange of
knowledge between the actors of the supply chain within the cluster. The supply
chain of French stool producer was used as a case study to validate the
methodology and to demonstrate the result of the study
Nutritional requirements for the production of dithiolopyrrolone antibiotics by Saccharothrix algeriensis NRRL B-24137
The amino acid and humic acid requirements of Saccharothrix algeriensis NRRL B-24137 for growth and production of the dithiolopyrrolone antibiotics were studied in a semi-synthetic medium (SSM). Nature and concentration of amino acids and humic acid strongly influenced the
growth and dithiolopyrrolone specific production.
The highest value of thiolutin (acetyl-pyrrothine) specific production was obtained in the presence of 1 g/l humic acid (336 mg/g DCW), and in the presence of 5mM l-cystine (309 mg/g DCW) as compared to 19 mg/g DCW obtained with the control. Furthermore, thiolutin production
was increased about six-fold, four-fold and three-fold in the presence of l-proline, l-glutamic acid and dl-histidine, respectively. In contrast,the production of thiolutin was reduced by addition of other amino acids such as l-glutamine, dl-ethionine, l-methionine and l-arginine. The highest value of isobutyryl-pyrrothine production was obtained in the presence of 2,6-diaminopimelic acid and l-lysine (7.8 and 1.0 mg/g DCW,
respectively). However, the highest value of butanoyl-pyrrothine production was obtained in the presence of humic acid (6.6 mg/g DCW), followed by l-cysteine and l-proline (3.6 and 3.2 mg/g DCW, respectively). In addition, the maximum specific production of senecioyl-pyrrothine (29 mg/g
DCW) and tigloyl-pyrrothine (21 mg/g DCW) was obtained in the presence of humic acid. We found that, except for isobutyryl-pyrrothine, production of all dithiolopyrrolones was favoured by addition of l-proline. The maximum specific production was obtained with l-proline at
concentrations of 2.50mM for thiolutin (133mg/gDCW),1.25mMfor senecioyl-pyrrothine, tigloyl-pyrrothine and butanoyl-pyrrothine production (29, 23 and 3.9 mg/gDCW, respectively). Production of all dithiolopyrrolones strongly decreased as the l-methionine or dl-ethionine concentration was increased in the culture medium
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