4,354 research outputs found
BARLEY PRODUCTION COSTS: A CROSS-BORDER COMPARISON
Barley production costs are compared for five states and three Canadian provinces. A stochastic simulation, incorporating yield and exchange-rate risk, is used to characterize regional cost advantages in terms of probabilities.barley, production costs, yield risk, simulation analysis, Agricultural Finance, Production Economics,
COOPERATIVE MARKETING IN SPECIALTY GRAINS AND IDENTITY PRESERVED GRAIN MARKETS
Marketing of specialty and identity preserved grains has become an important strategy in the grain marketing industry and is being driven, in part, by consumer and processor demand and an interest in non-GM products. This study provides background and practices of numerous organizations involved in marketing of specialty/identity preserved grains. Supporting marketing activities are reviewed. Key factors in the success (or failure) of their efforts are identified. Major challenges facing the participants in the specialty/IP grain marketing industry are discussed. The primary focus is on the role of agricultural cooperatives and producer owned alliances.identity preservation, IP, segregation, traceability, specialty products, genetically modified, GM, non-GM, cooperative, alliance., Agribusiness,
ISSUES IN DEVELOPMENT AND ADOPTION OF GENETICALLY MODIFIED (GM) WHEATS
Development of genetically modified (GM) wheat varieties is proceeding; however, several critical issues remain the focus of contention. This project summarizes the current state of knowledge on some of these critical issues for commercialization of GM wheats. Background on the evolution of GM Wheats is presented. Then, agronomic adoption and competitiveness of GM crops; research on GM traits in wheat; consumer acceptance of GM crops (a separate section is included on issues related to consumer acceptance of GM crops); regulatory issues and status; international trade; testing, segregation, and identity preservation; and production and marketing risks are examined. Finally, there is a description of the likely marketing system to evolve and a discussion of outstanding issues.wheat, genetic modification, transgenic, marketing, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,
SOIL QUALITY ATTRIBUTE TIME PATHS: OPTIMAL LEVELS AND VALUES
We develop a dynamic soil quality model to evaluate optimal cropping systems in the northern Great Plains. Modeling soil quality attributes is feasible, and attribute model results apply to a wide range of soils. A crop production system with continuous spring wheat and direct planting is the most profitable system. This system has low soil erosion and high quality attributes, indicating the benefits of increased soil quality exceed the higher maintenance costs. On-site value of additional soil organic carbon (OC) ranges from 4/ton OC/hectare/year. These values for soil OC impact the optimum tillage practice, but not the crop rotation.Crop Production/Industries,
Stability of the replica-symmetric saddle-point in general mean-field spin-glass models
Within the replica approach to mean-field spin-glasses the transition from
ergodic high-temperature behaviour to the glassy low-temperature phase is
marked by the instability of the replica-symmetric saddle-point. For general
spin-glass models with non-Gaussian field distributions the corresponding
Hessian is a matrix with the number of replicas tending to
zero eventually. We block-diagonalize this Hessian matrix using representation
theory of the permutation group and identify the blocks related to the
spin-glass susceptibility. Performing the limit within these blocks we
derive expressions for the de~Almeida-Thouless line of general spin-glass
models. Specifying these expressions to the cases of the
Sherrington-Kirkpatrick, Viana-Bray, and the L\'evy spin glass respectively we
obtain results in agreement with previous findings using the cavity approach
The phase diagram of L\'evy spin glasses
We study the L\'evy spin-glass model with the replica and the cavity method.
In this model each spin interacts through a finite number of strong bonds and
an infinite number of weak bonds. This hybrid behaviour of L\'evy spin glasses
becomes transparent in our solution: the local field contains a part
propagating along a backbone of strong bonds and a Gaussian noise term due to
weak bonds. Our method allows to determine the complete replica symmetric phase
diagram, the replica symmetry breaking line and the entropy. The results are
compared with simulations and previous calculations using a Gaussian ansatz for
the distribution of fields.Comment: 20 pages, 7 figure
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Absolute cross section for Si2+(3s21S→3s3p1P) electron-impact excitation
We have measured the absolute cross section for electron-impact excitation (EIE) of Si2+(3s21S→3s3p1P) from energies below threshold to 11 eV above. A beams modulation technique with inclined electron and ion beams was used. Radiation at 120.7 nm from the excited ions was detected using an absolutely calibrated optical system. The fractional population of the Si2+(3s3p3Po) metastable state in the incident ion beam was determined to be 0.210±0.018 (1.65σ). The data have been corrected for contributions to the signal from radiative decay following excitation from the metastable state to 3s3p1P and 3p23P, and excitation from the ground state to levels above the 3s3p1P level. The experimental 0.56±0.08-eV energy spread allowed us to resolve complex resonance structure throughout the studied energy range. At the reported ±14% total experimental uncertainty level (1.65σ), the measured structure and absolute scale of the cross section are in good agreement with 12-state close-coupling R-matrix calculations
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