THE RESPONSIVENESS OF U.S. RICE ACREAGE TO PRICE AND PRODUCTION COSTS

Ordinary least squares and seemingly unrelated regression procedures were used to analyze the impacts of changes in rice prices and production costs on U.S. rice planted acreage. National and regional response models were estimated over the 1970-92 period. Supply-inducing prices of rice were estimated as a function of effective rice support prices and seasonal average market prices. Expected production costs per acre were estimated using lagged actual total variable cash production expenses per acre adjusted by the previous 3-year average annual change in variable expenses. Estimated short-run price and production cost elasticities were found to be inelastic at the national level. However, the magnitude of the production cost elasticities were found to be greater than the price elasticities. Estimated long-run elasticities at the U.S. level were inelastic for changes in price but elastic for changes in production costs. Although acreage response varied across regions, similar relationships were found between price and production cost elasticities.Rice, Acreage response function, Price elasticity, Crop Production/Industries,

PROJECTED COSTS AND RETURNS - SUGARCANE, LOUISIANA, 2001.

This report presents estimates of costs and returns associated with sugarcane production practices in Louisiana for 2001. It is part of a continuing effort to provide farmers, researchers, extension personnel, lending agencies and others working in agriculture and/or agribusiness timely planning information. Sugarcane production is unique in that it is a perennial crop grown in a rotation; processing, storage and marketing services are provided by a single entity and payments for said services are "in kind." Further, the large majority of growers are tenants, paying approximately 20 percent of the "after milling crop proceeds" (12.2% of gross production) for land. Returns shown in Table 1A-3C and in the whole farm analysis in Appendix A reflect returns to management and risk. No charges for family living expenses or management are included as a cost in this analysis.Farm Management,

A Sequential Rationality and Efficiency Test of U.S. Department of Agriculture Program Crop Price Estimates: Rice, Wheat, and Soybeans

This paper examines the USDA price estimates of rice, wheat, and soybeans and whether spot commodity prices reflect price information embodied in USDA estimates. Results indicate that the monthly USDA estimates are failed to meet a rationality condition. Rice and wheat actual prices marginally incorporate the information embodied in USDA past price estimates.Agricultural and Food Policy, Research Methods/ Statistical Methods, Crop Production/Industries,

Charge and hydrophobicity effects at nano-bio interfaces

Gold nanoparticles coated with bio-compatible ligands are promising tools for biomedical applications due their water solubility, bio-compatibility and efficient light-to-heat conversion. In in vivo applications, nanoparticles come in contact with many biological molecules before being delivered to cells. The understanding of the physical and chemical nature of these different nano-bio interfaces is crucial to the rational design of nanoparticles with biomedical applications. The aim of this thesis is to understand, by molecular dynamics, how the composition, hydrophobicity and charge of the ligand shell of a small gold nanoparticle can influence its interaction with i. the solvent, ii. model biological membranes and iii. serum proteins. For each of these relevant interfaces we address a specific case of study. In our first case study, we address the role of ligands during the transfer of heat from a hot irradiated gold nanoparticle to the surrounding solvent (water). Indeed, in photothermal therapies laser-irradiated resonant nanoparticles convert light into heat, which is then released to the surrounding biological tissues. Nevertheless, no clear physical interpretation is currently available to explain thermal transport at the nanoparticle surface, where a solid-liquid (metal--ligand) interface is coupled to a liquid-liquid (ligand--solvent) interface. We use computer simulations to show that thermal transport at the nanoparticle surface depends on solvent diffusivity at the ligand--solvent interface. Furthermore, using physical indicators of water confinement around hydrophobic and hydrophilic ligands, we develop a predictive model to allow engineering of nanoparticle coatings with the desired thermal conductivities at the nanoscale. The second case study is the interaction between an anionic, monolayer-protected gold nanoparticle and a model neutral lipid membrane. The cell membrane is the first barrier that gold nanoparticles meet in cell-targeted applications. Here we show how the nanoparticle surface functionalization, and in particular its charge state, can drive the mechanism of interaction with a zwitterionic lipid membrane. Our third case study is the interaction between a monolayer-protected gold nanoparticle and a serum protein, ubiquitin. Indeed, when nanoparticles circulate in the bloodstream, they come in contact with many serum proteins, which can irreversibly bind to nanoparticles, thus changing the surface they expose to the biological environment. We combine computer simulations and experimental results to study how the ligand charge and composition influence the interaction between nanoparticles and ubiquitin. We find that interfacial water molecules are more bound to the nanoparticles with the largest negative charge and this reflects in an increase of their hydrodynamic radius and in a slower kinetics of binding to the protein during unbiased simulations

PROJECTED COSTS AND RETURNS - SUGARCANE, LOUISIANA, 1997

This report presents estimates of costs and returns associated with sugarcane production practices in Louisiana for 1997. It is part of a continuing effort to provide farmers, researchers, extension personnel, lending agencies and others working in agriculture and/or agribusiness timely planning information.Farm Management,

PROJECTED COSTS AND RETURNS - RICE, LOUISIANA, 1997; PROJECTED COSTS AND RETURNS - SOYBEANS, CORN, MILO, WHEAT, AND WHEAT-SOYBEAN DOUBLE CROP, SOUTHWEST LOUISIANA, 1997

Farmers are annually faced with critical management decisions that impact the employment of production inputs for various crop enterprises and the combination of crops that will be assembled into a cropping system. The need for reliable information is crucial if sound production decisions are t o be made. Planning information plays a pivotal role in the development of 1997 production plans by farmers and is important in supporting their efforts to secure the necessary resources to carry out their plans. In addition, information regarding production alternatives and costs and returns for major crop enterprises is needed by extension personnel, researchers, lending institutions, and others involved in agriculture or agribusiness. This information has become all the more critical with the enactment of Federal Agricultural Improvement and Reform (FAIR) Act in 1996. The purpose of this report is to provide for tenant and owner operator situations the 1997 projected cost and return estimates for the following enterprises: rice in Southwest, Central, and Northeast Louisiana and soybean, corn, milo, wheat, and wheat-soybean double crop in Southwest Louisiana.Farm Management,

INCORPORATION OF WITHIN-SEASON YIELD GROWTH INTO A MATHEMATICAL PROGRAMMING SUGARCANE HARVEST SCHEDULING MODEL

This study focuses on the development of a optimal harvest scheduling mathematical programming model which incorporates within-season changes in perennial crop yields. Daily crop yield prediction models are estimated econometrically for major commercially grown sugarcane cultivars. This information is incorporated into a farm-level harvest scheduling linear programming model. The harvest scheduling model solves for an optimal daily harvest schedule which maximizes whole farm net returns above harvesting costs. Model results are compared for a commercial sugarcane farm in Louisiana.sugarcane, harvest scheduling, within-season yield growth, Crop Production/Industries,