An acreage response model for Arkansas rice farms

In recent years, market forces have signaled a strong demand for rice as well as other Arkansas crops. However, high fuel, fertilizer, and chemical costs have negatively impacted farm income, and these input costs are widely known to impact planting decisions of farmers. The goal of this study is to develop and estimate an acreage response model for rice. The model is used to compute acreage response elasticities and provides insight into roles that input costs and crop prices play in acreage decisions made by producers. Economic theory predicts that prices for important inputs such as fuels and fertilizers as well as the relative prices of rice and soybeans will impact acreage decisions. Soybean prices are expected to be important because most of the machinery needed to produce rice and soybeans is the same and these crops are already used commonly in rotation. Results of the study show that crop price variables do indeed play a significant role in producer planning. Short- and long-run own-price acreage response elasticities are estimated to be 0.69 and 1.19, respectively. Soybean prices have the expected negative impact on rice acreage with a cross-price elasticity of -0.33 in the short run and -0.57 in the long run. On the other hand, the expected economic impacts of input prices on rice acreage were not supported by the results. Estimated relationships were negative, as would be predicted by economic theory, but were not statistically significant

Particle Swarm Optimization Toolbox

The Particle Swarm Optimization Toolbox is a library of evolutionary optimization tools developed in the MATLAB environment. The algorithms contained in the library include a genetic algorithm (GA), a single-objective particle swarm optimizer (SOPSO), and a multi-objective particle swarm optimizer (MOPSO). Development focused on both the SOPSO and MOPSO. A GA was included mainly for comparison purposes, and the particle swarm optimizers appeared to perform better for a wide variety of optimization problems. All algorithms are capable of performing unconstrained and constrained optimization. The particle swarm optimizers are capable of performing single and multi-objective optimization. The SOPSO and MOPSO algorithms are based on swarming theory and bird-flocking patterns to search the trade space for the optimal solution or optimal trade in competing objectives. The MOPSO generates Pareto fronts for objectives that are in competition. A GA, based on Darwin evolutionary theory, is also included in the library. The GA consists of individuals that form a population in the design space. The population mates to form offspring at new locations in the design space. These offspring contain traits from both of the parents. The algorithm is based on this combination of traits from parents to hopefully provide an improved solution than either of the original parents. As the algorithm progresses, individuals that hold these optimal traits will emerge as the optimal solutions. Due to the generic design of all optimization algorithms, each algorithm interfaces with a user-supplied objective function. This function serves as a "black-box" to the optimizers in which the only purpose of this function is to evaluate solutions provided by the optimizers. Hence, the user-supplied function can be numerical simulations, analytical functions, etc., since the specific detail of this function is of no concern to the optimizer. These algorithms were originally developed to support entry trajectory and guidance design for the Mars Science Laboratory mission but may be applied to any optimization problem

Love is . . . an abstract word: the influence of phonological and semantic factors on verbal short-term memory in Williams syndrome

It has been claimed that verbal short-term memory in Williams syndrome is characterised by an over-use of phonological coding alongside a reduced contribution of lexical semantics. We critically examine this hypothesis and present results from a memory span task comparing performance on concrete and abstract words, together with a replication of a span task using phonologically similar and phonologically dissimilar words. Fourteen participants with Williams syndrome were individually matched to two groups of typically developing children. The first control group was matched on digit span and the second on vocabulary level. Significant effects were found for both the semantic and the phonological variables in the WS group as well as in the control groups, with no interaction between experimental variable and group in either experiment. The results demonstrate that, despite claims to the contrary, children and adults with WS are able to access and make use of lexical semantics in a verbal short-term memory task in a manner comparable to typically developing individuals

All That is Gold Does Not Glitter in Human Clinical Research: A Law-Policy Proposal to Brighten the Global Gold Standard for Drug Research and Development

This Article challenges the global science standard for putting new drugs on pharmacy shelves. The primary premise is that the gold standard of group experimental design is an antiquated extension of drug development\u27s crude-science past, and is inconsistent with the precision of contemporary genetics-the science that increasingly dominates the drug development pipeline. The Article identifies law-policy options that would raise the standard for human clinical research under the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use

All that is Gold Does Not Glitter in Human Clinical Research: A Law– Policy Proposal to Brighten the Global “Gold Standard” for Drug Research and Development

This Article challenges the global science standard for putting new drugs on pharmacy shelves. The primary premise is that the “gold standard” of group experimental design is an antiquated extension of drug development’s crude-science past, and is inconsistent with the precision of contemporary genetics— the science that increasingly dominates the drug development pipeline. The Article identifies law– policy options that would raise the standard for human clinical research under the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use

All That is Gold Does Not Glitter in Human Clinical Research: A Law-Policy Proposal to Brighten the Global Gold Standard for Drug Research and Development

This Article challenges the global science standard for putting new drugs on pharmacy shelves. The primary premise is that the gold standard of group experimental design is an antiquated extension of drug development\u27s crude-science past, and is inconsistent with the precision of contemporary genetics-the science that increasingly dominates the drug development pipeline. The Article identifies law-policy options that would raise the standard for human clinical research under the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use