A Nonparametric Bayesian Approach to Uncovering Rat Hippocampal Population Codes During Spatial Navigation

Rodent hippocampal population codes represent important spatial information about the environment during navigation. Several computational methods have been developed to uncover the neural representation of spatial topology embedded in rodent hippocampal ensemble spike activity. Here we extend our previous work and propose a nonparametric Bayesian approach to infer rat hippocampal population codes during spatial navigation. To tackle the model selection problem, we leverage a nonparametric Bayesian model. Specifically, to analyze rat hippocampal ensemble spiking activity, we apply a hierarchical Dirichlet process-hidden Markov model (HDP-HMM) using two Bayesian inference methods, one based on Markov chain Monte Carlo (MCMC) and the other based on variational Bayes (VB). We demonstrate the effectiveness of our Bayesian approaches on recordings from a freely-behaving rat navigating in an open field environment. We find that MCMC-based inference with Hamiltonian Monte Carlo (HMC) hyperparameter sampling is flexible and efficient, and outperforms VB and MCMC approaches with hyperparameters set by empirical Bayes

DID THE VOLUNTARY PRICE REPORTING SYSTEM FAIL TO PROVIDE PRICE TRANSPARENCY IN THE CASH MARKET FOR DRESSED STEERS: EVIDENCE FROM SOUTH DAKOTA

The information value of the former USDA voluntary price reporting system is investigated for dressed weight slaughter steers. The ability of the former system to promote market transparency and price discovery in the cash market is evaluated with state level mandatory price reporting data collected from September 1999 to April 2001. The empirical framework evaluates the informational value of public price reports according to the criteria established in the market integration literature. The empirical results indicate that in the cash market for dressed weight steers, in South Dakota and Nebraska the former voluntary price reporting system did foster market transparency and aided in the price discovery process.Livestock Production/Industries, Marketing,

The Voluntary Reporting System's Ability to Provide Price Transparency in the Cash Market for Dressed Steers: Evidence from South Dakota

The informational value of USDA's former voluntary price reporting system is investigated for dressed-weight slaughter steers sold by South Dakota producers. The ability of the former system to promote price transparency in the cash market is evaluated using state-level mandatory price reporting data collected from September 1999 to April 2001. The empirical framework examines the informational value of public price reports according to the criteria established in the market integration literature. The empirical results indicate that in the South Dakota cash market for dressed weight steers, the voluntary price reporting system fostered price transparency, and thus contributed to the price discovery process. Empirical evidence is also presented suggesting that strategic price reporting by market participants to influence the voluntary price reporting system was not detected during the period covered in this study.cointegration, competitive spatial equilibrium, error correction model, mandatory price reporting, marketing integration, price transparency, slaughter cattle spot market, voluntary price reporting, Demand and Price Analysis,

Local Government Behavior and Property Right Formation in Rural China

Secure land tenure is important to the development process, but China’s rural reforms have so far failed to provide farm households with this security. We examine the political economy of land tenure and find that local governments sacrifice tenure security in the interests of efficiency and equity. Local rent seeking also plays an important role, and is a likely source of the under-development of land rental markets. Our results further suggest that decreases in distortionary taxes and increases in the integrity of elections will lead to more secure tenure and an increased reliance on market land exchange.

Public Price Reporting in the Cash Market for Live Cattle: A Spatial Market Approach

Legislative authorization for the Livestock Mandatory Reporting Act of 1999 was renewed in October of 2006. One of the cited justifications for implementing mandatory reporting was that the voluntary reporting system for the slaughter cattle cash market was unable to provide accurate and timely market information. We extend the spatial market analysis literature by developing a methodology for detecting distortions in spatial relationships across related price series. Using spatially linked regional markets, we compare state-level mandatory price-reporting data to the U.S. Department of Agriculture voluntarily reported state data to determine if the spatial relationship between price-reporting mechanisms was disrupted by market distortions prior to implementation of federal mandatory price reporting. We found no empirical evidence of system failure; therefore, we conclude that market thinning or noncompetitive behavior had not reached the level necessary to disrupt the ability of the voluntary price-reporting system to provide timely and accurate price information.public price reporting, spatial markets, market integration, price transparency, price discovery, livestock markets, Livestock Production/Industries, Marketing,

Price Transparency in the Voluntary Price Reporting System for Live Cattle: Theory and Empirical Evidence

Interregional spatial linkages between South Dakota and Nebraska cash markets for slaughter cattle are investigated. Econometric procedures are used to test whether a thinning market effect or strategic price reporting behavior by packers has degraded market transparency under the voluntary price reporting system. Empirical evidence suggests transparency was not degraded.Demand and Price Analysis,

Modeling and Analysis of Multicommodity Network Flows via Goal Programming

In this research we focused on the mobility system modeled by the AMC mobility planner\u27s calculator (AMPCALC). We developed AMPCALC as a user-friendly tool and allow the user to easily carry out strategic airlift, air refueling and aeromedical evacuation calculations that are covered in Air Force Pamphlet 10-1403. In this study, Excel software and its macro language, Visual Basic for Application, are our two main tools. In the methodology of the thesis we examined fundamental aspects of the mobility system in AMPCALC. We discussed formulation logic of the mobility cycle. We presented ramp use optimization and tanker optimization processes. We also conducted verification and validation of AMPCALC. Sensitivity analysis of the model includes a response surface study. To be able to investigate the main effects and interaction effects of the input factors on closure time, we performed a 26 factorial design. No linear relations are observed, but some relations between inputs and closure time are observed

The Efficacy of the Grid Marketing Channel for Fed Cattle

Beef industry data suggest that carcass yield and quality grades have shown little improvement over the last six years. Trend analysis of grid market share and carcass quality suggests that grid pricing has not made sufficient progress in achieving the goals envisioned for it as a value based marketing system.grid pricing, price discovery, price reporting, slaughter cattle