Summary report on a review of biological mechanisms for application to instrument design, Volume III

Biological mechanisms for application of instrument design - mechanoreception, chemoreception, thermoreception, photoreception, and electro-receptors and magnetic field sensor

Optimal Institutional Mechanisms for Funding Generic Advertising: An Experimental Analysis

Given the uncertain legal status of generic advertising programs for agricultural commodities, alternative voluntary funding institutions are investigated hat could provide a high level of benefits to producers. This experimental study simulates key economic and psychological factors that affect producer contributions to generic advertising. The results suggests that producer referendum play a critical role in increasing contributions and that producer surplus is maximized by a Provision Point Mechanism instituted by producer referendum with thresholds ranging from 68% to 90%, and expected funding from 47% to 77% of the time, depending on the level of advertising effectiveness.Marketing,

Do rBST-Free and Organic Milk Stigmatize Conventionally Produced Milk?

Producers are continually seeking to differentiate their products in the marketplace. A common approach is via labeling where differences in production methods are marketed. Yet, positive labeling for the new product has the potential to stigmatize the conventionally produced product by highlighting perceived problems with the product. The net economic result can be negative to producers as the conventional product that dominates the market is stigmatized by the new product that has little market share, and this leads to consumers decreasing their willingness to pay for the conventional product. This experimental research identifies this stigma effect in the case of milk, where the presentation of rBST-Free milk reduces consumers' willingness to purchase conventional milk.Demand and Price Analysis,

Status-Quo-Bias and Voluntary Contributions: Can Lab Experiments Parallel Real World Outcomes for Generic Advertising?

Many commodities have programs assessing producers for generic advertising. Ads such as "Got Milk?" and the "Incredible Edible Egg" are a public good for producers. Most of these programs originally used the Voluntary Contribution Mechanism, but have now become mandatory because of free-riding. This research simulates both the economic and psychological details of the egg industry in experiments that produce strikingly realistic results. Because mandatory programs have recently been declared unconstitutional, we also the test the Provision Point Mechanism and show that observed low levels of free-riding for both mechanisms are the result of status quo bias.Marketing, H40, H41, M37,

Voluntary Funding for Generic Advertising Using a Provision Point Mechanism: An Experimental Analysis of Option Assurance

The mandatory nature of generic advertising funding remains a contentious issue. Theoretically and in laboratory environments, a provision point mechanism with a money-back guarantee offers an attractive voluntary alternative to the standard voluntary contribution mechanisms, yet in practice, few examples of multiple-round provision point mechanisms exist. A practical concern with applying these mechanisms is that even a slight shortfall in contributions relative to the designated funding threshold in one period would engender an irreversible shutdown of administrative capacity with negative consequences for subsequent periods. This paper uses experimental economics to test new two-threshold provision point mechanisms in the context of check-off programs for funding commodity marketing programs that would separately fund the minimum administrative capacity and the more costly full marketing program. In these mechanisms, even if a funding shortfall occurs for the full marketing program, the low threshold can maintain the administrative capacity and retain the option for future funding of advertising. We demonstrate that providing such "option assurance" does not lead to a decrease in overall contributions and, in some settings, can increase producer surplus.Marketing,

On the Evolution of Thermonuclear Flames on Large Scales

The thermonuclear explosion of a massive white dwarf in a Type Ia supernova explosion is characterized by vastly disparate spatial and temporal scales. The extreme dynamic range inherent to the problem prevents the use of direct numerical simulation and forces modelers to resort to subgrid models to describe physical processes taking place on unresolved scales. We consider the evolution of a model thermonuclear flame in a constant gravitational field on a periodic domain. The gravitational acceleration is aligned with the overall direction of the flame propagation, making the flame surface subject to the Rayleigh-Taylor instability. The flame evolution is followed through an extended initial transient phase well into the steady-state regime. The properties of the evolution of flame surface are examined. We confirm the form of the governing equation of the evolution suggested by Khokhlov (1995). The mechanism of vorticity production and the interaction between vortices and the flame surface are discussed. The results of our investigation provide the bases for revising and extending previous subgrid-scale model.Comment: 15 pages, 22 postscript figures. Accepted for publication by the Astrophysical Journal. High resolution figures can be found at http://flash.uchicago.edu/~zhang/research_paper.htm

Creating topological interfaces and detecting chiral edge modes in a 2D optical lattice

We propose and analyze a general scheme to create chiral topological edge modes within the bulk of two-dimensional engineered quantum systems. Our method is based on the implementation of topological interfaces, designed within the bulk of the system, where topologically-protected edge modes localize and freely propagate in a unidirectional manner. This scheme is illustrated through an optical-lattice realization of the Haldane model for cold atoms, where an additional spatially-varying lattice potential induces distinct topological phases in separated regions of space. We present two realistic experimental configurations, which lead to linear and radial-symmetric topological interfaces, which both allows one to significantly reduce the effects of external confinement on topological edge properties. Furthermore, the versatility of our method opens the possibility of tuning the position, the localization length and the chirality of the edge modes, through simple adjustments of the lattice potentials. In order to demonstrate the unique detectability offered by engineered interfaces, we numerically investigate the time-evolution of wave packets, indicating how topological transport unambiguously manifests itself within the lattice. Finally, we analyze the effects of disorder on the dynamics of chiral and non-chiral states present in the system. Interestingly, engineered disorder is shown to provide a powerful tool for the detection of topological edge modes in cold-atom setups.Comment: 18 pages, 21 figure

Identifying Significant Characteristics of Organic Milk Consumers: A CART Analysis of an Artefactual Field Experiment

The organic dairy category is one the fastest growing categories of organic production in the U.S. Organic milk consumers generally cite perceived health benefits and lower risk of food contamination, as well as perceived superior quality and low environmental impact of organic farming methods, as the major motivations for preference of organic over conventional milk. While the properties of organic milk that are valued by consumers are fairly well-known, there is more ambiguity regarding the demographic characteristics of the typical organic milk consumer. This research makes use of experimental data and utilizes a relatively novel non-parametric modeling approach, the CART analysis, in identifying how willingness to pay for organic milk varies with the demographic profile of experiment participants. A more traditional econometric approach utilizing a Tobit regression is also performed to compare the results of the two models. The study finds that perceived taste of organic milk and concern for the risk of consuming conventional milk are major factors that separate experiment participants into groups with high and low WTP for organic milk.Consumer/Household Economics,