Taste-Masking: Function of Exaggerated Prandial Drinking in Desalivate Mice

Taste thresholds for the bitter compound sucrose octaacetate (SOA) were elevated by desalivation in mice. Thresholds were determined for control and experimental animals both before and after ligation of all salivary ducts. There was a significant increase in SOA thresholds in the desalivate mice, and the pre- to post-operative differences in threshold between the control and experimental groups were significant. The altered response to SOA by desalivate mice is shown to be due to the assumption of a prandial pattern of drinking as a result of desalivation. This conclusion is based on experiments with wet mash which failed to show any differences in threshold between the same control and desalivate mice that demonstrated a significant difference when tested on fluids and dry pellets

Role of Olfaction in Taste-Aversion to PTC in Mice

The objective of most taste research involving choice is to eliminate from the experiment all cues to the animal except those that are strictly gustatory. Among those potentially confounding cues, one of the most obvious is olfaction, although it often remains uncontrolled in taste experiments. The present report clearly demonstrates the role played by olfaction in a discrimination experiment with C57B1/6 and CFW mice as regards their response to phenylthiocarbamide (PTC) when paired with water. The results have implications for conclusions drawn by other investigators who have attributed differences in PTC sensitivity in mice to taste alone

Congruences in ordered pairs of partitions

Dyson defined the rank of a partition (as the first part minus the number of parts) whilst investigating certain congruences in the sequence p−1(n). The rank has been widely studied as have been other statistics, such as the crank. In this paper a “birank” is defined which relates to ordered pairs of partitions, and is used in an elementary proof of a congruence in p−2(n

Non-linear Redshift-Space Power Spectra

Distances in cosmology are usually inferred from observed redshifts - an estimate that is dependent on the local peculiar motion - giving a distorted view of the three dimensional structure and affecting basic observables such as the correlation function and power spectrum. We calculate the full non-linear redshift-space power spectrum for Gaussian fields, giving results for both the standard flat sky approximation and the directly-observable angular correlation function and angular power spectrum. Coupling between large and small scale modes boosts the power on small scales when the perturbations are small. On larger scales power is slightly suppressed by the velocities perturbations on smaller scales. The analysis is general, but we comment specifically on the implications for future high-redshift observations, and show that the non-linear spectrum has significantly more complicated angular structure than in linear theory. We comment on the implications for using the angular structure to separate cosmological and astrophysical components of 21 cm observations.Comment: 22 pages, 6 figures, changed to version accepted in Physics Review

Cartel and Oligopoly Pricing of Nonreplenishable Natural Resources

This essay is concerned with the implications of these structures in markets for nonrenewable natural resources. Following Hotelling (1931) and numerous subsequent authors, we assume that the total reserves of the resource in the hands of each producer cannot be increased and are reduced by production. Demand and cost conditions, including the relevant rate of interest, are constant over time. In such a world, producers must rationally consider price or output paths over time, so that both models outlined above become non-zero sum differential games. In what follows, we examine solutions to the games implied by various assumptions

Configuration Controllability of Simple Mechanical Control Systems

In this paper we present a definition of "configuration controllability" for mechanical systems whose Lagrangian is kinetic energy with respect to a Riemannian metric minus potential energy. A computable test for this new version of controllability is derived. This condition involves an object which we call the symmetric product. Of particular interest is a definition of "equilibrium controllability" for which we are able to derive computable sufficient conditions. Examples illustrate the theory

Configuration Controllability of Simple Mechanical Control Systems

In this paper we present a definition of 'configuration controllability' for mechanical systems whose Lagrangian is kinetic energy with respect to a Riemannian metric minus potential energy. A computable test for this new version of controllability is derived. This condition involves an object that we call the symmetric product. Of particular interest is a definition of 'equilibrium controllability' for which we are able to derive computable sufficient conditions. Examples illustrate the theory

Problem equivalence and necessary conditions of relaxed dynamic programming type in optical control

Imperial Users onl