To determine whether Staphylococcus aureus strains isolated from chickens were potential causes of human intoxications, 586 strains from diseased and healthy chickens obtained from 52 farms in several districts of Japan were examined. Of these, 16 strains produced staphylococcal enterotoxins. One-half of the enterotoxigenic strains were isolated from diseased chickens exclusively suffering from vesicular dermatitis, and another half were from healthy chickens. The enterotoxin types D and C were dominant in the strains from diseased and healthy chickens, respectively. The enterotoxigenic strains differed from the nonenterotoxigenic strains in several of their biochemical properties, and in their susceptibility to International human phages, and insusceptibility to Shimizu's avian phages group I which lyse most of the staphylococci of chicken origin. These differences may suggest that the enterotoxigenic strains of chicken origin were proper to humans but not to chickens.

This paper presents some substantial relationships between the revealed preference test for a data set and the shortest path problem of a weighted graph. We give a unified perspective of several forms of rationalizability tests based on the shortest path problem and an additional graph theoretic structure, which we call the shortest path problem with weight adjustment. Furthermore, the proposed structure is used to extend the result of Quah (2014), which sharpened the classical Afriat's Theorem-type result.

In this paper, we introduce production into the standard general equilibrium model with asymmetric information, which was proposed by Dubey et al. (Cowles Foundation Discussion Paper 2000; Econometrica 2005). In such an economy, there is no rational explanation for producers’ delivery upper bounds while the endowments naturally limit consumers’ deliveries. However, we show that the typical equilibrium allocation of the asymmetric information economy necessarily and substantially depends on such exogenous upper bounds (Example 1 and Theorem 1). In other words, an equilibrium existence theorem without such upper bounds, even if such exists, will typically fail to treat the asymmetric information problem, e.g., the adverse selection problem. Hence, to treat the equilibrium existence problem under the informational asymmetry appropriately, we have to extend the standard model so that the delivery upper bounds need not to be specified explicitly. For this purpose, we propose a quite natural and realistic assumption with respect to the technological condition related to the market delivery, i.e., the existence of some small standardization, commoditization, and/or transaction costs of market deliveries is shown to be sufficient (Theorem 3).