Impact of a Cost Minimisation User Cost Model on Public Transport Subsidy

We show that optimal public transport subsidy is sensitive to the use of alternative user cost models, and that a model based on cost minimisation principles may lead to an improvement in subsidy estimates. For the case of homogeneous consumers and non-peaked demand, the cost minimisation user cost model yields optimal subsidy estimates which differ by up to 55% from those generated by existing'models. Multiple optimal subsidy equilibria may also exist arising from a kink in the user cost schedule at a critical frequency and a resulting discontinuity in the marginal benefit of frequency enhancement scheduleefficiency; economic models; costs; economic equilibrium

Mycoplasma Contamination Revisited: Mesenchymal Stromal Cells Harboring Mycoplasma hyorhinis Potently Inhibit Lymphocyte Proliferation In Vitro

Mesenchymal stromal cells (MSC) have important immunomodulatory effects that can be exploited in the clinical setting, e.g. in patients suffering from graft-versus-host disease after allogeneic stem cell transplantation. In an experimental animal model, cultures of rat T lymphocytes were stimulated in vitro either with the mitogen Concanavalin A or with irradiated allogeneic cells in mixed lymphocyte reactions, the latter to simulate allo-immunogenic activation of transplanted T cells in vivo. This study investigated the inhibitory effects of rat bone marrow-derived MSC subsequently found to be infected with a common mycoplasma species (Mycoplasma hyorhinis) on T cell activation in vitro and experimental graft-versus-host disease in vivo.We found that M. hyorhinis infection increased the anti-proliferative effect of MSC dramatically, as measured by both radiometric and fluorimetric methods. Inhibition could not be explained solely by the well-known ability of mycoplasmas to degrade tritiated thymidine, but likely was the result of rapid dissemination of M. hyorhinis in the lymphocyte culture.This study demonstrates the potent inhibitory effect exerted by M. hyorhinis in standard lymphocyte proliferation assays in vitro. MSC are efficient vectors of mycoplasma infection, emphasizing the importance of monitoring cell cultures for contamination

Pollution standards vs charges under uncertainty

Conventional analysis of pollution control policy under uncertainty does not properly account for the potential cost effectiveness difference between standards and charges, thus drawing misleading conclusions for the case of inefficient standards. Correcting for this anomaly, the following conclusions can be drawn. When uncertainty involves the position of the marginal damage cost schedule, rather than policy indifference, a charge is always superior to an inefficient standard. When uncertainty is about the position of the marginal control cost schedule, policy indifference may occur, but if it does it must be the case that the slope of marginal damage cost exceeds that of marginal control cost. Copyright Kluwer Academic Publishers 1994

Service unreliability and bus subsidy

This paper addresses the link between the degree of unreliability of bus services and the level of optimal bus subsidy. With unreliability influencing user cost, and user cost being a key determinant of optimal bus subsidy, it follows that there is a link between service unreliability and optimal subsidy. Service unreliability is shown to have quite a significant influence on optimal subsidy. The impact is rather small in cases where a single type of user behaviour (random or planned) occurs. In contrast, the impact is much more significant when a logit model is used to predict choice between the two types of user behaviour.

User economies of scale and optimal bus subsidy / Peter Tisato.

Includes bibliographical references.iv. : ill. ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dept. of Economics, 199