THE ROLES OF MONEY IN AN ECONOMY AND THE OPTIMUM QUANTITY OF MONEY

What is the optimum quantity of money in a society? This paper answers this question both from the perspective of a utility maximizing model with real balances in the utility function, and employing an inventory theoretic model which focuses attention on the costs of transacting in different markets and on the storage costs of holding money. We find that socially optimal transactions patterns and inventory holdings can be induced by paying interest on money and bonds equal to the net rate of return on capital. This conclusion is however only valid if it is costless for the society to institute and operate such an interest payment mechanism. In a world where it is costly to institute and operate an interest payment mechanism, a social optimum requires that the rate of return on money and bonds must equal the net rate of return on capital minus the social cost of inducing individuals to hold optimal quantities of financial assets. It is therefore necessary to take account of both the potential gains in welfare from instituting interest payments on money and the real potential costs of such a policy. Reference: Economica, November, 1973 pp. 416-431

Effectiveness and Efficiency of Persuasive Space Graphics (PSG) in Motivating UK Primary School Children’s Hand Hygiene

Good hand hygiene is necessary to control and prevent infections, but many children do not adequately wash their hands. While there are classroom communications targeted at children, the toilet space, the location of many hand hygiene activities, is neglected. This paper describes an initial evaluation of “123” persuasive space graphics (images and messages integrated within an architectural environment that encourage specific actions). The effectiveness (whether hand hygiene improves) and efficiency (the ease with which a setting can adopt and implement an intervention) is evaluated in three UK schools and one museum. Five evaluations (participant demographic, handwashing frequency, handwashing quality, design persuasiveness, stakeholder views) were conducted. In the school settings, persuasive space graphics increased the quality and frequency of handwashing. In the museum setting, frequency of handwashing slightly increased. In all settings children found the graphics persuasive, and stakeholders also believed them to be effective. Stakeholders considered persuasive space graphics a low-cost and time-efficient way to communicate. It can be concluded that persuasive space graphics are effective in increasing hand hygiene, particularly in school settings where children have a longer exposure to the graphics. Persuasive space graphics are also an efficient low-cost means of communicating hand hygiene

Against the tide: the role of bacterial adhesion in host colonization

Evolving under the constant exposure to an abundance of diverse microbial life, the human body has developed many ways of defining the boundaries between self and non-self. Many physical and immunological barriers to microbial invasion exist, and yet bacteria have found a multitude of ways to overcome these, initiate interactions with and colonize the human host. Adhesion to host cells and tissues is a key feature allowing bacteria to persist in an environment under constant flux and to initiate transient or permanent symbioses with the host. This review discusses reasons why adhesion is such a seemingly indispensable requirement for bacteria–host interactions, and whether bacteria can bypass the need to adhere and still persist. It further outlines open questions about the role of adhesion in bacterial colonization and persistence within the host