A quadratic lower bound for colourful simplicial depth

We show that any point in the convex hull of each of (d+1) sets of (d+1) points in ℝ ^d is contained in at least ⌊(d+2)²/4⌋ simplices with one vertex from each set. Both authors were supported by NSERC Discovery grants. Additionally, T. Stephen was supported by DFG FG-468 and the Dynamical Systems research focus at the University of Magdeburg.     

The Role of Social Work Education in Advancing Social Development in the English-speaking Caribbean

This article presents a discussion of the role of professional social work education in advancing social development in the countries of the English-speaking Caribbean. It addresses issues around the development of the profession in the region, student enrolment, curriculum expansion and programme delivery by the institutions which offer social work education. The events which contributed to the emergence of social work education in the region during the fourth decade of the twentieth century and social work education's continued contribution to regional development are discussed. The prospective use of the new Global Agenda for Social Work and Social Development to advance the profession in the region in the twenty-first century is noted. The article concludes by highlighting the many challenges that currently impact social work education in the Caribbean and the fact that the development of social work education in the region is inextricably linked to the region's social development needs. Social work education as delivered through the University of the West Indies is used as the case in point for discussion.     

Combining pheromone-baited and food-baited traps for insect pest control: Effects of additional control by parasitoids

Summary Two age-structured population dynamic models are analyzed in which pheromone-baited trapping and food-baited trapping are used simultaneously to eradicate an insect pest. The pest species is assumed to be under partial control by a host-specific parasitoid species. The two models assume that density-dependent population regulation is accomplished either by host larval competition or by means of oviposition interference among the parasitoids. The two trap types interact in a positive synergistic manner and this combination appears to be very promising as a useful combination of pest control methods. Several features of the system are examined; the feature which appears to cause the greatest problem is the possibility of the parasitoids being attracted to the pheromone or the food traps. In either case, the degree of attraction does not have to be very great to undermine the control effort. It is seen that food trapping becomes indispensible if host pheromone is used by the parasitoids as a host-locating kairomone. If odor in the food traps is used by the parasitoids as kairomone, then the situation appears more optimistic, as the reduction in efficiency of the food traps appears much less than with the pheromone traps when pheromone acts as kairomone.     

Working relationships

This paper describes a workshop intended to promote greater understanding and future cooperation between health visitors, general practitioners and social workers. The workshop has been run for students on qualifying courses but its content and procedures are relevant for programmes for qualified workers. The paper outlines the aims and practice of the workshop and some of the issues arising from it.