Presto: a software package for the simulation of diffusion processes

Conclusion Presto is a software which automatically generates FORTRAN code corresponding to approximation procedures of the solutions of stochastic differential systems.At the present time, it answers only to a few needs, but a diversification of its users and its simple internal structure could easily permit it to be developed towards a more ambitious system.Finally, let us mention that Presto is an INRIA product, which is free for academic institutions, universities, etc, which already have MAPLE and X-Windows licences. Presto can be run on any UNIX station under X-Windows environment.     

Partings and impartings: Toward a nonmedical approach to interruptions and terminations

It is the thesis of this paper that therapy offers a sequence of opportunities for the patient to experience a comfortable oscillation between togetherness and parting: thepetit partings within each hour, those moments of silence or withdrawal, partings at the end of hours, vacations, spontaneous interruptions (when allowed), and, ultimately, termination. A nonauthoritarian method particularly respecting and fostering the patient's self-determination is proposed.     

The identity transformation of biological parents in lesbian/gay stepfamilies

This paper investigates the identity transformation of lesbian and gay biological parents in homosexual stepfamilies. I explore previous models typically used to describe gay and lesbian identity formation, arguing that these models provide little understanding of the experiences of those who have been previously married and have children. Lesbians and gays who leave heterosexual unions and form homosexual stepfamily units undergo a series of transformations. The results show that the transition is relatively positive and less internally stigmatizing and stressful than that experienced by younger, childless lesbians and gays.     

A limit theorem on the dual core of a distributive social system

I consider abstract social systems where the distribution of wealth is an object of common concern. I study, in particular, the systems where liberal distributive social contracts consist of the Pareto-efficient distributions that are unanimously preferred to the initial distribution. I define a Dual Distributive Core from a process of decentralized auction on the budget shares of Lindahl associated with net transfers, operated by coalitions aiming at increasing the value of the public good for their members while maintaining their utility levels. I establish that the dual distributive core converges, as the number of distributive agents becomes large relative to the number of agent types, to a typically finite number of distributive liberal social contracts, which correspond to the Lindahl equilibria that are unanimously preferred to the initial distribution. This process of decentralized auction provides a theoretical foundation for contractual policies of redistribution. The comparison with the usual notion of core with public goods (Foley 1970) yields the following results in this context: the Foley-core is a subset, generally proper, of the set of liberal distributive social contracts; it does not contain, in general, distributive Lindahl equilibria.     

The role of teacher relationships in the lives of students

This chapter examines positive teacher-student relationships, as seen through a variety of psychological models and provides recommendations for schools and teachers.     

The critical ingredient: caring youth-staff relationships in after-school settings

After-school settings are interpersonal in nature, and the quality of the relationships that are forged can directly influence youths' attendance decisions and the developmental benefits they derive. Programs should more effectively capitalize on this potential for caring adult-staff relationships.     

Strategic management of public and non-market corporations

The author has developed a strategic framework for the management of ‘non-market corporations’ which he thinks better meets their peculiarities and specific needs by framing them in a relatively tight and rigorous socio-economic system relating to their internal logic. He believes that the proposed approach should provide the basis for a more constructive relationship between such corporations and the community at large and for better levels of performance     

Health Risk Assessment After Decontamination of the Beaches Polluted by the Wrecked ERIKA Tanker

Following the wreck of the oil tanker ERIKA off the north-west coast of France in December 1999, cleaning up of the beaches involved considerable work, which in any case could not be perfect. This raised the question of the short- and long-term health risks for the future bathers related to the toxicity of the remaining oil polycyclic aromatic hydrocarbons (PAHs). This risk assessment study was conducted to help health authorities plan risk management policies and inform the public. Thirty-six beaches were selected, representing a sample of the most frequently encountered topographic and beach usage situations; seven "control" beaches, unspoiled by ERIKA, were also investigated. Samples of water and sand were taken from each site, as well as from the surface of rocks. The 16 PAHs selected by the U.S. EPA were quantified in each environment. Several scenarios of exposure were contemplated: (1) a child between 2 and 4 years accidentally ingesting a small ball of fuel, (2) a child daily exposed throughout his holiday-time stay, (3) an adult (including a pregnant woman) spending his/her holidays on the coast, (4) an adult working on the beach, (5) and an adult practicing water sports. Among the available and significant toxicological values, the most conservative ones were selected for computing risks. The sand and water, after decontamination, were slightly polluted (respectively, 7.8 microg/kg and 23.3 ng/l of total 16 PAHs), with values similar to those found in the control beaches. By contrast, the rocky areas in some places were still highly polluted (up to 23 mg/kg on the surface layer). No lethal risk was found for a young child who had accidentally ingested a small ball of fuel. The life-long excess risks for skin cancer and for all other cancers were about 10-5 in scenarios including contact with the polluted rocks. In all other cases, excess risks were considerably lower. The hazard quotient for teratogenic effects was very small, except in scenarios where pregnant women would walk among rocks containing high pollution levels. In conclusion, exposure was mainly associated with polluted water among children, and with spoiled rocks for adults. Despite uncertainties, mainly dealing with the prediction of long-term risks following a short-term exposure, this study showed that beaches where pollution was no longer visible after decontamination did not entail any significant health risks and could be opened to the public.