Epidemiologic network inference

Statistics and Computing - In many epidemiologic models, a disease is assumed to spread along a contact network. We aim to infer this network, in addition to the epidemiologic model parameters,...     

Child welfare workers' practice in cases involving domestic violence

This paper reports the findings of an exploratory and qualitative study of child welfare workers' practice in cases involving domestic violence. The research aimed to focus on child welfare workers' interventions with families experiencing domestic violence, elements influencing the child welfare workers' decisions, and the factors facilitating and creating obstacles for intervention. An analysis of the qualitative data showed that child welfare workers have different ways of intervening in cases involving domestic violence. Also, the interventions were especially centred on women victims of violence and they were held responsible for protecting their children. Finally, the dilemmas and difficulties which child welfare workers face in these cases are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Mental Imagery and Production of Hand Gestures While Speaking in Younger and Older Adults

Speech and conversational hand gestures were recorded during interviews of 23 younger (M = 21 years) and 19 older adults (M = 70 years). Three kinds of questions were used in order to activate either visual images, motor images, or no mental image (abstract topics). On average, the rate of gesture production did not differ in younger and older adults, but it was significantly influenced by imagery conditions. Gesture production was higher in the motor than in the visual imagery condition, and lowest in the abstract condition. A significant interaction between age and imagery conditions influenced the proportion of representational gestures, which were relatively less frequent in older adults, especially in the visual imagery condition. Content analysis of verbal responses showed that imagery values did not differ in younger and older adults, but that concrete words were less frequent in responses to abstract questions than in the two other conditions. The implications of these results concerning the mechanisms of gesture production and the age-related changes in conversational behavior are discussed.     

Wage Bargaining with On‐the‐Job Search: Theory and Evidence

Most applications of Nash bargaining over wages ignore between‐employer competition for labor services and attribute all of the workers' rent to their bargaining power. In this paper, we write and estimate an equilibrium model with strategic wage bargaining and on‐the‐job search and use it to take another look at the determinants of wages in France. There are three essential determinants of wages in our model: productivity, competition between employers resulting from on‐the‐job search, and the workers' bargaining power. We find that between‐firm competition matters a lot in the determination of wages, because it is quantitatively more important than wage bargaining à la Nash in raising wages above the workers' “reservation wages,” defined as out‐of‐work income. In particular, we detect no significant bargaining power for intermediate‐ and low‐skilled workers, and a modestly positive bargaining power for high‐skilled workers.     

Nonstationarity and Level Shifts With an Application to Purchasing Power Parity

This study considers testing for a unit root in a time series characterized by a structural change in its mean. The analysis is in the spirit of Perron (1990a), who showed that the existence of such a shift in a stationary time series biases the usual tests for a unit root toward nonrejection. The approach is, however, different given that we suppose the date of the change to be unknown. The statistic of interest is then the minimal t statistic over all possible breakpoints in regressions similar to those proposed by Perron (1990a). Other related statistics are also discussed. We derive and tabulate the asymptotic distributions of interest. Most of the emphasis, however, is given to the tabulation of finite-sample critical values using simulation experiments. Particular attention is given to the effect, on the finite-sample critical values, of various procedures to select the appropriate order of the estimated autoregressions. We apply the tests to analyze the issue of purchasing power parity between the United States and the United Kingdom and also between the United States and Finland, whose real exchange rates are characterized by apparent shifts in level when using particular price indexes.     

Constraint-based model for the cyclic multi-hoists scheduling problem

This article presents a method for the resolution of a material handling scheduling problem. The case studied is a real industrial problem. It consists of finding a cyclic schedule for hoist movements in a treatment surface shop. In this kind of facility, several hoists are used for all the handling operations and they have to share common zones. Then it is necessary to control that there is no collision. The mathematical formulation of the problem is based on a combination of disjunctive constraints. The constraints describe either movement schedule or collision avoidance. The resolution procedure presented identifies all the collision configurations and then uses a branch and bound-like algorithm to find the optimal solution of a given problem. The language chosen for our implementation is the constraint logic programming language: Prolog IV, which is able to solve constraints with rational variables. It actively uses the constraint propagation mechanism that can be found in several languages.     

Science news in the European dailies,the invisible network of the agenda setting

A survey of the development of press coverage of scientific and technical information in the main European dailies¹, reveals three major trends—a general explosion of coverage in the Community countries studied, an increasingly specialized body of science writers and, finally, a lack of control of the networks that communicate scientific information and ensure its recognition at an international level. Even though the subject matter is mainly international, science reporting in the daily press is still in fact a question of “jobbing”; and expresses all the cultural diversity of Europe.     

Evaluation of a Sexual Abuse Prevention Workshop in a Multicultural,Impoverished Urban Area

Participants in the ESPACE sexual abuse prevention workshop were in grades 1 through 4 and attended three Montreal, Canada, public schools in low socioeconomic areas. The sample was culturally diverse, with half born outside of Canada. An evaluation was conducted to explore the effects associated with participating in the workshop and the effects of booster sessions conducted two years later. Outcomes included knowledge gained, the ability to offer behavioral responses to abusive situations, peer victimization, sense of safety, empathy, self-efficacy, and support. Results revealed that participants in this sample obtained low scores on measures of sexual abuse knowledge and that short booster sessions that elicit children's recall of the learned material might produce greater improvements.     

Interweaving Objects,Gestures, and Talk in Context

In a large French hospital, a group of professional experts (including physicians and software engineers) are working on the computerization of a blood-transfusion traceability device. By focusing on a particular moment in this slow process of design, we analyze their collaborative practices during a work session. The analysis takes a praxeological and interactionist approach and is inspired by discussions on the role of artifacts in social practices currently developed within various research frameworks in this field: activity theory, distributed cognition, conversation analysis, and actor network theory. After a brief presentation of the place of objects and artifacts in these ways of approaching action and human cognition, we show how the collective activity analyzed here is generated by the interweaving of discursive, gestural, and artifactual resources.