Paris West University Nanterre La Défense

About: Paris West University Nanterre La Défense is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Finite element method. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

How do African grey parrots (Psittacus erithacus) perform on a delay of gratification task

Abstract: Humans and other animals often find it difficult to choose a delayed reward over an immediate one, even when the delay leads to increased pay-offs. Using a visible incremental reward procedure, we tested the ability of three grey parrots to maintain delay of gratification for an increasingly valuable food pay-off. Up to five sunflower seeds were placed within the parrot’s reach, one at a time, at a rate of one seed per second. When the parrot took a seed the trial was ended and the birds consumed the accumulated seeds. Parrots were first tested in daily sessions of ten trials and then with single daily trials. For multiple trial sessions, all three parrots showed some limited improvement across 30 sessions. For single trial sessions, only one parrot showed any increase in seed acquisition across trials. This parrot was also able to consistently obtain two or more seeds per trial (across both multiple and single trial conditions) but was unable to able to wait 5 s to obtain the maximum number of seeds. This parrot was also tested on a slower rate of seed presentation, and this significantly reduced her mean seed acquisition in both multiple and single trial conditions, suggesting that both value of reward available and delay duration impact upon self-control. Further manipulation of both the visibility and proximity of seeds during delay maintenance had little impact upon tolerance of delays for both parrots tested in this condition. This task demanded not just a choice of delayed reward but the maintenance of delayed gratification and was clearly difficult for the parrots to learn; additional training or alternative paradigms are required to better understand the capacity for self-control in this and other species.

A Historical Perspective on Science and Its “Others”

Abstract: Reflecting on the debate about the value of the category “popular science” to historians, this essay argues that the model of legitimate science that is currently emerging invites us to consider how the notions of science and the public have been mutually configured and reconfigured over time. It begins by pointing to the tremendous impact of technosciences on the public sphere. The recent shift from the deficit model to the participatory model has profoundly changed the values underlying science communication. Whereas previously such communication was performed in the name of science, it is now performed in the name of democracy. This political turn suggests that we should consider symmetrically not only how science and its public face are socially constructed but also how the notion of a lay public has been constructed by scientific practices. Finally, the essay suggests that historical studies should focus on the mechanisms of demarcation and discrimination between science and rival forms of k...

Experience Rating through Heterogeneous Models

Abstract: This paper presents statistical models which lead to experience rating in insurance. Serial correlation for risk variables can receive endogeneous or exogeneous explanations. The paper recalls that the main interpretation for automobile insurance is exogeneous, since positive contagion is always observed for the number of claims reported and since true contagion should be negative. This positive contagion can be explained by the revelation throughout time of a hidden features in the risk distributions. These features are represented by heterogeneity components in a heterogeneous model. Prediction on longitudinal data can be performed through the heterogeneous model, and the paper provides consistent estimators for models related to number and cost of claims. Examples are given for count data models with a constant or time-varying heterogeneity components, one or several equations, and for a cost-number model on events. Empirical results are presented, which are drawn from the analysis of a French data base of automobile insurance contracts.

Financial Markets and the Transition to a Low-Carbon Economy: Challenging the Dominant Logics:

Abstract: Financial markets play a major role in contributing to the transition to a low-carbon economy. Although many initiatives and developments are taking place, this is just the beginning. In this artic...