A model-based approach to designing developmental toxicology experiments using sea urchin embryos

The key aim of this paper is to suggest a more quantitative approach to designing a dose–response experiment, and more specifically, a concentration–response experiment. The work proposes a departure from the traditional experimental design to determine a dose–response relationship in a developmental toxicology study. It is proposed that a model-based approach to determine a dose–response relationship can provide the most accurate statistical inference for the underlying parameters of interest, which may be estimating one or more model parameters or pre-specified functions of the model parameters, such as lethal dose, at maximal efficiency. When the design criterion or criteria can be determined at the onset, there are demonstrated efficiency gains using a more carefully selected model-based optimal design as opposed to an ad-hoc empirical design. As an illustration, a model-based approach was theoretically used to construct efficient designs for inference in a developmental toxicity study of sea urchin embryos exposed to trimethoprim. This study compares and contrasts the results obtained using model-based optimal designs versus an ad-hoc empirical design.

Beyond the Nature-Culture Frontier

In order to challenge the culture–nature dichotomy, this article investigates two festivities centered around fishing and consuming the sea urchin in two different locations: the Suape Bay Ouriçada (Brazil) in the Southern Hemisphere, and the Carry-le-Rouet Oursinade (France) in the Northern Hemisphere. This study employs both bibliographic and ethnographic research carried out at the two festivals over the last six years. The communities that originated these sea urchin festivals are both historically connected to artisanal fishing traditions that aim at creating bonds of sociability and connection with nature. While these festivities feature a wide variety of “things,” the one that stands out is the sea urchin itself. During these festivals, this species is taken by human hands from their habitat on the bottom of the Atlantic Ocean or the Mediterranean Sea to become the main reason for celebration and sociability in two different communities. On the one hand, sea urchin festivals can be seen as the heritage of local immaterial culture and as a symbol of the struggle for environmental protection. On the other hand, they are both the victim and the perpetrator of environmental degradations that threaten the event’s survival. Although the communities in these two geographic locations devised very different celebratory rituals around the same marine creature, by comparing and contrasting the two festivities we can contend that, despite their specificities, these sea urchin festivals challenge the culture–nature dichotomy. In other words, it is precisely through food that the natural and cultural worlds can become one.