Publications of 2025 in english

Endocrine disruptors alter mammary gland development, impair the ability to nourish offspring, and increase the cancer risk in animal models. Epidemiological studies reveal trends towards early mammary development, nursing problems, and breast cancer in younger women. Morphological changes in mouse postnatal mammary gland development are considered sensitive markers of endocrine disruption. While the mouse mammary gland is easily amenable to morphometric measurements from the fetal stage to full maturity, the rat mammary gland grows more conspicuously into the third dimension, hindering conventional morphometric analysis. However, since rats are more commonly used in international toxicological reproductive studies, it would be beneficial to include mammary gland whole-mount analysis in these studies. Using our quantitative software to perform computer-driven analysis of the rat mammary epithelium we examined the effects of gestational and postnatal exposure to ketoconazole, an antifungal medication that affects steroidogenesis, and to the estrogen diethylstilbestrol in the mammary glands of 6- and 22-day-old females. Both treatments produced effects at both ages; the epithelium was smaller and less complex in exposed animals compared to controls. Global analysis with the permutation test showed that morphological evaluation of the PND22 mammary gland is sensitive to endocrine disruption and possibly non-monotonic. In addition to revealing that ketoconazole altered the mammary gland structure, these results suggest that for future toxicology studies, day 22 (at weaning) is more suitable than day 6 because it showed significant measurements and trends. If the collection of mammary glands is added to existing international test methods, PND22 could be a relevant time point.

Keywords: Ketoconazole, Diethylstilbestrol, endocrine disruptors, perinatal exposure, mammary gland whole mount

Physics has several concepts of randomness that build on the idea that the possibilities are pre-given. By contrast, an increasing number of theoretical biologists attempt to introduce new possibilities, that is to say, changes of possibility space – an idea already discussed by Bergson and that was not genuinely pursued scientifically until recently (except, in a sense, in systematics, i.e, the method to classify living beings).
Then, randomness operates at the level of possibilities themselves and is the basis of the historicity of biological objects. We emphasize that this concept of randomness is not only relevant when aiming to predict the future. Instead, it shapes biological organizations and ecosystems. As an illustration, we argue that a critical issue of the Anthropocene is the disruption of the biological organizations that natural history has shaped, leading to a collapse of biological possibilities.

La physique possède plusieurs concepts de hasard qui reposent néanmoins tous sur l’idée que les possibilités sont données d’avance. En revanche, un nombre croissant de biologistes théoriciens cherchent à introduire la notion de nouvelles possibilités, c’est-à-dire des modifications de l’espace des possibles - une idée déjà discutée par Bergson et qui n’a pas été véritablement poursuivie scientifiquement jusqu’à récemment (sauf, en un sens, dans la systématique, c’est-à-dire la méthode de classification des êtres vivants).
Alors, le hasard opère au niveau des possibilités elles-mêmes et est à la base de l’historicité des objets biologiques. Nous soulignons que ce concept de hasard n’est pas seulement pertinent lorsqu’on cherche à prédire l’avenir. Au contraire, il façonne les organisations biologiques et les écosystèmes. À titre d’illustration, nous soutenons qu’une question cruciale de l’Anthropocène est la disruption des organisations biologiques que l’histoire naturelle a structurées, conduisant à un effondrement des possibilités biologiques.

Biologists are increasingly documenting anthropogenic disruptions, both at the organism and ecosystem levels, indicating that these disruptions are a fundamental, qualitative component of the Anthropocene. Nonetheless, the notion of disruption has yet to be theorized. Informally, disruptions are direct or indirect consequences of specific causes that impair the contribution of parts of living systems to their ability to last over time. To progress in this theorization, we work here on a particular case. Even relatively minor temperature changes can significantly impact plant-pollinator synchrony, disrupting mutualistic interaction networks. Understanding this phenomenon requires a specific rationale since models describing it use both historical and systemic reasoning. Specifically, history justifies that the ecosystem initially exists in a very narrow part of the possibility space where all its populations are viable, and the disruption leads to a more generic configuration where some populations are not viable. Building on this rationale, we develop a mathematical schema inspired by Boltzmann’s entropy, apply it to this situation, and provide a technical definition of disruption.

This is a transcribed and translated  a podcast of the interview concerning the 1st chapter of the book Biurquer: Il n’y a pas d’alternative (Bifurcate: There Is No Alternative) on the scientific, technological and political stakes of the notion of entropy. The discussion took place between Bernard Stiegler, Maël Montévil, Marie Chollat-Namy and Victor Chaix, on the 1st of July 2020.