Re-Evaluation of Sinocastor (Rodentia: Castoridae) with Implications on the Origin of Modern Beavers

The extant beaver, Castor, has played an important role shaping landscapes and ecosystems in Eurasia and North America, yet the origins and early evolution of this lineage remain poorly understood. Here we use a geometric morphometric approach to help re-evaluate the phylogenetic affinities of a fossil skull from the Late Miocene of China. This specimen was originally considered Sinocastor, and later transferred to Castor. The aim of this study was to determine whether this form is an early member of Castor, or if it represents a lineage outside of Castor. The specimen was compared to 38 specimens of modern Castor (both C. canadensis and C. fiber) as well as fossil specimens of C. fiber (Pleistocene), C. californicus (Pliocene) and the early castorids Steneofiber eseri (early Miocene). The results show that the specimen falls outside the Castor morphospace and that compared to Castor, Sinocastor possesses a: 1) narrower post-orbital constriction, 2) anteroposteriorly shortened basioccipital depression, 3) shortened incisive foramen, 4) more posteriorly located palatine foramen, 5) longer rostrum, and 6) longer braincase. Also the specimen shows a much shallower basiocciptal depression than what is seen in living Castor, as well as prominently rooted molars. We conclude that Sinocastor is a valid genus. Given the prevalence of apparently primitive traits, Sinocastor might be a near relative of the lineage that gave rise to Castor, implying a possible Asiatic origin for Castor

3D Morphometric and Posture Study of Felid Scapulae Using Statistical Shape Modelling

We present a three dimensional (3D) morphometric modelling study of the scapulae of Felidae, with a focus on the correlations between forelimb postures and extracted scapular shape variations. Our shape modelling results indicate that the scapular infraspinous fossa becomes larger and relatively broader along the craniocaudal axis in larger felids. We infer that this enlargement of the scapular fossa may be a size-related specialization for postural support of the shoulder joint

Pour profiter de la fraicheur des arbres : les aider à s'adapter au climat.

Faire un câlin aux arbres : cette pratique de la sylvothérapie, en vogue ces dernières années témoigne du bien-être émotionnel que nous procurent les arbres. Leur capacité à rafraîchir le climat de la cité et de moduler celui de notre planète, est un autre service, physique cette fois-ci, qu’ils nous rendent. Pour autant qu’ils puissent rester en vie face au changement climatique. Et c’est à l’Homme de les y accompagner. Explications avec, en guise d’exemple, le déploiement du Plan canopée de la ville de Lyon

UV-induced reaction of H₂ with the core of germanosilicate and aluminosilicate fiber preforms

The photosensitivity of glasses can be significantly enhanced by high-pressure low-temperature hydrogen loading prior to UV exposure. The chemical reactions that occur between hydrogen and glass under UV exposure are thus of primary importance for the understanding of the mechanisms of H2 photosensitivity enhancement. We have used infrared spectroscopy to characterize the microstructural modifications in H2-loaded optical fiber preform cores exposed to UV laser light. Infrared spectroscopy in the 3µm range is very well adapted to such a characterization because it is highly sensitive to hydroxyl groups

Biaxial deformation of polyamide-6: Assesment of orientation by means of infrared trichroism

International audienc

Biaxial deformation of polyamide-6: Assesment of orientation by means of infrared trichroism

International audienc

Biaxial deformation of polyamide-6: Assesment of orientation by means of infrared trichroism

International audienc

Biaxial deformation of polyamide-6: Assessment of orientation by means of infrared trichroism

International audienc