How can research on modern and fossil bones help us build more resistant columns?

Bone is an economical material. Indeed, as moving a heavy skeleton is energetically costly, the vertebrate skeleton is adapted to maximise resistance to the stresses imposed with a minimum amount of material, so that bone tissue is deposited where it is needed. Using bone as a source of inspiration should therefore reduce the manufacturing cost (both financial and ecological) and increase the strength (and lifespan) of bioinspired (BI) structures. This study proposes to investigate which adaptive features of the outer shape and inner structure of bone, related to compressive strength, could be used to build BI support structures. To do so, we explain the choice of the bones to be analysed and present the results of the biomechanical analyses (finite element analysis) carried out on virtual models built from the structures of the different bone models and of the mechanical tests carried out on 3D-printed versions of these models. The compressive strength of these direct bone BI columns was compared with each other, and with those of a conventional filled cylindrical column, and of a cylindrical column whose internal structure is BI from the radius of the white rhinoceros. The results of our comparative analyses highlight that the shape of long bones is less effective than a cylinder in resisting compression but underline the relevance in designing BI cylindrical columns with heterogeneous structures inspired by the radius of the white rhinoceros and the tibia of the Asian elephant, and raise the interest in studying the fossil record using the radius of the giant rhinocerotoidParaceratherium.

Regulation of dietary fat preference: establishing a reproducible profile of dietary fat preference in rats.

The mechanism(s) underlying preference for individual macronutrients (particularly fat) in diet are poorly understood. The greatest obstacle in designing experiments to define neurochemical determinants of fat preference lies in our ability to clearly identify animals' macronutrient preference (MP) profile. To this end, we have defined the role of several variables and suggested ways to design better studies to examine the mechanism of macronutrient preference. The results of these studies show that the paradigm used for MP analysis, genetics and age of the animal could clearly affect the MP profile.