The Neanderthal teeth from Marillac (Charente, Southwestern France): Morphology, comparisons and paleobiology

Few European sites have yielded human dental remains safely dated to the end of MIS 4/beginning of MIS 3. One of those sites is Marillac (Southwestern France), a collapsed karstic cave where archeological excavations (1967–1980) conducted by B. Vandermeersch unearthed numerous faunal and human remains, as well as a few Mousterian Quina tools. The Marillac sinkhole was occasionally used by humans to process the carcasses of different prey, but there is no evidence for a residential use of the site, nor have any hearths been found. Rare carnivore bones were also discovered, demonstrating that the sinkhole was seasonally used, not only by Neanderthals, but also by predators across several millennia. The lithostratigraphic units containing the human remains were dated to ∼60 kyr. The fossils consisted of numerous fragments of skulls and jaws, isolated teeth and several post-cranial bones, many of them with traces of perimortem manipulations. For those already published, their morphological characteristics and chronostratigraphic context allowed their attribution to Neanderthals. This paper analyzes sixteen unpublished human teeth (fourteen permanent and two deciduous) by investigating the external morphology and metrical variation with respect to other Neanderthal remains and a sample from modern populations. We also investigate their enamel thickness distribution in 2D and 3D, the enamel-dentine junction morphology (using geometric morphometrics) of one molar and two premolars, the roots and the possible expression of taurodontism, as well as pathologies and developmental defects. The anterior tooth use and paramasticatory activities are also discussed. Morphological and structural alterations were found on several teeth, and interpreted in light of human behavior (tooth-pick) and carnivores' actions (partial digestion). The data are interpreted in the context of the available information for the Eurasian Neanderthals

Surface and electrochemical characterization of Ni-Zr intermetallic compounds

In this paper the Ni-Zr system has been considered with the aim of investigating the role of composition and structure of an early-late transition metals system on the electrocatalytic activity, for the hydrogen evolution reaction. As a matter of fact, pure Ni and Zr show low activity, while their intermetallic compounds generate a higher catalytic efficiency. Five alloys, with increasing Ni content starting from Ni33Zr67 up to Ni75Zr25, have been prepared and characterized. The alloy of composition (Ni0.55Mn0.30V0.10Co0.05)2.1Zr has also been considered, in order to investigate the catalytic efficiency related to a Laves structure. The thickness and composition of the surface oxides have been investigated and their effect on reducing the catalytic efficiency of the as-prepared alloys has been discussed. The activity of the samples submitted to a surface activation treatment with hydrofluoric acid, that removes the oxide layer and allows to evidence the properties of the compounds, has been observed to increase significantly. The trend of the electrocatalytic efficiency with the composition of the alloys is discussed considering a synergetic effect between Ni and Zr. The Laves phase appears slightly more active than the binary intermetallic compound