Hybridization of Poly(oxazoline) and Poly(ethylene oxide)-Based Amphiphilic Copolymers into Thermosensitive Mixed Micelles of Tunable Cloud Point

This paper reports the development in aqueous solution of mixed micelles of tunable cloud point temperature through blending in various proportions of two copolymers of different chemical natures. For that purpose, a lipid-b-poly(2-isopropyl-2-oxazoline) (lipid-b-P(iPrOx)) copolymer, self-assembling into thermosensitive micelles that phase-separate above a cloud point temperature of 38 °C, was blended in various proportions with commercial C18-b-PEOx. The latter was constituted of a hydrophobic saturated C18 chain and a hydrophilic poly(ethylene oxide) (PEO) block with varying polymerization degrees (x) and does not have any thermosensitive properties on the studied temperature range for any value of x. The different blends were thoroughly characterized by light scattering and UV–visible spectroscopy, revealing that hybridization between both copolymers always occurred, independent of the PEO block length. The resulting mixed micelles present TCP values progressively increasing with the C18-b-PEOx proportion, from 38 to 61 °C. This study demonstrates the relevance of the blending approach to tune the phase separation of micellar systems by formulation rather than by more tedious synthetic efforts. Shifting TCP through this approach extends the range of temperature where lipid-b-P(iPrOx) can find an application

The “Cayo” Site of Roseau: Ceramic, vertebrate and isotopic analysis of a Guadeloupe Late Ceramic archaeological assemblage

The Cayo archaeological deposits documenting the contact period between European and Amerindian populations before the colonization of the Lesser Antilles are rare. Among the few sites dated to this period, the site of Roseau, excavated by Gérard Richard in the early 2000s, remains poorly investigated, especially from a stratigraphic and zooarchaeological point of view. In this study, we performed 20 new radiocarbon datings on the collagen content of rodent dentin along with new studies of the ceramic and faunal assemblages of the site. The results indicate that the archaeological assemblage is mainly associated to the Late Troumassoid, with some admixture of Early Troumassoid and Cayo elements represented in various proportions in the whole stratigraphy. Despite these elements, a chronological trend appears preserved in the stratigraphy allowing for a research of behavioral change in subsistence pattern through time. Vertebrate faunal data indicate that the two Troumassoid layers we recognized document different subsistence strategies. Indeed, the earliest inhabitants of the site were more focused on the exploitation of aquatic resources than the latest ones who more significantly exploited terrestrial fauna, especially rodents and iguanas. Carbon and oxygen stable isotope analyses performed on fossil tooth enamel of rodents (Antillomys rayi) suggest that Amerindians hunted them in both dry and wet environments. Paleontological approaches also led to the discovery of several now-extinct taxa that were part of the Amerindian diet. Our investigations point to a strong chronological variability of subsistence behaviors and improve our understanding of the accumulation history of the site.Ecosystèmes insualires tropicaux : réponse de la biocénose animale terrestre à6 000 ans d'anthropisatio

The pre-Columbian site of Roseau (Guadeloupe, F. W. I.): intra-site chronological variability of the subsistence strategies in a Late Ceramic archaeological vertebrate assemblage

Evidence for chronological change in intra-site subsistence strategies is very rare in the Amerindian record of the Lesser Antilles. The study of the vertebrate assemblage from the archaeological site of Roseau in the Guadeloupe Islands underlines the complexity and variability of Ceramic Age Amerindian subsistence behavior. This study establishes a more precise chronology of the previously identified strata of the site, and demonstrates that the Contact period was only represented by rare archaeological artifacts dispersed in the stratigraphy. The results from this assemblage indicate that the earlier occupations of the site exhibit a more intensive exploitation of aquatic vertebrate resources compared to later occupations, which have a larger focus on terrestrial fauna, especially rodents and iguanas. This unusual pattern highlights how subsistence behaviors in the Lesser Antilles during the Late and Final Ceramic periods were highly variable. This new evidence of strong inter-site variability shows that the behaviors of Amerindians are not only dependent of large scale environmental conditions but are also influenced by more complex socio-cultural and local environmental parameters

Evolution of the Incidence of Oral Cavity Cancers in the Elderly from 1990 to 2018

Objectives: To describe the evolution of the incidence of oral cavity cancers (OCC) among elderly patients in France between 1990 and 2018 and to compare it to the incidence of other cancers sharing the same main risk factors. Material and Methods: The incidence of cancers in mainland France from 1990 to 2018 was estimated from incidence data observed in every cancer registry of the Francim network. Incidence was modeled by a 2-dimensional penalized spline of age and year of diagnosis, associated with a random effect corresponding to the registry. The elderly population was divided into two groups: 70–79 years old and ≥80 years old. Results: There was a 72% increase in the number of OCC cases in women over 70 years of age between the periods 1990–1999 and 2010–2018. As for men, there was a stabilization in the number of cases (+2%). Over the same period, for laryngeal and hypopharyngeal cancers, there was a decrease in incidence in elderly men and an increase in elderly women, although less marked than for OCC. Conclusions: Since the 1990s, the incidence of OCC has been increasing in elderly subjects in France, particularly in women. Population aging and growth or alcohol and tobacco consumption alone do not seem to explain this increase, which is not observed in the same proportions for other upper aerodigestive tract cancer subsites sharing the same main risk factors