Genomic ancestry and social dynamics of the last hunter-gatherers of Atlantic France.

Since the early Holocene, western and central Europe was inhabited by a genetically distinct group of Western Hunter-Gatherers (WHGs). This group was eventually replaced and assimilated by the incoming Neolithic farmers. The western Atlantic façade was home to some of the last Mesolithic sites of mainland Europe, represented by the iconic open-air sites at Hoedic and Téviec in southern Brittany, France. These sites are known for the unusually well-preserved and rich burials. Genomic studies of Mesolithic European hunter-gatherers have been limited to single or a few individuals per site and our understanding of the social dynamics of the last Mesolithic hunter-gatherers of Europe and their interactions with incoming farmers is limited. We sequenced and analyzed the complete genomes of 10 individuals from the Late Mesolithic sites of Hoedic, Téviec, and Champigny, in France, four of which sequenced to between 23- and 8-times genome coverage. The analysis of genomic, chronological and dietary data revealed that the Late Mesolithic populations in Brittany maintained distinct social units within a network of exchanging mates. This resulted in low intra-group biological relatedness that prevented consanguineous mating, despite the small population size of the Late Mesolithic groups. We found no genetic ancestry from Neolithic farmers in the analyzed hunter-gatherers, even though some of them may have coexisted with the first farming groups in neighboring regions. Hence, contrary to previous conclusions based on stable isotope data from the same sites, the Late Mesolithic forager community was limited in mate-exchange to neighboring hunter-gatherer groups, to the exclusion of Neolithic farmers.

Teaching Style Preferences and Online Teaching Practices of Optometry Teachers During COVID-19: A Preliminary Study.

Purpose: Although research on teaching style preferences is available in the literature, there is limited information on the preferences of optometry teachers. The Coronavirus disease 2019 pandemic has impacted educational practices in all sectors. This study focuses on the teaching style preferences and online teaching practices of optometry teachers during the COVID-19 pandemic. Patients and Methods: The study used a case study research design and a self-administered online questionnaire and follow-up semi-structured interview for data collection. The Grasha-Riechmann teaching style inventory was used to explore the teaching style preferences (Expert, Formal Authority, Demonstrator, Facilitator and Delegator). Quantitative and qualitative data were analyzed using descriptive statistics and thematic content analysis respectively. Results: The optometry teachers were aged between 29 and 51 years (median = 45 years) and had between 3 and 25 years of teaching experience (median = 5 years). All teachers scored high in the Expert teaching style and most had scores categorized as high for the Delegator, Facilitator and Formal Authority teaching styles. The teachers reported that the initial adaptation to online teaching was difficult and challenging as they were not prepared for the rapid transition to online learning. They used various resources and materials but felt that student participation and engagement was lower in online teaching. Teachers noted that more time was needed to prepare materials for online teaching than for face-to-face teaching. Conclusion: Optometry teachers adopted a multidimensional approach preferring the different teaching styles to varying degrees. Teachers noted challenges with the initial transition and adaptation to online teaching and used a combination of resources to support student learning.