Dental microwear texture analysis of Homo sapiens sapiens: Foragers, farmers, and pastoralists.

OBJECTIVES: The current study seeks to determine if a sample of foragers, farmers, and pastoralists are distinguishable based on their dental microwear texture signatures. MATERIALS AND METHODS: The study included a sample of 719 individuals from 51 archeological sites (450 farmers, 192 foragers, 77 pastoralists). All were over age 12 and sexes were pooled. Using a Sensofar® white-light confocal profiler we collected dental microwear texture analysis (DMTA) data from a single first or second molar from each individual. We leveled and cleaned data clouds following standard procedures and analyzed the data with Sfrax® and Toothfrax® software. The DMTA variables were complexity and anisotropy. Statistics included ANOVA with partial eta squared and Hedges's g. We also performed a follow-up K-means cluster analysis. RESULTS: We found significant differences between foragers and farmers and pastoralists for complexity and anisotropy, with foragers having greater complexity than either the farmers or the pastoralists. The farmers and pastoralists had greater anisotropy than the foragers. The Old World foragers had significantly higher anisotropy values than New World foragers. Old and New World farmers did not differ. Among the Old World farmers, those dating from the Neolithic through the Late Bronze Age had higher complexity values than those from the Iron Age through the medieval period. The cluster analysis discerned foragers and farmers but also indicated similarity between hard food foragers and hard food farmers. DISCUSSION: Our findings reaffirm that DMTA is capable of distinguishing human diets. We found that foragers and farmers, in particular, differ in their microwear signatures across the globe. There are some exceptions, but nothing that would be unexpected given the range of human diets and food preparation techniques. This study indicates that in general DMTA is an efficacious means of paleodietary reconstruction in humans.

Poor hand hygiene by college students linked to more occurrences of infectious diseases, medical visits, and absence from classes.

BACKGROUND: Proper hand hygiene has been linked to lower susceptibility to infectious diseases in many types of communities, but it has not been well established on college campuses. This study investigated the hand hygiene statuses of college students and their occurrences in relation to infectious diseases, medical visits, and absence from classes or work. It also examined the effects of education on handwashing technique to improve hand hygiene. METHODS: College students enrolled at a university in Northwestern Ohio were recruited as study subjects. Microbial samples were collected 3 times from each of the 220 valid volunteers before washing their hands, after washing with their own procedures, and after washing with a procedure recommended by the Centers for Disease Control and Prevention (CDC). Each volunteer also answered a survey including questions on their health conditions, medical visits, and absence from classes or work. RESULTS: Hands of 57.7% volunteers were colonized by an uncountable number of microbial colonies, which were significantly linked to more occurrences to infectious diseases (P < .05), medical visits (P < .05), and arguably more absence from classes or work (P = .09). The handwashing procedure provided by the CDC significantly improved hand hygiene. CONCLUSION: It is critical to promote education on proper handwashing in colleges, in grade schools, and at home to improve health and learning outcomes.