2 resultados para attrition and chipping
em Duke University
Resumo:
Paleoprimatologists depend on relationships between form and function of teeth to reconstruct the diets of fossil species. Most of this work has been limited to studies of unworn teeth. A new approach, dental topographic analysis, allows the characterization and comparison of worn primate teeth. Variably worn museum specimens have been used to construct species-specific wear sequences so that measurements can be compared by wear stage among taxa with known differences in diet. This assumes that individuals in a species tend to wear their molar teeth in similar ways, a supposition that has yet to be tested. Here we evaluate this assumption with a longitudinal study of changes in tooth form over time in primates. Fourteen individual mantled howling monkeys (Alouatta palliata) were captured and then recaptured after 2, 4, and 7 years when possible at Hacienda La Pacifica in Costa Rica between 1989-1999. Dental impressions were taken each time, and molar casts were produced and analyzed using dental topographic analysis. Results showed consistent decreases in crown slope and occlusal relief. In contrast, crown angularity, a measure of surface jaggedness, remained fairly constant except with extreme wear. There were no evident differences between specimens collected in different microhabitats. These results suggest that different individual mantled howling monkeys wear their teeth down in similar ways, evidently following a species-specific wear sequence. Dental topographic analysis may therefore be used to compare morphology among similarly worn individuals from different species.
Resumo:
Deep societal trends impact the religious fervency and participation of millennials in the Black Church. Many young adults, though remaining Christian, have fallen away from their faith communities, finding them irrelevant for their daily lives. Even the most religiously committed have shown signs of waning faith, as evidenced by limited participation, and theological and ideological dissonance with the Black Church. Historically strong across all indicators, the Black Church is ideally positioned to stave off the attrition of youth and young adults, having a missional mindset toward this cohort—prioritizing them in their ministry development and programming. African American congregational leaders must develop disciples who have cohesive identities, live integrated lives, and experience an infusion of their personal vocation and the mission of the Church. Thus the future of the Black Church depends on the development of millennials who have an integrated faith life, which is distinguishable by its practices, disciplines, and virtues that are nurtured by an understanding of the Church’s mission and their role in it. Key will be establishing mentoring relationships that allow for questioning, exploration and discovery. To enact the changes necessary the church must understand the cultural worlds of young adults and engage them in holistic ministry that is reflective of the mission of God through Christ (missio dei)—activity that culminates with reaching the world with God’s redemptive plan for humanity.