41. Subsequent more accurate dating using stratification layers of the cave. 42. Selected occupations include agriculturists, herders, hierarchichal stratification within the empire. 43. But another kind of stratification is taking place, Plumpp and others say. 44. The airlines defend the new stratification as a necessary nod to customer relations. 45. Despite that social stratification exists in the Sikh community. 46. Greater degrees of social stratification appeared in agrarian societies. 47. When Ri is large, turbulent mixing across the stratification is generally suppressed. 48. Breakdown of thermal stratification is frequently driven by the cooling overnight air temperature. 49. An index of stratification has been recently proposed by Zhou for this purpose. 50. Their societies may also have had a somewhat lower level of social stratification .