Repetition and Variability in Urban Travel

Most travel models and theories assume the existence of habitual behavior, yet few empirical studies have examined the question of how much repetition or variability characterizes daily travel. We first review the arguments for expecting both repetition and variability in urban travel-activity patterns and then conduct an empirical analysis of repetition and variability in travel over a five-week period. The results show that, whereas many behaviors that make up the daily pattern are highly repetitious (they occur with high frequency over the 35 days), the similarity between daily travel patterns on different days in an individual's longitudinal record is quite low. Even the day that is the most typical of the individual's travel is a poor indicator of that person's overall travel pattern. Moreover, we found that each person generates several archetypical daily patterns over 35 days, and this finding has important implications for data collection and modeling in studies of urban travel.     

From stone to metal: New perspectives on the later prehistory of West Africa

Earlier views saw West Africa as culturally stagnant through much of the Holocene until stimulus or intervention from north of the Sahara transformed Iron Age societies. Evidence accumulating over the past 15 years suggests that stone-using societies from 10,000 to 3000 B.P. were far more diverse than previously thought. Against an increasingly detailed record of Holocene climate change, the complexity of local adaptation and change is becoming better understood. Although a strong case currently exists for the introduction of copper and iron to West Africa from the north in the mid-first millennium B.C., the subsequent development of metallurgy was strongly innovative in different parts of the subcontinent. Soon after the advent of metals, a dramatic increase in archaeological evidence for social stratification and hierarchical political structures indicates the emergence of societies markedly more complex than anything currently documented in the Late Stone Age. The best-documented examples come from the Middle Niger region and the Nigerian forest. In these areas, earlier diffusionist models in which complexity originated outside West Africa have yielded to evidence that indigenous processes were instrumental in this transformation. Trade, ideology, climate shifts, and indirect influences from North Africa, including the introduction of the domesticated horse to the Sahelian grasslands, are identified as factors essential to an understanding of these processes.     

Acts of severity: colonial settler massacre of amaXhosa and abaThembu on the eastern frontier of the Cape Colony,c.1826–47

Colonial massacre of the amaXhosa and abaThembu on the Cape Colony's eastern frontier between the 1820s and 1840s appears to be neglected compared to the extermination of the Khoisan. Whereas revisionist histories—most of which use an indigenous-resistance framework—have concentrated on Xhosa resistance to settler expansion, little attention has been paid to settler massacre. This article examines selected massacres between 1826 and 1847, considers their etiology, situates them within current debates on colonial settler genocide, and questions the success of Buxton's Select Committee on Aborigines in ending them.