The spread of early iron-producing communities in Eastern and Southern Africa

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Rural and Urban Differences in Welfare Exits: Minnesota Evidence 1986-1996

This article examines differences between rural and urban counties in the duration of welfare spells. We report evidence that suggests that parents from farming-dependent counties and rural counties are more likely to have shorter spells on welfare. The evidence appears consistent with the literature on rural low-income families in that there may be a concentration of low-wage jobs in rural counties. The difference between rural and urban areas is relevant to welfare policy as it pertains to caseload numbers, parents more likely to reach the sixty-month time limit, and parents more likely to trigger time-based policies, such as employment search. The study uses administrative data of Aid to Families With Dependent Children recipients from the state of Minnesota between 1986 and 1996. The methodology includes constructing descriptive statistics, calculating Kaplan-Meier estimates, and performing a Cox regression analysis with robustness checks across all three methods. Copyright 2005 Blackwell Publishing Ltd..

Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic

The Rio Grande Cone is a large-scale fanlike feature in the continental slope of the Pelotas Basin, Southern Brazil, where ubiquitous world-class bottom simulating reflectors (BSRs) are readily observed in seismic records. With the purpose of searching for natural gas hydrate deposits in the Cone area, four oceanographic cruises were carried out between May 2011 and July 2013, leading to the discovery of two pockmark fields, active faults and gas hydrates in shallow sediments. Multichannel seismic, multibeam echo sounder, side scan sonar and sub-bottom profiler records were used to map the shallow section and select sites for piston core sampling. Gas hydrates were recovered in several piston cores within muddy sediments collected inside pockmarks displaying high backscatter in the multibeam and side scan sonar data. We present two representative piston cores where numerous levels of gas hydrates occur, along with degassing features, authigenic carbonate and soupy sediments. Gas dissociated from gas hydrate samples is dominantly methane (&gt;99.78%) with minor quantities of ethane. The chemical and isotopic compositions of the gas strongly suggest a biogenic origin for the analyzed samples. These new findings are regarded as strong enough evidence to consider the Rio Grande Cone as a new gas hydrate province. (C) 2015 Elsevier Ltd. All rights reserved.</p