首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12篇
  免费   0篇
  2020年   1篇
  2014年   2篇
  2013年   1篇
  2012年   1篇
  2007年   1篇
  2006年   2篇
  2002年   1篇
  1999年   1篇
  1997年   1篇
  1980年   1篇
排序方式: 共有12条查询结果,搜索用时 31 毫秒
11.
This paper explores the interplay of local state action with historical contingency, innovation and external economies in the world's largest tobacco-producing region – Yunnan, China. Formed in a relatively unindustrialized province and promoted by local authorities as their primary revenue base, Yunnan's tobacco economy gained a headstart through concentrated resource support and ad hoc regulatory flexibility. Its further growth has drawn greatly on intraregional spillovers of knowledge of locally based institutional innovation, which foster and enhance conventional forms of external economies. Implications for the study of regional economies are discussed.  相似文献   
12.
The search for the origins of syphilis has a long history in the medical and anthropological literatures. If we know more about the emergence of the pathogen that causes the disease in humans we will understand its evolution through time and space as well as shed light on its current state in living populations. Ancient DNA techniques used to isolate Treponema pallidum subsp. pallidum DNA from archaeological human specimens provide direct evidence of its existence in the past. However to date, only Kolman et al. (1999) have been successful in this endeavour, while other attempts have failed (e.g., Barnes and Thomas, 2006; Bouwman and Brown, 2005). Why has there been little success? This paper serves to compliment and add relevant information to Bouwman and Brown's and Barnes and Thomas' discussion concerning our inability to apply ancient DNA techniques to study venereal syphilis in past human populations.Our approach utilized 15 different human specimens from different geographies and different temporal periods: eight samples come from medically diagnosed individuals archived during the American Civil War period; six originate from the United Kingdom and predate 1492 with four of these samples having been previously analyzed by Bouwman and Brown and one sample comes from historic Canada. Human mitochondrial and amelogenin DNA, as well as several genes from the Treponema organism were analyzed revealing the relatively good preservation of human multi-copy and single copy DNA but not treponemal DNA. This study also incorporates a unique molecular experiment using rabbits infected with venereal syphilis to help illustrate that treponemal DNA disseminates to bone early during the first stages of infection but is not present in later stages of the disease using the techniques presented in this study.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号