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Estimation in linear models with censored data 总被引:1,自引:0,他引:1
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HAROLD K. SCHNEIDER 《American anthropologist》1977,79(1):9-25
Employing genetic theory as an analog, the paper argues that when the concept of culture is separated from the concept of society, anthropology can be shown to have depended for culture-change theory on a genetic model, which predicts pre-Columbian contact between the Old and New World, a prediction which is supported by a growing list of cultural parallels . [prehistoric transpacific contact, culture, society, culture change, scientific explanation] 相似文献
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THERESE F. MOE ANNE K. BRYSTING TOM ANDERSEN SUSANNE C. SCHNEIDER ØYVIND KASTE DAG O. HESSEN 《Freshwater Biology》2013,58(1):114-127
1. Invasive species can transform aquatic ecosystems, and the nuisance growth of the freshwater macrophyte Juncus bulbosus has become a problem in many lakes and rivers in northern Europe. It affects biodiversity strongly and conflicts with human uses, not least compromising the generation of hydroelectricity. The causes of the proliferation of these massive stands of J. bulbosus are not finally resolved, however. 2. In this study, a wide range of catchment, lake and sediment parameters (n = 34) were assessed for 139 lakes in Southern Norway, with the aim of explaining the presence or absence of J. bulbosus and to assess potential drivers behind its prolific growth. 3. Juncus bulbosus was more often present in lakes with lower pH and phosphate concentrations, and a higher element ratio of dissolved inorganic nitrogen (DIN) to total phosphorus (DIN : TotP). 4. Despite the many parameters measured across substantial environmental gradients, none explained nuisance growth. Genetic screening (amplified fragment length polymorphism fingerprinting) of plants from a subset of lakes and additional river sites also showed no genetic differences between the various growth forms. A macrophyte trophic index, however, suggested that the most problematic growth occurred in the most oligotrophic lakes. 5. The lack of consistent patterns may reflect either factors not assessed in our survey, or that the current extension of stands represents a gradual cumulative response over time, not characterised effectively in our snapshot survey. Nevertheless, we can now exclude some putative causes of nuisance growth, including in particular genetics and N‐deposition. 相似文献
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CLARE J. HOPKINS NOEL O. I. COGAN MELANIE HAND ERICA JEWELL JATINDER KAUR XI LI GERALDINE A. C. LIM ALISON E. LING CHRISTOPHER LOVE HAYLEY MOUNTFORD MARIJA TODOROVIC MEGAN VARDY GERMAN C. SPANGENBERG DAVID EDWARDS JACQUELINE BATLEY 《Molecular ecology resources》2007,7(4):697-700
The availability of expressed sequence data derived from gene discovery programs enables mining for simple sequence repeats (SSR), providing useful genetic markers for crop improvement. These markers are inexpensive, require minimal labour to produce and can frequently be associated with functionally annotated genes. This study presents the development and characterization of 16 expressed sequence tags (EST)‐SSR markers from Brassica juncea and their cross‐amplification across Brassica species. Sixteen primer pairs were assessed for polymorphism in all genomes of the diploid and amphidiploid Brassica species. The markers show reliable amplification, considerable polymorphism and high transferability across species, demonstrating the utility of EST‐SSRs for genetic analysis of brassicas. 相似文献
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JACQUELINE BATLEY CLARE J. HOPKINS NOEL O. I. COGAN MELANIE HAND ERICA JEWELL JATINDER KAUR SUKHJIWAN KAUR XI LI ALISON E. LING CHRISTOPHER LOVE HAYLEY MOUNTFORD MARIJA TODOROVIC MEGAN VARDY MARZENA WALKIEWICZ GERMAN C. SPANGENBERG DAVID EDWARDS 《Molecular ecology resources》2007,7(5):886-889
The availability of expressed sequence data derived from gene discovery programs enables mining for simple sequence repeats (SSR), providing useful genetic markers for crop improvement. These markers are inexpensive, require minimal labour to produce and can frequently be associated with functionally annotated genes. This study presents the development and characterization of 24 expressed sequence tags (EST)‐SSR markers from Brassica napus and their cross‐amplification across Brassica species. The markers show reliable amplification, genome specificity and considerable polymorphism, demonstrating the utility of EST‐SSRs for genetic analysis of wild Brassica populations and commercial Brassica germplasm. 相似文献
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