6 Access Methods and Query Processing Techniques

The performance of a database management system (DBMS) is fundamentally dependent on the access methods and query processing techniques available to the system. Traditionally, relational DBMSs have relied on well-known access methods, such as the ubiquitous B +-tree, hashing with chaining, and, in som

Regulatory Variation at Glypican-3 Underlies a Major Growth QTL in Mice

The genetic basis of variation in complex traits remains poorly understood, and few genes underlying variation have been identified. Previous work identified a quantitative trait locus (QTL) responsible for much of the response to selection on growth in mice, effecting a change in body mass of approximately 20%. By fine-mapping, we have resolved the location of this QTL to a 660-kb region containing only two genes of known function, Gpc3 and Gpc4, and two other putative genes of unknown function. There are no non-synonymous polymorphisms in any of these genes, indicating that the QTL affects gene regulation. Mice carrying the high-growth QTL allele have approximately 15% lower Gpc3 mRNA expression in kidney and liver, whereas expression differences at Gpc4 are non-significant. Expression profiles of the two other genes within the region are inconsistent with a factor responsible for a general effect on growth. Polymorphisms in the 3′ untranslated region of Gpc3 are strong candidates for the causal sequence variation. Gpc3 loss-of-function mutations in humans and mice cause overgrowth and developmental abnormalities. However, no deleterious side-effects were detected in our mice, indicating that genes involved in Mendelian diseases also contribute to complex trait variation. Furthermore, these findings show that small changes in gene expression can have substantial phenotypic effects

“But it is not getting any safer!”: The contested dynamic of framing Canada's military mission in Afghanistan

The Canadian government and military struggled to control its media framing of the war in Afghanistan between 2006 and 2009. This content analysis (n = 900) critically investigates the mediated dynamic of framing Canada's military mission in Afghanistan. This study found that while journalists overwhelmingly indexed their stories to elite sources, they frequently impeached the frames sponsored by government and military leaders. Journalists used elite criteria to fact check the frames of military and government leaders. Most of the coverage was episodic and event-oriented rather than thematic and contextual. While Canadian journalists challenged official claims of improving security, for instance, their coverage lacked context and critical appraisal of Canada's military mission in Afghanistan, raising questions about journalism's normative role in Canadian democracy