2 resultados para high- to low-grade mylonitization
em Boston University Digital Common
Resumo:
Studies suggest that income replacement is low for many workers with serious occupational injuries and illnesses. This review discusses three areas that hold promise for raising benefits to workers while reducing workers' compensation costs to employers: improving safety, containing medical costs, and reducing litigation. In theory, workers' compensation increases the costs to employers of injuries and so provides incentives to improve safety. Yet, taken as a whole, research does not provide convincing evidence that workers' compensation reduces injury rates. Moreover, unlike safety and health regulation, workers' compensation focuses the attention of employers on individual workers. High costs may lead employers to discourage claims and litigate when claims are filed. Controlling medical costs can reduce workers' compensation costs. Most studies, however, have focused on costs and have not addressed the effectiveness of medical care or patient satisfaction. Research also has shown that workers' compensation systems can reduce the need for litigation. Without litigation, benefits can be delivered more quickly and at lower costs.
Resumo:
BACKGROUND:Recent advances in genome sequencing suggest a remarkable conservation in gene content of mammalian organisms. The similarity in gene repertoire present in different organisms has increased interest in studying regulatory mechanisms of gene expression aimed at elucidating the differences in phenotypes. In particular, a proximal promoter region contains a large number of regulatory elements that control the expression of its downstream gene. Although many studies have focused on identification of these elements, a broader picture on the complexity of transcriptional regulation of different biological processes has not been addressed in mammals. The regulatory complexity may strongly correlate with gene function, as different evolutionary forces must act on the regulatory systems under different biological conditions. We investigate this hypothesis by comparing the conservation of promoters upstream of genes classified in different functional categories.RESULTS:By conducting a rank correlation analysis between functional annotation and upstream sequence alignment scores obtained by human-mouse and human-dog comparison, we found a significantly greater conservation of the upstream sequence of genes involved in development, cell communication, neural functions and signaling processes than those involved in more basic processes shared with unicellular organisms such as metabolism and ribosomal function. This observation persists after controlling for G+C content. Considering conservation as a functional signature, we hypothesize a higher density of cis-regulatory elements upstream of genes participating in complex and adaptive processes.CONCLUSION:We identified a class of functions that are associated with either high or low promoter conservation in mammals. We detected a significant tendency that points to complex and adaptive processes were associated with higher promoter conservation, despite the fact that they have emerged relatively recently during evolution. We described and contrasted several hypotheses that provide a deeper insight into how transcriptional complexity might have been emerged during evolution.