Enhanced gene trapping in mouse embryonic stem cells

Gene trapping is used to introduce insertional mutations into genes of mouse embryonic stem cells (ESCs). It is performed with gene trap vectors that simultaneously mutate and report the expression of the endogenous gene at the site of insertion and provide a DNA tag for rapid identification of the disrupted gene. Gene traps have been employed worldwide to assemble libraries of mouse ESC lines harboring mutations in single genes, which can be used to make mutant mice. However, most of the employed gene trap vectors require gene expression for reporting a gene trap event and therefore genes that are poorly expressed may be under-represented in the existing libraries. To address this problem, we have developed a novel class of gene trap vectors that can induce gene expression at insertion sites, thereby bypassing the problem of intrinsic poor expression. We show here that the insertion of the osteopontin enhancer into several conventional gene trap vectors significantly increases the gene trapping efficiency in high-throughput screens and facilitates the recovery of poorly expressed genes

AGMAAS: a GIS integrated tool for modelling wind-borne spreading of FMD virus

The aim of our work was to develop a tool integrated into Quantum GIS (QGIS) that can help
the user estimate and visualize the possible infective areas around an outbreak based on HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model

Tax Fairness

This Article argues that, contrary to the consensus of economists and many legal scholars, the norm of horizontal equity in taxation has independent meaning as a default rule in favor of existing arrangements. Although it has long been said, and widely thought, that tax should be fair in its dealings with individuals who are situated similarly to one another, no one has been able to say convincingly just what that fairness comprises. As a result, the learned referees in the last major dispute over the significance of horizontal equity judged that fairness\u27s critic had decidedly won the day. Since then, there have been ever more critics, but no cogent, comprehensive defense. My defense is both theoretical and practical. First, I argue that horizontal equity is a special aspect of the revenue function in taxation. Because it enshrines the status quo before enactment of a new tax law, horizontal equity can be reconceived as a commitment by the authors of tax legislation to honor the past and future policy choices of others, with whom they are jointly engaged in a project of deliberative democracy. Alternately, horizontal equity may bejustfied by welfare gains from a shared agreement to leave certain controversial questions of distributive justice undecided during the revenue-raisingp rocess. Both oft hese rationalesl eave open-indeed,t hey clear the air for-arguments about the ultimate ends law, and tax law in particular, should serve in society