introduction: the purpose of this study was to compare first accessory gutta-percha penetration after the use of nickel-titanium (ni-ti) or stainless-steel spreaders in curved resin blocks. materials and methods: forty resin blocks with 30º and 45º curvatures (20 blocks for each) were prepared and #30 master cones were placed in canals. in part one, under 20 newton pressure, ni-ti or stainless-...

Cooperative ITS is enabling vehicles to communicate with the infrastructure to provide improvements in traffic control. A promising approach consists in anticipating the road profile and the upcoming dynamic events like traffic lights. This topic has been addressed in the French public project Co-Drive through functions developed by Valeo named Green Light Optimal Speed Advisor (GLOSA). The sys...

We estimate the effect of Internet on volume of trade in a major distributed marketplace. From 1997 to 2007, a period during which residential Internet use tripled, Internet increased the volume of used cars traded in California by 7.2 percent. This implies a substantial welfare gain due to reductions in market frictions of approximately $43 million per year relative to 1997 Internet penetratio...

According to literature, penetration pricing is the dominant pricing strategy for network effect markets. In this paper we show that diffusion of products in a network effect market does not only vary with the set of pricing strategies chosen by competing vendors but also strongly depends on the topological structure of the customers' network. This stresses the inappropriateness of classical "i...

Much of recent Trade theory focuses on heterogeneity of firms and the differential impact trade policy might have on firms with different levels of productivity. A common problem is that most firm level dataset do not contain information on output prices of firms which makes it difficult to distinguish between productivity differences and differences in market power between firms. This paper de...