The Lamé Class of Lorenz Curves.

In this paper, the class of Lamé Lorenz curves is studied. This family has the advantage of modeling inequality with a single parameter. The family has a double motivation: it can be obtain from an economic model and from simple transformations of classical Lorenz curves. The underlying cumulative distribution functions have a simple closed form, and correspond to the Singh-Maddala and Dagum distributions, which are well known in the economic literature. The Lorenz order is studied and several inequality and polarization measures are obtained, including Gini, Donaldson-Weymark-Kakwani, Pietra and Wolfson indices. Some extensions of the Lamé family are obtained. Fitting and estimation methods under two different data configuration are proposed. Empirical applications with real data are given. Finally, some relationships with other curves are included.The authors thank to Ministerio de Econom a y Competitividad, project ECO2010-15455, for partial support. The second author thanks to the Ministerio de Educaci on (FPU AP-2010-4907) for partial support. We are grateful for the constructive suggestions provided by the reviewers, which improved the paper

Population Support Before and After the Implementation of Smoke-Free Laws in the United States: Trends From 1992-2007

Introduction: Several states implemented comprehensive smoke-free laws in workplaces (14 states), restaurants (17 states), and bars (13 states) between 2002 and 2007. We tested the hypothesis that public support for smoke-free laws increases at a higher rate in states that implemented smoke-free laws between 2002 and 2007 (group A) than in states that implemented smoke-free laws after that time or not at all (group B). The period before the implementation (1992-2001) was also considered. Methods: Data was used from the Current Population Survey (CPS) Tobacco Use Supplements (TUS), which is representative for the U.S. adult population. Respondents were asked whether they thought smoking should not be allowed in indoor work areas, restaurants, and bars and cocktail lounges. Differences in trends were analyzed with binomial mixed effects models. Results: Population support for smoke-free restaurants and bars was higher among group A than among group B before 2002. After 2002, support for smoke-free restaurants and bars increased at a higher rate among group A than among group B. Population support for smoke-free workplaces did not differ between group A and B, and the increase in support for smoke-free workplaces also did not differ between these groups. Conclusions: The positive association between the implementation of smoke-free restaurant and bar laws and the rate of increase in support for these laws partly supported the hypothesis. The implementation of the laws may have caused support to increase, but also states that have higher support may have been more likely to implement smoke-free laws

The effect of surface morphology on the primary fixation strength of uncemented femoral knee prosthesis: a cadaveric study

Item does not contain fulltextWe investigated the effect of surface morphology on the mechanical performance of uncemented femoral knee prosthesis. Eighteen implants were implanted on nine paired femurs and then pushed-off (left legs: a novel surface morphology; right legs: Porocoat as baseline). Bone mineral density (BMD) and anteroposterior dimension were not significantly different between groups. The insertion force was not significantly different, however, the loosening force was significantly higher in the novel group (P=0.007). BMD had a direct relationship with the insertion and loosening force (P<0.001). The effect of surface morphology on implant alignment was very small. We conclude that the surface properties create a higher frictional resistance, thereby providing a better inherent stability of implants featuring the novel surface morphology