This study uses the National Educational Longitudinal Survey of 1988 (NELS) to replicate both the analysis in The Bell Curve and that of several of its previous replications. We examine the relative importance of test scores and family background in predicting dropping out of high school, starting college, arrests, and out-of-wedlock fertility. Our results relax several arbitrary assumptions ma...

In this study, we introduce a new type of surface curves called $D$-type curve. This curve is defined by the property that the unit Darboux vector $vec{W}_{0} $ of a surface curve $vec{r}(s)$ and unit surface normal $vec{n} $ along the curve $vec{r}(s)$ satisfy the condition $leftlangle vec{n} ,vec{W}_{0} rightrangle =text{constant}$. We point out that a $D$-type curve is a geodesic curve or an...

We prove that every algebraic curve X/Q is birational over C to a Teichmüller curve. keywords: algebraic curve, mapping class group, Teichmüller curve, Veech group. MSC code: 32G15, 37D40.