Sexual orientation as destiny

The article argues that social constructionists are referring to labels applied to sexual orientation while essentialists are discussing sexual orientation itself. Although a review of the literature shows that various labels are applied to sexual orientation, these labels do not markedly affect its reality. Sexual orientation, defined as erotic attraction rather than sexual behavior, is established at an early age and largely immutable in adulthood.     

Multivariate extreme-value distributions with applications to environmental data

Some parametric families of multivariate extreme-value distributions have been proposed in recent years; several additional parametric families are derived here. The parametric models are fitted, using numerical maximum likelihood, to some environmental multivariate extreme data sets consisting of extreme concentrations of a pollutant at several monitoring stations in a region. Some multivariate nonnormal data analysis techniques are proposed to aid in the likelihood analysis. The new models, together with previous models, appear to be adequate for inferences in that they cover a wide range of possible dependence patterns.     

Numerical optimization and surface estimation with imprecise function evaluations

This paper presents an investigation of a method for minimizing functions of several parameters where the function need not be computed precisely. Motivated by problems requiring the optimization of negative log-likelihoods, we also want to estimate the (inverse) Hessian at the point of minimum. The imprecision of the function values impedes the application of conventional optimization methods, and the goal of Hessian estimation adds a lot to the difficulty of developing an algorithm. The present class of methods is based on statistical approximation of the functional surface by a quadratic model, so is similar in motivation to many conventional techniques. The present work attempts to classify both problems and algorithmic tools in an effort to prescribe suitable techniques in a variety of situations. The codes are available from the authors' web site http://macnash.admin.uottawa.ca/~rsmin/.