Guided Censored Regression

Parametrically guided non‐parametric regression is an appealing method that can reduce the bias of a non‐parametric regression function estimator without increasing the variance. In this paper, we adapt this method to the censored data case using an unbiased transformation of the data and a local linear fit. The asymptotic properties of the proposed estimator are established, and its performance is evaluated via finite sample simulations.     

A hierarchical point process with application to storm cell modelling

In environmetrics, interest often centres around the development of models and methods for making inference on observed point patterns assumed to be generated by latent spatial or spatio‐temporal processes, which may have a hierarchical structure. In this research, motivated by the analysis of spatio‐temporal storm cell data, we generalize the Neyman–Scott parent–child process to account for hierarchical clustering. This is accomplished by allowing the parents to follow a log‐Gaussian Cox process thereby incorporating correlation and facilitating inference at all levels of the hierarchy. This approach is applied to monthly storm cell data from the Bismarck, North Dakota radar station from April through August 2003 and we compare these results to simpler cluster processes to demonstrate the advantages of accounting for both levels of correlation present in these hierarchically clustered point patterns. The Canadian Journal of Statistics 47: 46–64; 2019 © 2019 Statistical Society of Canada     

Straw men and fairy tales: Evaluating reactions to a natural history of rape

In this paper we respond to two frequent criticisms of our book, A Natural History of Rape (Thornhill & Palmer, 2000). The first criticism portrays the book as little more than a “just‐so” story that human rape is an adaptation. We demonstrate that this portrayal is not accurate. The second criticism reflects a common response to the book's challenge of the popular assertion that rapists are not motivated by sexual desire but instead commit these crimes motivated by the urge to power, domination, and violence, and the urge to degrade and humiliate women. We demonstrate that such criticisms of our book are inherently contradictory and illogical. We believe it is important for sex researchers to understand that these sorts of criticisms are seriously flawed so that future research efforts toward understanding the causes of sexual coercion are not stalled.     

Defining Culturally Competent Practice with Sexual Minorities: Implications for Social Work Education and Practice

In recent years, social work has placed an increasing emphasis on culturally competent practice. Although use of that term has referred primarily to practice with ethnic and racial minorities, the concept has been broadened to include social work with other culturally diverse populations. This article examines the application of cultural competence principles to practice with gay, lesbian, bisexual, and transgendered clients. Attitude, knowledge, and skill components are addressed to delineate a culturally competent approach to social work with sexual minorities. Implications for practice, education, and the profession are also discussed.     

Not Such Strange Bedfellows After All

Abstract

The irritable bowel syndrome (IBS) is best defined as abdominal pain of greater than three months duration, with or without a change in bowel habits. Barium studies, sedimentation rate, and the lactose tolerance test are usually within normal limits. The underlying physiology includes a predominance of 3 cycles/minute basal electrical rhythm (BER). The abdominal pain is poorly localized and usually intermittent, without a clear relationship to medication. Differential diagnosis should include inflammatory bowel disease, infectious colitis or gastroenteritis, lactose intolerance, gallbladder disease, peptic ulcer disease, pelvic inflammatory disease, ovarian cysts and tumors, and endometriosis. A sedimentation rate is an important part of the diagnostic workup which may or may not include barium studies. Anticholinergics have been shown to alter the abnormal BER of irritable bowel syndrome and have proven to be of use in treating this syndrome. Dietary counseling should include advising the patient to eat slowly and at regular hours, and heat applied to the abdomen in the form of a hot water bag has been useful. “Overprogrammed” individuals with irritable bowel syndrome should be advised to modify their activities as this type of stress may give rise to the symptoms.

“Effect of Estrogen/Progestin Potency on Lipid/Lipoprotein Cholesterol,” PATRICIA WAHL, CAROLYN WALDEN, ROBERT KNOPP, JOANNE HOOVER, ROBERT WALLACE, GERARDO HEISS, and BASH RIFKIND. We studied 374 women taking oral contraceptives, 284 women taking estrogen preparations after menopause, and 1086 women taking no hormones, to determine the relation of plasma lipids and lipoprotein cholesterol concentrations to various types of estrogen/progestin formulations. Premenopausal women using oral contraceptives containing a relatively low dose of estrogen combined with a medium or high dose of progestin (Norlestrin, Ovral, or Demulen) had a 24 per cent higher median concentration of low-density-lipoprotein cholesterol than did those not using hormones (P < 0.05). Women using oral contraceptives that are high in estrogen and low in progestin (Envoid or Oracon) had significantly higher concentrations of high-density-lipoprotein cholesterol than did nonusers; those using Ovral, a low-estrogen and high-progestin formulation, had significantly lower levels of high-density-lipoprotein cholesterol. In postmenopausal women the use of estrogen was associated with concentrations of low-density-lipoprotein cholesterol that were 11 to 19 per cent below the levels in postmenopausal women who did not use hormones. The effects of estrogen-progestin balance on low-density and high-density lipoproteins may underlie the increased incidence of stroke and myocardial infarction in women of childbearing age who take oral contraceptives. (New England Journal of Medicine 1983;308:862–7.)     

On the Choice of a Prior for Bayesian D-Optimal Designs for the Logistic Regression Model with a Single Predictor

The Bayesian design approach accounts for uncertainty of the parameter values on which optimal design depends, but Bayesian designs themselves depend on the choice of a prior distribution for the parameter values. This article investigates Bayesian D-optimal designs for two-parameter logistic models, using numerical search. We show three things: (1) a prior with large variance leads to a design that remains highly efficient under other priors, (2) uniform and normal priors lead to equally efficient designs, and (3) designs with four or five equidistant equally weighted design points are highly efficient relative to the Bayesian D-optimal designs.     

A neural' network applied to tlie calculation of lyapunov exponents 1

Chaotic deterministics systems are characterised by the instability of orbits on an attractor. The largest Lyapunov exponent measures on average the exponential growth rate of small deviations along an orbit and gives as such an indication whether or not the dynamic generating process is unstable. The direct method for calculation of the Lyapunov exponent, based on finite differences as formulated by the so-called Wolf-algorithm,fails on medium sized data sets. Alternatively, one can use a neural network with backpropagation to estimate a data generating function. This so-calletl indirect method enables us to recover the theoretical value of the largest Lyapunov exponent in several examples.     

Robust linear clustering

Summary.  Non-hierarchical clustering methods are frequently based on the idea of forming groups around 'objects'. The main exponent of this class of methods is the k -means method, where these objects are points. However, clusters in a data set may often be due to certain relationships between the measured variables. For instance, we can find linear structures such as straight lines and planes, around which the observations are grouped in a natural way. These structures are not well represented by points. We present a method that searches for linear groups in the presence of outliers. The method is based on the idea of impartial trimming. We search for the 'best' subsample containing a proportion 1− α of the data and the best k affine subspaces fitting to those non-discarded observations by measuring discrepancies through orthogonal distances. The population version of the sample problem is also considered. We prove the existence of solutions for the sample and population problems together with their consistency. A feasible algorithm for solving the sample problem is described as well. Finally, some examples showing how the method proposed works in practice are provided.