Maximum entropy sampling and optimal Bayesian experimental design

When Shannon entropy is used as a criterion in the optimal design of experiments, advantage can be taken of the classical identity representing the joint entropy of parameters and observations as the sum of the marginal entropy of the observations and the preposterior conditional entropy of the parameters. Following previous work in which this idea was used in spatial sampling, the method is applied to standard parameterized Bayesian optimal experimental design. Under suitable conditions, which include non-linear as well as linear regression models, it is shown in a few steps that maximizing the marginal entropy of the sample is equivalent to minimizing the preposterior entropy, the usual Bayesian criterion, thus avoiding the use of conditional distributions. It is shown using this marginal formulation that under normality assumptions every standard model which has a two-point prior distribution on the parameters gives an optimal design supported on a single point. Other results include a new asymptotic formula which applies as the error variance is large and bounds on support size.     

Expert Study to Select Indicators of the Occurrence of Emerging Mycotoxin Hazards

This article describes a Delphi‐based expert judgment study aimed at the selection of indicators to identify the occurrence of emerging mycotoxin hazards related to Fusarium spp. in wheat supply chains. A panel of 29 experts from 12 European countries followed a holistic approach to evaluate the most important indicators for different chain stages (growth, transport and storage, and processing) and their relative importance. After three e‐mailing rounds, the experts reached consensus on the most important indicators for each of the three stages: wheat growth, transport and storage, and processing. For wheat growth, these indicators include: relative humidity/rainfall, crop rotation, temperature, tillage practice, water activity of the kernels, and crop variety/cultivar. For the transport and storage stage, they include water activity in the kernels, relative humidity, ventilation, temperature, storage capacity, and logistics. For wheat processing, indicators include quality data, fraction of the cereal used, water activity in the kernels, quality management and traceability systems, and carryover of contamination. The indicators selected in this study can be used in an identification system for the occurrence of emerging mycotoxin hazards in wheat supply chains. Such a system can be used by risk managers within governmental (related) organizations and/or the food and feed industry in order to react proactively to the occurrence of these emerging mycotoxins.     

The Psychodynamics of Consensual Sadomasochistic and Dominant-Submissive Sexual Games

The author examines a case from a qualitative research study exploring repetition-compulsion and repair in consensual sadomasochistic/dominant-submissive (SMDS) sexual play. The study attempts to bridge the epistemological divide between clinically derived psychoanalytic theories about perversion and nonclinical research on consensual SMDS subcultures. The case addresses research questions about the presence of, and possibilities for, working through childhood developmental conflicts in consensual SMDS (as theoretically differentiated from its nonconsensual counterparts).

This study, along with those theories that uproot classical notions of sexuality and the “oedipal divide,” lends support for the view that the diversity of lived and practiced sexualities defies facile categorization and that, if categorization is to be attempted, it must take into account individual meanings and relational/larger social contexts.     

Living Behind Dikes: Mimicking Flooding Experiences

Delta areas like the Netherlands are threatened by global climate change. Awareness is, however, rather low. Our research objective was to investigate whether coping responses to flooding risks could be enhanced in a virtual environment (VE). A laboratory experiment was conducted in which participants were exposed to a simulated dike breach and consequent flooding of their virtual residence. We tested the hypothesis that an interactive 3D flood simulation facilitates coping responses compared to noninteractive film and slide simulations. Our results showed that information search, the motivation to evacuate, and the motivation to buy flood insurance increased after exposure to the 3D flood simulation compared to the film and slide simulations. Mediation analyses revealed that some of these presentation mode effects were mediated by a greater sense of being present in the VE. Implications to use high‐end flood simulations in a VE to communicate real‐world flooding risks and coping responses to threatened residents will be discussed.     

The mad estimator: when is it non-linear? applications to two-way design models

The mean absolute deviation (MAD) estimator has recently received a great deal of attention as applied to full-rank linear regression models. This paper provides a necessary and sufficient condition for the MAD estimator to be a non-linear estimator, in which case conditions for the variance of the MAD estimator to be larger or smaller than those for OLS are, in general, unknown. The non-linearity of the MAD estimator is examined for several two-way designs; in particular (1) randomized block design (2) two-way nested design (3) two-way classification with interaction and (4) partially balanced incomplete block design     

Entwickeln im Team – Effekte für den Einzelnen

This study tested the effects of a 2-day team building intervention on team members’ team identification, social support and collective self-efficacy. Members (n?=?32) of three teams from different sectors completed questionnaires before, directly after and six weeks after the team building intervention. Two teams served as control groups. Results showed lasting positive effects of team building on identification, support and collective self-efficacy in the training groups but no changes in the control groups.     

A Preliminary Investigation of a Telephone Administration of the Quality of Marriage Index

Follow‐up data collection presents many challenges for longitudinal research. Validating paper‐and‐pencil assessments for use via telephone may alleviate these issues. This study evaluates psychometric properties of the Quality of Marriage Index (QMI; Norton, 1983, Journal of Marriage and the Family, 45, 141) when administered by telephone and compares scores with the paper‐and‐pencil version. Participants included women with major depressive disorder and dyadic discord and their male spouses (n = 24 couples). Results suggest excellent scale reliability for the verbal QMI. However, a significant mean difference was found: participants scored on average 3 points higher on the telephone‐administered QMI than on the written QMI. Recommendations for future research and clinical implications are discussed.     

College Student Behavior: A Ten-Year Look

Abstract

Lester and Perez¹ have suggested that student behavior can be usefully construed in terms of a traditional-hedonic, implicit value system. They demonstrated that drug use and sexual activity provide simple behavioral anchors for this dimension, and observed an increasingly hedonic orientation among students. Ten years after their initial study, the student population at the same institution was again sampled using an anonymous questionnaire. The 1980 sample included 208 subjects, and these were compared with 688 subjects who responded to the 1970 survey. This comparison was supplemented by an intensive week-long study of 53 students within one campus living unit.

Significant increases in pre-college sexual activity were noted for both men and women. Marijuana use in high school also increased for both men and women during this period, while alcohol use increased only among women. Previously observed differences between male and female pre-college sexual activity and marijuana use had largely disappeared by 1980. Significant increases in sexual activity while in college were found for women but not for men. For men, overall marijuana and alcohol use in college did not change during the study period, but there was an increase in the frequent use of these drugs. Increases in all categories of marijuana use were noted among women, along with overall increases in their alcohol use. The significant differences between male and female marijuana use noted in the 1970 study were absent in 1980. The intensive week-long study revealed that alcohol use was part of the daily lives of one-third to two-thirds of the students sampled, although they reported interpersonal conflicts, absences from class, accidents, and injuries among the consequences of their drinking. A significant inverse relationship between sleep and alcohol use was observed among women, but not among men.

These data suggest that student behavior has become increasingly hedonic during the past ten years, with women in particular closing the gap which previously differentiated their behavior from that of their male peers. Institutions of higher learning must take these changes into account in the planning of academic programs, residential life, and health services.