A counterexample to a claim concerning the convolution of multimodal distributions

P. Ghosh (1981) has claimed that the convolution of two symmetric multimodal distributions is symmetric and unimodal. A simple counterexample to this claim is constructed by considering the convolution f?f, where f is an appropriate mixture of two normal densities.

     

An exploratory study of the influence of the IS function and organizational context on business process reengineering project initiatives

To help evaluate the risk of process reengineering failure and enhance the prospect of its success, three potential sources of influence on BPR initiatives and success are examined in this study. These include the innovative capacity of the organization, IS maturity and strategy-IS interface. It was found that while factors related to IT maturity and influence such as experience in mainframe and client/server computing may facilitate the decision to reengineer, they are not critical in the later stages of the initiative. On the other hand, factors having significant relationships beyond the initial decision include variables pertaining to innovative capacity of the organization and strategy-IS interface. These findings suggest that technical IT competence as a critical enabler is necessary but not sufficient for reengineering success. Based on study findings regarding the innovative capacity of the organization, guidelines for reengineering risk assessment are proposed. In addition, implications of the findings, limitations of the study and opportunities for further research are also discussed.     

Density Estimation in Several Populations With Uncertain Population Membership

We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.     

Technology and Obsessive Compulsive Disorder: An Interactive Self-Help Website for OCD

Obsessive Compulsive Disorder (OCD) is a neurobiological illness characterized by unwanted thoughts and/or images followed by repetitive rituals. About 5 million Americans live with Obsessive Compulsive Disorder. OCD is a manageable illness when proper interventions are utilized. Treatment for OCD is limited due to the lack of adequately trained professionals and the high costs of treatment. Cognitive behavioral therapy (CBT) in conjunction with exposure with response prevention (ERP) is the most effective intervention modality available for OCD. To address the treatment gap, an online, interactive self-help website was developed for those living with OCD without access to an effective intervention. This report will explore development of the OCD Challenge website and future implications of its use.     

Pornography Actresses: An Assessment of the Damaged Goods Hypothesis

The damaged goods hypothesis posits that female performers in the adult entertainment industry have higher rates of childhood sexual abuse (CSA), psychological problems, and drug use compared to the typical woman. The present study compared the self-reports of 177 porn actresses to a sample of women matched on age, ethnicity, and marital status. Comparisons were conducted on sexual behaviors and attitudes, self-esteem, quality of life, and drug use. Porn actresses were more likely to identify as bisexual, first had sex at an earlier age, had more sexual partners, were more concerned about contracting a sexually transmitted disease (STD), and enjoyed sex more than the matched sample, although there were no differences in incidence of CSA. In terms of psychological characteristics, porn actresses had higher levels of self-esteem, positive feelings, social support, sexual satisfaction, and spirituality compared to the matched group. Last, female performers were more likely to have ever used 10 different types of drugs compared to the comparison group. A discriminant function analysis was able to correctly classify 83% of the participants concerning whether they were a porn actress or member of the matched sample. These findings did not provide support for the damaged goods hypothesis.     

Creating “Community”? Preparing for Bushfire in Rural Victoria

The term “community” has a long and contested lineage in social analysis and debate. This lineage, however, is not generally recognized in policy and public debates on community and bushfire in Australia. “Community” is thought to be central to bushfire preparedness in Australia, especially in rural areas, but what “community” actually means in this context is vague at best. There is an ever‐present tension between the use of “community” as a reference to locality, a “sense of community” as experienced by residents, and the use of “community” as a rhetorical tool by governments and state agencies. We argue that a rigorous analysis of the concept of “community” is critical to an understanding of the processes involved in preparing for the challenges associated with disaster, in this case bushfires. These broader issues are supported by research (a series of surveys, interviews, and focus groups) carried out with residents living in (predominantly rural) bushfire‐prone areas in the state of Victoria, Australia. Ultimately, we assert that social participation and social networks are likely to be the crucial aspects of community that play a central role in effective bushfire preparedness.     

Parenting During Childhood Predicts Relationship Satisfaction in Young Adulthood: A Prospective Longitudinal Perspective

Using three waves of data drawn from the National Survey of Families and Households (n = 438 young adult children) we examined the process by which parental warmth and harsh parenting during childhood influences children's romantic relationship satisfaction in young adulthood. Harsh parenting was directly associated with children's relationship satisfaction, independently and in conjunction with parental warmth, whereas parental warmth was indirectly associated with relationship satisfaction through family cohesion during adolescence. Results were consistent across male and female young adults involved in married, dating, and cohabiting relationships. Findings from this prospective, longitudinal study coincide with previous research using adult children's retrospective reports of parenting behavior and highlight the importance of family of origin influences on romantic relationships in young adulthood.     

Exploring bystander presence and intervention in nonfatal violent victimization: when does helping really help?

The current research explores two important issues related to the study of bystander intervention during nonfatal violent victimization. First, using data from the National Crime Victimization Survey (NCVS), conjunctive analysis of case configurations is conducted to identify the most dominant situational contexts in which a bystander is present during violent crime. Second, the prevalence of responses in which a bystander helps or hurts during these events is determined. Results and the analytical approach used in this investigation are discussed in terms of their implications for future research on the normative and deviant reactions to crime by third parties and its victims.     

A grouped beta process model for multivariate resting‐state EEG microstate analysis on twins

EEG microstate analysis investigates the collection of distinct temporal blocks that characterize the electrical activity of the brain. Brain activity within each microstate is stable, but activity switches rapidly between different microstates in a nonrandom way. We propose a Bayesian nonparametric model that concurrently estimates the number of microstates and their underlying behaviour. We use a Markov switching vector autoregressive (VAR) framework, where a hidden Markov model (HMM) controls the nonrandom state switching dynamics of the EEG activity and a VAR model defines the behaviour of all time points within a given state. We analyze the resting‐state EEG data from twin pairs collected through the Minnesota Twin Family Study, consisting of 70 epochs per participant, where each epoch corresponds to 2 s of EEG data. We fit our model at the twin pair level, sharing information within epochs from the same participant and within epochs from the same twin pair. We capture within twin‐pair similarity, using an Indian buffet process, to consider an infinite library of microstates, allowing each participant to select a finite number of states from this library. The state spaces of highly similar twins may completely overlap while dissimilar twins could select distinct state spaces. In this way, our Bayesian nonparametric model defines a sparse set of states that describe the EEG data. All epochs from a single participant use the same set of states and are assumed to adhere to the same state switching dynamics in the HMM model, enforcing within‐participant similarity.