A simulated annealing methodology for clusterwise linear regression

In many regression applications, users are often faced with difficulties due to nonlinear relationships, heterogeneous subjects, or time series which are best represented by splines. In such applications, two or more regression functions are often necessary to best summarize the underlying structure of the data. Unfortunately, in most cases, it is not known a priori which subset of observations should be approximated with which specific regression function. This paper presents a methodology which simultaneously clusters observations into a preset number of groups and estimates the corresponding regression functions' coefficients, all to optimize a common objective function. We describe the problem and discuss related procedures. A new simulated annealing-based methodology is described as well as program options to accommodate overlapping or nonoverlapping clustering, replications per subject, univariate or multivariate dependent variables, and constraints imposed on cluster membership. Extensive Monte Carlo analyses are reported which investigate the overall performance of the methodology. A consumer psychology application is provided concerning a conjoint analysis investigation of consumer satisfaction determinants. Finally, other applications and extensions of the methodology are discussed.     

Eric J. Sharpe (1933–2000)

This paper gives a general account of the developments in the Baha'i Faith over the last three decades. The period began with the Baha'i Faith as a little-known religion with a hereditary leadership of predominantly Iranian membership but with some spread to the West. At the present time the religion has been transformed into a much better-known religion led by an elected council. It has increased some 20-fold in numbers and is now world-wide in membership. The major structural changes involved as the previous hereditary leadership at the international level was converted into the leadership of an elected council are analysed. The growth and development of the religion over this period are described and some statistical information is given. The central concerns of the religion during this time are described in terms of a number of motifs: polar, legalism, millenarianism, social reformism, universalism, liberalism, and martyrdom and sacrifice. An attempt is made to analyse some of the present problems facing the Baha'i community, both in terms of the persecutions that it suffers as well as the problems presented by its successful expansion, and to describe the ways in which it copes with these.     

Mending the Broken Frame: Self-Narration in a Constructionist Framework

The communal construction of mental illness makes recovery a daunting challenge since society largely perceives the psychiatrically ill as ??deficient??. Not only does one have to deal with the illness itself, one additionally has to deal with the perpetual stigma associated with the labeling, increasing the personal consequences of these illnesses. In my own journey through mental illness, I have repeatedly tried to construct for myself those structures which would help me become stable and empower me from within rather than rob me of my sense of self. This paper is a small expression of that narrative.     

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice

Memory consolidation is defined temporally based on pharmacological interventions such as inhibitors of mRNA translation (molecular consolidation) or post-acquisition deactivation of specific brain regions (systems level consolidation). However, the relationship between molecular and systems consolidation are poorly understood. Molecular consolidation mechanisms involved in translation initiation and elongation have previously been studied in the cortex using taste-learning paradigms. For example, the levels of phosphorylation of eukaryotic elongation factor 2 (eEF2) were found to be correlated with taste learning in the gustatory cortex (GC), minutes following learning. In order to isolate the role of the eEF2 phosphorylation state at Thr-56 in both molecular and system consolidation, we analyzed cortical-dependent taste learning in eEF2K (the only known kinase for eEF2) ki mice, which exhibit reduced levels of eEF2 phosphorylation but normal levels of eEF2 and eEF2K. These mice exhibit clear attenuation of cortical-dependent associative, but not of incidental, taste learning. In order to gain a better understanding of the underlying mechanisms, we compared brain activity as measured by MEMRI (manganese-enhanced magnetic resonance imaging) between eEF2K ki mice and WT mice during conditioned taste aversion (CTA) learning and observed clear differences between the two but saw no differences under basal conditions. Our results demonstrate that adequate levels of phosphorylation of eEF2 are essential for cortical-dependent associative learning and suggest that malfunction of memory processing at the systems level underlies this associative memory impairment.     

Examining the Factor Structure of the Revised Sense of Purpose Scale (SOPS-2) with Adults

Based on the multidimensional conceptualization of purpose, the sense of purpose scale is designed to measure three distinct constructs: awareness of purpose, altruistic purpose, and awakening to purpose. Building on previous work, the present study examined the factor structure, reliability, and validity of the revised sense of purpose scale (SOPS-2) and examined its associations with wellbeing among adults in three independent studies (N = 1209). Confirmatory factor analysis was used to examine the factor structure and tests of measurement invariance were conducted across occupation (adult students and university employees) and gender (males and females). Positive correlations between sense of purpose and a number of constructs of socio-emotional wellbeing were found: positivity, humility, self-esteem, and moral identity (Study 2) and pride, compassion self-esteem, and life regret (Study 3). Taken together, findings suggest that the SOPS-2 can be used as a measure of sense of purpose in life in adults.