The dynamics of HIV spread: a computer simulation model

Mathematical modeling of the AIDS pandemic has been limited by the difficulty of satisfactorily representing the marked behavioral heterogeneity that characterizes the various populations at risk. We propose an approach which models the spread of infection as a discrete-event simulation using SIMSCRIPT, a powerful simulation language. The program developed provides sufficient flexibility to adequately represent and study a wide range of risk-group dynamics. Using this tool we have verified the May-Anderson prediction relating contact rate heterogeneity to the rate of HIV spread. We have also been able to assess the sensitivity of the model to the particular choice of distribution for contact rates, disease stage durations, and intercontact intervals. It is thought that this approach will permit the empirical testing of hypotheses which do not lend themselves to a purely mathematical treatment.     

Overlapping with Jack Dunitz

The starting point was an overlap with Jack Dunitz in studies on the preferred conformation of the carboxyl group in saturated and unsaturated acids, esters and amides, orientational disorder of the hydrogen-bonded carboxylic acid dimer in benzoic acid crystal structures, and intramolecular lone pair-lone pair repulsion between oxygen atoms. The journey described here outlines a search to establish the existence of C−H⋅⋅⋅O hydrogen bonds and engineering cocrystals that incorporate intermolecular lone pair-lone pair repulsion between oxygen atoms.     

Lichens as litmus for air pollution: a historical review

The literature on the relationships between lichens and air pollution is reviewed, with particular reference to the development of the concepts governing their use as indicators of air pollution levels. Lichens are particularly sensitive to sulphur dioxide which acts by the destruction of chlorophyll. By considering both the species present and their abundance, zones indicative of mean air pollution levels can be quickly mapped. The way in which some species respond in different regions varies and so zonal scales can only be reliably applied in the areas where they were devized. Only in a few cases has it been possible to correlate lichen zones with particular sulphur dioxide concentrations, principally because of a lack of physicochemical measurements; but even where such correlations are not possible, lichen zones provide a rapid qualitative means of assessing the effects of air pollution. Maps showing the type of data obtained by this method are presented, and a table summarizes the published work on major cities, towns, industrial plants, and in larger geographical regions.     

Comparison of the pulsed field gel electrophoresis patterns and virulence profiles of the multidrug resistant strains of Salmonella enterica serovar Schwarzengrund isolated from chicken meat and humans in Taiwan

Salmonella Schwarzengrund is one of the frequent serovars isolated from chicken meat in Taiwan. This organism is also one of the invasive Salmonella serovars which may cause human salmonellosis and animal infections. In this study, a total of 466 strains of S. Schwarzengrund including 232 retail chicken meat isolates and 234 human isolates in Taiwan were analyzed for their antibiotic resistance and pulsed field gel electrophoresis (PFGE) patterns. For XbaI-digested DNA, a total of 110 PFGE patterns were obtained. When patterns from both origins were analyzed, of these patterns, 21 were shared by isolates from chicken meat samples and humans. In these 21 patterns, 153 (32.8%) isolates from both origins shared the top five patterns. Since ACSSXTT R-type strains are the major concern worldwide and they accounted for 74.5% of total strains used in this study, such R-type strains in the top five XbaI-digested patterns were then further analyzed with AvrII digestion followed by PFGE and PCR assay targeted to 10 Salmonella virulence genes, i.e., avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC. When PFGE patterns and virulence gene profiles were combined for the analysis of ACSSXTT R-type strains of S. Schwarzengrund, 29 strains from both origins showed the same pattern combinations. Such results suggested the possible transmission of S. Schwarzengrund from chicken meat to humans.     

A graphical representation for a statistical test of average equivalence and variance comparison with process data

This paper provides a graphical approach for presenting results of a statistical test of average equivalence with process data. In addition, a graphical representation of process change in variance is presented. An example from the biopharmaceutical industry is provided to illustrate the information contained in the chart. Copyright © 2010 John Wiley & Sons, Ltd.     

Optimal levels of emotional arousal in experiential therapy of depression.

Objective: To determine the relationship between length of time spent expressing highly aroused emotion and therapeutic outcome. Method: Thirty-eight clients (14 male, 24 female) between the ages of 22 and 60 years (M = 39.5, SD = 9.71), treated for depression with experiential therapy, were rated on working alliance and expressed emotional arousal (with the Client Expressed Emotional Arousal Scale) in their three highest arousal sessions. Among the clients, 34 were of European ethnicity, 2 were of Asian ethnicity, 1 was of Latino ethnicity, and 1 was of Caribbean–Canadian ethnicity. Clients were administered the short form of the Working Alliance Inventory following their 4th therapy session and also completed, pre- and posttherapy, the Beck Depression Inventory (BDI), the Global Severity Index (GSI) of the Symptom Checklist–90–Revised (SCL-90-R), the Inventory of Interpersonal Problems, and the Rosenberg Self-Esteem Scale. Results: Hierarchical regressions showed that a nonlinear pattern of expressed emotional arousal predicted outcome significantly above the alliance. This combination predicted 30% of outcome variance on the BDI and 24% on the GSI (p