Determination of Leukemogenic Benzene Exposure Concentrations: Refined Analyses of the Pliofilm Cohort

Biologic data on benzene metabolite doses, cytotoxicity, and genotoxicity often show that these effects do not vary directly with cumulative benzene exposure (i.e., concentration times time, or c × t ). To examine the effect of an alternate exposure metric, we analyzed cell-type specific leukemia mortality in Pliofilm workers. The work history of each Pliofilm worker was used to define each worker's maximally exposed job/department combination over time and the associated long-term average concentration associated with the maximally exposed job (LTA-MEJ). Using this measure, in conjunction with four job exposure estimates, we calculated SMRs for groups of workers with increasing LTA-MEJs. The analyses suggest that a critical concentration of benzene exposure must be reached in order for the risk of leukemia or, more specifically, AMML to be expressed. The minimum concentration is between 20 and 60 ppm depending on the exposure estimate and endpoint (all leukemias or AMMLs only). We believe these analyses are a useful adjunct to previous analyses of the Pliofilm data. They suggests that (a) AMML risk is shown only above a critical concentration of benzene exposure, measured as a long-term average and experienced for years, (b) the critical concentration is between 50 and 60 ppm when using a median exposure estimate derived from three previous exposure assessments, and is between 20 and 25 ppm using the lowest exposure estimates, and (c) risks for total leukemia are driven by risks for AMML, suggesting that AMML is the cell type related to benzene exposure.     

Still the Weakest Link: The Domestic Financial System and post‐1998 Recovery in East Asia

To what extent and within what timeframe did countries in East Asia recover from the 1997‐8 financial crisis, and, if there has been a recovery, can it be sustained? Drawing on the available evidence, this article attempts to answer these questions. By implication, however, it also has something to say about the vulnerability of the region to subsequent crises and briefly considers what needs to be done to reduce this.     

AN EXPLORATORY STUDY OF PATTERNS OF PRIORITIES AND TRADE-OFFS AMONG OPERATIONS MANAGERS

A survey of 15 firms showed that agreement among operations managers on competitive priorities is related to agreement on long-run strategic trade-off decisions and not to agreement on shortrun trade-offs. Furthermore, intended short-run actions were often in conflict with stated competitive priorities. Use of management-by-objectives linked to performance appraisal was related to agreement on competitive priorities.     

Gender, household labor, and psychological distress: the impact of the amount and division of housework.

Using a national longitudinal survey of a representative sample of 1,256 adults, I assess the impact of the amount of household labor performed and its division within the household on men's and women's depression levels, adjusting for prior mental health status. I test two alternative explanations of the contributions of household labor and the division of household labor to gender differences in depression: differential exposure and differential vulnerability. The results indicate that men's lower contributions to household labor explain part of the gender difference in depression. Inequity in the division of household labor has a greater impact on distress than does the amount of household labor. Employment status moderates the effect of the division of labor on depression. Among those who describe themselves as keeping house, depression was lowest for those who performed 79.8 percent of housework. In contrast, for those employed full-time the minimum level of depression occurs at 45.8 percent of the household labor. Men report performing 42.3 percent of the housework in their homes compared to 68.1 percent reported by women. Thus, on average women are performing household labor beyond the point of maximum psychological benefit, whereas men are not. Social support mediates the effects of the division of household labor. The only gender difference in effects occurred among those who are married, for whom social support was associated with lower levels of depression for women than men.     

Sexual vs. Nonsexual Currently Most Upsetting Trauma: A Fresh Look at Attenuation of Sexual Response,Alcohol Intoxication,and Post-Traumatic Stress

This study examined the dependence of sexual response (vaginal pulse amplitude [VPA] and subjective sexual arousal) on alcohol intoxication (.10% breath alcohol concentration [BrAC] versus no alcohol) and the nature of a woman’s currently most upsetting traumatic event (C-MUTE), whether it was sexual (e.g., rape) or nonsexual (e.g., combat). Self-reported sexual outcomes were also compared by C-MUTE type. A total of 117 women completed background measures and either drank alcoholic or nonalcoholic beverages. They were shown erotic films and their VPA was assessed. A two (sexual versus nonsexual C-MUTE) by two (.10% BrAC versus no alcohol) analysis of variance (ANOVA) showed that, controlling for post-traumatic stress (PTS) symptoms, women with a sexual C-MUTE showed lower percent VPA change than women with a nonsexual C-MUTE. No significant effects were found for subjective sexual arousal. A multivariate analysis of variance (MANOVA) showed that women with a sexual C-MUTE reported more frequent anxiety and inhibition during partnered sex and more frequent lack of vaginal lubrication versus women with a nonsexual C-MUTE. There was no significant interaction between C-MUTE and alcohol intoxication. Whether a woman is currently upset by past sexual victimization may influence current sexual difficulties. Attenuated VPA may be attributable to the sexual nature of a C-MUTE as opposed to general trauma exposure.     

Dual citizenship or dual identity? Does ‘transnationalism’ supplant ‘nationalism’ among returning Trinidadians?

In this article we focus on the dual identities of relatively young Trinidadians who have decided to return to the island of their birth, or of their parents, while still in their thirties and forties. Highly‐educated professional transnational migrants mostly make up our sample of 36; 26 possess dual citizenship. We focus on our informants’ narratives about their transnational experiences, self‐appraisals of their dual identities and how they value dual citizenship. More generally, we ask, does transnationalism supplant nationalism among our returning informants? Unsurprisingly, the diverse responses we document do not support the commonly held explanatory relationship between return adaptations, ‘national belonging’ and the expected dominance of ‘transnational belonging’. Family relations intervene significantly, both to encourage transnationalism and to strengthen nationalism. Feelings of national belonging often accompany transnationalism. Notably, we view dual citizenship strategically and pragmatically as advantageous to the continuation of transnational practices.     

Bayesian variable selection in logistic regression: predicting company earnings direction

This paper presents a Bayesian technique for the estimation of a logistic regression model including variable selection. As in Ou & Penman (1989), the model is used to predict the direction of company earnings, one year ahead, from a large set of accounting variables from financial statements. To estimate the model, the paper presents a Markov chain Monte Carlo sampling scheme that includes the variable selection technique of Smith & Kohn (1996) and the non-Gaussian estimation method of Mira & Tierney (2001). The technique is applied to data for companies in the United States and Australia. The results obtained compare favourably to the technique used by Ou & Penman (1989) for both regions.     

Meta‐analysis of QTc interval – pooling data from heterogeneous trials

A diverse range of non‐cardiovascular drugs are associated with QT interval prolongation, which may be associated with a potentially fatal ventricular arrhythmia known as torsade de pointes. QT interval has been assessed for two recent submissions at GlaxoSmithKline. Meta‐analyses of ECG data from several clinical pharmacology studies were conducted for the two submissions. A general fixed effects meta‐analysis approach using summaries of the individual studies was used to calculate a pooled estimate and 90% confidence interval for the difference between each active dose and placebo following both single and repeat dosing separately. The meta‐analysis approach described provided a pragmatic solution to pooling complex and varied studies, and is a good way of addressing regulatory questions on QTc prolongation. Copyright © 2002 John Wiley & Sons, Ltd.