Reassessing Benzene Cancer Risks Using Internal Doses

Human cancer risks from benzene exposure have previously been estimated by regulatory agencies based primarily on epidemiological data, with supporting evidence provided by animal bioassay data. This paper reexamines the animal-based risk assessments for benzene using physiologically-based pharmacokinetic (PBPK) models of benzene metabolism in animals and humans. It demonstrates that internal doses (interpreted as total benzene metabolites formed) from oral gavage experiments in mice are well predicted by a PBPK model developed by Travis et al. Both the data and the model outputs can also be accurately described by the simple nonlinear regression model total metabolites = 76.4x/(80.75 + x), where x = administered dose in mg/kg/day. Thus, PBPK modeling validates the use of such nonlinear regression models, previously used by Bailer and Hoel. An important finding is that refitting the linearized multistage (LMS) model family to internal doses and observed responses changes the maximum-likelihood estimate (MLE) dose-response curve for mice from linear-quadratic to cubic, leading to low-dose risk estimates smaller than in previous risk assessments. This is consistent with the conclusion for mice from the Bailer and Hoel analysis. An innovation in this paper is estimation of internal doses for humans based on a PBPK model (and the regression model approximating it) rather than on interspecies dose conversions. Estimates of human risks at low doses are reduced by the use of internal dose estimates when the estimates are obtained from a PBPK model, in contrast to Bailer and Hoel's findings based on interspecies dose conversion. Sensitivity analyses and comparisons with epidemiological data and risk models suggest that our finding of a nonlinear MLE dose-response curve at low doses is robust to changes in assumptions and more consistent with epidemiological data than earlier risk models.     

Persons and Hypotheses: The Use of the Therapist in the Hypothesising Process

Although hypothesising has been strongly criticised by postmodern and narrative theorists, it plays a major role in any therapy. This article aims to investigate the hypothesising process, first revisiting the concept of hypothesis in semiotics and Schön's theory of the professions, then examining some features of hypothesising within systemic therapy. The article takes into account the relationship between hypotheses and therapists' basic theories, to arrive, finally, at an examination of the role of the person (both therapist and client) in shaping hypotheses within the therapeutic interaction.     

Group Buying of Competing Retailers

Under group buying, quantity discounts are offered based on the buyers' aggregated purchasing quantity, instead of individual quantities. As the price decreases with the total quantity, buyers receive lower prices than they otherwise would be able to obtain individually. Previous studies on group buying focus on the benefit buyers receive in reduced acquisition costs or enhanced bargaining power. In this paper, we show that buyers can instead get hurt from such cooperation. Specifically, we consider a two‐level distribution channel with a single manufacturer and two retailers who compete for end customers. We show that, under linear demand curves, group buying is always preferable for symmetric (i.e., identical) retailers. For asymmetric retailers (i.e., differing in market base and/or efficiency), group buying is beneficial to the smaller (or less efficient) player. However, it can be detrimental to the larger (or more efficient) one. Despite the lower wholesale price under group buying, the manufacturer can receive a higher revenue. Interestingly, group buying is more likely to form when retailers are competitive in different dimensions. These insights are shown to be robust under general nonlinear demand curves, except for constant elastic demand with low demand elasticity.     

Financial contagion through space-time point processes

Statistical Methods & Applications - We propose to study the dynamics of financial contagion by means of a class of point process models employed in the modeling of seismic contagion. The...     

A Note on Two-Way ECM Estimation of SUR Systems on Unbalanced Panel Data

This article considers the two-way error components model (ECM) estimation of seemingly unrelated regressions (SUR) on unbalanced panel by generalized least squares (GLS). As suggested by Biørn (2004 Biørn , E. ( 2004 ). Regression systems for unbalanced panel data: a stepwise maximum likelihood procedure . Journal of Econometrics 122 : 281 – 291 . [Google Scholar]) for the one-way case, in order to use the standard results for the balanced case the individuals are arranged in groups according to the number of times they are observed. Thus, the GLS estimator can be interpreted as a matrix weighted average of the group specific GLS estimators with weights equal to the inverse of their respective covariance matrices.     

Homemaking in the public. On the scales and stakes of framing,feeling, and claiming extra-domestic space as “home”

This article reviews the emerging literature on the negotiation of home-related feelings, claims, and practices in the public urban sphere, under the rubric of homemaking in the public. This contributes to a better sociological understanding of home and illuminates long-debated societal questions such as the interaction between majority and minority groups and the shifting boundaries between what is (regarded as) public or private. While home has traditionally been understood as a private and domestic matter, it also has a major public significance. As a category of analysis, it reveals how supposedly domestic attitudes, routines, and practices are scaled up into the public domain. As a category of practice, it is a powerful discursive resource for contentious politics in the extra-domestic domain. Who is entitled and legitimated to claim a public space as “home”, and what this implies for inter-group categorizations and relations, are questions that deserve original and comparative analysis in sociology. Processes of domestication of the public sphere, of mutual interaction between public and private life realms, and of claims-making on various scales can be fruitfully revisited along these lines, by advancing an original research agenda on the ways of framing, feeling and claiming public space as home.     

A New Proposal to Gauge Intergenerational Mobility: Educational Mobility in Europe as a Case Study

This paper is aimed at presenting a new intergenerational mobility index that (a) combines the intergenerational elasticity and the R-squared of the intergenerational regression and (b) enables the expression of the total degree of mobility as the weighted sum of mobility with respect to both parents. As a case study, we apply our proposal to investigate the intergenerational mobility of education in several European countries and its changes across birth cohorts. The results derived from the proposed index indicate that Nordic countries display higher levels of educational mobility than Southern countries, whereas continental countries are in an intermediate position. Moreover, it appears that the degree of mobility increases over time only in those countries with low initial levels and remains stable for the most mobile countries. Finally, for most of the countries the proposed methodology can prove that the degree of educational mobility with respect to each parent tends to converge to the same level over the course of time.     

Complex Factors and Behaviors in the Gambling Population of Italy

Gambling has seen significant growth globally, and particularly in Italy: it has rapidly evolved from a simple recreational activity to represent 4% of Italian GDP in 2010.A sample of 4.494 gamblers was drawn from IPSAD-Italia^®2007-2008 (Italian Population Survey on Alcohol and Drugs) in order to examine different gambling patterns (assessed using the Canadian Problem Gambling Index Short form scale).Separate analysis was performed on young adults, age 15–24 (n = 1,241; male 56.2%), and adults, age 25–64 (n = 3,253; male 53.8%): compared with adults, Italian youth, although they gambled less (35.7% vs. 45.3%), appeared to have higher prevalence of low risk gambling (6.9% vs. 5.8%) and moderate risk or problem gambling (2.3% vs. 2.2%). Males are more likely to be moderate-risk or problem gamblers. Those with only a primary education are more likely to be moderate-risk or problem gamblers (young adults: RRR = 5.22; adults: RRR = 3.23) than those with a university education, just like those youth who use depressants, but only among younger (RRR = 3.38).A fundamental issue, “do not disapprove of gambling”, seems to relate to problematic gambling: a specific Italian legislation, the Abruzzi Decree Law, could have influenced the perception that gambling may contribute positively to provide additional funds to the government for social good as well as to add needed jobs. Regardless of such potential social benefits, gambling is a social epidemic and if this association should be confirmed by more focused studies, policy makers should evaluate ways to affect this perception as soon as possible.     

Relationship,Social, and Individual Well-Being in Italian Male Same-Sex Couples

This study aimed at investigating Italian male same-sex couples’ attitudes, behaviors, and emotions regarding their own well-being. The study involved included 60 couples, and utilized semistructured interview and subsequent content analysis based on Grounded Theory methods. Findings identified several themes, including recurrent high relationship quality; frequent rejection by members of the family of origin, especially the mother, contrasted by strong support from the “family of choice”; perception of stereotypes and prejudices against same-sex relationships; and feelings of non-acceptance by Italian society, reflected by the lack of sociocultural and legal support and recognition. Despite these difficulties, many of these Italian gay men were able to form durable and satisfying relationships with high levels of well-being.     

Going digital: Using new technologies in visual sociology

Rethinking Visual Anthropology edited by Marcus Banks and Howard Morphy New Haven: Yale University Press, 1997. 310 pages, 90 illustrations. ISNB: 0–300–06691–0 $35.00 cloth

Dancing Naked in the Material World by Marilyn Sudani Futterman. Buffalo: Prometheus Books, 1992. 137 pages. ISBN 0–87975–737‐X paper