Extrapolation of Carcinogenicity Between Species: Qualitative and Quantitative Factors

Prediction of human cancer risk from the results of rodent bioassays requires two types of extrapolation: a qualitative extrapolation from short-lived rodent species to long-lived humans, and a quantitative extrapolation from near-toxic doses in the bioassay to low-level human exposures. Experimental evidence on the accuracy of prediction between closely related species tested under similar experimental conditions (rats, mice, and hamsters) indicates that: (1) if a chemical is positive in one species, it will be positive in the second species about 75% of the time; however, since about 50% of test chemicals are positive in each species, by chance alone one would expect a predictive value between species of about 50%. (2) If a chemical induces tumors in a particular target organ in one species, it will induce tumors in the same organ in the second species about 50% of the time. Similar predictive values are obtained in an analysis of prediction from humans to rats or from humans to mice for known human carcinogens. Limitations of bioassay data for use in quantitative extrapolation are discussed, including constraints on both estimates of carcinogenic potency and of the dose-response in experiments with only two doses and a control. Quantitative extrapolation should be based on an understanding of mechanisms of carcinogenesis, particularly mitogenic effects that are present at high and not low doses.     

Videoconferencing: A Viable Teaching Strategy for Social Work Education?

The findings of a study that examined students' reports about their experience with ITV are presented. The results are based on two different courses with different instructors and different composition of students. Results show that students in both sites report that the use of technology does not compromise their learning but they dislike it. Strategies for future research to understand the nature of the reaction are suggested.     

Immigrant Integration Through Mediating Social Institutions: Issues and Strategies

With nearly 40 million foreign-born residents, the United States is the country with the largest immigrant population in the world (Nwosu, Batalova, & Auclair, 2014). This amounts to 13% of the current US population and has fueled debates about the role of immigrants in American society and about what it means to be American (Batalova & Lee, 2012; Hing, 2004). The issue of immigrant integration is at the center of this debate and is also the focus of this study, which examines immigrant integration in two U.S. cities: San Francisco, California and Chicago, Illinois. This study is part of a larger 2007 multi-country study of immigrant integration practices conducted by CeiMigra, a migration research institute based in Valencia, Spain. This study analyzes data collected in the two U.S. study sites, which consists of 19 extensive qualitative interviews with politicians, policy makers, labor leaders, and nongovernment (NGO) and migrant association leaders regarding issues that affect and strategies that facilitate immigrant integration. The interviewees identified two primary points of integration: the economy and local communities. Common barriers affecting both documented and undocumented immigrants were identified, as well as local strategies that promote integration into the economy and the community. Study participants noted the burden on local communities to address immigrant incorporation and called for stronger and more systematic integration programs and policies at the federal level.     

Investing in Leaving: The Greek Case of International Migration of Professionals

In the last twenty years, the ‘international migration of professionals’ from Greece has increased. This paper is based on an extensive survey of Greek professionals who work or have worked in another country. It is the first ever research on the topic in Greece and the first one in the international literature to include participants who are currently abroad or have repatriated. The aim of the paper is threefold. First, it presents the main characteristics of this phenomenon. Second, to explain why Greece, alongside other peripheral countries, suffers from migration of its professionals: in contrast to a dominant view insisting on an allegedly abundant supply of highly skilled labour, it is argued that the phenomenon is primarily due to their low demand in the Greek labour market. Third, to argue that such migration can have positive implications for a country, not only when these people return but also when they stay abroad.