Characterizing Dose-Response Relationships in Multiple Cancer Bioassays

In the evaluation of chemical compounds for carcinogenic risk, regulatory agencies such as the U.S. Environmental Protection Agency and National Toxicology Program (NTP) have traditionally fit a dose-response model to data from rodent bioassays, and then used the fitted model to estimate a Virtually Safe Dose or the dose corresponding to a very small increase (usually 10(-6)) in risk over background. Much recent interest has been directed at incorporating additional scientific information regarding the properties of the specific chemical under investigation into the risk assessment process, including biological mechanisms of cancer induction, metabolic pathways, and chemical structure and activity. Despite the fact that regulatory agencies are currently poised to allow use of nonlinear dose-response models based on the concept of an underlying threshold for nongenotoxic chemicals, there have been few attempts to investigate the overall relationship between the shape of dose-response curves and mutagenicity. Using data from an historical database of NTP cancer bioassays, the authors conducted a repeated-measures Analysis of the estimated shape from fitting extended Weibull dose-response curves. It was concluded that genotoxic chemicals have dose-response curves that are closer to linear than those for nongenotoxic chemicals, though on average, both types of compounds have dose-response curves that are convex and the effect of genotoxicity is small.     

CAN A HIGH SENSE OF CONTROL AND JOHN HENRYISM BE BAD FOR MENTAL HEALTH?

Social stratification profoundly affects mental health. Specifically, substantial empirical evidence finds that higher status promotes mental health via a higher sense of control and a propensity to cope actively with problems. An unresolved issue, though, is whether the effects of sense of control and active coping on mental health are uniformly beneficial across levels of socioeconomic status. Perceived control and John Henryism, an active coping style, may undermine mental health, especially for lower-status persons, who lack resources. Using data from the National Comorbidity Survey for African Americans, Hispanics, and whites, we find that both sense of control and John Henryism tend to be monotonically related to positive mental health regardless of socioeconomic status and race/ethnicity.     

Voices from Segregated Schooling: towards an inclusive education system

Romantown LEA, like other authorities in England and Wales, is adopting a policy of 'inclusion' in providing education for young disabled people. The reorganisation has involved the closure of Adamston, an all-age school for pupils with physical disabilities. This article addresses the meaning of 'inclusion' from the viewpoint of disabled people who have experienced segregated education. We draw first on the literature to offer an analysis of the documented views of survivors of special schools. Secondly, we explore the views and experiences of Adamston pupils prior to the closure of the school. In presenting what clearly represents a wide range of experiences we seek to take the debate beyond the sterile analysis of 'pros and cons' of special schools. We argue that voices from experiences of segregation are central in constructing 'inclusion' and essential in any process of change towards an education system which is truly inclusive.     

Popularity and Social Preference in Chinese Adolescents: Associations with Social and Behavioral Adjustment

This study examined the characteristics associated with popularity and social preference in 769 14‐year‐old adolescents (54 percent boys) from mainland China. Consistent with findings from other countries, popularity and social preference were moderately correlated and overt aggression was positively correlated with popularity but negatively correlated with social preference. Prosocial behavior, athletic skill, dating, academic achievement, and mutual friends were positively associated with both popularity and social preference, with the effects for prosocial behavior, athletic skill, and dating greater for popularity than for social preference. The strong correlations between popularity and prosocial behavior are consistent with Confucian ideas of moral leadership and the obligations of high status individuals toward others. Cultural values are also reflected in the association of popularity with academic achievement. The inconsistent findings from China regarding the relation between aggression and popularity may stem from multiple factors including the absence of a suitable Chinese translation for popularity.     

Stochastic Estimates of Exposure and Cancer Risk from Carbon Tetrachloride Released to the Air from the Rocky Flats Plant

Carbon tetrachloride is a degreasing agent that was used at the Rocky Flats Plant (RFP) in Colorado to clean product components and equipment. The chemical is considered a volatile organic compound and a probable human carcinogen. During the time the plant operated (1953-1989), most of the carbon tetrachloride was released to the atmosphere through building exhaust ducts. A smaller amount was released to the air via evaporation from open-air burn pits and ground-surface discharge points. Airborne releases from the plant were conservatively estimated to be equivalent to the amount of carbon tetrachloride consumed annually by the plant, which was estimated to be between 3.6 and 180 Mg per year. This assumption was supported by calculations that showed that most of the carbon tetrachloride discharged to the ground surface would subsequently be released to the atmosphere. Atmospheric transport of carbon tetrachloride from the plant to the surrounding community was estimated using a Gaussian Puff dispersion model (RATCHET). Time-integrated concentrations were estimated for nine hypothetical but realistic exposure scenarios that considered variation in lifestyle, location, age, and gender. Uncertainty distributions were developed for cancer slope factors and atmospheric dispersion factors. These uncertainties were propagated through to the final risk estimate using Monte Carlo techniques. The geometric mean risk estimates varied from 5.2 x 10(-6) for a hypothetical rancher or laborer working near the RFP to 3.4 x 10(-9) for an infant scenario. The distribution of incremental lifetime cancer incidence risk for the hypothetical rancher was between 1.3 x 10(-6) (5% value) and 2.1 x 10(-5) (95% value). These estimates are similar to or exceed estimated cancer risks posed by releases of radionuclides from the site.     

Approaches to Equity Management and their Relationship to Women in Management

Developing equitable practices that provide fair access for all individuals to the benefits and burdens within an organization remains a dilemma for management both in policy and in practice. Research continues to show that the employment status and representation for members of some groups is significantly less than in relation to those of other groups. Addressing the issue of disparity has resulted in a number of different approaches. The main aim of this paper is to explore the ability of a typological theory of equal employment opportunity implementation to account for the differences in the numbers of women in management and in management tiers. This paper identifies and analyses four ideal-typical equity management approaches to achieving workplace parity: traditional (non-compliance), anti-discrimination, affirmative action and equal employment opportunity. While the objective of these approaches may be to ensure equity management in order to encourage equal outcomes the results tell a different story. Results show that an affirmative action approach to equity management predicts increases in women in management across all tiers of management.     

Cannabis Use and Antisocial Behavior among Youth

Despite the numerous efforts to curb substance use and abuse through legislation and interventions, marijuana consumption continues to be a major social problem, particularly among young adults in the United States. We provide new information on the relationship between cannabis use and antisocial behavior by analyzing a sample of young adults (aged 18–20) from the National Epidemiological Survey of Alcohol and Related Conditions (NESARC). We examine a broad set of cannabis use patterns and multiple dimensions of antisocial behaviors and test the empirical importance of two prominent criminological theories—general strain and social bond—in explaining associations between cannabis use and antisocial behavior. We include important socioeconomic, demographic, health and health behaviors, and contextual information in all regressions to control for confounding factors. Our results imply that cannabis use is positively and significantly related to antisocial behavior among young adults, and general strain and social bond theories cannot fully explain our findings. As expected, the estimated association with antisocial behavior is stronger for more frequent cannabis users.     

Prosecuting Pay Equity: Evolving Strategies in Britain and Australia

Some thirty years after the introduction of pay equity provisions in Australia and Britain, continued encroachments on the gender pay gap seem inordinately difficult to deliver. This article provides some reflection on the prosecution of pay equity cases in the two countries over this period, and seeks to identify lessons that can be drawn by contrasting the different approaches that have evolved. We are concerned in particular with the impact of decentralizing trends, and the potential to develop strategies that can operate effectively in these circumstances. We show that while Britain began with relatively narrow provisions, these have gradually been extended through case law. However, job evaluation processes have proved tortuous and time‐consuming, and the main successes have been in the more regulated sectors of the economy, particularly the public sector. In contrast, while Australia has enjoyed significant advantages associated with its more centralized industrial relations framework, this has not been without costs, and Australia has little of the case experience acquired in Britain to rely on as the benefits of centralization are eroded.     

Self–organization and trade union democracy

This article is an offshoot of a three year study into the self–organized groups for women, black members, disabled members and lesbians and gay men which have been enshrined in the constitution of the UK’s public sector union UNISON. The argument is that self–organization has become a significant axis around which trade union democracy is being reconstituted in the late twentieth century. However, our understanding of this phenomenon has been obscured by the ascendancy of mainstream union perspectives over self–organized perspectives, which has unfortunately been compounded by academic researchers. A re–conceptualization of self–organization proceeds in three stages. First, it is contextualized politically and theoretically in terms of trade union histories, new social movements and models of a diversified democratic polity. Second, it is re–signified by attending to its actual unfolding over the past two decades and the self–understandings of its activists. Third, is problematized with reference to exogenous pressures towards bureaucracy and oligarchy, and endogenous pressures towards essentialisms and exclusions.     

Research Review: In a rush to permanency: preventing adoption disruption

Since the late 1990s, US, UK and Canadian policy have increasingly focused on improving permanency outcomes for looked‐after children. Although the ideal permanency outcome of reunification is attained for about half of the children entering out‐of‐home care, an increasing number of children are adopted each year. The vast majority of adoptions are stable and secure, but concerns about adoption disruption haunt child welfare workers when making this important permanency decision. Despite a variety of definitions employed in the literature, adoption disruption is a general term used to describe the failure or breakdown of an adoptive child’s placement. Studies dating back to the 1970s have reported adoption disruption rates and the characteristics associated with those involved in such cases. This paper reviews available research, principally from the United States, and offers possible explanations for the wide range of reported disruption rates in the literature. After reviewing the research, practice implications for improving adoption outcomes and suggestions for future research are presented.