Development of a Unit Risk Factor for 1,3-Butadiene Based on an Updated Carcinogenic Toxicity Assessment

The Texas Commission on Environmental Quality (TCEQ) has developed an inhalation unit risk factor (URF) for 1,3-butadiene based on leukemia mortality in an updated epidemiological study on styrene-butadiene rubber production workers conducted by researchers at the University of Alabama at Birmingham. Exposure estimates were updated and an exposure estimate validation study as well as dose-response modeling were conducted by these researchers. This information was not available to the U.S. Environmental Protection Agency when it prepared its health assessment of 1,3-butadiene in 2002. An extensive analysis conducted by TCEQ discusses dose-response modeling, estimating risk for the general population from occupational workers, estimating risk for potentially sensitive subpopulations, effect of occupational exposure estimation error, and use of mortality rates to predict incidence. The URF is 5.0 × 10⁻⁷ per μg/m³ or 1.1 × 10⁻⁶ per ppb and is based on a Cox regression dose-response model using restricted continuous data with age as a covariate, and a linear low-dose extrapolation default approach using the 95% lower confidence limit as the point of departure. Age-dependent adjustment factors were applied to account for possible increased susceptibility for early life exposure. The air concentration at 1 in 100,000 excess leukemia mortality, the no-significant-risk level, is 20 μg/m³ (9.1 ppb), which is slightly lower than the TCEQ chronic reference value of 33 μg/m³ (15 ppb) protective of ovarian atrophy. These values will be used to evaluate ambient air monitoring data so the general public is protected against adverse health effects from chronic exposure to 1,3-butadiene.     

Experiment-dependent priors in psychology and physics

Sometimes conducting an experiment to ascertain the state of a system changes the state of the system being measured. Kahneman & Tversky modelled this effect with support theory. Quantum physics models this effect with probability amplitude mechanics. As this paper shows, probability amplitude mechanics is similar to support theory. Additionally, Viscusi's proposed generalized expected utility model has an analogy in quantum mechanics.     

The Interaction Between Role Structures and Self-Conceptions in Fostering Different Types of Self-Esteem in Innovative and Traditional Elementary Schools*

A two-dimensional model of inner and outer self-esteem is discussed wherein inner self-esteem is hypothesized to be an outcome of self-evaluations of performance in prominent role identities. Outer self-esteem is hypothesized to be related to self-evaluations of both prominent and nonprominent role identities. The research context is a comparison of the different processes facilitating self-esteem in innovative schools (emphasis on student-initiated activities and control) and traditional (emphasis on pre-determined curriculum and teacher-administrator control). Data across school type demonstrate a modest correlation between positive self-evaluations of performance in prominent role identities and both types of self-esteem. The data suggest that high evaluation of performance in nonprominent role identities is related to outer self-esteem but not to inner self-esteem. Further empirical clarification of the concepts was established by viewing the relationships within school type. In the innovative schools both types of self-esteem were predominantly related to positive evaluations of prominent role identities, whereas in the traditional schools both types of self-esteem were related to both performance in prominent and nonprominent role identities. Thus the theoretical distinction gained partial support while the process of gaining self-esteem was shown to be essentially different between alternate school structures. Controls for social desirability, race, sex, and father's occupation did not change these findings.     

Processes of adjustment in organized out-of-school activities: opportunities and risks

Participation in organized out-of-school activities leads to long-term psychosocial and educational benefits for young people. Now we're learning which features of these activities best support individual children.     

Elites and popular nationalism

Much current theory concerning nationalism holds that elites commonly create or cause popular nationalism. In part, that thesis may be due to an overwhelming emphasis in research on nationalism on positive cases: cases where nationalism has appeared, ignoring cases where it has not. In this article, I challenge the thesis by showing numerous historical cases in which elites have promoted nationalisms that ordinary people have not adopted, or in which ordinary people have adopted a nationalism before it was taken up by elites. Even if elites do not create popular nationalism, however, they can and do shape its expression in a variety of ways, such as organizing it, providing relevant information, or providing opportunity or incentive for it. I show this through historical examples.     

The relationship of trauma exposure to sex offending behavior among male juvenile offenders

The most common type of adult and juvenile sex offender treatment utilizes a Relapse Prevention (RP) model. In RP clients learn about their offense cycle with an emphasis on recognizing high-risk situations and negative emotional states that can be precursors or triggers to offending behavior. This study identifies ways that traumatic experiences and trauma-associated feelings can be offense triggers for juvenile sex offenders. Researchers interviewed the treating clinicians of 40 male juvenile sex offenders who received at least six months of RP sex offender treatment. Results showed that 95% of the youths had experienced a Post Traumatic Stress Disorder (PTSD) Criterion A traumatic event and that 65% met criteria for PTSD based on clinician judgments. Overall, clinicians identified prior trauma exposure as being related to the offense triggers in 85% of offenders. Specifically, the following trauma-related feelings were identified as offense triggers: intense fear in 37.5% of sex offenders, helplessness in 55%, and horror in 20%. Implications for sex offender treatment programs are discussed.