An Improved Approximation to the Exact Solution of the Two-Stage Clonal Growth Model of Cancer

Multistage clonal growth models are of interest for cancer risk assessment because they can explicitly incorporate data on cell replication. Both approximate and exact formulations of the two stage growth model have been described. The exact solution considers the conditional probability of tumors arising in previously tumor-free animals; the approximate solution estimates total probability of tumor formation. The exact solution is much more computationally intensive when time-dependent cell growth parameters are included. The approximate solution deviates from the exact solution at high incidences and probabilities of tumor. This report describes a computationally tractable,'improved approximation'to the exact solution. Our improved approximation includes a correction term to adjust the unconditional expectation of intermediate cells based on the time history of formation of intermediate cells by mutation of normal cells (recruitment) or by cell division in the intermediate cell population (expansion). The improved approximation provided a much better match to the exact solution than the approximate solution for a wide range of parameter values. The correction term also appears to provide insight into the biological factors that contribute to the variance of the expectation for the number of intermediate cells over time.     

Review article: Norbert Elias – established or outsider?

The Civilizing Process: Volume 2, State Formation and Civilization Norbert Elias, Basil Blackwell, Oxford, 1982, £19.50. 376 pp. The Court Society Norbert Elias, Basil Blackwell, Oxford, 1983, £15.00. 301 pp.     

THE GREAT ALASKAN MONEY GIVE AWAY PROGRAM

For the past six years the State of Alaska has engaged in a unique program in which annual direct cash distributions have been made to the populace. These distributions represent in a sense dividend payments made to citizens on their individual shares of Alaska's mineral wealth. This paper provides a historic perspective of the Alaska dividend distribution program and examines actual distributions to determine whether they are consistent with utility maximization. We found that either a dramatic change in preferences took place over the past six years or that distributions were inconsistent with intertmporal utility maximization.     

Calculating the Hazard Function and Probability of Tumor for Cancer Risk Assessment When the Parameters Are Time-Dependent

The probability of tumor and hazard function are calculated in a stochastic two-stage model for carcinogenesis when the parameters of the mode are time-dependent. The method used is called the method of characteristics.     

Urban development programming: The problem of federal involvement and self‐evaluation

One government social service program that has been affected by the recent shift in political philosophy is the Urban Development Action Grant program (UDAG). Operated since 1977 by the Department of Housing and Urban Development (HUD), UDAG is intended to facilitate the creation of new employment opportunities in economically distressed areas. Awarded by the federal government to local public officials, UDAG funds are allocated to encourage private investment for industrial growth and expansion. These financial incentives, it is argued, serve as a catalyst for new employment opportunities created to assist the poor and the unemployed.

In the context of a cost‐benefit analysis, however, the UDAG program may be an example of fiscal extravagance and administrative malfeasance. Three UDAG case studies reported offer a sample of federally subsidized UDAG industrial projects. Discussion of these projects is intended as a partial analysis of the UDAG program. Other issues addressed include the role of federal officials in the UDAG monitoring process, the effectiveness of UDAG in creating new jobs, and the criteria employed by government officials to evaluate the UDAG program.     

Seeing Red,Tasting Blood: Sensual Citizenship on Christmas Island

Christmas Islanders participate together in blood metaphors, drawn from the island's biotic life. These metaphors proceed along specific sensual lines such that, in and through participation in this shared sensual citizenship, the identity category ‘Christmas Islanders’ is yielded. Pan-islandic sensory citizenship is based on participation in a highly visual and rhythmic auditory Christmas Island sensorium and other specifically ethnic relationships to the Island proceed primarily along the sensory lines of taste. Participation in particular sensory registers of island life is key in locating Christmas Islanders precisely as such, and is equally important in creating and maintaining ‘senses’ of ethnic difference between them. At the same time as local people participate together in pan-islandic metaphors, some ethnic groups have made sensory connections with the island that are not made by others. These connections are instrumental in locating islanders of particular ethnic membership as ‘native’ (over local), or as damaging to pan-islandic identity.     

Premarital sexual intercourse: A test of the effects of peer group,religiosity, and sexual guilt

Previous research findings have been inconsistent concerning the influence on a person's sexual behavior of the peer group's sexual behavior and approval. Therefore, in this paper the relative importance of one's closest, friends' sexual behavior, their perceived approval for engaging in premarital coitus. age, sex guilt, and conventional religiosity were examined. Respondents were 467 dormitory students from a large mid‐Atlantic university. Results of separate path analyses for men and women showed that the greater the number of close friends thought to be nonvirgins, the greater the likelihood the man was also nonvirgin. Anticipated approval from close friends was not associated with a man being a nonvirgin. For women, both the sexual behavior and the expected degree of approval from close friends was associated with a woman being a nonvirgin. For both sexes, sex guilt was negatively associated with being a nonvirgin, whereas the respondent's age and degree of conventional religiosity were not associated with the sexual behavior. The findings indicate that researchers should specify whether a peer group's standards, or behavior, is being considered.     

Parent Marital Quality and the Parent–Adolescent Relationship: Effects on Sexual Activity among Adolescents and Youth

The link between growing up outside of an intact family and the likelihood of engaging in risky sexual behaviors as an adolescent has been explored extensively. However, fewer studies examined the likelihood of risky sexual behaviors among adolescents within intact families and what elements of those married-parent families seem to function as protective factors for adolescents. This study looks at relationships within married-parent families—that is, the parent marital relationship, the youth–parent relationship, and the interaction of the two—to identify potential sources of resilience for adolescents that influence their sexual activity. Overall, the youths' relationship with their parents matters more than the parents' relationship with each other, particularly for male youth and youth in stepparent families. Other covariates with notable influence on youths' risky sexual behaviors include parents' marital disruption and religious activity during the teen years. Analyses are based on data from the NLSY97 cohort.     

Family Processes and Adolescent Religiosity and Religious Practice: View From the NLSY97

This article focuses on family processes and adolescent religious attendance and personal religiosity. We find that the closeness and quality of the marital relationship and relationship between adolescent and parents significantly contributes to the strength of adolescent religious conviction and practice. The study used data from the NLSY97 cohort. Predictors include parenting style, closeness, and parent–child closeness; family structure; income, employment, parental education, mother's age at first birth, and number of siblings; adolescent characteristics (e.g., age, gender, race/ethnicity, disability, lying or cheating); and environmental characteristics (e.g., region of country, urbanicity, and physical environment risk). Family religious attendance was dramatically influenced by race in adolescents aged 16 years. Adolescents living with married, biological parents in 1997 were 36% more likely to attend worship services than those living with stepfamilies. Adolescents living in more physically risky environments, with peers who belonged to gangs, cut classes, or had sex, were less likely to attend weekly worship services with their families. Finally, compared with adolescents whose parents had a high-quality marital relationship and who had good relationships with both parents, all other adolescents were less likely to attend weekly worship services with their families.