A Numerical Solution to the Nonhomogeneous Two-Stage MVK Model of Cancer

In this article, we describe a straightforward method for solving the probability of at least one malignant cell by time t, and the associated hazard function, in the general (i.e., nonhomogeneous) two-stage Moolgavkar-Venzon-Knudson (MVK) model of cancer. The method consists of solving four coupled ordinary differential equations derived from the Kolmogorov backward equations for this process. The relationship of this method to previously proposed solutions is discussed.     

Resilience in low-income African American women living and aging with HIV

Women are living with HIV into middle and older age and are likely to face multiple comorbidities and stressors as they age. This study focused on understanding how women who experience multiple forms of oppression and ongoing adversity are still able to adapt and stand strong. Using a theoretical framework of resilience and a feminist research ideology, interviews of eight middle-aged and older African American women living with HIV were analyzed. Despite experiences of HIV-related discrimination, trauma, and violence, these women demonstrated a remarkable ability to adapt and maintain support. Implications for research and practice are discussed.     

Determinants of Infant Mortality in Older ASEAN Economies

Infant mortality in the Association of Southeast Asian Nations (ASEAN) has been declining, yet disparities remain between the nations. This paper therefore explores the determinants of infant mortality in the older ASEAN-4 economies, Malaysia, Thailand, Indonesia and the Philippines using an Autoregressive Distributed Lag (ARDL) Error Correction Model framework. The key findings of the study are: First, there is evidence of long-run relationships among infant mortality, education, female fertility, income and access to healthcare. Second, the determinants of infant mortality vary between countries. Female fertility emerged as the main determinant of infant mortality in Malaysia, while access to healthcare matter for infant mortality in Indonesia, and to a lesser extent for the Philippines. The income effect is significant for reducing infant mortality in Malaysia, while female education is important for Indonesia and Thailand. Third, the speed of adjustment of infant mortality rate is comparatively low in ASEAN-4.     

Dynamic selection of dispatching rules for job shop scheduling

Although the academic contribution to job shop scheduling is abundant, its impact on practice has been minimal. The most preferred approach to job shop scheduling in the industry is dispatching rules. A major criticism against dispatching rules is that there is no single universal rule. The effective choice of dispatching rules depends on the scheduling criterion and existing job shop conditions. In this paper, the authors have proposed a scheduling method based on the analytic hierarchy process, that dynamically selects the most appropriate dispatching rule from several candidate rules. The selection is based on the existing job shop conditions. This method is applied to two formal job shop problems, and the results for single dispatching rules are inferior to the method proposed in this paper.     

Corporate planning in domestic airlines— An Indian case study

In this article the author considers the problems of planning in the airline industry, drawing specifically on experience in the domestic Indian airline. The article seeks to examine some of the strategic issues relevant to domestic airlines which, while related here to the Indian environment, may be seen to be pertinent in most developing countries.     

Key strategic issues for public corporations

The public sector organisations play a dominant role in the economies of many countries and they are particularly important in developing economies. However, management in such organisations face special problems in corporate planning. In particular, they have as yet no clear-cut definition of their social and economic objectives, no accepted way of pricing so as to deal with ‘social overheads’ and no valid way of measuring performance in industries where low profitability is to be expected.     

Uncertainties in Biologically-Based Modeling of Formaldehyde-Induced Respiratory Cancer Risk: Identification of Key Issues

In a series of articles and a health-risk assessment report, scientists at the CIIT Hamner Institutes developed a model (CIIT model) for estimating respiratory cancer risk due to inhaled formaldehyde within a conceptual framework incorporating extensive mechanistic information and advanced computational methods at the toxicokinetic and toxicodynamic levels. Several regulatory bodies have utilized predictions from this model; on the other hand, upon detailed evaluation the California EPA has decided against doing so. In this article, we study the CIIT model to identify key biological and statistical uncertainties that need careful evaluation if such two-stage clonal expansion models are to be used for extrapolation of cancer risk from animal bioassays to human exposure. Broadly, these issues pertain to the use and interpretation of experimental labeling index and tumor data, the evaluation and biological interpretation of estimated parameters, and uncertainties in model specification, in particular that of initiated cells. We also identify key uncertainties in the scale-up of the CIIT model to humans, focusing on assumptions underlying model parameters for cell replication rates and formaldehyde-induced mutation. We discuss uncertainties in identifying parameter values in the model used to estimate and extrapolate DNA protein cross-link levels. The authors of the CIIT modeling endeavor characterized their human risk estimates as "conservative in the face of modeling uncertainties." The uncertainties discussed in this article indicate that such a claim is premature.     

Contesting Water Rights: Collective Ownership and Struggles against Privatization

The post‐1980s have seen increasing struggles over rights to water. Water rights have involved intense protests and campaigns against privatization of water including bottling of water and advocacy for citizens control of water. We review scholarly work to focus on four main aspects: the complexities intertwining globalization processes, the state, and water rights; collective ownership of water resources; peoples’ participating in managing and using water; and the campaigns against privatization which have emerged in both the developing and developed world in different ways. The conclusion calls for adopting a social movement lens to examine the struggles for water rights by providing some lead research questions around the macro and micro level theoretical approaches.     

Sociodemographic Correlates and Morbidity in Lottery Gamblers: Results from a Population Survey

The aim of the current study was to examine the socio-demographic correlates, the association of mental and physical illness, and the prevalence of pathological gambling among three groups (1) those with lottery gambling only (2) those with lottery and other types of gambling and (3) those with other types of gambling only—such as playing cards, sports betting, horse racing, casino gambling etc. Data was used from a nationwide cross-sectional epidemiological nationally representative survey of the resident (Singapore Citizens and Permanent Residents) population in Singapore of 6616 Singaporean adults aged 18 years and older. All respondents were administered the South Oaks Gambling Screen to screen for pathological gambling. The diagnoses of mental disorders were established using the Composite International Diagnostic Interview and relevant socio-demographic data was collected using a structured questionnaire. Lottery gambling was by far the most popular form of gambling in Singapore, with 83.5 % of those who had ever gambled indicating that they had participated in lottery gambling. Those who participated in lottery gambling alone were more likely to belong to the older age group (as compared to the 18–35 years age group), be of Indian ethnicity, have a secondary or vocational education, and earn a lower income as compared to the other two groups. Our findings that those with pure lottery gambling were significantly less likely to be pathological gamblers and had significantly lower odds of psychiatric and physical morbidity as compared to the other two groups are unique and need further research.