The persistence of senescence

Senescence is a potent anticancer mechanism, representing a barrier that most, if not all, would-be tumor cells must traverse on their path to malignant transformation. In this Perspective, I discuss two recent publications (1, 2) that deal with the durability of senescence. These findings are of interest not only to those who study aging, but to those who study cancer as well.     

Time period and lesbian identity events: a comparison of Norwegian lesbians across 1986 and 2005

The purpose of the present work was to investigate the assumption that the lives of lesbians are easier today. When exploring the hypothesis that identity events (e.g., coming out to parents) among lesbian women have changed over time and happen earlier in life today, we expected to find several time period effects. Two national samples obtained through mailed questionnaires were compared, 1986 (n = 123) and 2005 (n = 236), age range 20-49. Time period effects were found, including informants reporting identifying as lesbian earlier in life. Time period effects, however, were not found regarding relational identity events such as informing others about one's identity status. The findings did not reveal any conclusive evidence that it is easier to establish a lesbian lifestyle today.     

Developing strategies for deriving small population fertility rates

Many agencies require population estimates and projections by ethnic group. These projections need ethnic-specific, age-specific fertility rates (ASFRs) but their inclusion is challenging since ethnicity is not recorded at birth registration. In this paper maternity data are used in a case study of electoral wards in Bradford, West Yorkshire, to develop fertility rates for small populations for a 1991 based projection. The challenge is to capture local variations in fertility by ethnic group when data are sparse. Small areas were grouped together using cluster analysis to define combinations with similar sociodemographic and fertility experiences so that sparse data could be aggregated to estimate reliable ethnic-specific fertility rates. For comparison, the data were aggregated into the 1991 Office for National Statistics area type classification. Fertility rates by single year of age for all area types were smoothed using the Hadwiger function. For the White ethnic group there were sufficient births to create ethnic-specific, ward-level ASFRs. For other ethnicities grouping of areas was necessary. The accuracy of the ASFRs in predicting births was assessed using mean absolute percentage error. Results show that for some minority groups district-level ethnic-specific fertility rates produced the most accurate birth estimates even though they were based on a larger area. This implies that rates created may be informative about the local area for White ethnic type but not in the same way for smaller ethnic groups. In terms of grouping strategies we recommend that existing classifications are assessed to determine how well variations in rates are stratified before embarking on a custom scheme. Where population sub-groups are small in some areas, it may be more reliable to use rates derived for larger areas and apply these to local populations. Inevitably, the rates used in a projection are a compromise but hopefully will still capture important dimensions of population change.     

Confounding issues related to determining sample size in qualitative research

The debate on determining sample size in qualitative research is confounded by four fundamental methodological issues: the exclusive focus on theme analysis; the diverse and imprecise use of ‘qualitative’; a reliance on only two logics of inquiry, induction and deduction, and the occasional confusion of abduction with induction; and a general lack of recognition of the importance of differences in ontological assumptions. Embedded in these issues is an unwarranted acceptance of limited associations between certain assumptions, logics, forms of data, and methods of data collection/generation and analysis. What is required is a reformulation of the problem and its discussion with reference to ontological assumptions and logics of inquiry.     

Inclusion,exclusion or indifference? Redefining migrant and refugee host state engagement options in Mediterranean ‘transit’ countries

What determines policies toward migrants and refugees in the transit-turned-host countries? Compared to the vast literature examining migration to Europe and North America, we know relatively little about why ‘newer’ host states pursue a liberal strategy with access to residency, employment and services on par with citizens, or what drives them to treat migrants and refugees with exclusion. This paper argues that there is a third choice: the idea of indifference-as-policy. Indifference refers to indirect action on the part of the host state, whereby a state defers to international organisations and civil society actors to provide basic services to migrants and refugees. The paper uses data collected over two years in Egypt, Morocco and Turkey to examine how this tripartite understanding of engagement maps onto empirical reality. Drawing on this analysis, the argument in this paper is two-fold. First, indifference is a strategic form of engagement utilised by host states, and that it creates a specific type of environment that allows for the de facto integration of migrants and refugees. Second, even when host states take steps toward a more liberal engagement strategy, examining policy outcomes, rather than outputs, demonstrates that indifference is still the dominant policy.     

SCAT AND SPAT: LARGE-SCALE COMPUTER-BASED OPTIMIZATION SYSTEMS FOR THE PERSONNEL ASSIGNMENT PROBLEM

The personnel assignment problem involves the assignment of people to tasks, projects, etc., in a manner that maximizes a measure of aggregate utility for the assignees subject to several assignment constraints. In addition to computationally efficient solution algorithms, the effective implementation of mathematical models to solve the personnel assignment problem must include data processing systems with comprehensive error checking/resolution procedures, end user reports, documentation, and training. This paper summarizes two successful computer-based systems for solving large-scale personnel assignment problems that frequently occur in university settings. SCAT, the Student-Company Assignment Technique, assigns students to job interview slots. SPAT, the Student-Project Assignment Technique, assigns students to project teams in an MBA field project course. The SCAT and SPAT approaches can be generalized to a wide variety of personnel assignment problems in university, industry, government, and military settings.