Using PCA scores to classify species communities: An example for pelagic seabird distribution

Using Principal Component Analysis (PCA) in order to classify animal communities from transect counts is a widely used method. One problem with this approach is determining an appropriate cut-off point on the Principal Component (PC) axis to separate communities. We have developed a method using the distribution of PC scores of individual species along transects from the PIROP (Programme Intégréde Recherches sur les Oiseaux Pélagiques) database for seabirds at sea in the Northwest Atlantic in winter 1965- 1992. This method can be applied generally to wildlife species, and also facilitates the evaluation, justification and stratification of PCs and community classifications in a transparent way. A typical application of this method is shown for three Principal Components; spatial implications of the cut-off decision for PCs are also discussed, e.g. for habitat studies.     

Methodological triangulation in researching families: Making sense of dissonant data

The research literature on triangulation has paid little attention to the problematic of 'making sense of dissonant data'. Nor has there been much discussion around the use of the technique of triangulation when researching families. Through a presentation of research findings gathered from self-report questionnaires and in-depth interviews with couples and families the possibilities of convergent, complementary and dissonant data and their interpretation are explored. The paper reflects on the ontological, epistemological and methodological tensions that must be negotiated when working with triangulated data. It is argued that given the multi-faceted context and intimate subject matter in family and couples research there is a high likelihood of dissonant findings. Recommendations are made for family researchers interested in the technique of triangulation to consider the context and process of their research in the interpretation of their data. Despite the challenges that triangulation throws up for researchers, it is argued that working within a post-positivist paradigm, triangulation enables analysis which is both more complex and more meaningful.     

Comparison of conflict of interest policies and reported practices in academic medical centers in the United States

The authors reviewed the conflict of interest policies of 9 academic medical centers in the United States and interviewed members of the Institutional Review Boards (IRBs) and Conflict of Interest Committees (COICs) at those institutions. They found that many institutions used processes for reporting and managing conflicts of interest that were more decentralized than the processes described in their policies. Also, most institutions had no clear and comprehensive policy to guide investigators regarding disclosure of conflicts of interest to potential research participants. Considerable differences in understanding of conflict of interest policies were observed between IRB and COIC officials.     

Explaining Diversityin the Development of Same-Sex Sexuality Among Young Women

This article summarizes findings from two ongoing studies charting the development of 167 adolescent and young adult sexual-minority women. Resultsdocument considerable variation in the quality, relative distribution, and context of women's same-sex and other-sex attractions. Furthermore, contrary to conventional wisdom, the timing of a woman's first same-sex attractions is not systematically related to subsequent features of sexual identity development. Rather, the quality and context of a woman'searly attractions and behavior is more important. We argue that variability in sexual-minority and heterosexual women's development is best explained by interactions between personal characteristics and environmental contexts, and we urge future studies of the sexual-minority life course to include women with same-sex attractions that do not identify as lesbian or bisexual.     

EFFECTIVE EUROPEAN ANTITRUST: DOES EC MERGER POLICY GENERATE DETERRENCE?

We estimate the deterrence effects of European Commission (EC) merger policy instruments over the 1990–2009 period. Our empirical results suggest phase‐1 remedies uniquely generate robust deterrence as—unlike phase‐1 withdrawals, phase‐2 remedies, and preventions—phase‐1 remedies lead to fewer merger notifications in subsequent years. Furthermore, the deterrence effects of phase‐1 remedies work best in high‐concentration industries, that is, industries where the Herfindahl Hirschman Index is above the 0.2 cut‐off level employed by the EC. Additionally, we find phase‐1 remedies do not deter clearly pro‐competitive mergers, but do deter potentially anti‐competitive mergers in high‐concentration industries. (JEL K21, K40, L40)     

"Fundamental causes" of social inequalities in mortality: a test of the theory

Medicine and epidemiology currently dominate the study of the strong association between socioeconomic status and mortality. Socioeconomic status typically is viewed as a causally irrelevant "confounding variable" or as a less critical variable marking only the beginning of a causal chain in which intervening risk factors are given prominence. Yet the association between socioeconomic status and mortality has persisted despite radical changes in the diseases and risk factors that are presumed to explain it. This suggests that the effect of socioeconomic status on mortality essentially cannot be understood by reductive explanations that focus on current mechanisms. Accordingly, Link and Phelan (1995) proposed that socioeconomic status is a "fundamental cause" of mortality disparities-that socioeconomic disparities endure despite changing mechanisms because socioeconomic status embodies an array of resources, such as money, knowledge, prestige, power, and beneficial social connections, that protect health no matter what mechanisms are relevant at any given time. We identified a situation in which resources should be less helpful in prolonging life, and derived the following prediction from the theory: For less preventable causes of death (for which we know little about prevention or treatment), socioeconomic status will be less strongly associated with mortality than for more preventable causes. We tested this hypothesis with the National Longitudinal Mortality Study, which followed Current Population Survey respondents (N = 370,930) for mortality for nine years. Our hypothesis was supported, lending support to the theory of fundamental causes and more generally to the importance of a sociological approach to the study of socioeconomic disparities in mortality.     

AIDS, Sexuality and African American Adolescent Females

Many African American adolescent females do not have sufficient information to break the cycle of unintended pregnancy and sexually transmitted diseases, in a society where we are bombarded from dusk to dawn with sexually explicit images. Knowledge alone does not change behavior, but it does provide the basis for decisions that promote sexual health. Adolescents are too often driven by curiosity and pressure to perform sexually. The ability to make the right decisions about sex is a skill that develops slowly throughout life. However, teens are impulsive and possess an attitude of invincibility. Youth cannot rely on the community to educate them about the dangers of unprotected sex. The African American community has never welcomed the topic of sexuality into our homes. Presently, the age old tradition of telling youth what they should and should not do without giving them the specific information about sex or sexual behavior continues. Prevention must be strongly emphasized. Schools must play role in the war against irresponsible sexual behavior and AIDS. This paper will describe an innovative group project designed to educate African American female teens about sexuality in an urban school setting. The topic of sex generated confusing and powerful feelings that were expressed in the group. Group members learned how to protect themselves, nurture themselves and value themselves. The goal of the group was to impart knowledge, change risky behaviors, validate their existence and listen to their stories.