Use of bleach to eliminate contaminating DNA from the surface of bones and teeth

The extraction of DNA from archaeological or forensic skeletal remains can provide quite powerful data for analysis, but is plagued by a unique set of methodological problems. One of the most important methodological problems to overcome in such analyses is the presence of modern contamination on the surfaces of bones and teeth, which can lead to false positives and erroneous results unless it is removed before DNA extraction is initiated. Ancient DNA (aDNA) researchers and forensic scientists have employed a number of techniques to minimize such contamination. One such technique is the use of bleach (sodium hypochlorite--NaOCl) to "destroy" contaminating DNA. However, a consensus on the optimum concentration of sodium hypochlorite to be used and the amount of time the bone or tooth should be exposed to it has not emerged. The present study systematically approaches the issue by introducing contamination to ancient bones (from approximately 500 BP) and determining which of several sodium hypochlorite treatments best eliminates surface contamination. The elimination of surface contamination from bone requires immersion in at least 3.0% (w/v) sodium hypochlorite (approximately equal parts of commercial bleach and water) for at least 15 min. Endogenous DNA proved to be quite stable to even extreme sodium hypochlorite treatments (6% for 21 h), suggesting that DNA adsorbs to hydroxyapatite in the bone and that this process facilitates the preservation of DNA in ancient skeletal remains.     

Intra-country regulation of share markets: does one size fit all?

A large body of evidence suggests that financial development is greater in countries that impose stricter regulatory requirements on their major stock exchanges, but this leaves open the question of whether or not such regulation should be uniformly applied to all equity trading platforms within a country. On the one hand, regulatory variation permits a wider choice of investment opportunities for investors, lowers the cost of capital for some firms, and enhances price discovery and efficiency. On the other hand, the presence of lightly regulated exchanges can potentially have adverse spillover implications for a country’s other financial markets.

The Developmental Significance of Adolescent Romantic Relationships: Parent and Peer Predictors of Engagement and Quality at Age 15

From a longitudinal sample (n = 957; 49.9% male; 77.3% White/non-Hispanic) of participants studied from infancy through age 15, adolescents’ depth of engagement in, and quality of romantic relationships were predicted from early and contemporaneous parent–child interactive quality and peer social competence. High quality maternal parenting and peer experiences prior to and during adolescence tended to be negatively associated with the depth of engagement in this domain for the full sample, yet positively associated with the quality of adolescents’ romantic relationships for the sub-set of individuals currently dating at age 15. Results reconcile contrasting views of the origins of romantic relationship engagement and quality and the positive versus negative developmental salience of romantic relationships in adolescence.     

Earning through learning in legislatures

This inquiry applies Gary Becker’s theoretical notions of general and specific training to the experiential learning that occurs within political institutions, in particular the U.S. Congress. In the process, we isolate economic facets of these legislative experiences that influence the rental-value of human capital derived from congressional training. We identify four factors that structure legislators’ post-elective wages: pre-congressional salary, year of entry, tenure, and variables closely related to general training in Congress—specifically, assignment to powerful legislative committees, acquisition of broad skill packages, investment in expanding skill-set proficiencies, and to a lesser extent, life-cycle driven declines in such investments.     

Attachment and social bonding in maximum and minimum security prison inmates

Attitudes towards social attachment and bonding were evaluated in groups of maximum (N=48) and bonding were evaluated in groups of maximum (N=46) security prison inmates and compared with the attitudes of a group of 49 noncriminal college students. Three primary styles of attachment were considered: avoidant, ambivalent/anxious, and secure. It was predicted that the maximum security condition, a group hypothesized to contain a large number of lifestyle criminals, would evidence more of an avoidant style of attachment compared to minimum security inmates or a group of college student controls. Consistent with this hypothesis, the maximum security inmates exhibited greater avoidance in their attitudes towards relationships than subjects in the other two conditions. The implications of these results are discussed.     

Lifestyle criminality from a developmental standpoint

A theory which details the development of lifestyle criminality is discussed. The necessary (but not sufficient) early conditions for the development of later criminality involve improper resolution of three early developmental tasks which confront all children (social attachment, stimulus modulation, self-image). A child predisposed to later criminality by weak social bonding, a high need for excitement, and a negative self-image is made even more vulnerable when exposed to such additional influences as low verbal intelligence, a chaotic home environment, or antisocial peers. Despite the importance of these variables, however, it is the lifestyle choices one makes which determine later criminality.     

Contentious Politics and Democratization: Comparing the Impact of Social Movements on the Fall of Communism in Eastern Europe

In this paper, I identify and analyze the interaction between two processes - mobilization and bargaining - by which democratic challengers can transform political institutions, bringing together insights from the literatures on social movements, which tends to analyze movement emergence, and democratization, which tends to analyze the design of democratic institutions. I compare the impact of social movements in the fall of communism in Eastern Europe, cases that offer a valuable opportunity to extend the literature on contentious politics beyond its origins in the study of Western parliamentary democracies. The analysis directs attention to an under examined arena of political contestation, agenda setting, or the process by which the demands of social movements are translated into issues for governments. The paper argues that the traditional dichotomy between institutional and non-institutionalized contention has obscured the ways that democratic challengers not only pressure states from the outside but transform them through new forms of political participation. Finally, it considers alternative explanations and suggests new directions for comparative research across different settings and times.