Stable isotope ratio mass spectrometry and physical comparison for the forensic examination of grip-seal plastic bags

Plastic bags are frequently used to package drugs, explosives and other contraband. There exists, therefore, a requirement in forensic casework to compare bags found at different locations. This is currently achieved almost exclusively by the use of physical comparisons such as birefringence patterns. This paper discusses some of the advantages and shortcomings of this approach, and presents stable isotope ratio mass spectrometry (IRMS) as a supplementary tool for effecting comparisons of this nature. Carbon and hydrogen isotopic data are presented for sixteen grip-seal plastic bags from a wide range of sources, in order to demonstrate the range of values which is likely to be encountered. Both isotopic and physical comparison (specifically birefringence) techniques are then applied to the analysis of rolls of bags from different manufacturing lots from a leading manufacturer. Both approaches are able to associate bags from a common production batch. IRMS can be applied to small fragments which are not amenable to physical comparisons, and is able to discriminate bags which could be confused using birefringence patterns alone. Similarly, in certain cases birefringence patterns discriminate bags with similar isotopic compositions. The two approaches are therefore complementary. When more than one isotopically distinct region exists within a bag (e.g. the grip-seal is distinct from the body) the ability to discriminate and associate bags is greatly increased.     

Are Family Meals as Good for Youth as We Think They Are? A Review of the Literature on Family Meals as They Pertain to Adolescent Risk Prevention

Regular family meals have been shown to reduce adolescents’ engagement in various risk behaviors. In this article, we comprehensively examine the literature to review the association between family meals and eight adolescent risk outcomes: alcohol, tobacco, marijuana and other drugs; aggressive and/or violent behaviors; poor school performance; sexual behavior; mental health problems; and disordered eating patterns. The majority of the studies reviewed found associations in the relationship between family meals and adolescents’ risk profiles. More specifically, studies reporting significant associations found that adolescents who frequently ate meals with their family and/or parents were less likely to engage in risk behaviors when compared to peers who never or rarely ate meals with their families. Additionally, the influence of family meal frequency on youth risk outcomes appears to be dependent on gender, with family meals being a protective factor for females and males differently, depending on the outcome examined. However, the studies available about family meals and adolescent risk only examined the effect of family meal frequency, and not other components of family meals that contribute to the protective effect, and, thus, hinder the understanding of the mechanisms unique to family meals’ protective characteristics. Regardless of these limitations, the studies examined indicate that family meals may be protective and, therefore, have practical implications for parents, clinicians, and organizations looking to reduce adolescent risk behaviors. However, further examination is needed to better understand the mechanisms that contribute to the protective effect afforded by family meal frequency on adolescents.     

The Logic of Coercion in Cyberspace

What are the dynamics of coercion in cyberspace? Can states use cyber means as independent tools of coercion to influence the behavior of adversaries? This article critically assesses traditional coercion theory in light of cyberspace's emergence as a domain in which states use force, or its threat, to achieve political objectives. First, we review the core tenets of coercion theory and identify the requisites of successful coercion: clearly communicated threats; a cost–benefit calculus; credibility; and reassurance. We subsequently explore the extent to which each of these is feasible for or applicable to the cyber domain, highlighting how the dynamics of coercion in cyberspace mimic versus diverge from traditional domains of warfare. We demonstrate that cyber power alone has limited effectiveness as a tool of coercion, although it has significant utility when coupled with other elements of national power. Second, this article assesses the viability and effectiveness of six prominent warfighting strategies in the traditional coercion literature as applied to the cyber domain: attrition, denial, decapitation, intimidation, punishment, and risk. We conclude that, based on the current technological state of the field, states are only likely to achieve desired objectives employing attrition, denial, or decapitation strategies. Our analysis also has unique implications for the conduct of warfare in cyberspace. Perhaps counterintuitively, the obstacles to coercion that our analysis identifies may prompt states to reevaluate norms against targeting civilian infrastructure.     

Caution in the Classroom: K-12 Teacher In-Class Speech,The Federal Courts and Garcetti

The federal courts’ approach to regulating K-12 public school teacher speech in the classroom has been split during the past twenty years. Some circuit courts use Pickering v. Board of Education, in which speech is examined to see if it touches on a matter of public concern. Others prefer Hazelwood v. Kuhlmeier, which focuses on whether speech is school-sponsored and whether the school had a legitimate reason for restricting it. In 2007, Garcetti v. Ceballos offered a new perspective on public employee speech. In that case, speech was examined to determine whether it was related to an employee's professional duties. An examination of federal court treatment of in-class teacher speech before and after Garcetti shows the case has further complicated the issue because it is being embraced by some federal courts as an appropriate precedent when dealing with classroom speech.     

The Return of ‘Social Europe’: Ideas and Positions of German Parties towards the Future of European Integration

Politics in Eastern Europe. By George Schöpflin. Oxford: Blackwell, 1993. £12.99 pb.

Eastern Europe since 1945. By Geoffrey Swain and Nigel Swain. Basingstoke and London: Macmillan, 1993. £10 pb.

Revolution in East‐Central Europe. The Rise and Fall of Communism and the Cold War. By David S. Mason. Boulder, San Francisco and Oxford: Westview Press, 1992. £9.50 pb.

Surge to Freedom: The End of Communist Rule in Eastern Europe. By J.F. Brown. Twickenham: Adamantine Press, 1991. £18.40 pb.

The New Democracies in Eastern Europe. Party Systems and Political Cleavages. Edited by Sten Berglund and Jan Åke Dellenbrant. Aldershot: Edward Elgar, 1991. £39.95 hb.

Developments in Eastern European Politics. Edited by Stephen White, Judy Batt and Paul G. Lewis. Basingstoke and London: Macmillan, 1993. £11.99 pb.     

Learning from Diversity: A Theoretical Exploration

Public-sector organizations tend to be more racially and ethnically diverse than private-sector organizations, leading to the challenge of enhancing heterogeneous work group effectiveness. Recent work suggests that a group's "diversity perspective," or set of beliefs about the role of cultural diversity, moderates diverse group performance. One perspective, the integration and learning perspective, argues that heterogeneous groups function better when they believe that cultural identities can be tapped as sources of new ideas and experiences about work. However, simply holding the integration and learning perspective may not be sufficient. Research on general group learning has shown that it requires particular behaviors and cognitive frames. This article integrates recent work on diversity perspectives with long-standing research on team learning to propose a conceptual model of learning in culturally diverse groups. It suggests that both the integration and learning perspective and more generic learning frames and skills must be present.