Utility of immunoassay in drug screening in skeletal tissues: sampling considerations in detection of ketamine exposure in femoral bone and bone marrow following acute administration using ELISA

Detection of ketamine exposure in skeletal tissues by automated enzyme-linked immunosorbent assay (ELISA) and gas chromatography with electron capture detection (GC-ECD) is described. Rats (n = 18) received 0, 15, 30, or 75 mg/kg ketamine hydrochloride acutely (i.p.), and were euthanized within 15 min or 1 h. Ketamine was extracted from ground femoral bone by methanolic incubation followed by liquid-liquid extraction (LLE), while marrow was homogenized in alkaline solution, and then underwent LLE. Extracts were analyzed by ELISA, and subsequently by GC-ECD following derivatization with trifluoroacetic acid anhydride. The effect of tissue type (i.e., diaphyseal bone vs. epiphyseal bone vs. bone marrow) on the immunoassay response was examined through determination of binary classification test sensitivity (S) and measurement of the relative decrease in absorbance (%DA, drug-positive tissues vs. drug-free controls) in each tissue type. The %DA varied significantly between different tissues examined under a given dose condition, and generally decreased in the order marrow > epiphyseal bone > diaphyseal bone, at all dose levels examined. Measured S values for marrow, epiphyseal bone, and diaphyseal bone were 100%, 77%, and 23%, respectively (75 mg/kg dose). These results suggest that the type of skeletal tissue sampled and position sampled within a given bone (diaphyses vs. epiphyses) are important parameters in drug screening of skeletal tissues.     

The Role of Perceived Stress and Self-Efficacy in Young People’s Life Satisfaction: A Longitudinal Study

Life satisfaction is an important indicator of successful development. However, adolescents’ life satisfaction tends to be relatively unsteady, and environmental influences play a critical role in shaping life satisfaction among adolescents in the transition to young adulthood. Given the paramount importance that education plays in adolescents’ lives, adolescents’ life satisfaction may vary as a function of school-related stress experience. At the same time, coping resources may help reduce adverse effects of stress on life satisfaction. With this in mind, we examined whether, and to what extent, perceived stress in education and general self-efficacy (a resource that facilitates coping) affect the life satisfaction of adolescents in transition to young adulthood. We distinguished between baseline levels of stress and self-efficacy and within-person change in stress and self-efficacy to determine whether life satisfaction is sensitive to fluctuations in stress and self-efficacy when person-specific levels of stress and self-efficacy are taken into account. Estimating growth curve models on data from a panel study on the life trajectories of compulsory-school leavers (n?=?5126, 55.3?% female), we found that baseline levels of stress and self-efficacy, as well as within-person change in stress and self-efficacy, affected adolescents’ life satisfaction. Moreover, our results showed that baseline self-efficacy mitigated the negative effect of baseline stress on life satisfaction. These findings improve our understanding of two major psychological determinants of adolescents’ life satisfaction and extend our knowledge of life satisfaction trajectories during the transition to young adulthood.     

Investing in multi-stakeholder dialogue to address natural resource competition and conflict

How can multi-stakeholder dialogue help assess and address the roots of environmental resource competition and conflict? This article summarises the outcomes and lessons from action research in large lake systems in Uganda, Zambia, and Cambodia. Dialogues linking community groups, NGOs and government agencies have reduced local conflict, produced agreements with private investors, and influenced government priorities in ways that respond to the needs of marginalised fishing communities. The article details policy guidance in four areas: building stakeholder commitment, understanding the institutional and governance context, involving local groups in the policy reform process, and embracing adaptability in programme implementation.     

Measuring changes in women's empowerment and its relationship to intimate partner violence

This article uses survey data to examine changes over time in the relationship between women’s empowerment and intimate partner violence (IPV) in six Bangladeshi villages. Prior analyses using a limited set of empowerment indicators available in both 2002 and 2014 suggested a persistent positive association between empowerment and IPV. The article’s analysis, using an updated set of measures derived from extensive qualitative studies, suggests that empowerment may be shifting from a risk factor for IPV to a protective factor. The article discusses the methodological limitations posed by the shifting manifestations of empowerment and its social meanings within and across settings.     

How Weakly Institutionalized Parties Monitor Brokers in Developing Democracies: Evidence from Postconflict Liberia

Political parties in sub-Saharan Africa's developing democracies are often considered to lack sufficiently sophisticated machines to monitor and incentivize their political brokers. We challenge this view by arguing that the decentralized pyramidal structure of their machines allows them to engage in broker monitoring and incentivizing to mobilize voters, which ultimately improves their electoral performance. This capacity is concentrated (a) among incumbent parties with greater access to resources and (b) where the scope for turnout buying is higher due to the higher costs of voting. Using postwar Liberia to test our argument, we combine rich administrative data with exogenous variation in parties' ability to monitor their brokers. We show that brokers mobilize voters en masse to signal effort, that increased monitoring ability improves the incumbent party's electoral performance, and that this is particularly so in precincts in which voters must travel farther to vote and thus turnout buying opportunities are greater.