Need for an External Proficiency Testing Program for Cytokines, Chemokines, and Plasma Markers of Immune Activation

An external evaluation program for measuring the performance of laboratories testing for cytokines and immune activation markers in biological fluids was developed. Cytokines, chemokines, soluble cytokine receptors, and other soluble markers of immune activation (CSM) were measured in plasma from a healthy human immunodeficiency virus (HIV)-seronegative reference population and from HIV-seropositive individuals as well as in supernatant fluids from in vitro-stimulated human immune cells. The 14 components measured were tumor necrosis factor (TNF) alpha, gamma interferon, interleukin-1 (IL-1), IL-2, IL-4, IL-6, IL-10, Rantes, MIP-Ia, MIP-Iβ, soluble TNF receptor II, soluble IL-2 receptor alpha, β(2)-microglobulin, and neopterin. Twelve laboratories associated with the Adult and Pediatric AIDS Clinical Trial Groups participated in the study. The performance features that were evaluated included intralaboratory variability, interlaboratory variability, comparison of reagent sources, and ability to detect CSM in the plasma of normal subjects as well as the changes occurring in disease. The principal findings were as follows: (i) on initial testing, i.e., before participating in the program, laboratories frequently differed markedly in their analytic results; (ii) the quality of testing of a CSM in individual participating laboratories could be assessed; (iii) most commercial kits allowed distinction between normal and abnormal plasma CSM levels and between supernatants of stimulated and unstimulated cells; (iv) different sources of reagents and reference standards frequently provided different absolute values; (v) inexperienced laboratories can benefit from participating in the program; (vi) laboratory performance improved during active participation in the program; and (vii) comparability between analyses conducted at different sites can be ensured by an external proficiency testing program

The People’s Hired Guns? Experimentally Testing the Inclination of Prosecutors to Abuse the Vague Definition of Crimes

Legal realists expect prosecutors to be selfish. If they get the defendant convicted, this helps them advance their careers. If the odds of winning on the main charge are low, prosecutors have a second option. They can exploit the ambiguity of legal doctrine and charge the defendant for vaguely defined crimes, like conspiracy. We model the situation as a signalling game and test it experimentally. If we have participants play the naked game, at least a minority plays the game theoretic equilibrium and use the vague rule if a signal indicates that the defendant is guilty. This becomes even slightly more frequent if a misbehaving defendant imposes harm on a third participant. By contrast if we frame the situation as a court case, almost all prosecutors take the signal at face value and knowingly run the risk of loosing in court if the signal was false. Our experimental prosecutors behave like textbook legal idealists, and follow the urge of duty