Vector Transmission of Leishmania Abrogates Vaccine-Induced Protective Immunity

Numerous experimental vaccines have been developed to protect against the cutaneous and visceral forms of leishmaniasis caused by infection with the obligate intracellular protozoan Leishmania, but a human vaccine still does not exist. Remarkably, the efficacy of anti-Leishmania vaccines has never been fully evaluated under experimental conditions following natural vector transmission by infected sand fly bite. The only immunization strategy known to protect humans against natural exposure is “leishmanization,” in which viable L. major parasites are intentionally inoculated into a selected site in the skin. We employed mice with healed L. major infections to mimic leishmanization, and found tissue-seeking, cytokine-producing CD4+ T cells specific for Leishmania at the site of challenge by infected sand fly bite within 24 hours, and these mice were highly resistant to sand fly transmitted infection. In contrast, mice vaccinated with a killed vaccine comprised of autoclaved L. major antigen (ALM)+CpG oligodeoxynucleotides that protected against needle inoculation of parasites, showed delayed expression of protective immunity and failed to protect against infected sand fly challenge. Two-photon intra-vital microscopy and flow cytometric analysis revealed that sand fly, but not needle challenge, resulted in the maintenance of a localized neutrophilic response at the inoculation site, and removal of neutrophils following vector transmission led to increased parasite-specific immune responses and promoted the efficacy of the killed vaccine. These observations identify the critical immunological factors influencing vaccine efficacy following natural transmission of Leishmania

Middle East - North Africa and the millennium development goals : implications for German development cooperation

          Closed-loop controlled combustion is a promising technique to improve the overall performance of internal combustion engines and Diesel engines in particular. In order for this technique to be implemented some form of feedback from the combustion process is required. The feedback signal is processed and from it combustionrelated parameters are computed. These parameters are then fed to a control process which drives a series of outputs (e.g. injection timing in Diesel engines) to control their values. This paper’s focus lies on the processing and computation that is needed on the feedback signal before this is ready to be fed to the control process as well as on the electronics necessary to support it. A number of feedback alternatives are briefly discussed and for one of them, the in-cylinder pressure sensor, the CA50 (crank angle in which the integrated heat release curve reaches its 50% value) and the IMEP (Indicated Mean Effective Pressure) are identified as two potential control variables. The hardware architecture of a system capable of calculating both of them on-line is proposed and necessary feasibility size and speed considerations are made by implementing critical blocks in VHDL targeting a flash-based Actel ProASIC3 automotive-grade FPGA

Formal and Informal Politics from an Institutional Perspective: An Analytical Approach for Comparative Area Studies

In diesem Papier wird das sozialwissenschaftliche Analysefeld formaler und informeller Politik ausgeleuchtet und mit einer institutionellen Perspektive verknüpft. Dazu wird zunächst die bisherige Auseinandersetzung mit diesen beiden Formen der Politik im Rahmen der vergleichenden Politikwissenschaft und der Area Studies skizziert. Daran anknüpfend wird ein eigener konzeptioneller Zugang zum Thema präsentiert. Formale und informelle Elemente der Politik werden im Weiteren aus einem institutionellem Blickwinkel betrachtet. In diesem Kontext wird auch das Verhältnis formaler und informeller Institutionen im politischen Bereich diskutiert, wobei mögliche Vor- und Nachteile, Konsequenzen und Wirkungen beider Arten von Institutionen thematisiert werden. Perspektiven der weiteren Forschung beschließen das Papier.Formal and informal politics from an institutional perspective: An analytical approach for comparative area studies Formal and informal politics as an object of social science analysis are connected in this paper with an institutional perspective. First, we survey the existing comparatively oriented political science and area studies literature on both forms of politics. Second, we present our own conceptual approach in this regard. In the remainder of the paper, formal and informal politics are viewed through an institutional prism. In this context we discuss the relationship between formal and informal institutions in politics, looking at advantages and disadvantages, consequences, and effects of both types of institutions. Research perspectives are highlighted in the concluding section of the paper