Effect of extrinsic incubation temperature on borrelial infection in various organs of Ornithodoros (O.

Effects of three extrinsic incubation (EI) temperatures on vector competence of Ornithodoros savignyi to Borrelia sp. isolated from a natural population of the tick in Egypt were investigated. The EI temperature influenced the efficiency of Borrelia sp. transmission by the female O. savignyi to hamsters. An EI temperature for 27 o C was optimum for successful transmission of Borrelia sp. where the highest infection rates (IRs) in hamsters occurred. Generally, the IRs in hamsters decreased by lowering the EI temperature to 17 o C or rising it to 37 o C in each of the corresponding experimental cases (number and postinfection period of the tick feeding per hamster) tested. Ornithodoros savignyi kept at 27 o C and 37 o C maintained borrelial infection transstadially from nymph 1 to 7 and adults. The transstadially infected stages transmitted the spirochetes to hamsters with higher IRs at 27 o C than 37 o C. Transovarial transmission of Borrelia sp. occurred during the first and second (at higher rates) gonadotrophic cycle in the infected female ticks kept at 27 o C and 37 o C. However, no molting or oviposition occurred at 17 o C.

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The trend of development of gyroscopes used in Inertial Navigation and Guidance systems, led to the adaptation of vibrating gyros to fulfil the basic requirements on such systems specially for military applications in aircraft and guided missiles. The oscillogyro is a new type of vibrating gyroscopes suitable for stabilizing inertial platforms. It is characterized by its simplicity, reliability and low cost of production. In this work, the application of oscillogyro in inertial navigation systems (INS) is introduced. After a short description of the oscillogyro as a two axes rate or displacement gyro, the mass-unbalance error is analyzed. The propagation of such error into an INS with single-axis vertical indicating platform, is investigated. The results of analysis show quite satisfactory performance and promising future for the application of oscillogyro in a wide range of INS and guidance systems.