In mature male snakes and lizards, a distal portion of the nephron is hypertrophied in relation to its appearance in females and immature males. This sexual segment of the male kidney apparently provides seminal fluid that is mixed with sperm and released into the female cloaca during copulation. In this article, we provide the first study at the ultrastructural level of seasonal variation in the sexual segment of the kidney of a squamate, the natricine snake Seminatrix pygaea. Previous workers have indicated that the sexual segment is secretory only when the testes are spermatogenically active. The sexual segment of the kidney in S. pygaea does not go through an extended period of inactivity but does show a cycle of synthesis and secretion that can be related to the spermatogenic cycle and mating activity. We show that synthesis of secretory product is initiated with the onset of spermatogenic activity in the spring and culminates with completion of spermiation in the fall. Secretion of the product, however, occurs in a premating period in March when the testes are inactive. Secretion during this premating period is probably necessary to provide time for the passage of the products down the ureter in order to mix with sperm during mating later in spring.

Intense pulsed active detection (IPAD) has been proposed as a means of detecting contraband fissile material using an intense bremsstrahlung pulse to induce photofission. (S.B. Swanekamp, et al., IEEE Trans. Nucl. Sci. 58, 2011, pp. 2047 -2056 also see presentations at this conference by B.V. Weber, et al., S.B. Swanekamp, et al., and J.C. Zier, et al.) A number of pulsed power technologies were evaluated for this application including the linear induction accelerator (LIA) and the linear transformer driver (LTD) before selecting the induction voltage adder (IVA) for further study, as described by I.D. Smith et al., also at this conference. An important factor for the IVA choice in this particular exercise is that research and development be minimized if there were to be a design and construction effort.For this design study, it was assumed that the IVA based IPAD driver should produce 6-mC of electrical charge at 12-MV. By shaping the inner conductor of the coaxial PFLs, the 50ns FWHM simulated electrical pulse in a constant 60-ohm diode produces a 30-ns flat top voltage with a current of 200-kA. The IVA hardware can also be configured to produce the same 200-kA, flat topped current pulse at 10-MV without changing the Marx charge level. The flat topped voltage pulse minimizes the IVA energy and physical size by exploiting the photofission's V 9 dependence for bremsstrahlung from electrons with endpoints between 8 and 12-MeV. (Swanekamp, op. cit.) Unlike existing IVAs with similar output power and energy, it is desired that this IVA be transportable and be able to be assembled with a minimum of time and effort. The IVA hardware resulting from this study comprises two separate units, one for the Marxes and the other for the PFLs and cavities. The largest unit is only 23-feet long and weighs less than 52-k lbs. Two additional units are required to transport the ancillaries and insulating oil. The IVA's physical size, weight, and cost were minimized through a configuration trade-off study that evaluated different output currents, Marx designs, and numbers of PFLs and induction cavities. Components were sized to be consistent with reliable performance at a nominal shot rate of one per minute. ________________________ *

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