Autosomal dominant polycystic kidney disease (ADPKD) strikes 1 in 1000 individuals and often results in end-stage renal failure. Mutations in either PKD1 or PKD2 account for 95% of all cases [1-3]. It has recently been demonstrated that polycystin-1 and polycystin-2 (encoded by PKD1 and PKD2, respectively) assemble to form a cation channel in vitro [4]. Here we determine that the Caenorhabditis elegans PKD1 and PKD2 homologs, lov-1 [5] and pkd-2, act in the same pathway in vivo. Mutations in either lov-1 or pkd-2 result in identical male sensory behavioral defects. Also, pkd-2;lov-1 double mutants are no more severe than either of the single mutants, indicating that lov-1 and pkd-2 act together. LOV-1::GFP and PKD-2::GFP are expressed in the same male-specific sensory neurons and are concentrated in cilia and cell bodies. Cytoplasmic, nonnuclear staining in cell bodies is punctate, suggesting that one pool of PKD-2 is localized to intracellular membranes while another is found in sensory cilia. In contrast to defects in the C. elegans autosomal recessive PKD gene osm-5 [6-8], the cilia of lov-1 and pkd-2 single mutants and of lov-1;pkd-2 double mutants are normal as judged by electron microscopy, demonstrating that lov-1 and pkd-2 are not required for ultrastructural development of male-specific sensory cilia.

A mechanism has been developed by which a three-dimensional Electron Cyclotron Resonance Heating (ECRH) ray-tracing-absorption calculation may be coupled to a tandem mirror transport code. The radial temperature and density profiles of the transport code are expanded via flux conservation to provide the three-dimensional geometry required for the ray-tracing calculation. Absorption along the ray trajectory determines an equivalent radial ECRH power deposition profile for use by the transport code. This profile must be generated by using multiple ray-tracing calculations to simulate the spatial spread of the power launched from an antenna. A technique for artificially producing these multiple ray simulations is presented and compared with results where multiple ray-tracing calculations were performed. Examples of plasma build-up simulations for a tandem mirror using ECRH in the plug are provided. A positive feedback mechanism is identified which produces locally large electron temperatures. This occurs frequently near the plasma edge, shielding the electrons near the plasma axis from the incident ECRH power, and producing a hollow temperature profile. This may lead to the collapse of the plug plasma.