The Toxoplasma gondii plastid replication and repair enzyme complex, PREX

A plastid-like organelle, the apicoplast, is essential to the majority of medically and veterinary important apicomplexan protozoa including Toxoplasma gondii and Plasmodium. The apicoplast contains multiple copies of a 35 kb genome, the replication of which is dependent upon nuclear-encoded proteins that are imported into the organelle. In P. falciparum an unusual multi-functional gene, pfprex, was previously identified and inferred to encode a protein with DNA primase, DNA helicase and DNA polymerase activities. Herein, we report the presence of a prex orthologue in T. gondii. The protein is predicted to have a bi-partite apicoplast targeting sequence similar to that demonstrated on the PfPREX polypeptide, capable of delivering marker proteins to the apicoplast. Unlike the P. falciparum gene that is devoid of introns, the T. gondii prex gene carries 19 introns, which are spliced to produce a contiguous mRNA. Bacterial expression of the polymerase domain reveals the protein to be active. Consistent with the reported absence of a plastid in Cryptosporidium species, in silico analysis of their genomes failed to demonstrate an orthologue of prex. These studies indicate that prex is conserved across the plastid-bearing apicomplexans and may play an important role in the replication of the plastid genome

Impurity crystal in a Bose-Einstein condensate

We investigate the behavior of impurity fields immersed in a larger condensate field in 1, 2, and 3 dimensions. We discuss the localization of a single impurity field within a condensate and note the effects of surface energy. We derive the functional form of the attractive interaction between two impurities due to mediation from the condensate. Generalizing the analysis to $N$ impurity fields, we show that within various parameter regimes a crystal of impurity fields can form spontaneously in the condensate. Finally, the system of condensate and crystallized impurity structure is shown to have nonclassical rotational inertia, which is characteristic of superfluidity, i.e. the system can be seen to exhibit supersolid behavior.Comment: 5 pages, 3 color figures; Accepted to Phys. Rev. Let

Fabrication and wear test of a continuous fiber/particulate composite total surface hip replacement

Continuous fiber woven E-glass composite femoral shells having the ame elastic properties as bone were fabricated. The shells were then encrusted with filled epoxy wear resistant coatings and run dry against ultrahigh molecular weight polyethylene acetabular cups in 42,000 and 250,000 cycle were tests on a total hip simulator. The tribological characteristics of these shells atriculating with the acetabular cups are comparable to a vitallium bal articulating with an ultrahigh molecular weight polyethylene cup

Improving water utilization from a catchment perspective

Water management / Water scarcity / Water use efficiency / Catchment areas / Calibrations / Hydrology / Models / River basins / Participatory management / Water balance / Case studies / Asia / Africa / South Africa / Zimbabwe

Tribological characteristics of a composite total-surface hip replacement

Continuous fiber, woven E glass composite femoral shells having the same elastic properties as bone were fabricated. The shells were then encrusted with filled epoxy wear resistant coatings and run dry against ultrahigh molecular weight polyethylene acetabular cups in 42,000 and 250,000 cycle wear tests on a total hip simulator. The tribological characteristics of these continuous fiber particulate composite femoral shells articulating with ultrahigh molecular weight polyethylene acetabular cups were comparable to those of a vitallium ball articulating with an ultrahigh molecular weight polyethylene acetabular cup

Economic Feasibility of Kenaf Production in Three Tennessee Counties

Since the 1940s, kenaf has been viewed as a potential source of fiber, mainly for newsprint and high quality paper. Kenaf research has once again risen to the forefront due to the recent USDA tobacco buyout. Many states and farmers dependent upon tobacco revenues have been seeking alternative crops for a number of years. This study seeks to expand the current literature by examining the economic feasibility of growing kenaf within three counties in Tennessee. Nitrogen meta-yield response functions for kenaf and four traditional crops were developed for 30 soils through crop growth simulation modeling and used to compare optimal crop budgets for each soil. Results reveal that kenaf would not compete favorably with traditional crops on any soil at prices below $49/ton, while profit-maximizing farmers could supply as much as 1,385,700 tons of kenaf if the price were$55/ton.alternative crop, economic feasibility, enterprise budgeting, kenaf, plant growth modeling, yield response functions, Agribusiness, Crop Production/Industries,