Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s).Sarcocystis neurona is an apicomplexan parasite and the primary cause of equine protozoal myeloencephalitis (EPM). EPM is a serious debilitating disease and is the most commonly diagnosed neurologic disorder of horses. Although seroprevalence studies have indicated that approximately 30 to 50% of horses have been exposed to S. neurona, the incidence of EPM is estimated to be less than 1% (15, 46). Thus, S. neurona infection clearly does not equate directly with clinical illness, and it is not clear what factors influence the progression from simple infection to severe neurologic disease. The normal life cycle of S. neurona alternates between the definitive host, the opossum (20), and various small mammal intermediate hosts, including skunks (9), raccoons (17), armadillos (8), and cats (16). Although S. neurona readily infects equids, these animals are currently believed to be aberrant hosts for this parasite species since latent forms (sarcocysts) have not been found in infected horses.Like other members of the Apicomplexa, S. neurona is an obligate intracellular parasite that requires a number of unique molecules (i.e., virulence factors) to support its parasitic lifestyle. Apicomplexan surface molecules are important virulence factors that are responsible for the pathogen's initial interactions with the host cell surface and components of the host immune response. A broad family of more than 20 relate...

The lack of a comprehensive database for both concentrating and photovoltaic utility-scale solar power projects, those with a generation capacity of greater than 50 MW, hinders the ability of researchers and policy makers to examine the state of solar development in the state of California. This research project seeks to fill this gap in understanding by creating a database of proposed and developed projects in order to examine trends in proposals, process time, approvals, and construction starts. Existing literature was evaluated to determine potential factors for project success in approval and construction. Upon determination of these factors, the project database was developed through use of publicly available data and extensive Internet searches of planning documents, industry releases, and articles on existing and proposed projects. The completed database, containing eighty projects, was analyzed to provide an initial look at the overall state of solar project development in California. This report details these early findings as well as areas for further research. The analysis indicates that, while California has a high amount of proposed projects and generation capacity, many projects do not reach the end of the public approval process and fewer still enter construction and operation.