Are Health Insurance Premiums Higher for Small Firms?

Reviews research on how health insurance costs differ between small and large firms, how firm size affects administrative costs and offer rates, and how state mandates, purchase pools, and other factors affect overall costs. Considers policy implications

Novel particulate vaccine candidates recombinantly produced by pathogenic and nonpathogenic bacterial hosts : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Microbiology at Massey University, Manawatu, New Zealand.

Polyhydroxyalkanoates (PHAs) are biopolyesters synthesized as small spherical cytoplasmic inclusion bodies by a range of bacteria. Recently, PHA beads have been investigated for use as a vaccine delivery platform by using engineered heterologous production hosts that allowed the efficient display of vaccine candidate antigens on the beads surface and were found to greatly improve immunogenicity of the displayed antigens. However, like other subunit vaccines, these antigen-displaying (vaccine) PHA beads only provide a limited repertoire of antigens. In this thesis we investigate the idea of directly utilizing the disease causative pathogen or model organism to produce vaccine PHA beads with a large antigenic repertoire. These beads are hypothesized to have the potential to induce greater protective immunity compared to production of the same PHA bead in a heterologous production host. This concept was exemplified with Pseudomonas aeruginosa and Mycobacterium tuberculosis as model human pathogens. For P. aeruginosa we describe the engineering of this bacterium to promote PHA and Psl (polysaccharide) production. This represents a new mode of functional display for the engineering, production, and validation of a novel OprI/F-AlgE fusion antigen-displayed on PHA beads. For the disease tuberculosis we investigated the use of nonpathogenic M. smegmatis as a model organism for M. tuberculosis. We described the bioengineering, production, and validation of Ag85AESAT- 6 displayed on PHA beads produced in M. smegmatis. Here we showed that both organisms were harnessed to produce custom-made PHA beads for use as particulate subunit vaccines that carried copurifying pathogen-derived proteins as a large antigenic repertoire and the ability of these vaccine PHA beads to generate a protective immune response. This novel bioengineering concept of particulate subunit vaccine production could be applied to a range of pathogens naturally producing PHA inclusions for developing efficacious subunit vaccines for infectious diseases

Thick metric spaces, relative hyperbolicity, and quasi-isometric rigidity

We study the geometry of nonrelatively hyperbolic groups. Generalizing a result of Schwartz, any quasi-isometric image of a non-relatively hyperbolic space in a relatively hyperbolic space is contained in a bounded neighborhood of a single peripheral subgroup. This implies that a group being relatively hyperbolic with nonrelatively hyperbolic peripheral subgroups is a quasi-isometry invariant. As an application, Artin groups are relatively hyperbolic if and only if freely decomposable. We also introduce a new quasi-isometry invariant of metric spaces called metrically thick, which is sufficient for a metric space to be nonhyperbolic relative to any nontrivial collection of subsets. Thick finitely generated groups include: mapping class groups of most surfaces; outer automorphism groups of most free groups; certain Artin groups; and others. Nonuniform lattices in higher rank semisimple Lie groups are thick and hence nonrelatively hyperbolic, in contrast with rank one which provided the motivating examples of relatively hyperbolic groups. Mapping class groups are the first examples of nonrelatively hyperbolic groups having cut points in any asymptotic cone, resolving several questions of Drutu and Sapir about the structure of relatively hyperbolic groups. Outside of group theory, Teichmuller spaces for surfaces of sufficiently large complexity are thick with respect to the Weil-Peterson metric, in contrast with Brock--Farb's hyperbolicity result in low complexity.Comment: To appear in Mathematische Annale