Architectural evolution in cocoons spun by Hyalophora (Lepidoptera; Saturniidae) silk moth species.

Caterpillars of the silk moth genus Hyalophora (Lepidoptera; Saturniidae) construct multilayered cocoons that function as overwintering housing during the pupal to adult developmental period. While all cocoons share the primary function of protecting the developing moth, cocoons spun by different Hyalophora silk moth species vary significantly in architectural features and in the level of intraspecific cocoon-type polymorphism. We compared the cocoons of Hyalophora species found throughout North America and investigated the evolution of architectural variation. We first characterized and compared the architectural features of cocoons at all three cocoon sections (outer envelope, inner envelope, and the intermediate section that separates them), and found that variation in the outer envelope underlies the differences in architecture between cocoons. Phylogenetic analysis indicates ancestral polymorphic architecture (both "baggy" and "compact" morphs), with diversification within Hyalophora for both monomorphic "compact" cocoons, and increased intermediate space and silk in "baggy" lineages. The evolution of these traits suggests a potential functional role for the different cocoon architectural forms.

Effects of an undergraduate HIV/AIDS course on students' HIV risk.

This study utilizes a quasi-experimental pre- and post-test survey design to examine the effects of a course, called HIV/AIDS: Science, Behavior, and Society, on undergraduate students' HIV knowledge, attitudes and risky sexual behaviors. With the assistance of social work faculty the course incorporates experiential learning pedagogy and a transdisciplinary perspective. Although the course was not designed as a prevention program, the theory of health behavior suggests the incorporation of experiential learning will impact crucial HIV/AIDS attitudes and behaviors. When regression models were applied, relative to the comparison group (N = 111), the HIV/AIDS class students (N = 79) reported an increase in post-test HIV knowledge, perceived susceptibility to HIV among females, and a reduction of risky sexual attitudes among sexually active students.