Classroom Interventions for Reducing Public Speaking Anxiety

Findings of many studies demonstrate that instructors are able to offer instructional interventions that mediate state anxiety. The present study therefore examined several additional interventions designed to moderate situational factors contributing to state anxiety. The interventions were tested by creating cover stories similar to the Booth-Butterfield (1988a) study that described various instructional formats through which the first required speech in the introductory public speaking course would be processed. Respondents did not participate in actual in-class manipulations but were instructed to rate their perceived state anxiety if their first speech was structured in the manner described within each cover story. The primary purpose of the study was to generate a list of interventions that instructors may incorporate in the classroom with confidence. Support for perceptual responses will eventually require that manipulations actually be performed within the classroom. However, an extremely large number of interventions could be tested for in-class treatment. Thus, the process of selecting interventions may best be served by first narrowing the list to those that have been found to affect anxiety levels

Functional Characteristics of a Highly Specific Integrase Encoded by an LTR-Retrotransposon

Background: The retroviral Integrase protein catalyzes the insertion of linear viral DNA into host cell DNA. Although different retroviruses have been shown to target distinctive chromosomal regions, few of them display a site-specific integration. ZAM, a retroelement from Drosophila melanogaster very similar in structure and replication cycle to mammalian retroviruses is highly site-specific. Indeed, ZAM copies target the genomic 59-CGCGCg-39 consensus-sequences. To enlighten the determinants of this high integration specificity, we investigated the functional properties of its integrase protein denoted ZAM-IN. Principal Findings: Here we show that ZAM-IN displays the property to nick DNA molecules in vitro. This endonuclease activity targets specific sequences that are present in a 388 bp fragment taken from the white locus and known to be a genomic ZAM integration site in vivo. Furthermore, ZAM-IN displays the unusual property to directly bind specific genomic DNA sequences. Two specific and independent sites are recognized within the 388 bp fragment of the white locus: the CGCGCg sequence and a closely apposed site different in sequence. Conclusion: This study strongly argues that the intrinsic properties of ZAM-IN, ie its binding properties and its endonuclease activity, play an important part in ZAM integration specificity. Its ability to select two binding sites and to nick the DNA molecule reminds the strategy used by some site-specific recombination enzymes and forms the basis for site-specifi