Power to the people: using learner control to improve trainee reactions and learning in web-based instructional environments.

This experimental study investigated the mechanisms by which learner control influences learning in an e-learning environment. The authors hypothesized that learner control would enhance learning indirectly through its effect on trainee reactions and learner engagement (in particular, off-task attention), such that learners who were more satisfied with the training and devoted more cognitive resources toward the instructional content versus off-task thoughts would possess greater posttraining knowledge. The study also examined the role of individual differences (training motivation and goal orientation) in the prediction of these 2 mediating variables. A sample of 274 undergraduates completed an e-learning program, either with or without interactive, learner control tools. Results suggest that both training satisfaction and off-task attention predicted subsequent learning. Learner control had a positive impact on training satisfaction but was not related to off-task attention. The individual difference variables had a differential impact on the mediating variables. In particular, performance orientation was linked to off-task attention, whereas mastery orientation was found to indirectly influence satisfaction via its direct effect on training motivation. Implications for the design and further study of e-learning are discussed.

Five-year surveillance of West Nile and eastern equine encephalitis viruses in Southeastern Virginia.

To investigate the occurrence of West Nile virus (WNV) and Eastern equine encephalitis virus (EEE) in southeastern Virginia, the Bureau of Laboratories at the Norfolk Department of Public Health (NDPH) analyzed mosquito pools and the sera of sentinel chickens from the southeastern Virginia area each year from 2000 to 2004. Mosquito pool supernatants were screened for the presence of viral RNA by conventional reverse transcription polymerase chain reaction (RT-PCR) and Taqman RT-PCR with the i-Cycler. Mosquito pools were also tested for virus activity by Vero cell culture. The primary enzootic vector of WNV was Culex (Cx.) pipiens and that of EEE was Culiseta (Cs.) melanura. During the five-year surveillance period, the peak minimum infection rates (MIRs) of WNV and EEE in these mosquito species were 2.7 (2002) and 0.9 (2001), respectively. In 2003, the MIRs in Cs. melanura for WNV and EEE were 0.24 and 0.56, respectively; and the MIR for WNV in Cx. pipiens was 0.64. In 2004, Cs. melanura was less active in the WNV transmission cycle (MIR = 0.07) than was Cx. pipiens (MIR = 1.8), and Cs. melanura was the only vector for EEE (MIR = 0.37). The trend was for EEE activity to peak in July; WNV activity peaked in August. Sentinel-chicken sera were tested for IgM antibodies, and peak IgM seroconversions to these arboviruses were recorded in August 2003 for WNV and in July 2003 for EEE. In 2004, the highest IgM seroconversions to EEE occurred later in August. The overall trend of arbovirus activity was greater in 2003 than in 2004.