2 resultados para internet data centers
em Brock University, Canada
Resumo:
Preadolescent Internet usage is prevalent today. This thesis examined how Canadian preadolescents use the Internet, what they do when they are on the Internet, and why preadolescents are fascinated with the Internet. Eight quahtative categories were derived from the data. The categories are Downloading, Information Hunting, Consumerism, Virtual Nurturing, Gaming, Expressions of Violence, Chatting, and Music. By critically distilling and analyzing preadolescent Internet behaviour through the lens of behavioural and cognitive psychology, and explicating the amount of psychological, cognitive, and social learning that preadolescents may be exposed to on the Internet, and the attraction that is cumulatively a profound draw for a preadolescent audience, an argument will be made that Internet usage in preadolescents may impair their cognitive, social, and psychological development because of the impulse seeking and gratification priming that has been reinforced during the formative period of preadolescence.
Resumo:
Two time-resolved EPR techniques, have been used to study the light induced electron transfer(ET) in Type I photosynthetic reaction centers(RCs). First, pulsed EPR was used to compare PsaA-M688H and PsaB-M668H mutants of Chlamydomonas reinhardtii and Synechosystis sp. PCC 6803.The out-of-phase echo modulation curves combined with other EPR and optical data show that the effect of the mutations is species dependent. Second, transient and pulsed EPR data are presented which show that PsaA-A660N and PsaB-A640N mutations in C. reinhardtii alter the relative quantum yield of ET in the A- and B-branches of PS I. Third, transient EPR studies on RCs from Heliobacillus mobilis that have been exposed to oxygen show partial inhibition of ET. In the RCs in which ET still occurs, the ET kinetics and EPR spectra show evidence of oxidation of some but not all of the, BChl g and BChl g' to Chl a.