Lytic activity by temperate phages of Pseudomonas aeruginosa in long-term cystic fibrosis chronic lung infections

Pseudomonas aeruginosa is the most common bacterial pathogen infecting the lungs of cystic fibrosis (CF) patients. The transmissible Liverpool epidemic strain (LES) harbours multiple inducible prophages (LESϕ2; LESϕ3; LESϕ4; LESϕ5; and LESϕ6), some of which are known to confer a competitive advantage in an in vivo rat model of chronic lung infection. We used quantitative PCR (Q-PCR) to measure the density and dynamics of all five LES phages in the sputa of 10 LES-infected CF patients over a period of 2 years. In all patients, the densities of free-LES phages were positively correlated with the densities of P. aeruginosa, and total free-phage densities consistently exceeded bacterial host densities 10–100-fold. Further, we observed a negative correlation between the phage-to-bacterium ratio and bacterial density, suggesting a role for lysis by temperate phages in regulation of the bacterial population densities. In 9/10 patients, LESϕ2 and LESϕ4 were the most abundant free phages, which reflects the differential in vitro induction properties of the phages. These data indicate that temperate phages of P. aeruginosa retain lytic activity after prolonged periods of chronic infection in the CF lung, and suggest that temperate phage lysis may contribute to regulation of P. aeruginosa density in vivo

Computerized decision aid for first-time homebuyers

Technology-mediated assistance in house purchasing decision is evidenced in many developed countries, however, in Malaysia less study was found although the decision challenges faced by first-time homebuyers are undeniable. This study attempts to embed technology assistance in the prominent consumer decision-making process model for the purpose of assisting first time homebuyers to make a house purchasing decision. This study employs mixed method approaches with Klang Valley, Malaysia as case study. 19 housing attributes under Locational, Neighborhood, Structural and Social Cultural group, are surveyed to validate the distinctive nature of the attributes to be part of the decision-making criteria. Factor analysis is performed on 320 data from the potential first-time homebuyers in Klang Valley. Two key factors are confirmed from the analysis; which are needs (i.e. Locational and Structural) and preferences (i.e. Neighborhood and Social Cultural). Both factors are later embedded in the proposed design model of computerized decision aid for homebuyers. The model is then evaluated through expert reviews and data was analysed qualitatively using thematic analysis. Four themes emerged from the analysis, which are Suggestion, Concern, Strength, and Limitation. Meaningful discovery on how would the future applications may have an impact is made through analysing themes with negative connotation like Concern and Limitation. The focused themes also reflect actual insights from the industry’s key players, which are useful for improvement of the proposed design model and towards more effective computerized decisionaid for first-time homebuyers