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There has been increased interest surrounding the use of tea tree oil (TTO) as a natural antimicrobial. In this study, the antimicrobial activity of TTO and its components were investigated in vitro and in a predominantly lipid-based personal care formulation. In vitro, TTO showed minimal inhibitory concentrations of 0.2% (for Saccharomyces cerevisiae and Pythium sulcatum), 0.4% (for Escherichia coli, Bacillus subtilis, and Rhizopus stolonifer), and 0.8% (for Botrytis cinerea). TTO at 0.08%-0.8% was often as efficient as parabens. Comparison of the antimicrobial activities of TTO components showed that terpinen-4-ol and γ-terpinene were generally most effective in inhibiting microbial growth. TTO activity in a personal care product was evaluated through air and water exposure, artificial inoculation, and shelf life studies. While TTO did not increase shelf life of unopened products, it decreased microbial load in products exposed to water and air. Results from this study support that antimicrobial activity of TTO can be attributed to varying levels of its components and that low levels of TTO were effective in reducing microbial growth during the use of the product. This study showed that TTO can act as a suitable preservative system within an oil-based formulation.

The spruce budworm is the most economically important destructive insect pest affecting North American forests. Some endophytes, isolated from the Acadian forest, produce secondary metabolites, toxic to the spruce budworm in planta. The aim of this study was to investigate the biologically active extracts of endophytes of red (Picea rubens) and black spruce (P. mariana). This was hypothesized to result in the isolation of antifungal and antiinsectan metabolites with structural similarities to related pathogenic toxins. From this investigation, 13 secondary metabolites were isolated. Three macrocyclic lactones (1-3) were characterized from Nectria dacryocarpa. Five aromatic polyketides (4-8) were isolated from two unique species of Penicillium cf. glaucoalbidum belonging to the Thysanophora sect. One small amino acid derived molecule, tyrosol (9) was isolated from the endophyitc P. cf. glaucoalbidum. Four lachnellulone related compounds (10-13) were isolated from Lachnellula cf. calyciformis including two new compounds (12, 13). Most purified secondary metabolites inhibited the growth of test microorganisms in vitro, including Saccharomyces cerevisiae, Bacillus subtilis, Escherichia coli, and Microbotryum violaceum.

This paper investigates the relationship between the financial positions of a subcontractor and their performance on the construction site. Financial default by a subcontractor can cost general contractors additional time and expense, as they try to find replacements and keep the projects on schedule. This highlights the importance of vetting subcontractors before awarding a bid. This study attempts to bridge the gap between the subjective nature of construction quality and the more technical financial analysis in determining the overall quality of subcontractors. Safety measures are also incorporated into performance ratings. Data is collected for the years 2009 through 2014 from JE Dunn Construction's private databases. A panel least squares regression is used to estimate subcontractor score. Results do not demonstrate any consistent relationship between financial health and performance quality, but do provide a foundation for further analysis and research.