Timing of Colonization of Caries-Producing Bacteria: An Approach Based on Studying Monozygotic Twin Pairs

Findings are presented from a prospective cohort study of timing of primary tooth emergence and timing of oral colonization of Streptococcus mutans (S. mutans) in Australian twins. The paper focuses on differences in colonization timing in genetically identical monozygotic (MZ) twins. Timing of tooth emergence was based on parental report. Colonization timing of S. mutans were established by plating samples of plaque and saliva on selective media at 3 monthly intervals and assessing colony morphology. In 25% of individuals colonization occurred prior to emergence of the first tooth. A significant proportion of MZ pairs (21%) was discordant for colonization occurring before or after first tooth emergence, suggesting a role of environmental or epigenetic factors in timing of tooth emergence, colonization by S. mutans, or both. These findings and further application of the MZ co-twin model should assist in development of strategies to prevent or delay infection with S. mutans in children

Design case of the E-19 AEOLUS supersonic business jet

This paper introduces the E-19 AEOLUS supersonic business jet designed by the authors (conceptual design) and a team of Staff and a team of graduate students (preliminary and detail design) from the Aerospace Vehicle Design MSc. The design is presented at the 50th anniversary of the first flight of Concorde and with growing interest from many aircraft design companies. An attractive design would still need the usual attributes of safety, security, comfort, reliability, performance and operational flexibility. This paper presents a design that attempts to address these issues. The details of cabin, structures, landing gear, systems, powerplants, etc. are designed. Low-boom low-drag technologies are applied to the design. The synthetic vision display and double drooping nose are introduced to increase the pilot’s field of view. The resulting concept is challenging but could result in an aircraft well suited to meet a new market opportunit

Conceptual design of low-boom low-drag supersonic transports

This paper introduces a supersonic aircraft design model developed in a multidisciplinary design analysis and optimization (MDAO) environment. Low- to medium- fidelity methods are applied to the conceptual design model. A family of different classes supersonic aircraft are designed with similar general layout, including a single seat supersonic demonstrator, a 10-passenger supersonic business jet and a 50-seat supersonic airliner. These concepts prove the feasibility of low-boom low-drag supersonic transport designs in a multidisciplinary perspective. There are some challenges to balance the volume with packaging and control requirements. The low-boom design for configuration with nacelles are also very challenging