Publications by authors named "D Woolard"

Objectives: The Virginia Department of Health (VDH) identified an outbreak of serotype Javiana infections in Virginia after a chili and chowder cook-off with 11 competitors and about 2500 attendees on September 30, 2017. The objectives of this study were to assess the extent of the outbreak and identify the most likely source of exposure.

Methods: To identify people with suspected infection, VDH used press releases and social media posts to recruit event attendees to take an online survey about foods eaten at the cook-off and any gastrointestinal (GI) symptoms experienced.

View Article and Find Full Text PDF

Context: The potential for hepatitis B and C virus (HBV/HCV) transmission in nail salons and barbershops has been reported, but a systematic review has not been conducted. These businesses are regulated by state cosmetology or barbering boards, but adequacy of sanitary requirements has not been evaluated.

Objectives: To conduct literature review to assess risk for HBV/HCV transmission in nail salons and barbershops and to evaluate sanitary requirements in HBV/HCV prevention in these businesses in 50 states and District of Columbia.

View Article and Find Full Text PDF

Terahertz (THz) absorption of biotin was simulated using the first principle and the density functional theory (DFT) both in the harmonic approximation and with corrections for the anharmonicity. Anharmonicity corrections were calculated using two different approaches. First, the perturbation theory-based first principle calculations were performed to include third- and fourth-order anharmonicity corrections in atomic displacements to harmonic vibrational states.

View Article and Find Full Text PDF

In this work, the biotin-streptavidin complex was studied with density functional theory (DFT), molecular mechanical methods (MM), and a hybrid DFT/MM approach in order to obtain the theoretical predictions for electronic structures, binding, optical transitions, harmonic vibrations, and absorption spectra. It was demonstrated that biotin solvation in water can reduce the binding strength to streptavidin by more than half. All studied properties, including the biotin binding and the UV absorption of the biotin-streptavidin complex, are predicted to be protonation state dependent.

View Article and Find Full Text PDF

In any automated algorithm for interpreting photoelastic fringe patterns it is necessary to understand and quantify sources of error in the measurement system. We have been considering how the various components of the coating affect the photoelastic measurement, because this source of error has received fairly little attention in the literature. Because the reflective backing is not a perfect retroreflector, it does not preserve the polarization of light and thereby introduces noise into the measurement that depends on the angle of obliqueness and roughness of the reflective surface.

View Article and Find Full Text PDF