Development of a fixative protocol using formaldehyde and gluteraldehyde for preservation of microbial art on agar plates.

Agar art bridges the gap between science and art, using microbes instead of paint. Afterwards, the art can change in response to microbial fluctuation, meaning preservation of the original art is essential. Here, formaldehyde and glutaraldehyde were investigated as preservatives, involving techniques used in healthcare settings to preserve samples. Formaldehyde was tested at 1.0%, 2.0% and 3.7%, w/v, whereas glutaraldehyde was tested at 1% and 2.5%, w/v. Both compounds and respective concentrations were tested for different time periods. Escherichia coli, Serratia marcescens, Staphlococcus aureus and Micrococcus luteus were used as bacteria for "drawing" the works of art. The effectiveness of fixation was determined using integrated densities and visual assessment. Initially, both compounds showed potential promise, albeit with a loss of bacteria. Ser. marcescens was prone to colour changes and glutaraldehyde caused discolouration of agar and bacteria. These could be caused by a pH decrease in the agar, due to residual free aldehyde groups. Reduction of this was tested using 300 mM sodium metabisulfite to neutralize excess aldehydes. This initially led to reduced bacterial loss and avoided colour changes, however measurements 24 h post-fixation showed colour loss to some bacterial clusters. This study found that, depending on the species, use of at least 2% formaldehyde for a short fixation period (typically 1 min) was the most promising approach for the preservation of art. Given the success of this with different bacteria, it would make a good starting combination for anyone trying to fix agar art; depending on the bacterial species used, methodology refinement may be needed for optimisation. This study shows successful fixation and preservation of different bacterial species on agar for the first time. The impact of this is to preserve agar art while making it safe and non-infective to those in contact with the microbial art

Herbert Hoover Elementary / Charleston Complete Corridor Plan

Completed as a part of CRP 425 bicycle and pedestrian planning, led by Dr. William Riggs, this planning project assessed the Herbert Hoover Elementary site and Charleston corridor in the City of Palo Alto with an aim to bring a complete streets strategy to the area. The plans recommend improved accessibility for bicycles and pedestrians along Charleston Road including modal separation between bicyclists and pedestians, improved vehicular flows to mitigate vehicular traffic congestion during peak hours and increased innovation in safety features to prevent pedestrian-vehicle conflicts