Discovery of new mutually orthogonal bioorthogonal cycloaddition pairs through computational screening.

Density functional theory (DFT) calculations and experiments in tandem led to discoveries of new reactivities and selectivities involving bioorthogonal sydnone cycloadditions. Dibenzocyclooctyne derivatives (DIBAC and BARAC) were identified to be especially reactive dipolarophiles, which undergo the (3+2) cycloadditions with N-phenyl sydnone with the rate constant of up to 1.46 M-1 s-1. Most signifcantly, the sydnone-dibenzocyclooctyne and norbornene-tetrazine cycloadditions were predicted to be mutually orthogonal. This was validated experimentally and used for highly selective fluorescence labeling of two proteins simultaneously

Do People’s Perceptions of Neighborhood Bikeability Match “Reality”?

Do people perceive the built environment the same as we objectively measure it? If not, what are the relative roles of the objective versus the perceived environment on bicycling behavior? This study, based on data from Portland, Oregon, explored the match or mismatch between the objective and perceived bicycling environment and how it affects people’s bicycling behavior. The descriptive analysis indicated a fair agreement between perceived and objective measures. Older adults, women having children, less-educated and lower-income persons, and those who bicycle less tended to perceive their high-bikeable environment (measured objectively) as being a low-bikeable environment. In addition to the socio-demographics, this study also found that the social environment can play a role in the relationship between the objective and perceived environment. Finally, results of this study indicated that both the actual and perceived built environment are associated with bicycling behavior, particularly for utilitarian bicycling. For recreational bicycling, the objective environment attributes measured in this study are not significant factors, while perceptions do matte

Transport Disadvantage, Social Exclusion and Subjective Wellbeing: The Role of Built Environment – Evidence from Sydney, Australia

This study explores the effects of the built environment on transport disadvantage, social exclusion, personal health and subjective wellbeing (SWB) using survey data collected in four socio-economically disadvantaged neighbourhoods in Sydney, Australia. The data is analysed at both neighbourhood and individual levels using both descriptive analysis and structural equation modelling (SEM). Overall, our model supports the hypothesis that a walkable neighbourhood environment, measured by density, diversity, access, and infrastructure for walking and cycling, helps to reduce transport disadvantage and increase social inclusion. However, the impact of the physical environment does not carry forward to impact personal health and SWB. The exception to this finding is where the environment is perceived to be aesthetically pleasing – a variable which significantly positively affects SWB. In addition to the physical environment, crime is a significant factor that directly influences transport disadvantage and SWB

Experimental study of flashing LNG jet fires following horizontal releases

A horizontally oriented jet fire could occur if the leaking liquefied natural gas (LNG) from the side surface of a pipe or storage tank was ignited. Previous work with LNG mostly focused on pool fires. In the present study, horizontally oriented LNG jet fires were studied through 10 open field full scale tests. The flames were visualized by both infrared and video cameras. The recorded flame shapes are compared and analysed. Peak temperatures and heat fluxes at various flow rates were measured and recorded. For relatively low reservoir pressure, a small amount of LNG was found to spray through the fire and rainout onto the ground, forming an LNG pool. A correlation was established to calculate the flame length from the mass flow rate

Inspirational Teacher of the Life Science Award Seminar: "If I had known I was going to live this long, I would have taken better care of myself" - Mickey Mantle (2015-04-03)

The Inspirational Teacher of the Life Science Award Seminar 2015Award presentationUMD Biology DepartmentDepartment of Biolog