An Examination of the Potential Impact of Multi-Use Trails on Housing Prices and Gentrification

The construction of green spaces in urban areas has shown to bring value to nearby properties. As this theory has held true for several multi-use trails constructed in cities in the United States, this paper uses the Champlain Canalway Trail, a multi-use trail in northeastern New York, as a case study to examine if housing prices respond similarly to the construction of multi-use trails in suburban and rural areas. Furthermore, this paper is used to test if theories of green gentrification also hold true outside of urban areas. A total of 8,619 house transactions conducted between 2005 to 2019 are used to conduct a spatial and difference-in-differences analysis to examine the effect of the construction and distance from the multi-use trail on the sales price of homes. The results of my research contradict previous green space theories and suggest that the construction of multi-use trails in suburban and rural areas can trigger a 17% decrease in the sales prices of houses within a half-mile from the trail, relative to the sales prices of houses two or more miles away. The results of this paper indicate that multi-use trails are unlikely to put urban and rural areas at risk of green gentrification

pKa Determination of a Histidine Residue in a Short Peptide Using Raman Spectroscopy

Determining the pKa of key functional groups is critical to understanding the pH-dependent behavior of biological proteins and peptide-based biomaterials. Traditionally, ¹H NMR spectroscopy has been used to determine the pKa of amino acids; however, for larger molecules and aggregating systems, this method can be practically impossible. Previous studies concluded that the C-D stretches in Raman are a useful alternative for determining the pKa of histidine residues. In this study, we report on the Raman application of the C2-D probe on histidine's imidazole side chain to determining the pKa of histidine in a short peptide sequence. The pKa of the tripeptide was found via difference Raman spectroscopy to be 6.82, and this value was independently confirmed via ¹H NMR spectroscopy on the same peptide. The C2-D probe was also compared to other Raman reporters of the protonation state of histidine and was determined to be more sensitive and reliable than other protonation-dependent signals. The C2-D Raman probe expands the tool box available to chemists interested in directly interrogating the pKa's of histidine-containing peptide and protein systems

Deuterium-Enhanced Raman Spectroscopy for Histidine pKa Determination in a pH-Responsive Hydrogel

We report here a method for the determination of the pKa of histidine in complex or heterogeneous systems amenable to neither solid-state nor solution NMR spectroscopy. Careful synthesis of a fluorenylmethyloxycarbonyl- and trityl-protected, C2-deuterated histidine produces a vibrational-probe-equipped amino acid that can readily be incorporated into any peptide accessible by standard solid-phase methods. The frequency of the unique, Raman-active stretching vibration of this C2-D probe is a clear reporter of the protonation state of histidine. We investigate here a pH-sensitive peptide that self-assembles to form a hydrogel at neutral pH. The pKa of the lone histidine residue in the peptide, which is likely responsible for this pH-dependent behavior, cannot be investigated by NMR spectroscopy because of the supramolecular, soft nature of the gel. However, after synthesizing a C2-deuterated-histidine-containing peptide, we were able to follow the protonation state of histidine throughout a pH titration using Raman difference spectroscopy, thereby precisely determining the pKa of interest