Hop on the bus, Gus: the power of public transit

As a society, we have designed a transportation system that appears to work quite well for most of us; all we have to do is hop into a car and we are going places! Unfortunately, that system doesn’t work for all of us. The barrier to participation is really quite high. One must be able to afford a car, to maintain a car, and to insure a car and one must be able to drive - otherwise the system doesn’t offer much. In order to receive at least some benefit, access by the non-driver must be facilitated. Access facilitation to the transportation system is most often referred to as public transit. You may know it as the school bus or senior transportation. You may know it as the subway or the Wildcat transit bus

Long Term Sales Forecasts of Innovations - An Empirical Study of the Consumer Electronic Market

This paper empirically examines models of replacement sales for six electronic consumer durables – TVs, VCRs, DVD players, Digital Cameras, personal and notebook computers – using data from a large survey of 8077 German households. A new replacement model is developed that fits the empirical "lifetables" better than existing models. This said, fitting to replacement sales data was not substantially improved as these fits are not particularly sensitive to mis-specification of the shape of the underlying distribution. Since many product innovations can be targeted at replacement rather than first purchase buyers – this improved understanding of replacement behaviour helps entrepreneurs identify new opportunities

Investigating the role of hydrogen sulfide in the survival, growth and angiogenic potential of clear cell renal cell carcinoma cell lines and xenografts

Clear cell renal cell carcinoma (ccRCC) is characterized by Von Hippel-Lindau (VHL)-deficiency, resulting in pseudohypoxic, angiogenic and glycolytic tumours. Hydrogen sulfide (H2S) is an endogenously-produced gasotransmitter that accumulates under hypoxia and has been shown to be pro-angiogenic and cytoprotective in cancer. It was hypothesized that H2S levels are elevated in VHL-deficient ccRCC, contributing to survival, metabolism, and angiogenesis. Using H2S-specific probes, it was found that H2S levels were higher in VHL-deficient ccRCC cell lines compared to cells with wild-type VHL. Inhibition of H2S-producing enzymes could reduce the proliferation, metabolism and survival of ccRCC cell lines, as determined by live-cell imaging, XTT/ATP assay, and flow cytometry, respectively. Using the chorioallantoic membrane angiogenesis model, it was found that systemic inhibition of endogenous H2S production was able to decrease vascularization of VHL-deficient ccRCC xenografts. Endogenous H2S production is an attractive new target in ccRCC due to its involvement in multiple aspects of disease

Better together? Heterogeneous effects of tracking on student achievement

I study the effects of early between-school ability tracking on student achievement, exploiting institutional differences between German federal states. In all states, about 40% of students transition to separate academic-track schools after comprehensive primary school. Depending on the state, the remaining student body is either directly tracked between two additional school types or taught comprehensively for another two years. Comparing these students before and after tracking in a tripledifferences framework, I find evidence for positive effects of prolonged comprehensive schooling on mathematics and reading scores. These are almost entirely driven by low-achievers. Early and rigid forms of tracking can thus impair both equity and efficiency of school systems