Urban transportation externalities are a key development challenge. Based on the existing literature, the authors illustrate the magnitudes of various external costs, review response policies, and measure and discuss their selection, particularly focusing on the context of developing countries. They find that regulatory policy instruments aimed at reducing local air pollution have been introduc...

In studying congestion tolling, it is important to account for heterogeneity in preferences of drivers, as ignoring it can bias the welfare gains. We analyse the effects of tolling, in the bottleneck model, with continuous heterogeneity in the value of time and schedule delay. The welfare gain of a time-variant toll increases with heterogeneity in the value of schedule delay. With heterogeneity...

The adhesion interaction between the immunoglobulin superfamily molecules CD2 and CD58 (lymphocyte function-associated antigen 3) plays an important role in T cell and natural killer cell interaction with various antigen-presenting and target cells. Determination of the solution structure of rat CD2 domain 1 has allowed a model of human CD2 domain 1 to be generated, and a series of mutants base...

In prokaryotes, disulfides are generated by the DsbA-DsbB system. DsbB functions to generate disulfides by quinone reduction. These disulfides are passed to the DsbA protein and then to folding proteins. To investigate the DsbA-DsbB catalytic system, we performed an in vivo selection for chromosomal dsbA and dsbB mutants. We rediscovered many residues previously shown to be important for the ac...

We consider an implementation problem faced by a planner who manages a roadway network. The problem entails both hidden information and hidden actions. We solve the planner's problem by introducing a new class of mechanisms and a new notion of implementation. The mechanisms, called price schemes, attach transfers to the available routes; they do not involve direct revelation. The method of impl...

European national policies involve a range of support measures to enhance the competitiveness of certain regions or products, inlcuding financial and institutional instruments. Some of these support measures involve environmentally counterproductive impacts. The question that rises in importance on the international agenda is how to reform these support measures, such that the original objectiv...

Nonhomologous end joining (NHEJ) in yeast depends on eight different proteins in at least three different functional complexes: Yku70-Yku80 (Ku), Dnl4-Lif1-Nej1 (DNA ligase IV), and Mre11-Rad50-Xrs2 (MRX). Interactions between these complexes at DNA double-strand breaks (DSBs) are poorly understood but critical for the completion of repair. We previously identified two such contacts that are re...

According to the World Health Organization, more than one million road traffic deaths occur every year throughout the world. In order to cope with this challenge, many countries have established quantified road safety targets backed up with comprehensive safety strategies. Road safety targets need to be based on reliable forecasting methods. Following the pioneering work by Elvik (2010), this p...

BACKGROUND Blood transfusions (BTFs) are not without risk and pose a significant financial burden on resource-limited services. In line with current international evidence, the nursery at Groote Schuur Hospital (GSH), Cape Town, South Africa, introduced a restrictive BTF protocol to minimise transfusions and manage costs. OBJECTIVE To determine whether adopting a restrictive BTF policy result...

Hepatitis C virus (HCV) is a worldwide health problem with high morbidity and mortality. HCV polymerase is an attractive target for the development of antiviral strategies. The aim of the present study was to report the sequence variation in the HCV NS5B gene from genotype 3 patient samples. The gene was amplified, cloned and sequenced. A nucleotide and amino acid sequence comparison of conserv...