A Railway Wheel Wear Prediction Tool based on a Multibody Software

The wheel wear prediction is a key-topic in the field of railway research as it has big impact on economical and safety aspects of trainset design, operation and maintenance. The aim of this work was to implement a flexible and pre-dictive railway wheel wear tool that, starting from a specific vehicle mission, provides the wheel profile evolution as a function of the distance run. The we-ar estimation tool consists of the use of a sequence of pre and post-processing packages, in which the methodologies now presented are implemented, inter-faced with a commercial multibody software that is used to study the railway dynamics. The computational tool is applied here to several simulation sce-narios. The purpose is to demonstrate its capabilities on wear prediction by evaluating the influence of trainset design and of track layout on the wheel wear growth. Special attention is also given to study how the wear evolution is affected by the friction conditions between the wheel and rail

Sterile Protection against Plasmodium knowlesi in Rhesus Monkeys from a Malaria Vaccine: Comparison of Heterologous Prime Boost Strategies

Using newer vaccine platforms which have been effective against malaria in rodent models, we tested five immunization regimens against Plasmodium knowlesi in rhesus monkeys. All vaccines included the same four P. knowlesi antigens: the pre-erythrocytic antigens CSP, SSP2, and erythrocytic antigens AMA1, MSP1. We used four vaccine platforms for prime or boost vaccinations: plasmids (DNA), alphavirus replicons (VRP), attenuated adenovirus serotype 5 (Ad), or attenuated poxvirus (Pox). These four platforms combined to produce five different prime/boost vaccine regimens: Pox alone, VRP/Pox, VRP/Ad, Ad/Pox, and DNA/Pox. Five rhesus monkeys were immunized with each regimen, and five Control monkeys received a mock vaccination. The time to complete vaccinations was 420 days. All monkeys were challenged twice with 100 P. knowlesi sporozoites given IV. The first challenge was given 12 days after the last vaccination, and the monkeys receiving the DNA/Pox vaccine were the best protected, with 3/5 monkeys sterilely protected and 1/5 monkeys that self-cured its parasitemia. There was no protection in monkeys that received Pox malaria vaccine alone without previous priming. The second sporozoite challenge was given 4 months after the first. All 4 monkeys that were protected in the first challenge developed malaria in the second challenge. DNA, VRP and Ad5 vaccines all primed monkeys for strong immune responses after the Pox boost. We discuss the high level but short duration of protection in this experiment and the possible benefits of the long interval between prime and boost