BackgroundThe specific role of microglia on Aβ-mediated neurotoxicity is difficult to assign in vivo due to their complicated environment in the brain. Therefore, most of the current microglia-related studies employed the isolated microglia. However, the previous in vitro studies have suggested either beneficial or destructive function in microglia. Therefore, to investigate the phenotypes of the isolated microglia which exert activity of neuroprotective or destructive is required.ResultsThe present study investigates the phenotypes of isolated microglia on protecting neuron against Aβ-mediated neurotoxicity. Primary microglia were isolated from the mixed glia culture, and were further cultured to distinct phenotypes, designated as proliferating amoeboid microglia (PAM) and differentiated process-bearing microglia (DPM). Their inflammatory phenotypes, response to amyloid β (Aβ), and the beneficial or destructive effects on neurons were investigated. DPM may induce both direct neurotoxicity without exogenous stimulation and indirect neurotoxicity after Aβ activation. On the other hand, PAM attenuates Aβ-mediated neurotoxicity through Aβ phagocytosis and/or Aβ degradation.ConclusionsOur results suggest that the proliferating microglia, but not the differentiated microglia, protect neurons against Aβ-mediated neurotoxicity. This discovery may be helpful on the therapeutic investigation of Alzheimer’s disease.

Railway controllers play a pivotal role in service recovery of normal rail system operations when incidents and accidents occur. Those in this position must have sufficient competence to overcome task difficulties caused by accident uncertainties. This study adopts Taiwan's railway system as a case study to diagnose railway-controller-perceived competence when facing diverse tasks during incidents and accidents that are derived from a proposed conceptual model. Railway-controller-perceived competence is measured using the Rasch model. Analytical results indicate that working with an external rescue agency handling a rescue operation, explanations to the public, and communication with an external rescue agency are considered the most troublesome tasks. Additionally, railway-controller-perceived competence differs based on the work experience. This information will prove useful for rail system operators and government regulators when designing and regulating railway controller competence management systems. STATEMENT OF RELEVANCE: This study presents a systematic approach for examining the gap between railway-controller-perceived competence and task difficulties associated with incidents and accidents. The relevance of findings encompasses the effects of transportation ergonomics and railway issues on the problem-solving competence and decision-making skills of railway controllers, and the competence management system.

Waiting time influences the overall perception of service quality. The passengerperceived waiting time can determine their waiting experience. The concept of waiting time refers to the comparison between the passengers' inherent tolerance of waiting and the possible improvement scenarios. This study investigates the passengers' tolerance of waiting under various scenarios of train delays in order to improve their perceived waiting time. We propose the adoption of a modern psychometric method utilizing the Rasch model to measure a subjective latent construct known as 'wait tolerance'. The Rasch measurement provides mathematical procedures for transforming scores from an ordinal to an interval scale to observe which scenarios can reduce certain passengers' perceived waiting time in the case of a delay. Empirical results show that 'uncontrollable circumstances', 'friendly staff attitudes', and 'providing appropriate messages of apology' can improve the passenger-perceived waiting time during train delays. Likewise, distinct differences are found in the passengers' tolerance of waiting in terms of various personal characteristics, such as gender, age, and train riding frequency. The findings propose the implementation of strategies for improvement by rail system operators, as well as for regulators to define a reasonable service level in the case of train delays. The reviews show possible future innovative research orientations as well.