Generalized Multivariate Extreme Value Models for Explicit Route Choice Sets

This paper analyses a class of route choice models with closed-form probability expressions, namely, Generalized Multivariate Extreme Value (GMEV) models. A large group of these models emerge from different utility formulas that combine systematic utility and random error terms. Twelve models are captured in a single discrete choice framework. The additive utility formula leads to the known logit family, being multinomial, path-size, paired combinatorial and link-nested. For the multiplicative formulation only the multinomial and path-size weibit models have been identified; this study also identifies the paired combinatorial and link-nested variations, and generalizes the path-size variant. Furthermore, a new traveller's decision rule based on the multiplicative utility formula with a reference route is presented. Here the traveller chooses exclusively based on the differences between routes. This leads to four new GMEV models. We assess the models qualitatively based on a generic structure of route utility with random foreseen travel times, for which we empirically identify that the variance of utility should be different from thus far assumed for multinomial probit and logit-kernel models. The expected travellers' behaviour and model-behaviour under simple network changes are analysed. Furthermore, all models are estimated and validated on an illustrative network example with long distance and short distance origin-destination pairs. The new multiplicative models based on differences outperform the additive models in both tests

Anarchy, Groups, and Conflict: An Experiment on the Emergence of Protective Associations

In this paper, we investigate the implications of the philosophical considerations presented in Nozick’s Anarchy, State, and Utopia, by examining group formation in a laboratory setting where subjects engage in both cooperative and conflictual interactions. We endow participants with a commodity used to generate earnings, plunder others, or protect against plunder. In our primary treatment, we allow participants to form groups to pool their resources. We conduct a baseline comparison treatment that does not allow group formation. We find that allowing subjects to organize themselves into groups does not lead to more cooperation and may in fact exacerbate tendencies for conflict.Nozickian protective associations, Conflict, Anarchy, Experimental economics

A new robust diagnostic polymerase chain reaction for determining the mating status of female Anopheles gambiae mosquitoes.

The principal malaria vector in Africa, Anopheles gambiae, contains two pairs of autosomes and one pair of sex chromosomes. The Y chromosome is only associated with males and other Y chromosome-specific DNA sequences, which are transferred to women during mating. A reliable tool to determine the mating status of dried wild An. gambiae females is currently lacking. DNA was extracted from dried virgin and mated females and used to test whether Y chromosome-specific polymerase chain reaction (PCR) markers can be successfully amplified and used as a predictor of mating. Here we report a new PCR-based method to determine the mating status among successfully inseminated and virgin wild An. gambiae females, using three male-specific primers. This dissection-free method has the potential to facilitate studies of both population demographics and gene flow from dried mosquito samples routinely collected in epidemiologic monitoring and aid existing and new malaria-vector control approaches

Managing intoxications with nicotine-containing e-liquids

INTRODUCTION: Nicotine is an addictive and poisonous agent. The recent development of e-cigarettes has caused a new demand for highly concentrated nicotine-containing solutions. These concentrated nicotine solutions have also increased the risk of nicotine overdoses. AREAS COVERED: Essential factors for nicotine exposure are the concentration of the nicotine-containing e-liquid solution and its pharmacokinetics. Liquid nicotine refills contain nicotine in varying concentrations, which vary widely between and within products. The pharmacokinetics of nicotine are dependent on the route of administration, renal/hepatic clearance and urinary pH. The dose is another essential determinant of nicotine exposure. There is a considerable discrepancy between the generally accepted lethal dose and symptoms reported in case studies. Ingested doses correlate poorly to clinical symptoms. Symptoms of liquid nicotine toxicity vary from mild to severe between patients and are the result of overstimulation of nicotinic acetylcholine receptors, which may lead to fatal respiratory failure and cardiovascular collapse. EXPERT OPINION: The literature on nicotine-containing e-liquid intoxications originating from vaping device refills are mainly case reports. Based on these case reports, we propose a treatment plan which is primarily symptomatic. Research should focus on providing insight on its toxicity, based on oral and transdermal pharmacokinetics and on toxicodynamics