Public Transit Capacity and Users Choice: AnExperiment on Downs-Thomson Paradox

We study the Downs-Thomson paradox, a situation where an additional road capacitycan cause an overall increase in transport generalized cost and therefore a decrease in welfarefor transport users. To this end, we build an experiment based on a double market-entrygame (DMEG) where users have to choose between road and public transit after that the op-erator has choosen public transit capacity. The optimal strategy for operator is to minimizecapacity, and the equilibrium for users depend on the endogeneous public transit capacitycompared to exogeneous road capacity. The most important result is that we observe theDowns-Thomson paradox empirically in the laboratory: An increase in road capacity causesshift from road to rail and, at the end, increases total travel costs. But the contrary isnot true: A decrease in road capacity does not cause lower total travel costs, which is incontradiction with our theoretical model. Results also show that the capacity chosen byoperator di¤ers from Nash prediction, levels being signi…cantly higher than those predictedby our model. Moreover, users coordinate remarkably well on Nash equilibrium entry ratewhile capacity has been chosen by operator.traffic equilibrium, public transit, congestion, experimental economics, market entry game

Tomographic imaging and scanning thermal microscopy: thermal impedance tomography

The application of tomographic imaging techniques developed for medical applications to the data provided by the scanning thermal microscope will give access to true three-dimensional information on the thermal properties of materials on a mm length scale. In principle, the technique involves calculating and inverting a sensitivity matrix for a uniform isotropic material, collecting ordered data at several modulation frequencies, and multiplying the inverse of the matrix with the data vector. In practice, inversion of the matrix in impractical, and a novel iterative technique is used. Examples from both simulated and real data are given

Sub-wavelength surface IR imaging of soft-condensed matter

Outlined here is a technique for sub-wavelength infrared surface imaging performed using a phase matched optical parametric oscillator laser and an atomic force microscope as the detection mechanism. The technique uses a novel surface excitation illumination approach to perform simultaneously chemical mapping and AFM topography imaging with an image resolution of 200 nm. This method was demonstrated by imaging polystyrene micro-structures

Downs-Thomson paradox and public transit capacity choice in the laboratory

The aim of this paper is to study empirically the Downs- Thomson (DT) Paradox, a situation where additional road capacity can cause an increase in total travel cost for users that are to choose between Private Car and Public Transit. To this end, we design a laboratory experiment based on a Two-Mode Entry Game where subjects have to enter either in a road mode or in a public transit mode. Road capacity being exogenous, public transit capacity is chosen by the operator. In this theoretical framework, the optimal strategy for operator is to minimize capacity, and the equilibrium for users depends on the endogenous public transit capacity compared to exogenous road capacity. As a consequence, an exogenous increase of road capacity, by shifting users’ equilibrium, will cause a decrease in payoffs for all users (DT Paradox). On the contrary, a decrease in Road Capacity should increase total payoff. To test these theoretical predictions, two experimental treatments are implemented, each of them consisting in a certain capacity level for Road. The most important result is that Downs-Thomson Paradox is observed within the laboratory: An increase in road capacity actually shifts participants from Public Transit to Road, causing a decrease in payoffs for the entire group. But the reverse is not empirically true: A decrease in capacity does not raise payoffs, which contradicts our theoretical model. Results also show that the capacity chosen by operator differs from Nash prediction, levels being higher than those predicted by our model

Sub-wavelength infrared imaging of lipids

Infrared absorption spectroscopy of lipid layers was performed by combining optics and scanning probe microscopy. This experimental approach enables sub-diffraction IR imaging with a spatial resolution on the nanometer scale of 1, 2-dioleoyl-sn-glycero-3-phosphocholine lipid layers

Etude Nationale sur la détection des jeunes talents sportifs en Algérie

L’objectif principal de cette étude est d’évaluer de la croissance morpho-fonctionnelle des enfants scolarisés et de déterminer les profils morphologiques, selon les différentes willayas du territoire national âgés de 06 à12 ans. L’établissement des références nationales seront un support pour la détection des jeunes talents sportifs et leur formation en fonction des différentes régions du territoire nationa

Vibrational biospectroscopy characterises biochemical differences between cell types used for toxicological investigations and identifies alterations induced by environmental contaminants

The use of cell-based assays is essential in reducing the number of vertebrates used in the investigation of chemical toxicities and in regulatory toxicology assessment. An important factor in obtaining meaningful results which can be accurately extrapolated is the use of biologically appropriate cell lines. In this preliminary study, ATR-FTIR spectroscopy with multivariate analysis was used to assess the fundamental biomolecular differences between a commonly used cell line, MCF-7 cells, and an environmentally relevant cell line derived from Mallard (Anas platyrhynchos) dermal fibroblasts. To better understand differences in basic cell biochemistry, the cells were analysed in the untreated state or post-exposure to PCB and PBDE congeners. The main spectral peaks in spectra from both cell types were associated with cellular macromolecules, particularly proteins and lipids but the spectra also revealed some cell-specific differences. Spectra from untreated Mallard fibroblasts spectra contained a large peak associated with lipids. The cell-related differences in lipid and DNA were also identified as regions of spectral alteration induced by PBDE and PCB exposure. Although lipid alterations were observed in post-treatment spectra from both cell types, these may be of more significance to Mallard fibroblasts, which may be due to increased intracellular lipid as determined by Nile red staining. Untreated MCF-7 cell spectra contained unique peaks related to DNA and nucleic acids. DNA associated spectral regions were also identified as areas of considerable alteration in MCF-7 cells exposed to some congeners including PBDE 47 and PCB 153. The findings indicate that in their native state, MCF-7 and Mallard cells have unique biochemical differences, which can be identified using ATR-FTIR spectroscopy. Such differences in biochemical composition differences, which may influence cell susceptibility to environmental contaminants and therefore influence the choice of cell type used in toxicology experiments. This is the first study to analyse the biochemistry of a Mallard dermal fibroblast cell line and to use ATR-FTIR spectroscopy for this purpose. ATR-FTIR spectroscopy is demonstrated as a useful tool for exploration of biomolecular variation at the cellular level and with further development, it could be used as part of a panel of cell-based assays to indicate when different results might be seen in environmental species compared to currently used cell lines. This article is protected by copyright. All rights reserve