Search results for "MOBILITY"
showing 10 items of 922 documents
Obstacles Facing Smaller Business in Developing Countries
2003
Small and medium enterprises (SMEs) play a central role in economic growth and poverty alleviation in developing countries and transition economies. Yet small and medium-scale enterprise may suffer from a number of disadvantages compared with larger firms. Market imperfections, notably those caused by underdeveloped financial and legal systems, typically constrain small firms and severely limit their ability to grow. Economies of scale and entry cost favor large firms, and large entrepreneurs usually wield more political influence. Thus government rules and regulations may also be biased in favor of large firms. To the extent that market and government failures are more prevalent in develop…
Plus d'éducation, pour qui, pour quoi ?
2005
La question des "moyens" semble résumer les revendications syndicales des enseignants. Or l'élévation des niveaux de diplôme ne réduit pas les inégalités sociales et scolaires entre les élèves, ni le taux de chômage des jeunes. C'est qu'il faut autrement, et de façon plus politique, poser la question de l'allocation des ressources et de leur évaluation : qui doit bénéficier de plus d'école ?
In situ, satellite measurement and model evidence on the dominant regional contribution to fine particulate matter levels in the Paris megacity
2015
International audience; Published by Copernicus Publications on behalf of the European Geosciences Union. 9578 M. Beekmann et al.: Evidence for a dominant regional contribution to fine particulate matter levels Abstract. A detailed characterization of air quality in the megacity of Paris (France) during two 1-month intensive campaigns and from additional 1-year observations revealed that about 70 % of the urban background fine particulate matter (PM) is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in situ measurements during short intensive and longer-term campaigns, aerosol optical depth (AOD) measurements from E…
Analysis of Pollutant Emissions on City Arteries—Aspects of Transport Management
2021
The aim of the study is to present a methodology for analyzing pollution emissions in a medium-sized city using modern traffic simulations in the aspect of minimizing exhaust emissions. The scope of the research and the methods of analysis used differ from those applied in big cities projects that can be found in the literature, Therefore the progressive elaboration model has been applied methodically to formulate and carry out the feasibility study. To perform microscopic traffic simulations, the software Simulation of Urban Mobility (SUMO—German Aerospace Center (DLR), Berlin, Germany) was applied. Thanks to the simulations, changes in traffic organization were accurately identified in th…
Cationic polyaspartamide-based nanocomplexes mediate siRNA entry and down-regulation of the pro-inflammatory mediator high mobility group box 1 in ai…
2015
Abstract High-mobility group box 1 (HMGB1) is a nonhistone protein secreted by airway epithelial cells in hyperinflammatory diseases such as asthma. In order to down-regulate HMGB1 expression in airway epithelial cells, siRNA directed against HMGB1 was delivered through nanocomplexes based on a cationic copolymer of poly(N-2-hydroxyethyl)- d,l -aspartamide (PHEA) by using H441 cells. Two copolymers were used in these experiments bearing respectively spermine side chains (PHEA-Spm) and both spermine and PEG2000 chains (PHEA-PEG-Spm). PHEA-Spm and PHEA-PEG-Spm derivatives complexed dsDNA oligonucleotides with a w/w ratio of 1 and higher as shown by a gel retardation assay. PHEA-Spm and PHEA-P…
Novel cationic copolymers of a polyasparthylhydrazide: synthesis and characterization.
2005
Alpha,beta-poly(asparthylhydrazide) (PAHy), a water soluble synthetic polymer, was functionalized by using EDCI chemistry with 3-(carboxypropyl)trimethyl-ammonium chloride (CPTACl) obtaining carboxypropyltrimethyl ammonium copolymers (PAHy-CPTA). Three PAHy-CPTA copolymers at increasing derivatization degrees (38%, 48%, 58%) were chosen for subsequent investigations. The capability of these copolymers to bind, neutralize, and protect DNA against degradation by DNase II was evalued by gel retardation assay and DNA degradation test at pH 5.5. Zeta potential measurements show that all studied polymers are able to neutralize the anionic charge of DNA at polymer/DNA weight ratio in the range of …
Resveratrol, a polyphenolic phytoalexin present in red wine, enhances expression and activity of endothelial nitric oxide synthase.
2002
Background— Estrogens can upregulate endothelial nitric oxide synthase (eNOS) in human endothelial cells by increasing eNOS promoter activity and enhancing the binding activity of the transcription factor Sp1. Resveratrol, a polyphenolic phytoalexin found in grapes and wine, has been reported to act as an agonist at the estrogen receptor. Therefore, we tested the effect of this putative phytoestrogen on eNOS expression in human endothelial cells. Methods and Results— Incubation of human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells with resveratrol for 24 to 72 hours upregulated eNOS mRNA expression in a time- and concentration-dependent manner (up to 2.8-fold)…
International student mobility in Southern-Latin Europe: beyond the EU logics, towards a new space
2018
This paper discusses international student mobility (ISM) in Southern-Latin Europe, specifically Italy, Portugal, and Spain, analysing the inflow of international students as reflected in the UNESCO, OECD and European Commission databases. Only recently Italy, Portugal and Spain, as latecomers, have become more actively involved in ISM dynamics. This trend has been a response to EU pressures to internationalization, instrumented through the consolidation of the Bologna process and the need to build a common space of higher education. The analysis shows that at the intra-European level Italy, Portugal and Spain share similar ISM patterns; however, in the global context other logics shape ISM…
High Wage Workers Match with High Wage Firms: Clear Evidence of the Effects of Limited Mobility Bias
2012
Positive assortative matching implies that high productivity workers and firms match together. However, there is almost no evidence of a positive correlation between the worker and firm contributions in two-way fixed-effects wage equations. This could be the result of a bias caused by standard estimation error. Using German social security records we show that the effect of this bias is substantial in samples with limited inter-firm movement. The correlation between worker and firm contributions to wage equations is unambiguously positive.
Failure analysis of normally-off GaN HEMTs under avalanche conditions
2020
Gallium nitride (GaN) high electron-mobility transistors (HEMTs) are promising devices in the power electronics field owing to their wide bandgap (WBG). However, all the potential advantages provided by their WBG require reliability improvement. In industrial applications, robustness is one of the main factors considered by circuit designers. This study focuses on the observation of the degradation behavior of the main waveforms of unclamped inductive-switching (UIS) test circuits of two different commercial GaN HEMT structures. The relevance of this study lies in the potential applications of these devices to high-voltage applications and automotive systems where they are subjected to many…