Background: Several studies have analysed the pollution issues owing to road traffic in Cotonou, Benin. Concentration levels of particles are higher on high traffic than a low traffic. The exposure of human population...Background: Several studies have analysed the pollution issues owing to road traffic in Cotonou, Benin. Concentration levels of particles are higher on high traffic than a low traffic. The exposure of human populations to air pollution is more intense on the roads. In Benin, the density of traffic on the crossroads is indeed more important. Are traffic locations such as crossroads, areas where the level of exposure PM2.5 is increased? Methods: This study was conducted along the 5 km high-traffic road in the city of Cotonou. It is a high traffic lane with two crossroads. Sampling and measurements were carried out in dry sea-son (January and February) and rainy season (June and July). For each season the measurements were made over two months from 7 am to 9 pm. PM2.5 measurements were made at different locations at crossroads and also along the track. To compare concentrations of PM2.5 at crossroads and outside of roundabout, we used the Generalized Linear Mixed Model. Results: In the rainy season the PM2.5 hourly concentrations ranged between 400 μg/m3 and 500 μg/m3 while in the dry season 100 μg/m3 and 300 μg/m3. In the rainy season, the average of PM2.5 concentration was 463.25 ± 66.21 μg/m3 at crossroads and 264.75 ± 50.97 μg/m3 outside of crossroads. In the dry season, the average of PM2.5 concentration was 232.75 ± 97.29 μg/m3 at crossroads and 123.31 ± 63.79 μg/m3 outside of crossroads. Both in dry and rainy seasons, PM2.5 concentration level peaks are observed from 7 am to 9 am and from 7 pm to 9 pm. The Generalized Linear Mixed Model showed that there is high significant difference between concentrations of PM2.5 at crossroads compared to outside of crossroads. Occupation of the roadside (in particular crossroads) for various economic activities is common practice in Cotonou thus health risk for people working around crossroads increases. Conclusion: Locations such as crossroads are areas where the level of exposure PM2.5 is highest on road traffics.展开更多
In 1997, international arms control and disarmament comes once again to anew crossroads. A consensus has as yet to be built concerning the next step. Forthe US-led Western nations, the focus continues to be prevention...In 1997, international arms control and disarmament comes once again to anew crossroads. A consensus has as yet to be built concerning the next step. Forthe US-led Western nations, the focus continues to be prevention against the pro-liferation of Weapons of Mass Destruction (WMD), missiles and high-tech conven-tional weapons and accelerated development and deployment of anti-missile sys-展开更多
Plants deploy numerous plasma membrane receptors to sense and rapidly react to environmental changes. Correct localization and adequate protein levels of the cell-surface receptors are critical for signaling activatio...Plants deploy numerous plasma membrane receptors to sense and rapidly react to environmental changes. Correct localization and adequate protein levels of the cell-surface receptors are critical for signaling activation and modulation of plant development and defense against pathogens. After ligand binding, receptors are internalized for degradation and signaling attenuation. However, one emerging notion is that the Iigand-induced endocytosis of reCeptor complexes is important for the signal duration, amplitude, and specificity. Recently, mutants of maior endocytosis players, including clathrin and dynamin, have been shown to display defects in activation of a subset of signal transduction pathways, implying that signaling in plants might not be solely restricted to the plasma membrane. Here, we summarize the up-to-date knowledge of receptor complex endocytosis and its effect on the signaling outcome, in the context of plant development and immunity.展开更多
This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the ge...This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the genetic algorithm(GA),a system that allows to accurately decide in real time on the light switching pattern that minimizes the traffic waiting time.Equally importantly,the inherent crossroads constraints,namely,the security of their users and the structure thereof,also referred to as the antagonism principle,are considered in the proceeding of this method.The implementation of this model on two crossroads significantly decreases the waiting time and regulates the traffic flow.Therefore,the adaptive control system based on the GA proves efficient compared to the nonadaptive system.展开更多
The Red Cross Society of China faces a serious credibility crisis and tries to regain public trust Guo Meimei has become a household name in China since late June.On June 21,she caught the attention of netizens for th...The Red Cross Society of China faces a serious credibility crisis and tries to regain public trust Guo Meimei has become a household name in China since late June.On June 21,she caught the attention of netizens for the first time展开更多
The levels of roadside PM10 in Beijing, China, were investigated in 2011 and 2012 on a seasonal basis to estimate the population exposure to particulates for three road types. The measurements of PM10 were also conduc...The levels of roadside PM10 in Beijing, China, were investigated in 2011 and 2012 on a seasonal basis to estimate the population exposure to particulates for three road types. The measurements of PM10 were also conducted in the southern Chinese megacity of Guangzhou for comparison purposes. The results showed that roadside PMlo in Beijing correlated strongly with the PM10 background in the urban atmosphere. The levels of PM10 in street canyons were markedly higher than those along the open roads and in crossroad areas because of limited ventilation. An elevation of PM10 was observed in April, which was possibly due to the sand storms that frequently occur in the spring. Based on these observations, roadside PM10 in Beijing could have multiple origins and was to some extent dispersion- governed. In Guangzhou, the roadside PM10 did not closely relate to the background values. The PM10 pollution was greatly affected by local traffic conditions. The simulation of PM10 for different road types was completed during the study period using the Motor Vehicle Emissions Factor Model （MOBILE6.2） as an emission model and the California Line Source Dispersion Model （CALINE4） and Operational Street Pollution Model （OSPM） as dispersion models. The MOBILE6.2/CALINE4 software package was demonstrated to be sufficient for the simulation of PM10 in the open roads and crossroad areas in both Beijing and Guangzhou, and the simulation results of roadside PM10 in the street canyons by the MOBILE6.2/OSPM package were in close agreement with those of the measurements.展开更多
文摘Background: Several studies have analysed the pollution issues owing to road traffic in Cotonou, Benin. Concentration levels of particles are higher on high traffic than a low traffic. The exposure of human populations to air pollution is more intense on the roads. In Benin, the density of traffic on the crossroads is indeed more important. Are traffic locations such as crossroads, areas where the level of exposure PM2.5 is increased? Methods: This study was conducted along the 5 km high-traffic road in the city of Cotonou. It is a high traffic lane with two crossroads. Sampling and measurements were carried out in dry sea-son (January and February) and rainy season (June and July). For each season the measurements were made over two months from 7 am to 9 pm. PM2.5 measurements were made at different locations at crossroads and also along the track. To compare concentrations of PM2.5 at crossroads and outside of roundabout, we used the Generalized Linear Mixed Model. Results: In the rainy season the PM2.5 hourly concentrations ranged between 400 μg/m3 and 500 μg/m3 while in the dry season 100 μg/m3 and 300 μg/m3. In the rainy season, the average of PM2.5 concentration was 463.25 ± 66.21 μg/m3 at crossroads and 264.75 ± 50.97 μg/m3 outside of crossroads. In the dry season, the average of PM2.5 concentration was 232.75 ± 97.29 μg/m3 at crossroads and 123.31 ± 63.79 μg/m3 outside of crossroads. Both in dry and rainy seasons, PM2.5 concentration level peaks are observed from 7 am to 9 am and from 7 pm to 9 pm. The Generalized Linear Mixed Model showed that there is high significant difference between concentrations of PM2.5 at crossroads compared to outside of crossroads. Occupation of the roadside (in particular crossroads) for various economic activities is common practice in Cotonou thus health risk for people working around crossroads increases. Conclusion: Locations such as crossroads are areas where the level of exposure PM2.5 is highest on road traffics.
文摘In 1997, international arms control and disarmament comes once again to anew crossroads. A consensus has as yet to be built concerning the next step. Forthe US-led Western nations, the focus continues to be prevention against the pro-liferation of Weapons of Mass Destruction (WMD), missiles and high-tech conven-tional weapons and accelerated development and deployment of anti-missile sys-
基金supported by the Research Foundation-Flanders(G008416N)
文摘Plants deploy numerous plasma membrane receptors to sense and rapidly react to environmental changes. Correct localization and adequate protein levels of the cell-surface receptors are critical for signaling activation and modulation of plant development and defense against pathogens. After ligand binding, receptors are internalized for degradation and signaling attenuation. However, one emerging notion is that the Iigand-induced endocytosis of reCeptor complexes is important for the signal duration, amplitude, and specificity. Recently, mutants of maior endocytosis players, including clathrin and dynamin, have been shown to display defects in activation of a subset of signal transduction pathways, implying that signaling in plants might not be solely restricted to the plasma membrane. Here, we summarize the up-to-date knowledge of receptor complex endocytosis and its effect on the signaling outcome, in the context of plant development and immunity.
文摘This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the genetic algorithm(GA),a system that allows to accurately decide in real time on the light switching pattern that minimizes the traffic waiting time.Equally importantly,the inherent crossroads constraints,namely,the security of their users and the structure thereof,also referred to as the antagonism principle,are considered in the proceeding of this method.The implementation of this model on two crossroads significantly decreases the waiting time and regulates the traffic flow.Therefore,the adaptive control system based on the GA proves efficient compared to the nonadaptive system.
文摘The Red Cross Society of China faces a serious credibility crisis and tries to regain public trust Guo Meimei has become a household name in China since late June.On June 21,she caught the attention of netizens for the first time
基金supported by the Forestry Public Welfare Project of China(No.20130430104)the National Natural Science Foundation of China(No.51008025)+1 种基金the Fundamental Research Funds for the Central Universities(No.TD2011-22)the National Undergraduate Training Programs for Innovation and Entrepreneurship(No.201210022078)
文摘The levels of roadside PM10 in Beijing, China, were investigated in 2011 and 2012 on a seasonal basis to estimate the population exposure to particulates for three road types. The measurements of PM10 were also conducted in the southern Chinese megacity of Guangzhou for comparison purposes. The results showed that roadside PMlo in Beijing correlated strongly with the PM10 background in the urban atmosphere. The levels of PM10 in street canyons were markedly higher than those along the open roads and in crossroad areas because of limited ventilation. An elevation of PM10 was observed in April, which was possibly due to the sand storms that frequently occur in the spring. Based on these observations, roadside PM10 in Beijing could have multiple origins and was to some extent dispersion- governed. In Guangzhou, the roadside PM10 did not closely relate to the background values. The PM10 pollution was greatly affected by local traffic conditions. The simulation of PM10 for different road types was completed during the study period using the Motor Vehicle Emissions Factor Model （MOBILE6.2） as an emission model and the California Line Source Dispersion Model （CALINE4） and Operational Street Pollution Model （OSPM） as dispersion models. The MOBILE6.2/CALINE4 software package was demonstrated to be sufficient for the simulation of PM10 in the open roads and crossroad areas in both Beijing and Guangzhou, and the simulation results of roadside PM10 in the street canyons by the MOBILE6.2/OSPM package were in close agreement with those of the measurements.
