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TRAFFIC congestions and accidents are major concerns in today’s transportation systems. This thesis investigates how to improve traffic throughput by reducing or eliminating bottlenecks on highways, in particular for merging situations such as intersections where a ramp leads onto the highway. In our work, cars are equipped with sensors that can measure distance to neighboring cars, and communicate their velocity and acceleration readings with one another. Sensor-enabled cars can locally exchange sensed information about the traffic and adapt their behavior much earlier than regular cars. / We propose proactive algorithms for merging different streams of sensor-enabled cars into a single stream. A proactive merging algorithm decouples the decision point from the actual merging point. Sensor-enabled cars allow us to decide where and when a car merges before it arrives at the actual merging point. This leads to a significant improvement in traffic flow as velocities can be adjusted appropriately. We compare proactive merging algorithms against the conventional priority-based merging algorithm in a controlled simulation environment. Experimental results show that proactive merging algorithms outperform the priority-based merging algorithm in terms of flow and delay. / More importantly, the imprecise information (errors in sensor measurements) is a major challenge for merging algorithms, because inaccuracies can potentially lead to unsafe merging behaviors. In this thesis, we investigate how the accuracy of sensors impacts merging algorithms, and design robust merging algorithms that tolerate sensor errors. Experimental results show that one of our proposed merging algorithms, which is based on the theory of time geography, is able to guarantee safe merging while tolerating two to four times more imprecise positioning information, and can double the road capacity and increase the traffic flow by 25%.

TRAFFIC congestions and accidents are major concerns in today’s transportation systems. This thesis investigates how to improve traffic throughput by reducing or eliminating bottlenecks on highways, in particular for merging situations such as intersections where a ramp leads onto the highway. In our work, cars are equipped with sensors that can measure distance to neighboring cars, and communicate their velocity and acceleration readings with one another. Sensor-enabled cars can locally exchange sensed information about the traffic and adapt their behavior much earlier than regular cars. / We propose proactive algorithms for merging different streams of sensor-enabled cars into a single stream. A proactive merging algorithm decouples the decision point from the actual merging point. Sensor-enabled cars allow us to decide where and when a car merges before it arrives at the actual merging point. This leads to a significant improvement in traffic flow as velocities can be adjusted appropriately. We compare proactive merging algorithms against the conventional priority-based merging algorithm in a controlled simulation environment. Experimental results show that proactive merging algorithms outperform the priority-based merging algorithm in terms of flow and delay. / More importantly, the imprecise information (errors in sensor measurements) is a major challenge for merging algorithms, because inaccuracies can potentially lead to unsafe merging behaviors. In this thesis, we investigate how the accuracy of sensors impacts merging algorithms, and design robust merging algorithms that tolerate sensor errors. Experimental results show that one of our proposed merging algorithms, which is based on the theory of time geography, is able to guarantee safe merging while tolerating two to four times more imprecise positioning information, and can double the road capacity and increase the traffic flow by 25%.

In this study, we investigated the mechanism of nitrogen excretion in the soil nematode Caenorhabditis elegans. Utilizing the scanning ion electrode technique (SIET), it was shown for the first time in nematodes that the excretory cell promotes a secretion of ions, including Na+, K+, H+ and Ca2+. In addition, observations from experiments exposing the animal to various environmental pH regimes suggested that the mode of ammonia excretion is dependent on acidification of the unstirred boundary layer, supported also by a detected H+-net-excretion over the hypodermis employing SIET. Pharmacological experiments, SIET and enzyme activity measurements implicated the participation of a functional microtubule network, V-type H+-ATPase, carbonic anhydrase, Na+/K+-ATPase, and apical Na+-channels in the ammonia excretion mechanism of this roundworm. Most importantly, employing ammonia transporter deficient Saccharomyces cerevisiae we were able to show for the first time that an invertebrate Rh-like protein (Rhr-1) does indeed function as an ammonia transporter. Further, a second Rh-protein, Rhr-2, was found to be predominantly expressed in the hypodermis. Knock-out experiments on this transporter further suggested participation of Rhr-2 in the apical ammonia trapping mechanism. Overall, the results of this study provided evidence for a novel ammonia excretion mechanism over the hypodermis, which exhibits features commonly seen in both freshwater (ammonia trapping) and seawater inhabiting species (vesicular transport and exocytosis). / October 2015

The aim of this paper is to guarantee improved quality of life for inhabitants by modelling the network of public transport routes in Vilnius. To achieve the aim of the paper, the following tasks were formulated: • analysis of measures of modelling the public transport passenger flows, as well as analysis their function, • establish the main criteria of the public transport’s modelling in Vilnius, • modelling of the public transport route networks in accordance with the established criteria, • assessment of the influence of speedy trams on the distribution of passenger flows within the public transport of Vilnius, • proposals on the possibilities of application of the public transport modelling criteria for other Lithuanian towns.

Les progrès considérables effectués durant les trente dernières années permettent de guérir actuellement plus de 75% des enfants atteints d’un cancer. Néanmoins, certains types de tumeur, comme les gliomes de haut grade et les neuroblastomes métastatiques des enfants de plus de un an, gardent un pronostic particulièrement sombre. De nouvelles stratégies thérapeutiques doivent donc être développées dans ces indications. Dans cette optique, nous avons étudié les effets de deux nouvelles molécules ciblées, le cilengitide, inhibiteur des intégrines αvβ3 et αvβ5, et le F14512, inhibiteur de la topoisomérase II dont la délivrance est vectorisée via le système de transport des polyamines, sur des modèles précliniques de gliomes pédiatriques et de neuroblastomes.Nous avons montré pour la première fois l’existence d’une expression variable d’αvβ3 et αvβ5 dans nos modèles de lignées cellulaires pédiatriques, peu modifiée par les radiations ionisantes. Le traitement par cilengitide a entraîné une inhibition dose-dépendante de la croissance des cellules exprimant αvβ3, liée à un rapide détachement cellulaire et à une sensibilité à l’anoïkis. Cette inhibition de croissance et le détachement cellulaire n’étaient pas corrélés au niveau d’expression des intégrines αvβ3 et αvβ5. Néanmoins, nos travaux semblent montrer que la cible principale du cilengitide est l’intégrine αvβ3. Le traitement par radiations ionisantes n’a pas modifié le détachement induit par le cilengitide dans nos modèles.Nous avons également mis en évidence une activité du système de transport des polyamines dans nos modèles, permettant ainsi une incorporation active du F14512 dans nos cellules de neuroblastomes. Nous avons montré une supériorité de la cytotoxicité du F14512 par rapport à l’étoposide in vitro, et son effet antitumoral a été démontré sur un modèle in vivo. Ces résultats, ainsi que l’effet globalement synergique de l’association du F14512 avec les sels de platine, sont de solides arguments pour poursuivre le développement de cette molécule, en phase clinique chez les patients atteints d’un neuroblastome. Par ailleurs, d’autres investigations pourraient être envisagées dans d’autres types tumoraux dans lesquels l’étoposide occupe une place importante. L’effet radiosensibilisant du F14512 pourrait dans ce cadre ouvrir des perspectives dans la prise en charge des médulloblastomes.[...] / Despite the progress made during the past thirty years leading to cure about 75% of children with cancer, the prognosis of high-grade gliomas (HGG) in children and metastatic neuroblastoma remains poor. The aim of the thesis was to study in vitro the mechanisms of action of a novel inhibitor of αvβ3 and αvβ5 integrins, so-called cilengitide , and of a new topoisomerase II inhibitor targeting the polyamine transport system (PTS), so-called F14512, used as a single drug or in combination therapy in neuroblastoma and pediatric gliomas cell lines. Our panel of cell lines included three pediatric HGG, 2 low-grade pediatric glioma and four neuroblastoma cell lines as well as one adult HGG cell line. The first part of the work involved cilengitide, and was based on clinical and preclinical data previously obtained in adult glioblastoma. There was no data concerning the effect of cilengitide on pediatric HGG or neuroblastoma cells nor about its use in combination with radiation therapy in children. Similarly, no data were available about the level of expression of αvβ3 and αvβ5 integrins on the surface of glioma and pediatric neuroblastoma cells. We showed by flow cytometry significant and various αvβ3 and αvβ5 integrin expression levels in our four neuroblastomas and in most of glioma cell lines. Those expression levels were unrelated to tumor grade. UW479 cells expressed only αvβ5 integrin and therefore served as a negative control. Irradiation of glioma cells slightly increased αvβ3 expression in SF188, KNS42 and Res259 cell lines without inducing de novo integrin expression in UW479 cells. Cilengitide treatment resulted in a dose-dependent inhibition of cell growth leading to obtain an IC50 in the three cell lines tested. UW479 cells were not sensitive to Cilengitide, suggesting that Cilengitide’s action largely depends on αvβ3 inhibition. It was not possible to determine an IC50 value in the adult prototypical U87MG cell line.Cilengitide treatment resulted in a rapid and dose -dependent detachment of more than 50% of our cells expressing αvβ3 when cultured in adherent conditions on vitronectin, which is a specific matrix of integrins, whereas it remained without effect when the cells were grown on collagen, a nonspecific matrix. The growth inhibition induced by cilengitide was comparable to that observed when cells were seeded on polyHEMA gel in physically non-adherent conditions. Not surprisingly, the cilengitide induced no detachment of UW479 cells regardless of the matrix used. In contrast, cell viability assays showed a strong growth inhibition when these cells were seeded on polyHEMA gel. Interestingly, U87MG cells remained able to grow despite a strong detachment induced by cilengitide, suggesting a resistance to anoikis. Finally, inhibition of cell growth induced by cilengitide seemed only linked to cell detachment and corresponded to cell death by anoikis. These inhibitions of cell detachment and cell growth were not correlated with the levels of expression of integrins [...].

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / With the rapid development of urban economy, there are bus increasing, route extending, and shuttle frequency increasing etc. At the same time, road construction is subject to land surface, so traffic jam often occurs. It is a big trouble for life of citizens and problem for economy development. So it needs to be improved as fast as possible. Vehicle monitoring system for public traffic in Beijing can expediently monitor the state of each controlled bus, thereby making perfect management. With the integration of GPS, analog trunked communication and digital map, the old, blinding manage system of public traffic would be changed into advanced, visualized management mode, and several routes are dispatched in one dispatch center at the same time. The system frame and its components are introduced in this paper.

Thesis (Ph.D.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 210 pages. Includes Vita. Includes bibliographical references.