Cell Toxicity and Uptake of RRR-Alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS) by Various Cell ines \u3cem\u3eIn Vitro\u3c/em\u3e.

This research focused on investigating and comparing the cytotoxicity and cellular uptake of RRR-alpha-tocopheryl polyethylene glycol succinate (TPGS, with that of alpha-tocopheryl succinate (α-TS). Both TPGS and α-TS are water-soluble forms of vitamin E with important clinical applications. Cytotoxicity assays with RAW 264.7 and LNCaP cells incubated overnight with TPGS or α-TS at concentrations ≥ 12.4 μM suggest that α-TS is more cytotoxic than TPGS. Macrophages were found to be more sensitive than LNCaP cells when treated with similar concentrations of α-TS. For both cell lines, most of the TPGS or α-TS taken up remained esterified after 24 hours. Our results suggest that cell death was due to TPGS and/or α-TS and not alpha-tocopherol. A para-hydroxyanilide of α-TS (p-HATS) that could be used to distinguish between cellular TPGS and α-TS was studied. It was found that p-HATS can be detected electrochemically and that it is hydrolyzed to α-TOH

Node Ranking in Wireless Sensor Networks with Linear Topology

International audienceIn wireless sensor networks with linear topology, knowing the physical order in which nodes are deployed is useful not only for the target application, but also to some network services, like routing or data aggregation. Considering the limited resources of sensor nodes, the design of autonomous protocols to find this order is a challenging topic. In this paper, we propose a distributed and iterative centroid-based algorithm to address this problem. At each iteration, the algorithm selects two virtual anchors and finds the order of a subset of nodes, placed between these two anchors. The proposed algorithm requires local node connectivity knowledge and the identifier of the first sensor node of the network, which is the only manually configured parameter. This solution, scalable and lightweight from the deployment and maintenance point of view, is shown to be robust to connectivity degradation, correctly ordering more than 95% of the nodes, even under very low connectivity condition

WARIM: Wireless Sensor Network Architecture for a Reliable Intersection Monitoring

International audienceA traffic light controller takes as input an estimation of the number of vehicles entering the intersection and produces as output a light plan, with the objective to reduce the traffic jam. The quality of the input traffic estimation is a key consideration on the performance of the traffic light controller. The advent of Wireless Sensor Networks, with their relatively low deployment and operation price, led to the development of several sensor-based architectures for intersection monitoring. We show in this paper that the solutions proposed in the literature are unrealistic in terms of communication possibilities and that they do not allow a measure of the vehicular queue length at a lane level. Based on extensive experimental results, we propose an energy efficient, low cost and lightweight multi-hop wireless sensor network architecture to measure with a good accuracy the vehicle queue length, in order to have a more precise vision of traffic at the intersection. Associated challenges are then discussed, such as self-configuration, routing and energy harvesting, which should be addressed in order to reduce the cost of the proposed solution and to improve the performance of the target application

Node Ranking in Wireless Sensor Networks with Linear Topology

International audienceIn wireless sensor networks with linear topology, knowing the physical order in which nodes are deployed is useful not only for the target application, but also to some network services, like routing or data aggregation. Considering the limited resources of sensor nodes, the design of autonomous protocols to find this order is a challenging topic. In this paper, we propose a distributed and iterative centroid-based algorithm to address this problem. At each iteration, the algorithm selects two virtual anchors and finds the order of a subset of nodes, placed between these two anchors. The proposed algorithm requires local node connectivity knowledge and the identifier of the first sensor node of the network, which is the only manually configured parameter. This solution, scalable and lightweight from the deployment and maintenance point of view, is shown to be robust to connectivity degradation, correctly ordering more than 95% of the nodes, even under very low connectivity condition

Antioxidant benzophenones and xanthones from the root bark of Garcinia smeathmannii

A new geranylated xanthone (1) was isolated from the root bark extract of Garcinia smeathmannii Oliver along with known guttiferone I, isoxanthochymol, smeathxanthones A and B, and triacontanyl caffeate. The structures of these compounds were elucidated by spectral analysis and by comparison with the reported data. These compounds showed significant antioxidant DPPH radical scavenging activities.   KEY WORDS: Garcinia smeathmanii, Xanthone, Antioxidant  Bull. Chem. Soc. Ethiop. 2006, 20(2), 247-252

Polyanxanthone A, B and C, three xanthones from the wood trunk of Garcinia polyantha Oliv.

Three xanthones, polyanxanthone A (1), B (2) and C (3) have been isolated from the methanol extract of the wood trunk of Garcinia polyantha, along with five known xanthones: 1,3,5-trihydroxyxanthone (4); 1,5-dihydroxyxanthone (5); 1,3,6,7-tetrahydroxyxanthone (6); 1,6-dihydroxy-5-methoxyxanthone (7) and 1,3,5,6-tetrahydroxyxanthone (8). Their structures were determined by means of 1D- and 2D-NMR techniques. Some of the above compounds were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.info:eu-repo/semantics/publishedVersio

Earlinet - lidar algorithm intercomparison

Postprint (published version

Architecture autonome d'un réseau de capteurs pour le monitoring du trafic véhiculaire à un carrefour

In many countries, because of the limited financial budget, the growth of road infrastructures is low compared to the growth of population and the number of vehicles in urban areas. Such a context does not make the task easy for authorities in charge of the management of transportation systems. The introduction of information and communication technologies (ICT) allows to better address these issues. Vehicular traffic management at intersections has an impact on the traffic jam observed in the whole city. In this thesis, our goal is to propose a low-cost, lightweight and autonomous Wireless Sensors Network (WSN) architecture for vehicular traffic monitoring, especially at an intersections. Vehicular traffic data collected can be used, for instance, for intelligent traffic lights management. In the WSN architecture proposed in the literature for vehicular traffic monitoring, underground sensors are used. In terms of network communication, these architectures are not realistic. Nowadays, surface-mounted sensors are proposed by manufacturers. The first contribution of this thesis is an experimental characterization of wireless links in a WSN with sensors deployed at the ground level. We evaluate the impact of several parameters like the proximity of the ground surface, the communication frequency and the messages size on the link quality. Result show a poor link quality at ground level. Based on the conclusions of the experiments, the second contribution of this thesis is WARIM, a new WSN architecture for vehicular traffic monitoring at an intersection. In WARIM, the sensors deployed on a lane form a multi-hop WSN with a linear topology (LWSN). In this network, all the data are forwarded toward the sink. In a network with such properties, the computation and communication requirements are highest in the neighborhood of the sink. Thus, the third contribution of this thesis is a virtual nodes-based and energy efficient sensors deployment strategy for LWSN. Compared to a uniform deployment, this deployment improves the network lifetime by 40%. In our intersection monitoring application, it is important to correlate the messages generated by a sensor to its position with respect to the intersection. Therefore,the fourth contribution of this thesis is, a centroid-based algorithm for sensors ranking in a LWSN. We evaluate the performance of this algorithm considering a realistic channel model, a uniform deployment, as well as the virtual nodes based-deployment proposed in this thesis. Finally, putting all our contributions together, simulations show that WARIM can be used for reliable and real-time vehicular traffic monitoring at an intersection.Dans plusieurs pays à travers le monde, à cause des moyens financiers qui sont le plus souvent limités, la croissance des infrastructures de transport est généralement faible comparée non seulement à celle de la populations en zone urbaine, mais aussi à celle du parc automobile. Un tel contexte ne rend pas la tâche facile aux autorités en charge de la gestion des systèmes de transport. L'introduction des technologies de l'information et de la communication a permis à ces autorités de mieux adresser ce problème. Dans les centres urbains, la gestion du trafic véhiculaire aux intersections à un impact sur la congestion dans toute la ville. Dans cette thèse, notre objectif est de proposer une architecture de réseau de capteurs sans fil pour mesurer le trafic véhiculaire aux intersections. L'architecture proposée doit non seulement avoir un coût financier raisonnable, mais doit également être légère et autonome. Les architectures proposées dans la littérature utilisent des capteurs déployés sous la chaussée. D'un point de vu communication réseau, ces architectures sont irréalistes. La première contribution de cette thèse est la caractérisation des liens radio dans un réseau avec des capteurs déployés en surface du sol. Les résultats montrent un lien radio de mauvaise qualité au sol. Partant des conclusions de ce premier travail, la seconde contribution de cette thèse est WARIM, une nouvelle architecture de réseau de capteurs sans fil pour le monitoring du trafic véhiculaire au niveau des intersections. Dans WARIM, les capteurs déployés sur une voie forment un réseaux de capteurs sans fil, multi saut et ayant une topologie physique linéaire. Dans ce réseau, toutes les données sont relayées en direction d'un même point de collecte. Dans un tel réseau, les besoins en terme de traitement et de communication sont plus élevés dans le voisinage du point de collecte. Ainsi, la troisième contribution de cette thèse est, considérant un réseau de capteur linéaire, une stratégie de déploiement des capteurs basée sur le concept de noeuds virtuelles. Comparée a` un déploiement uniforme, la solution que nous proposons prolonge la durée de vie du réseau de l'ordre de 40%. Dans l'application de monitoring du trafic véhiculaire considérée dans cette thèse, il est important de corréler les messages générés par un capteur à sa position. La quatrième contribution de cette thèse est, considérant un réseau de capteur linéaire, un algorithme de classement des capteurs basé sur la centroide. Nous évaluons les performances de cet algorithme en considérant un modèle de communication réaliste, un déploiement uniforme, et aussi le déploiement proposé dans cette thèse. Finalement, en mettant ensemble toutes nos contributions, des simulations montrent que WARIM, l'architecture que nous avons proposée dans cette thèse, peut être utilisée pour une collecte fiable et en temps réel du trafic véhiculaire au niveau d'une intersection

Discours féminin ou féministe ? (une étude des oeuvres sélectionnées de Flora Nwapa et de Buchi Emecheta)

La problématique de ce travail de recherche repose sur la nature du discours qui émerge des oeuvres de Flora Nwapa et de Buchi Emecheta, deux écrivains d'origine nigériane. La lecture de One Is Enough et Women Are Different de Nwapa d'une part, et de The Joys of Motherhood et Second Class Citizen d'Emecheta d'autre part, véhicule en effet un message implicite et dévoile la femme noire africaine sous l'emprise d'un quotidien plutôt oppresseur. En resituant ces oeuvres dans les contextes socioculturel et littéraire africains, et en analysant les procédés rhétoriques et narratologiques utilisés par ces écrivaines, on parvient à donner une identité spécifique à la revendication féministe de leurs romans. Enfin, une analyse de la possible existence d'une écriture spécifique aux femmes chez Nwapa et Emecheta est effectuée à la lumière de la théorie de "l'écriture féminine" d'Hélène Cixous.NANCY2-BU Lettres (543952103) / SudocSudocFranceF

Discours féminin ou féministe ? : eune étude des oeuvres sélectionnées de Flora Nwapa et de Buchi Emecheta

This study examines the nature of the discourse to be found in the novels of Flora Nwapa and Buchi Emecheta, two Nigerian writers. On reading Nwapa's One Is Enough and Woman Are Different and Emecheta's The Joys of Motherhood and Second Class Citizen, we find that they do, indeed, convey an implicit message and that they show the black African woman subject to rather oppressive daily circumstances. By placing these novels within their African socio-cultural and literary contexts and by analysing the rhetorical and narratological tools used by these women writers, a specific identity can be given to the feminist claims of their novels. Finally, the possible existence of a specifically feminine writing in Nwapa and Emecheta's novels is discussed in the light of Hélène Cixous' theory of "écriture féminine".La problématique de ce travail de recherche repose sur la nature du discours qui émerge des oeuvres de Flora Nwapa et de Buchi Emecheta, deux écrivains d'origine nigériane. La lecture de One Is Enough et Women Are Different de Nwapa d'une part, et de The Joys of Motherhood et Second Class Citizen d'Emecheta d'autre part, véhicule en effet un message implicite et dévoile la femme noire africaine sous l'emprise d'un quotidien plutôt oppresseur. En resituant ces oeuvres dans les contextes socioculturel et littéraire africains, et en analysant les procédés rhétoriques et narratologiques utilisés par ces écrivaines, on parvient à donner une identité spécifique à la revendication féministe de leurs romans. Enfin, une analyse de la possible existence d'une écriture spécifique aux femmes chez Nwapa et Emecheta est effectuée à la lumière de la théorie de "l'écriture féminine" d'Hélène Cixous