71 research outputs found
Development of new PCR primers by comparative genomics for the detection of Helicobacter suis in gastric biopsy specimens
Background: Although the infection rate of Helicobacter suis is significantly lower than that of Helicobacter pylori, the H. suis infection is associated with a high rate of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In addition, in vitro cultivation of H. suis remains difficult, and some H. suis-infected patients show negative results on the urea breath test (UBT).
Materials and Methods: Female C57BL/6J mice were orally inoculated with mouse gastric mucosal homogenates containing H. suis strains TKY or SNTW101 isolated from a cynomolgus monkey or a patient suffering from nodular gastritis, respectively. The high-purity chromosomal DNA samples of H. suis strains TKY and SNTW101 were prepared from the infected mouse gastric mucosa. The SOLiD sequencing of two H. suis genomes enabled comparative genomics of 20 Helicobacter and 11 Campylobacter strains for the identification of the H. suis-specific nucleotide sequences.
Results: Oral inoculation with mouse gastric mucosal homogenates containing H. suis strains TKY and SNTW101 induced gastric MALT lymphoma and the formation of gastric lymphoid follicles, respectively, in C57BL/6J mice. Two conserved nucleotide sequences among six H. suis strains were identified and were used to design diagnostic PCR primers for the detection of H. suis.
Conclusions: There was a strong association between the H. suis infection and gastric diseases in the C57BL/6 mouse model. PCR diagnosis using an H. suis-specific primer pair is a valuable method for detecting H. suis in gastric biopsy specimens
A Comprehensive Approach to WSN-Based ITS Applications: A Survey
In order to perform sensing tasks, most current Intelligent Transportation Systems (ITS) rely on expensive sensors, which offer only limited functionality. A more recent trend consists of using Wireless Sensor Networks (WSN) for such purpose, which reduces the required investment and enables the development of new collaborative and intelligent applications that further contribute to improve both driving safety and traffic efficiency. This paper surveys the application of WSNs to such ITS scenarios, tackling the main issues that may arise when developing these systems. The paper is divided into sections which address different matters including vehicle detection and classification as well as the selection of appropriate communication protocols, network architecture, topology and some important design parameters. In addition, in line with the multiplicity of different technologies that take part in ITS, it does not consider WSNs just as stand-alone systems, but also as key components of heterogeneous systems cooperating along with other technologies employed in vehicular scenarios
Performance evaluation of Vehicular Ad Hoc Networks over high speed environment using NCTUns
CatalĂ : Cada any aproximadament un miliĂł dues-centes mil persones moren en accidents de trĂ nsit. D'aquesta dada es desprèn que els accidents de trĂ nsit sĂłn la quarta causa de mortalitat al mĂłn. Degut a això, un gran nombre de governs i els majors fabricants de vehicles del mĂłn estan invertint temps i diners en recerca i desenvolupament per millorar la seguretat a les carreteres. Amb aquest objectiu, apareix el concepte de VANET: Vehicular Ad-hoc NETwork. Una VANET estĂ basada en vehicles i estacions base intel·ligents que comparteixen informaciĂł a travĂ©s de comunicacions inalĂ mbriques. Aquest intercanvi de dades podria tenir un gran impacte en la seguretat viĂ ria i la qualitat en la conducciĂł però a mĂ©s a mĂ©s seria una nova font d' entreteniment mòbil. La millora en seguretat implicaria una reducciĂł en el nombre d'accidents i les comunicacions inalĂ mbriques usades en mobilitat permetrien una optimitzaciĂł del transport. L'evoluciĂł de les VANETs en els Ăşltims anys i les seves aplicacions Ăştils a les carreteres sĂłn les principals raons per dur a terme aquest projecte. El gran suport a aquest tipus de xarxes inalĂ mbriques sembla indicar que les VANETs sĂłn les xarxes del futur en entorns mòbils. En relaciĂł al projecte, el primer problema observat Ă©s que el protocol que s'usa especĂficament en VANETs (802.11p) nomĂ©s estĂ disponible en pocs simuladors de xarxa i estĂ en fase de desenvolupament. Per tant, la majoria de les funcions no estan implementades i això fa que el protocol no sigui madur. En conseqüència, es va triar un protocol Ă mpliament usat com Ă©s 802.11b per fer les proves en el simulador NCTUns. L?objectiu del projecte Ă©s avaluar el funcionament de VANETs usant el protocol 802.11b i el protocol d?encaminament AODV en un escenari d?autopista. Ajustant diferents parĂ metres com el nombre de cotxes, la seva velocitat i el seu rang de cobertura Ă©s possible obtenir variacions en les mesures de pèrdues, throughput i retard extrem-a-extrem en la xarxa. El resultat final Ă©s que les mesures permeten saber quines sĂłn les comunicacions que es produeixen a la xarxa per cadascuna de les configuracions i la seva incidència en les condicions de conducciĂł.Castellano: Cada año cerca de un millĂłn doscientas mil personas fallecen en accidentes de tráfico. De este dato se desprende que los accidentes de tráfico son la cuarta causa de mortalidad en el mundo. Debido a esto, un gran nĂşmero de gobiernos y los mayores fabricantes de vehĂculos del mundo están invirtiendo tiempo y dinero en investigaciĂłn y desarrollo para mejorar la seguridad en las carreteras. Con este objetivo, aparece el concepto de VANET: Vehicular Ad-hoc NETwork. Una VANET se basa en vehĂculos y estaciones base inteligentes que comparten informaciĂłn por medio de comunicaciones inalámbricas. Este intercambio de datos podrĂa tener un gran impacto en la seguridad vial y en la calidad de la conducciĂłn pero además serĂa una nueva fuente de entretenimiento mĂłvil. La mejora en la seguridad implicarĂa una reducciĂłn en el nĂşmero de accidentes y las comunicaciones inalámbricas utilizadas en movilidad permitirĂan optimizar el transporte. La evoluciĂłn de las VANETs en los Ăşltimos años y sus aplicaciones Ăştiles en las carreteras son las principales razones para llevar a cabo este proyecto. El gran apoyo a este tipo de redes inalámbricas parece indicar que las VANETs son las redes del futuro en entornos mĂłviles. En relaciĂłn al proyecto, el primer problema observado es que el protocolo especĂficamente utilizado en VANETs (802.11p) sĂłlo está disponible en pocos simuladores de red y se encuentra en fase de desarrollo. Por lo tanto, la mayorĂa de funciones no están implementadas y esto hace que el protocolo no sea maduro. En consecuencia, se escogiĂł un protocolo ampliamente utilizado como es 802.11b para realizar las pruebas en el simulador NCTUns. El objetivo del proyecto es evaluar el funcionamiento de VANETs utilizando el protocolo 802.11b y el protocolo de encaminamiento AODV en un escenario de autopista. Ajustando diferentes parámetros como el nĂşmero de coches, su velocidad y su rango de cobertura es posible obtener variaciones en las medidas de pĂ©rdidas, throughput y retardo extremo-a-extremo en la red. El resultado final es que las medidas permiten saber cuáles son las comunicaciones que se producen en la red para cada una de las configuraciones y su incidencia en las condiciones de conducciĂłn.English: Every year about 1.2 million people die because of traffic accidents [1]. This means that traffic accidents are the fourth cause of mortality in the world. Therefore, several governments and the most important car manufacturers are investing time and money on research and development in order to improve road safety. At this respect, appears the concept of VANET: Vehicular Ad-hoc NETwork. A VANET is based on smart cars and base-stations that share information via wireless communications. This interchange of data may have a great impact on safety and driving quality but also could be another source of mobile entertainment. This improvement on safety would imply reducing the number of accidents. In addition, the use of wireless communications in mobility would lead to an optimization of transport. The evolution of VANETs in the last years and their useful applications on the road has been the main reason to develop this project. The great support of many people to this type of wireless networks suggests that VANETs are the networks of the future in mobile environments. Regarding the project, the first problem encountered is that the network protocol specially designed for VANETs, IEEE 802.11p, is only available in a few of the network simulators and is on phase of development. This fact means that most of the functions are not implemented so it cannot be considered as a mature protocol. As a consequence, a widely used protocol as IEEE 802.11b was chosen and all the tests were performed on NCTUns simulator. So the purpose of this project is to evaluate the performance of VANETs by using 802.11b protocol and AODV routing protocol in a highway scenario. By adjusting different parameters like number of cars, their speed and their range of coverage, variations on measures of loss ratio, throughput and end-to- end delay were detected on the network. Finally, the measures help to know about network communications for each of the cases and their incidence on driving conditions
Design and implementation of an ITS station to bridge automotive and IoT systems
This thesis is about the development of a software package for on-board and road side devices in Intelligent Transport Systems. Such a software implements the stack of an ITS station as standardized by ETSI. The main innovation relies in the integration of an IoT segment based on IETF standards for wireless constrained devices. Prototyped hardware and software are being adopted and field tested in the URBELOG project focusing on last mile logistics in smart cities
Analysis of current and potential sensor network technologies and their incorporation as embedded structural system
This document provides a brief overview of the actual wireless ad hoc sensor networks technologies and standards available, especially in view of their possible implementation for shipping container protection and monitoring within the framework of the STEC Action aiming at analyzing possible technical solutions to improve the security of the millions of containers moving in and out of Europe. Examples of applications and research projects are reported from the literature to give insights on the possibility of implementation of wireless sensor networks in real world scenarios.JRC.G.5-European laboratory for structural assessmen
Wireless Technologies for IoT in Smart Cities
[EN] As cities continue to grow, numerous initiatives for Smart Cities are being conducted. The
concept of Smart City encompasses several concepts being governance, economy,
management, infrastructure, technology and people. This means that a Smart City can have
different communication needs. Wireless technologies such as WiFi, ZigBee, Bluetooth,
WiMax, 4G or LTE (Long Term Evolution) have presented themselves as solutions to the
communication needs of Smart City initiatives. However, as most of them employ unlicensed
bands, interference and coexistence problems are increasing. In this paper, the wireless
technologies available nowadays for IoT (Internet of Things) in Smart Cities are presented.
Our contribution is a review of wireless technologies, their comparison and the problems that
difficult coexistence among them. In order to do so, the characteristics and adequacy of
wireless technologies to each domain are considered. The problems derived of over-crowded
unlicensed spectrum and coexistence difficulties among each technology are discussed as
well. Finally, power consumption concerns are addressed.GarcĂa-GarcĂa, L.; Jimenez, JM.; Abdullah, MTA.; Lloret, J. (2018). Wireless Technologies for IoT in Smart Cities. Network Protocols and Algorithms. 10(1):23-64. doi:10.5296/npa.v10i1.12798S236410
Survey on RPL enhancements: a focus on topology, security and mobility
International audienceA few years ago, the IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was proposed by IETF as the routing standard designed for classes of networks in which both nodes and their interconnects are constrained. Since then, great attention has been paid by the scientific and industrial communities for the protocol evaluation and improvement. Indeed, depending on applications scenarios, constraints related to the target environments or other requirements, many adaptations and improvements can be made. So, since the initial release of the standard, several implementations were proposed, some targeting specific optimization goals whereas others would optimize several criteria while building the routing topology. They include, but are not limited to, extending the network lifetime, maximizing throughput at the sink node, avoiding the less secured nodes, considering nodes or sink mobility. Sometimes, to consider the Quality of Service (QoS), it is necessary to consider several of those criteria at the same time. This paper reviews recent works on RPL and highlights major contributions to its improvement, especially those related to topology optimization, security and mobility. We aim to provide an insight into relevant efforts around the protocol, draw some lessons and give useful guidelines for future developments
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