10 research outputs found
Silencing of Vlaro2 for chorismate synthase revealed that the phytopathogen Verticillium longisporum induces the cross-pathway control in the xylem
The first leaky auxotrophic mutant for aromatic amino acids of the near-diploid fungal plant pathogen Verticillium longisporum (VL) has been generated. VL enters its host Brassica napus through the roots and colonizes the xylem vessels. The xylem contains little nutrients including low concentrations of amino acids. We isolated the gene Vlaro2 encoding chorismate synthase by complementation of the corresponding yeast mutant strain. Chorismate synthase produces the first branch point intermediate of aromatic amino acid biosynthesis. A novel RNA-mediated gene silencing method reduced gene expression of both isogenes by 80% and resulted in a bradytrophic mutant, which is a leaky auxotroph due to impaired expression of chorismate synthase. In contrast to the wild type, silencing resulted in increased expression of the cross-pathway regulatory gene VlcpcA (similar to cpcA/GCN4) during saprotrophic life. The mutant fungus is still able to infect the host plant B. napus and the model Arabidopsis thaliana with reduced efficiency. VlcpcA expression is increased in planta in the mutant and the wild-type fungus. We assume that xylem colonization requires induction of the cross-pathway control, presumably because the fungus has to overcome imbalanced amino acid supply in the xylem
Delay Tolerant Revocation Scheme for Delay Tolerant VANETs (DTRvS)
This article discusses an effective revocation scheme for disconnected Delay Tolerant Vehicular Ad hoc Networks (VANETs). Malicious vehicles can exhibit various misbehaviour such as dropping packets due to selfish reasons. Selfishness can be due to the need to conserve limited resources such as energy and bandwidth. This forces vehicles to either drop all or some of the packets they receive. This is particularly obtainable in multi-hop forwarding networks where packets are routed from one vehicle to another towards their destination. When some packets are dropped, the usefulness of the system is not fully realised since it affects the quality of information available to vehicles for making driving decisions such as road manoeuvres. Additionally, packet dropping can degrade the routing efficiency of the system. In extreme cases of misbehaviour, it is important to stop such vehicles from further participation in network communication. One way of achieving this is through revocation. However, it is important to establish mechanisms for identifying such vehicles before blacklisting them for revocation. Our objective here is to address the question of how much we can use a trust-based scheme where vehicles cannot always be expected to follow normal protocols for revocation. Revocation or suspension of misbehaving vehicles is essential to avoid havoc and possible economic damage
Spatial–temporal correlation dimension reduction and unsteady granger driving factor in regional varied earth surface in GIS
Routing in Post-Disaster Scenarios
Current networks should provide disaster-resilience by coping with the possible failures and misbehaviours caused by massive natural or man-made disasters. This is necessary to keep a suitable level of Quality of Service after a disaster and to support the possible evacuation, rescue, assessment, and rescue operations within the affected area. Multiple possible methods and solutions can be put in place in a proactive and/or reactive manner to offer the required resilience degree. Among them, a proper routing algorithm can contribute to circumventing network elements damaged by the disaster or applying for spatial/temporal redundancy to guarantee effective communications. This chapter aims at presenting the main routing solutions to offer disaster-resilience communications, along with some related methods
TPSense: A Framework for Event-Reports Trustworthiness Evaluation in Privacy-Preserving Vehicular Crowdsensing Systems
Automated valet parking and charging for e-mobility
Automated valet parking services provide great potential to increase the attractiveness of electric vehicles by mitigating their two main current deficiencies: reduced driving ranges and prolonged refueling times. The European research project V-Charge aims at providing this service on designated parking lots using close-to-market sensors only. For this purpose the project developed a prototype capable of performing fully automated navigation in mixed traffic on designated parking lots and GPS-denied parking garages with cameras and ultrasonic sensors only. This paper summarizes the work of the project, comprising advances in network communication and parking space scheduling, multi-camera calibration, semantic mapping concepts, visual localization and motion planning. The project pushed visual localization, environment perception and automated parking to centimetre precision. The developed infrastructure-based camera calibration and semi-supervised semantic mapping concepts greatly reduce maintenance efforts. Results are presented from extensive month-long field tests