A survey of V2V channel modeling for VANET simulations

International audienceMost Vehicle to Vehicle (V2V) network protocols are evaluated by simulation. However in most network simulators, the physical layer suffers from a lack of realism. Therefore, realistic V2V channel modeling has become a crucial issue in Intelligent Transportation Systems (ITS) networks. V2V channels are known to exhibit specific features which imply the design of new simulation models. In this survey paper, we first recall the main physical features of such wireless time and frequency dispersive channels. Next, three "simulation-ready" V2V channel models found in the literature are reviewed. Finally, two complete VANET simulation frameworks are presented. They illustrate the importance of a realistic channel and physical layer modeling in vehicular networking

A Two-Site Immunoradiometric Assay for Serum Calcitonin Using Monoclonal Anti-Peptide Antibodies

We have produced a library of monoclonal antibodies of various affinities by immunizing mice with synthetic calcitonin (CT) 1-32. These monoclonal antibodies defined two antigenic determinants on the molecule of CT. The first was located in the 11-17 region of the hormone: the second was present on the 26-32 portion of CT. The C-terminal epitope was restricted to the mature form of the hormone and immunologically silent on synthetic peptides with sequences analogous lo the biosynthetic precursors for CT. Using two high-affinity monoclonal antibodies, designated as CT07 and CT08, we developed a two-site immunoradiometric assay (m-lRMA) for serum CT. This m-lRMA provided a sensitivity of 10 pg/mL using a one-step overnight incubation at room temperature. Gel filtration analyses of serum samples from patients with medullary thyroid carcinoma (MTC) demonstrated that the CT07-CT08 m-lRMA was specific for the circulating mature form of CT

Impact of realistic simulation on the evaluation of mobile Ad-hoc routing protocols

International audienceToday’s advanced simulators facilitate thorough studies on vehicular ad hocnetworks (VANETs). However, the choice of the physical layer and the mobility models in such simulatorsis a crucial issue that greatly impacts the results. Realistic simulation of routing protocols in VANETs is stillan open question. Indeed, only a few works address routing protocols comparison performed under realisticconditions. This paper compares common reactive, proactive, hybrid, and geographic routing protocolsusing a simulation platform integrating a realistic physical layer and mobility models. It also presents andanalyzes several reactive protocol enhancement propositions dedicated to the VANETs context, such asmultipath routing, but also protocols tuning, which allows it to adapt faster. They all have lot of attentionand are typically proposed to increase the reliability of data transmission. This paper studies the behavior ofeach protocol in different situations and analyzed their advantages and drawbacks. Results presented in thispaper give an important explanation on the contradictory results found in similar works. Finally, our realisticsimulations show that reactive protocols are the best suited for VANETs, and more especially the dynamicMobile Adhoc NETwork on-demand protocol

Mechanisms of Azole Resistance in Petite Mutants of Candida glabrata

We previously showed that resistant colonies of Candida glabrata inside the azole inhibition zones had respiratory deficiency due to mutations in mitochondrial DNA. Here, we analyzed the mechanisms of azole resistance in petite mutants of C. glabrata obtained by exposure to fluconazole or induced by ethidium bromide. The respiratory deficiency of these mutants was confirmed by oxygraphy and flow cytometric analysis with rhodamine 123, and its mitochondrial origin was demonstrated by transmission electron microscopy and restriction endonuclease analysis of the mitochondrial DNA. Flow cytometry with rhodamine 6G suggested an increased drug efflux in mutant cells, which was further supported by Northern blot analysis of the expression of the C. glabrata CDR1 (CgCDR1) and CgCDR2 genes, encoding efflux pumps. Conversely, the expression of CgERG11, which encodes the azole target, was not affected by petite mutations, and no differences were seen in the sequence of this gene between parent isolates and mutants. Moreover, sterol analysis showed similar overall amount of sterols in parent and mutant cells, but quantitative modifications were observed in the mutants, with almost undetectable biosynthesis intermediates. Further analysis performed after separation of free sterols from steryl esters revealed a defect in sterol esterification in mutant cells, with free ergosterol representing 92% of the overall sterol content. Thus, resistance or decreased susceptibility to azoles in petite mutants of C. glabrata is associated with increased expression of CgCDR1 and, to a lesser extent, of CgCDR2. In addition, the marked increase in free ergosterol content would explain their increased susceptibility to polyenes

Personal protection against biting insects and ticks.

International audienceRecent events with the first cases of local transmission of chikungunya and dengue fever virus in southern France by Aedes albopictus, adding to the nuisance and potential vectors that can be encountered when traveling in tropical or sub-tropical countries, has shown the value of a reflection on the Personal protection against vectors (PPAV). It is seen during an outbreak of vector-borne disease, or simply because of nuisance arthropods, that our fellow citizens try to protect themselves individually by using an arsenal of resources available on the market. Yet most of these means have been neither checked for effectiveness or safety tests, however, essential. Travellers, staff on mission or assignment, are looking for specific information on how to protect themselves or their families. Health workers had at their disposal so far indications that vary widely from one source to another. Therefore it seemed important to the Society of Travel Medicine (SMV) and the French Society of Parasitology (SFP) to initiate a reflection on this theme. This reflection took the form of recommendations for good practice, following the outline established by the French High Health Authority (HAS). The aim was to gather all relevant information, verified and validated and the format to be used not only by health personnel (doctors, pharmacists, nurses), but also by travel agents and individuals. This document highlights the need to take into account the risk of vector-borne diseases, some deadly, and the benefit of various methods of personal protection. The choice of methods is clearly oriented towards those whose effectiveness has been proven and potential risks assessed. The paper finally proposes two decision trees based on the transmission type (day or night) and kind of stay (short or roaming, long and steady). It concerns travellers, but also expatriates, residents and nomads