Security architecture for vehicular communication

Abstract — Despite recent progress for vehicular communication in research, development, field tests, and standardization, security is still in an early phase though it represents a crucial part of the vehicular communication system. So far, no vehicular security architecture has been proposed which integrates existing individual solutions for vehicle registration, data integrity, authentication, and so on. By description of different architectural perspectives, we identify the stakeholders and their responsibilities. Then, we focus on the functional layer view and highlight the concepts which jointly secure the vehicular communication. Based on these concepts, we present an implementation approach which introduces the security concepts into the protocol stack of a vehicular communication system. The proposed security architecture follows a clean and modular design. It is the basis for our prototype implementation which will serve as a proof-of-concept. We will also submit this architecture to the ongoing standardization process of the Car2Car Communication Consortium (C2C-CC). I

Car-2-Car Communication Consortium - Manifesto

This document summarizes and describes the main building blocks of the Car2X Communication System as it is pursued by the Car2Car Communication Consortium (C2C-CC). “Car2X” means interactions among cars, between cars and infrastructures, and viceversa. It provides interested readers with an introduction to Car2X communications. It is intended to be a living document which will be complemented according to the progress of the work of the C2C-CC. One main objective of this document is to give insight into ongoing and upcoming activities, such as public funded projects which target to contribute to the C2C-CC specifications, an overview on ongoing work and results achieved so far. In addition, this document provides concepts and technologies that have been developed or identified by the C2C-CC and assessed as necessary building blocks to be proposed for a standard

Thoughts on a Protocol Architecture for Vehicular Ad-hoc Networks

Abstract — In comparison to other communication networks, Vehicular Ad-hoc Networks (VANETs) have unique requirements with respect to applications, types of communication, self-organization and other issues. In order to meet these requirements, the structuring of functionalities into protocols and their interaction must be re-thought. The traditional approach of decomposition of functionality into protocol layers (layered approach) and a protocol design specifically tailored to the needs of VANETs (un-layered approach) leads to two extreme and opposed manifestations of a potential VANET protocol architecture. From these two extreme approaches we derive a stack-based VANET protocol architecture that combines the strengths of both. Among the key features of this protocol architecture are VANET-specific protocol layers, a staircase approach for interaction among layers, and the use of an information connector for the exchange of cross-layer information using the publisher/subscriber pattern. This protocol architecture provides a clear modular structure with flexibility for protocol interaction and information exchange at a reasonable complexity. I

Interspecies variation of outer retina and choriocapillaris imaged with optical coherence tomography

Purpose: The purpose of this study is to assess with spectral-domain optical coherence tomography (OCT) the interspecies variation of outer retinal morphology and identification of choriocapillaris in four research animal species. Methods: Spectralis HRA+OCT images acquired from locations dorsal, central, and ventral to the optic disc in healthy, anesthetized animals were evaluated by two independent readers. First, the number of OCT B-scans on which a choriocapillaris layer could clearly be identified was determined and quantified, and B-scans were correlated with histology. Second, B-scans demonstrating the highest number of discernable individual outer retinal bands (ORBs) were defined as ideal presentation and quantified. Interrater agreement was evaluated. Results: Five-hundred seventy-four B-scans from 96 subjects were evaluated. The choriocapillaris layer was identified in 100.0% of minipig, 70.8% of rabbit, 75.4% of pigmented rat, 77.7% of albino rat, 56.5% of pigmented mouse, and 50.8% of albino mouse OCT scans. The percentage of ideal ORB presentation in B-scans was 11.7% in minipigs, 73.8% in rabbits, and 80.0%, 91.0%, 28.5%, and 62.5% in pigmented rats and mice and albino rats and mice, respectively. The interrater evaluation for both attributes showed substantial to perfect agreement in all species. Conclusions: The choriocapillaris is an easy and valid marker for identification of the outer retinal margin. ORB presentation likely varies due to differences in retinal anatomy and pigmentation between animal species and strains and between anatomic locations. Proper and consistent outer retinal margin and ORB identification are essential for research result reproducibility and translation

Communication Technologies for Vehicles

The Communication Technologies for Vehicles workshop series provides an international forum on latest technologies and research in the field of intra- and inter-vehicle communications in which to present original research results in all areas relating to communication protocols and standards, mobility and traffic models, experimental and field operational testing, and performance analysis

Retinol initiated poly(lactide) s: stability upon polymerization and nanoparticle preparation

The synthesis of retinol initiated polylactide (PLA) by ring opening polymerization (ROP) of L-lactide via in situ calcium alkoxide formation with all-trans-retinol and Ca[N(SiMe3)(2)](2)(THF)(2) is described. PLAs with degree of polymerization (DP) values ranging from 13 to 60 were obtained and characterized in detail by means of H-1 nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), UV/vis spectroscopy and (tandem) mass spectrometry techniques. Stable nanoparticles (NPs) were prepared via a nanoprecipitation method and characterized by DLS and SEM. The stability of retinol upon conjugation to PLA as well as the nanoparticle formulation was investigated in detail and found to be significantly affected by the storage conditions such as exposure to light, oxygen and temperature

Safety, tissue distribution, and metabolism of LNA-containing antisense oligonucleotides in rats

Antisense oligonucleotides (ASOs) are chemically modified nucleic acids with therapeutic potential, some of which have been approved for marketing. We performed a study in rats to investigate mechanisms of toxicity after administration of 3 tool locked nucleic acid (LNA)-containing ASOs with differing established safety profiles. Four male rats per group were dosed once, 3, or 6 times subcutaneously, with 7 days between dosing, and sacrificed 3 days after the last dose. These ASOs were either unconjugated (naked) or conjugated with N-acetylgalactosamine for hepatocyte-targeted delivery. The main readouts were in-life monitoring, clinical and anatomic pathology, exposure assessment and metabolite identification in liver and kidney by liquid chromatography coupled to tandem mass spectrometry, ASO detection in liver and kidney by immunohistochemistry, in situ hybridization, immune electron microscopy, and matrix-assisted laser desorption/ionization mass spectrometry imaging. The highly toxic compounds showed the greatest amount of metabolites and a low degree of tissue accumulation. This study reveals different patterns of cell death associated with toxicity in liver (apoptosis and necrosis) and kidney (necrosis only) and provides new ultrastructural insights on the tissue accumulation of ASOs. We observed that the immunostimulatory properties of ASOs can be either primary from sequence-dependent properties or secondary to cell necrosis

Inhibition of EGF Uptake by Nephrotoxic Antisense Drugs In Vitro and Implications for Preclinical Safety Profiling

Antisense oligonucleotide (AON) therapeutics offer new avenues to pursue clinically relevant targets inaccessible with other technologies. Advances in improving AON affinity and stability by incorporation of high affinity nucleotides, such as locked nucleic acids (LNA), have sometimes been stifled by safety liabilities related to their accumulation in the kidney tubule. In an attempt to predict and understand the mechanisms of LNA-AON-induced renal tubular toxicity, we established human cell models that recapitulate in vivo behavior of pre-clinically and clinically unfavorable LNA-AON drug candidates. We identified elevation of extracellular epidermal growth factor (EGF) as a robust and sensitive in vitro biomarker of LNA-AON-induced cytotoxicity in human kidney tubule epithelial cells. We report the time-dependent negative regulation of EGF uptake and EGF receptor (EGFR) signaling by toxic but not innocuous LNA-AONs and revealed the importance of EGFR signaling in LNA-AON-mediated decrease in cellular activity. The robust EGF-based in vitro safety profiling of LNA-AON drug candidates presented here, together with a better understanding of the underlying molecular mechanisms, constitutes a significant step toward developing safer antisense therapeutics. Keywords: kidney, nephrotoxicity, EGF, EGFR, PTEC, antisense, oligonucleotide, safety, preclinica