1,721,064 research outputs found
Vehicular networking for safety and infotainment services: An heterogeneous approach to Intelligent Transport Systems
No full textIn the recent years, Intelligent Transportation Systems (ITS) have been getting more and more integrated in the everyday commuter experience. Besides this trend, technology in this area is evolving very slowly and it is sometimes outdated. Vehicular ad-hoc Networks (VANET) have been emerging as a more and more useful technology, able to provide significant support to ITS, although they are in a preliminary stage, yet.
VANETs allow the possibility to communicate from a vehicle to another vehicle (V2V, Vehicle to Vehicle) and from any Vehicle to the Infrastructure (V2I), thus leading to a naturally suited architecture for geo-localised communication, which well adapts to ITS.
In this thesis, VANETs are applied to ITS in a unique and distributed approach that involves all the communication layers and investigates to what extent ITS can be improved by using innovative technologies used in combination with existing networking technologies like 3G or LTE in an heterogeneous approach. The philosophy behind this work is to explore and innovate Vehicular Networking in every aspect, thus leading to an all-round approach. This thesis, in facts, investigates the application layer, the routing layer and it proposes new real world heterogeneous and VANET experiments.
At the application layer, the author explains the creation of a safety and control application to perform real-time vehicular traffic monitoring; the application layer is completed by another application related to infotainment and service channels, to share real-time videos in car incident scenarios or road condition monitoring scenarios. Below the application layer, this thesis proposes new VANET routing protocols to increase efficiency and throughput according to different approaches; how the information travels from sensors in a car to the network is also investigated. Finally the author has realised several real world experiments and heterogeneous applications that use the knowledge and the proposed innovations acquired from the Intelligent Transportation systems exploration and put them into practice. The all-round approach of this work, in facts, totally embraces ITS and such vision represents a complete approach aimed at showing how and where it is possible to improve ITS, from innovative theory to experimental practice
Thyroid development and its disorders:genetics and molecular mechanisms
No full textThyroid gland organogenesis results in an organ the shape, size, and position of which are largely conserved among adult individuals of the same species, thus suggesting that genetic factors must be involved in controlling these parameters. In humans, the organogenesis of the thyroid gland is often disturbed, leading to a variety of conditions, such as agenesis, ectopy, and hypoplasia, which are collectively called thyroid dysgenesis (TD). The molecular mechanisms leading to TD are largely unknown. Studies in murine models and in a few patients with dysgenesis revealed that mutations in regulatory genes expressed in the developing thyroid are responsible for this condition, thus showing that TD can be a genetic and inheritable disease. These studies open the way to a novel working hypothesis on the molecular and genetic basis of this frequent human condition and render the thyroid an important model in the understanding of molecular mechanisms regulating the size, shape, and position of organs
Vehicular ad-hoc networks sampling protocols for traffic monitoring and incident detection in intelligent transportation systems
No full textVehicular Ad-Hoc Networks (VANETs) are an emerging technology soon to be brought to everyday life. Many Intelligent Transport Systems (ITS) services that are nowadays performed with expensive infrastructure, like reliable traffic monitoring and car accident detection, can be enhanced and even entirely provided through this technology. In this paper, we propose and assess how to use \{VANETs\} for collecting vehicular traffic measurements. We provide two \{VANET\} sampling protocols, named \{SAME\} and TOME, and we design and implement an application for one of them, to perform real time incident detection. The proposed framework is validated through simulations of both vehicular micro-mobility and communications on the 68 km highway that surrounds Rome, Italy. Vehicular traffic is generated based on a large real \{GPS\} traces set measured on the same highway, involving about ten thousand vehicles over many days. We show that the sampling monitoring protocol, SAME, collects data in few seconds with relative errors less than 10%, whereas the exhaustive protocol \{TOME\} allows almost fully accurate estimates within few tens of seconds. We also investigate the effect of a limited deployment of the \{VANET\} technology on board of vehicles. Both traffic monitoring and incident detection are shown to still be feasible with just 50% of equipped vehicles
Minireview: thyrotropin receptor signaling in development and differentiation of the thyroid gland: insights from mouse models and human diseases.
No full text
The transcription factor TTF-1 is expressed at the onset of thyroid and lung morphogenesis and in restricted regions of the foetal brain.
No full textTTF-1, a homeodomain-containing transcription factor, which is required for the specific expression of the thyroglobulin and thyroperoxidase gene promoters in differentiated thyroid cell lines, is expressed at the very beginning of rat thyroid differentiation. TTF-1 mRNA is detected in the endodermal cells of the thyroid rudiment in the rat embryo and precedes the expression of the two known target genes by 5 days. No delay is observed between the appearance of TTF-1 mRNA and protein, which shows a clear nuclear localization. In the adult thyroid, TTF-1 is present only in the endoderm-derived follicular cells. Two additional domains of expression of TTF-1 have been observed, the lung and restricted areas of the brain. In the lung, TTF-1 mRNA and protein are also present at the earliest stages of differentiation and are later confined to the bronchial epithelium. In the brain, TTF-1 appears to be restricted to structures of diencephalic origin, including the developing neurohypophysis. The early detection of TTF-1 in the endodermal cells of the thyroid and lung anlage and in restricted neuroblast populations indicates that TTF-1 may have a role in cell determination in these three systems and that additional mechanisms may be involved in the activation of thyroid-specific gene expression
Murine models for the study of thyroid gland development.
No full textGene targeting technology has allowed the generation of mouse mutants which lack specific genes. These mice represent a valuable tool for identifying the in vivo functions of proteins and for dissecting the pathways that control the development and differentiation of the numerous structures of the body. What we know about thyroid morphogenesis is largely due to studies on murine models generated in gene-targeting experiments. Although several points remain to be elucidated, a number of genes involved in thyroid organogenesis have been identified in recent years. In addition, this information has greatly improved our knowledge of the pathogenetic mechanisms of thyroid dysgenesis in humans. This review summarizes the complex processes leading to thyroid development mostly by describing the phenotype of currently available knockout animals
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