1,601 research outputs found

    Chilopodes cavernicoles et endogés de l'île de Majorque.

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    In the last years we have witnessed a boom in the use of techniques and tools that provide anonymity. Such techniques and tools are used by clients that want their communication to stay anonymous or to access censored content, as well as by administrators to hide the location of their servers. All those activities can be easily performed with the support of an anonymity network. An important component of an anonymity network is the hidden server, a machine whose IP address is kept secret. Such hidden servers are the target of research in this thesis. More specifically, we focus on different types of hidden servers used in the Tor anonymity network. Tor hidden services (HSes) are anonymous services hosted in the Tor Network. The HS itself is a hidden server because users that connect to it are not aware of its IP address, and thus its location. Another equally important kind of hidden servers are Tor bridges. Bridges are entry nodes of the Tor Network, whose IP address is not publicly disclosed to avoid blocking traffic towards them. Bridges are meant to be used by clients that connect from countries where governments perform selective filtering over the contents that users can access, and for this reason governments try to block connections to those nodes. In this thesis we develop novel approaches and we implement them into techniques to analyze the security and reveal the location of hidden servers. This thesis comprises two parts, one dealing with HSes and the other one with bridges. In the first part of the thesis, we develop a novel active approach for recovering the IP address of hidden servers that are used for hosting HSes. To this end, we design, implement, and evaluate a tool called Caronte that explores the content and configuration of a hidden service to automatically identify location leaks. Later those leaks are leveraged for trying to unveil the IP address of the hidden service. Our approach differs from previous ones, because Caronte does not rely on flaws in the Tor protocol and assumes an open-world model, i.e., it does not require a list of candidate servers known in advance. A final validation iistep guarantees that all the candidates that are false positives (i.e., they are not hosting the hidden service) are discarded. We demonstrate Caronte by running it on real HSes and successfully deanonymizing over 100 of them. In the second part of the thesis we perform the first systematic study of the Tor bridge infrastructure. Our study covers both the public bridge infrastructure available to all Tor users, and the previously unreported private bridge infrastructure, comprising private nodes for the exclusive use of those who know about their existence. Our analysis of the public infrastructure is twofold. First, we examine the security implications of the public data accessible from the CollecTor service. This service collects and publishes detailed information and statistics about core elements of the Tor Network. Despite the fact that CollecTor anonymizes sensitive data (e.g., IP or emails of bridge owners) prior to its publication, we identify several pieces of information that may be detrimental for the security of public bridges. Then, we measure security relevant properties of public bridges, including their lifetime and how often they change IP and port. Our results show how the public bridge ecosystem with clients is stable and those bridges rarely change their IP address. This has consequences for the current blocking policies that governments are using to restrict access to the anonymity network, because more aggressive strategies could be adopted. We also show how the presence of multiple transport protocols could harm bridge anonymity (since the adversary becomes able to identify the bridge through the weakest protocol). To study the private bridge infrastructure, we use an approach to discover 694 private bridges on the Internet and a novel technique, that leverages additional services running on bridges, to track bridges across IP changes. During this process, we identify the existence of infrastructures that use private proxies to forward traffic to backend bridges or relays. Finally, we discuss the security implications of our findings

    The microRNA analysis portal is a next-generation tool for exploring and analyzing miRNA-focused data in the literature.

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    MicroRNAs constitute a class of noncoding small RNAs involved in the posttranscriptional regulation of many biological pathways. In recent years, microRNAs have also been associated with regulation across kingdoms, demonstrating that exogenous miRNAs can function in mammals in a fashion similar to mammalian miRNAs. The growing interest in microRNAs and the increasing amount of literature and molecular and biomedical data available make it difficult to identify records of interest and keep up to date with novel findings. For these reasons, we developed the microRNA Analysis Portal (MAP). MAP selects relevant miRNA-focused articles from PubMed, links biomedical and molecular data and applies bioinformatics modules. At the time of this writing, MAP represents the richest, most complete and integrated database focused on microRNAs. MAP also integrates an updated version of MirCompare (2.0), a computational platform used for selecting plant microRNAs on the basis of their ability to regulate mammalian genes. Both MAP and MirCompare functionalities were used to predict that microRNAs from Moringa oleifera have putative roles across kingdoms by regulating human genes coding for proteins of the immune system. Starting from a selection of 94 human microRNAs, MirCompare selected 6 Moringa oleifera functional homologs. The subsequent prediction of human targets and areas of functional enrichment highlighted the central involvement of these genes in regulating immune system processes, particularly the host-virus interaction processes in hepatitis B, cytomegalovirus, papillomavirus and coronavirus. This case of use showed how MAP can help to perform complex queries without any computational background. MAP is available at http://stablab.uniroma2.it/MAP

    A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling

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    The 18 kDa translocator protein TSPO localizes on the outer mitochondrial membrane (OMM). Systematically overexpressed at sites of neuroinflammation it is adopted as a biomarker of brain conditions. TSPO inhibits the autophagic removal of mitochondria by limiting PARK2-mediated mitochondrial ubiquitination via a peri-organelle accumulation of reactive oxygen species (ROS). Here we describe that TSPO deregulates mitochondrial Ca2+ signaling leading to a parallel increase in the cytosolic Ca2+ pools that activate the Ca2+-dependent NADPH oxidase (NOX) thereby increasing ROS. The inhibition of mitochondrial Ca2+ uptake by TSPO is a consequence of the phosphorylation of the voltage-dependent anion channel (VDAC1) by the protein kinase A (PKA), which is recruited to the mitochondria, in complex with the Acyl-CoA binding domain containing 3 (ACBD3). Notably, the neurotransmitter glutamate, which contributes neuronal toxicity in age-dependent conditions, triggers this TSPO-dependent mechanism of cell signaling leading to cellular demise. TSPO is therefore proposed as a novel OMM-based pathway to control intracellular Ca2+ dynamics and redox transients in neuronal cytotoxicity

    Detection of Parietaria Mottle Virus by RT-qPCR: An Emerging Virus Native of Mediterranean Area That Undermine Tomato and Pepper Production in Southern Italy

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    Parietaria mottle virus (PMoV) is considered an emerging virus in many countries of the Mediterranean basin, especially on tomato and pepper crops. Symptoms on tomato leaves and fruits can be easily confused with those induced by cucumber mosaic virus (CMV) with necrogenic satellite RNA (CMV-satRNA), tomato spotted wilt virus (TSWV) or tomato mosaic virus (ToMV). Mixed infection of these viruses has been also reported in some tomato cultivars, with an increase in the complexity of the symptoms and severity of the disease. Although a specific serum and riboprobes have been produced, nowadays no sensitive diagnostic methods are available for the rapid PMoV detection. Here, we have developed a RT-qPCR assay with the aim to establish a more sensitive and specific method for PMoV detection. Specific primers and TaqMan probe were designed and in silico tested with all PMoV isolates available in GenBank. Moreover, this method was evaluated on tomato naturally infected samples from Sicily region (Italy). Results obtained showed that the RT-qPCR assay developed in this work is extremely sensitive, in fact, it is able to detect as few as 10 PMoV RNA copies in tomato total RNA; moreover, it will be a particularly valuable tool for early detection of PMoV. Furthermore, the analyzes on field samples show how this pathogen is increasingly present in tomato crops in the last years, helping to undermine the Italian horticultural sector
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