389 research outputs found

    Evaluation of Anonymized ONS Queries

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    Electronic Product Code (EPC) is the basis of a pervasive infrastructure for the automatic identification of objects on supply chain applications (e.g., pharmaceutical or military applications). This infrastructure relies on the use of the (1) Radio Frequency Identification (RFID) technology to tag objects in motion and (2) distributed services providing information about objects via the Internet. A lookup service, called the Object Name Service (ONS) and based on the use of the Domain Name System (DNS), can be publicly accessed by EPC applications looking for information associated with tagged objects. Privacy issues may affect corporate infrastructures based on EPC technologies if their lookup service is not properly protected. A possible solution to mitigate these issues is the use of online anonymity. We present an evaluation experiment that compares the of use of Tor (The second generation Onion Router) on a global ONS/DNS setup, with respect to benefits, limitations, and latency.Comment: 14 page

    A Virtual Ground Station Based on Distributed Components for Satellite Communications

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    Communication with Low-Earth Orbit (LEO) satellites requires the set up of a ground station which is a complex and costly installation. Moreover, a LEO satellite is accessible only during certain time slots from a given ground station. In other words, access to LEO satellites is on an intermittent basis and is constrained by the availability of ground stations. The work presented in this paper aims at augmenting the accessibility to the services offered by LEO satellites. We have devised a concept of virtual ground station available over the Internet. A virtual ground station can be used by any client with a computer attached to the Internet which augments the degree of accessibility. Besides, a virtual ground station and its clients don\u27t have to be collocated. A client can access a satellite as long as a remote virtual ground station has access to it. As long as there are several virtual ground stations distributed at several locations, this architecture augments the degree of accessibility to satellites. The design of the virtual ground station is based on CORBA distributed components. The virtual ground station has been developed using an application framework we have created, hence reducing the amount of programming required to obtain it. Moreover, we have developed a client satellite tracking software that uses our virtual ground station. In this paper, we review the design and implementation of our virtual ground station concept. We also present the companion client satellite tracking software that we have developed

    Making Sense out of Antisense Transcription in Human T-Cell Lymphotropic Viruses (HTLVs)

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    Retroviral gene expression generally depends on a full-length transcript that initiates in the 5′ long terminal repeat (LTR), which is either unspliced or alternatively spliced. We and others have demonstrated the existence of an antisense transcript initiating in the 3′ LTR of the Human T-cell Leukemia Virus type 1 (HTLV-1) that is involved in the production of HBZ (HTLV-1 basic leucine zipper (bZIP) factor). HBZ is a Fos-like factor capable of inhibiting Tax-mediated activation of the HTLV-1 LTR by interacting with the cellular transcription factor cAMP-response element-binding protein (CREB) and the pleiotropic cellular coactivators p300/CBP. HBZ can also activate cellular transcription through its interaction with p300/CBP. Interestingly, HBZ has also been found to promote T-lymphocyte proliferation. By down-regulating viral expression and by stimulating T-cell proliferation, HBZ could be essential in the establishment of a chronic infection. Antisense transcription also occurs in the closely related HTLV-2 retrovirus as well as in the recently discovered HTLV-3 and HTLV-4. These antisense transcripts are also involved in the production of retroviral proteins that we have termed Antisense Protein of HTLVs (APH). Like HBZ, the APH proteins are localized in the nucleus of transfected cells and repress Tax-mediated viral transcription
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