139 research outputs found

    A Micro-Payment Scheme Encouraging Collaboration in Multi-Hop Cellular Networks

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    We propose a micro-payment scheme for multi-hop cellular networks that encourages collaboration in packet forwarding by letting users benefit from relaying others` packets. At the same time as proposing mechanisms for detecting and rewarding collaboration, we introduce appropriate mechanisms for detecting and punishing various forms of abuse. We show that the resulting scheme -- which is exceptionally light-weight -- makes collaboration rational and cheating undesirable

    Secure Vehicular Communication Systems: Implementation, Performance, and Research Challenges

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    Vehicular Communication (VC) systems are on the verge of practical deployment. Nonetheless, their security and privacy protection is one of the problems that have been addressed only recently. In order to show the feasibility of secure VC, certain implementations are required. In [1] we discuss the design of a VC security system that has emerged as a result of the European SeVeCom project. In this second paper, we discuss various issues related to the implementation and deployment aspects of secure VC systems. Moreover, we provide an outlook on open security research issues that will arise as VC systems develop from today's simple prototypes to full-fledged systems

    Complementary and Alternative Medicine for Chronic Prostatitis/Chronic Pelvic Pain Syndrome

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    To discuss challenges concerning treatment for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and review complementary and alternative medical (CAM) therapies being evaluated for this condition, we performed a comprehensive search of articles published from 1990–2005 using the PubMed, Medline databases. Data from the articles were abstracted and pooled by subject. Keywords cross-searched with CP/CPPS included: complementary, alternative, integrative, therapies, interventions, nutrition, antioxidants, herbs, supplements, biofeedback and acupuncture. Listed articles with no abstracts were not included. Various CAM therapies for CP/CPPS exist including biofeedback, acupuncture, hyperthermia and electrostimulation. Additionally, a variety of in vitro and in vivo studies testing herbal and nutritional supplements were found. Saw palmetto, cernilton and quercetin were the most frequently tested supplements for CP/CPPS. Although many CAM therapies demonstrate positive preliminary observations as prospective treatments for CP/CPPS, further exploratory studies including more randomized, controlled trials are necessary for significant validation as treatment options for this complex disorder

    Fault Detection in Autonomic Networks Using the Concept of Promised Cooperation

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    Collaborative Location Privacy with Rational Users

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    Recent smartphones incorporate embedded GPS devices that enable users to obtain geographic information about their surroundings by providing a location-based service (LBS) with their current coordinates. However, LBS providers collect a significant amount of data from mobile users and could be tempted to misuse it, by compromising a customer's location privacy (her ability to control the information about her past and present location). Many solutions to mitigate this privacy threat focus on changing both the architecture of location-based systems and the business models of LBS providers. MobiCrowd does not introduce changes to the existing business practices of LBS providers, rather it requires mobile devices to communicate wirelessly in a peer-to-peer fashion. To lessen the privacy loss, users seeking geographic information try to obtain this data by querying neighboring nodes, instead of connecting to the LBS. However, such a solution will only function if users are willing to share regional data obtained from the LBS provider. We model this collaborative location-data sharing problem with rational agents following threshold strategies. Initially, we study agent cooperation by using pure game theory and then by combining game theory with an epidemic model that is enhanced to support threshold strategies to address a complex multi-agent scenario. From our game-theoretic analysis, we derive cooperative and non-cooperative Nash equilibria and the optimal threshold that maximizes agents' expected utility

    Computing Nash Equilibrium in Wireless Ad Hoc Networks: A Simulation-Based Approach

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    This paper studies the problem of computing Nash equilibrium in wireless networks modeled by Weighted Timed Automata. Such formalism comes together with a logic that can be used to describe complex features such as timed energy constraints. Our contribution is a method for solving this problem using Statistical Model Checking. The method has been implemented in UPPAAL model checker and has been applied to the analysis of Aloha CSMA/CD and IEEE 802.15.4 CSMA/CA protocols.Comment: In Proceedings IWIGP 2012, arXiv:1202.422

    Delineation of prognostic biomarkers in prostate cancer

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    Prostate cancer is the most frequently diagnosed cancer in American men(1,2). Screening for prostate-specific antigen (PSA) has led to earlier detection of prostate cancer(3), but elevated serum PSA levels may be present in non-malignant conditions such as benign prostatic hyperlasia (BPH). Characterization of gene-expression profiles that molecularly distinguish prostatic neoplasms may identify genes involved in prostate carcinogenesis, elucidate clinical biomarkers, and lead to an improved classification of prostate cancer(4-6). Using microarrays of complementary DNA, we examined gene-expression profiles of more than 50 normal and neoplastic prostate specimens and three common prostate-cancer cell lines. Signature expression profiles of normal adjacent prostate (NAP), BPH, localized prostate cancer, and metastatic, hormone-refractory prostate cancer were determined. Here we establish many associations between genes and prostate cancer. We assessed two of these genes-hepsin, a transmembrane serine protease, and pim-1, a serine/threonine kinase-at the protein level using tissue microarrays consisting of over 700 clinically stratified prostate-cancer specimens. Expression of hepsin and pim-1 proteins was significantly correlated with measures of clinical outcome. Thus, the integration of cDNA microarray, high-density tissue microarray, and linked clinical and pathology data is a powerful approach to molecular profiling of human cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62849/1/412822a0.pd

    Alzheimer's risk variants in the clusterin gene are associated with alternative splicing

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    Genetic variation in CLU encoding clusterin has been associated with Alzheimer's disease (AD) through replicated genome-wide studies, but the underlying mechanisms remain unknown. Following earlier reports that tightly regulated CLU alternative transcripts have different functions, we tested CLU single-nucleotide polymorphisms (SNPs), including those associated with AD for quantitative effects on individual alternative transcripts. In 190 temporal lobe samples without pathology, we found that the risk allele of the AD-associated SNP rs9331888 increases the relative abundance of transcript NM_203339 (P=4.3 × 10−12). Using an independent set of 115 AD and control samples, we replicated this result (P=0.0014) and further observed that multiple CLU transcripts are at higher levels in AD compared with controls. The AD SNP rs9331888 is located in the first exon of NM_203339 and therefore, it is a functional candidate for the observed effects. We tested this hypothesis by in vitro dual luciferase assays using SK-N-SH cells and mouse primary cortical neurons and found allelic effects on enhancer function, consistent with our results on post-mortem human brain. These results suggest a biological mechanism for the genetic association of CLU with AD risk and indicate that rs9331888 is one of the functional DNA variants underlying this association
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