188 research outputs found

    Imaging in extrapulmonary tuberculosis

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    Tuberculosis (TB) remains a major global public health problem, with 1.5 million deaths annually worldwide. One in five cases of TB present as extrapulmonary TB (EPTB), posing major diagnostic and management challenges. Mycobacterium tuberculosis adapts to a quiescent physiological state and is notable for its complex interaction with the host, producing poorly understood disease states ranging from latent infection to active clinical disease. New tools in the diagnostic armamentarium are urgently required for the rapid diagnosis of TB and monitoring of TB treatments, and to gain new insights into pathogenesis. The typical and atypical imaging features of EPTB are reviewed herein, and the roles of several imaging modalities for the diagnosis and management of EPTB are discussed

    Language attitudes and use in a transplanted setting: Greek Cypriots in London

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    In this paper we explore language attitudes and use in the Greek Cypriot community in London, England. Our study is based on an earlier survey carried out in Nicosia, Cyprus and we compare attitudes to language and reported language use in the two communities. We thereby highlight the significance of sociolinguistic variables on similar groups of speakers. We further extend our investigation to include codeswitching practices in the London community. \ud Analysis of language attitudes and use within the Greek-Cypriot population of London, and comparisons with findings in Nicosia, reflect symbolic forces operating in the two contexts. Despite obvious differences between the two communities, (most obviously the official languages and distinct cultural backgrounds of the two nations), the Greek Cypriot Dialect continues to play an active role in both. English is however the ‘default choice‘ for young Cypriots in the UK and Standard Modern Greek occupies a much more limited role than in Cyprus. It is argued that differences in language attitudes and use can be interpreted in light of different market forces operating in the nation (i.e. Cyprus) and the Diaspora (i.e. UK)

    Robust implications on Dark Matter from the first FERMI sky gamma map

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    We derive robust model-independent bounds on DM annihilations and decays from the first year of FERMI gamma-ray observations of the whole sky. These bounds only have a mild dependence on the DM density profile and allow the following DM interpretations of the PAMELA and FERMI electron/positron excesses: primary channels mu+ mu-, mu+ mu-mu+mu- or e+ e- e+ e-. An isothermal-like density profile is needed for annihilating DM. In all such cases, FERMI gamma spectra must contain a significant DM component, that may be probed in the future.Comment: 16 pages, 8 figures. Final versio

    A Public Option for the Core

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    This paper is focused not on the Internet architecture – as deïŹned by layering, the narrow waist of IP, and other core design principles – but on the Internet infrastructure, as embodied in the technologies and organizations that provide Internet service. In this paper we discuss both the challenges and the opportunities that make this an auspicious time to revisit how we might best structure the Internet’s infrastructure. Currently, the tasks of transit-between-domains and last-mile-delivery are jointly handled by a set of ISPs who interconnect through BGP. In this paper we propose cleanly separating these two tasks. For transit, we propose the creation of a “public option” for the Internet’s core backbone. This public option core, which complements rather than replaces the backbones used by large-scale ISPs, would (i) run an open market for backbone bandwidth so it could leverage links oïŹ€ered by third-parties, and (ii) structure its terms-of-service to enforce network neutrality so as to encourage competition and reduce the advantage of large incumbents

    Dynamical Stability of Six-Dimensional Warped Brane-Worlds

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    We study a generalization of the Randall-Sundrum mechanism for generating the weak/Planck hierarchy, which uses two rather than one warped extra dimension, and which requires no negative tension branes. A 4-brane with one exponentially large compact dimension plays the role of the Planck brane. We investigate the dynamical stability with respect to graviton, graviphoton and radion modes. The radion is shown to have a tachyonic instability for certain models of the 4-brane stress-energy, while it is stable in others, and massless in a special case. If stable, its mass is in the milli-eV range, for parameters of the model which solve the hierarchy problem. The radion is shown to couple to matter with gravitational strength, so that it is potentially detectable by submillimeter-range gravity experiments. The radion mass can be increased using a bulk scalar field in the manner of Goldberger and Wise, but only to order MeV, due to the effect of the large extra dimension. The model predicts a natural scale of 10^{13} GeV on the 4-brane, making it a natural setting for inflation from the ultraviolet brane.Comment: 28 pages, 7 figure

    PET/CT features of extrapulmonary tuberculosis at first clinical presentation: a cross-sectional observational Âč⁞F-FDG imaging study across six countries

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    BACKGROUND: A large proportion of the huge global burden of Extrapulmonary tuberculosis (EPTB) are treated empirically without accurate definition of disease sites, and extent of multi-organ disease involvement. Positron emission tomography (PET) imaging using 18F-FDG in TB could be a useful imaging technique for localising disease sites and extent of disease. METHODS: We conducted a study of HIV-negative adult patients with a new clinical diagnosis of EPTB across 8 centres located in 6 countries: India, Pakistan, Thailand, South Africa, Serbia, and Bangladesh to assess the extent of disease and common sites involved at first presentation. 18F-FDG PET/CT scans were performed within 2 weeks of presentation. FINDINGS: A total of 358 patients with EPTB (189 females; 169 males) were recruited over 45 months. Age range 18-83 years (females: median 30 years; males: median 38 years). 350/358 (98%) patients (183 female, 167 male) had positive scan. 118/350 (33.7%) had a single extrapulmonary site and 232/350 (66.3%) had more than one site (organ) affected. Lymph nodes, skeletal, pleura and brain were common sites. 100/358 (28%) of EPTB patients had 18F-FDG PET/CT positive sites in the lung. 110 patients were 18F-FDG PET/CT positive in more body sites than were noted clinically at first presentation and 160 patients had the same number of positive body sites. INTERPRETATION: 18F-FDG PET/CT scan has potential for further elucidating the spectrum of disease, pathogenesis of EPTB, and monitoring the effects of treatment on active lesions over time, and requires longitudinal cohort studies, twinned with biopsy and molecular studies

    Multimodal assessment of painful peripheral neuropathy induced by chronic oxaliplatin-based chemotherapy in mice

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    <p>Abstract</p> <p>Background</p> <p>A major clinical issue affecting 10-40% of cancer patients treated with oxaliplatin is severe peripheral neuropathy with symptoms including cold sensitivity and neuropathic pain. Rat models have been used to describe the pathological features of oxaliplatin-induced peripheral neuropathy; however, they are inadequate for parallel studies of oxaliplatin's antineoplastic activity and neurotoxicity because most cancer models are developed in mice. Thus, we characterized the effects of chronic, bi-weekly administration of oxaliplatin in BALB/c mice. We first studied oxaliplatin's effects on the peripheral nervous system by measuring caudal and digital nerve conduction velocities (NCV) followed by ultrastructural and morphometric analyses of dorsal root ganglia (DRG) and sciatic nerves. To further characterize the model, we examined nocifensive behavior and central nervous system excitability by <it>in vivo </it>electrophysiological recording of spinal dorsal horn (SDH) wide dynamic range neurons in oxaliplatin-treated mice</p> <p>Results</p> <p>We found significantly decreased NCV and action potential amplitude after oxaliplatin treatment along with neuronal atrophy and multinucleolated DRG neurons that have eccentric nucleoli. Oxaliplatin also induced significant mechanical allodynia and cold hyperalgesia, starting from the first week of treatment, and a significant increase in the activity of wide dynamic range neurons in the SDH.</p> <p>Conclusions</p> <p>Our findings demonstrate that chronic treatment with oxaliplatin produces neurotoxic changes in BALB/c mice, confirming that this model is a suitable tool to conduct further mechanistic studies of oxaliplatin-related antineoplastic activity, peripheral neurotoxicity and pain. Further, this model can be used for the preclinical discovery of new neuroprotective and analgesic compounds.</p
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