2,561 research outputs found

    On the Derivation of Lattice Structured Information Flow Policies

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    The Profession of IT Learning Machine Learning

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    The article of record as published may be found at http://dx.doi.org/10.1145/3286868A discussion of the rapidly evolving realm of machine learning

    Gastrointestinal Stromal Tumors (GIST)

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    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, occurring predominantly in the stomach and small intestine. These tumors account for up to 3% of all gastrointestinal malignancies, with a reported annual incidence of 10–15 cases per million population. GISTs are thought to originate from interstitial cells of Cajal (ICC) or ICC precursor cells, and are characterized by activating mutations in the KIT (CD117) and platelet-derived growth factor receptor alpha (PDGFRα) proto-oncogenes in 85–95% of all cases. The clinical presentation and tumor biology of GISTs are widely variable, with several advances being made over the past two decades in the understanding of GIST tumor biology and pathophysiology. This has led to a paradigm shift in management from the purely surgical approach of the past, to a multi-modality treatment strategy with a greater role for targeted therapies in the form of tyrosine kinase inhibitors, resulting in significantly improved patient outcomes

    White paper: A plan for cooperation between NASA and DARPA to establish a center for advanced architectures

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    Large, complex computer systems require many years of development. It is recognized that large scale systems are unlikely to be delivered in useful condition unless users are intimately involved throughout the design process. A mechanism is described that will involve users in the design of advanced computing systems and will accelerate the insertion of new systems into scientific research. This mechanism is embodied in a facility called the Center for Advanced Architectures (CAA). CAA would be a division of RIACS (Research Institute for Advanced Computer Science) and would receive its technical direction from a Scientific Advisory Board established by RIACS. The CAA described here is a possible implementation of a center envisaged in a proposed cooperation between NASA and DARPA

    New and Little Known Species of Nearctic Trichoptera

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    Aspergillus nodules; another presentation of Chronic Pulmonary Aspergillosis

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    BACKGROUND: There are a number of different manifestations of pulmonary aspergillosis. This study aims to review the radiology, presentation, and histological features of lung nodules caused by Aspergillus spp. METHODS: Patients were identified from a cohort attending our specialist Chronic Pulmonary Aspergillosis clinic. Patients with cavitating lung lesions, with or without fibrosis and those with aspergillomas or a diagnosis of invasive aspergillosis were excluded. Demographic, laboratory, and clinical data and radiologic findings were recorded. RESULTS: Thirty-three patients with pulmonary nodules and diagnostic features of aspergillosis (histology and/or laboratory findings) were identified. Eighteen (54.5 %) were male, mean age 58 years (range 27–80 years). 19 (57.6 %) were former or current smokers. The median Charleston co-morbidity index was 3 (range 0–7). All complained of a least one of; dyspnoea, cough, haemoptysis, or weight loss. None reported fever. Ten patients (31 %) did not have an elevated Aspergillus IgG, and only 4 patients had elevated Aspergillus precipitins. Twelve patients (36 %) had a single nodule, six patients (18 %) had between 2 and 5 nodules, 2 (6 %) between 6 and 10 nodules and 13 (39 %) had more than 10 nodules. The mean size of the nodules was 21 mm, with a maximum size ranging between 5–50 mm. No nodules had cavitation radiographically. The upper lobes were most commonly involved. Histology was available for 18 patients and showed evidence of granulation tissue, fibrosis, and visualisation of fungal hyphae. CONCLUSION: Pulmonary nodules are a less common manifestation of aspergillosis in immunocompetent patients. Distinguishing these nodules from other lung pathology may be difficult on CT findings alone

    Refactoring preserves security

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    Refactoring allows changing a program without changing its behaviour from an observer’s point of view. To what extent does this invariant of behaviour also preserve security? We show that a program remains secure under refactoring. As a foundation, we use the Decentralized Label Model (DLM) for specifying secure information flows of programs and transition system models for their observable behaviour. On this basis, we provide a bisimulation based formal definition of refactoring and show its correspondence to the formal notion of information flow security (noninterference). This permits us to show security of refactoring patterns that have already been practically explored

    Aspergillus fumigatus allergen expression is coordinately regulated in response to hydrogen peroxide and cyclic AMP

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    <p>Abstract</p> <p>Background</p> <p><it>A. fumigatus </it>has been associated with a wide spectrum of allergic disorders such as ABPA or SAFS. It is poorly understood what allergens in particular are being expressed during fungal invasion and which are responsible for stimulation of immune responses. Study of the dynamics of allergen production by fungi may lead to insights into how allergens are presented to the immune system.</p> <p>Methods</p> <p>Expression of 17 <it>A. fumigatus </it>allergen genes was examined in response to various culture conditions and stimuli as well as in the presence of macrophages in order to mimic conditions encountered in the lung.</p> <p>Results</p> <p>Expression of 14/17 allergen genes was strongly induced by oxidative stress caused by hydrogen peroxide (Asp f 1, -2, -4, -5, -6, -7, -8, -10, -13, -17 and -18, all >10-fold and Asp f 11, -12, and -22, 5-10-fold) and 16/17 allergen genes were repressed in the presence of cAMP. The 4 protease allergen genes (Asp f -5, -10, -13 and -18) were expressed at very low levels compared to the comparator (<it>β</it>-tubulin) under all other conditions examined. Mild heat shock, anoxia, lipid and presence of macrophages did not result in coordinated changes in allergen gene expression. Growth on lipid as sole carbon source contributed to the moderate induction of most of the allergen genes. Heat shock (37°C > 42°C) caused moderate repression in 11/17 genes (Asp f 1, -2, -4, -5, -6, -9, -10, -13, -17, -18 and -23) (2- to 9-fold), which was mostly evident for Asp f 1 and -9 (~9-fold). Anaerobic stress led to moderate induction of 13/17 genes (1.1 to 4-fold) with one, Asp f 8 induced over 10-fold when grown under mineral oil. Complex changes were seen in gene expression during co-culture of <it>A. fumigatus </it>with macrophages.</p> <p>Conclusions</p> <p>Remarkable coordination of allergen gene expression in response to a specific condition (oxidative stress or the presence of cAMP) has been observed, implying that a single biological stimulus may play a role in allergen gene regulation. Interdiction of a putative allergen expression induction signalling pathway might provide a novel therapy for treatment of fungal allergy.</p

    Cellular automaton rules conserving the number of active sites

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    This paper shows how to determine all the unidimensional two-state cellular automaton rules of a given number of inputs which conserve the number of active sites. These rules have to satisfy a necessary and sufficient condition. If the active sites are viewed as cells occupied by identical particles, these cellular automaton rules represent evolution operators of systems of identical interacting particles whose total number is conserved. Some of these rules, which allow motion in both directions, mimic ensembles of one-dimensional pseudo-random walkers. Numerical evidence indicates that the corresponding stochastic processes might be non-Gaussian.Comment: 14 pages, 5 figure
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