2,411 research outputs found

    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

    INTERIM REPORT IMPROVED METHODS FOR INCORPORATING RISK IN DECISION MAKING

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    This paper reports observations and preliminary investigations in the first phase of a research program covering methodologies for making safety-related decisions. The objective has been to gain insight into NRC perceptions of the value of formal decision methods, their possible applications, and how risk is, or may be, incorporated in decision making. The perception of formal decision making techniques, held by various decision makers, and what may be done to improve them, were explored through interviews with NRC staff. An initial survey of decision making methods, an assessment of the applicability of formal methods vis-a-vis the available information, and a review of methods of incorporating risk and uncertainty have also been conducted

    Prochlo: Strong Privacy for Analytics in the Crowd

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    The large-scale monitoring of computer users' software activities has become commonplace, e.g., for application telemetry, error reporting, or demographic profiling. This paper describes a principled systems architecture---Encode, Shuffle, Analyze (ESA)---for performing such monitoring with high utility while also protecting user privacy. The ESA design, and its Prochlo implementation, are informed by our practical experiences with an existing, large deployment of privacy-preserving software monitoring. (cont.; see the paper

    Security analysis of standard authentication and key agreement protocols utilising timestamps

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    We propose a generic modelling technique that can be used to extend existing frameworks for theoretical security analysis in order to capture the use of timestamps. We apply this technique to two of the most popular models adopted in literature (Bellare-Rogaway and Canetti-Krawczyk). We analyse previous results obtained using these models in light of the proposed extensions, and demonstrate their application to a new class of protocols. In the timed CK model we concentrate on modular design and analysis of protocols, and propose a more efficient timed authenticator relying on timestamps. The structure of this new authenticator implies that an authentication mechanism standardised in ISO-9798 is secure. Finally, we use our timed extension to the BR model to establish the security of an efficient ISO protocol for key transport and unilateral entity authentication

    Serious fungal infections in Portugal

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    There is a lack of knowledge on the epidemiology of fungal infections worldwide because there are no reporting obligations. The aim of this study was to estimate the burden of fungal disease in Portugal as part of a global fungal burden project. Most published epidemiology papers reporting fungal infection rates from Portugal were identified. Where no data existed, specific populations at risk and fungal infection frequencies in those populations were used in order to estimate national incidence or prevalence, depending on the condition. An estimated 1,510,391 persons develop a skin or nail fungal infection each year. The second most common fungal infection in Portugal is recurrent vulvovaginal candidiasis, with an estimated 150,700 women (15-50 years of age) suffering from it every year. In human immunodeficiency virus (HIV)-infected people, oral or oesophageal candidiasis rates were estimated to be 19.5 and 16.8/100,000, respectively. Candidaemia affects 2.19/100,000 patients, in a total of 231 cases nationally. Invasive aspergillosis is less common than in other countries as chronic obstructive pulmonary disease (COPD) is uncommon in Portugal, a total of 240 cases annually. The estimated prevalence of chronic pulmonary aspergillosis after tuberculosis (TB) is 194 cases, whereas its prevalence for all underlying pulmonary conditions was 776 patients. Asthma is common (10% in adults) and we estimate 16,614 and 12,600 people with severe asthma with fungal sensitisation and allergic bronchopulmonary aspergillosis, respectively. Sixty-five patients develop Pneumocystis pneumonia in acquired immune deficiency syndrome (AIDS) and 13 develop cryptococcosis. Overall, we estimate a total number of 1,695,514 fungal infections starting each year in Portugal.info:eu-repo/semantics/publishedVersio

    5-hydroxymethyl-cytosine enrichment of non-committed cells is not a universal feature of vertebrate development

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    5-hydroxymethyl-cytosine (5-hmC) is a cytosine modification that is relatively abundant in mammalian pre-implantation embryos and embryonic stem cells (ESC) derived from mammalian blastocysts. Recent observations imply that both 5-hmC and Tet1/2/3 proteins, catalyzing the conversion of 5-methyl-cytosine to 5-hmC, may play an important role in self renewal and differentiation of ESCs. Here we assessed the distribution of 5-hmC in zebrafish and chick embryos and found that, unlike in mammals, 5-hmC is immunochemically undetectable in these systems before the onset of organogenesis. In addition, Tet1/2/3 transcripts are either low or undetectable at corresponding stages of zebrafish development. However, 5-hmC is enriched in later zebrafish and chick embryos and exhibits tissue-specific distribution in adult zebrafish. Our findings show that 5-hmC enrichment of non-committed cells is not a universal feature of vertebrate development and give insights both into evolution of embryonic pluripotency and the potential role of 5-hmC in its regulation. © 2012 Landes Bioscience

    Primary Invasive Aspergillosis of the Digestive Tract: Report of Two Cases and Review of the Literature

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    BACKGROUND: Disseminated aspergillosis is thought to occur as a result of vascular invasion from the lungs with subsequent bloodstream dissemination, and portals of entry other than sinuses and/or the respiratory tract remain speculative. METHODS: We report two cases of primary aspergillosis in the digestive tract and present a detailed review of eight of the 23 previously-published cases for which detailed data are available. RESULTS AND CONCLUSION: These ten cases presented with symptoms suggestive of typhlitis, with further peritonitis requiring laparotomy and small bowel segmental resection. All cases were characterized by the absence of pulmonary disease at the time of histologically-confirmed gastrointestinal involvement with vascular invasion by branched Aspergillus hyphae. These cases suggest that the digestive tract may represent a portal of entry for Aspergillus species in immunocompromised patients
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