252,555 research outputs found

    Immunological memory≠protective immunity

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    So-called ‘immunological memory' is, in my view, a typical example where a field of enquiry, i.e. to understand long-term protection to survive reexposure to infection, has been overtaken by ‘l'art pour l'art' of ‘basic immunology'. The aim of this critical review is to point out some key differences between academic text book-defined immunological memory and protective immunity as viewed from a co-evolutionary point of view, both from the host and the infectious agents. A key conclusion is that ‘immunological memory' of course exists, but only in particular experimental laboratory models measuring ‘quicker and better' responses after an earlier immunization. These often do correlate with, but are not the key mechanisms of, protection. Protection depends on pre-existing neutralizing antibodies or pre-activated T cells at the time of infection—as documented by the importance of maternal antibodies around birth for survival of the offspring. Importantly, both high levels of antibodies and of activated T cells are antigen driven. This conclusion has serious implications for our thinking about vaccines and maintaining a level of protection in the population to deal with old and new infectious disease

    Impact of “Golden” tomato juice on cognitive alterations in metabolic syndrome: Insights into behavioural and biochemical changes in a high-fat diet rat model

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    “Golden” tomato (GT) plays a protective role in metabolic dysfunction induced by High-Fat Diet (HFD). Our aim is to characterize the phytonutrient composition of the juice and explore the influence of GT, orally administered for one month, on cognitive impairment associated with Metabolic Syndrome (MetS) in male rats. We investigated reactivity, stress response and memory, together with brain neurotrophic/inflammatory signaling. Our data showed that HFD-induced functional modifications were ameliorated by GT nutritional supplementation. In particular, the behavioural reactivity improved in HFD/GT rats, that also showed a better performance in tests measuring anxiety and anhedonia. Furthermore, GT consumption rescued the declarative memory impairment. Lastly, GT supplementation counteracted HFD-induced brain alterations in PI3K\Akt and MAPK/ERK signalling pathways. In conclusion, this study provides evidence of the importance of food supplementation with GT in the protection from neuroinflammation and cognitive alterations associated with MetS

    Analyzing the Gadgets Towards a Metric to Measure Gadget Quality

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    Current low-level exploits often rely on code-reuse, whereby short sections of code (gadgets) are chained together into a coherent exploit that can be executed without the need to inject any code. Several protection mechanisms attempt to eliminate this attack vector by applying code transformations to reduce the number of available gadgets. Nevertheless, it has emerged that the residual gadgets can still be sufficient to conduct a successful attack. Crucially, the lack of a common metric for "gadget quality" hinders the effective comparison of current mitigations. This work proposes four metrics that assign scores to a set of gadgets, measuring quality, usefulness, and practicality. We apply these metrics to binaries produced when compiling programs for architectures implementing Intel's recent MPX CPU extensions. Our results demonstrate a 17% increase in useful gadgets in MPX binaries, and a decrease in side-effects and preconditions, making them better suited for ROP attacks.Comment: International Symposium on Engineering Secure Software and Systems, Apr 2016, London, United Kingdo

    Index to NASA Tech Briefs, 1975

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    This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

    Handheld-Impedance-Measurement System with seven-decade capability and potentiostatic function

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    This paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 kΩ to 100 GΩ. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligibl

    CYCLOSA: Decentralizing Private Web Search Through SGX-Based Browser Extensions

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    By regularly querying Web search engines, users (unconsciously) disclose large amounts of their personal data as part of their search queries, among which some might reveal sensitive information (e.g. health issues, sexual, political or religious preferences). Several solutions exist to allow users querying search engines while improving privacy protection. However, these solutions suffer from a number of limitations: some are subject to user re-identification attacks, while others lack scalability or are unable to provide accurate results. This paper presents CYCLOSA, a secure, scalable and accurate private Web search solution. CYCLOSA improves security by relying on trusted execution environments (TEEs) as provided by Intel SGX. Further, CYCLOSA proposes a novel adaptive privacy protection solution that reduces the risk of user re- identification. CYCLOSA sends fake queries to the search engine and dynamically adapts their count according to the sensitivity of the user query. In addition, CYCLOSA meets scalability as it is fully decentralized, spreading the load for distributing fake queries among other nodes. Finally, CYCLOSA achieves accuracy of Web search as it handles the real query and the fake queries separately, in contrast to other existing solutions that mix fake and real query results

    A microprocessor based, multi-channel low-temperature monitoring system

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    A multi-channel low-temperature monitoring system and its design considerations are presented. The system is microprocessor based and specially designed to interface thermoresistive sensors in cryogenic experiments. The system can be easily expanded to accept any type of physical transducer and to perform other output functions, ie control functions

    Loss-tolerant operations in parity-code linear optics quantum computing

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    A heavy focus for optical quantum computing is the introduction of error-correction, and the minimisation of resource requirements. We detail a complete encoding and manipulation scheme designed for linear optics quantum computing, incorporating scalable operations and loss-tolerant architecture.Comment: 8 pages, 6 figure

    Managing intellectual capital : individual rights and the public interest

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    Managing intellectual capital and intellectual property is a challenging task, especially for knowledge-based organisations vested with a public interest. Scientific ethics and freedom of information may clash with copyright law or with other intellectual property enactments, thereby engendering conflicts of interest. International law and treaties make for a complex regulatory framework. World-wide advocacy of the open access principle has led to some statutory changes, but its proponents mostly assume that copyright owners will act voluntarily. The implications for knowledge management are elucidated
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