937 resultados para Distributed non-coherent shared memory
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The self-reference effect (SRE) in memory is thought to depend on specialized mechanisms that enhance memory for self-relevant information. We investigated whether these mechanisms can be engaged “by proxy” when we simulate other people, by asking participants to interact with two virtual partners: one similar and one dissimilar to self. Participants viewed pairs of objects and picked one for themselves, for their similar partner, or their dissimilar partner. A surprise memory test followed that required participants to identify which object of each pair was chosen, and for whom. Finally, participants were shown both partners’ object pairs again, and asked to indicate their personal preference. Four key findings were observed. Overlap between participants’ own choice and those made for their partner was significantly higher for the similar than the dissimilar partner, revealing participants’ use of their own preferences to simulate the similar partner. Recollection of chosen objects was significantly higher for self than for both partners and, critically, was significantly higher for similar than dissimilar partners. Source confusion between self and the similar partner was also higher. These findings suggest that self-reference by proxy enhances memory for non-self-relevant material, and we consider the theoretical implications for functional interpretation of the SRE.
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Background: The Nme gene family is involved in multiple physiological and pathological processes such as cellular differentiation, development, metastatic dissemination, and cilia functions. Despite the known importance of Nme genes and their use as clinical markers of tumor aggressiveness, the associated cellular mechanisms remain poorly understood. Over the last 20 years, several non-vertebrate model species have been used to investigate Nme functions. However, the evolutionary history of the family remains poorly understood outside the vertebrate lineage. The aim of the study was thus to elucidate the evolutionary history of the Nme gene family in Metazoans. Methodology/Principal Findings: Using a total of 21 eukaryote species including 14 metazoans, the evolutionary history of Nme genes was reconstructed in the metazoan lineage. We demonstrated that the complexity of the Nme gene family, initially thought to be restricted to chordates, was also shared by the metazoan ancestor. We also provide evidence suggesting that the complexity of the family is mainly a eukaryotic innovation, with the exception of Nme8 that is likely to be a choanoflagellate/metazoan innovation. Highly conserved gene structure, genomic linkage, and protein domains were identified among metazoans, some features being also conserved in eukaryotes. When considering the entire Nme family, the starlet sea anemone is the studied metazoan species exhibiting the most conserved gene and protein sequence features with humans. In addition, we were able to show that most of the proteins known to interact with human NME proteins were also found in starlet sea anemone. Conclusion/Significance: Together, our observations further support the association of Nme genes with key cellular functions that have been conserved throughout metazoan evolution. Future investigations of evolutionarily conserved Nme gene functions using the starlet sea anemone could shed new light on a wide variety of key developmental and cellular processes.
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The Open Journal project has completed its three year period of funding by the UK Electronic Libraries (eLib) programme (Rusbridge 1998). During that time, the number of journals that are available electronically leapt from a few tens to a few thousand. Some of these journals are now developing the sort of features the project has been advocating, in particular the use of links within journals, between different primary journals, with secondary journals data, and to non-journal sources. Assessing the achievements of the project and considering some of the difficulties it faced, we report on the different approaches to linking that the project developed, and summarise the important user responses that indicate what works and what does not. Looking ahead, there are signs of change, not just to simple linking within journals but to schemes in which links are the basis of "distributed" journals, where information may be shared and documents built from different sources. The significance has yet to be appreciated, but this would be a major change from printed journals. If projects such as this and others have provided the initial impetus, the motivation for distributed journals comes, perhaps surprisingly, from within certain parts of the industry, as the paper shows.
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Securing e-health applications in the context of Internet of Things (IoT) is challenging. Indeed, resources scarcity in such environment hinders the implementation of existing standard based protocols. Among these protocols, MIKEY (Multimedia Internet KEYing) aims at establishing security credentials between two communicating entities. However, the existing MIKEY modes fail to meet IoT specificities. In particular, the pre-shared key mode is energy efficient, but suffers from severe scalability issues. On the other hand, asymmetric modes such as the public key mode are scalable, but are highly resource consuming. To address this issue, we combine two previously proposed approaches to introduce a new hybrid MIKEY mode. Indeed, relying on a cooperative approach, a set of third parties is used to discharge the constrained nodes from heavy computational operations. Doing so, the pre-shared mode is used in the constrained part of the network, while the public key mode is used in the unconstrained part of the network. Preliminary results show that our proposed mode is energy preserving whereas its security properties are kept safe.
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Cat’s claw creeper vine, Dolichandra unguis-cati (L.) Lohmann (syn. Macfadyena unguis-cati (L.) Gentry) (Bignoniaceae), is a major environmental weed in Australia. Two distinct forms of this weed (‘long’ and ‘short’ pod), with differences in leaf morphology and fruit size, occur in Australia. The long pod form has only been reported in less than fifteen localities in the whole of south-east Queensland, while the short pod form is widely distributed in Queensland and New South Wales. This study sought to compare growth traits such as specific leaf area, relative growth rate, stem length, shoot/root ratio, tuber biomass and branching architecture between these forms. These traits were monitored under glasshouse conditions over a period of 18 months. Short pod exhibited higher values of relative growth rates, stem length, number of tubers and specific leaf area than long pod, but only after 10 months of plant growth. Prior to this, long and short pod did not differ significantly. Higher values for these traits have been described as characteristics of successful colonizers. Results from this study could partly explain why the short pod form is more widely distributed in Australia while long pod is confined to a few localities.
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Studies of non-equilibrium current fluctuations enable assessing correlations involved in quantum transport through nanoscale conductors. They provide additional information to the mean current on charge statistics and the presence of coherence, dissipation, disorder, or entanglement. Shot noise, being a temporal integral of the current autocorrelation function, reveals dynamical information. In particular, it detects presence of non-Markovian dynamics, i.e., memory, within open systems, which has been subject of many current theoretical studies. We report on low-temperature shot noise measurements of electronic transport through InAs quantum dots in the Fermi-edge singularity regime and show that it exhibits strong memory effects caused by quantum correlations between the dot and fermionic reservoirs. Our work, apart from addressing noise in archetypical strongly correlated system of prime interest, discloses generic quantum dynamical mechanism occurring at interacting resonant Fermi edges.
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The Internet has grown in size at rapid rates since BGP records began, and continues to do so. This has raised concerns about the scalability of the current BGP routing system, as the routing state at each router in a shortest-path routing protocol will grow at a supra-linearly rate as the network grows. The concerns are that the memory capacity of routers will not be able to keep up with demands, and that the growth of the Internet will become ever more cramped as more and more of the world seeks the benefits of being connected. Compact routing schemes, where the routing state grows only sub-linearly relative to the growth of the network, could solve this problem and ensure that router memory would not be a bottleneck to Internet growth. These schemes trade away shortest-path routing for scalable memory state, by allowing some paths to have a certain amount of bounded “stretch”. The most promising such scheme is Cowen Routing, which can provide scalable, compact routing state for Internet routing, while still providing shortest-path routing to nearly all other nodes, with only slightly stretched paths to a very small subset of the network. Currently, there is no fully distributed form of Cowen Routing that would be practical for the Internet. This dissertation describes a fully distributed and compact protocol for Cowen routing, using the k-core graph decomposition. Previous compact routing work showed the k-core graph decomposition is useful for Cowen Routing on the Internet, but no distributed form existed. This dissertation gives a distributed k-core algorithm optimised to be efficient on dynamic graphs, along with with proofs of its correctness. The performance and efficiency of this distributed k-core algorithm is evaluated on large, Internet AS graphs, with excellent results. This dissertation then goes on to describe a fully distributed and compact Cowen Routing protocol. This protocol being comprised of a landmark selection process for Cowen Routing using the k-core algorithm, with mechanisms to ensure compact state at all times, including at bootstrap; a local cluster routing process, with mechanisms for policy application and control of cluster sizes, ensuring again that state can remain compact at all times; and a landmark routing process is described with a prioritisation mechanism for announcements that ensures compact state at all times.
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Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.
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Technologies such as automobiles or mobile phones allow us to perform beyond our physical capabilities and travel faster or communicate over long distances. Technologies such as computers and calculators can also help us perform beyond our mental capabilities by storing and manipulating information that we would be unable to process or remember. In recent years there has been a growing interest in assistive technology for cognition (ATC) which can help people compensate for cognitive impairments. The aim of this thesis was to investigate ATC for memory to help people with memory difficulties which impacts independent functioning during everyday life. Chapter one argues that using both neuropsychological and human computing interaction theory and approaches is crucial when developing and researching ATC. Chapter two describes a systematic review and meta-analysis of studies which tested technology to aid memory for groups with ABI, stroke or degenerative disease. Good evidence was found supporting the efficacy of prompting devices which remind the user about a future intention at a set time. Chapter three looks at the prevalence of technologies and memory aids in current use by people with ABI and dementia and the factors that predicted this use. Pre-morbid use of technology, current use of non-tech aids and strategies and age (ABI group only) were the best predictors of this use. Based on the results, chapter four focuses on mobile phone based reminders for people with ABI. Focus groups were held with people with memory impairments after ABI and ABI caregivers (N=12) which discussed the barriers to uptake of mobile phone based reminding. Thematic analysis revealed six key themes that impact uptake of reminder apps; Perceived Need, Social Acceptability, Experience/Expectation, Desired Content and Functions, Cognitive Accessibility and Sensory/Motor Accessibility. The Perceived need theme described the difficulties with insight, motivation and memory which can prevent people from initially setting reminders on a smartphone. Chapter five investigates the efficacy and acceptability of unsolicited prompts (UPs) from a smartphone app (ForgetMeNot) to encourage people with ABI to set reminders. A single-case experimental design study evaluated use of the app over four weeks by three people with severe ABI living in a post-acute rehabilitation hospital. When six UPs were presented through the day from ForgetMeNot, daily reminder-setting and daily memory task completion increased compared to when using the app without the UPs. Chapter six investigates another barrier from chapter 4 – cognitive and sensory accessibility. A study is reported which shows that an app with ‘decision tree’ interface design (ApplTree) leads to more accurate reminder setting performance with no compromise of speed or independence (amount of guidance required) for people with ABI (n=14) compared to a calendar based interface. Chapter seven investigates the efficacy of a wearable reminding device (smartwatch) as a tool for delivering reminders set on a smartphone. Four community dwelling participants with memory difficulties following ABI were included in an ABA single case experimental design study. Three of the participants successfully used the smartwatch throughout the intervention weeks and these participants gave positive usability ratings. Two participants showed improved memory performance when using the smartwatch and all participants had marked decline in memory performance when the technology was removed. Chapter eight is a discussion which highlights the implications of these results for clinicians, researchers and designers.
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L’évaluation de l’action humanitaire (ÉAH) est un outil valorisé pour soutenir l’imputabilité, la transparence et l’efficience de programmes humanitaires contribuant à diminuer les inéquités et à promouvoir la santé mondiale. L’EAH est incontournable pour les parties prenantes de programme, les bailleurs de fonds, décideurs et intervenants souhaitant intégrer les données probantes aux pratiques et à la prise de décisions. Cependant, l’utilisation de l’évaluation (UÉ) reste incertaine, l’ÉAH étant fréquemment menée, mais inutilisé. Aussi, les conditions influençant l’UÉ varient selon les contextes et leur présence et applicabilité au sein d’organisations non-gouvernementales (ONG) humanitaires restent peu documentées. Les évaluateurs, parties prenantes et décideurs en contexte humanitaire souhaitant assurer l’UÉ pérenne détiennent peu de repères puisque rares sont les études examinant l’UÉ et ses conditions à long terme. La présente thèse tend à clarifier ces enjeux en documentant sur une période de deux ans l’UÉ et les conditions qui la détermine, au sein d’une stratégie d’évaluation intégrée au programme d’exemption de paiement des soins de santé d’une ONG humanitaire. L’objectif de ce programme est de faciliter l’accès à la santé aux mères, aux enfants de moins de cinq ans et aux indigents de districts sanitaires au Niger et au Burkina Faso, régions du Sahel où des crises alimentaires et économiques ont engendré des taux élevés de malnutrition, de morbidité et de mortalité. Une première évaluation du programme d’exemption au Niger a mené au développement de la stratégie d’évaluation intégrée à ce même programme au Burkina Faso. La thèse se compose de trois articles. Le premier présente une étude d’évaluabilité, étape préliminaire à la thèse et permettant de juger de sa faisabilité. Les résultats démontrent une logique cohérente et plausible de la stratégie d’évaluation, l’accessibilité de données et l’utilité d’étudier l’UÉ par l’ONG. Le second article documente l’UÉ des parties prenantes de la stratégie et comment celle-ci servit le programme d’exemption. L’utilisation des résultats fut instrumentale, conceptuelle et persuasive, alors que l’utilisation des processus ne fut qu’instrumentale et conceptuelle. Le troisième article documente les conditions qui, selon les parties prenantes, ont progressivement influencé l’UÉ. L’attitude des utilisateurs, les relations et communications interpersonnelles et l’habileté des évaluateurs à mener et à partager les connaissances adaptées aux besoins des utilisateurs furent les conditions clés liées à l’UÉ. La thèse contribue à l’avancement des connaissances sur l’UÉ en milieu humanitaire et apporte des recommandations aux parties prenantes de l’ONG.
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The self-ordered pointing test (SOPT; Petrides & Milner, 1982) is a test of non-spatial executive working memory requiring the ability to generate and monitor a sequence of responses. Although used with developmental clinical populations there are few normative data against which to compare atypical performance. Typically developing children (5!11 years) and young adults performed two versions of the SOPT, one using pictures of familiar objects and the other hard-to-verbalise abstract designs. Performance improved with age but the children did not reach adult levels of performance. Participants of all ages found the object condition easier than the abstract condition, suggesting that verbal processes are utilised by the SOPT. However, performance on the task was largely independent from verbal and nonverbal cognitive ability. Overall the results suggest that the SOPT is a sensitive measure of executive working memory.
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Archaeal replicative DNA polymerase D (PolD) constitute an atypical class of DNA polymerases made of a proofreading exonuclease subunit (DP1) and a larger polymerase catalytic subunit (DP2), both with unknown structures. We have determined the crystal structures of Pyrococcus abyssi DP1 and DP2 at 2.5 and 2.2 angstrom resolution, respectively, revealing a catalytic core strikingly different from all other known DNA polymerases (DNAPs). Rather, the PolD DP2 catalytic core has the same 'double-psi beta-barrel' architecture seen in the RNA polymerase (RNAP) superfamily, which includes multi-subunit transcriptases of all domains of life, homodimeric RNA-silencing pathway RNAPs and atypical viral RNAPs. This finding bridges together, in non-viral world, DNA transcription and DNA replication within the same protein superfamily. This study documents further the complex evolutionary history of the DNA replication apparatus in different domains of life and proposes a classification of all extant DNAPs.
Resumo:
OBJETIVO: Comparar os níveis de cortisol sérico e salivar, alfa-amilase salivar (sAA) e fluxo de saliva não estimulada (UWS) em gestantes e não gestantes. MÉTODOS: Trata-se de um estudo longitudinal realizado no centro de promoção da saúde de um hospital universitário. Nove gestantes e 12 não gestantes participaram do estudo. Foram coletados e analisados soro e UWS nos três trimestres gestacionais e duas vezes por mês durante o ciclo menstrual. A análise do cortisol salivar e sérico foi realizada com o uso de quimiluminescência e a atividade da sAA foi determinada por meio de analisador automático para bioquímica. RESULTADOS: Foi verificado que a mediana (intervalo interquartil) dos níveis de cortisol sérico no grupo de gestantes foi maior que 23,8 µL/dL (19,4-29,4) quando comparado ao grupo de não gestantes, que teve média de 12,3 (9,6-16,8; p<0,001). Os níveis de sAA seguiram o mesmo padrão, com médias de 56,7 U/L (30,9-82,2) e 31,8 (18,1-53,2; p<0,001), respectivamente. Foram observadas diferenças dos níveis de cortisol sérico e salivar (µL/dL) e de sAA entre a fase folicular versus a fase lútea (p<0,001). As medianas dos fluxos salivares (UWS) foram semelhantes em gestantes (0,26 [0,15-0,30] mL/min) e não gestantes (0,23 [0,20-0,32] mL/min). Foram encontradas correlações significativas entre o cortisol salivar e o sérico (p=0,02) e entre o cortisol salivar e a sAA (p=0,01). CONCLUSÕES: Os níveis de cortisol sérico de sAA durante a gestação elevam-se. Na fase lútea do ciclo ovariano, os níveis de cortisol salivar aumentam ao passo que os níveis de cortisol sérico e sAA diminuem. _______________________________________________________________________________________ ABSTRACT