13,151 research outputs found

    The morphologic variability in atrioventricular valvar atresia

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    Stroke Survivors Who Score below Threshold on Standard Depression Measures May Still Have Negative Cognitions of Concern

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    Background and Purpose— There has been an increase in screening for depression in the physically ill. We explored whether important negative cognitions may be missed by conventional approaches to screening for depression in 2 independently conducted stroke studies with similar methods. Methods— The Auckland Regional Community Stroke (ARCOS) study was a prospective, population-based stroke incidence study conducted in Auckland, New Zealand, for 12 months in 2002 to 2003. The Stroke Outcomes Study was a prospective, hospital cohort study conducted in Leeds and Bradford, United Kingdom, for 33 months in 2002 to 2005. Symptoms of abnormal mood were assessed at 6 months in ARCOS with a single simple question, “Do you often feel sad and depressed?” and the 28-item General Health Questionnaire administered as part of a structured interview and in the Stroke Outcomes Study with the 28-item General Health Questionnaire and a single question about depressed mood taken from the Present State Examination. Results— Mood data were available at 6 months from 770 ARCOS and 492 Stroke Outcomes Study participants. A significant proportion (up to 28%) of people who did not meet study criteria for depression reported important negative cognitions such as hopelessness, worthlessness, or suicidality. People who were older, dependent in activities of daily living, or not partnered were more likely to report negative cognitions. Conclusions— Important negative cognitions, including suicidal thoughts, may be missed when people are screened for depression after stroke. Screening alone is not an adequate substitute for a sensitive exploration of the psychological impact of stroke on the survivor

    Decoupling of morphological disparity and taxic diversity during the adaptive radiation of anomodont therapsids

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    Adaptive radiations are central to macroevolutionary theory. Whether triggered by acquisition of new traits or ecological opportunities arising from mass extinctions, it is debated whether adaptive radiations are marked by initial expansion of taxic diversity or of morphological disparity (the range of anatomical form). If a group rediversifies following a mass extinction, it is said to have passed through a macroevolutionary bottleneck, and the loss of taxic or phylogenetic diversity may limit the amount of morphological novelty that it can subsequently generate. Anomodont therapsids, a diverse clade of Permian and Triassic herbivorous tetrapods, passed through a bottleneck during the end-Permian mass extinction. Their taxic diversity increased during the Permian, declined significantly at the Permo–Triassic boundary and rebounded during the Middle Triassic before the clade's final extinction at the end of the Triassic. By sharp contrast, disparity declined steadily during most of anomodont history. Our results highlight three main aspects of adaptive radiations: (i) diversity and disparity are generally decoupled; (ii) models of radiations following mass extinctions may differ from those triggered by other causes (e.g. trait acquisition); and (iii) the bottleneck caused by a mass extinction means that a clade can emerge lacking its original potential for generating morphological variety

    Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O

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    Although the microscopic origin of the superconductivity in high Tc copper oxides remains the subject of active inquiry, several of their electronic characteristics are well established as universal to all the known materials, forming the experimental foundation that all theories must address. The most fundamental of those characteristics is the dependence of the superconducting transition temperature on the degree of electronic band filling. Since the discovery of cuprate superconductivity in 1986 (1), the search for other families of superconductors that might help shed light on the superconducting mechanism of the cuprates has been of great interest. The recent report of superconductivity near 4K in the triangular lattice, layered sodium cobalt oxyhydrate, Na0.35CoO2.1.3H2O, is the best indication that superconductors related to the cuprates may be found (2). Here we show that the superconducting transition temperature of this compound displays the same kind of band-filling behavior that is observed in the cuprates. Specifically, that the optimal superconducting Tc occurs in a narrow range of band filling, and decreases for both underdoped and overdoped materials, in dramatic analogy to the phase diagram of the cuprate superconductors. Our results suggest that characterization of the detailed electronic and magnetic behavior of these new materials may help establish which of the many special characteristics of the cuprates is fundamental to their high Tc superconductivity.Comment: revised, publication information adde

    Markov chain aggregation and its application to rule-based modelling

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    Rule-based modelling allows to represent molecular interactions in a compact and natural way. The underlying molecular dynamics, by the laws of stochastic chemical kinetics, behaves as a continuous-time Markov chain. However, this Markov chain enumerates all possible reaction mixtures, rendering the analysis of the chain computationally demanding and often prohibitive in practice. We here describe how it is possible to efficiently find a smaller, aggregate chain, which preserves certain properties of the original one. Formal methods and lumpability notions are used to define algorithms for automated and efficient construction of such smaller chains (without ever constructing the original ones). We here illustrate the method on an example and we discuss the applicability of the method in the context of modelling large signalling pathways

    Who the hell was that? Stories, bodies and actions in the world

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    This article explores a two-way relationship between stories and the experiential actions of bodies in the world. Through an autoethnographic approach, the article presents a series of interlinked story fragments in an effort to show and evoke a feel for the ways in which stories, bodies, and actions influence and shape each other over time. It offers some reflections on the experiences the stories portray from the perspective of a social constructionist conception of narrative theory and suggest that while stories exert a powerful influence on the actions of our bodies, our bodies intrude on or ‘talk back’ to this process because bodies have an existence beyond stories

    A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples

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    It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories

    Compressibility of titanosilicate melts

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    The effect of composition on the relaxed adiabatic bulk modulus (K0) of a range of alkali- and alkaline earth-titanosilicate [X 2 n/n+ TiSiO5 (X=Li, Na, K, Rb, Cs, Ca, Sr, Ba)] melts has been investigated. The relaxed bulk moduli of these melts have been measured using ultrasonic interferometric methods at frequencies of 3, 5 and 7 MHz in the temperature range of 950 to 1600°C (0.02 Pa s < s < 5 Pa s). The bulk moduli of these melts decrease with increasing cation size from Li to Cs and Ca to Ba, and with increasing temperature. The bulk moduli of the Li-, Na-, Ca- and Ba-bearing metasilicate melts decrease with the addition of both TiO2 and SiO2 whereas those of the K-, Rb- and Cs-bearing melts increase. Linear fits to the bulk modulus versus volume fraction of TiO2 do not converge to a common compressibility of the TiO2 component, indicating that the structural role of TiO2 in these melts is dependent on the identity of the cation. This proposition is supported by a number of other property data for these and related melt compositions including heat capacity and density, as well as structural inferences from X-ray absorption spectroscopy (XANES). The compositional dependence of the compressibility of the TiO2 component in these melts explains the difficulty incurred in previous attempts to incorporate TiO2 in calculation schemes for melt compressibility. The empirical relationship KV-4/3 for isostructural materials has been used to evaluate the compressibility-related structural changes occurring in these melts. The alkali metasilicate and disilicate melts are isostructural, independent of the cation. The addition of Ti to the metasilicate composition (i.e. X2TiSiO5), however, results in a series of melts which are not isostructural. The alkaline-earth metasilicate and disilicate compositions are not isostructural, but the addition of Ti to the metasilicate compositions (i.e. XTiSiO5) would appear, on the basis of modulus-volume systematics, to result in the melts becoming isostructural with respect to compressibility

    Modeling Operator Behavior in the Safety Analysis of Collaborative Robotic Applications

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    Human-Robot Collaboration is increasingly prominent in peo- ple's lives and in the industrial domain, for example in manufacturing applications. The close proximity and frequent physical contacts between humans and robots in such applications make guaranteeing suitable levels of safety for human operators of the utmost importance. Formal veri- cation techniques can help in this regard through the exhaustive explo- ration of system models, which can identify unwanted situations early in the development process. This work extends our SAFER-HRC method- ology with a rich non-deterministic formal model of operator behaviors, which captures the hazardous situations resulting from human errors. The model allows safety engineers to rene their designs until all plausi- ble erroneous behaviors are considered and mitigated

    Determining the date of diagnosis – is it a simple matter? The impact of different approaches to dating diagnosis on estimates of delayed care for ovarian cancer in UK primary care

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    Background Studies of cancer incidence and early management will increasingly draw on routine electronic patient records. However, data may be incomplete or inaccurate. We developed a generalisable strategy for investigating presenting symptoms and delays in diagnosis using ovarian cancer as an example. Methods The General Practice Research Database was used to investigate the time between first report of symptom and diagnosis of 344 women diagnosed with ovarian cancer between 01/06/2002 and 31/05/2008. Effects of possible inaccuracies in dating of diagnosis on the frequencies and timing of the most commonly reported symptoms were investigated using four increasingly inclusive definitions of first diagnosis/suspicion: 1. "Definite diagnosis" 2. "Ambiguous diagnosis" 3. "First treatment or complication suggesting pre-existing diagnosis", 4 "First relevant test or referral". Results The most commonly coded symptoms before a definite diagnosis of ovarian cancer, were abdominal pain (41%), urogenital problems(25%), abdominal distension (24%), constipation/change in bowel habits (23%) with 70% of cases reporting at least one of these. The median time between first reporting each of these symptoms and diagnosis was 13, 21, 9.5 and 8.5 weeks respectively. 19% had a code for definitions 2 or 3 prior to definite diagnosis and 73% a code for 4. However, the proportion with symptoms and the delays were similar for all four definitions except 4, where the median delay was 8, 8, 3, 10 and 0 weeks respectively. Conclusion Symptoms recorded in the General Practice Research Database are similar to those reported in the literature, although their frequency is lower than in studies based on self-report. Generalisable strategies for exploring the impact of recording practice on date of diagnosis in electronic patient records are recommended, and studies which date diagnoses in GP records need to present sensitivity analyses based on investigation, referral and diagnosis data. Free text information may be essential in obtaining accurate estimates of incidence, and for accurate dating of diagnoses
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