416 research outputs found

    The role of clinical decision support systems in preventing stroke in primary care: a systematic review.

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    Computerized clinical decision support systems (CDSS) are increasingly being used to facilitate the role of clinicians in complex decision-making processes. This systematic review evaluates evidence of the available CDSS developed and tested to support the decision-making process in primary healthcare for stroke prevention and barriers to practical implementations in primary care settings. A systematic search of Web of Science, Medline Ovid, Embase Ovid, and Cinahl was done. A total of five studies, experimental and observational, were synthesised in this review. This review found that CDSS facilitate decision-making processes in primary health care settings in stroke prevention options. However, barriers were identified in designing, implementing, and using the CDSS

    Attosecond time-resolved photoelectron holography

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    Ultrafast strong-field physics provides insight into quantum phenomena that evolve on an attosecond time scale, the most fundamental of which is quantum tunneling. The tunneling process initiates a range of strong field phenomena such as high harmonic generation (HHG), laser-induced electron diffraction, double ionization and photoelectron holography—all evolving during a fraction of the optical cycle. Here we apply attosecond photoelectron holography as a method to resolve the temporal properties of the tunneling process. Adding a weak second harmonic (SH) field to a strong fundamental laser field enables us to reconstruct the ionization times of photoelectrons that play a role in the formation of a photoelectron hologram with attosecond precision. We decouple the contributions of the two arms of the hologram and resolve the subtle differences in their ionization times, separated by only a few tens of attoseconds

    Evaluating earthquake-induced rockfall hazard near the Dead Sea Transform

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    We address an approach for rockfall hazard evaluation where the study area resides below a cliff in an a priori exposure to rockfall hazard, but no historical documentation of rockfall events is available and hence important rockfall hazard parameters like triggering mechanism and recurrence interval are unknown. We study the rockfall hazard for the town of Qiryat Shemona, northern Israel, situated alongside the Dead Sea Transform, at the foot of the Ramim escarpment. Numerous boulders are scattered on the slopes above the town, while pre-town historical aerial photos reveal that boulders had reached the location that is now within town limits. We use field observations and optically stimulated luminescence dating of past rockfall events combined with computer modeling to evaluate the rockfall hazard. For the analysis, we first mapped the rockfall source and final downslope stop sites and compiled the boulder size distribution. We then simulated the possible rockfall trajectories using the field observed data to calibrate the simulation software by comparing simulated and mapped boulder stop sites along selected slopes, while adjusting model input parameters for best fit. The analysis reveals areas of high rockfall hazard at the southwestern quarters of the town and also indicates that in the studied slopes falling blocks would stop where the slope angle decreases below 5–10∘. Age determination suggests that the rockfalls were triggered by large (M&gt;6) historical earthquakes. Nevertheless, not all large historical earthquakes triggered rockfalls. Considering the size distribution of the past rockfalls in the study area and the recurrence time of large earthquakes in the region, we estimate a probability of less than 5&thinsp;% to be affected by a destructive rockfall within a 50-year time window. Here we suggest a comprehensive method to evaluate rockfall hazard where only past rockfall evidence exists in the field. We show the importance of integrating spatial and temporal field observations to assess the extent of rockfall hazard, the potential block size distribution and the rockfall recurrence interval.</p

    Requirements and validation of a prototype learning health system for clinical diagnosis

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    Introduction Diagnostic error is a major threat to patient safety in the context of family practice. The patient safety implications are severe for both patient and clinician. Traditional approaches to diagnostic decision support have lacked broad acceptance for a number of well-documented reasons: poor integration with electronic health records and clinician workflow, static evidence that lacks transparency and trust, and use of proprietary technical standards hindering wider interoperability. The learning health system (LHS) provides a suitable infrastructure for development of a new breed of learning decision support tools. These tools exploit the potential for appropriate use of the growing volumes of aggregated sources of electronic health records. Methods We describe the experiences of the TRANSFoRm project developing a diagnostic decision support infrastructure consistent with the wider goals of the LHS. We describe an architecture that is model driven, service oriented, constructed using open standards, and supports evidence derived from electronic sources of patient data. We describe the architecture and implementation of 2 critical aspects for a successful LHS: the model representation and translation of clinical evidence into effective practice and the generation of curated clinical evidence that can be used to populate those models, thus closing the LHS loop. Results/Conclusions Six core design requirements for implementing a diagnostic LHS are identified and successfully implemented as part of this research work. A number of significant technical and policy challenges are identified for the LHS community to consider, and these are discussed in the context of evaluating this work: medico-legal responsibility for generated diagnostic evidence, developing trust in the LHS (particularly important from the perspective of decision support), and constraints imposed by clinical terminologies on evidence generation

    On the importance of grain size in luminescence dating using quartz

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    There are two major problems commonly encountered when applying Optically Stimulated Luminescence (OSL) dating in the high dose range: (i) age discrepancy between different grain sizes, and (ii) age underestimation. A marked and systematic discrepancy between fine-grain (4–11 μm) and coarse-grain (63–90 μm) quartz single aliquot regeneration protocol (SAR) ages has been reported previously for Romanian and Serbian loess >40 ka (De of ∼100 Gy), generally with fine-grain ages underestimating the depositional age. In this paper, we show a similar age pattern for two grain size fractions from Chinese loess, thus pointing to a potential worldwide phenomenon. While age underestimation is often attributed to signal saturation problems, this is not the case for fine grain material, which saturates at higher doses than coarse grains, yet begins to underestimate true ages earlier. Here we examine the dose response curves of quartz from different sedimentary contexts around the world, using a range of grain sizes (diameters of 4–11 μm, 11–30 μm, 35–50 μm, 63–90 μm, 90–125 μm, 125–180 μm, and 180–250 μm). All dose response curves can be adequately described by a sum of two saturating exponential functions, whose saturation characteristics (D0 values) are clearly anticorrelated with grain diameter (φ) through an inverse square root relationship, D0 = A/√φ, where A is a scaling factor. While the mechanism behind this grain-size dependency of saturation characteristics still needs to be understood, our results show that the observation of an extended SAR laboratory dose response curve does not necessarily enable high doses to be recorded accurately, or provide a corresponding extended age range

    Sialylated N-glycans mediate monocyte uptake of extracellular vesicles secreted from Plasmodium falciparum-infected red blood cells

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    Glycoconjugates on extracellular vesicles (EVs) play a vital role in internalization and mediate interaction as well as regulation of the host immune system by viruses, bacteria, and parasites. During their intraerythrocytic life-cycle stages, malaria parasites, Plasmodium falciparum (Pf) mediate the secretion of EVs by infected red blood cells (RBCs) that carry a diverse range of parasitic and host-derived molecules. These molecules facilitate parasite-parasite and parasite-host interactions to ensure parasite survival. To date, the number of identified Pf genes associated with glycan synthesis and the repertoire of expressed glycoconjugates is relatively low. Moreover, the role of Pf glycans in pathogenesis is mostly unclear and poorly understood. As a result, the expression of glycoconjugates on Pf-derived EVs or their involvement in the parasite life-cycle has yet to be reported. Herein, we show that EVs secreted by Pf-infected RBCs carry significantly higher sialylated complex N-glycans than EVs derived from healthy RBCs. Furthermore, we reveal that EV uptake by host monocytes depends on N-glycoproteins and demonstrate that terminal sialic acid on the N-glycans is essential for uptake by human monocytes. Our results provide the first evidence that Pf exploits host sialylated N-glycans to mediate EV uptake by the human immune system cells

    Persistent Neanderthal occupation of the open-air site of ‘Ein Qashish, Israel

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    Over the last two decades, much of the recent efforts dedicated to the Levantine Middle Paleolithic has concentrated on the role of open-air sites in the settlement system in the region. Here focus on the site of ‘Ein Qashish as a cases study. Located in present-day northern Israel, the area of this site is estimated to have been >1300 m2, of which ca. 670 were excavated. The site is located at the confluence of the Qishon stream with a small tributary running off the eastern flanks of the Mt. Carmel. At the area of this confluence, water channels and alluvial deposits created a dynamic depositional environment. Four Archaeological Units were identified in a 4.5-m thick stratigraphic sequence were dated by Optically Stimulated Luminescence (OSL) to between—71 and 54 ka, and probably shorter time span–~70-~60 ka. Here we present the diverse material culture remains from the site (lithics, including refitted sequences; modified limestone pieces; molluscs; faunal remains) against their changing paleogeographic backdrop. Skeletal evidence suggests that these remains were associated with Neanderthals. The large-scale repeated accumulation of late Middle Paleolithic remains in the same place on the landscape provides a unique opportunity to address questions of occupation duration and intensity in open-air sites. We find that each occupation was of ephemeral nature, yet presents a range of activities, suggesting that the locale has been used as a generalized residential site rather than specialized task-specific ones. This role of ‘Ein Qashish did not change through time, suggesting that during the late Middle Paleolithic settlement system in this part of the southern Levant were stable
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