413 research outputs found

    Virtual Exploration of Underwater Archaeological Sites : Visualization and Interaction in Mixed Reality Environments

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    This paper describes the ongoing developments in Photogrammetry and Mixed Reality for the Venus European project (Virtual ExploratioN of Underwater Sites, http://www.venus-project.eu). The main goal of the project is to provide archaeologists and the general public with virtual and augmented reality tools for exploring and studying deep underwater archaeological sites out of reach of divers. These sites have to be reconstructed in terms of environment (seabed) and content (artifacts) by performing bathymetric and photogrammetric surveys on the real site and matching points between geolocalized pictures. The base idea behind using Mixed Reality techniques is to offer archaeologists and general public new insights on the reconstructed archaeological sites allowing archaeologists to study directly from within the virtual site and allowing the general public to immersively explore a realistic reconstruction of the sites. Both activities are based on the same VR engine but drastically differ in the way they present information. General public activities emphasize the visually and auditory realistic aspect of the reconstruction while archaeologists activities emphasize functional aspects focused on the cargo study rather than realism which leads to the development of two parallel VR demonstrators. This paper will focus on several key points developed for the reconstruction process as well as both VR demonstrators (archaeological and general public) issues. The ?rst developed key point concerns the densi?cation of seabed points obtained through photogrammetry in order to obtain high quality terrain reproduction. The second point concerns the development of the Virtual and Augmented Reality (VR/AR) demonstrators for archaeologists designed to exploit the results of the photogrammetric reconstruction. And the third point concerns the development of the VR demonstrator for general public aimed at creating awareness of both the artifacts that were found and of the process with which they were discovered by recreating the dive process from ship to seabed

    Prognostic value of a modified surprise question designed for use in the emergency department setting.

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    OBJECTIVE: Few reliable and valid prognostic tools are available to help emergency physicians identify patients who might benefit from early palliative approaches. We sought to determine if responses to a modified version of the surprise question, Would you be surprised if this patient died in the next 30 days could predict in-hospital mortality and resource utilization for hospitalized emergency department patients. METHODS: For this observational study, emergency physicians responded to the modified surprise question with each admission over a five-month study period. Logistic regression analyses were completed and standard test characteristics evaluated. RESULTS: 6,122 visits were evaluated. Emergency physicians responded negatively to the modified surprise question in 918 (15.1%). Test characteristics for in-hospital mortality were: sensitivity 32%, specificity 85%, positive predictive value 6%, negative predictive value 98%. The risk of intensive care unit use (relative risk [RR], 1.87; 95% confidence interval [CI], 1.45 to 2.40), use of \u27comfort measures\u27 orders (RR, 3.43; 95% CI, 2.81 to 4.18), palliative-care consultation (RR, 3.06; 95% CI, 2.62 to 3.56), and in-hospital mortality (RR, 2.18; 95% CI, 1.72 to 2.76) were greater for patients with negative responses. CONCLUSION: The modified surprise question is a simple trigger for palliative care needs, accurately identifying those at greater risk for in-hospital mortality and resource utilization. With a negative predictive value of 98%, affirmative responses to the modified surprise question provide reassurance that in-hospital death is unlikely

    Examining the Relationship Between Markers of Emergency Department Crowding and Physician Wellbeing

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    Objectives- Explore changes to EP wellbeing over time. Evaluate the relationships between markers of ED crowding and boarding and EP wellbeinghttps://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1013/thumbnail.jp

    Distinguishing sequences for partially specified FSMs

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    Distinguishing Sequences (DSs) are used inmany Finite State Machine (FSM) based test techniques. Although Partially Specified FSMs (PSFSMs) generalise FSMs, the computational complexity of constructing Adaptive and Preset DSs (ADSs/PDSs) for PSFSMs has not been addressed. This paper shows that it is possible to check the existence of an ADS in polynomial time but the corresponding problem for PDSs is PSPACE-complete. We also report on the results of experiments with benchmarks and over 8 * 106 PSFSMs. © 2014 Springer International Publishing

    Generating a checking sequence with a minimum number of reset transitions

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    Given a finite state machine M, a checking sequence is an input sequence that is guaranteed to lead to a failure if the implementation under test is faulty and has no more states than M. There has been much interest in the automated generation of a short checking sequence from a finite state machine. However, such sequences can contain reset transitions whose use can adversely affect both the cost of applying the checking sequence and the effectiveness of the checking sequence. Thus, we sometimes want a checking sequence with a minimum number of reset transitions rather than a shortest checking sequence. This paper describes a new algorithm for generating a checking sequence, based on a distinguishing sequence, that minimises the number of reset transitions used.This work was supported in part by Leverhulme Trust grant number F/00275/D, Testing State Based Systems, Natural Sciences and Engineering Research Council (NSERC) of Canada grant number RGPIN 976, and Engineering and Physical Sciences Research Council grant number GR/R43150, Formal Methods and Testing (FORTEST)

    Response of a low elevation carbonate lake in the Yucatan Peninsula (Mexico) to climatic and human forcings

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    The importance of climate change, specifically drought, across the Maya region in the northern Neotropics, remains a topic of lively debate. Part of this discussion hinges on the coherency of response to climatic variability across different archives and proxies. In this paper we present a 6600-year palaeolimnological record from Yaal Chac, a carbonate lake (known locally as a cenote) in the northern lowlands of the Yucatan Peninsula, 2‰), but show no covariation with δ13C. A major transition occurs at ca. 4360 cal yr BP, with a change to generally more organic sediments and increased variability in all proxies. Although direct evidence for anthropogenic activity in the Yaal Chac catchment is limited, it seems feasible that human impact was affecting the system. Comparison with other records from the Northern Maya lowlands and the wider region shows little coherence in the mid Holocene, when Yaal Chac seems to have been quite stable, but possibly responsive to increased climatic seasonality, driving the production of seasonal laminae. In the late Holocene, when the climate was generally more variable, there is more coherence between Yaal Chac and other regional records, including the so called Pan Caribbean Dry Period (3500–2500 cal yr BP) and the droughts of the late Pre-Classic period (1800–1600 cal yr BP). The Yaal Chac record shows no evidence of drought at the time of either the Maya ‘hiatus’ or the Maya ‘collapse’ of the Terminal Classic, but does record drying from the 14th to 19th centuries CE, in keeping with other proxy and historical records. This new record from Yaal Chac highlights the spatial variability of responses to climate forcings and the importance of recognising individual system sensitivity

    Insights into GABA receptor signalling in TM3 Leydig cells

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    gamma-Aminobutyric acid (GABA) is an emerging signalling molecule in endocrine organs, since it is produced by endocrine cells and acts via GABA(A) receptors in a paracrine/autocrine fashion. Testicular Leydig cells are producers and targets for GABA. These cells express GABA(A) receptor subunits and in the murine Leydig cell line TM3 pharmacological activation leads to increased proliferation. The signalling pathway of GABA in these cells is not known in this study. We therefore attempted to elucidate details of GABA(A) signalling in TM3 and adult mouse Leydig cells using several experimental approaches. TM3 cells not only express GABA(A) receptor subunits, but also bind the GABA agonist {[}H-3] muscimol with a binding affinity in the range reported for other endocrine cells (K-d = 2.740 +/- 0.721 nM). However, they exhibit a low B-max value of 28.08 fmol/mg protein. Typical GABA(A) receptor-associated events, including Cl- currents, changes in resting membrane potential, intracellular Ca2+ or cAMP, were not measurable with the methods employed in TM3 cells, or, as studied in part, in primary mouse Leydig cells. GABA or GABA(A) agonist isoguvacine treatment resulted in increased or decreased levels of several mRNAs, including transcription factors (c-fos, hsf-1, egr-1) and cell cycle-associated genes (Cdk2, cyclin D1). In an attempt to verify the cDNA array results and because egr-1 was recently implied in Leydig cell development, we further studied this factor. RT-PCR and Western blotting confirmed a time-dependent regulation of egr-1 in TM3. In the postnatal testis egr-1 was seen in cytoplasmic and nuclear locations of developing Leydig cells, which bear GABA(A) receptors and correspond well to TM3 cells. Thus, GABA acts via an untypical novel signalling pathway in TM3 cells. Further details of this pathway remain to be elucidated. Copyright (c) 2005 S. Karger AG, Base

    Prognostic value of a modified surprise question designed for use in the emergency department setting

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    Objective Few reliable and valid prognostic tools are available to help emergency physicians identify patients who might benefit from early palliative approaches. We sought to determine if responses to a modified version of the surprise question, “Would you be surprised if this patient died in the next 30 days” could predict in-hospital mortality and resource utilization for hospitalized emergency department patients. Methods For this observational study, emergency physicians responded to the modified surprise question with each admission over a five-month study period. Logistic regression analyses were completed and standard test characteristics evaluated. Results 6,122 visits were evaluated. Emergency physicians responded negatively to the modified surprise question in 918 (15.1%). Test characteristics for in-hospital mortality were: sensitivity 32%, specificity 85%, positive predictive value 6%, negative predictive value 98%. The risk of intensive care unit use (relative risk [RR], 1.87; 95% confidence interval [CI], 1.45 to 2.40), use of ‘comfort measures’ orders (RR, 3.43; 95% CI, 2.81 to 4.18), palliative-care consultation (RR, 3.06; 95% CI, 2.62 to 3.56), and in-hospital mortality (RR, 2.18; 95% CI, 1.72 to 2.76) were greater for patients with negative responses. Conclusion The modified surprise question is a simple trigger for palliative care needs, accurately identifying those at greater risk for in-hospital mortality and resource utilization. With a negative predictive value of 98%, affirmative responses to the modified surprise question provide reassurance that in-hospital death is unlikely

    Pediatric Cerebral Palsy in Africa: Where Are We?

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    Cerebral palsy is the most common cause of physical disability in children worldwide. However, little is reported on this condition in the African context. Doctors from 22 countries in Africa, and representatives from a further 5 countries outside Africa, met to discuss the challenges in the evaluation and management of children with cerebral palsy in Africa and to propose service needs and further research. Basic care is limited by the poor availability of diagnostic facilities or medical personnel with experience and expertise in managing cerebral palsy, exacerbated by lack of available interventions such as medications, surgical procedures, or even regular therapy input. Relevant guidelines are lacking. In order to guide services for children with existing disabilities, to effectively target the main etiologies and to develop preventive strategies for the continent, research priorities must include multicenter collaborative studies looking at the prevalence, risk factors, and treatment of cerebral palsy
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