837 research outputs found

    A system for synthetic vision and augmented reality in future flight decks

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    Rockwell Science Center is investigating novel human-computer interaction techniques for enhancing the situational awareness in future flight decks. One aspect is to provide intuitive displays that provide the vital information and the spatial awareness by augmenting the real world with an overlay of relevant information registered to the real world. Such Augmented Reality (AR) techniques can be employed during bad weather scenarios to permit flying in Visual Flight Rules (VFR) in conditions which would normally require Instrumental Flight Rules (IFR). These systems could easily be implemented on heads-up displays (HUD). The advantage of AR systems vs. purely synthetic vision (SV) systems is that the pilot can relate the information overlay to real objects in the world, whereas SV systems provide a constant virtual view, where inconsistencies can hardly be detected. The development of components for such a system led to a demonstrator implemented on a PC. A camera grabs video images which are overlaid with registered information. Orientation of the camera is obtained from an inclinometer and a magnetometer; position is acquired from GPS. In a possible implementation in an airplane, the on-board attitude information can be used for obtaining correct registration. If visibility is sufficient, computer vision modules can be used to fine-tune the registration by matching visual cues with database features. This technology would be especially useful for landing approaches. The current demonstrator provides a frame-rate of 15 fps, using a live video feed as background with an overlay of avionics symbology in the foreground. In addition, terrain rendering from a 1 arc sec. digital elevation model database can be overlaid to provide synthetic vision in case of limited visibility. For true outdoor testing (on ground level), the system has been implemented on a wearable computer

    Atypical case of post-partum cardiomyopathy: an overlap syndrome with arrhythmogenic right ventricular cardiomyopathy?

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    A middle-aged female patient presented with increasing dyspnoea following delivery of her second child. Echocardiography showed left ventricular (LV) dilatation and severe global impairment of systolic function (ejection fraction < 10%) but normal right ventricular (RV) dimensions. Plasma B-type natriuretic peptide level was elevated. Post-partum cardiomyopathy (PPCM) was considered and after initiating appropriate heart failure pharmacotherapy, her symptoms improved significantly. Cardiovascular MR showed RV free wall dyskinesia and aneurysms at the LV apex, RV free wall and RV outflow tract. Genetic analysis showed a C11842T substitution in the titin gene (TTN). This is the first case to propose an overlap syndrome of PPCM and arrhythmogenic RV cardiomyopathy.published_or_final_versio

    The fast multipole method (FMM) for electromagnetic scattering problems

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    Adjuvant Chemoradiation Therapy in Gastric Cancer: Critically Reviewing the Past and Visualizing the Next Step Forward

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    none9Gastric cancer remains one of the most common malignancies worldwide. Despite the significant advances in surgical treatment and multimodality strategies, prognosis has modestly improved over the last two decades. Locoregional relapse remains one of the main issues and the combined chemoradiation treatment seems to be one of the preferred approaches. However, more than ten years after the hallmark INT-0116 trial, minimal progress has been made both in terms of effectiveness and toxicity. Moreover, new regimens added to combined therapy failed to prove favourable results. Herein, we attempt a thorough literature review comparing pros and cons of all relative studies and potential bias, targeting well-designed future approaches.openPapadimitriou K.; Antoniou G.; Rolfo C.; Russo A.; Bronte G.; Vassiliou V.; Papamichael D.; Peeters M.; Kountourakis P.Papadimitriou, K.; Antoniou, G.; Rolfo, C.; Russo, A.; Bronte, G.; Vassiliou, V.; Papamichael, D.; Peeters, M.; Kountourakis, P

    Solar flares with and without SOHO/LASCO coronal mass ejections and type II shocks

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    We analyse of a set of radio rich (accompanied by type IV or II bursts) solar flares and their association with SOHO/LASCO Coronal Mass Ejections in the period 1998 2000. The intensity, impulsiveness and energetics of these events are investigated. We find that, on the average, flares associated both with type IIs and CMEs are more impulsive and more energetic than flares associated with type IIs only (without CME reported), as well as flares accompanied by type IV continua but not type II shocks. From the last two classes, flares with type II bursts (without CMEs reported) are the shortest in duration and the most impulsive.Comment: Advances in Space Research, Volume 38, Issue 5, p. 1007-101

    The occurrence of Rhynchophorus ferrugineus in Greece and Cyprus and the risk against the native greek palm tree Phoenix theophrasti

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    Ο κόκκινος ρυγχωτός κάνθαρος των φοινικοειδο')ν, Rhynchophorus ferrugineus (Coleoptera: Curculionidae), είναι ο σημαντικότερος εχθρός των φοινικσειδών παγκοσμίως. Την τελευταία δεκαετία εισέβαλε στις Μεσογειακές χώρες προκαλώντας σοβαρές ζημιές σε καλλιέργειες χουρμαδιάς καθώς και σε καλλωπιστικά φοινινοειδή. Το R. ferrugineus βρέθηκε για πρώτη φορά στην Ελλάδα το Νοέμβριο 2005 στη Χερσόνησο (Νομός Ηρακλείου, Κρήτη) επί Phoenix canariensis και για πρώτη φορά στην Κύπρο στη Λεμεσό τον Αύγουστο 2006 επίσης επί Ρ. canariensis. Εν συνεχεία το R. ferrugineus βρέθηκε στην Ελλάδα, προσβάλλοντας κατά κανόνα P. canariensis, σε Ρόδο (Σεπτέμβριος 2006), Ωρωπό και Βλληνικό Αττικής (Δεκέμβριος 2006). Στην Κύπρο βρέθηκε επίσης τον Οκτώβριο 2006 σε Λάρνακα, Αμμόχωστο και Πάφο, Σε πειραματική δοκιμή στο εργαστήριο, στο Μπενάκειο Φυτοπαθολογικό Ινστιτούτο, διαπιστό)θηκε ότι το R. ferrugineus μπορεί να προσβάλλει και να καταστρέψει και το ιθαγενές είδος φοίνικα Phoenix theophrasti.The red palm weevil (RPW), Rhynchophorus ferrugineus (Coleopiera: Curculionidae), is the most important pest of palm trees in the world. In the last decade R. ferrugineus has invaded the Mediterranean basin where it causes severe damage in date palm cultivations as well as in ornamental palm trees. R. ferrugineus has been found for first time in Greece in Hersonissos (Heraklion district, Crete) infesting Phoenix canariensis, on November 11th, 2005 and for first time in Cyprus in Limassol district on August 20th, 2006, infesting also P. canariensis. Afterwards, R. ferrugineus has been found in Rhodos island, Greece, on 15/9/2006 and in Oropos and Ellinikon (Attiki district, Greece) on 5/12/2006 and 27/12/2006 respectively, infesting mainly P. canariensis. In Cyprus it has also been found in October 2006 in Larnaca, Famagusta and Paphos districts. In laboratory experimentation the susceptibility of the native Greek palm tree Phoenix theophrasti in R. ferrugineus was proved

    Internal jugular vein duplication: clinical significance for head and neck cancer ablative and reconstructive surgery

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    We present the case of a 75-year-old patient with a T2N0Mo oral cancer, who underwent surgery for cancer ablation and reconstruction. Intraoperatively, a duplicate internal jugular vein (IJV) was identified. Both segments were preserved. The veins of the free radial forearm flap that was used to reconstruct the defect were anastomosed to tributaries of the anterior IJV segment. In this rare anatomical variation, the anterior segment of IJV lies medially/anteriorly to the sternocleidomastoid muscle which poses a risk of inadvertent injury during the early steps of the neck dissection (ND). The posterior segment is at risk of injury during developing levels II–III–IV of ND. It is important to preserve the anterior IJV segment as this receives all tributaries that can be used for end-to-end anastomosis for the free flap. Preoperative contrast computed tomography scan can aid in recognition of IJV duplication and help prepare the surgeon to adjust certain operative steps

    Combined influence of B-cell receptor rearrangement and somatic hypermutation on B-cell class-switch fate in health and in chronic lymphocytic leukaemia

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    A diverse B-cell receptor (BCR) repertoire is required to bind a wide range of antigens. BCRs are generated through genetic recombination and can be diversified through somatic hypermutation (SHM) or class-switch recombination (CSR). Patterns of repertoire diversity can vary substantially between different health conditions. We use isotyperesolved BCR sequencing to compare B-cell evolution and class-switch fate in healthy individuals and in patients with chronic lymphocytic leukemia (CLL). We show that the patterns of SHM and CSR in B-cells from healthy individuals are distinct from CLL. We identify distinct properties of clonal expansion that lead to the generation of antibodies of different classes in healthy, malignant, and non-malignant CLL BCR repertoires. We further demonstrate that BCR diversity is affected by relationships between antibody variable and constant regions leading to isotype-specific signatures of variable gene usage. This study provides powerful insights into the mechanisms underlying the evolution of the adaptive immune responses in health and their aberration during disease

    Atrial fibrillation in embolic stroke of undetermined source: role of advanced imaging of left atrial function

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    \ua9 The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. AIMS: Atrial fibrillation (AF) is detected in over 30% of patients following an embolic stroke of undetermined source (ESUS) when monitored with an implantable loop recorder (ILR). Identifying AF in ESUS survivors has significant therapeutic implications, and AF risk is essential to guide screening with long-term monitoring. The present study aimed to establish the role of left atrial (LA) function in subsequent AF identification and develop a risk model for AF in ESUS. METHODS AND RESULTS: We conducted a single-centre retrospective case-control study including all patients with ESUS referred to our institution for ILR implantation from December 2009 to September 2019. We recorded clinical variables at baseline and analysed transthoracic echocardiograms in sinus rhythm. Univariate and multivariable analyses were performed to inform variables associated with AF. Lasso regression analysis was used to develop a risk prediction model for AF. The risk model was internally validated using bootstrapping. Three hundred and twenty-three patients with ESUS underwent ILR implantation. In the ESUS population, 293 had a stroke, whereas 30 had suffered a transient ischaemic attack as adjudicated by a senior stroke physician. Atrial fibrillation of any duration was detected in 47.1%. The mean follow-up was 710 days. Following lasso regression with backwards elimination, we combined increasing lateral PA (the time interval from the beginning of the P wave on the surface electrocardiogram to the beginning of the A\u27 wave on pulsed wave tissue Doppler of the lateral mitral annulus) [odds ratio (OR) 1.011], increasing Age (OR 1.035), higher Diastolic blood pressure (OR 1.027), and abnormal LA reservoir Strain (OR 0.973) into a new PADS score. The probability of identifying AF can be estimated using the formula. Model discrimination was good [area under the curve (AUC) 0.72]. The PADS score was internally validated using bootstrapping with 1000 samples of 150 patients showing consistent results with an AUC of 0.73. CONCLUSION: The novel PADS score can identify the risk of AF on prolonged monitoring with ILR following ESUS and should be considered a dedicated risk stratification tool for decision-making regarding the screening strategy for AF in stroke.One-third of patients with a type of stroke called embolic stroke of undetermined source (ESUS) also have a heart condition called atrial fibrillation (AF), which increases their risk of having another stroke. However, we do not know why some patients with ESUS develop AF. To figure this out, we studied 323 patients with ESUS and used a special device to monitor their heart rhythm continuously for up to 3 years, an implantable loop recorder. We also looked at their medical history, performed a heart ultrasound, and identified some factors that increase the risk of identifying AF in the future. Factors associated with future AF include older age, higher diastolic blood pressure, and problems with the co-ordination and function of the upper left chamber of the heart called the left atrium.Based on these factors, we created a new scoring system that can identify patients who are at higher risk of developing AF better than the current scoring systems, the PADS score. This can potentially help doctors provide more targeted and effective treatment to these patients, ultimately aiming to reduce their risk of having another stroke
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