881 research outputs found

    Two-dimensional discrete wavelet analysis of multiparticle event topology in heavy ion collisions

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    The event-by-event analysis of multiparticle production in high energy hadron and nuclei collisions can be performed using the discrete wavelet transformation. The ring-like and jet-like structures in two-dimensional angular histograms are well extracted by wavelet analysis. For the first time the method is applied to the jet-like events with background simulated by event generators, which are developed to describe nucleus-nucleus collisions at LHC energies. The jet positions are located quite well by the discrete wavelet transformation of angular particle distribution even in presence of strong background.Comment: 6 pages, 6 figure

    HEAVY METALS IN URBAN PARK SOILS FROM ATHENS, GREECE

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    Η αστική γεωχημεία είναιένας επιστημονικός κλάδος ο οποίος αναπτύσσεταιτα τελευταία χρόνια κυρίως λόγω των περιβαλλοντικών επιπτώσεων που προκύπτουν από την αστικοποίηση. Η παρούσα εργασία έχει ως στόχο τον προσδιορισμό των συγκεντρώσεων δυνητικά επιβλαβών στοιχείων (PHEs) των επιφανειακών (0-10 cm) εδαφών προερχόμενων από αλσύλια της Αθήνας. Η δειγματοληψία υπαίθρου πραγματοποιήθηκε σε 20 αλσύλια της Αττικής και κάλυψε συνολική έκταση περίπου 200km2 . Αναλύθηκαν 20 εδαφικά δείγματα κοκκομετρίας Mn >Ni≈ Cu≈ Zn> Cr. Τα δεδομένα της έρευνας υποδεικνύουν ότι το έδαφος των αλσυλίων μπορεί να είναι ένας σημαντικός ταμιευτήρας των ανθρωπογενών στοιχείων στο αστικό έδαφοςUrban geochemistry is a scientific discipline which is growing in the recent years mainly because of the environmental impact caused by urbanization. The present study aims to determine the concentrations of potentially harmful elements (PHEs) on surface soils (0-10cm) in Athens parks. Soil sampling was carried out in public park areas within the Athens urban area. Twenty surface soil (0-10cm) samples were collected and the Mn >Ni≈ Cu≈ Zn> Cr. The data indicate that park areas seem to be important sinks of anthropogenic elements in urban soils

    ART – BASED TRAINING METHODS FOR EMPOWERING ADULTS IN THE DIGITAL ERA

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    Since the dawn of humanity, dancing has been central to life occasions, for celebration, mourning, entertaining or even communicating. Still, it remains a vital practice around the world. With the development of technology, many efforts have been made to adapt specific choreographies and dancing rituals to the modern era, via digital platforms. However, these sequences cannot be construed as realistic when they are viewed through computers, because the actual expressions are lost in the translation. A lot of attempts have been made to provide a solution to this issue, but the most successful are the motion capturing devices and equipment. In this research, we focus on the recording of choreographies, which represent important social concepts, using a Microsoft Kinect sensor as a motion capturing device. Microsoft Kinect is chosen because it is a low-cost device that can deliver adequate results. The outcome of the research is a “handbook” in virtual reality environment, which can be used as an educational tool by anyone. The project aims at being a response to the global need of today’s world for creation of inclusive environments, where socially aware people can peacefully co – exist. The digital handbook can enhance the skills and competences of adult trainers in arts and culture and every participant gets in touch with sensitive concepts and develops social awareness. Inspiration for the project is drawn via social and humanistic values stemming from philosophical, sociological and psychological texts and it is innovative not only for its content but also for the way this is developed

    ACCURATE 3D SCANNING OF DAMAGED ANCIENT GREEK INSCRIPTIONS FOR REVEALING WEATHERED LETTERS

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    In this paper two non-invasive non-destructive alternative techniques to the traditional and invasive technique of squeezes are presented alongside with specialized developed processing methods, aiming to help the epigraphists to reveal and analyse weathered letters in ancient Greek inscriptions carved in masonry or marble. The resulting 3D model would serve as a detailed basis for the epigraphists to try to decipher the inscription. The data were collected by using a Structured Light scanner. The creation of the final accurate three dimensional model is a complicated procedure requiring large computation cost and human effort. It includes the collection of geometric data in limited space and time, the creation of the surface, the noise filtering and the merging of individual surfaces. The use of structured light scanners is time consuming and requires costly hardware and software. Therefore an alternative methodology for collecting 3D data of the inscriptions was also implemented for reasons of comparison. Hence, image sequences from varying distances were collected using a calibrated DSLR camera aiming to reconstruct the 3D scene through SfM techniques in order to evaluate the efficiency and the level of precision and detail of the obtained reconstructed inscriptions. Problems in the acquisition processes as well as difficulties in the alignment step and mesh optimization are also encountered. A meta-processing framework is proposed and analysed. Finally, the results of processing and analysis and the different 3D models are critically inspected and then evaluated by a specialist in terms of accuracy, quality and detail of the model and the capability of revealing damaged and ”hidden” letters

    Attentive Learning of Sequential Handwriting Movements: A Neural Network Model

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    Defense Advanced research Projects Agency and the Office of Naval Research (N00014-95-1-0409, N00014-92-J-1309); National Science Foundation (IRI-97-20333); National Institutes of Health (I-R29-DC02952-01)

    Next-generation sequencing refines the genetic architecture of Greek GnRH-deficient patients

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    Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is a rare disease with a wide spectrum of reproductive and non-reproductive clinical characteristics. Apart from the phenotypic heterogeneity, IGD is also highly genetically heterogeneous with >35 genes implicated in the disease. Despite this genetic heterogeneity, genetic enrichment in specific subpopulations has been described. We have previously described low prevalence of genetic variation in the Greek IGD cohort discovered with utilization of Sanger sequencing in 14 known IGD genes. Here, we describe the expansion of genetic screening in the largest IGD Greek cohort that has ever been studied with the usage of whole-exome sequencing, searching for rare sequencing variants (RSVs) in 37 known IGD genes. Even though Sanger sequencing detected genetic variation in 21/81 IGD patients in 7/14 IGD genes without any evidence of oligogenicity, whole exome sequencing (WES) revealed that 27/87 IGD patients carried a rare genetic change in a total of 15 genes with 4 IGD cases being oligogenic. Our findings suggest that next-generation sequencing (NGS) techniques can discover previously undetected variation, making them the standardized method for screening patients with rare and/or more common disorders

    Human pericardium graft in the management of bleb's complication performed in childhood: a case report

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    <p>Abstract</p> <p>Background</p> <p>To report a case with hypotony due to late leakage of the filtering bleb performed during childhood and treated surgically using human pericardium graft.</p> <p>Case Presentation</p> <p>A man with hypotony related to bleb's leakage in his right eye was presented. During his childhood trabeculectomy was performed to manage ocular hypertension due to pediatric glaucoma. Biomicroscopy revealed choroidal tissue incarcerated in the sclerectomy under the conjunctiva. Bleb revision was performed. Human pericardium graft was used to cover the sclerectomy and a new bleb with controlled outflow was created. The intraocular pressure (IOP) and Seidel test represent the main outcomes. Intraoperative and postoperative complications were recorded. Fifteen days postoperatively the IOP was of 7 mmHg and the bleb seemed to filter properly. Five months later the IOP was 9 mmHg and no complications were noticed. During the follow up time, the Seidel test was negative.</p> <p>Conclusion</p> <p>We used human pericardium graft with no complications in a case of bleb leakage performed for pediatric glaucoma.</p

    Preliminary diagnostic reference levels for endoscopic retrograde cholangio-pancreatography in Greece

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    The main objective of this study was to determine the preliminary Diagnostic Reference Levels (DRLs) in terms of Kerma Area Product (KAP) and fluoroscopy time (Tf) during Endoscopic Retrograde Cholangio-Pancreatography (ERCP) procedures. Additionally, an investigation was conducted to explore the statistical relation between KAP and Tf. Data from a set of 200 randomly selected patients treated in 4 large hospitals in Greece (50 patients per hospital) were analyzed in order to obtain preliminary DRLs for KAP and Tf during therapeutic ERCP procedures. Non-parametric statistic tests were performed in order to determine a statistically significant relation between KAP and Tf. The resulting third quartiles for KAP and Tf for hospitals (A, B, C and D) were found as followed: KAPA = 10.7 Gy cm^2, TfA = 4.9 min; KAPB = 7.5 Gy cm^2, TfB = 5.0 min; KAPC = 19.0 Gy cm^2, TfC = 7.3 min; KAPD = 52.4 Gy cm^2, TfD = 15.8 min. The third quartiles, calculated for the total 200 cases sample, are: KAP = 18.8 Gy cm^2 and Tf = 8.2 min. For 3 out of 4 hospitals and for the total sample, p-values of statistical indices (correlation of KAP and Tf) are less than 0.001, while for the Hospital A p-values are ranging from 0.07 to 0.08. Using curve fitting, we finally determine that the relation of Tf and KAP is deriving from a power equation (KAP = Tf^1.282) with R^2 = 0.85. The suggested Preliminary DRLs (deriving from the third quartiles of the total sample) for Greece are: KAP = 19 Gy cm^2 and Tf = 8 min, while the relation between KAP and Tf is efficiently described by a power equatio

    The GATA1s isoform is normally down-regulated during terminal haematopoietic differentiation and over-expression leads to failure to repress MYB, CCND2 and SKI during erythroid differentiation of K562 cells

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    Background: Although GATA1 is one of the most extensively studied haematopoietic transcription factors little is currently known about the physiological functions of its naturally occurring isoforms GATA1s and GATA1FL in humans—particularly whether the isoforms have distinct roles in different lineages and whether they have non-redundant roles in haematopoietic differentiation. As well as being of general interest to understanding of haematopoiesis, GATA1 isoform biology is important for children with Down syndrome associated acute megakaryoblastic leukaemia (DS-AMKL) where GATA1FL mutations are an essential driver for disease pathogenesis. &lt;p/&gt;Methods: Human primary cells and cell lines were analyzed using GATA1 isoform specific PCR. K562 cells expressing GATA1s or GATA1FL transgenes were used to model the effects of the two isoforms on in vitro haematopoietic differentiation. &lt;p/&gt;Results: We found no evidence for lineage specific use of GATA1 isoforms; however GATA1s transcripts, but not GATA1FL transcripts, are down-regulated during in vitro induction of terminal megakaryocytic and erythroid differentiation in the cell line K562. In addition, transgenic K562-GATA1s and K562-GATA1FL cells have distinct gene expression profiles both in steady state and during terminal erythroid differentiation, with GATA1s expression characterised by lack of repression of MYB, CCND2 and SKI. &lt;p/&gt;Conclusions: These findings support the theory that the GATA1s isoform plays a role in the maintenance of proliferative multipotent megakaryocyte-erythroid precursor cells and must be down-regulated prior to terminal differentiation. In addition our data suggest that SKI may be a potential therapeutic target for the treatment of children with DS-AMKL
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