275 research outputs found

    Blocking techniques for efficient entity resolution over large, highly heterogeneous information spaces

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    Καμπυλότητα Ricci για αλυσίδες Markov σε μετρικούς χώρους

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    Ορίζουμε την coarse καμπυλότητα Ricci ενός μετρικού χώρου, εφοδιασμένου με μια αλυσίδα Markov. Η ιδέα του ορισμού βασίζεται στην παρακάτω ιδιότητα των πολλαπλοτήτων Riemann με θετική καμπυλότητα RIcci: μικρές μπάλες είναι πιο κοντά, ως προς την απόσταση Wasserstein, από ότι τα κέντρα τους. Ο ορισμός είναι συμβατός με τις πολλαπλότητες Riemann, μιας και η coarse καμπυλότητα Ricci είναι η ίδια με την καμπυλότητα Ricci, ως προς αλλαγή κλίμακας. Σε γενικούς χώρους αποδεικνύονται αποτελέσματα όπως ένα θεώρημα φασματικού κενού, ένα Gaussian τύπου θεώρημα συγκέντρωσης του μέτρου, μια εκδοχή μιας λογαριθμικής ανισότητα Sobolev και ένα θεώρημα εκθετικής συγκέντρωσης.We define the coarse Ricci curvature of a metric space, equiped with a Markov chain. The idea behind this definition is based on the following property of a Riemann manifold with positive Ricci curvature: small balls are closer in Wasserstein distance than their centers. On the one hand, this definition is compatible with Riemann manifolds, in which case the coarse Ricci curvature is the same with the Ricci curvature, after a rescaling. On a general setting, it implies a great range of results, such as a spectral gap bound, a Gaussian-type concetration of measure theorem, a version of a logarothmic Sobolev inequality and an exponential concetration theorem

    Pathophysiology and Biomechanics of the Aging Spine

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    Aging of the spine is characterized by two parallel but independent processes: the reduction of bone mineral density and the development of degenerative changes. The combination of degeneration and bone mass reduction contribute, to a different degree, to the development of a variety of lesions. This results in a number of painful and often debilitating disorders. The present review constitutes a synopsis of the pathophysiological processes that take place in the aging spine as well as of the consequences these changes have on the biomechanics of the spine. The authors hope to present a thorough yet brief overview of the process of aging of the human spine

    Shoulder Arthroscopy After a Proximal Humeral Fracture Malunion: Athlete Care and Clinical Medicine in Middle-Aged Athletes

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    Malunion of the proximal humerus is operationally defined as healing of the fractured bone in a non-anatomical position, resulting in a painful and disabling deformity (e.g., a bone being shorter than normal, twisted or rotated in a bad position, or bent), which affects the range of motion (ROM) and functional movement. A correction and functional restoration are often needed in athletes, since their profession requires superior physical functioning. Shoulder arthroscopy has evolved dramatically over the past 15 years and has been used in cases of malunion of the humerus in athletes. However, there is a scarcity of evidence concerning middle-aged athletes. PURPOSE: To examine the benefits of shoulder arthroscopy after a proximal humeral fracture unified in malposition in middle-aged athletes. METHODS: Physical examination and imaging evaluation using 3D Computed Tomography(3D-CT), Magnetic Resonance Imaging (MRI), and shoulder radiographs (anteroposterior, internal rotation, and lateral scapular view) were used to evaluate shoulder dysfunction after proximal humeral fracture in malposition. Fourteen athletes (9 males, 5 females; Mage = 43.1, SD = 3.5) were included in this research. According to Neer classification before surgery, 11 (78%) had one part displaced and the rest three (22%) had two parts displaced. Post-operative clinical results were evaluated with self-reported pain score (1-10), UCLA scores, and shoulder abduction ROM measured with a goniometer. RESULTS: There was significant difference in pain scores (Mbefore = 8, Range: 6-9; Mafter = 4, Range: 2-6; p \u3c .001), in UCLA scores (Mbefore = 12, Range: 9-16; Mafter = 28, Range: 20-31; p \u3c .01), and in shoulder abduction ROM (Mbefore = 80, Range: 70-100; Mafter = 135, Range: 120-150; p \u3c .05). CONCLUSION: Our research provides evidence for clinical translation in improving health outcomes in middle-aged athletes with a history of proximal humeral fracture union in malposition: shoulder arthroscopy can be simultaneously beneficial in terms of decreasing pain level, increasing ROM, and restoring limb function

    Translation and cross-cultural adaptation methodology for soundscape attributes – A study with independent translation groups from English to Greek

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    The use of questionnaires for soundscape evaluation is a key aspect of soundscape research. Since standards and protocols mainly exist in English, using an appropriate translation and cross-cultural adaptation (CCA) methodology is necessary to maintain content equivalence between source and target language. However, many examples can be found in the literature where no appropriate methodology was applied. This study addresses the neglected aspect of the translation and CCA process in soundscape research by selecting, applying and evaluating an appropriate methodology. After a survey of the relevant literature, an approach based on a combined technique of the forward translation, synthesis, back translation, pre-test and a committee approach was selected. Additional translation guidelines drawn from the literature are suggested and implemented. For the case study of the Greek translation of ISO/TS 12913–2:2018 attributes (Method A), the steps of the methodology were applied by four independent translation groups with different compositions according to the biculturalism and bilingualism of the group members. A method for categorization of bilinguals according to the literature is proposed. In order to compare and validate the results, translated and original attributes were used in listening tests with Greek and English participants respectively, and principal component analysis (PCA) was applied. The most important findings of this research are: the results of the bicultural translation group were closer to the PCA results of the English participants for every attribute, translation of bilingual groups may not be always sufficient, translation errors may be misinterpreted for cross-cultural differences without proper application of a translation methodology and the process of back translation can be effective, especially in cases where there are not corresponding words in the target language. Finally, PCA can be used as a validation methodology for comparison of different translations

    Clinical Management of Congenital Hypogonadotropic Hypogonadism

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    The initiation and maintenance of reproductive capacity in humans is dependent on pulsatile secretion of the hypothalamic hormone GnRH. Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that results from the failure of the normal episodic GnRH secretion, leading to delayed puberty and infertility. CHH can be associated with an absent sense of smell, also termed Kallmann syndrome, or with other anomalies. CHH is characterized by rich genetic heterogeneity, with mutations in >30 genes identified to date acting either alone or in combination. CHH can be challenging to diagnose, particularly in early adolescence where the clinical picture mirrors that of constitutional delay of growth and puberty. Timely diagnosis and treatment will induce puberty, leading to improved sexual, bone, metabolic, and psychological health. In most cases, patients require lifelong treatment, yet a notable portion of male patients (approximate to 10% to 20%) exhibit a spontaneous recovery of their reproductive function. Finally, fertility can be induced with pulsatile GnRH treatment or gonadotropin regimens in most patients. In summary, this review is a comprehensive synthesis of the current literature available regarding the diagnosis, patient management, and genetic foundations of CHH relative to normal reproductive development.Peer reviewe

    Semi-Supervised Deep Learning for Multi-Tissue Segmentation from Multi-Contrast MRI

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    Segmentation of thigh tissues (muscle, fat, inter-muscular adipose tissue (IMAT), bone, and bone marrow) from magnetic resonance imaging (MRI) scans is useful for clinical and research investigations in various conditions such as aging, diabetes mellitus, obesity, metabolic syndrome, and their associated comorbidities. Towards a fully automated, robust, and precise quantification of thigh tissues, herein we designed a novel semi-supervised segmentation algorithm based on deep network architectures. Built upon Tiramisu segmentation engine, our proposed deep networks use variational and specially designed targeted dropouts for faster and robust convergence, and utilize multi-contrast MRI scans as input data. In our experiments, we have used 150 scans from 50 distinct subjects from the Baltimore Longitudinal Study of Aging (BLSA). The proposed system made use of both labeled and unlabeled data with high efficacy for training, and outperformed the current state-of-the-art methods with dice scores of 97.52%, 94.61%, 80.14%, 95.93%, and 96.83% for muscle, fat, IMAT, bone, and bone marrow tissues, respectively. Our results indicate that the proposed system can be useful for clinical research studies where volumetric and distributional tissue quantification is pivotal and labeling is a significant issue. To the best of our knowledge, the proposed system is the first attempt at multi-tissue segmentation using a single end-to-end semi-supervised deep learning framework for multi-contrast thigh MRI scans.Comment: 20 pages, 9 figures, Journal of Signal Processing System

    Interfacility transfers in a non-trauma system setting: an assessment of the Greek reality

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    <p>Abstract</p> <p>Background</p> <p>Quality assessment of any trauma system involves the evaluation of the transferring patterns. This study aims to assess interfacility transfers in the absence of a formal trauma system setting and to estimate the benefits from implementing a more organized structure.</p> <p>Methods</p> <p>The 'Report of the Epidemiology and Management of Trauma in Greece' is a one year project of trauma patient reporting throughout the country. It provided data concerning the patterns of interfacility transfers. We compared the transferred patient group to the non transferred patient group. Information reviewed included patient and injury characteristics, need for an operation, Intensive Care Unit (ICU) admittance and mortality. Analysis employed descriptive statistics and Chi-square test. Interfacility transfers were then assessed according to each health care facility's availability of five requirements; Computed Tomography scanner, ICU, neurosurgeon, orthopedic and vascular surgeon.</p> <p>Results</p> <p>Data on 8,524 patients were analyzed; 86.3% were treated at the same facility, whereas 13.7% were transferred. Transferred patients tended to be younger, male, and more severely injured than non transferred patients. Moreover, they were admitted to ICU more often, had a higher mortality rate but were less operated on compared to non transferred patients. The 34.3% of transfers was from facilities with none of the five requirements, whereas the 12.4% was from those with one requirement. Low level facilities, with up to three requirements transferred 43.2% of their transfer volume to units of equal resources.</p> <p>Conclusion</p> <p>Trauma management in Greece results in a high number of transfers. Patients are frequently transferred between low level facilities. Better coordination could lead to improved outcomes and less cost.</p

    Hydrotherapy (Project Hydriades)

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    Natural resources are being used for the maintenance of health. According to the Law 3498/2006 of the Greek Parliament the natural health spas must be validated for their therapeutic properties. The Association of Municipalities and Communities of Health Springs of Greece signed a contract with the Research Committee of the Aristotle University of Thessaloniki, Greece, in order to conduct the research programme: ‘Study for the documentation of the therapeutic properties of the thermomineral waters’. The main aim of the project is: (1) the study of biological and therapeutic parameters of the natural health sources, (2) the identification of the indications and contraindications of hydrotherapy. Aims parallel to the main ones have been also set
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