37 research outputs found

    CONTRIBUTION OF EMPIRICAL METHODS AND SATELLITE DATA USE FOR ESTIMATING DAILY REFERENCE EVAPOTRANSPIRATION

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    Στην παρούσα εργασία χρησιμοποιούνται επίγεια και δορυφορικά μετεωρολογικά δεδομένα του έτους 2014 από την περιοχή της Βοιωτίας. Τα επίγεια δεδομένα προέρχονται από τον αυτόματο αγρομετεωρολογικό σταθμό (ΑΑΣ) μέτρησης της εξατμισοδιαπνοής αναφοράς (ΕΤο) του Γεωπονικού Πανεπιστημίου Αθηνών (ΓΠΑ). Τα μετεωρολογικά δορυφορικά δεδομένα (SAT) αντιστοιχούν σε πολύγωνο 0.25οΧ0.25ο εντός του οποίου λειτουργεί και ο ΑΑΣ. Χρησιμοποιώντας τα επίγεια αλλά και τα δορυφορικά δεδομένα, υπολογίσθηκε η ΕΤο με τη μέθοδο FAO-56 PM, αλλά και με τρεις εμπειρικές μεθόδους (Copais, Valiantzas και Hargreaves-Samani) και πραγματοποιήθηκαν συγκρίσεις με σκοπό να αξιολογηθεί η αξιοπιστία των μοντέλων. Ως βάση των συγκρίσεων υιοθετήθηκε η μέθοδος FAO-56 PM με χρήση επίγειων δεδομένων. Από την εργασία προκύπτει ότι τόσο για τα επίγεια όσο και για τα δορυφορικά δεδομένα η μέθοδος Copais δίνει τις καλύτερες εκτιμήσεις ακολουθούμενη από την μέθοδο Valiantzas και με σοβαρή υπερεκτίμηση η Hargreaves-Samani. In the present study we used ground and satellite meteorological data of the year 2014 from the region of Viotia-Greece. The ground data were obtained from the automatic grass reference evapotranspiration station (AAS) of the Agricultural University of Athens. The satellite data (SAT) cover an area of 0,25ο x 0,25ο that includes the AAS. By using the ground and the satellite data we calculated the reference evapotranspiration, ΕΤο, with the method FAO-56 PM and with three empirical methods (Copais, Valiantzas and Hargreaves-Samani). The FAO-56 PM was used as a benchmark method to compare and validate the performances of the others methods. The results show that for both the ground and the satellite data, Copais method is the most accurate followed by Valiantzas and Hargreaves-Samani, indicated by serious overestimation

    Predictive model of biliocystic communication in liver hydatid cysts using classification and regression tree analysis

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    <p>Abstract</p> <p>Background</p> <p>Incidence of liver hydatid cyst (LHC) rupture ranged 15%-40% of all cases and most of them concern the bile duct tree. Patients with biliocystic communication (BCC) had specific clinic and therapeutic aspect. The purpose of this study was to determine witch patients with LHC may develop BCC using classification and regression tree (CART) analysis</p> <p>Methods</p> <p>A retrospective study of 672 patients with liver hydatid cyst treated at the surgery department "A" at Ibn Sina University Hospital, Rabat Morocco. Four-teen risk factors for BCC occurrence were entered into CART analysis to build an algorithm that can predict at the best way the occurrence of BCC.</p> <p>Results</p> <p><b>I</b>ncidence of BCC was 24.5%. Subgroups with high risk were patients with jaundice and thick pericyst risk at 73.2% and patients with thick pericyst, with no jaundice 36.5 years and younger with no past history of LHC risk at 40.5%. Our developed CART model has sensitivity at 39.6%, specificity at 93.3%, positive predictive value at 65.6%, a negative predictive value at 82.6% and accuracy of good classification at 80.1%. Discriminating ability of the model was good 82%.</p> <p>Conclusion</p> <p>we developed a simple classification tool to identify LHC patients with high risk BCC during a routine clinic visit (only on clinical history and examination followed by an ultrasonography). Predictive factors were based on pericyst aspect, jaundice, age, past history of liver hydatidosis and morphological Gharbi cyst aspect. We think that this classification can be useful with efficacy to direct patients at appropriated medical struct's.</p

    Cell cyclins: triggering elements of cancer or not?

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    Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy

    Gastrointestinal stromal tumor

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    <p>Abstract</p> <p>Background</p> <p>GISTs are a subset of mesenchymal tumors and represent the most common mesenchymal neoplasms of GI tract. However, GIST is a recently recognized tumor entity and the literature on these stromal tumors has rapidly expanded.</p> <p>Methods</p> <p>An extensive review of the literature was carried out in both online medical journals and through Athens University Medical library. An extensive literature search for papers published up to 2009 was performed, using as key words, GIST, Cajal's cells, treatment, Imatinib, KIT, review of each study were conducted, and data were abstracted.</p> <p>Results</p> <p>GIST has recently been suggested that is originated from the multipotential mesenchymal stem cells. It is estimated that the incidence of GIST is approximately 10-20 per million people, per year.</p> <p>Conclusion</p> <p>The clinical presentation of GIST is variable but the most usual symptoms include the presence of a mass or bleeding. Surgical resection of the local disease is the mainstay therapy. However, therapeutic agents, such as Imatinib have now been approved for the treatment of advanced GISTs and others, such as everolimus, rapamycin, heat shock protein 90 and IGF are in trial stage demonstrate promising results for the management of GISTs.</p

    Aortoenteric fistulae: Present-day management

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    An aortoenteric fistula (AEF) is a communication between the aorta and an adjacent loop of the bowel. The three most useful diagnostic modalities for detecting AEF are abdominal computed tomography scan with intravenous contrast, esophagogastroduodenoscopy, and arteriography. The treatment of AEFs has improved in recent years, but despite the multiple surgical techniques reported, many of the patients do not survive or are left debilitated after treatment. Endovascular repair isanefficient and safe method to stabilize patients with life-threatening AEFs. The aim of this study is to provide a comprehensive and synthetic review of the latest advantages on the diagnosis and management of primary and secondary AEF

    Cell cyclins: Triggering elements of cancer or not?

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    Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy. © 2010 Stamatakos et al; licensee BioMed Central Ltd

    Correlation between Ki67 and Breast Cancer Prognosis

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    Background: Ki67 is an immunohistochemical proliferation marker in many types of cancer and has been widely studied among breast cancer patients mostly through retrospective studies. Methods: The MEDLINE/PubMed database was searched for publications with the medical subject heading &apos;Ki 67&apos; and the key words &apos;breast&apos;, &apos;cancer&apos;, and &apos;prognosis&apos;. We restricted our search to articles published until 2012. Results: In this review, we included 78 articles and abstracts that were accessible and available in English. An effort to further explain the role of Ki67 in the prognosis of breast cancer has been made. Conclusions: The debate on the prognostic role of Ki67 in breast cancer is still open, although most of the studies have established a relation between Ki67 and overall and disease-free survival. Further research should be made in order to establish Ki67 as a standard prognostic marker in breast cancer. Copyright © 2013 S. Karger AG, Basel
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