96 research outputs found

    Pathways of the Modified Atlantic Water across the Strait of Sicily

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    The purpose of this study is to study the medium-scale dynamics, as well as the dynamics of the sub-basin scale in the Central Mediterranean, and to elucidate the routes of the Atlantic waters in this region using a high-resolution numerical model of the eddy-resolving simplest equation. The seasonal variability of the two streams of modified Atlantic waters crossing the Sicilian Strait varies considerably. The main stream along the coast of Tunisia, giving rise to the Atlantic Tunisian current, is stronger than the Atlantic Ionian stream (AIP) from autumn to spring. The Atlantic Tunisian current, which, apparently, is present throughout the year, is characterized by high spatial and temporal variability from the simulation results. The high-resolution model is capable of well reproducing the flow and variability of AIP, including such associating characteristic structures as the Advent Benk Vortex, Moltis Channel Cross, Ionian Benc Vortex and the outflow to the northern Ionian Sea

    Characterization of Coolia spp. (Gonyaucales, Dinophyceae) from Southern Tunisia: first record of Coolia malayensis in the Mediterranean Sea.

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    This study provides the first report of the presence of Coolia malayensis in the Mediterranean Sea, co-occurring with C. monotis. Isolated strains from the Gulf of Gabes, Tunisia (South-eastern Mediterranean) were identified by morpho-logical characterization and phylogenetic analysis. Examination by light and scanning electron microscopy revealed no significant morphological differences between the Tunisian isolates and other geographically distant strains of C. monotis and C. malayensis. Phylogenetic trees based on ITS1-5.8S-ITS2 and D1-D3/28S rDNA sequences showed that C. monotis strains clustered with others from the Mediterranean and Atlantic whereas the C. malayensis isolate branched with isolates from the Pacific and the Atlantic, therefore revealing no geographical trend among C. monotis and C. ma-layensis populations. Ultrastructural analyses by transmission electron microscopy revealed the presence of numerous vesicles containing spirally coiled fibers in both C. malayensis and C. monotis cells, which we speculate to be involved in mucus production

    Selection-free predictions in global games with endogenous information and multiple equilibria

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    Global games with endogenous information often exhibit multiple equilibria. In this paper, we show how one can nevertheless identify useful predictions that are robust across all equilibria and that cannot be delivered in the common-knowledge counterparts of these games. Our analysis is conducted within a flexible family of games of regime change, which have been used to model, inter alia, speculative currency attacks, debt crises, and political change. The endogeneity of information originates in the signaling role of policy choices. A novel procedure of iterated elimination of nonequilibrium strategies is used to deliver probabilistic predictions that an outside observer—an econometrician—can form under arbitrary equilibrium selections. The sharpness of these predictions improves as the noise gets smaller, but disappears in the complete-information version of the model

    A cardiac hydatid cyst underlying pulmonary embolism: a case report

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    Hydatid cysts located in the interatrial septum are especially rare but when they occur, they might cause intracavity rupture. We report on a patient with acute pulmonary embolism caused by an isolated, ruptured hydatid cyst on the right side of the interatrial septum. A 16-year-old-boy with an uneventful history was hospitalized for exercise-induced dyspnea and blood expectorations. Multiple and bilateral opacities were visualized on standard chest x-ray. Signs of right-sided hypertrophy were seen on ECG. Imaging findings led to the diagnosis of pulmonary embolism complicating cardiac hydatid cysts. An operation was performed through median sternotomy to remove the cardiac cyst. The pleural cavity was entered through the fifth intercostal space to withdraw lung hydatid cysts. Operative recovery was uneventful and the patient resumed his normal activities 19 months later. Prompt diagnosis and an appropriate surgical treatment prevented a potentially fatal outcome.Key words: Echinococcosis, Hydatidosis, Pulmonary embolism, cardiac, hydatid cys

    Confluence of CHR Revisited:Invariants and Modulo Equivalence

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    Abstract simulation of one transition system by another is introduced as a means to simulate a potentially infinite class of similar transition sequences within a single transition sequence. This is useful for proving confluence under invariants of a given system, as it may reduce the number of proof cases to consider from infinity to a finite number. The classical confluence results for Constraint Handling Rules (CHR) can be explained in this way, using CHR as a simulation of itself. Using an abstract simulation based on a ground representation, we extend these results to include confluence under invariant and modulo equivalence, which have not been done in a satisfactory way before.Comment: Pre-proceedings paper presented at the 28th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2018), Frankfurt am Main, Germany, 4-6 September 2018 (arXiv:1808.03326

    Confluence Modulo Equivalence in Constraint Handling Rules

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    Previous results on proving confluence for Constraint Handling Rules are extended in two ways in order to allow a larger and more realistic class of CHR programs to be considered confluent. Firstly, we introduce the relaxed notion of confluence modulo equivalence into the context of CHR: while confluence for a terminating program means that all alternative derivations for a query lead to the exact same final state, confluence modulo equivalence only requires the final states to be equivalent with respect to an equivalence relation tailored for the given program. Secondly, we allow non-logical built-in predicates such as var/1 and incomplete ones such as is/2, that are ignored in previous work on confluence. To this end, a new operational semantics for CHR is developed which includes such predicates. In addition, this semantics differs from earlier approaches by its simplicity without loss of generality, and it may also be recommended for future studies of CHR. For the purely logical subset of CHR, proofs can be expressed in first-order logic, that we show is not sufficient in the present case. We have introduced a formal meta-language that allows reasoning about abstract states and derivations with meta-level restrictions that reflect the non-logical and incomplete predicates. This language represents subproofs as diagrams, which facilitates a systematic enumeration of proof cases, pointing forward to a mechanical support for such proofs

    Cardiac tamponade and paroxysmal third-degree atrioventricular block revealing a primary cardiac non-Hodgkin large B-cell lymphoma of the right ventricle: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Primary cardiac lymphoma is rare.</p> <p>Case Presentation</p> <p>We report the case of a 64-year-old non-immunodeficient Caucasian man, with cardiac tamponade and paroxysmal third-degree atrioventricular block. Echocardiography revealed the presence of a large pericardial effusion with signs of tamponade and a right ventricular mass was suspected. Scanner investigations clarified the sites, extension and anatomic details of myocardial and pericardial infiltration. Surgical resection was performed due to the rapid impairment of his cardiac function. Analysis of the pericardial fluid and histology confirmed the diagnosis of non-Hodgkin large B-cell lymphoma. He was treated with chemotherapy.</p> <p>Conclusion</p> <p>The prognosis remains poor for this type of tumor due to delays in diagnosis and the importance of the site of disease.</p

    Prognostic DNA methylation markers for sporadic colorectal cancer: a systematic review

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    Background Biomarkers that can predict the prognosis of colorectal cancer (CRC) patients and that can stratify high-risk early stage patients from low-risk early stage patients are urgently needed for better management of CRC. During the last decades, a large variety of prognostic DNA methylation markers has been published in the literature. However, to date, none of these markers are used in clinical practice. Methods To obtain an overview of the number of published prognostic methylation markers for CRC, the number of markers that was validated independently, and the current level of evidence (LoE), we conducted a systematic review of PubMed, EMBASE, and MEDLINE. In addition, we scored studies based on the REMARK guidelines that were established in order to attain more transparency and complete reporting of prognostic biomarker studies. Eighty-three studies reporting on 123 methylation markers fulfilled the study entry criteria and were scored according to REMARK. Results Sixty-three studies investigated single methylation markers, whereas 20 studies reported combinations of methylation markers. We observed substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology. The median (range) REMARK score for the studies was 10.7 points (4.5 to 17.5) out of a maximum of 20 possible points. The median REMARK score was lower in studies, which reported a p value below 0.05 versus those, which did not (p = 0.005). A borderline statistically significant association was observed between the reported p value of the survival analysis and the size of the study population (p = 0.051). Only 23 out of 123 markers (17%) were investigated in two or more study series. For 12 markers, and two multimarker panels, consistent results were reported in two or more study series. For four markers, the current LoE is level II, for all other markers, the LoE is lower. Conclusion This systematic review reflects that adequate reporting according to REMARK and validation of prognostic methylation markers is absent in the majority of CRC methylation marker studies. However, this systematic review provides a comprehensive overview of published prognostic methylation markers for CRC and highlights the most promising markers that have been published in the last two decades
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