A multidimensionally consistent version of Hirota's discrete KdV equation

A multidimensionally consistent generalisation of Hirota's discrete KdV equation is proposed, it is a quad equation defined by a polynomial that is quadratic in each variable. Soliton solutions and interpretation of the model as superposition principle are given. It is discussed how an important property of the defining polynomial, a factorisation of discriminants, appears also in the few other known discrete integrable multi-quadratic models.Comment: 11 pages, 2 figure

The Self-Concept and Career Aspirations of Greek Students in Greece, France, Germany and Egypt: An Exploratory Study

This study sought to investigate the self-concept and career aspirations held by eleventh grade Greek children who were living in France, Germany and Egypt; the attitudes of these children were compared with those held by their counterparts living on the mainland of Greece. No statistical significance was found on self-concept scores among students living on the mainland of Greece and those living in France and Egypt; statistical significance was found, however, among students who lived in Greece and France and their counterparts living in Germany. The level of career aspiration was shown to be relatively high among all groups involved in the study. No statistical significance relation was found between the degree of self-concept and choice of a profession. The 'ethnic minority' factor, by itself, had no negative effects on self-concept of our selected groups. The main determinant of a child's self-concept seems to be his/her immediate family environment. © 1990, Sage Publications. All rights reserved

Apocrine and eccrine hidrocystomas: A clinicopathological study

Introduction: Eccrine and apocrine hidrocystomas are uncommon, benign, cystic proliferations of the sweat glands usually located on the head and neck area. Objectives: To describe the key clinical and histopathological characteristics of a large series of hidrocystomas in Greece to improve diagnostic accuracy, and to perform a historical review of the medical term hidrocystoma. Methods: A case series of 22 hidrocystomas from 20 consecutive patients treated with surgery at University Hospital of Heraklion in Crete, Greece, from January 1, 1998 to January 1, 2020 was performed along with a comprehensive historical literature review of the term hidrocystoma and its corresponding term hydatis from ancient Greek literature to the present. Data were obtained from medical records. All patients had a histopathologically confirmed diagnosis of hidrocystoma. Formalin-fixed paraffin-embedded (FFPE) sections of 22 tumors of the 20 consecutive patients were retrieved from the pathology laboratory archive and stained for SMA, p63, and GCDFP-15 with immunochemistry and periodic acid-Schiff (PAS) histochemical stain. Results: Overall, 22 hidrocystomas (11 apocrine and 11 eccrine hidrocystomas) surgically excised from 20 patients were included in this study. Of the 20 patients, 10 (50%) were male and 10 (50%) were female, with a mean age of 56 ± 15 years. Hidrocystomas commonly occurred on the eyelids (73%), inner canthus (9%), eyebrow (4.5%), neck (4.5%), nose (4.5%), and ear (4.5%). All apocrine hidrocystomas stained positive for SMA, GCDFP-15, CAM 5.2, PAS, and PAS-D. No recurrence was observed. Conclusions: Here we have presented the clinicopathological characteristics of the largest case series of hidrocystomas in Europe and the Mediterranean region. Only apocrine hidrocystomas stained positive for SMA, GCDFP-15, CAM 5.2, PAS, and PAS-D. © 2021, Slovene Medical Society. All rights reserved

Three-dimensional discrete element modelling of rubble masonry structures from dense point clouds

This paper presents a framework for the three-dimensional structural analysis of full scale, geometrically complex rubble masonry structures from point clouds generated from Structure-from-Motion photogrammetry or terrestrial laser scanning. According to the method, a point-based voxelization algorithm was adopted, whereby a dense point cloud was down-sampled into equidistant points, bypassing the need for conventional intensive processes, such as watertight mesh conversion, to obtain the geometric model of the rubble masonry for structural analysis. The geometry of the rubble masonry structure was represented by a sum of hexahedral rigid blocks (voxels). The proposed “point cloud to structural analysis” framework was implemented to assess the structural stability of the southwest leaning tower of Caerphilly Castle in Wales, UK. Simulations were performed with the three- dimensional computational software 3DEC, based on the Discrete Element Method (DEM) of analysis. Each voxel of the rubble masonry was represented as a rigid, distinct block while mortar joints were modelled as zero thickness interfaces which can open and close depending on the magnitude and direction of the stresses applied to them. The potential of the automated procedure herein proposed has been demonstrated to quantitatively assess the three-dimensional mechanical behaviour rubble masonry structures and provide valuable information to asset owners in relation to the structural health condition of assets in their care