Simulation applied to Evaluate and Improve the Operation of a Soccer Ticket Club Call Centre

Today, call centres are complex systems, consisting of various technological appliances, employing different skilled agents and often spreading on a multi-site worldwide environment. Simulation seems to be the appropriate technique to analyze and optimize such complex systems and has been applied to several cases. This paper examines the appropriateness of the simulation method on a case study where the modelling objectives are derived by the simulation outcomes. It facilitates the “interaction” between the researcher and the model, a process which can enhance the whole study and lead to useful conclusions. Furthermore, the presented simulation models incorporate a combination of aspects including a variable input schedule, multiple services, retrials, call routing, a complex resource allocation policy and queue abandonment phenomena. The methodology followed in the case study includes the assessment of the initial operation of a call centre and the evaluation of improvement scenarios. As shown in this paper, simulation can be applied on different phases of a call centre’s operation such as the evaluation of its performance, the improvement of its operation and the support of day to day activities

Non-native fish species in the North Aegean Sea: a review of their distributions integrating unpublished fisheries data

Fisheries-dependent data and information gathered through fisheries-related scientific surveys can significantly contribute to research on the patterns and processes underlying marine biological invasions and their interactions with fisheries. This study presents an overview of the presence of non-native fish species in the North Aegean Sea, offering insights into their distributions and impact on fisheries. The findings are based on a comprehensive compilation of commercial fisheries-dependent and scientific survey data collected in Greece from 2016 to 2023, along with a systematic review of the international scientific literature. The study resulted in the documentation of the presence of 37 non-native fish species, including several recorded for the first time in the area. The results suggest that non-native fish species invasions in the North Aegean Sea are dynamic. Although most species were classified as casual, and the frequencies of occurrence as well as the quantities in commercial fisheries catches of established species are smaller than in the South Aegean Sea, species introductions and the extent of occurrence and area of occupancy of several species have been increasing since the 2000s. The significance of non-native fish species is becoming increasingly relevant to commercial fisheries in the study area. This is particularly evident in the Northeastern Aegean Sea, where catches of non-native species are on the rise, and new species with potential commercial value have emerged in recent years

Symptomatic intracranial abscess after treating lower cervical spine fracture with halo vest: a case report and review of literature

We present the case of a nineteen year old male, who sustained a fracture of anterior-superior surface of C7, combined with anterior subluxation at the level of C6–C7 vertebrae. After x-ray and CT examination, he was treated conservatively by a Halo-vest. After mobilization, the patient was discharged from the hospital with instructions to visit the outpatient's clinic at regular bases

Specific myeloid signatures in peripheral blood differentiate active and rare clinical phenotypes of multiple sclerosis

Current understanding of Multiple Sclerosis (MS) pathophysiology implicates perturbations in adaptive cellular immune responses, predominantly T cells, in Relapsing-Remitting forms (RRMS). Nevertheless, from a clinical perspective MS is a heterogeneous disease reflecting the heterogeneity of involved biological systems. This complexity requires advanced analysis tools at the single-cell level to discover biomarkers for better patient-group stratification. We designed a novel 44-parameter mass cytometry panel to interrogate predominantly the role of effector and regulatory subpopulations of peripheral blood myeloid subsets along with B and T-cells (excluding granulocytes) in MS, assessing three different patient cohorts: RRMS, PPMS (Primary Progressive) and Tumefactive MS patients (TMS) (n=10, 8, 14 respectively). We further subgrouped our cohort into inactive or active disease stages to capture the early underlying events in disease pathophysiology. Peripheral blood analysis showed that TMS cases belonged to the spectrum of RRMS, whereas PPMS cases displayed different features. In particular, TMS patients during a relapse stage were characterized by a specific subset of CD11c+CD14+ CD33+, CD192+, CD172+-myeloid cells with an alternative phenotype of monocyte-derived macrophages (high arginase-1, CD38, HLA-DR-low and endogenous TNF-a production). Moreover, TMS patients in relapse displayed a selective CD4 T-cell lymphopenia of cells with a Th2-like polarised phenotype. PPMS patients did not display substantial differences from healthy controls, apart from a trend toward higher expansion of NK cell subsets. Importantly, we found that myeloid cell populations are reshaped under effective disease-modifying therapy predominantly with glatiramer acetate and to a lesser extent with anti-CD20, suggesting that the identified cell signature represents a specific therapeutic target in TMS. The expanded myeloid signature in TMS patients was also confirmed by flow cytometry. Serum neurofilament light-chain levels confirmed the correlation of this myeloid cell signature with indices of axonal injury. More in-depth analysis of myeloid subsets revealed an increase of a subset of highly cytolytic and terminally differentiated NK cells in PPMS patients with leptomeningeal enhancement (active-PPMS), compared to those without (inactive-PPMS). We have identified previously uncharacterized subsets of circulating myeloid cells and shown them to correlate with distinct disease forms of MS as well as with specific disease states (relapse/remission)

Simulation applied to Evaluate and Improve the Operation of a Soccer Ticket Club Call Centre

Today, call centres are complex systems, consisting of various technological appliances, employing different skilled agents and often spreading on a multi-site worldwide environment. Simulation seems to be the appropriate technique to analyze and optimize such complex systems and has been applied to several cases. This paper examines the appropriateness of the simulation method on a case study where the modelling objectives are derived by the simulation outcomes. It facilitates the “interaction” between the researcher and the model, a process which can enhance the whole study and lead to useful conclusions. Furthermore, the presented simulation models incorporate a combination of aspects including a variable input schedule, multiple services, retrials, call routing, a complex resource allocation policy and queue abandonment phenomena. The methodology followed in the case study includes the assessment of the initial operation of a call centre and the evaluation of improvement scenarios. As shown in this paper, simulation can be applied on different phases of  a call centre’s operation such as the evaluation of its performance, the improvement of its operation and the support of day to day activities. Aujourd'hui, les centres d'appels sont des systèmes complexes, mettant en oeuvre différentes technologies,nécessitant des qualifications variées et souvent localisés sur plusieurs sites à l'échelle mondiale. La simulation semble être la technique appropriée pour analyser et optimiser de tels systèmes complexes et a été appliquée dans de nombreuses situations. Cet article examine l'adéquation d'une approche par simulation dans le cadre d'une étude de cas où les objectifs de modélisation sont déduits des résultats de simulation. La simulation facilite l'interaction entre le chercheur et le modèle; ce qui peut améliorer l'étude et mener à des conclusions utiles. En outre, les modèles de simulation présentés contiennent une grande variétés d'aspects incluant un calendrier d'entrées, des services multiples, des possibilités d'itérations, l'acheminement d'appels, une politique d'allocation complexes de ressources et des phénomènes d'abandon de file d'attente. La méthodologie suivie dans l'étude de cas inclut non seulement l'évaluation de l'opération initiale d'un centre d'appels mais aussi celles envisagées dans des scénarios d'amélioration. Cet article montre que la simulation peut être appliquée à différentes phases des opérations dans un centre d'appels comme l'évaluation de ses performance, l'amélioration de son management et le soutien aux activités routinières.&nbsp

Methodologies for the processing of measured manire diesel engine gaseous emissions and derivation of values according to MARPOL 73/78 ANNEX VI

129 σ.Στόχος της εργασίας αυτής είναι η ανάπτυξη και αξιολόγηση απλοποιημένων μεθοδολογιών για την εκτίμηση εκπομπών ρύπων από ναυτικούς κινητήρες diesel, με έμφαση στις εκπομπές οξειδίων του αζώτου. Το θέμα που μελετάται και αναλύεται στην παρούσα εργασία, επιλέχθηκε λόγω των όλο και αυστηρότερων κανονισμών που επιβάλλονται για τις εκπομπές ρύπων στη ναυτιλία από τον Διεθνή Ναυτιλιακό Οργανισμό, μέσω της συνθήκης MARPOL 73/78, αλλά και από άλλους εθνικούς οργανισμούς και από την γενικότερη σύγχρονη τάση για φιλικότερες προς το περιβάλλον τεχνολογικές λύσεις στη ναυτιλία. Στην παρούσα διπλωματική αναπτύσσεται μεθοδολογία εκτίμησης ειδικών εκπομπών ρύπων χρησιμοποιώντας μετρημένες συγκεντρώσεις, βασιζόμενη στον Τεχνικό Κώδικά ΝΟx 2008 του Διεθνούς Ναυτιλιακού και μεθοδολογία εκτίμησης ειδικών εκπομπών ρύπων χρησιμοποιώντας μετρημένες συγκεντρώσεις που βασίζεται στη χημεία της στοιχειομετρικής και πραγματικής καύσης.Επιπλέον, γίνεται εφαρμογή των δύο μεθοδολογιών σε μετρήσεις από πέντε ναυτικούς κινητήρες diesel και αξιολογούνται τα αποτελέσματα που προκύπτουν. Τέλος, μελετήθηκε η επίπτωση σφάλματος στις μετρημένες συγκεντρώσεις, στην εκτίμηση της παροχής καυσαερίου και των ειδικών εκπομπών οξειδίων του αζώτου όπως υπολογίζονται από τις δύο μεθοδολογίες.The main purpose of this diploma thesis is the development and evaluation of methodologies for the processing of measured marine diesel engine gaseous emissions and derivation of values, emphasizing on nitrogen oxide (NOx) emissions. The subject of this thesis was chosen due to the stricter and stricter regulations which the International Maritime Organisation (IMO), through the Protocol of 1997 (MARPOL 73/78 Annex VI), and other national organisations imply and the general recent growing tendency over environmentally friendly technological solutions for maritime applications. IMO NOx Technical Code contains an algorithm for the calculation of specific NOx emissions by marine diesel engines. This consists of formulas for the estimation of exhaust gas flow, dry to wet concentration correction and the contribution factor of ambient air temperature and humidity to the final result. A software, based on that algorithm, has been developed and applied to five marine diesel engines. In order to evaluate the results of this application, another software for the estimation of marine diesel engine specific NOx emissions which uses a stoichiometric combustion model and a formula that calculates the Air-Fuel stoichiometric to Air-Fuel actual ratio in order to estimate the actual exhaust gas flow and an alternative dry to wet correction factor calculation has been developed an applied. Finally, a response analysis to both softwares has been done and present how a possible error in any input variable will affect the final result.Νικόλαος Δ. Ευαγγελόπουλο

Transvaginal Ultrasound in Fertile Patients with Suspected Appendicitis: An Experience Report of Current Practice

Background. Transvaginal ultrasound (TVU) in female patients with acute right lower quadrant (RLQ) abdominal pain is time and infrastructure intensive and not always available. This study aims to evaluate the role of TVU in these patients. Methods. Retrospective analysis identified 224 female patients with RLQ pain and TVU. Results. TVU revealed an underlying pathology in 34 (15%) patients, necessitating a diagnostic laparoscopy in 12 patients. Six patients (2%) had a true gynaecological emergency. The remaining 23 patients did not require surgery. The other 190 patients with RLQ pain had a bland TVU; 127 (67%) were discharged, while 63 patients (33%) received a diagnostic laparoscopy. Conclusion. The incidence of true gynaecological emergencies requiring urgent surgical intervention is very low in our patient cohort. TVU is a helpful tool if performed by a physician who is well trained in TVU

Plasma homocysteine levels in patients with multiple sclerosis in the Greek population

Background: In recent years, there has been increasing interest in the role of plasma homocysteine (Hcy) as a possible risk factor for several diseases of the central nervous system. The aim of this study was to determine the plasma levels of Hcy in a group of multiple sclerosis (MS) patients from a Greek population and the possible correlation with age, disability status, activity or duration of disease, sex, and treatment. Methods: The MS group that was studied consisted of 46 patients and a total of 42 healthy individuals served as a control group. Plasma Hcy levels were determined by means of high-performance liquid chromatography coupled with fluorescence detection, after precolumn derivatization with 4-Fluoro-7-aminosulfonylbenzofurazan (ABD-F). Results: Statistical analysis revealed that, in the MS patients, Hcy levels were not significantly different as compared to those in the controls. Men presented with higher Hcy levels than women in the MS group; however, age, disease subtype, disease duration, relapse rate, and Expanded Disability Status Scale score/Multiple Sclerosis Severity Score did not significantly affect Hcy levels in MS patients. Conclusion: The preliminary data suggest that Hcy levels were not elevated in our sample of Greek MS patients, which does not support previous findings of a significant correlation between elevated serum Hcy levels and MS. Further studies to establish a possible association between MS and Hcy levels in the context of different ethnic groups with different habits are needed

Moyamoya Disease May Mimic Multiple Sclerosis?

Introduction. A wide range of medical conditions may mimic multiple sclerosis. Among them, cerebrovascular diseases, including moyamoya disease, need to be excluded since they share common clinical features and radiographic findings with multiple sclerosis. Case Report. A 44-year-old woman experienced transient numbness of her right sided face and arm and was referred to our unit due to small brain lesions in magnetic resonance imaging, with a possible diagnosis of multiple sclerosis. Neurological examination was unremarkable except for plantar reflexes and jerky deep tendon reflexes. Brain magnetic resonance angiography revealed findings typically seen in moyamoya disease, confirmed with digital subtraction angiography. Antiplatelet therapy started, but few days later, she developed suddenly global aphasia and right hemiparesis (National Institutes of Health Stroke Scale/NIHSS 6). Brain magnetic resonance imaging revealed acute infarct in the distribution of the left middle cerebral artery. At her discharge, she was significantly improved (NIHSS 3). Conclusion. Diagnosis of multiple sclerosis is often challenging. In particular, in young patients with transient neurological symptoms and atypical white matter lesions in magnetic resonance imaging, cerebrovascular disorders such as moyamoya disease should be considered in the differential diagnosis. Detailed clinical and neuroimaging evaluation are mandatory for the correct diagnosis