STUDIO DI UN SERVIZIO DI TRASPORTO INTERMODALE FRA L'ITALIA E LA GRECIA

In linea con le più recenti azioni di politica dei trasporti della Unione Europea finalizzate alla incentivazione del trasporto intermodale, nel presente studio si sono approfonditi alcuni aspetti ( economici, tecnici) legati alla possibilità di affermazione di un itinerario di trasporto intermodale mare-ferro tra l’Italia e la Grecia, con possibilità di estensione verso i Balcani e la Turchia

Rock-burst occurrence prediction based on optimized naïve bayes models

Rock-burst is a common failure in hard rock related projects in civil and mining construction and therefore, proper classification and prediction of this phenomenon is of interest. This research presents the development of optimized naïve Bayes models, in predicting rock-burst failures in underground projects. The naïve Bayes models were optimized using four weight optimization techniques including forward, backward, particle swarm optimization, and evolutionary. An evolutionary random forest model was developed to identify the most significant input parameters. The maximum tangential stress, elastic energy index, and uniaxial tensile stress were then selected by the feature selection technique (i.e., evolutionary random forest) to develop the optimized naïve Bayes models. The performance of the models was assessed using various criteria as well as a simple ranking system. The results of this research showed that particle swarm optimization was the most effective technique in improving the accuracy of the naïve Bayes model for rock-burst prediction (cumulative ranking = 21), while the backward technique was the worst weight optimization technique (cumulative ranking = 11). All the optimized naïve Bayes models identified the maximum tangential stress as the most significant parameter in predicting rock-burst failures. The results of this research demonstrate that particle swarm optimization technique may improve the accuracy of naïve Bayes algorithms in predicting rock-burst occurrence. © 2013 IEEE

Prediction of surface treatment effects on the tribological performance of tool steels using artificial neural networks

The present paper discussed the development of a reliable and robust artificial neural network (ANN) capable of predicting the tribological performance of three highly alloyed tool steel grades. Experimental results were obtained by performing plane-contact sliding tests under non-lubrication conditions on a pin-on-disk tribometer. The specimens were tested both in untreated state with different hardening levels, and after surface treatment of nitrocarburizing. We concluded that wear maps via ANN modeling were a user-friendly approach for the presentation of wear-related information, since they easily permitted the determination of areas under steady-state wear that were appropriate for use. Furthermore, the achieved optimum ANN model seemed to be a simple and helpful design/educational tool, which could assist both in educational seminars, as well as in the interpretation of the surface treatment effects on the tribological performance of tool steels

Stochastic vulnerability assessment of masonry structures: Concepts, modeling and restoration aspects

A methodology aiming to predict the vulnerability of masonry structures under seismic action is presented herein. Masonry structures, among which many are cultural heritage assets, present high vulnerability under earthquake. Reliable simulations of their response to seismic stresses are exceedingly difficult because of the complexity of the structural system and the anisotropic and brittle behavior of the masonry materials. Furthermore, the majority of the parameters involved in the problem such as the masonry material mechanical characteristics and earthquake loading characteristics have a stochastic-probabilistic nature. Within this framework, a detailed analytical methodological approach for assessing the seismic vulnerability of masonry historical and monumental structures is presented, taking into account the probabilistic nature of the input parameters by means of analytically determining fragility curves. The emerged methodology is presented in detail through application on theoretical and built cultural heritage real masonry structures

Novel fuzzy-based optimization approaches for the prediction of ultimate axial load of circular concrete-filled steel tubes

An accurate estimation of the axial compression capacity of the concrete-filled steel tubular (CFST) column is crucial for ensuring the safety of structures containing them and preventing related failures. In this article, two novel hybrid fuzzy systems (FS) were used to create a new framework for estimating the axial compression capacity of circular CCFST columns. In the hybrid models, differential evolution (DE) and firefly algorithm (FFA) techniques are employed in order to obtain the optimal membership functions of the base FS model. To train the models with the new hybrid techniques, i.e., FS-DE and FS-FFA, a substantial library of 410 experimental tests was compiled from openly available literature sources. The new model\u2019s robustness and accuracy was assessed using a variety of statistical criteria both for model development and for model validation. The novel FS-FFA and FS-DE models were able to improve the prediction capacity of the base model by 9.68% and 6.58%, respectively. Furthermore, the proposed models exhibited considerably improved performance compared to existing design code methodologies. These models can be utilized for solving similar problems in structural engineering and concrete technology with an enhanced level of accuracy

A novel heuristic algorithm for the modeling and risk assessment of the covid-19 pandemic phenomenon

The modeling and risk assessment of a pandemic phenomenon such as COVID-19 is an important and complicated issue in epidemiology, and such an attempt is of great interest for public health decision-making. To this end, in the present study, based on a recent heuristic algorithm proposed by the authors, the time evolution of COVID-19 is investigated for six different countries/states, namely New York, California, USA, Iran, Sweden and UK. The number of COVID-19-related deaths is used to develop the proposed heuristic model as it is believed that the predicted number of daily deaths in each country/state includes information about the quality of the health system in each area, the age distribution of population, geographical and environmental factors as well as other conditions. Based on derived predicted epidemic curves, a new 3D-epidemic surface is proposed to assess the epidemic phenomenon at any time of its evolution. This research highlights the potential of the proposed model as a tool which can assist in the risk assessment of the COVID-19. Mapping its development through 3D-epidemic surface can assist in revealing its dynamic nature as well as differences and similarities among different districts

Genetic prediction of ICU hospitalization and mortality in COVID-19 patients using artificial neural networks

There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease-19 (COVID-19). We aimed to a) identify complement-related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement-related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID-19. Through targeted next-generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH-related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID-19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID-19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID-19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype

Genetic prediction of ICU hospitalization and mortality in COVID-19 patients using artificial neural networks

There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease-19 (COVID-19). We aimed to a) identify complement-related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement-related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID-19. Through targeted next-generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH-related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID-19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID-19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID-19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype.- Pfizer Pharmaceuticals(undefined

Arabin cervical pessary for prevention of preterm birth in cases of twin-to-twin transfusion syndrome treated by fetoscopic LASER coagulation: the PECEP LASER randomised controlled trial

Abstract Background Fetoscopic LASER coagulation of the placental anastomoses has changed the prognosis of twin-twin transfusion syndrome. However, the prematurity rate in this cohort remains very high. To date, strategies proposed to decrease the prematurity rate have shown inconclusive, if not unfavourable results. Methods This is a randomised controlled trial to investigate whether a prophylactic cervical pessary will lower the incidence of preterm delivery in cases of twin-twin transfusion syndrome requiring fetoscopic LASER coagulation. Women eligible for the study will be randomised after surgery and allocated to either pessary or expectant management. The pessary will be left in place until 37 completed weeks or earlier if delivery occurs. The primary outcome is delivery before 32 completed weeks. Secondary outcomes are a composite of adverse neonatal outcome, fetal and neonatal death, maternal complications, preterm rupture of membranes and hospitalisation for threatened preterm labour. 352 women will be included in order to decrease the rate of preterm delivery before 32 weeks’ gestation from 40% to 26% with an alpha-error of 0.05 and 80% power. Discussion The trial aims at clarifying whether the cervical pessary prolongs the pregnancy in cases of twin-twin transfusion syndrome regardless of cervical length at the time of fetoscopy. Trial registration ClinicalTrials.gov Identifier: NCT01334489 . Registered 04 December 2011

Short-term safety of celocentesis for the mother and the fetus

Coelocentesis offers the potential for prenatal diagnosis as early as 6 weeks of gestation. The aim of this study was to examine the short-term safety of coelocentesis.Eligible for the study were pregnant women with single live fetuses at 6-10 weeks of gestation, requesting pregnancy termination for social reasons. At presentation the patients were counseled extensively about the aim of the study and the usefulness of such a method for couples at high risk .The study included three groups of pregnant women: a. 17 women at 6-11 weeks were examined just before suction termination of pregnancy. Maternal blood samples were taken before, as well as 1 and 10 min after coelocentesis for measurement of alfa fetoprotein (AFP). b. The same approach took place in 20 women of similar gestational age and the fetal heart rate was measured immediately before and 1, 5 and 10 min after the procedure. c. The third group consisted of 447 women requesting termination of pregnancy. Then, they were asked if they were willing to undergo coelocentesis and in 108 of those women who agreed, the procedure was performed at the time of the initial ultrasound scan. A second scan to measure fetal crown-rump length and heart rate was carried out just before termination of pregnancy, that was performed 5-30 days later.There was no significant difference between the maternal serum AFP concentrations before coelocentesis (median 7.5 IU) and the values at 1 min (median 8.6 IU) and 10 min (median 7.5 IU) after the procedure. Similar findings we obtained from the measurment of the fetal heart rate. There was no significant difference between fetal heart rate before coelocentesis (mean 160) and the values at 1 min (mean 158), 5 min (mean 160) or 10 min (mean 159) after the procedure. There were no significant differences between the coelocentesis group (108 women) and the control group (339 women) in maternal age, prevalence of primigravidas, cigarette smokers, existence of uterine fibroids, the median fetal crown-rump length or the interval between the initial scan (or coelocentesis) at presentation and the pregnancy termination. At the time of termination, ultrasound examination demonstrated fetal death in five (4,7%) of the coelocentesis group and nine (2,7%) of the controls. In all other cases, there was normal fetal growth with no significant differences between the two groups in terms of fetal crown-rump length.It is concluded that coelocentesis is not associated with significant feto-maternal haemorrhage and does not exert any short term effect on the cardiovascular system of the fetus. The procedure related risk for fetal loss associated with coelocentesis may be approximately 2%. The results of this study supports that coelocentesis seems a safe procedure for first trimester prenatal diagnosis. Five babies were born following coelocentesis and had no obvious abnormalities. Although the short –term risk of miscarriage from the procedure does not seem to be higher that of the other diagnostic intervention techniques, the long-term safety of the method remains to be assessed.H παρακέντηση της εξωεμβρυϊκής κοιλότητας προσφέρει τη δυνατότητα προγεννητικής διάγνωσης από τις 6 εβδομάδες κύησης. Ο σκοπός της μελέτης μας ήταν η εκτίμηση της βραχυπρόθεσμης ασφάλειας της παρακέντησης της κοιλότητας αυτής. Το υλικό της μελέτης αποτέλεσαν 3 oμάδες εγκύων γυναικών με μονήρη κύηση μεταξύ 6 έως 10 εβδομάδων, που προσήλθαν στην Κλινική μας ζητώντας διακοπή της κύησης για κοινωνικούς λόγους. Κατά την πρώτη επίσκεψη έγινε λεπτομερής ενημέρωση για το σκοπό της μελέτης και τη χρησιμότητα της μεθόδου αυτής για ζευγάρια υψηλού κινδύνου. Σε 17 γυναίκες που διένυαν την 6η-11η εβδομάδα κύησης έγινε μέτρηση της α εμβρυϊκής πρωτεΐνης (AFP) στο μητρικό ορό πριν, καθώς και 1 και 10 λεπτά μετά την παρακέντηση εξωεμβρυϊκής κοιλότητας αμέσως πριν τη διακοπή κύησης για την εκτίμηση εμβρυομητρικής μετάγγισης. Η συγκέντρωση της AFP δεν παρουσίασε στατιστικά σημαντική διαφορά κατά τις τρεις λήψεις.Σε άλλες 20 γυναίκες στην ίδια ηλικία κύησης έγινε μέτρηση της εμβρυϊκής καρδιακής συχνότητας πριν, καθώς και 1, 5 και 10 λεπτά μετά την επέμβαση. Η καρδιακή συχνότητα δεν παρουσίασε στατιστικά σημαντική μεταβολή.Την τρίτη ομάδα αποτέλεσαν 447 γυναίκες. 108 από αυτές συμφώνησαν να γίνει παρακέντηση της εξωεμβρυϊκής κοιλότητας κατά την πρώτη επίσκεψη. Οι υπόλοιπες 339 αποτέλεσαν την ομάδα ελέγχου. Διακοπή κύησης έγινε μετά από 5-30 ημέρες. Ένα δεύτερο υπερηχογράφημα έγινε ακριβώς πριν τη διακοπή της κύησης για έλεγχο της ζωτικότητας του εμβρύου, μέτρηση του κεφαλοουριαίου μήκους και της καρδιακής λειτουργίας του εμβρύου. Δεν υπήρχε σημαντική διαφορά μεταξύ των δύο ομάδων σε δημογραφικά χαρακτηριστικά όπως η ηλικία της μητέρας, κάπνισμα, παρουσία ινομυωμάτων, κεφαλοουριαίο μήκος του εμβρύου ή χρονικό διάστημα μεταξύ του πρώτου υπερηχογραφήματος (ή της παρακέντησης εξωεμβρυϊκού χώρου) κατά την πρώτη επίσκεψη και τη διακοπή της κύησης. Πριν από τη διακοπή, η υπερηχογραφική εξέταση έδειξε απουσία καρδιακών παλμών σε πέντε έμβρυα από την ομάδα μελέτης (4,7%) και σε εννέα από την ομάδα ελέγχου (2,7%). Σε όλες τις άλλες περιπτώσεις υπήρχε φυσιολογική εμβρυϊκή ανάπτυξη και μη σημαντική διαφορά στο κεφαλοουριαίο μήκος των εμβρύων των δύο ομάδων.Συμπερασματικά, το ποσοστό εμβρυϊκής απώλειας από την παρακέντηση της εξωεμβρυϊκής κοιλότητας φαίνεται να είναι περίπου 2%, παρόμοιο με αυτό άλλων επεμβατικών τεχνικών. Δεν παρατηρείται εμβρυομητρική μετάγγιση ούτε βραδυκαρδία του εμβρύου. Έτσι λοιπόν παρέχονται ενδείξεις ότι η μέθοδος προσφέρει βραχυπρόθεσμη ασφάλεια. Πέντε νεογνά που γεννήθηκαν μετά από την εφαρμογή της μεθόδου αυτής δεν παρουσίασαν ανωμαλίες. Παρ’όλο που ο αριθμός αυτός είναι πολύ μικρός, πιθανά είναι ενδεικτικός για την ασφάλεια της μεθόδου όσον αφορά ανατομικές βλάβες του εμβρύου