Creation of virtual worlds from 3D models retrieved from content aware networks based on sketch and image queries

The recent emergence of user generated content requires new content creation tools that will be both easy to learn and easy to use. These new tools should enable the user to construct new high-quality content with minimum effort; it is essential to allow existing multimedia content to be reused as building blocks when creating new content. In this work we present a new tool for automatically constructing virtual worlds with minimum user intervention. Users can create these worlds by drawing a simple sketch, or by using interactively segmented 2D objects from larger images. The system receives as a query the sketch or the segmented image, and uses it to find similar 3D models that are stored in a Content Centric Network. The user selects a suitable model from the retrieved models, and the system uses it to automatically construct a virtual 3D world

Serum Amyloid Alpha in Parapneumonic Effusions

Study objectives. To assess serum amyloid alpha (SAA) pleural fluid levels in parapneumonic effusion (PPE) and to investigate SAA diagnostic performance in PPE diagnosis and outcome. Methods. We studied prospectively 57 consecutive patients with PPE (empyema (EMP), complicated (CPE), and uncomplicated parapneumonic effusion (UPE)). SAA, CRP, TNF-α, IL-1β, and IL-6 levels were evaluated in serum and pleural fluid at baseline. Patients were followed for 6-months to detect pleural thickening/loculations. Results. Pleural SAA levels (mg/dL) median(IQR) were significantly higher in CPE compared to UPE (P < 0.04); CRP levels were higher in EMP and CPE compared to UPE (P < 0.01). There was no significant difference between IL-1β, IL-6, TNF-α level in different PPE forms. No significant association between SAA levels and 6-month outcome was found. At 6-months, patients with no evidence of loculations/thickening had significantly higher pleural fluid pH, glucose levels (P = 0.03), lower LDH (P = 0.005), IL-1β levels (P = 0.001) compared to patients who presented pleural loculations/thickening. Conclusions. SAA is increased in complicated PPE, and it might be useful as a biomarker for UPE and CPE diagnosis. SAA levels did not demonstrate considerable diagnostic performance in identifying patients who develop pleural thickening/loculations after a PPE

Circulating Sclerostin responses to acute weight and non weight bearing sport activity in pre adolescent males

Mechanical loading, i.e. physical activity and/or exercise, promotes bone formation during growth. Sclerostin, a glycoprotein, mediates osteocytes' response to mechanical loading by inhibiting the Wnt/lf-catenin pathway thereby inhibiting bone formation.Published versio

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Fabrication and characterization of transparent high efficiency solar cells

Τhis doctoral thesis focuses on the design, fabrication and electrical characterization of large surface area (156 X 156 mm2) semi-transparent mono-crystalline silicon solar cells with high efficiency. The semi-transparency of our large surface area cells was achieved by creating periodic patterns of ellipses on industrially manufactured and high efficient silicon solar cells using a CO2 laser beam. The design of semi-transparent solar cells became in such a way as to achieve uniform transmittance of incident sunlight combined with low production cost. In the fabrication process of our samples we managed to distribute, over the whole surface area of the cell and at precise positions, the two-dimensional periodic pattern of ellipses in order to achieve uniform transmittance of incident sunlight. Secondly, but very important result of that research, is that we effectively minimize breakages of the thin and large surface area cells during the laser cutting of the pattern elements, by invented and constructed a novel two-level metal base. Analysis of the electrical data shows that the efficiencies of our fabricated large area semi-transparent Si solar cells, with transparencies from 2.9% to 5.4%, vary between 13.2% and 14.2%. Most importantly the analysis shows that the efficiency of a semi-transparent cell depends not only on the total surface area of the elements to be removed by laser cutting but also on the total length of their perimeters. In the second part of this doctoral thesis we investigated and defined the optimum conditions for making reliable lead free interconnections, using copper ribbons covered with environmentally friendly soldering alloys, on commercially manufactured Si solar cells. For replacing the traditional eutectic soldering alloy, two different binary eutectic lead free alloys have been used Sn96.5/Ag3.5 and Sn42/Bi58 with melting temperatures 221°C and 139°C respectively. For studying the performance of the Pb-free interconnections different samples from the two alloys were repeatedly exposed in concentrated solar radiation up to 16 Suns (16X) using Fresnel lenses. Analysis of the electrical measurements shows that the lead-free interconnections were fully responded for extracting the high electric currents generated by such cell while simultaneously demonstrated mechanical stability despite the rapid rise of their temperature due to high concentrations.Στην παρούσα Διδακτορική Διατριβή πραγματοποιήθηκε ο σχεδιασμός,η κατασκευή και ο ηλεκτρικός χαρακτηρισμός ημιδιαφανών ηλιακών κυττάρων μονο-κρυσταλλικού πυριτίου μεγάλης επιφάνειας (156 x 156 mm2) και υψηλής απόδοσης. Η διαπερατότητα των ηλιακών κυττάρων επιτεύχθηκε με την κοπή, με δέσμη λέιζερ διοξειδίου του άνθρακα (CO2), περιοδικών πλεγμάτων ελλείψεων επί συμβατικών ηλιακών κυττάρων μονοκρυσταλλικού πυριτίου. O σχεδιασμός των ημιδιαφανών ηλιακών κυττάρων έγινε έτσι ώστε να παρουσιάζουν ομοιόμορφη διαπερατότητα φυσικού φωτός και υψηλή απόδοση σε συνδυασμό με χαμηλή δαπάνη παραγωγής. Στην κατασκευή των δειγμάτων αρχικά καταφέραμε να κατανεμηθούν ομοιόμορφα και σε ακριβείς θέσεις επί της επιφάνειας τα πολυάριθμα και πολύ μικρών διαστάσεων στοιχεία που απαρτίζουν τα περιοδικά πλέγματα των ελλείψεων ώστε να επιτευχθεί ομοιόμορφη διαπερατότητα ηλιακού φωτός. Δεύτερον, αλλά πολύ σημαντικό αποτέλεσμα της συγκεκριμένης έρευνας, είναι ότι μειώθηκε αποτελεσματικά η θραύση τους κατά τη διάρκεια κοπής των στοιχείων των πλεγμάτων με την επινόηση και κατασκευή μιας μεταλλικής βάσης δύο επιπέδων. Από τον ηλεκτρικό χαρακτηρισμό των δειγμάτων προκύπτει ότι τα καλύτερα ημιδιαφανή ηλιακά κύτταρα πυριτίου που κατασκευάστηκαν παρουσιάζουν αποδόσεις από 13.2% μέχρι 14.2% για τιμές διαπερατότητας από 4.6% μέχρι 5.4%. Το σημαντικότερο συμπέρασμα που προέκυψε από την ανάλυσή των πειραματικών αποτελεσμάτων είναι ότι η απόδοση ενός ημιδιαφανούς κυττάρου Si δεν εξαρτάται μόνο από το συνολικό εμβαδόν επιφάνειας των στοιχείων που αφαιρούνται με κοπή laser, αλλά και από το συνολικό μήκος των περιμέτρων τους. Στο δεύτερο μέρος της Διδακτορικής Διατριβής καθορίστηκαν οι ιδανικότερες συνθήκες συγκολλήσεως για την κατασκευή ωμικών συνδέσεων επίπεδων αγωγών χαλκού που επικαλύπτονται από φιλικά προς το περιβάλλον κράματα σε φωτοβολταϊκά στοιχεία μονοκρυσταλλικού πυριτίου. Τα κράματα που μελετήθηκαν για να αντικαταστήσουν την παραδοσιακά χρησιμοποιούμενη ύλη συγκολλήσεως ήταν τα κασσιτέρου-αργύρου Sn96.5Ag3.5 και βισμουθίου-κασσιτέρου Bi58Sn42 με θερμοκρασίες τήξης 221°C και 139°C. Δείγματα με ωμικές συνδέσεις και από τα δύο κράματα δέχτηκαν συγκεντρώσεις ηλιακής ακτινοβολίας έως 16 ήλιους (16Χ) με την χρησιμοποίηση φακών Fresnel. Τα αποτελέσμτα των ηλεκτρικών μετρήσεων έδειξαν ότι οι ωμικές συνδέσεις ανταποκρίθηκαν πλήρως στην διαχείριση υψηλών ρευμάτων ενώ ταυτοχρόνως επέδειξαν μηχανική αντοχή δεδομένης της ραγδαίας αύξησης της θερμοκρασίας τους με την εφαρμογή υψηλών συγκεντρώσεων

Changes in Polyphenols and Anthocyanin Pigments during Ripening of <i>Vitis vinifera</i> cv Maratheftiko: A Two-Year Study

The vineyard of Cyprus is comprised largely of native Vitis vinifera varieties, which are rather underexploited with regard to wine production to date. Although empirical observations concur that several of these varieties may possess a high potential for the production of quality wines, analytical data pertaining to their polyphenolic composition are scarce. This study was undertaken with the aim of providing a detailed picture of the evolution patterns of several important polyphenolic constituents during the last stages of ripening of Maratheftiko, which is one of the major native grape varieties. This study included monitoring of representative simple phenolics, flavonoids and anthocyanin pigments for two consecutive years, 2021 and 2022, to obtain a more integrated portrayal of changes occurring during the critical period prior to harvest. It was revealed that there was a very high difference in the content of almost all polyphenols considered for the harvests in 2021 and 2022. The grapes harvested in 2022 had a much higher content in catechin, but most importantly, the content in total anthocyanins was 3.91-fold higher in 2022 compared to 2021. On the other hand, trans-resveratrol was the only polyphenolic metabolite whose difference was rather marginal. In seeds, the predominant substance was catechin, which displayed pronounced fluctuations during the period examined. It was concluded that the contents of major polyphenolic metabolites in Maratheftiko grapes might exhibit large variations during the period prior to harvest, most possibly reflecting differences in the average temperature and rainfall. Thus, tight monitoring of technologically important constituents, e.g., anthocyanins, is recommended to ensure the harvest of grapes with optimal maturity

Performance Analysis of Storage Systems in Edge Computing Infrastructures

Edge computing constitutes a promising paradigm of managing and processing the massive amounts of data generated by Internet of Things (IoT) devices. Data and computation are moved closer to the client, thus enabling latency- and bandwidth-sensitive applications. However, the distributed and heterogeneous nature of the edge as well as its limited resource capabilities pose several challenges in implementing or choosing an efficient edge-enabled storage system. Therefore, it is imperative for the research community to contribute to the clarification of the purposes and highlight the advantages and disadvantages of various edge-enabled storage systems. This work aspires to contribute toward this direction by presenting a performance analysis of three different storage systems, namely MinIO, BigchainDB, and the IPFS. We selected these three systems as they have been proven to be valid candidates for edge computing infrastructures. In addition, as the three evaluated systems belong to different types of storage, we evaluated a wide range of storage systems, increasing the variability of the results. The performance evaluation is performed using a set of resource utilization and Quality of Service (QoS) metrics. Each storage system is deployed and installed on a Raspberry Pi (small single-board computers), which serves as an edge device, able to optimize the overall efficiency with minimum power and minimum cost. The experimental results revealed that MinIO has the best overall performance regarding query response times, RAM consumption, disk IO time, and transaction rate. The results presented in this paper are intended for researchers in the field of edge computing and database systems

Successive Solvent Extraction of Polyphenols and Flavonoids from <i>Cistus creticus</i> L. Leaves

The aim of this study was to evaluate the efficiency of successive extraction (using solvents of increasing polarity, namely hexane, ethyl acetate, acetone, ethanol, and water) of polyphenols from Cistus creticus L. The results were compared with the ones obtained from a single-solvent extraction (ethanol, water, and 50% ethanol: water). According to the results, each solvent used for extraction had a significant effect on the yield of extracted polyphenols and the antioxidant activity of the extracts. The highest extraction yield for successive extraction was achieved with ethanol (95.33 mg GAE/g), whereas a comparable amount could also be extracted with 50% ethanol: water mixture single-solvent extraction (96.51 mg GAE/g). The ethanolic and aqueous extracts had the highest antioxidant activity as indicated by their lowest IC50 values in the DPPH assay, specifically 350.99 μg/mL for ethanolic extract of successive extraction and 341.18 μg/mL for 50% ethanol: water mixture of single-solvent extraction, followed by the extract produced using acetone. However, the acetone extract contained more flavonoids than the other two extracts up to 28.03 mg QE/g. The results obtained were in line with those for the single-solvent extraction. It is concluded that using a range of solvents in succession is a more efficient way of extracting higher amounts of antioxidant compounds with varying antioxidant activity