Activist videos: montage as a creative tool for student reflections on their role as spectators

Abstract This article is a reflective text by an art curator interested in exploring the boundaries between video activism, spectatorship, and pedagogy. It proposes new ways of critically understanding the terms "activist," "participation," and "militancy" in the context of an expanded notion of the image and the role of the spectator. Emerging from field notes, the article narrates and shares the experiences of engaging students at workshops for "Between Broadcast – a project around activist videos," held at at fine art academies and universities in Leipzig, Düsseldorf, and Bergamo. The practical aim of the workshops was to introduce and engage students with the subject of so-called activist video clips on YouTube. The students were asked to find, select, and discuss militant videos and, subsequently, to create a montage from them. The conceptual aim of the workshop was to reflect upon video spectatorship online and what that means, the agency of the spectator, and the possibilities of their active participation in the process of viewing. The outcomes of the workshops were the development of critical thinking of the students concerning the subjects of online video, digital empathy, their engagement with videos as individual viewers and as a collective, and the power of montage as a narrative and activist tool

Human and Socioeconomic Rights: A Duty-Based Account

The thesis addresses a question of contemporary philosophical debate: What is the philosophical basis of human and socioeconomic rights? This is an important question given the indeterminacy of rights, and the suspicions regarding their universal validity. What I suggest then is the determination of their philosophical basis. Such a philosophical task would provide the grounds for the clarification of the concept of these rights revealing their true nature, and it would show whether or not these rights are universally valid. Further, through the philosophical justification of human and socioeconomic rights we can explain many of the rights found in the Universal Declaration of Human Rights, as well as in the International Covenant on Civil and Political Rights, and in the International Covenant on Economic, Social, and Cultural Rights. At the same time, through such a justificatory account we can see why some rights are not genuine human rights. Additionally, we can explain why some new rights can be included in the major documents. Finally, such a task brings philosophy at the heart of rights discourse connecting the two disciplines of philosophy and law. Within this context I build my (Kantian) duty-based argument for the justification of human and socioeconomic rights indirectly: 1) by presenting the weaknesses of a number of noteworthy contemporary accounts of how rights are justified, including the justification of them based on the concept of human dignity, and 2) by justifying duties, and then explaining how human and socioeconomic rights can afterwards be generated, or developed, from them. Ultimately, I argue that in our dominant 'rights era', although we should not reject the moral, legal, and political ideas of human and socioeconomic rights, we should put these ideas aside for a while, in order to strengthen the old category of duties, so that eventually both rights and duties could be seen as equal parts in a future account of international justice

ΜΕΛΕΤΗ ΤΗΣ ΕΚΦΡΑΣΗΣ ΜΟΡΙΩΝ mRNA ΚΑΙ microRNA ΣΕ CD138+ ΚΥΤΤΑΡΑ ΑΣΘΕΝΩΝ ΜΕ ΠΛΑΣΜΑΤΟΚΥΤΤΑΡΙΚΕΣ ΔΥΣΚΡΑΣΙΕΣ ΠΟΥ ΘΕΡΑΠΕΥΟΝΤΑΙ ΜΕ ΣΤΟΧΕΥΜΕΝΕΣ ΘΕΡΑΠΕΙΕΣ

Οι πλασματοκυτταρικές δυσκρασίες (PCD) αποτελούν ένα ευρύ φάσμα αιματολογικών παθήσεων που χαρακτηρίζονται από την πλασαματοκυτταρική διήθηση του μυελού των οστών και τη συσσώρευση κυττάρων που παράγουν μονοκλωνικές ανοσοσφαιρίνες. Μερικές απο τις ασθένειες που περιλαμβάνουν είναι το πολλαπλό μυέλωμα (ΜΜ), η μονοκλωνική γαμμαπάθεια απροσδιόριστης σημασίας (MGUS), το «έρπον» μυέλωμα (SMM) και η μακροσφαιριναιμία Waldenström’s. Το πολλαπλό μυέλωμα (ΜΜ) υπολογίζεται πως έχει συχνότητα εμφάνισης 1 έως 2 περιπτώσεις ανά 100.000 άτομα, προσβάλλει κυρίως ηλικιωμένα άτομα, και αντιπροσωπεύει το 1% του συνόλου των νεοπλασιών ενώ για τις αιματολογικές νεοπλασίες αντιπροσωπεύει το 10%. Το πολλαπλό μυέλωμα είναι νεοπλασία των Β-κυττάρων και χαρακτηρίζεται από τον ανεξέλεχτο πολλαπλασιασμό των τελικά διαφοροποιημένων πλασματοκυττάρων στο μυελό των οστών. Τα κακοήθη πλασματοκύτταρα παράγουν μία μονοκλωνική ανοσοσφαιρίνη (Μ-πρωτεΐνη ή παραπρωτεΐνη) και προκαλούν διήθηση του μυελού, οστεολύσεις, αναιμία, νεφρική ανεπάρκεια και ευαισθησία σε μικροβιακές μολύνσεις. Η πρόγνωση και η κλινική πορεία των ασθενών με ΠΜ ποικίλει, με χρόνο επιβίωσης από μερικές ημέρες έως και πάνω από 10 χρόνια. Επιδημιολογικές μελέτες έδειξαν ότι το ΠΜ στο ένα τρίτο των ασθενών προκύπτει από προϋπάρχουσα καλοήθη μονοκλωνική γαμμοπάθεια ενώ στους υπόλοιπους παρουσιάζεται παρακάμπτοντας προϋπάρχουσες καταστάσεις και κάποιες φορές με επιθετική εξέλιξη. Λόγω αυτής της ετερογένειας είναι πολύ πιθανό η παθογένεια και η εξέλιξη της νόσου να καθορίζεται απο γενετικούς μηχανισμούς μέσω διαφορετικών μονοπατιών. Η κατανόηση επομένως των γενετικών αυτών αλλαγών είναι καθοριστικής σημασίας για την πρόγνωση, κλινική παρακολούθηση και θεραπεία των ασθενών με ΠΜ. Ένα ιδιαίτερα γρήγορα αναπτυσσόμενο πεδίο έρευνας για τον καρκίνο είναι η μελέτη των μικρομοριακών RNAs (miRNAs). Τα miRNAs αποτελούν μια μεγάλη οικογένεια μικρών μη κωδικών μορίων RNA, τα οποία ρυθμίζουν βασικές κυτταρικές λειτουργίες. Πρόσφατα δεδομένα παρουσιάζουν τα miRNAs ως πολλά υποσχόμενους καρκινικούς δείκτες. Σκοπός της παρούσας διπλωματικής εργασίας ήταν η ανάλυση της έκφρασης, μέσω ανάπτυξης ευαίσθητων μεθοδολογιών, η μελέτη και η κλινική αξιολόγηση, ορισμένων mRNA μορίων αλλα και μη κωδικών γονιδίων microRNA στο πολλαπλό μυέλωμα ως νέων μοριακών βιοδεικτών για τη διάγνωση και πρόγνωση της νόσου, καθώς και την πρόβλεψη της θεραπευτικής ανταπόκρισης των ασθενών. Τα microRNAs (miRNAs) έχουν μήκος 21−23 νουκλεοτίδια καιρυθμίζουν τη γονιδιακή έκφραση στα ευκαρυωτικά κύτταρα μέσω πρόσδεσης σε μια μη κωδική περιοχή των mRNA-στόχων που ονομάζεται 3’-αμετάφραστη περιοχή (3’-UTR). Με αυτόν το μηχανισμό, τα miRNAs ρυθμίζουν την αυτο-ανανέωση, τη διαφοροποίηση και τη διαίρεση των κυττάρων, μέσω της μετα-μεταγραφικής σίγασης των γονιδίων. Τα miRNAs ρυθμίζουν τη γονιδιακή έκφραση είτε αναστέλλοντας τη μετάφραση, είτε προωθώντας την αποδόμηση συγκεκριμένων μεταγράφων RNAs (mRNAs). Παρά το γεγονός ότι ποσοστό 3% των γονιδίων του ανθρώπου κωδικοποιεί miRNAs, τα εν λόγω miRNAs ρυθμίζουν περίπου το 30% των γονιδίων που κωδικοποιούν πρωτεΐνες. Αυτό υποδεικνύει όχι μόνο τη σημασία τους σε ποικίλα ρυθμιστικά μονοπάτια, αλλά και το δυναμικό τους για χειρισμό των λειτουργιών του κυττάρου. Επιπρόσθετα, όσον αφορά στον καρκίνο, τα miRNAs έχει παρατηρηθεί να δρουν τόσο ως ογκοκατασταλτικά μόρια όσο και ως ογκογονίδια, τα οποία αναστέλλουν και επάγουν-προάγουν την ανάπτυξη όγκου, αντίστοιχα. Επιπλέον, μια συνολική υποέκφραση των miRNAs παρατηρείται σε πολλούς καρκινικούς ιστούς, σε σύγκριση με τους αντίστοιχους φυσιολογικούς. Επομένως, μια δυναμική θεραπευτική χρήση των miRNAs αφορά στη διόρθωση των απορρυθμισμένων επιπέδων μετάφρασης γονιδίων-στόχων που εμπλέκονται σε μονοπάτια σηματοδότησης στα καρκινικά κύτταρα, και ιδιαίτερα στα καρκινικά βλαστοκύτταρα που πρωτίστως ευθύνονται για την καρκινογένεση και τις μεταστάσεις. Πραγματοποιήθηκε συλλογή και επεξεργασία ενός σημαντικού μεγέθους δειγμάτων CD138+ κυττάρων από ασθενείς με μονοκλωνική γαμμαπάθεια αδιευκρύνιστης σημασίας (MGUS), ασυμπτωματκό πολλαπλό μυέλωμα (SMM) και πολλαπλό μυέλωμα (ΜΜ) . Αφού έγινε απομόνωση του ολικού RNA των δειγμάτων, και η σύνθεση του cDNA με την αντίδραση της αντίστροφης μεταγραφής αναλύθηκε η έκφραση mRNA μεταγράφων αρχικά για τα γονίδια αναφοράς GAPDH και HPRT1 καθώς και ορισμένων γονιδίων-στόχων όπως APAF1, BAK1, BID, BIM, BCL2L12, BOK, BAX, BCLX, MCL1, KLK4, KLK5, KLK6, KLK7 και KLK8 σε δείγματα CD138+ κυττάρων , μέσω της ποσοτικής PCR πραγματικού χρόνου (real-time qPCR) αλλά και μέσω της μεθόδου «Nested PCR» για το γονίδιο αναφοράς GAPDH και τα BAX, BCL2, BCL2L12, BCLX, και BOK ώστε να ενισχυθεί η έκφραση αλλά τα αποτελέσματα δεν ήταν ικανοποιητικά. Αυτά τα μη ικανοποιητικά αποτελέσματα μπορεί να οφείλονται στην τεχνική της εκχύλισης του RNA, στην παρουσία αναστολέων και στις διαφορετικές αποδόσεις των αντιδράσεων της αντίστροφης μεταγραφής και PCR μεταξύ των διαφορετικών δειγμάτων ή υπάρχει κάποιο άλλο μόριο όπως η παραπρωτεΐνη Μ οπου η υπερπαραγωγή της να εμποδίζει την μελέτη της έκφρασης των mRNA μεταγράφων των γονιδίων αυτών. Τα miRNAs, ως ογκογονίδια ή καταστολείς όγκων, ρυθμίζουν τις οδούς σηματοδότησης που σχετίζονται με την εξέλιξη του πολλαπλού μυελώματος. Η ανάλυση της έκφρασης των miR-221 και miR-222, πραγματοποιήθηκε με χρήση της ποσοτικής αντίδρασης πραγματικού χρόνου (real-time qPCR) με γονίδιο αναφοράς το RNU48 . Για την ανίχνευση των προϊόντων χρησιμοποιήθηκε η χρωστική SYBR Green I. Η μέθοδος ποσοτικοποίησης που χρησιμοποιήθηκε ηταν 2-ΔΔCt η μέθοδος αυτή ήταν επιτυχής.Η διερεύνηση της κλινικής αξίας των μελετώμενων βιομορίων πραγματοποιήθηκε μέσω εκτενούς βιοστατιστικής ανάλυσης. Πιο συγκεκριμένα, χρησιμοποιήθηκαν κατάλληλες μη παραμετρικές στατιστικές δοκιμασίες για την ανάλυση της κατανομής των επιπέδων έκφρασης των υπό μελέτη γονιδίων σε σχέση με τα κλινικοπαθολογικά χαρακτηριστικά των ασθενών με πολλαπλό μυέλωμα. Για τη διερεύνηση της σχέσης των επιπέδων έκφρασης των miR-221 και miR-222 και των κλινικοπαθολογικών χαρακτηριστικών εφαρμόστηκαν το Mann-Whitney U test και το Jonckheere- Terpstra test . Απο τη διερεύνηση αυτή προέκυψε στατιστικώς σημαντική συσχέτιση του miR-222 με τη διάγνωση, παρατηρήθηκε οτι τα επίπεδα έκφρασης του miR-222 είναι αυξημένα στο έρπων πολλαπλό μυέλωμα σε σχέση με το συμπτωματικό πολλαπλό μυέλωμα και έγινε και απεικόνιση με την καμπύλη ROC. Στη συνέχεια έγινε κατηγοριοποίηση της συνεχούς μεταβλητής των επιπέδων έκφρασης με βάση τη διάμεσο τιμή και διερευνάται επίσης η σχέση των επιπέδων έκφρασης των βιομορίων με τα κλινικοπαθολογικά χαρακτηριστικά εφαρμόζοντας το Chi-Square (χ2 ) τεστ. Το αποτέλεσμα που προέκυψε και ήταν στατιστικά σημαντικό ήταν η συσχέτιση της έκφρασης του miR- 221 με την οστεόλυση. Απο τους ασθενείς που είναι αρνητικοί το 73,9% έχει οστεόλυση και το 26,1% δεν έχει οστεόλυση, ενώ οι ασθενείς οι οποίοι είναι θετικοί το 33,3% έχει οστεόλυση και το 66,7% δεν έχει οστεόλυση με p= 0,013 <0,05. Συμπερασματικά όταν έχουμε χαμηλά επίπεδα έκφρασης του miR-221 αυξάνεται το ποσοστό των ασθενών με οστεόλυση ενώ όταν τα επίπεδα έκφρασης είναι υψηλά μειώνεται το ποσοστό των ασθενών με οστεόλυση.Plasmacellular dyscrasias (PCD) are a wide spectrum of hematological diseases characterized by plasmacellular bone marrow infiltration and the accumulation of monoclonal immunoglobulin-producing cells. Such diseases are multiple myeloma (MM), monoclonal gammapathy of indeterminate importance (MGUS), "SMOLDERING" myeloma (SMM) and Waldenström's macroglobulinemia. Multiple myeloma (MM) is estimated to have an incidence of 1 to 2 cases per 100,000 individuals, predominantly elderly, and represents 1% of all tumors and 10% of hematologic tumors. Multiple myeloma is B-cell neoplasia and is characterized by the uncontrolled proliferation of differentiated plasma cells in the bone marrow. Malignant plasma cells produce a monoclonal immunoglobulin (M-protein or paraprotein) and cause marrow infiltration, osteolysis, anemia, renal failure and susceptibility to microbial infections. The prognosis and clinical course of patients with MM varies, with survival time ranging from a few days to more than 10 years. Epidemiological studies have shown that MM in 1/3 of patients derives from pre-existing benign monoclonal gammopathy, while in the rest is bypassed by pre-existing conditions and sometimes aggressive. Due to this heterogeneity, the pathogenesis and evolution of the disease are very likely to be determined by genetic mechanisms through different pathways. Understanding these genetic changes is therefore crucial for the prognosis, clinical follow-up and treatment of patients with MM. One fast-growing field of cancer research is the study of micro molecular RNAs (miRNAs). miRNAs are a large family of small non-coding RNA molecules that regulate basic cellular functions. Recent data presents miRNAs as promising cancer markers. The purpose of this thesis was the expression analysis, through the development of sensitive methodologies, the study and clinical evaluation of certain mRNA molecules and microRNAs in multiple myeloma as new molecular biomarkers for diagnosis and prognosis of the disease, as well as for patients' therapeutic response prediction. MicroRNAs (miRNAs) are 21-23 nucleotides in length and regulate gene expression in eukaryotic cells by binding to a non-coding region of the target mRNA called the 3'-untranslated region (3'-UTR).By this mechanism, miRNAs regulate self-renewal, differentiation and cell division, through post-transcriptional silencing of genes. miRNAs regulate gene expression either by inhibiting translation or by promoting the degradation of specific RNAs (mRNAs). Although only 3% of human genes encode miRNAs, these miRNAs regulate about 30% of the genes encoding proteins. This indicates not only their importance in a variety of regulatory pathways, but also their potential for manipulating cell functions. In addition, miRNAs have been observed to act both as tumor suppressor molecules and as oncogenes, which inhibit and induce tumor growth, respectively. In addition, a general overexpression of miRNAs is observed in many cancerous tissues, compared to their corresponding normal. Therefore, a dynamic therapeutic use of miRNAs is focused on the downregulation of the expression levels of target genes expression involved in signaling pathways in cancer cells, and in particular in cancer stem cells primarily responsible for carcinogenesis and metastases. A significant size of CD138+ cell samples were collected and processed from patients with unambiguous monoclonal gammapathy (MGUS), asymptotic multiple myeloma (SMM), and multiple myeloma (MM). After isolation of total RNA from the samples, and cDNA synthesis by reverse transcription reaction, the transcript mRNA expression was initially analyzed for the GAPDH and HPRT1 reporter genes as well as certain target genes such as APAF1, BAK1, BID, BIM, BL, BCL, BOK, BAX, BCLX, MCL1, KLK4, KLK5, KLK6, KLK7, KLK7 and KLK8 in CD138+ cell samples, using real-time quantitative PCR (real-time qPCR) as well as the 'Nested PCR' method for the GAPDH reporter gene. and BAX, BCL2, BCL2L12, BCLX, and BOK to enhance expression but the results were not satisfactory. These unsatisfactory results may be due to the technique of RNA extraction, the presence of inhibitors and the different yields of reverse transcription and PCR reactions between the different samples, or due to the presence of another molecule such as paroprotein M, the overproduction of which prevents the expression analysis of these mRNA transcripts of these genes. MiRNAs, as oncogenes or tumor suppressors, regulate signaling pathways associated with the development of multiple myeloma. Expression analysis of miR-221 and miR-222 was performed using real-time qPCR. The expression levels were normalized to RNU48 reporter gene levels. SYBR Green I was used to detect the products. The relative quantification method used was 2-ΔΔCt. This method was successful. The clinical value of the studied biomolecules was investigated through extensive biostatistical analysis. In particular, appropriate nonparametric statistical tests were used to analyze the distribution of the expression levels of the under-study molecules in various clinicopathological characteristics of patients with multiple myeloma. Mann-Whitney U test and Jonckheere-Terpstra test were used to investigate the relationship between miR-221 and miR-222 expression levels and clinicopathological characteristics. This study showed a statistically significant association of miR-222 with the diagnosis, It was observed that expression levels of miR-222 are elevated in smoldering multiple myeloma compared to symptomatic multiple myeloma, and the ROC curve was also plotted. The result, which was statistically significant, was the association of miR-221expression with osteolysis. Of the patients who were negative, 73.9% had osteolysis, while 26.1% did not. In positive patients 33.3% had osteolysis while 66.7% did not (p = 0.013). In conclusion, low expression levels of miR-221 are related to a higher rate of osteolysis, while high expression levels of miR-221 are related to a lower rate of osteolysis

Μελέτη προσομοίωσης ημιαυτοματοποιημένου συστήματος συλλογής και αποθήκευσης προιόντων σε μεγάλο κέντρο διανομής με χρήση λογισμικού FLEXSIM

260 σ.Σκοπός αυτής της εργασίας είναι η μελέτη της νέας ημιαυτοματοποιημένης εγκατάστασης αποθήκευσης της εταιρείας Trade Logistics. Το λογισμικό που χρησιμοποιήθηκε είναι το FlexSim, εκτελεί προσομοίωση διακριτών γεγονότων και ειδικεύεται σε εφαρμογές εφοδιαστικής και παραγωγής. Η εγκατάσταση διαιρέθηκε σε επιμέρους τμήματα βάσει των τριών βασικών δραστηριοτήτων που εκτελεί: αποθήκευση totes, τροφοδοσία totes και picking τεμαχίων από totes. Τα μοντέλα των επιμέρους τμημάτων της εγκατάστασης, αφού επαληθεύτηκαν βάσει των θεωρητικών τιμών που προμήθευσε εταιρεία, σχημάτισαν το συνολικό μοντέλο. Μετά την επαλήθευση εξετάστηκαν σενάρια (χρήση διαφορετικού πλήθους και χαρακτηριστικών χειριστών, διαφορετικών ρυθμών τροφοδοσίας κ.λπ.) και προέκυψε ότι για τις υπάρχουσες ανάγκες της εταιρείας η εγκατάσταση καλύπτει τα ζητούμενα για τις τρέχουσες ανάγκες της. Λέξεις Κλειδιά: Προσομοίωση, Μοντελοποίηση, Εφοδιαστική, DES, FlexSimThe scope of the present thesis is the study of the new semi-automated installation for quick replenishment of Trade Logistics S.A. The software used is a Discrete Event Simulation package, FlexSim, which specializes in logistics and production applications. The installation was divided in sections according to its three basic functions: tote short time storage, totes decanting and item picking from totes. A model was created for each section, and then was validated according to theoretical data provided by the company. All section models were combined to form the total installation model. After the validation different scenarios were examined in partial models (used of different number of operators with different attributes, different rates of tote feeding etc.) and as a result it was evident that the installation is filling company’s expectations for the current time. Kew Words: Simulation, Modeling, Logistics, DES, FlexSimΕΛΕΝΗ ΛΙΟΣ

Cord Blood Ischemia-Modified Albumin Levels in Normal and Intrauterine Growth Restricted Pregnancies

Ischemia-modified albumin (IMA) is a sensitive biomarker of cardiac ischemia. Intrauterine growth restriction (IUGR) may imply fetal hypoxia, resulting in blood flow centralization in favour of vital organs (brain, heart, adrenals—“brain sparing effect”). Based on the latter, we hypothesized that cord blood IMA levels should not differ between IUGR and appropriate-for-gestational-age (AGA) full-term pregnancies. IMA was measured in blood samples from doubly-clamped umbilical cords of 110 AGA and 57 asymmetric IUGR pregnancies. No significant differences in IMA levels were documented between AGA and IUGR groups. IMA levels were elevated in cases of elective cesarean section (P = .035), and offspring of multigravidas (P = .021). In conclusion, “brain sparing effect” is possibly responsible for the lack of differences in cord blood IMA levels at term, between IUGR and AGA groups. Furthermore, higher oxidative stress could account for the elevated IMA levels in cases of elective cesarean section, and offspring of multigravidas

Effects of the pre-irradiation storage procedure on the dose response of a Fricke xylenol orange gel dosimeter

Abstract The Fricke xylenol orange (FX) gel system is a chemical dosimeter characterized by good sensitivity, linear dose response, tissue equivalence, no toxicity, easy preparation, reproducibility and low cost. Thanks to the presence of the gelatinous matrix, the system is particularly suitable to perform reliable 3D mapping of the absorbed dose spatial distribution via magnetic resonance imaging (MRI) or optical techniques. The aim of this work is to study in a systematic way the influence of the pre-irradiation storage procedure upon sensitivity, dose response stability and lifetime of use of a FX gel system made with gelatin from porcine skin subjected to homogeneous irradiation. For this purpose, different pre-irradiation storage procedures, in terms of temperature and duration of each storage step, were investigated. In order to evaluate the dose response stability, the optical analyses of the samples were performed up to 6 hours after irradiation. Moreover, the samples were irradiated at time intervals of 24 hours for up to 7 days after preparation in order to evaluate the system lifetime of use. Regardless of their thermal and temporal life, the samples show linear dose responses in the investigated dose range (3-24 Gy) and an increase of sensitivity with the time elapsed between preparation and irradiation. Among the three pre-irradiation storage procedures considered here, a procedure that provides the best dose response stability and lifetime of use was identified and recommended for further use. The analyzed dosimetric system possesses good properties that make it promising for medical application, particularly concerning the evaluation of pre-treatment plan quality assurance within the conformational external beam radiotherapy</jats:p

Pilot scale validation campaign of gel dosimetry for pre-treatment quality assurance in stereotactic radiotherapy

Purpose: Complex stereotactic radiotherapy treatment plans require prior verification. A gel dosimetry system was developed and tested to serve as a high-resolution 3D dosimeter for Quality Assurance (QA) purposes.Materials and Methods: A modified version of a polyacrylamide polymer gel dosimeter based on chemical response inhibition was employed. Different sample geometries (cuvettes and phantoms) were manufactured for calibration and QA acquisitions. Irradiations were performed with a Varian Trilogy linac, and analyses of irradiated gel dosimeters were performed via MRI with a 1.5 T Philips Achieva at 1 mm3 or 2 mm3 isotropic spatial resolution. To assess reliability of polymer gel data, 54 stereotactic clinical treatment plans were delivered both on dosimetric gel phantoms and on the Delta4 dosimeter. Results from the two devices were evaluated through a global gamma index over a range of acceptance criteria and compared with each other.Results: A quantitative and tunable control of dosimetric gel response sensitivity was achieved through chemical inhibition. An optimized MRI analysis protocol allowed to acquire high resolution phantom dose data in time -frames of approximate to 1 h. Conversion of gel dosimeter data into absorbed dose was achieved through internal calibration. Polymer gel dosimeters (2 mm3 resolution) and Delta4 presented an agreement within 4.8 % and 2.7 % at the 3 %/1 mm and 2 %/2 mm gamma criteria, respectively.Conclusions: Gel dosimeters appear as promising tools for high resolution 3D QA. Added complexity of the gel dosimetry protocol may be justifiable in case of small target volumes and steep dose gradients

One-pot glycerol oxydehydration on multifunctional catalysts: influence of acid and redox properties on the catalytic performance

[EN] We report on a study of the key reaction parameters in glycerol oxidehydration into acrylic acid over W-V-Nb mixed oxides with a hexagonal tungsten bronze structure. This investigation demonstrated that the optimal control of the two consecutive steps of acid-catalysed glycerol dehydration into acrolein and aldehyde oxidation into acrylic acid, and of the parallel reaction of acrolein transformation into by-products (ketals and oligomers), was achieved in the presence of a defined glycerol-to-oxygen inlet ratio. Indeed, oxygen played the fundamental role of accelerating the oxidation of the intermediately formed acrolein into acrylic acid, by allowing a greater concentration of the oxidizing V5+ sites. In fact, an unprecedented higher yield to acrylic acid and acrolein compared to W-V bronzes was registered (maximum acrylic acid yield 50.5%) together with an increase of more than one order of magnitude in productivity, because of both the greater concentration of glycerol used in the inlet feed and the lower contact time needed. Further experiments were carried out by reacting acrolein and methanol in oxidative conditions, the latter as a model molecule for the determination of surface acid and redox properties.CIRI (Centro per la Ricerca Industriale), Università di Bologna, is acknowledged for the grant to A.C.The Valencia group also thanks the financial support of Dirección General de Investigación Científica y Técnica in Spain (Project CTQ2012-37925-C03-01).Chieregato, A.; Soriano Rodríguez, MD.; Basile, F.; Liosi, G.; Zamora Blanco, S.; Concepción Heydorn, P.; Cavani, F.... (2014). One-pot glycerol oxydehydration on multifunctional catalysts: influence of acid and redox properties on the catalytic performance. Applied Catalysis B Environmental. 150-151:37-46. https://doi.org/10.1016/j.apcatb.2013.11.045S3746150-15

Un nuovo processo per la sintesi di acroleina e acido acrilico da glicerolo

La trasformazione di glicerolo ad acido acrilico può essere un fattore importante per la valorizzazione del processo di produzione di biodiesel, il quale prevede la coproduzione di enormi quantità di glicerolo. La sintesi di acido acrilico in un unico step è stata studiata attraverso vari catalizzatori solidi bifunzionali di diversa natura, contenenti proprietà acide e redox. I catalizzatori devono avere un’adeguata acidità di Brønsted per promuovere la trasformazione di glicerolo ad acroleina, mentre le proprietà ossidanti, necessarie per la sintesi di acido acrilico sono ottenute mediante l’inserimento di un metallo ossidante nella struttura. Si vuole quindi sintetizzare e testare una serie di catalizzatori che mostrino questa bifunzionalità in grado di soddisfare requisiti di attività e selettività nei confronti della reazioni . Per questo studio sono stati sintetizzati e caratterizzati ossidi misti di W/V, nella forma di aggregati dispersi sulla titania ed ossidi misti di Zr/Nb/V in struttura bulk. Sono stati quindi eseguiti dei test di reattività in fase gas ed in presenza di ossigeno utilizzando un reattore tubolare in quarzo a letto fisso

Social Networks as Digital Archives: Videos of the Tunisian Revolution Post-January 14, 2011

Questa tesi offre un approfondimento sul ruolo svolto dai social networks, in particolare YouTube e Facebook, in quanto archivi digitali, attraverso l’osservazione del caso empirico dei video vernacolari girati e diffusi durante la fase dei ventinove giorni della rivoluzione tunisina, nel periodo successivo al 14 gennaio 2011. Nel quadro critico della natura commerciale dei social network, esploro le questioni della conservazione e della trasmissione nel tempo di queste testimonianze visive online e offline. A questo proposito, individuo lo spettatore come agente di trasformazione nei video proposti, il quale, utilizzando lo strumento del montaggio cinematografico come modus operandi, può creare nuove narrazioni a partire dai materiali audiovisivi in questione. I risultati della mia ricerca suggeriscono che, laddove la circolazione dei filmati online diminuisce dopo il 14 gennaio 2011, YouTube sembra proporsi come un archivio time-based che può essere utilizzato retrospettivamente dagli utenti/spettatori per recuperare nel tempo i video amatoriali online, e ricombinarli. Questo, grazie specialmente alle caratteristiche infrastrutturali di YouTube, come la ricercabilità e l'iperaccessibilità dei contenuti. Lo spettatore emerge, dunque, come il soggetto in grado di utilizzare i social media come archivi, forzando il funzionamento dell'algoritmo. Inoltre, partendo dai contenuti dei social networks, gli spettatori producono altre forme di archivio online e offline, che veicolano la diffusione dei video nel tempo, ma che al contempo, possono creare gerarchie tra oggetti digitali della stessa natura. Post-14 gennaio 2011, i video si affermano, inoltre, come modelli estetici consolidati di attendibilità. Essi costituiscono, però, anche un'eredità visuale da cui emanciparsi per generare nuove rappresentazioni in grado di raccontare un paese in transizione come la Tunisia. In alternativa, tali materiali audiovisivi vengono attualizzati in altre narrative, che fanno luce sulle attuali controverse questioni politiche e sociali dello stato nordafricano. A questo proposito, la memoria individuale dei video è uno degli ambiti osservati, da cui possono generarsi nuove storie. Oltre ai momenti specifici della fase dei ventinove giorni di rivoluzione che i soggetti intervistati e i partecipanti del focus group ricordano, dalle memorie emerge la percezione di un antagonismo tra le esperienze digitali e quelle fisicamente mediate. Infatti, l'insieme dei fenomeni emotivi legati al processo della memoria mostra dei rapporti individuali controversi con i video della rivoluzione, nel presente. I ricordi emersi mostrano anche il peso ambivalente che tali audiovisivi, in quanto oggetti di memoria connettiva, hanno nella creazione della memoria individuale e collettiva. Il mio materiale illustra, attraverso contraddizioni e limiti, la rilevanza dei social networks come archivi della rivoluzione tunisina, post 14 gennaio 2011. Questo, nonostante la natura commerciale di tali piattaforme. La tesi sottolinea, inoltre, anche il ruolo fondamentale degli spettatori all'interno del processo di archiviazione. Essi sono i soggetti che, in ultima analisi, rendono possibile nel tempo la conservazione dei video attraverso la memoria, la creazione di ulteriori modi di raccontare, e nuove narrazioni relative alla fase dei ventinove giorni della rivoluzione tunisina.This dissertation offers an overview on the role played by social networks, especially YouTube and Facebook, as digital archives. The focus of my research is on the empirical case study of the vernacular videos shot and circulated during the twenty-nine-day phase of the Tunisian revolution, in the post-January 14, 2011 period. I explore questions of the preservation and transmission of these visual testimonies over time in virtual and offline domains within a critical framework of the commercial and highly-capitalistic nature of social networks. In this respect, I point at the spectator as an agent of transformation in the proposed videos by using the tool of cinematic montage as a modus operandi to create new narratives out of the clips. The findings suggest that, whereas the circulation of footage online decreases in post- January 14, 2011, YouTube turns into a time-based archive that can be used retrospectively by users/spectators to retrieve vernacular videos and recombine them, thanks to infrastructural features, such as searchability and the hyperaccessibility of contents. The spectator emerges as the character who performs social media as archives by forcing the functioning of the algorithm. Spectators create other forms of repositories online and offline, which diffuse the clips, while they create hierarchies among digital objects of the same nature. The clips turn into established aesthetic models of trustworthiness. They constitute a legacy from which to liberate in order to create new representations for a country in transition. Alternatively, they enter fictional narratives that shed light on current controversial political and social issues in the country. The exploration of individual memory also produces a set of narratives. Aside from specific scenes, the interviewed subjects and participants of the focus group perceive an antagonism between digital and physically mediated experiences. Indeed, the whole set of emotional phenomena related to the process of recollection shows this controversial relationship with the clips of the revolution in the present time. These recollections also show the ambivalent weight that the so-called connective memory objects have in the creation of individual and collective memory. My material illustrates, through contradictions and limits, the relevance of social networks as repositories of the Tunisian revolution, post-January 14, 2011. This is despite the commercial nature of these internet products. My material also stresses the role of the spectator within the process of archiving as the character that, ultimately over time, makes preservation possible by means of memory and the creation of additional narratives and storytelling of the twenty-nine-day phase of the revolution