Situation models and children’s reading comprehension: what role does visual imagery play?

Individual differences in children’s reading comprehension have been attributed to the level at which a reader is able to construct a coherent meaning-based mental representation of the situation described in a text (i.e., a “situation model”). However, although there is evidence that situation models contain perceptual information such as visual imagery, it is yet to be established whether visual imagery contributes to children’s reading comprehension via its role in situation model construction. To investigate this, three studies were conducted with children in Grades 4 and 5 (age range: 8.08-11.17 years) as part of the current thesis. Study 1 explored the utility of several measures of visual imagery and examined whether this construct is best captured by the differentiation of separate visual imagery processes in this younger population. Fifty-nine children completed five measures of visual imagery, each designed to capture a distinct subcomponent of the visual imagery system, including image generation, image maintenance, image scanning, image transformation, and image strength/vividness. It was found that the visual imagery measures were not highly related to one another and thus each represented a unique construct. However, not all of the included measures proved to be valid and reliable. Utilising the measures of visual imagery that were found to have adequate psychometric properties in Study 1, Study 2 then examined the influence of different subtypes of visual imagery (image maintenance, image scanning and image transformation) on individual differences in reading comprehension. In addition, this study further investigated existing criticisms that traditional measures of reading comprehension do not capture all of the skills involved in situation model construction, by including two separate measures of reading comprehension: a traditional standardised measure (the Neale Analysis of Reading Ability), and a newer measure designed from cognitive theory, which measures higher-level comprehension processes separate to the effects of lower-level reading ability (the Diagnostic Assessment of Reading Comprehension; DARC). It was found that each subtype of visual imagery differentially predicted reading comprehension. In addition, each measure of reading comprehension was differentially influenced by variations in word reading ability and verbal working memory, with evidence that the Neale was more influenced by lower-level reading skills and simple verbal working memory, whereas the DARC was more influenced by non-verbal reasoning and complex verbal working memory. However, visual imagery was not found to be a reliable predictor of reading comprehension; although, this may have been due to an incongruity between the type of imagery that occurs during objective tasks of visual imagery and the visual simulation of narrative events. Thus, Study 3 was designed to disrupt good and poor comprehenders’ visual imagery during reading in order to determine whether good comprehenders show more reliance on visual imagery during comprehension than poor comprehenders. Unexpectedly, however, good comprehenders showed limited evidence of engaging in higher-level comprehension processes (i.e., predictive inferencing) even when imagery was not impaired. Despite this, important implications regarding the use of both textbase and imagery-based representations were revealed, as poor comprehenders displayed increased difficulty maintaining a verbal load during reading compared to a visuospatial load. This suggests that in comparison to good comprehenders, poor comprehenders may have a greater reliance on textbase over imagery-based representations during reading. Overall, this thesis adds to the literature that suggests not all reading comprehension measures are interchangeable in regard s to the underlying skills that they measure. Further, visual imagery may be relevant to reading comprehension; yet, it is likely that this relationship will be further established through careful conceptualisation and measurement of visual imagery versus visual simulation. These findings have implications regarding the use of existing comprehension measures in research and practice, and may also aid future research that investigates the role of visual imagery in higher-level comprehension processes

On the Diophantine equation (nk)=(ml)+d\binom{n}{k}=\binom{m}{l}+d

By finding all integral points on certain elliptic and hyperelliptic curves we completely solve the Diophantine equation $\binom{n}{k}=\binom{m}{l}+d$ for $-3\leq d\leq 3$ and $(k,l)\in\{(2,3),\; (2,4),\;(2,5),\; (2,6),\; (2,8),\; (3,4),\; (3,6),\; (4,6), \; (4,8)\}.$ Moreover, we present some other observations of computational and theoretical nature concerning the title equation

Health Care Management System for Diabetes Mellitus: A Model-based Systems Engineering Framework

The present thesis develops a framework for Health Care Management Systems using modern Model-Based Systems Engineering methodologies and applies it to Diabetes Mellitus. The desired architecture of such systems is described. Tests and interventions, including Health Care IT, used for Diabetes 2 diagnosis and treatment, are described and modeled. A Controlled Markov Chain model for the progression of Diabetes Mellitus with three states, three diagnostic tests, ten interventions, three patient types, is developed. Evaluation metrics for healthcare quality and associated costs are developed. Using these metrics and disease models, two methods for tradeoff analysis between healthcare quality and costs are developed and analyzed. One is an exhaustive Monte Carlo simulation and the other utilizes multi-criteria optimization with full state information. The latter obtains similar results as the former at a fraction of the time. Practical examples illustrate the powerful capabilities of the framework. Future research directions and extensions are described

Tax rulings in the light of the EU State aid rules

Η παρούσα εργασία αποτελείται από δύο πυλώνες, οι οποίοι λειτουργούν αντιθετικά και παράλληλα αλληλοσυμπληρώνονται. Εκκινεί αναλύοντας το φαινόμενο των φορολογικών αποφάσεων/συμφωνιών ''tax rulings'', συμφωνίες που επιδιώκουν πολυεθνικοί όμιλοι επιχειρήσεων, με σκοπό να δώσει μία ολοκληρωμένη εικόνα του περιεχομένου τους, της χρησιμότητάς τους και του τρόπου με τον οποίο αντιμετωπίζονται από τις Φορολογικές Αρχές των κρατών-μελών της Ευρωπαϊκής Ένωσης. Υπό το πρίσμα του φορολογικού ανταγωνισμού που αναπτύσσεται όλο και περισσότερο μεταξύ των κρατών- μελών, αλλά και της φορολογικής πολιτικής που δεν αποτελεί αρμοδιότητα της Ευρωπαϊκής Ένωσης, οι συγκρούσεις των μηχανισμών ενδέχεται να γίνουν πολύπλοκες. Στη συνέχεια, τα tax rulings αναλύονται υπό το δίκαιο των κρατικών ενισχύσεων και αν το τελευταίο αποτελεί εμπόδιο ή λύση στον τρόπο με τον οποίο εφαρμόζονται. Σύγχρονη νομολογία του Δικαστηρίου της Ευρωπαϊκής Ένωσης, αποφάσεις της Ευρωϊκής Επιτροπής και συμπεράσματα κλείνουν τη διπλωματική εργασία, καθώς πλέον ο αναγνώστης έχει τα εφόδια να οδηγηθεί σε πιο ασφαλή πορίσματα και να κρίνει την προσέγγιση των μηχανισμών τόσο της Ε.Ε. όσο και της δημοσιονομικής και φορολογικής πολιτικής που επιδιώκουν να αναπτύσσουν τα κράτη- μέλη στη συνεργασία τους με τους πολυεθνικούς ομίλους.This dissertation consists of two pillars, which function oppositely and at the same time complement each other. It starts by analyzing the phenomenon of tax decisions / agreements "tax rulings", agreements pursued by multinational enterprises in order to give a comprehensive view of their content, their usefulness and how they are treated by the tax authorities of the member states of the European Union. In light of the growing tax competition between member states and the tax policy which is not a conference of the European Union, the conflicts between the mechanisms could become complex. Tax rulings are then analyzed under the state aid law and whether the latter constitutes an obstacle or a solution to the way in which they are applied. Modern case law of the Court of Justice of the European Union, decisions of the European Commission and conclusions are the last part of the thesis, as the reader is now equipped to be led to more secure conclusions and to criticize the approach of the mechanisms of both the E.U., as well as the fiscal and tax policies that member states seek to develop in their cooperation with multinational groups

Synthesis and antimicrobial evaluation of a pyrazoline-pyridine silver(I) complex: DNA-interaction and anti-biofilm activity

The emergence of resistant bacterial strains mainly due to misuse of antibiotics has seriously affected our ability to treat bacterial illness, and the development of new classes of potent antimicrobial agents is desperately needed. In this study, we report the efficient synthesis of a new pyrazoline-pyridine containing ligand L1 which acts as an NN-donor for the formation of a novel silver (I) complex 2. The free ligand did not show antibacterial activity. High potency was exhibited by the complex against three Gram-negative bacteria, namely Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumanii with the minimum inhibitory concentration (MIC) ranging between 4 and 16 μg/mL (4.2–16.7 μM), and excellent activity against the fungi Candida albicans and Cryptococcus neoformans (MIC ≤ 0.25 μg/mL = 0.26 μM). Moreover, no hemolytic activity within the tested concentration range was observed. In addition to the planktonic growth inhibition, the biofilm formation of both Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa was significantly reduced by the complex at MIC concentrations in a dose-dependent manner for Pseudomonas aeruginosa, whereas a biphasic response was obtained for MRSA showing that the sub-MIC doses enhanced biofilm formation before its reduction at higher concentration. Finally, complex 2 exhibited strong DNA binding with a large drop in DNA viscosity indicating the absence of classical intercalation and suggesting the participation of the silver ion in DNA binding which may be related to its antibacterial activity. Taken together, the current results reveal that the pyrazoline-pyridine silver complexes are of high interest as novel antibacterial agents, justifying further in vitro and in vivo investigation

In-depth synthetic, physicochemical and in vitro biological investigation of a new ternary V(IV) antioxidant material based on curcumin.

Curcumin is a natural product with a broad spectrum of beneficial properties relating to pharmaceutical applications, extending from traditional remedies to modern cosmetics. The biological activity of such pigments, however, is limited by their solubility and bioavailability, thereby necessitating new ways of achieving optimal tissue cellular response and efficacy as drugs. Metal ion complexation provides a significant route toward improvement of curcumin stability and biological activity, with vanadium being a representative such metal ion, amply encountered in biological systems and exhibiting exogenous bioactivity through potential pharmaceuticals. Driven by the need to optimally increase curcumin bioavailability and bioactivity through complexation, synthetic efforts were launched to seek out stable species, ultimately leading to the synthesis and isolation of a new ternary V(IV)-curcumin-(2,2’-bipyridine) complex. Physicochemical characterization (elemental analysis, FT-IR, Thermogravimetry (TGA), UV-Visible, NMR, ESI-MS, Fluorescence, X-rays) portrayed the solid-state and solution properties of the ternary complex. Pulsed-EPR spectroscopy, in frozen solutions, suggested the presence of two species, cis- and trans-conformers. Density Functional Theory (DFT) calculations revealed the salient features and energetics of the two conformers, thereby complementing EPR spectroscopy. The well-described profile of the vanadium species led to its in vitro biological investigation involving toxicity, cell metabolism inhibition in S. cerevisiae cultures, Reactive Oxygen Species (ROS)-suppressing capacity, lipid peroxidation, and plasmid DNA degradation. A multitude of bio-assays and methodologies, in comparison to free curcumin, showed that it exhibits its antioxidant potential in a concentration-dependent fashion, thereby formulating a bioreactivity profile supporting development of new efficient vanado-pharmaceuticals, targeting (extra)intra-cellular processes under (patho)physiological conditions

Investigation of the role of bacterial virulence factors and of the protective effect of serrapeptase and curcumin in Alzheimer's disease

Until now, the precise etiology of Alzheimer's Disease (AD) has not been clarified, and effective interventions for its treatment or inhibition have not emerged. Research suggests that the β-amyloid peptide (Aβ) possesses antimicrobial activity, while simultaneously an increased number of bacteria and microbial substances are detected within Aβ plaques in the brains of AD patients. These bacteria persist in a chronic, persistent form of growth within biofilms. Critical factors in biofilm formation, such as amyloids, flagellar proteins (FliC), and lipopolysaccharides (LPSs), can induce neuroinflammation and neurodegeneration like those observed in AD. In this dissertation, elevated levels of LPSs and FliC were found in biological fluids of patients with AD and/or Mild Cognitive Impairment (MCI). LPSs were shown to be useful biomarkers for AD, strongly correlating with signature markers of AD and inflammation, as well as the cognitive status of patients. Furthermore, the inhibitory action of the protease serrapeptase (SPT) against the formation of bacterial membranes by Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was demonstrated. SPT reduced bacterial viability, amyloid levels, and virulence factors such as LPSs and FliC, and affected phosphorus homeostasis by altering the activity of alkaline phosphatases and DING proteins. Finally, the impact of LPSs on mixed cultures of neuroblastoma-glioblastoma and primary neuronal-microglial cells resulted in increased Aβ, the inflammatory enzyme iNOS, cytokines IL-1 and TNF-α, modification of the antioxidant enzyme SOD1 levels, and induction of oxidative stress. Administration of the natural compound curcumin, a vanadium-curcumin complex (V-Cur), or SPT mitigated these effects, with V-Cur exhibiting a stronger therapeutic outcome in some cases. In conclusion, research towards compounds with concurrent anti-inflammatory, anti-amyloidogenic, and antimicrobial properties holds promise for the management of AD.Μέχρι σήμερα η ακριβής αιτιολογία της Νόσου Alzheimer (NA) δεν έχει διασαφηνιστεί, ούτε έχουν προκύψει αποτελεσματικές αγωγές για τη θεραπεία ή την αναστολή της. Έρευνες υποδεικνύουν πως το πεπτίδιο β-αμυλοειδές (Αβ) κατέχει αντιμικροβιακή δράση, ενώ παράλληλα αυξημένος αριθμός βακτηριών και μικροβιακών ουσιών εντοπίζονται εντός των πλακών Αβ σε εγκεφάλους ασθενών. Τα βακτήρια αυτά επενδύουν σε μία χρόνια, επίμονη μορφή ανάπτυξης σε βιομεμβράνες. Κρίσιμοι παράγοντες σχηματισμού της βιομεμβράνης όπως αμυλοειδή, πρωτεΐνες μαστίγιων (FliC) και λιποπολυσακχαρίτες (LPSs) μπορούν να επάγουν νευροφλεγμονή και νευροεκφύλιση παρόμοιες με αυτές στη ΝΑ. Στην παρούσα διατριβή, τα επίπεδα των LPSs και της FliC βρέθηκαν αυξημένα σε βιολογικά υγρά ασθενών με NA ή/και με ΗΝΔ. Δείχτηκε πως οι LPSs μπορούν να αξιοποιηθούν ως βιοδείκτες της ΝΑ, ενώ παράλληλα συσχετίστηκαν ισχυρά με κλασσικούς δείκτες της ΝΑ και της φλεγμονής, αλλά και τη νοητική κατάσταση των ασθενών. Επιπλέον, αποδείχτηκε η ανασταλτική δράση της πρωτεάσης σερραπεπτάση (SPT) έναντι του σχηματισμού βιομεμβράνης από τα βακτήρια Escherichia coli, Pseudomonas aeruginosa και Staphylococcus aureus. Η SPT μειώνει τη βιωσιμότητα των βακτηρίων, τα επίπεδα αμυλοειδών, καθώς και λοιμογόνων παραγόντων όπως οι LPSs και η FliC, ενώ επιδρά και στην ομοιόσταση του φωσφόρου, μεταβάλλοντας τη δραστικότητα των αλκαλικών φωσφατασών και των πρωτεϊνών DING. Τέλος, επίδραση LPSs σε μεικτές καλλιέργειες νευροβλαστώματος-γλοιοβλαστώματος και πρωτογενών νευρικών-μικρογλοιακών κυττάρων οδηγεί σε αύξηση Αβ, του φλεγμονώδους ενζύμου iΝΟS, των κυτταροκινών IL-1 και TNF-α, τροποποίηση των επιπέδων του αντιοξειδωτικού ενζύμου SOD1, καθώς και επαγωγή οξειδωτικής καταπόνησης. Η χορήγηση της φυσικής ουσίας κουρκουμίνη, ενός συμπλόκου βαναδίου-κουρκουμίνης (V-Cur), ή της SPT οδήγησε σε περιορισμό των παραπάνω συνεπειών, με το V-Cur να παρουσιάζει σε περιπτώσεις ισχυρότερο θεραπευτικό αποτέλεσμα. Συμπερασματικά, η αξιοποίηση ουσιών με ταυτόχρονες αντιφλεγμονώδεις, αντι-αμυλοειδικές και αντιμικροβιακές δράσεις, αξίζει να εξεταστεί για τη διαχείριση της ΝΑ

Οι ευρωπαϊκές πολιτικές για την επαγγελματική εκπαίδευση και κατάρτιση και η μεταφορά τους στην Ελλάδα.

Η παρούσα διπλωματική εργασία αντλεί ερευνητικό ενδιαφέρον από την ενσωμάτωση του τομέα της εκπαίδευσης και κατάρτισης στις περιοχές κοινοτικού ενδιαφέροντος αρχής γενομένης με τη συνθήκη του Μάαστριχτ και ακολούθως με τη Στρατηγική της Λισαβόνας και τη Διακήρυξη της Κοπεγχάγης. Συγκεκριμένα, στη νέα οικονομική και κοινωνική πραγματικότητα που διαμορφώνεται ως συνέπεια του φαινομένου της παγκοσμιοποίησης των αγορών και της διασύνδεσή του με το δόγμα του νέο-φιλελευθερισμού η διατήρηση της γνώσης υπό τη μορφή ανανέωσης των ικανοτήτων και επαγγελματικών προσόντων γίνεται αντιληπτή ως μια ατομική και δια βίου διαδικασία. Ως εκ τούτου, τα ευρωπαϊκά συστήματα ΕΕΚ επωμίζονται με τη διαχείριση σημαντικού μέρους των επενδύσεων σε ανθρώπινο κεφάλαιο τόσο σε επίπεδο παραγωγής γνώσης, όσο και διαχείρισης των μαθησιακών διαδρομών στις δομές της δια βίου εκπαίδευσης με αποτέλεσμα την ενίσχυση του διαμεσολαβητικού τους ρόλο στην κατανομή των κοινωνικών και επαγγελματικών θέσεων αλλά και στη διαμόρφωση σημαντικού μέρους του αποθεματικού των «οικονομιών της γνώσης» σε ανθρώπινο δυναμικό. Σε αυτή την ανάγνωση οι μεταρρυθμίσεις που αφορούν στα συστήματα ΕΕΚ και των οποίων τα οφέλη αναμένεται να συμβάλουν σημαντικά στην οικονομική μεγέθυνση της ΕΕ διαμέσου της προώθησης μιας δέσμης των πολιτικών που συγκροτούν τις «Διαδικασίες της Κοπεγχάγης» νομιμοποιούνται με σκοπό την οικοδόμηση ενός ενιαίου ευρωπαϊκού χώρου για την ΕΕΚ, ο οποίος συγκροτείται από πολυεπίπεδα δίκτυα διακυβέρνησης που υπακούουν σε παγκόσμιες εκπαιδευτικές ατζέντες με σκοπό τη μεταφορά των παραγόμενων πολιτικών σε εθνικό επίπεδο διαμέσου της χρήσης τεχνολογιών «εξευρωπαϊσμού» και οριζόντιων πρωτοβουλιών συνεργασίας. Συνεπώς, η διερεύνηση του περιεχομένου των ευρωπαϊκών πολιτικών για την ΕΕΚ, συμπεριλαμβανομένων των εργαλείων και των μηχανισμών προώθησής τους, καθώς και της μεταφοράς τους στο ελληνικό εκπαιδευτικό σύστημα συνιστούν το σκοπό της παρούσας εργασίας. Για την επίτευξη του διττού αυτού σκοπού, στο εφαρμοσμένο πλαίσιο της έρευνας χρησιμοποιήθηκε η Ποιοτική Ανάλυση Περιεχομένου αξιοποιώντας κυρίως πρωτογενείς αλλά και δευτερογενείς πηγές δεδομένων, οι οποίες αποτελούνται από νομοθετικά κείμενα και εκθέσεις της Ευρωπαϊκής Επιτροπής και του Συμβουλίου καθώς επίσης σε μελέτες και επιστημονικά άρθρα με αντίστοιχο περιεχόμενο. Σε επίπεδο συμπερασμάτων επιβεβαιώνεται ο ρόλος της γεωγραφικής κινητικότητας στην ενίσχυση των ανισοτήτων προς όφελος των υψηλά εκβιομηχανισμένων οικονομιών μέσω της διαρροής ανθρώπινου κεφαλαίου, ενώ το νέο καθεστώς διακυβέρνησης που διαμορφώνεται για την ΕΕΚ, ωθεί τα συστήματά της σε «ισομορφισμό» με συνέπεια τα αποτελέσματά τους να αντλούν από συγκεκριμένες δεξαμενές «μαθησιακών αποτελεσμάτων» οι οποίες υπόκεινται στους ίδιους περιορισμούς με την αρχιτεκτονική των πολιτικών που καθοδηγούνται από την πίστη στους αριθμούς. Σε ένα τέτοιο καθεστώς διακυβέρνησης νέες ισχυρές ιδέες και αντιλήψεις διαμορφώνονται για την ΕΕΚ, θεμελιώνοντας τη μεταφορά πολιτικής σε μια πολυπλοκότητα διαμέσου της οποίας καλλιεργείται μια δυναμική με αρνητικές επιπτώσεις στην επιτυχία των προωθούμενων μεταρρυθμίσεων που προωθούνται από το ευρωπαϊκό στο εθνικό επίπεδο.The dissertation draws interest upon the integration of education and training to the European Union´s jurisdiction areas since the Maastricht treaty through Lisbon Strategy and finally to Copenhagen Declaration. Specifically, under the new economic and social reality that emerges as a byproduct of the globalization effect and its interconnectivity with the neo-liberal doctrine, the preservation of knowledge perceived as the perpetual renewal of vocational skills and competence is seen as the responsibility of the individual as well as a life-long lasting procedure. Consequently, European VET systems take on the burden of managing a great deal of the investments in human capital concerning knowledge production as well as provision of learning pathways within the life-long education scheme. As a result, the pivotal role of VET systems regarding the formation of a human resources reserve and its allocation to the economies of knowledge is being enhanced. Under such an interpretation, reforms concerning European member-states’ VET systems are being legitimized, and have been expecting benefits since, to be coined on Europe´s economic growth through the establishment of the cluster of policies known as Copenhagen Procedures, ultimately, with the purpose of building an integrated European space for VET. As such, the integrated European space for VET comprises of multi-disciplinary networks of governance that comply with world educational agendas aiming in policy learning via the use of “Europeanization” technologies and initiatives of lateral co-operation. Therefore, the main aim of this paper comprises the investigation of the text content of the European policy documents, including their promotion tools and apparatuses, as well as the policy learning for the Greek educational system. In order for this dual aim to be achieved, Qualitative Content Analysis has been employed using as primary data sources the Communications, Recommendations and Conclusions of the European Commission and Council as well as secondary data sources consisting of studies and journals. Amongst the results that are accounted for, the role of human resources mobility in amplifying the inequalities for the benefit of the highly industrialized economies via the “brain drain” phenomenon is being confirmed. Additionally, the formation of this new regime of VET governance drives its systems towards “isomorphism” and consequently their outcomes suffer the same limitations that the architecture of the European VET policy framework imposes through its adherence to numbers. Under such a VET governance regime new powerful ideas and perceptions arise, grounding policy learning on a basis of policy dynamics that bring about negative implications for the success of the attempted reforms from the EU to member-state level