Malaria affects millions of people annually especially in third world countries. Increase in resistance and limited research being conducted adds to the global burden of malaria. Mefloquine, known for unwanted adverse reactions and neurotoxicity, is highly lipophilic and is still used as treatment and prophylaxis. Lipid drug delivery systems are commonly used to increase solubility and efficacy and decrease toxicity. The most generally used lipid drug delivery system is liposomes. The lipid bilayer structure varying in size from 25 nm to 100 μm can entrap both hydrophilic and lipophilic compounds. Similar in structure and size to liposomes, Pheroid™ technology consist of natural fatty acids and is also able to entrap lipophilic and hydrophilic compounds. The aim of this study was to formulate liposomes and Pheroid™ vesicles loaded with mefloquine and evaluate the physiochemical characteristic of the formulations followed by efficacy and toxicity studies. Pheroid™ vesicles and liposomes with and without mefloquine were evaluated in size, morphology, pH and entrapment efficacy during three month accelerated stability testing. Optimization of size determination by flow cytometry lead to accurate determination of size for both Pheroid™ vesicles and liposomes. During the three months stability testing, Pheroid™ vesicles showed a small change in size from 3.07 ± 0.01 μm to approximately 3 μm for all three temperatures. Confocal laser scanning microscopic evaluation of the liposomes showed structures uniform in spherical shape and size. No difference in size or structure between the Pheroid™ vesicles with and without mefloquine were obtained. Significant increase (p=0.027) in size from 6.46 ± 0.01 μm to above 10 μm was observed for liposomes at all the temperatures. Clearly formed lipid bilayer structures were observed on micrographs. With the addition of mefloquine to the liposome formulation, a decrease in the amount of bilayer structures and an increase in oil droplets were found. Entrapment efficacy was determined by firstly separating the entrapped drug from the unentrapped drug utilizing a Sephadex®G50 mini column. This was followed by spectrophotometric evaluation by UV-spectrophotometry at 283 nm. Initial entrapment efficacy of both Pheroid™ vesicles and liposomes was above 60%. An increase in entrapment efficacy was observed for Pheroid™ vesicles. The addition of mefloquine to already formulated Pheroid™ vesicles illustrated entrapment efficacy of 60.14 ± 5.59% after 14 days. Formulations loaded with mefloquine resulted in lower pH values as well as a decrease in pH over time. Optimization of efficacy studies utilizing propidium iodide was necessary due to the similarity in size and shape of the drug delivery systems to erythrocytes. A gating strategy was successfully implemented for the determination of the percentage parasitemia. Efficacy testing of mefloquine loaded in Pheroid™ vesicles and liposomes showed a 186% and 207% decrease in parasitemia levels compared to the control of mefloquine. Toxicity studies conducted include haemolysis and ROS (reactive oxygen species) analysis on erythrocytes as well as cell viability on mouse neuroblastoma cells. Pheroid™ vesicles with and without mefloquine resulted in a dose dependent increase in ROS and haemolysis over time. A dose dependent increase in ROS and haemolysis in both liposome formulations were observed, but to a lesser extent. Mefloquine proved to be neurotoxic with similar results obtained when mefloquine was entrapped in liposomes. Pheroid™ vesicles seem to have neuroprotective properties resulting in higher cell viability. Mefloquine could be entrapped successfully in Pheroid™ vesicles and less in liposomes. Pheroid™ vesicles was more stable over a three months accelerated stability testing with more favourable characteristics. The increase in ROS levels of Pheroid™ vesicles could be responsible for the higher efficacy and haemolytic activity. DL-α-Tocopherol in Pheroid™ vesicles possibly acted as a pro-oxidant due to the presence of iron in the erythrocytes. DL-α-Tocopherol showed possible antioxidant properties in the neurotoxicity evaluation resulting in higher cell viability. Even though liposomes illustrated higher efficacy and little haemolysis and ROS production, no difference in neurotoxicity was observed together with unfavourable properties during stability testing makes this drug delivery system less favourable in comparison to Pheroid™ vesicles. Mefloquine was successfully incorporated into Pheroid™ vesicles resulted in high efficacy and showed possible neuroprotection and therefore makes it an ideal system for treatment of malaria. / Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011

Ziel der Arbeit war eine Steigerung der Wasseraufnahme und Harndilution durch Supplementierung von Natriumchlorid (NaCl) oder pH-Wert-Senkung durch Zugabe von Ammoniumchlorid (NH4Cl) zur Reduktion des Harnsteinbildungspotenzials. Durch die NaCl-Zulage wurde die Harnmenge signifikant gesteigert und das spezifische Gewicht des Harns gesenkt. Eine NaCl-Gabe stellt somit einen möglichen ergänzenden therapeutischen Ansatz für eine vermehrte Ausscheidung von Kristallen dar. Eine Ansäuerung des Harns durch Zulage von NH4Cl ließ sich nicht erreichen.

Made available in DSpace on 2016-08-10T10:29:38Z (GMT). No. of bitstreams: 1 LAUDI BARROS DOS SANTOS.pdf: 7657021 bytes, checksum: 82ca2310bc9a3a60421b616fc27991b8 (MD5) Previous issue date: 2009-05-14 / The production of residue has been a focused concern in many debates during the last few decades. The Health Service Residues - RSS is a problem that other than affecting the environment and the health of the professional, it involves other areas such as the basic water plant and the public health. It is important to characterize and analyze the risks associated in the production chain from origin to final destination of the RSS, based on the new management policies of the residues. The reason of the argument about the RSS views making known to the health establishments, the problem in relation to the RSS, identifying the factors in failures, aggravations and risks in the critic, semi-critic and non-critic areas, so that this place accomplishes the expectations of the legislation, as well as incorporating actions to an ideal life quality of the population, of the health professional, through occupational security and environmental preservation. The methods applied in this research is of descriptive nature, by the collection of information, with observation outlines acquired in the Chemotherapy Center - C.Q of the Reference Hospital of Araguaína -HRA of the district of Araguaína/TO, trying to understand through statistic information the relation that it establishes between RSS and the environmental perception. The results acquired in this research demonstrated that the handling rules of these residues are based on in the resolution normalization RDC 306/2004 and the CONAMA 358/2005, understanding the process of segregation, conditioning, identifying, temporarily storing internal and external transporting, and treating, collecting and final destination. Concluding that there s need for applying to the professionals involved in the process, continuous education so that along with an adequate management of the RSS, there will be constant evaluations and routines of these results, with the goal to preserve the health of the employees, professionals, helpers, population and of the environment, ensuring therefore a better quality of life to all society and of the environment. / A produção de resíduos nas últimas décadas tem sido uma preocupação com foco em inúmeras discussões. Os Resíduos de Serviços de Saúde - RSS é um problema que além de afetar o plano ambiental e a saúde do trabalhador, envolve outras áreas como o saneamento básico e a saúde pública. É essencial caracterizar e analisar os riscos associados na cadeia de produção, da origem à destinação final dos RSS, baseando-se na nova política de gerenciamento dos Resíduos. A discussão teórica sobre os RSS visa conscientizar o estabelecimento de saúde, dos problemas em relação aos RSS, identificando os fatores de falhas, agravos e riscos nas áreas críticas, semi-críticas e não críticas, para que este estabelecimento atenda as expectativas da legislação, bem como incorpore ações para uma qualidade de vida ideal da população, do profissional de saúde, através da segurança ocupacional e da preservação do meio ambiente. A metodologia aplicada ao estudo é de natureza descritiva, através de coleta de dados, com roteiro de observações realizadas no Centro de Quimioterapia - CQ do Hospital de Referência de Araguaína - HRA, do município de Araguaina/TO, procurando entender, através de dados estatísticos a relação que o mesmo estabelece entre RSS e a percepção ambiental. Os resultados obtidos neste estudo demonstraram que as diretrizes de manejo destes resíduos são fundamentadas na normatização das resoluções RDC 306/2004 e a CONAMA 358/2005, compreendendo o processo de segregação, acondicionamento, identificação, armazenamento temporário, transporte interno e externo, tratamento, coleta e destinação final. Concluí-se que há necessidade de que seja aplicada, aos profissionais envolvidos no processo, educação continuada para que, junto ao um plano de gerenciamento adequado dos RSS, sejam executadas avaliações constantes e rotineiras destes resultados, com o objetivo de preservar a saúde dos trabalhadores, profissionais, colaboradores, população e ambiental, garantido, assim, melhor qualidade de vida para toda a sociedade e o meio ambiente.

Recently, there has been an enormous growth of interests in geolocation applications that demand an accurate estimation of the user’s location in indoor areas. The traditional geolocation system, GPS, which was designed for being used in outdoor environments, does not perform well in indoor areas, causing frequent inaccuracies in location estimation. Therefore the need for more accurate positioning systems and even positioning techniques is a motivation for researchers to turn their attention into indoor positioning systems. In this thesis we present a unique testbed for indoor geolocation system’s real-time performance evaluation. Then we present a real-time performance evaluation of a sample indoor positioning system. We make a comparison between the simulated results of the performance evaluation of the positioning engine and the real-time performance evaluation of the positioning system. Finally, we perform a sensitivity analysis for Ekahauâ„¢ indoor positioning engine. We show that the simulation with the introduced testbed yields the same results as one would obtain by evaluating the performance of the positioning system by means of massive measurement campaigns. Running the testbed for several measurement campaigns for different scenarios enabled us to compare the results and study the effect of selected parameters on the performance of the positioning system. We also perform primitive error analysis in terms of distance error to verify the validity of the result obtained with the testbed. We show that under the same configuration both real-time performance evaluation and simulated performance evaluation will yield same result with respect to position error. We also use error modeling to determine which error model is best matched to the observed indoor positioning error. Amongst all of the possibilities of choosing methods of positioning, we focused on the Received Signal Strength (RSS) based method along with fingerprinting. Briefly said, profiles previously gathered by measurement or simulation will decide on the location of mobile terminal if a new profile comes in. It is worth mentioning that previous work similar to this testbed has been done for outdoor areas according to Ekahau's white paper. Their work is mainly focused on outdoor environment, in which multipath does not exist. In this research effort we tried to analyze the effect of different parameters on sensitivity of indoor positioning systems who suffer from multipath. Different setups for simulating real-time radio channels have been studied in literature, but still not focused on indoor areas.

Depuis une vingtaine d’années, le Congo de l’Est, est en proie à une instabilité chronique et une insécurité généralisée alimentées, pour une grande part, par une variété d’acteurs armés irréguliers nationaux et transnationaux. Cette situation, qui a causé 15 millions de victimes civiles directes et indirectes, conduit à faire du conflit dans l’Est de la RDC l’un des conflits les plus meurtriers après les deux guerres mondiales. Bien que la présence de ces milices et leurs activités soient reconnues comme imposant une insécurité permanente et épouvantable pour les communautés locales, comme une menace de sécurité et de défense pour l’Etat congolais ainsi que pour la RGL, comme un motif clé de mésentente dans la RGL et des conflits récurrents dans l’Est de la RDC, paradoxalement, l’entreprise de leur démantèlement, élément essentiel du maintien et de la consolidation de la paix dans la région, initiée à la faveur de l’Accord de cessez le feu de Lusaka, reste éminemment une gageure. Comment comprendre et appréhender l’entreprise de leur désarmement ? Quels leviers ont-ils été mise en œuvre en vue de leur démantèlement puis sécurisation du Congo de l’Est ? Quels en sont les enjeux et les contraintes qui sous- tendent cette entreprise ? Le présent travail vise à étudier le processus de désarmement de ces mouvements armés illégaux et de RSS militaire, comme élément du mode de résolution du conflit à l’Est et par extension dans la RGL. / For the past twenty years, the Eastern Congo is witnessing a chronic instability and widespread insecurity. They are caused, for a large part, by a variety of national and transnational illegal armed forces. This situation, which has caused directly and indirectly about 15 million civilian casualties in the eastern DRC and is one of the deadliest conflicts after the two world wars. The presence of these militias and their activities are recognized as a threat to security and defense for the Congolese state and the Great Lakes Region and a key reason for disagreement in the GLR and recurring conflicts in eastern DRC. But paradoxically, the disarming these organizations, as per the Lusaka ceasefire agreement, consolidating peace in the region remains highly challenging. How to understand and grasp the business of their disarmament? What levers they have been implemented with a view to dismantling and securing the Eastern Congo? What are the challenges and constraints that underlie this business? The present work aims to study the process of disarmament of these illegal armed movements and of SSR military, as part of the conflict resolution mode in the East and by extension in the GLR.

Deal Organizer is a web-based application that scans multiple websites for online bargains. It allows users to specify their preferences in order for them to receive notifications based on personalized content. The application obtains deals from other websites through data extraction techniques that include reading RSS feeds and web scraping. In order to better facilitate content personalization, the application tracks the user's activity by recording clicks on both links to deals and rating buttons, e.g., the Facebook like button. Due to the dynamic nature of the source websites offering these deals and the ever-evolving web technologies available to software developers, the Deal Organizer application was designed to implement an interface-based design using the Spring Framework. This yielded to an extensible, pluggable and flexible system that accommodates maintenance and future work gracefully. The application's performance was evaluated by executing resource-intensive tests on a constrained environment. Results show the application responded positively. / text

Η έννοια του «Web2.0.» χρησιμοποιήθηκε για πρώτη φορά σε ένα συνέδριο για την ανταλλαγή ιδεών μεταξύ του εκδοτικού οίκου O’ Reilly και του Medialive International. Μέσα από αυτή τη σύσκεψη έγινε φανερό ότι το Web είναι πιο σημαντικό από ποτέ, με εντυπωσιακές νέες εφαρμογές και ιστότοπους, που κάνουν την εμφάνισή τους ολοένα και συχνότερα. Μισό χρόνο μετά, ο όρος Web2.0. έχει ξεκάθαρα λάβει χώρα, με περισσότερες από 9,5 εκατομμύρια αναφορές στη μηχανή αναζήτησης Google. Πιο συγκεκριμένα, το νέο Web αλλάζει επειδή αλλάζει η νοοτροπία των δημιουργών των ιστότοπων, των προγραμματιστών αλλά και των απλών χρηστών. Το Web2.0. είναι περισσότερο δημοκρατικό. Ο ρόλος των ισχυρών, παραδοσιακών δημιουργών και «εκδοτών» περιεχομένου αποδυναμώνεται. Η αλληλεπίδραση των χρηστών με το περιεχόμενο και άλλους χρήστες εντείνεται. Η νέα χρήση των ήδη υπαρχουσών τεχνολογιών και εργαλείων δίνει καινούριες διαστάσεις και προστιθέμενη αξία στο περιεχόμενο. Οι λέξεις «υλικό» και «λογισμικό» περνάνε σε δεύτερη μοίρα ενώ μια νέα, καθολική πλατφόρμα είναι αυτή που αναδεικνύεται. Ο νέος Παγκόσμιος Ιστός που ακούει στο όνομα Web2.0. ενθαρρύνει τη συμμετοχή των χρηστών και την παραγωγή ενός πλουσιότερου, πιο σύγχρονου και δυναμικότερου περιεχομένου. Προσφέρει σε όλους τους χρήστες του το ρόλο του δημιουργού και του εκδότη αφού ταυτόχρονα με τους web developers, και οι απλοί χρήστες είναι σε θέση να δημιουργούν χρησιμοποιώντας τη θέληση και τη φαντασία τους. Παράλληλα με τη διαμόρφωση του περιεχομένου, διαφόρων μορφών, όπως κείμενο, ήχος, εικόνα, βίντεο, στους χρήστες επαφίεται και η κατηγοριοποίηση, η αξιολόγηση και η κατάταξη του περιεχομένου, όπως για παράδειγμα ποια είδηση θεωρείται από αυτούς ως η περισσότερο σημαντική. Το Web2.0 αναφέρεται σε ένα σύνολο νέων δικτυακών υπηρεσιών, οι οποίες επιτρέπουν στους χρήστες να συνεργάζονται και να ανταλλάζουν δεδομένα online, με πιο αποδοτικό τρόπο σε σχέση με αυτόν που προσφέρανε οι παλιότερες υπηρεσίες. Η ειδοποιός διαφορά είναι ότι οι νέες υπηρεσίες παρέχουν στο χρήστη μια εμπειρία που πλησιάζει περισσότερο σε αυτή που έχει όταν εργάζεται στον προσωπικό του υπολογιστή. Με άλλα λόγια, οι εφαρμογές του Web2.0. μοιάζουν με τις εφαρμογές desktop. Επιπλέον, οι νέοι δικτυακοί τόποι είναι κατά κανόνα «δυναμικοί» και περισσότερο αλληλεπιδραστικοί, διαφέροντας από το «στατικό» Web1.0. Το Web2.0. είναι συμβατό με οποιοδήποτε λειτουργικό σύστημα κι αν χρησιμοποιεί ο εκάστοτε χρήστης. Μια εφαρμογή πλοήγησης του Διαδικτύου (web browser) (οποιαδήποτε κι αν είναι αυτή) αρκεί για να συμμετέχει ένα χρήστης στο νέο, πιο ζωντανό και εκπληκτικό Διαδίκτυο. Επιπρόσθετα, το Web2.0. είναι εκτός από πλούσιο και «ελαφρύ». Πολλές από τις εφαρμογές του έχουν σχεδιαστεί για να «τρέχουν» γρήγορα, χωρίς να «βαραίνουν» τους πόρους του συστήματος. Τέλος, το λογισμικό και το υλικό δεν απασχολούν πλέον τους προγραμματιστές στον ίδιο βαθμό με το παρελθόν, αφού το περιεχόμενο, η διαμόρφωση και η αξιοποίησή του είναι τα θέματα στα οποία επικεντρώνεται κυρίως το ενδιαφέρον. Η παρούσα μεταπτυχιακή διπλωματική εργασία μελετά τις αρχές που το Web2.0. πρεσβεύει, τα πρότυπα σχεδιασμού που ακολουθούνται, τις τεχνικές και τεχνολογίες που χρησιμοποιούνται, τις ικανότητες που πρέπει να έχουν οι εταιρείες κατασκευής λογισμικού και εφαρμογών προκειμένου να θεωρούνται ότι ακολουθούν τα πρότυπα του Web2.0. Επιπλέον, παρουσιάζονται οι βασικότερες Web2.0. εφαρμογές, οι οποίες είτε πρόκειται για καινοτόμα στοιχεία, είτε αποτελούν νέες εκδόσεις των ήδη Web1.0. υπαρχουσών εφαρμογών, με τις οποίες και συγκρίνονται. Τελικά, παρουσιάζονται μια σειρά από ιστοτόπους, ελληνικούς και ξένους, στους οποίους γίνεται φανερή η επίδραση και παρουσία του Web2.0., ενώ παράλληλα προτείνεται η χρήση συγκεκριμένωνWeb2.0. στοιχείων και τεχνολογιών ανάλογα με την κατηγορία και το είδος του ιστοτόπου. Ωστόσο, υπάρχει και ένα μεγάλο ποσοστό που αντιμετωπίζει το Web2.0. με επιφυλακτικότητα. Ενώ κάποιοι το θεωρούν μια καινοτομία, κάποιοι άλλοι το θεωρούν μια χωρίς νόημα λέξη, που αποσκοπεί στην επικράτηση στην αγορά και την αύξηση των κερδών, των εφαρμογών και υπηρεσιών που φέρονται ως αντιπρόσωποι του όρου. Η παρούσα εργασία έχει ως σκοπό να παρουσιάσει αντικειμενικά και αμερόληπτα τη νέα γενιά του Διαδικτύου και αφήνει στον αναγνώστη να βγάλει τα δικά του συμπεράσματα για το τι τελικά είναι το Web2.0. και ποια είναι η αξία του. / The concept of “Web2.0” began with a conference brainstorming session between O’ Reilly and MediaLive International. In the year and a half since, the term “Web2.0” had clearly taken hold, with more than 9.5 million citations in Google. In the new generation of Web, users are treated as co-developers. They obtain the role of author and publisher and use their willingness and imagination to add value and create the content of the web. Leverage customer-self service and algorithmic data management are used in order to reach out to the entire web, to the edges and not just the centre. As a result, the new projects can be seen to have a natural architecture of participation. In some cases, the service automatically gets better the more people use it. Moreover, Web2.0 era software is delivered as a service, not as a product. That leads to an end of the software release cycle. Furthermore, the Web2.0 mindset is good at re-use. When commodity components are abundant, developers can create value simply by assembling them in novel or effective ways. The purpose of this master thesis is to analyse the principles that Web2.0. advocate, the techniques and technologies that are used, the core competencies of Web2.0. companies, the design patterns, the new applications and projects. Its target is to recommend which of the Web2.0’ components should be used in each case, depending on the needs, the requirements and the kind of the website or application. However, there’s still a huge amount of disagreement about just what Web2.0 means, with some people decrying it as a meaningless marketing buzzword, and others accepting it as the new conventional wisdom. This thesis presents Web2.0 impartially, letting readers to decide what is Web2.0 and its value.

Η εργασία αυτή αποτελεί συνέχεια μιας προσπάθειας για την ανάπτυξη της πύλης WEP (Web Engineering Resources Portal). Πρόκειται για ένα Μοντέλο Αναφοράς και μια Πύλη Πόρων που φιλοδοξεί να αποτελέσει ένα σημαντικό εργαλείο για το web engineering, αλλά και αναφορά στην ανάπτυξη εφαρμογών / πληροφοριακών συστημάτων παγκοσμίου ιστού και οδηγό στην ανεύρεση και κατανόηση τεχνολογιών και εργαλείων. Το κομμάτι με το οποίο θα ασχοληθούμε εδώ αφορά το τελευταίο μέρος και τον εκπαιδευτικό χαρακτήρα που επιθυμούμε να προσδώσουμε στην πύλη. Συνοπτικά, η διπλωματική εργασία κινείται σε τρεις άξονες: Πρώτον, στη μελέτη σύγχρονων δυνατοτήτων συλλογής πληροφορίας για την επιλογή των κατάλληλων εργαλείων για εισαγωγή στην πύλη και την ανάπτυξη της δικής μας μεθοδολογίας. Η διαρκής και ραγδαία αύξηση του όγκου των δεδομένων κατέστησε εμφανές το πρόβλημα της ευρέσεως και εξαγωγής της ''χρήσιμης'' ή ''επιθυμητής'' πληροφορίας, καθώς για κάθε κατηγορία ιστοεφαρμογών υπάρχει μια πληθώρα εργαλείων ανάπτυξης (τα οποία μάλιστα διαρκώς ανανεώνονται) καθιστώντας τη διαδικασία επιλογής των καταλληλότερων ιδιαίτερα επίπονη και χρονοβόρα. Δεύτερον, στην εφαρμογή της παραπάνω μεθοδολογίας εργασίας με στόχο την εισαγωγή των αντίστοιχων εργαλείων που προέκυψαν με τη μετατροπή της πληροφορίας σε XML για τη δόμηση της πύλης WEP. Εξηγούμε πως έγινε η εισαγωγή και διαχείριση περιεχομένου με χρήση της τεχνολογίας XML και πως καταλήγουμε στην υλοποίηση των παραπάνω μέσα από την πλατφόρμα του stringbeans. Τρίτον στον εκπαιδευτικό χαρακτήρα της Πύλης. Αναφερόμαστε στις έννοιες του e-learning, και τις διάφορες εναλλακτικές που υπάρχουν στο χώρο της ηλεκτρονικής μάθησης στην εποχή του Web 2.0, όπου οι χρήστες συμμετέχουν ενεργά στη συγγραφή του εκπαιδευτικού υλικού. Αναλύουμε τα χαρακτηριστικά των PLE (Personal Learning Environments) και των LMS (Learning Management Systems) και εκθέτουμε πλεονεκτήματα και μειονεκτήματά τους. Τέλος, καταλήγουμε σε μια γενική αξιολόγηση της προσπάθειάς μας, καταγράφοντας τα αποτελέσματα και τους στόχους που υλοποιήθηκαν, τα συμπεράσματα και τις προτάσεις μας. / This paper is a follow up of the previous work concerning the Web Engineering Resources Portal (shortly WEP). It consists of a Reference Model and a Resources Portal. The aim of WEP is to provide a tool for web engineering as well as a reference for the development of applications / information systems and a guide for finding and understanding web engineering technologies and tools. Here we deal with that last part and the educational aspect of WEP which we are trying to achieve. Briefly, the thesis involves three parts: Firstly, the study of modern possibilities for collecting and importing information regarding the choice of suitable tools and the development of our own methodology. The rapid growth of data volume rendered obvious the problem of finding and extracting of ''useful'' or ''desirable '' information, since there is an abundance of development tools (which are indeed constantly renewed) for every category of web application making the process of choosing the most suitable ones particularly laborious and time-consuming. Secondly, it refers to the enforcement of the above methodology aiming at the import of resultant tools with the transformation of information in XML for the layout of WEP. We explain the way the import and management of content using XML technology is completed and we come to the adaptation and implementation phase through the Stringbeans framework. Thirdly we try to highlight the educational character of WEP portal. The concept of e-learning is described and the various alternatives at the age of Web 2.0, where the users participate actively in the writing of educational material are taken into consideration. Furthermore, we analyze the characteristics of PLE (Personal Learning Environments) and LMS (Learning Management Systems) quoting advantages and disadvantages of both. Finally, we lead to a general evaluation of our effort, mentioning the results and the objectives that were achieved, the conclusions and our proposals for the future.

Malaria affects millions of people annually especially in third world countries. Increase in resistance and limited research being conducted adds to the global burden of malaria. Mefloquine, known for unwanted adverse reactions and neurotoxicity, is highly lipophilic and is still used as treatment and prophylaxis. Lipid drug delivery systems are commonly used to increase solubility and efficacy and decrease toxicity. The most generally used lipid drug delivery system is liposomes. The lipid bilayer structure varying in size from 25 nm to 100 μm can entrap both hydrophilic and lipophilic compounds. Similar in structure and size to liposomes, Pheroid™ technology consist of natural fatty acids and is also able to entrap lipophilic and hydrophilic compounds. The aim of this study was to formulate liposomes and Pheroid™ vesicles loaded with mefloquine and evaluate the physiochemical characteristic of the formulations followed by efficacy and toxicity studies. Pheroid™ vesicles and liposomes with and without mefloquine were evaluated in size, morphology, pH and entrapment efficacy during three month accelerated stability testing. Optimization of size determination by flow cytometry lead to accurate determination of size for both Pheroid™ vesicles and liposomes. During the three months stability testing, Pheroid™ vesicles showed a small change in size from 3.07 ± 0.01 μm to approximately 3 μm for all three temperatures. Confocal laser scanning microscopic evaluation of the liposomes showed structures uniform in spherical shape and size. No difference in size or structure between the Pheroid™ vesicles with and without mefloquine were obtained. Significant increase (p=0.027) in size from 6.46 ± 0.01 μm to above 10 μm was observed for liposomes at all the temperatures. Clearly formed lipid bilayer structures were observed on micrographs. With the addition of mefloquine to the liposome formulation, a decrease in the amount of bilayer structures and an increase in oil droplets were found. Entrapment efficacy was determined by firstly separating the entrapped drug from the unentrapped drug utilizing a Sephadex®G50 mini column. This was followed by spectrophotometric evaluation by UV-spectrophotometry at 283 nm. Initial entrapment efficacy of both Pheroid™ vesicles and liposomes was above 60%. An increase in entrapment efficacy was observed for Pheroid™ vesicles. The addition of mefloquine to already formulated Pheroid™ vesicles illustrated entrapment efficacy of 60.14 ± 5.59% after 14 days. Formulations loaded with mefloquine resulted in lower pH values as well as a decrease in pH over time. Optimization of efficacy studies utilizing propidium iodide was necessary due to the similarity in size and shape of the drug delivery systems to erythrocytes. A gating strategy was successfully implemented for the determination of the percentage parasitemia. Efficacy testing of mefloquine loaded in Pheroid™ vesicles and liposomes showed a 186% and 207% decrease in parasitemia levels compared to the control of mefloquine. Toxicity studies conducted include haemolysis and ROS (reactive oxygen species) analysis on erythrocytes as well as cell viability on mouse neuroblastoma cells. Pheroid™ vesicles with and without mefloquine resulted in a dose dependent increase in ROS and haemolysis over time. A dose dependent increase in ROS and haemolysis in both liposome formulations were observed, but to a lesser extent. Mefloquine proved to be neurotoxic with similar results obtained when mefloquine was entrapped in liposomes. Pheroid™ vesicles seem to have neuroprotective properties resulting in higher cell viability. Mefloquine could be entrapped successfully in Pheroid™ vesicles and less in liposomes. Pheroid™ vesicles was more stable over a three months accelerated stability testing with more favourable characteristics. The increase in ROS levels of Pheroid™ vesicles could be responsible for the higher efficacy and haemolytic activity. DL-α-Tocopherol in Pheroid™ vesicles possibly acted as a pro-oxidant due to the presence of iron in the erythrocytes. DL-α-Tocopherol showed possible antioxidant properties in the neurotoxicity evaluation resulting in higher cell viability. Even though liposomes illustrated higher efficacy and little haemolysis and ROS production, no difference in neurotoxicity was observed together with unfavourable properties during stability testing makes this drug delivery system less favourable in comparison to Pheroid™ vesicles. Mefloquine was successfully incorporated into Pheroid™ vesicles resulted in high efficacy and showed possible neuroprotection and therefore makes it an ideal system for treatment of malaria. / Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011

Wireless Sensor Networks (WSNs) have gained significant consideration these days, as opposed to wired sensor networks, by introducing multi-functional wireless nodes, which are smaller in size. The main advan-tage is that its wireless, so it costs less to install, maintain and reconfig-ure. These sensor nodes are used in various application areas. For ex-ample: residential, industrial, environmental and military application areas. However WSNs communication is prone to negative influences from the physical environment, such as physical obstacles and interfer-ence. Algorithms must be developed for handling these problems and also to investigate the channel properties. The purpose of this work is to design a testbed, which enables the communication of wireless sensor nodes, to capture the properties of the channel, which will, in the long run, enable better solutions to be designed which are, more appropriate to the errors in the channel. In this testbed, one channel, from the IEEE 802.15.4 channels spectrum, is dedicated as an emergency channel, which is used for handshaking and to handle channel/external interfer-ence or hardware failure between the communication of Transmitter (TX) and Receiver (RX) nodes. The remaining 15 channels are called data channels and are used for actual data transmission and control signals. Peer to Peer transmission of a transmitter-receiver pair is achieved with the introducing of beacons and acknowledgment (ACK) packets. The testbed also has the property of dual reception and data logging on a single PC by maeans of two RX nodes simultaneously from a single TX node. The dependency of the packet on the “Frame Length” byte(in the Frame header) during the reception is eliminated so that if the “Frame Length” byte is compromised, it will replace the programmer defined value with the “Frame Length” byte which helps to investigate the actual packets byte sent from the TX. Also, the Received Signal Strength (RSS) is calculated at the maximum sample rate of the channel. Power consumption is not considered in this testbed. The work is conducted on both the IEEE 802.15.4 physical and the application layers. Linux based TinyOS-2.x is used as an operating system for low power sensor devices. New algorithms are designed for each step in the development of the testbed. MICAz motes are used as nodes and an MIB520 programming board is used for burning the codes and for the purpose of gateways.