Tesis sobre el tema "C-384"

Drahtlose ad-hoc Netzwerke zwischen Fahrzeugen, sog. Vehicular ad-hoc Networks (VANETs), bilden einen Ansatz zur Verbesserung der Verkehrssicherheit, indem sie zukünftige kooperative Fahrerassistenzsysteme ermöglichen. Diese Netzwerke erfordern ein hohes Sicherheitsniveau, sowohl in Bezug auf Datenintegrität und -authentizität als auch im Bereich Datenschutz. Aktuell verfügbare Technologien können diese Anforderungen nicht vollständig erfüllen. Etliche Nachteile aktueller VANET-Ansätze werden in dieser Arbeit aufgezeigt. In dieser Arbeit werden drei Schachpunkte von ETSI ITS bzw. WAVE basierten VANETs identifiziert, welche Angriffe auf Teilnehmer dieser Netzwerke ermöglichen. Diese ergeben sich aus 1. konstanten und für Teilnehmer charakteristischen Datensätzen innerhalb der zyklisch versandten Statusnachrichten, welche den Datenschutz der Fahrzeuge und damit auch ihrer Fahrer gefährden, 2. die Strategie zur Verteilung von digitalen Zertifikaten von Zertifizierungsstellen erlaubt es selbst Angreifern mit minimalen Fähigkeiten (einzelner, statischer Angreifer von außerhalb des Netzwerkes) die Kanallast in einem großen Teilgebiet des Netzwerkes massiv zu erhöhen, 3. GNSS Manipulation durch sog. spoofing erlaubt Angriffe auf zeit- und ortsbasiere Informationen in Fahrzeugen, wodurch sich folgende Gefährdungen ergeben: a. Der Grundanforderung Teilnehmer durch Nichtabstreitbarkeit der gesendeten Daten für ihr Verhalten zur Rechenschaft ziehen zu können wird die Grundlage entzogen, da der Zeitpunkt des Sendens der Daten nicht mehr sicher festgestellt werden kann. b. Die Zugangskontrolle zum System wird gefährdet, da angegriffene Teilnehmer veraltete Nachrichten und digitale Zertifikate akzeptieren. c. Angreifer können einen sog. Sybil Angriff durchführen. Es ist notwendig die identifizierten Sicherheitsprobleme zu beheben um eine sichere Verwendung von VANETs für zukünftige kooperative Fahrerassistenzsysteme zu ermöglichen. Weiterhin werden einige Designprobleme in ETSI ITS Protokollen identifiziert. Die bisherige Art der Nachrichtenzusammensetzung auf den einzelnen Protokollschichten führt häufig zu Gesamtnachrichten, welche die zulässige maximale Gesamtlänge auf niedrigen Protokollschichten überschreitet. Da solche Nachrichten nicht versandt werden könne, können diverse wichtige Datensätze nicht im Netzwerk verteilt werden. Außerdem ist keine verschlüsselte Ende-zu-Ende Kommunikation über eine Multi-Hop Verbindung möglich, da die notwendigen Routing-Informationen den weiterleitenden Teilnehmern nicht zur Verfügung stehen. Es werden Vorschläge diskutiert, wie diese Probleme gelöst werden können. Zur Adressierung der genannten Probleme werden u.a. folgende Maßnahmen vorgeschlagen: 1. Eine sichere Zeitsynchronisierung in VANETs ist notwendig. 2. Das Speichern von mehreren Fahrzeug-Zertifikaten mit gleicher Laufzeit ist zu vermeiden. 3. Das Speichern von Fahrzeug-Zertifikaten mit zukünftiger Laufzeit ist auf ein Minimum zu begrenzen. 4. Konstante und gleichzeitig für Teilnehmer charakteristische Datensätze sind nicht zu versenden. 5. Weitere Mechanismen zur Minimierung der Kanallast durch Zertifikatsverteilung sind notwendig, u.a. a. nach einem Pseudonymwechsel sollte dieser explizit signalisiert werden um das Versenden aller Zertifikate in der Umgebung durch die Detektion eines neuen Nachbarn zu verhindern. b. es sollte keine Verteilung von Zertifikatsketten erfolgen, da einzelne Zertifikate ausreichen. c. die Anzahl der Übermittlungen von Zertifikaten von Zertifizierungsstellen ist zu minimieren. Die Anwendung der genannten Verbesserungen überwindet die meisten Sicherheitsprobleme (1,2, und 3c). Für die weiteren Probleme kann der notwendige Aufwand für einen erfolgreichen Angriff deutlich erhöht werden.
Vehicular ad-hoc networks (VANETs) are an important approach to increase future safety of driving by enabling cooperative advanced driver assistance systems. However, rigid security and privacy requirements employed to conducted wireless data exchange still pose significant challenges for VANET approaches. Several weaknesses of the current state of the art of VANET approaches from ETSI ITS as well as WAVE standard frameworks have been identified in this work. Three main attack surfaces of ETSI ITS or WAVE based VANETs are identified in this thesis, which are 1. constant and distinctive content in data fields within frequently sent VANET messages highly endanger privacy of vehicles, and thereby also their drivers, 2. the distribution strategy of certificate authority (CA) certificates allows even a simple static outsider attacker to massively increase the channel load within a large area around the attacker, which significantly exceeds his own communication range, and 3. GNSS spoofing modifying time and position information inside nodes a. endangers the basic system requirement of accountability by circumventing the nonrepudiation feature of the employed digital signature scheme, b. endangers the access control system by forcing the acceptance of outdated messages and certificates, and c. enables an attacker to perform a Sybil attack. The identified security problems need to be overcome to re-enable secure usage of VANETs and ADASs, which are based on the information obtained via VANETs. Several protocol design weaknesses of the ETSI ITS approach have been identified. It is found that the standardized way of cross layer message assembly leads to frequent violation of low layers’ maximum packet size restrictions. This causes inabilities to distribute important data sets from the application layer. Furthermore, confidential end-to-end encrypted communication over a multi-hop connection is impossible, as forwarders cannot access required routing information. This is caused by incorrect data encryption rules. Approaches to overcome the found shortcomings are proposed and evaluated. To overcome the outlined security issues, several improvements have been proposed. These include, 1. secure time synchronization among nodes, but current mechanisms can hardly provide it, 2. caching of multiple pseudonym certificates being valid during the same time span is to be avoided, 3. pre-caching of pseudonym certificates valid in the future is to be limited to a minimum, 4. presence of constant but distinctive data sets within VANET messages has to be avoided to enable privacy conserving pseudonym changes, 5. mechanisms for limiting the channel load caused by certificate distribution are required, especially a. after a pseudonym change the number of superficial pseudonym certificate distributions due to new neighbor detection should be limited by using explicit signaling of the change, b. sending of certificate chains should be removed altogether, instead individual dissemination should be used for CA certificates, and c. the number of CA certificate deliveries after a request for such a kind of certificate should be limited to a minimum by using targeted requests. By employing the given improvements most of the found security weaknesses can be overcome (issues 1, 2 and 3c). For the remaining weaknesses the required capabilities for a successful attack can be made significantly more challenging.

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In this thesis, we aim to conduct a study and reconstruction of the criticism that Galileo undertakes to physics and cosmology of Aristotle, and works as an anchor Sidereus Nuncius and First Day of Dialogue Concerning the Two Chief World Systems. The arguments developed by Italian physicist these works, consolidating the Copernican theory and revolutionize the way we study nature. For centuries, the Western conception of the universe was supported by the assumptions of cosmology of Aristotle. Aristotelian cosmology had as fundamental points the idea of the incorruptibility of the heavens, the earth and the immobility of a hierarchy of elements. For the peripatetic, the cosmos was finite and heterogeneous, and was divided into two distinct regions: the sublunary (terrestrial) and above the Moon (heavenly). The telescopic observations made by Galileo in 1609, showing craters and mountains on the moon and Jupiter's satellites, were in evidence against the heaven-earth dichotomy proposed by Aristotle. For it revealed "imperfections" in the heavenly bodies, and showed that not all the stars had their revolutions as the center of the Earth, the idea of asking the same centrality in the cosmos. Moreover, the break with Aristotelian cosmology destabilizing the very physics of Aristotle, whose explanation of the movements of bodies depended on the cosmological structure, since there were three types of moves, straight toward the center, straight away from the center and circular around the center, which required a motionless earth occupying the center of the cosmos. The idea of centrality and immobility of the Earth is therefore fundamental point of Aristotelian physics and cosmology. Most of the work of Galileo Galilei seems to think about a central objective: the defense of the Copernican theory. Since his public adhesion to the Copernicanism in 1610, in Sidereus Nuncius, until Dialogue published in 1632, the Pisan Phisycist sought to break with the assumptions of the Aristotle s natural philosophy which supported the geocentric conception. As a result, it is in First Day of Dialogue that, certainly, we could find a more systematic and focused effort against the Aristotelic conception of world and its main characteristic: the dissociation of the cosmos into two distinct regions, the celestial and sublunary.
Nesta dissertação, temos como objetivo realizar um estudo e reconstrução das críticas que Galileu empreende à física e à cosmologia de Aristóteles, tendo como âncora as obras Sidereus Nuncius e Primeira Jornada do Diálogo sobre os dois máximos sistemas do mundo. Os argumentos desenvolvidos pelo físico pisano nestas obras, consolidam a teoria copernicana e revolucionam a maneira de se estudar a natureza. Durante séculos, a concepção ocidental de universo esteve apoiada nos pressupostos da cosmologia de Aristóteles. A cosmologia aristotélica tinha como pontos fundamentais a ideia de incorruptibilidade do céu, de imobilidade da Terra e de uma hierarquia dos elementos. Para o peripatético, o cosmos era finito e heterogêneo, e se encontrava dividido em duas regiões distintas: a sublunar (terrestre) e a supralunar (celeste). As observações telescópicas realizadas por Galileu em 1609, ao mostrar crateras e montanhas na Lua, e satélites em Júpiter, constituíram-se em evidências contrárias à dicotomia céu-Terra proposta por Aristóteles. Pois revelavam imperfeições nos corpos celestes, e mostravam que nem todos os astros tinham como centro de suas revoluções a Terra, questionando a ideia de centralidade da mesma no cosmos. Além disso, a ruptura com a cosmologia aristotélica desestabilizava a própria física de Aristóteles, cuja explicação dos movimentos dos corpos dependia da estrutura cosmológica, uma vez que existiam três tipos de movimentos: retilíneo em direção ao centro, retilíneo se afastando do centro e circular em torno do centro, o que requeria uma Terra imóvel ocupando o centro do cosmos. A ideia de centralidade e imobilidade da Terra é, portanto, ponto fundamental da física e da cosmologia aristotélicas. Grande parte da obra de Galileu parece girar em torno de um objetivo central: a defesa da teoria copernicana. Desde a sua adesão pública ao copernicanismo em 1610, no Sidereus Nuncius, até o Diálogo publicado em 1632, o físico pisano buscou romper com os pressupostos da filosofia natural de Aristóteles que sustentavam a concepção geocêntrica. Com efeito, é na Primeira Jornada do Diálogo que poderemos encontrar um esforço mais sistemático e concentrado contra a concepção aristotélica de mundo e sua principal característica: a dualidade do cosmos.

Constituée en discipline autonome de l’art de la guerre dès la fin du Ve av. JC, la poliorcétique, qui apparait comme une pratique inséparable de la τέχνη, a suscité un travail de conceptualisation favorisant l’éclosion d’une littérature spécialisée. Ainsi, il n’y a rien de fortuit à ce que l’un des plus anciens traités militaires – Αἰνείου πολιορκητικά – lui ait été consacré. Daté de 357/55, l’ouvrage d’Enée le Tacticien fut à l’origine d’une tradition littéraire qui se termina, sept siècles plus tard, avec l’Epitoma de Végèce. Riche de quatorze traités, ce legs du passé forme le corpus systémique de la poliorcétique antique, objet de notre recherche ; elle s’articule autour de deux axes. Premièrement, il convenait, d’une part, de présenter les auteurs de ces traités qui n’étaient pas tous des professionnels de la guerre. D’autre part, nous devions mettre en exergue l’étonnante modernité de ces traités. Une qualité qui leur confère un caractère universel et intemporel ; sans cette vertu, ces traités eussent-ils été repris comme ils le furent à la Renaissance ? L’Art de la guerre n’était-il pas déjà en devenir dans ces textes ? De surcroît, nous avons tenté de dégager une figure, celle de l’écrivain militaire de l’Antiquité. Le deuxième axe de cette recherche ressortit aux machines de siège et leur mise en batterie ainsi qu’aux tactiques des combattants, ce sont-là les thèmes principaux de ces traités qui n’ignorent pas la fortification. En ce domaine, Philon de Byzance fit oeuvre de théoricien
Formed as an autonomous field of study of the art of war as early as the end of the 5th century BC, poliorcetics – a practice inseparable from τέχνη – has generated a work of conceptualisation favouring the development of a specific literature. Hence that one of the oldest military treatises – Αἰνείου πολιορκητικά – was devoted to it is in no way fortuitous. Dating back to the 4th century BC, Aeneas Tacticus’s work prompted a new literary tradition which ended, seven centuries later, with Vegetius’s Epitoma. This legacy from the past forms a systemic corpus: that of early poliorcetics, which is the focus of our research, based on two issues. To begin with, is was advisable to introduce as a matter of fact, all of them were not soldiers or in the military. Then, we had to point out the surprising modernity of these ols treatises. This quality gives them a universal and timeless character. Without it, would such treatises have been taken up as they were during the Renaissance? In addition, we have tried a character to come out : the military writer of this time. The second deals with combatants’ tactics and war machines, as main themes of those treatises that did not ignore fortifications. In that field, Philo of Byzantium took on the role of theoretician

This thesis argues that the origins and evolution of Christian communities in Northern Italy between c. 250 and 381 are comprehensible only within the region's social environment. Whereas previous studies of early Christianity in Italy have sought to explain its origins in terms of modern diocesan structures, this thesis shows that the evidence for this view is untrustworthy and that a new methodology is needed to explain the rise of the church. To this end, the thesis describes the 'north Italian human environment', which consists not just of the physical landscape, but of the social networks within it. This environment allows an understanding of why Christian communities had developed in some places and not in others by c. 300. The development of the church continued to be influenced by this human environment in the fourth century. Christian diffusion remained a partial and variable phenomenon. In the cities Christians found themselves confronted by the adherents of other religions, notably Judaism. Thus, in the fourth century, Christians did not yet dominate the communities in which they lived. Moreover, the active participation in ecclesiastical affairs of emperors after Constantine - particularly the intervention of Constantius II in Italy during the 350s - added a new dimension to the human environment. Such interventions defined how north Italian Christianity came into contact with ecclesiastical and theological affairs throughout the empire. In sum, the history of early Christianity in northern Italy is circumscribed by the social environment within which it developed. This thesis argues that for northern Italy - indeed for the rest of the Mediterranean - a proper understanding of Christian growth can only come from an appreciation of the particular social context of the region within which it occurred.

Geology
M.S.
Dissolution experiments were conducted on bioapatite at 4°C, 21°C and 38°C and solution pH values between 2 and 8 in a stirred tank reactor. The bioapatite was obtained from modern white-tailed deer (Odocoileus virginianus) scapulae, crushed, and cleaned in 30% hydrogen peroxide to remove organic matter. The average BET specific surface area of the 75-106 and 106-246 μm particles was 255 m2 g-1. During experiments the ratio of Ca:P released became stoichiometric at ca. 1.44. The following dissolution rate law was derived from the experimental results: R = K1(H+)ⁿ+K2 in which R is the dissolution rate (mol bioapatite m-2 s-1) based on the bioapatite stoichiometry, n = 1.01 ± 0.15, k1 = 1.84 x 10-6 ± 1.71 x 10-6 mol m-2 s-1, and k2 = 4.29 x 10-10 ± 1.15 x 10-10 mol m-2 s-1 and H+ is the hydrogen ion activity. From 2 < pH < 4, dissolution rate is dependent on pH and becomes independent of pH from 4 < pH < 8. These results for modern bone may be compared with previous investigations of igneous (FAP) and phosphorite-derived sedimentary carbonate fluorapatites (CFA)(e.g., Guidry and Mackenzie, 2003). At pH = 6, in the pHindependent region, dissolution of the modern bioapatite was ca. 7 times faster than FAP and 100 times faster than CFA. The acid transition pH of the bioapatite (pH = 4) is lower than that for FAP (pH = 6). Bioapatite dissolution rates influence fossil preservation potential, the release rate of nutrients from bone meal fertilizers, the effectiveness of bone as reactive barriers to control pollutants and nuclear waste isolation, and as a feedstock material in CO2 sequestration processes.
Temple University--Theses

Der Beitrag fragt, wie Musik das Phänomen des unmittelbaren körperlichen Schmerzes aufnimmt und wie sie es im Rahmen von Form und Ästhetik einer in festen Traditionen vorgeprägten kammermusikalischen Gattung gestaltet.

Tato práce se zabývá běžnými problémy časových politik, které jsou využívány v rámci procesu přihlašování uživatelů. Jsou rozebrána řešení v některých jiných současných systémech. Dále je čtenáři představen projekt pro správu identit FreeIPA, autor se zaměřuje hlavně na správu uživatelů a politiky pro jejich autorizaci. Je také představen projekt SSSD se zaměřením na jeho propojení se systémem FreeIPA. Po vytvoření návrhu řešení problému časových politik je tento návrh implementován do systémů FreeIPA a SSSD.

La présente etude est consacrée à l'édition de trente-six chansons pieuses anaonymes transmises en grande partie par des chansonniers français V (Paris, Bibliothèque Nationale de France, fr. 24406) et C (Bern, Burgerbibliothek 389). Plusieurs indices nous ont fait supposer que le même recueil de chansons pieuses a servi de source à V et C, mais que chacun des copistes a eu accès à un représentant différent de la tradition. E. Schwan avait d'ailleurs reconnu la source commune aux deux chansonniers et l'avait indiquée par l'abréviation Vg. L'édition reproduit les chansons selon l'ordre V, qui nous a vraisemblablement transmis le recueil dans l'ordre primitif. C'est aussi V qui a été retenu comme manuscrit de base, car il est plus correct et sa scipta est moins marquée dialectalement que celle de C. L'apparat est négatif ; il est disposé sur deux niveaux : les leçons refusées dans la partie supérieure et les variantes des autres sources manuscrites dans la partie inférieure, en transcription diplomatique. Toutes les variantes graphiques ont été relevées de manière à ce que le lecteur puisse se faire une idée de la scipta de chacun temoin. L'étude des mélodies du corpus nous a permi de confirmer ce que nous avions déjà vérifié lors de cette étude de textes eux-mêmes : nos chansons pieuses reprennent souvent des airs ou des schémas métriques déjà utilisés par des trouvères ou troubadours bien connus, comme Gace Brulé, Thibaut de Champagne, Gautier d'Espinal, Guiot de Provins, Robert de Castel, Jacques de Cambrai, Moniot d'Arras, Jacques le Vinier, Rigault de Berbezilh, Folquet de Marseille
The present study consists in a critical edition of thirty-six anonymous religious French poems mainly transmitted by French chansonniers V (Paris, Bibliothèque nationale de france, fr. 24406) et C (Bern, Burgerbibliothek 389). Several elements made us think that a same collection of religious poems has been the source for V and C, but the two scribes copied from different branches of tradition. E. Schwan already recognised the common source to both manuscripts and indicated it with Vg. The songs of this edition follow ms. V's presentation, which transmitted the collection in the original order. Ms V is also taken as main source for the edition, as it is more correct and its scripta, if compared to C's one contains just few dialectical traces. The melodies's study of the collection confirmed what we had noticed during the texts'analysis: the religious poems are often composed on melodies and metrical schemes which existed and belonged to well known trouvères or troubadours, as Gace Brulé, Thibaut de Champagne, Gautier d'Espinal, Guiot de Provins, Robert de Castel, Jacques de Cambrai, Moniot d'Arras, Jacques le Vinier, Rigaut de Berbezilh, Folquet de Marseille

La comédie d’Aristophane est abondamment reçue et réécrite par la littérature grecque de l’époque impériale. À partir de l’histoire de la transmission des pièces, rarement rejouées entre leur création et les deux premiers siècles de notre ère, mais diffusées et réinterprétées par différents canaux, iconographiques ou textuels, la thèse étudie la place et le rôle de ce théâtre dans le paysage culturel du Haut-Empire, et plus spécifiquement chez les prosateurs grecs. Le statut de ce théâtre paraît de prime abord problématique : il est souvent entouré de silence, voire d’un blâme théorique, surtout quand on l’oppose à Ménandre ; mais les écrivains, dans des genres et des formes très variés, se le sont pleinement approprié. De nombreux enjeux caractérisent la réécriture des comédies : enjeux historiques et linguistiques, grâce à l’ancrage des textes dans un contexte et une langue attiques et à la réserve de realia que représentent les comédies et qui contribuent à instaurer et affermir l’hellénisme des pépaideumenoi de l’Empire ; enjeux moraux et comiques, notamment par la satire et la parodie ; plus largement, des enjeux poétiques et rhétoriques : ce théâtre est devenu un vecteur reconnu d’images et un garant de créativité et d’autorité. Deux études de cas portent sur des auteurs emblématiques de la période, Plutarque de Chéronée et Lucien de Samosate : les usages qu’ils font de la référence aristophanienne sont protéiformes et marqués par une grande ambiguïté, que cette thèse tente d’élucider
The reception of Aristophanes’s comedy in the Greek literature of the Roman Empire is extensive. Based on the history of transmission of the comedies, which from their creation to the the first two centuries AD were rarely performed on stage but spread and re-interpreted by different means, whether iconographic or textual, this dissertation studies the place and role of this theatre in the cultural landscape of the Roman Empire, specifically in the work of Greek prose writers. The status of this theatre seems at first sight quite problematic: it is rarely mentioned and if mentioned it is spoken of with theoretical disapproval, yet the writers, in various literary genres and forms, fully appropriated it. The rewriting of the comedies is at stake on many levels: on the historic and linguistic levels, in the light of how these texts are anchored in the Attic context and language, and the stock of realia they contain, which contributes to demonstrating the "pepaideumenoi"‘s hellenism in the Empire; on the moral and comic levels, too, as well with satires and parodies; and to a larger extent on the poetic and rhetorical levels, this theatre becomes a conveyor of images and guaranteeing creativity and authority. Two case studies were presented here about emblematic writers of the imperial period, Plutarch of Chaeronea and Lucian of Samosata: they make protean and ambiguous use of the reference to Aristophanes, that this dissertation attempts to clarify

A large MULANA based analysis package, written in FORTRAN, for computing the cross section for proton - nucleus collisions at 400 GeV/c momentum from data taken in experiment E609 at FNAL, was implemented on a Z-386, 16 MHz microcomputer workstation featuring an 80 Mbyte hard drive, and a three Gbyte 8-mm Exebyte tape drive, based in the Ball State High Energy Physics Laboratory, in a feasibility study of conducting such analysis on a workstation as a viable alternative and/or adjunct to the Ball State University VAX system. One of 40 large 1600 bpi 9-track data tapes from Experiment 609 provided the data file for the computation. The analysis package was first run on the VAX system. Special problems solved in connection with using the software package included converting the large data file to a suitable form for use at the workstation, transporting that file from the VAX to the workstation, modifying the VAX FORTRAN software package for implementation in the OS/2 workstation operating system environment, and graphical exposition of the results. With the results of conducting the analysis on the VAX system serving as a benchmark, it was determined first that the quantitative analysis results were identical, second, that computing times were similar, and third that the workstation provided unique conveniences. Overall, the results showed that the workstation is a reasonable alternative to using the VAX for High Energy Physics analysis work but also suggest the attractiveness of using similar but faster workstations in the near future.
Department of Physics and Astronomy

Ce travail etudie les systemes pouzzolanes naturelles-chaux-eau a 38 et 100c afin de comprendre les phenomenes physicochimiques caracterisant la pouzzolanicite des materiaux naturels. La mise en evidence de nouveaux criteres physicochimiques correlant la mineralogie des produits d'hydratation, les qualites mecaniques des melanges pouzzolanes-chaux-eau nous permet de proposer une nouvelle classification des materiaux pouzzolaniques. Cette classification repose sur: une caracterisation et une quantification des constituants reactifs (les verres volcaniques non rhyolitiques, les opales, les zeolites), une etude des solides neoformes et des solutions issus de l'essai chapelle (16 h a 100c dans une solution saturee de chaux), une etude mineralogique et morphologique des phases cristallines neoformees, issues du systeme pouzzolanes-chaux-eau a 38, constituant la matrice des pates durcies. L'ensemble de ces observations montre que les silices sedimentaires, les roches volcaniques et l'alumine activee constituent une serie homologue discontinue a 38 et 100c dans le systeme cao-sio2-al203-h20. Ces materiaux s'illustrent par la coexistence entre la fraction siliceuse de la solution solide des hydrogrenats et des gels silicocalciques hydrates (partiellement alumineux) a 100c et la coexistence entre la solution solide des silicoaluminates tetracalciques hydrates et les gels silicocalciques hydrates

This thesis draws on David Harvey’s concept of “accumulation by dispossession” and an international political economy (IPE) approach centred on the institutional arrangements and power structures that privilege certain actors and values, in order to critique current capitalist practices of primitive accumulation by the global corporate extractive industry. The thesis examines how accumulation by dispossession by the global extractive industry is facilitated by the “free entry” or “free mining” principle. It does so by focusing on Canada as a leader in the global extractive industry and the spread of this country’s mining laws to other countries – in other words, the transnationalisation of norms in the global extractive industry – so as to maintain a consistent and familiar operating environment for Canadian extractive companies. The transnationalisation of norms is further promoted by key international institutions such as the World Bank, which is also the world’s largest development lender and also plays a key role in shaping the regulations that govern natural resource extraction. The thesis briefly investigates some Canadian examples of resource extraction projects, in order to demonstrate the weaknesses of Canadian mining laws, particularly the lack of protection of landowners’ rights under the free entry system and the subsequent need for “free, prior and informed consent” (FPIC). The thesis also considers some of the challenges to the adoption and implementation of the right to FPIC. These challenges include embedded institutional structures like the free entry mining system, international political economy (IPE) as shaped by international institutions and powerful corporations, as well as concerns regarding ‘local’ power structures or the legitimacy of representatives of communities affected by extractive projects. The thesis concludes that in order for Canada to be truly recognized as a leader in the global extractive industry, it must establish legal norms domestically to ensure that Canadian mining companies and residents can be held accountable when there is evidence of environmental and/or human rights violations associated with the activities of Canadian mining companies abroad. The thesis also concludes that Canada needs to address underlying structural issues such as the free entry mining system and implement FPIC, in order to curb “accumulation by dispossession” by the extractive industry, both domestically and abroad.

博士
中國醫藥大學
藥物化學研究所
92
We previously reported that HMJ-38 was the most potent 2-phenyl-4-quinazolinone derivative in inhibiting tubulin polymerization and showed significant cytotoxicity against several human tumor cell lines. In this study, we studied its cytotoxic effect on HL-60 leukemia cells and underlying mechanisms and investigated the anticancer activity of HMJ-38 in syngeneic BALB/c mice bearing murine WEHI-3 leukemia cells. We first investigated the effects of HMJ-38 on viability, cell cycle and induction of apoptosis in leukemia cell lines (HL-60, U937 and K562) and normal human peripheral blood mononuclear cells. After 24 hours of treatment with HMJ-38, concentration- and time-dependent decreases in the viability of HL-60, U937 and K562 cells were observed and the IC50 value were estimated to be 4.48, 5.06 and 8.87 M. The cytotoxic effect of HMJ-38 on PBMC was less significant than that on HL-60 cells after 24 or 48 hours of treatment. Immunocytochemistry staining of -tubulin demonstrated that, which was also observed in colchicine-treated cells, HMJ-38 inhibited the polymerization of microtubules. Cell cycle analysis showed that HMJ-38 induced significant G2/M arrest and apoptosis in HL-60 cells. The HMJ-38 induced-G2/M arrest occurred before the onset of apoptosis. Within 24 hours of treatment, HMJ-38 affected the CDK/cyclin B activity by increasing Chk1, Wee1 and p21, and decreasing Cdc25c protein levels. The HMJ-38-induced apoptosis was further confirmed by morphological assessment and DNA fragmentation assay. Induction of apoptosis in HMJ-38-treated HL-60 cells was accompanied by an apparent increase of cytosolic cytochrome c, down-regulation of Bcl-2 and survivin, up-regulation of Bax and Bak, and cleavage of Bid, pro-caspase-9, -3, and poly(ADP)ribosylpolymerase (PARP). Results of the significant reduction of caspase activities and apoptosis by caspase inhibitors indicated that the HMJ-38-induced apoptosis was mainly mediated by activation of caspases-9 and -3. HMJ-38 also activated ERK in HL-60 cells. Pre-incubating cells with ERK inhibitors (U0126 and PD98059) attenuated the HMJ-38 induced ERK activation and apoptosis. Nevertheless, cells remained arrested in G2/M. Before performing animal studies, we confirmed that HMJ-38 concentration-dependently decreased viability of WEHI-3 cells with an IC50 of 5.0 M. HMJ-38-induced G2/M arrest companioned by apoptosis was further confirmed by morphological assessment, cell cycle analysis and DNA fragmentation assay. Intravenous injection of WEHI-3 cells in a high number (1X106) into Balb/c mice successfully induced leukemia in these mice 28 days later. HMJ-38 treatment (i.v. of 2.5 mg/kg/2 days for 14 days) started at 14 days after WEHI-3 cell injection. Taxol at a dose of 5 mg/kg/day was used as the positive control for comparison. In animal study, HMJ-38 enhanced survival rate and prevent the body weight loss in leukemia mice within one month of experiment. The enlargement of spleen and lymph nodes and liver metastasis were significantly reduced in HMJ-38 treated groups. H-E stain of spleen sections revealed that infiltration of immature myeloblastic cells into splenic red pulp was reduced in HMJ-38 treated groups. Flow cytometric analysis of leukocyte subtypes in PBMC showed that CD19+ cell population was significantly increased to normal range in HMJ-38- or taxol-treated leukemia mice than that in untreated leukemia mice. In contrast, the CD14+ and Mac-3+ cell populations in the HMJ-38 treated leukemia Balb/c mice were significantly reduced to normal range than those in untreated group. These results suggest that HMJ-38 is a potent anticancer drug. It shows a remarkable action on cell cycle before commitment for apoptosis is reached. In addition, HMJ-38 demonstrates prominent anti-cancer activity in WEHI-3/Balb/c leukemia model.

Ce mémoire s’est attaché à comprendre les dimensions émergentes de la constitution de l’image d’une organisation. A l’issue de l’étude de la littérature de recherche existante, nous nous sommes intéressée à l’image réfractée, qui est l’image d’une organisation construite par une catégorie de publics nommés arbitres externes. Ce sont les organisations mandatées qui diffusent de l’information au grand public. En adoptant l’approche qualitative, nous avons réalisé une étude du processus de travail des journalistes travaillant pour des journaux différents et des membres des organismes environnementaux dans le cas de la mise en œuvre du projet de loi C-38 du gouvernement fédéral canadien. L’étude empirique nous a permis de proposer un modèle conceptuel du phénomène de la construction de l’image réfractée. Nous avons pu ainsi suggérer d’observer ce phénomène à travers les pratiques de travail des acteurs pour appréhender les dynamiques d’émergence de l’image. Aussi, nous avons insisté sur la pertinence de considérer des paramètres qui constituent le cadre dans lequel se déroule le processus de travail des acteurs appartenant à des communautés de publics différentes. Car ce sont ces paramètres qui engendrent des dynamiques régulant la construction de l’image organisationnelle au sein de chaque communauté de public.
Our research aimed to understand the emergent dimensions of an organization’s image construction. Following the review of existing research literature, we are interested in the refracted image, which is the image of an organization built by a specific public named external arbiters. These external arbiters are mandated organizations that disseminate information to the general public. By adopting a qualitative approach, we conducted a study about the case of the implementation of Bill C-38 by the Canadian Federal Government. Specifically, we examined the working process of two arbiters communities : journalists working for different newspapers, and environmental organizations’ members. The empirical study has allowed us to propose a conceptual model of the construction of the refracted image phenomenon. We thus suggested to observe this phenomenon through the actors’ working practices to understand the emergence of the image dynamics. Also, we emphasized the relevance to consider factors that constitute the framework within which the working process of the actors belonging to different public communities takes place. For it is these parameters that generate the various dynamics regulating the organizational image’s construction by each public community.

Ce travail étudie les systèmes "pouzzolanes naturelles-chaux-eau" à 38 et 100°C afin de comprendre les phénomènes physicochimiques caractérisant la pouzzolanicité des matériaux naturels. La mise en évidence de nouveaux critères physicochimiques corrélant la minéralogie des produits d'hydratation, les qualités mécaniques des mélanges "pouzzolanes-chaux-eau" nous permet de proposer une nouvelle classification des matériaux pouzzolaniques. Cette classification repose sur: - une caractérisation et une quantification des constituants réactifs (les verres volcaniques non rhyolitiques, les opales, les zéolites), - une étude des solides néoformés et des solutions issus de l'essai Chapelle (16h à 100°C dans une solution saturée de chaux), - une étude minéralogique et morphologique des phases cristallines néoformées, issues du système "pouzzolanes-cllaux-eau" à 38°, constituant la matrice des pâtes durcies. L'ensemble de ces observations montre que les silices sédimentaires, les roches volcaniques et l'alumine activée constituent une série homologue discontinue à 38 et 100°C dans le système "CaO-. AI203-S102-H20". Ces matériaux s'illustrent par la coéxistence entre la fraction siliceuse de la solution solide des hydrogrenats et des gels silicocalciques hydratés (partiellement alumineux) à 100°C, et la coéxistence entre la solution solide des silicoaluminates tétracalciques hydratés et les gels silicocalciques hydratés.