Il est couramment admis que la déformation plastique des phases MAX est dueau glissement de dislocations dans les plans de base s'organisant en empilements et murs. Cesderniers peuvent former des zones de désorientation locale appelées kink bands. Cependant, lesmécanismes élémentaires et le rôle exact des défauts microstructuraux sont encore mal connus. Cemanuscrit présente une étude expérimentale multi-échelle des mécanismes de déformation de laphase MAX Ti2AlN. A l'échelle macroscopique, deux types d'expériences ont été menés. Des essaisde compression in-situ à température et pression ambiantes couplés à la diffraction neutroniqueont permis de mieux comprendre le comportement des différentes familles de grains dans le Ti2AlNpolycristallin. Des essais de compression sous pression de confinement ont également été réalisés dela température ambiante jusqu'à 900 °C. À l'échelle mésoscopique, les microstructures des surfacesdéformées ont été observées par MEB et AFM. Ces observations complétées par des essais denanoindentation ont montré que la forme des grains et leur orientation par rapport à la directionde sollicitation gouvernent l'apparition de déformations intra- et inter-granulaires ainsi que lalocalisation de la plasticité. Finalement à l'échelle microscopique, une étude détaillée par METdes échantillons déformés sous pression de confinement a révélé la présence de configurations dedislocations inédites dans les phases MAX, telles que des réactions entre dislocations, des dipôleset des dislocations hors plan de base. À la vue de ces résultats nouveaux, les propriétés mécaniquesdes phases MAX sont rediscutées. / It is commonly believed that plastic deformation mechanisms of MAX phases consistin basal dislocation glide, thus forming pile-ups and walls. The latter can form local disorientationareas, known as kink bands. Nevertheless, the elementary mechanisms and the exact role ofmicrostructural defects are not fully understood yet. This thesis report presents a multi-scale experimentalstudy of deformation mechanisms of the Ti2AlN MAX phase. At the macroscopic scale,two kinds of experiments were performed. In-situ compression tests at room temperature coupledwith neutron diffraction brought new insight into the deformation behavior of the different grainfamilies in the polycrystalline Ti2AlN. Compression tests from the room temperature to 900 °Cunder confining pressure were also performed. At the mesoscopic scale, deformed surface microstructureswere observed by SEM and AFM. These observations associated with nanoindentationtests showed that grain shape and orientation relative to the stress direction control formationof intra- and inter- granular strains and plasticity localization. Finally, at the microscopic scale,a detailed dislocation study of samples deformed under confining pressure revealed the presenceof dislocation configurations never observed before in MAX phases, such as dislocation reactions,dislocation dipoles and out-of-basal plane dislocations. In the light of these new results, mechanicalproperties of MAX phases are discussed.

<p>Lung cancer is the third most prevalent cancer in the world; however it is the leading cause of cancer related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for ~85% of the lung cancer cases. The current strategies to treat NSCLC patients with frequent causal genetic mutations is through targeted therapeutics. Approximately 10-35% of NSCLC patient tumors have activated mutations in the Epidermal Growth Factor Receptor (EGFR) resulting in uncontrolled cellular proliferation. The standard-of care for such patients is EGFR-Tyrosine Kinase Inhibitors (EGFR-TKIs), a class of targeted therapeutics that specifically inhibit EGFR activity. One such EGFR-TKI used in this study is erlotinib. Following erlotinib treatment, tumors rapidly regress at first; however, over 50% of patients develop erlotinib resistance within a year post treatment. Development of resistance remains to be the major challenge in treatment of NSCLC using EGFR-TKIs such as erlotinib. </p> <p>In approximately 60% of cases, acquired erlotinib resistance in patients is attributed to a secondary mutation in EGFR, whereas in about 20% of cases, activation of alternative signaling pathways is the reported mechanism. For the remaining 15-20% of <a>cases</a> the mechanism of resistance remains unknown. Therefore, it can be speculated that the common methods used to identify genetic mutations in tumors post erlotinib treatment, such as histologic analysis and genetic screening may fail to identify alterations in epigenetic mediators of erlotinib resistance, also including microRNAs (miRNAs). MiRNAs are short non-coding RNAs that post-transcriptionally negatively regulate their target transcripts. Hence, in this study two comprehensive screens were simultaneously conducted in erlotinib sensitive cells: 1) a genome-wide knock-out screen, conducted with the hypothesis that loss of function of certain genes drive erlotinib resistance, 2) a miRNA overexpression screen, conducted with the hypothesis that certain miRNAs drive the development of erlotinib resistance when overexpressed. The overreaching goal of the study was to identify novel drivers of erlotinib resistance such as microRNAs or other epigenetic factors in NSCLC.</p><p>The findings of this study led to the identification of a tumor suppressive protein and an epigenetic regulator, SUV420H2 (KMT5C) that has never been reported to be involved in erlotinib resistance. On the other hand, the miRNA overexpression screen identified five miRNAs that contribute to erlotinib resistance that were extensively analyzed using multiple bioinformatic tools. It was predicted that the miRNAs mediate erlotinib resistance via multiple pathways, owing to the ability of each miRNA to target multiple transcripts via partial complementarity. Importantly, a correlation between the two screens was identified clearly supporting the use of two simultaneous screens as a reliable technique to determine highly significant miRNA-target interactions. Overall, the findings from this study suggest that epigenetic factors, such as histone modifiers and miRNAs function as critical mediators of erlotinib resistance, possibly belonging to the 15-20% of NSCLC cases with unidentified mechanisms involved in erlotinib resistance.</p><p></p>

Au cours de ce travail, nous avons étudié deux types de défauts interfaciaux: domaines d’inversion (DI) et joints de grains (JG) dans des semiconducteurs de structure wurtzite (nitrures- d’éléments III, ZnO et l’hétérostructure ZnO/GaN) en utilisant le MET haute résolution et la modélisation ab initio. Dans le cas des DI, nos analyses théoriques montrent qu'une configuration tête-à-tête avec une séquence d'empilement à l’interface AaBbAa-AcCaA (H4) est la structure la plus stable dans les composés binaires (nitrures et ZnO wurtzites). De plus, un gaz d’électrons (2DEG) ou de trous (2DHG) à 2 dimensions est formé pour les configurations « tête-à-tête » ou queue-à-queue. A l’interface ZnO/GaN, l'observation de MET très haute résolution a confirmé la configuration H4 avec une interface -Zn-O-Ga-N. Notre modélisation théorique a mis en évidence la formation d’un gas de trous à 2 dimensions à cette hétérointerface. Nous avons aussi réalisé l’étude topologique, théorique et par MET des joints de grains de rotation autour de l’axe [0001] dans ces matériaux. Dans le GaN, nous avons trouvé que les plans du joint sont simplement formés par des dislocations de type a déjà connues pour le matériau en couche mince. Par contre, dans ZnO, la théorie topologique est complétement démontrée, et la dislocation [101 ̅0] est une brique de base dans la constitution des joints de grains avec des cycles d’atomes 6-8-4-. / In this work, we investigated two kinds of interfacial defects: inversion domain boundaries (IDBs) and grain boundaries (GB) in wurtzite semiconductors (III-nitrides, ZnO and ZnO/GaN heterostructure) using high-resolution TEM and first-principle calculations. For IDBs, theoretical calculation indicated that a head-to-head IDB with an interfacial stacking sequence of AaBbAa-AcCaA (H4) is the most stable structure in wurtzite compounds. Moreover, 2-dimensional electron gas (2DEG) and 2-dimensional hole gas (2DHG) build up in head-to-head and tail-to-tail IDBs, respectively. Considering the IDB at the ZnO/GaN heterointerface, TEM observations unveiled the H4 configuration with a -Zn-O-Ga-N interface. Moreover the theoretical investigation also confirmed stability of this interface along with the corresponding formation of a 2DHG. A detailed topological, TEM and theoretical investigation of [0001] tilt Grain Boundaries (GBs) in wurtzite symmetry has also been carried out. In GaN, it is shown that the GBs are only made of separated a edge dislocations with 4, 5/7 and 8 atoms rings. For ZnO, a new structural unit: the [101 ̅0] edge dislocation made of connected 6-8-4-atom rings is reported for the first time, in agreement with an early theoretical report on dislocations and jogs in the wurtzite symmetry.

The research dealt with the influence that gestalt group therapy may have on the emotional development of deprived toddlers. The research consisted of a literature study and an empirical study. The literature study contains information on groupwork and emotional development of the toddler. The empirical research was conducted by involving six toddlers in a group. They were identified by means of purposive sampling. A pre-test was done with each child to determine their emotional development. After six group sessions of 30 minutes each, a post-test (using the same test as for the pre-test) was done with each child. The pre-test and post-test results were compared with each other. The content of each session were examined and also included in the findings. Empirical data revealed that gestalt group therapy can stimulate the emotional development of deprived toddlers. The conclusion can thus be made that gestalt group therapy can stimulate the emotional development of deprived toddlers. As a result of this study, conclusions and recommendations for future research were formulated. AFRIKAANS : Die ondersoek was daarop gerig om te bepaal of die benutting van gestaltgroepspelterapie die emosionele ontwikkeling van die gedepriveerde kleuter kan stimuleer. Die ondersoek het bestaan uit 'n literatuurstudie sowel as empiriese navorsing. Die literatuurstudie is gedoen ten opsigte van groepwerk en die kleuter se emosionele ontwikDie empiriese deel van die ondersoek is uitgevoer deur ses kleuters deur middel van doelgerigte steekproeftrekking by die groep in te sluit. 'n Voortoets om die emosionele ontwikkeling van die kleuters te bepaal, is gedoen. Daarna is ses gestaltgroepwerksessies van 30 minute elk uitgevoer. Dieselfde toets as wat vir die voortoets benut is, is weer aan die kleuters gegee en die resultate is met mekaar vergelyk. Die inligting uit die sessies is ook genoteer en benut. Uit die empiriese gegewens het dit geblyk dat daar wel emosionele ontwikkeling by die kleuters plaasgevind het. Die gevolgtrekking kan dus gemaak word dat gestaltgroepspelterapie benut kan word om gedepriveerde kleuters se emosionele ontwikkeling te stimuleer. Gevolgtrekkings en aanbevelings vir toekomstige navorsing is na aanleiding van die studie geformuleer. keling. Copyright / Dissertation (MSW)--University of Pretoria, 2009. / Social Work and Criminology / unrestricted

This dissertation explores factors that play a role in students' decisions to attend one Northern California Early College High School (NCECHS). It also examines how students perceive their experiences of their decision after they have enrolled. The history of the public education has long been marked by an achievement gap between White and Asian students and students from other ethnic groups. In spite of efforts to address this issue, the gap continues to widen. Early College High Schools (ECHS's) are examples of reform models that are developed to support student achievement among undeserved groups. Without an understanding of the factors that influence student decisions to attend ECHS's and an understanding of the ways students perceive their experiences in such schools; administrators and teachers in these schools are left to more or less "guess" at the most effective ways to structure curriculum and instruction. A qualitative analysis was used to explore student perception and experiences. A survey asked students to share the primary factors that influenced their decision to attend NCECHS, instead of a traditional public school. Findings from this research suggest that the participant's perceived costs and benefits were based on both personal preferences and rational choices. Some aspects of the program that were especially pleasing to students included having the opportunity to earn a high school diploma, earn college credit and earn an associate's degree at the same time. Many students expressed dissatisfaction and anxiety with attending this ECHS. Frustration with the college enrollment process, prerequisites, heavy workloads, time management, fear of academic failure, relationships with instructors and disassociation from friends were also among the findings of this study.

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advancements in Old Testament and New Testament Studies. For example, new knowledge is available on the variant versions of the Septuagint and application of the literary concept of intertextuality has yielded significant results in recent biblical scholarship. However, considering that 1 Peter arguably uses the Old Testament in the most condensed manner of all the New Testament writings, it is surprising that relatively few recent studies have been carried out on the use of the Old Testament in 1 Peter. As a partial corrective to this situation, this in-depth study is focused on the use of the Psalms in 1 Peter, utilizing an integrated hermeneutical procedure that combines traditional grammatical-historical analysis with the state of the art on New Testament use of the Old Testament. The aim is to clarify the hermeneutical implications of the use of the Psalms in 1 Peter for Old Testament and New Testament exegesis within the Reformed tradition today. Thus, a comprehensive exegetical approach is systematically applied to each pericope of 1 Peter and to every relevant Psalm passage in order to establish a valid foundation for understanding how the author interprets the Psalms and how the Psalm references function within the argument of 1 Peter. In addition, intertextual resonance is considered as an effective means to enhance understanding of the function and effect of Psalm references as intended by the author, and to determine the possible unintended effect of Psalm references upon the addressees and later readers. Furthermore, consideration of reader response sometimes makes it possible to identify echoes of Psalm passages not likely intended by the author, but nevertheless, very likely to have come to the minds of the recipients with significant effect. One conclusion of this study is that there is no compelling evidence that the author’s interpretation of the Psalms ignored the intended meaning of the Psalm in its own context, or merely reflected contemporary Second Temple interpretations. Furthermore, it has been possible to refine the criteria for identifying and classifying Psalm allusions rather than merely following broad, predetermined criteria. Thus, a distinction is made between specific allusion, in which case the author’s argument depends upon recognition of specific Psalm passages, and general allusion, in which case the author’s argument depends upon a concept recognizably derived from the Psalms but not limited by the wording of specific references. This study also demonstrates that the use of the Psalms in 1 Peter is based upon a strong sense of solidarity with believers of the past, especially as they expressed their responses to God in the context of suffering. In particular, compared with other New Testament writings, 1 Peter stands out for the fact that the majority of its Psalm allusions are used for the purpose of developing and reapplying significant themes. Thus, 1 Peter provides compelling reason for present-day interpreters to view theme development as a valid and effective way to apply the Psalms to the circumstances of Christian believers as they face the challenge of living faithfully in new contexts of suffering and persecution. / PhD (New Testament), North-West University, Potchefstroom Campus, 2014

advancements in Old Testament and New Testament Studies. For example, new knowledge is available on the variant versions of the Septuagint and application of the literary concept of intertextuality has yielded significant results in recent biblical scholarship. However, considering that 1 Peter arguably uses the Old Testament in the most condensed manner of all the New Testament writings, it is surprising that relatively few recent studies have been carried out on the use of the Old Testament in 1 Peter. As a partial corrective to this situation, this in-depth study is focused on the use of the Psalms in 1 Peter, utilizing an integrated hermeneutical procedure that combines traditional grammatical-historical analysis with the state of the art on New Testament use of the Old Testament. The aim is to clarify the hermeneutical implications of the use of the Psalms in 1 Peter for Old Testament and New Testament exegesis within the Reformed tradition today. Thus, a comprehensive exegetical approach is systematically applied to each pericope of 1 Peter and to every relevant Psalm passage in order to establish a valid foundation for understanding how the author interprets the Psalms and how the Psalm references function within the argument of 1 Peter. In addition, intertextual resonance is considered as an effective means to enhance understanding of the function and effect of Psalm references as intended by the author, and to determine the possible unintended effect of Psalm references upon the addressees and later readers. Furthermore, consideration of reader response sometimes makes it possible to identify echoes of Psalm passages not likely intended by the author, but nevertheless, very likely to have come to the minds of the recipients with significant effect. One conclusion of this study is that there is no compelling evidence that the author’s interpretation of the Psalms ignored the intended meaning of the Psalm in its own context, or merely reflected contemporary Second Temple interpretations. Furthermore, it has been possible to refine the criteria for identifying and classifying Psalm allusions rather than merely following broad, predetermined criteria. Thus, a distinction is made between specific allusion, in which case the author’s argument depends upon recognition of specific Psalm passages, and general allusion, in which case the author’s argument depends upon a concept recognizably derived from the Psalms but not limited by the wording of specific references. This study also demonstrates that the use of the Psalms in 1 Peter is based upon a strong sense of solidarity with believers of the past, especially as they expressed their responses to God in the context of suffering. In particular, compared with other New Testament writings, 1 Peter stands out for the fact that the majority of its Psalm allusions are used for the purpose of developing and reapplying significant themes. Thus, 1 Peter provides compelling reason for present-day interpreters to view theme development as a valid and effective way to apply the Psalms to the circumstances of Christian believers as they face the challenge of living faithfully in new contexts of suffering and persecution. / PhD (New Testament), North-West University, Potchefstroom Campus, 2014

Those who take the Great Commission of Christ seriously realise that enlarging today's mission force is crucial. The Two-thirds World church is in a prime position to meet the need. Cross-cultural mission training would greatly enhance and accelerate the fulfilling of Christ's final mandate to the Church. As founding director of Missions Exposure and Training (MET), a Christian ministry located in Pretoria, South Africa, the author of the thesis lays out the details of the programme for the reader. MET is the case study being considered, with particular emphasis placed on Missionary Candidate School (MCS), the backbone of MET. Before MET is introduced, the thesis begins with the challenge facing the universal Church today: the need to strengthen and enlarge the current mission force. The theological implications of Jesus Christ's mandate to the Church, the missionary purpose of the Church, as well as eschatological concerns build a strong argument for the need of a larger mission force. Demographic changes taking place within the Church mean that Two-thirds World Christians should be considered as a primary resource for cross-cultural mission endeavours. To maximise the potential of the new recruits, which the writer refers to as 'missionary candidates,' further discussion is given for the need of systematic training and equipping of Two-thirds World missionaries. After describing MET and MCS, the programme is critically evaluated. MCS is proven to be effective in training African men and women for intercultural Christian mission service, and as such it becomes a model worth investigating. The clear findings that result from the candid evaluation, and assessments made in light of current theological and missiological issues, should prove to be beneficial to those developing programmes with the purpose of training and equipping Two-thirds World missionaries. / Christian Spirituality, Church History and Missiology / D. Th. (Missiology)