Imagining success, experiencing social injustices and learner poor performance.

Doctoral Degree. University of KwaZulu-Natal, Durban.The attainment of academic success is something to which most learners aspire. Sadly, many, and in particular learners from disadvantaged backgrounds tend to fall short of achieving such aspirations. This is especially the case when their achievements are measured against the academic rigour of their wealthier and certainly more advantaged counterparts. To ask marginalised learners to reflect on the attainment of academic success may therefore be unreasonable and impractical. It is for this reason, amongst others, that the notion of simply imagining success was pertinent in my study. My study takes place against the backdrop of increasing instances of inequality both locally and globally. The site in which my study was based was in a historically “coloured” community in which the adverse effects of social injustice are an everyday reality for many who live and school within this community. The effects of inequality are clearly reflected in the everyday experiences of learners within schools. For instance, having to learn in environments that are neither welcoming nor conducive to the attainment of academic success are but some of the experiences that were commonplace in the lives of the twelve learners who participated in my study. Positioned firmly within the discipline of social justice and employing a critical methodological approach, my study aimed to give voice to these twelve learners who have too often been silenced so as to serve the benefits of social groups who are already in positions of power. I thus attempted to answer questions which illuminate what the unique experiences of these learners were concerning instances of social injustice as well as how these experiences may or may not have influenced their imaginings of success, and ultimately their academic performance. From an axiological perspective, the realities of the twelve learners in my study were brought to the fore as I chose to dedicate a large portion of my study to both their spoken and written words surrounding their experiences of social injustices, their academic performance, and indeed their imaginings of success. With an immense focus on the phenomenon of learners’ imaginings, I relied heavily on the work of Gilles Deleuze to frame my study. However, remaining true to the critical theory paradigm and the discipline of social justice, I also turned to the writings of Paulo Freire. This enabled me to not merely research, but to also bring about change in the lives of the learners who participated in my study, albeit change which existed only in their minds. The use of photo elicitations, the writing of imaginative narratives, individual interviews as well as a focus group interview served as the means by which data was collected. Learners were thus given a diverse array of methods through which to communicate their experiences and imaginings. Upon analysing the data, some of the findings which emerged suggested that learners are constantly exposed to low expectations and the doctoring of results; learners learn in environments of fear where their paths to success are often blocked; learners learn in spaces which represent unequal power relations; learners do have imaginings of success but they are influenced by exposure to social injustices in their school, and finally; learners have the potential to transcend their circumstances through their imaginings of success. Ultimately these findings as well as the theories of both Deleuze and Freire resulted in my developing what I called “the elliptic theory of imagination.” True to its name, this theory demonstrated that while learners are able to eventually transcend their circumstances with the help of imagination, learners’ imaginings nevertheless followed an elliptical orbit around their material realities. At times learners’ imaginings were too close to their realities and were therefore limited by them. While at others, learners’ imaginings were too far afield from their realities and were thus unrealistic. Essentially, an implication of my study was that in order for imagination to operate as a vehicle for liberation, learners’ imaginings must exist within an area of orbit which I called “the lavender zone.” This zone is neither too close to, nor too far from one’s material reality. Therefore, in this zone imagination was neither limited by experiences nor so far removed from reality that it became unrealistic

Long-range interactions in the effective low energy Hamiltonian of Sr2IrO4: a core level resonant inelastic x-ray scattering study

We have investigated the electronic structure of Sr2IrO4 using core level resonant inelastic x-ray scattering. The experimental spectra can be well reproduced using ab initio density functional theory based multiplet ligand field theory calculations, thereby validating these calculations. We found that the low-energy, effective Ir t2g orbitals are practically degenerate in energy. We uncovered that covalency in Sr2IrO4, and generally in iridates, is very large with substantial oxygen ligand hole character in the Ir t2g Wannier orbitals. This has far reaching consequences, as not only the onsite crystal-field energies are determined by the long range crystal-structure, but, more significantly, magnetic exchange interactions will have long range distance dependent anisotropies in the spin direction. These findings set constraints and show pathways for the design of d^5 materials that can host compass-like magnetic interactions

Optimization of ligation of intein constructs for the preparation of segmentally labeled α-actinin-1

α-aktinin-1 je aktin-vezavni protein, ki na območju stresnih vlaknih in fokalnih stikov prečno povezuje aktinske filamente ter jih pripenja na membranske adhezijske komplekse. S tem opravlja pomembno vlogo pri procesu celičnega premikanja. Njegova funkcija povezovanja aktinskih filamentov je negativno regulirana s povišano znotrajcelično koncentracijo kalcija. Vezava kalcijevega iona v kalmodulinu podobno domeno človeškega α-aktinina-1 povzroči konformacijske spremembe, ki vplivajo na dinamiko priležne aktin-vezavne domene (ABD). Natančnejši mehanizem regulacije in z njim povezane konformacijske spremembe še niso pojasnjeni, zato smo želeli okarakterizirati spremembe v dinamiki domene ABD med apo (z vezanim Ca2+-ionom) in holo (brez vezanega Ca2+-iona) oblikama α-aktinina-1 z metodo NMR. Ker je celoten α-aktinin-1 prevelik za preučevanje z NMR, želimo za nadaljnje raziskave pripraviti segmentno označen protein, pri katerem bo izotopsko označena zgolj domena ABD. Pripravo segmentno označenega proteina omogoča ligacija dveh ločeno izraženih fragmentov željenega proteina z metodo trans-spajanja preko razcepljenega inteina. V tem delu smo postavili izhodišče za pripravo segmentno označenega α-aktinina-1. Uspešno smo izolirali inteinska konstrukta z zapisom za fragmenta α-aktinina-1 in ju ligirali z metodo trans-spajanja preko razcepljenega inteina Cfa. Ligacijo inteinskih konstruktov smo optimizirali in pokazali, da je izkoristek ligacije največji pri temperaturi 33 °C. Z ligacijo inteinskih konstruktov v velikemmerilu smo potrdili, da je izkoristek ligacije dovolj velik za pripravo segmentno označenega α-aktinina-1 za meritve NMR.α-actinin-1 is a cytoskeletal actin-binding protein found in stress fibers and focal adhesion sites, where it crosslinks actin filaments and attaches them to membrane junction complexes. Consequently, it plays an important role in cell migration. Its crosslinking function is thought to be negatively regulated by increased intracellular calcium levels. Upon binding of acalcium ion, calmodulin-like domain of human α-actinin-1 undergoes structural changes that also affect the dynamics of juxtaposed ABD domain. The exact mechanism of regulation and consequent conformational changes remain elusive. Therefore, we wish to characterise changes in the dynamics of ABD domain between calcium-free and calcium-bound formsof α-actinin-1 using NMR spectroscopy. Since α-actinin-1 is too large to be successfully analysed by NMR, we wish to prepare segmentally labeled protein where only ABD domain is isotopically labeled. Two separately expressed fragments could be ligated via protein trans-splicing using split inteins to form segmentally labeled protein. In this work we thus set the basis for the preparation of segmentally labeled α-actinin-1. We successfully isolated two intein constructs, each containing a fragment of split α-actinin-1 and ligated them via trans-splicing, using split intein Cfa. We also optimized the ligation of intein constructs and showed that the highest yield is obtained at temperature 33 °C. With a large-scale ligation of intein constructs we confirmed that the yield is high enough for the preparation of segmentally labeled α-actinin-1for NMR studies

The relationship between teachers' conceptions of "globalisation" and professional learning.

Thesis (M.Ed.) - University of KwaZulu-Natal, Edgewood, 2012.At present globalisation has engulfed the world in what has been described as a whirl wind effect, in that is has swirled around the globe and encapsulated it; almost to the extent that the effects of globalisation appear completely inescapable to most nations and citizens. One can assume thus that the influence of globalisation on education, and in particular teacher education, is inevitable. This study focuses on teachers' conceptions of globalisation and its relationship to teacher professional learning with an aim to understand how six teachers exposed to global discourses conceive globalisation and its effect on their professional learning. Given that an effect of globalisation is the merging of various ideas and the exertion of simultaneous influences on such ideas from a variety of sources, a single focus group discussion was used for the generation of dat in this study to produce an environment very similar to the one achieved by globalisation (i.e. an environment in which various ideas are generated simultaneously and are subjected to influences from a variety of sources). From this, rich data emerged highlighting that the teachers in this study have very similar and in some cases very different conceptions of globalisation, teacher professional learning, and the relationship between the two. Interestingly, what stands out is the teachers involved in this study conceive that context, plays an integral role in contemporary teacher learning. The analysis generated theses such as retrogression, inequity, contradictions as well as the experiences of these teachers in learning and not learning. In essence, globalisation and teacher professional learning are shown to be inseparable in this area in which teachers are currently forced to learn for specific contexts and in most cases have to relearn as their contexts change in accordance with the ever evolving nature of globalisation. Indeed teacher professional learning at present is placed under tremendous strain, and so an understanding of the links between globalisation and teacher professional learning is expressed in this study. In addition, what emerges as a plausible solution to the problem of how teacher professional learning may keep up with globalisation, appears to be a need for teachers to take charge of their professional learning and to move away from positions of dependency and passivity to a position of active agency

Photomagnétisme dans les analogues cobalt-fer du bleu de prusse (rôle des espèces du réseau tridimensionnel)

Le photomagnétisme est un axe de recherche en pleine expansion dans le domaine des matériaux inorganiques moléculaires, motivé en partie par les éventuelles perspectives d application pour le stockage de l information. C est dans ce cadre que s inscrit ce travail de thèse. En 1996, l équipe du professeur Hashimoto, à Tokyo, met en évidence un cas de magnétisme photoinduit dans un analogue cobalt-fer du bleu de Prusse. Un transfert d électron photoinduit CoIII(BS)-NC-FeII(BS) CoII(HS)-NC-FeIII(BS) dans des paires diamagnétiques, formées au cours de la synthèse du matériau, est à l origine du gain d aimantation après irradiation, au-dessous de 20 K. Les analogues CoFe du bleu de Prusse restent de bons modèles très intéressants à étudier car ils reproduisent parfaitement la fonction de mémoire des composants traditionnellement utilisés dans l industrie électronique. Pour pouvoir un jour espérer utiliser les analogues CoFe du bleu de Prusse pour stocker une information, il faut impérativement augmenter la température d observation de l effet photomagnétique. Pour cela nous allons chercher à mieux comprendre le rôle joué par les différentes espèces du réseau tridimensionnel dans un analogue photomagnetique de composition chimique Rb2Co4[Fe(CN)6]3,3 11H2O pour but de trouver les conditions chimiques nécessaires pour observer l effet photomagnétique et moduler les propriétés. Les espèces chimiques du réseau 3D sont le ligand cyanure, les espèces composant le réseau tridimensionnel (les ions Co et les entités [Fe(CN)6] et le cation alcalin. La determination du paramètre de champ cristallin des ions Co dans l analogue photo-commutable avant et après irradiation par spectroscopie absorption des rayons X au seuil L2,3 a permis de définir le rôle joué par le ligand cyanure sur les propriétés photomagnétiques. Les études des effets de la substitution/dilution ont permis de comprendre les rôles joués par les espèces Co, les entités [Fe(CN)6] et les cations alcalins sur les propriétés photomagnétiques.One of the challenges in the field of molecular magnetism is the design of optically and thermally switchable magnetic materials for which various kinds of applications may be feasible. The long-known photomagnetic CoFe Prussian blue analogs (PBA) appear to have great potentials for these technological applications. The photomagnetic properties in Co-Fe PBA were evidenced by Hashimoto et al. ten years ago. They are due to a photo-induced electron transfer CoIII(LS)-FeII(LS) CoII(HS)-FeIII(LS). Some significant results concerning the formation of photomagnetic CoIII-FeII pairs and the effect of the amount and nature of inserted alkali-metals on the photomagnetic properties of these compounds have been reported. However the phenomenon is not yet totally understood. In order to understand the switching properties in the Co-Fe Prussian blue analogues, we have studied the role play by each chemical species forming the 3D network in the photomagnetic Prussian blue analogue of chemical formula Rb2Co4[Fe(CN)6]3,3 11H2O. The chemical species forming the 3D network are Co ions, [Fe(CN)6] entities and alkali metal ions. The determination of the Co ligand field parameter in the rubidium compound has allowed the understanding of the role of the cyanide ligand. The effect of the substitutions of the Co, [Fe(CN)6] entities and the alkali metal ions have allowed to understand the role played by these species in the photomagnetic properties.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Structural Rearrangements Induced by Photoexcitation in a RbCoFe Prussian Blue Derivative

International audienceSystems that undergo a reversible and controlled change of their physical properties offer appealing perspectives for the elaboration of electronic devices. Evidence of a photomag- netic effect in a CoFe Prussian blue analogue was a milestone in this research area and showed that molecular excitation can induce long-range magnetic order.[1] In the face-centered cubic structure of the CoFe Prussian blue analogues of chemical formula MxCo4[Fe(CN)6](8+x)/3&(

CoFe Prussian Blue Analogues under Variable Pressure. Evidence of Departure from Cubic Symmetry: X-ray Diffraction and Absorption Study

International audienc