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This work is devoted to understanding the formation of supported lipid bilayers (SLBs) on curved surfaces as a function of lipid properties such as headgroup charge/charge density and alkyl chain length, and nanoparticle properties such as size and surface characteristics. In particular, the formation of SLBs on curved surfaces was studied by varying the size of the underlying substrate SiO2 nanoparticles with size range from 5-100 nm. Curvature-dependent shift in the phase transition behavior of these supported lipid bilayers was observed for the first time. We found that the phase transition temperature, Tm of the SLBs first decreased with decreasing the size of the underlying support, reached a minimum, and then increased when the size of the particles became comparable with the dimensions of the lipid bilayer thickness; the Tm was above that of the multilamellar vesicles (MLVs) of the same lipids. The increase in Tm indicated a stiffening of the supported bilayer, which was confirmed by Raman spectroscopic data. Moreover, Raman data showed better lipid packing and increased lateral order and trans conformation for the SLBs with increasing the curvature of the underlying support and decrease of the gauche kinks for the terminal methyl groups at the center of the bilayer. These results were consistent with a model in which the high free volume and increased outer headgroup spacing of lipids on highly curved surfaces induced interdigitation in the supported lipids. These results also support the symmetric lipid exchange studies of the SLBs as a function of the curvature, which was found to be slower on surfaces with higher curvature. Further, the effect of surface properties on the formation of SLBs was studied by changing the silanol density on the surface of SiO2 via thermal/chemical treatment and monitoring fusion of zwitterionic lipids onto silica (SiO2) nanoparticles. Our findings showed that the formation of SLBs was faster on the surfaces with lower silanol density and concomitantly less bound water compared to surfaces with higher silanol density and more bound water. Since the two SiO2 nanoparticles were similar in other respects, in particular their size and charge (ionization), as determined by zeta potential measurements, differences in electrostatic interactions between the neutral DMPC and SiO2 could not account for the difference. Therefore the slower rate of SLB formation of DMPC onto SiO2 nanoparticles with higher silanol densities and more bound water was attributed to greater hydration repulsion of the more hydrated nanoparticles. Lastly, we have investigated the effect and modulation of the surface charge of vesicles on the formation of SLBs by using different ratios of zwitterionic and cationic DMPC/DMTAP lipids. Through these studies we discovered a procedure by which assemblies of supported lipid bilayer nanoparticles, composed of DMPC/DMTAP (50/50) lipids on SiO2, can be collected and released from bilayer sacks as a function of the phase transition of these lipids. The lipids in these sacks and SLBs could be exchanged by lipids with lower Tm via lipid transfer. / Chemistry

Text in Afrikaans / Die eng definiering van kerkmusiek staan tans in die spervuur vanwee: 1. Ingrypende wendinge binne die praktiese teologie in die afgelope paar dekades, wat pleit om 'n hernieude ondersoek binne die handelingsveld van viering (waaronder himnologie); 2. 'n Verskuiwing in wereldbeskouing weg van modernisme na postmodernisme; 3. Die geboorte van 'n totaal nuwe geslag adolessente, bekend as die 'Verlore Generasie' of 'Generasie X' . Kerkmusiek, in die engere sin, soos dit steeds grootliks verstaan word, hou nie genoegsaam met hierdie tendense rekening nie. Vandaar verloor kerkmusiek sy impak en inspraak in die leefwereld van die hedendaagse tiener. Dit veroorsaak gevolglik 'n groterwordende kloof tussen adolessente en die erediens, gemeente en kerk. In hierdie studie word gepoog om genoegsaam op bostaande tendense ag te slaan, sodat 'n breer def iniering van kerkmusiek tot stand mag kom, wat ruimte vir grater verskeidenheid en aktualiteit tot gevolg sal he, en die spanning random kerkmusiek en die tiener kan probeer ontlont. / The narrow defining of church music today experiences a critical assault on account of: 1. Drastic turns within the development of Practical theology in the past few decades, which ask for a renewed investigation within the field of himnology; 2. a Shift in worldview away from modernism to post-modernism; 3. The birth of a total new generation of adolescents, known as the 'Lost Generation' or 'Generation X' . Church music in the narrow sense, as it is still understood to a great extent, does not take these tendencys serious enough. For this reason it's impact and influence in the life of today's teenagers declines. With this study a thorough acknowledgement of these shifts is attempted, which will result in a much broader defining of church music, and in turn will bring forth a scope for more variety and actuality, so that hopefully the growing gap between teenagers and church music can be bridged. / Practical Theology / M.Diac. (Jeugwerk)

This thesis addresses the problem of the lack of a systematic approach to the modernisation of the indigenous languages of South Africa, with particular reference to Venda. Thus, a systematic approach is proposed in this study for the development of modem terminology in Venda. This approach is based on the canonical model for language planning. In this model, terminology development should follow the following four steps: (1) analysis of the terminological needs of the situation, (2) preparation of a plan and strategies for research, (3) implementation of terminology in practice by means of suitable policies, and lastly, (4) evaluation and constant updating of terminology. Within the canonical model for language planning, different models or frameworks are proposed. First is the theoretical model, which follows the pragmatic approach rather than a purist approach and takes into consideration other extralinguistic factors such as the nature of the special subject field, the needs of the target users and the socio-cultural context. The pragmatic approach is divided into two phases, namely the borrowing phase and the indigenisation phase. In the borrowing phase the borrowed terms are incorporated into the language with immediate effect and these terms may be replaced by indigenous terms in the indigenisation phase where less specialised communication is used. In the indigenisation phase, different language internal term formation strategies were identified, namely semantic shift, derivation, compounding, paraphrasing, initialisms, acronyms, clipping and new word manufacture. It was established that the use of these term formation strategies in Venda requires linguistic expertise, technical expertise and cultural expertise. Accordingly, a sociolinguistic approach is recommended rather than a purely linguistic approach. Lastly, a model of practical terminology work and a model for cooperation and coordination are proposed for terminology work in this language. With regard to the former, various steps that should be followed in terminology work are outlined. In the latter model various language agencies, such as government departments, parastatals and non-governmental organisations that may be involved in the modernisation of this language are identified. A framework in which these agencies could cooperate and coordinate their terminology work is proposed. / Linguistics / D.Litt. et Phil. (Linguistics)

Progress towards sustainability requires changes in our individual and collective behaviour. Yet, our fundamental understanding of behaviour in relation to environmental change remains severely limited. In particular, little attention has been given to how individual and collective behaviours respond to, and are shaped by, non-linear environmental change (such as ‘regime shifts’) and its inherent uncertainties. The thesis makes two main contributions to the literature: 1) it provides one of the first accounts of human behaviour and collective action in relation to ecological regime shifts and associated uncertainties; and 2) extends the incipient behavioural common-pool resource literature that acknowledges social-ecological dynamics and ecological complexity. The overarching aim of this thesis is to further advance an empirically grounded understanding of human behaviour in social-ecological systems. In particular, the thesis attempts to unravel critical social-ecological factors and mechanisms for the sustainability of common-pool resources. This is especially relevant for contexts in which livelihoods can be more directly threatened by regime shifts. The following methods are applied: behavioural economic experiments in the lab (with students; Papers I and II) and in the field (with small-scale fishers from four different communities in the Colombian Caribbean; Paper III), and agent-based modelling empirically informed by a subset of the lab experiments (Paper IV). Paper I tests the effect of an endogenously driven regime shift on the emergence of cooperation and sustainable resource use. Paper II tests the effect of different risk levels of such a regime shift. The regime shift in both papers has negative consequences for the productivity of the shared resource. Paper III assesses the effect of different degrees of uncertainty about a climate-induced threshold in stock dynamics on the exploitation patterns; as well as the role of social and ecological local context. Paper IV explores critical individual-level factors and processes affecting the simultaneous emergence of collective action and sustainable resource use. Results cumulatively suggest that existing scientific knowledge indicating the potential for ecological regime shifts should be communicated to affected local communities, including the remaining uncertainties, as this information can encourage collective action for sustainable resource use. Results also highlight the critical role of ecological knowledge, knowledge-sharing, perceived ecological uncertainties, and the role local contexts play for sustainable outcomes. This thesis enriches the literature on social-ecological systems by demonstrating how a behavioural experimental approach can contribute new insights relevant for sustainability. Overall, these insights indicate that, given the opportunity and the willingness of people to come together, share knowledge, exchange ideas, and build trust, potential ecological crises can encourage collective action, and uncertainties can be turned into opportunities for dealing with change in constructive ways. This provides a hopeful outlook in the face of escalating environmental change and inherent uncertainties. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>

The thesis analyses selected phenomena of graphy, phonology, morfology, lexicology and words-formation of the Frederick from Donin's Czech book of travels, which was written at the turn of the 16th and 17th century. Partly, it also deals with the syntax and style of the work. Selected phenomena of individual language levels are studied using the original manuscript. The thesis intends to show in which aspects the text is close to early modern language usage, and conversely in which aspects it differs from it. The language of the manuscript is also compared with the contemporary Czech language.

(in English): The work in this diploma contains the special syntactic structural features of Russian and Czech historical and political science texts. The author of the work takes as a theoretical starting point the principle that Russian scientific texts use more condensed forms of expression than Czech scientific texts, and uses evidence in this diploma to verify the truth of this principle. Quantitative research was carried out to test this theory via examination of Czech and Russian historical and political science texts in both original and translated forms. The original criteria for the choice of texts used was thematic closeness, time period of text creation and a minimum length of 5,000 words. This criteria was later expanded to 7,000 words for original texts and 9,000 words for original texts and their translations. In addition to this a translation analysis was carried out concerning condensation devices, expression dynamics and the implicitness and explicitness of the text. The contrastive analysis of applied condensation devices of Czech and Russian texts adheres to the classification framework of Czech linguist Milan Jelinek. The results of the author's analysis confirm that Russian political science and historical texts reach higher predicative tightness of expression and use more...

Cette thèse est centralisée sur cette question : comment est-ce que le système visuel peut coder efficacement la position des objets en mouvement, en dépit des diverses sources d'incertitude ? Cette étude déploie une hypothèse sur la connaissance a priori de la cohérence temporelle du mouvement (Burgi et al 2000; Yuille and Grzywacz 1989). Nous avons ici étendu le cadre de modélisation précédemment proposé pour expliquer le problème de l'ouverture (Perrinet and Masson, 2012). C'est un cadre d'estimation de mouvement Bayésien mis en oeuvre par un filtrage particulaire, que l'on appelle la prévision basé sur le mouvement (MBP). Sur cette base, nous avons introduit une théorie du codage de position basée sur le mouvement, et étudié comment les mécanismes neuronaux codant la position instantanée de l'objet en mouvement pourraient être affectés par le signal de mouvement le long d'une trajectoire. Les résultats de cette thèse suggèrent que le codage de la position basé sur le mouvement peut constituer un calcul neuronal générique parmi toutes les étapes du système visuel. Cela peut en partie compenser les effets cumulatifs des délais neuronaux dans le codage de la position. En outre, il peut expliquer des changements de position basés sur le mouvement, comme par example, l'Effect de Saut de Flash. Comme un cas particulier, nous avons introduit le modèle de MBP diagonal et avons reproduit la réponse anticipée de populations de neurones dans l'aire cortical V1. Nos résultats indiquent qu'un codage en position efficace et robuste peut être fortement dépendant de l'intégration le long de la trajectoire. / Coding the position of moving objects is an essential ability of the visual system in fulfilling precise and robust tracking tasks. This thesis is focalized upon this question: How does the visual system efficiently encode the position of moving objects, despite various sources of uncertainty? This study deploys the hypothesis that the visual systems uses prior knowledge on the temporal coherency of motion (Burgi et al 2000; Yuille and Grzywacz 1989). We implemented this prior by extending the modeling framework previously proposed to explain the aperture problem (Perrinet and Masson, 2012), so-called motion-based prediction (MBP). This model is a Bayesian motion estimation framework implemented by particle filtering. Based on that, we have introduced a theory on motion-based position coding, to investigate how neural mechanisms encoding the instantaneous position of moving objects might be affected by motion. Results of this thesis suggest that motion-based position coding might be a generic neural computation among all stages of the visual system. This mechanism might partially compensate the accumulative and restrictive effects of neural delays in position coding. Also it may account for motion-based position shifts as the flash lag effect. As a specific case, results of diagonal MBP model reproduced the anticipatory response of neural populations in the primary visual cortex of macaque monkey. Our results imply that an efficient and robust position coding might be highly dependent on trajectory integration and that it constitutes a key neural signature to study the more general problem of predictive coding in sensory areas.