Embora menos eficientes que os vetores virais, lipídios catiônicos têm sido cada vez mais usados como transportadores de material genético. Eles têm como vantagens em relação aos transportadores virais, a baixa imunidade, controle de qualidade e produção em grande quantidade, entre outros. Todavia, a interação entre lipídios catiônicos e material genético ainda é pouco compreendida. No presente trabalho, estudamos a interação entre o anfifílico catiônico brometo de dioctadecildimetilamônio (DODAB) e o nucleotídeo 2´-desoxiadenosina 5´-monofosfato (dAMP). Para tanto, utilizamos a técnica de Ressonância Paramagnética Eletrônica (RPE) aplicada a marcadores de spin derivados do ácido esteárico incorporados em vesículas de DODAB. Os resultados mostraram que na fase gel, na região próxima à superfície das bicamadas de DODAB, o dAMP causa muito pouca alteração na fluidez da membrana, enquanto que, na região do centro da bicamada, o dAMP diminui a fluidez da membrana, o que pode ser um efeito apenas de cargas, isto é, devido à blindagem eletrostática. Já na fase fluida, em ambas as regiões o dAMP aumenta a fluidez da membrana, sendo que, no centro das bicamadas induz um acréscimo significativo na polaridade do meio. A transição de fase gel-fluida do DODAB não sofre modificações com o acréscimo de dAMP. De uma maneira geral, nossos resultados mostraram que o dAMP não causa grandes modificações na estrutura do DODAB. Concluímos que o dAMP se localiza na região da superfície das bicamadas do DODAB e se comporta como um íon grande. Este resultado deverá ser considerado na análise estrutural da interação DNA/vesículas lipídicas em nível molecular. / Though less efficient than viral vectors, cationic lipids have been used as carriers in gene therapy. They offer several advantages over viral vectors, including the low immunogenic and inflammatory responses, the potential transfer of unlimited-size expression units, and the possibility for engineered cell-specific targeting. However, the interaction between cationic lipids and genetic material needs to be better understood for the optimization of the transfection protocol. In the present work, we study the interaction between the nucleotide 2´-deoxyadenosine 5´-monophosphate (dAMP) and cationic liposomes of dioctadecyl dimethylammonium (DODAB), through the analysis of the electron spin resonance (ESR) spectra of spin labels incorporated in the bilayers. DODAB gel phase structure is not much affected by dAMP. The observed packing effect at the bilayer core seems to be related to the expected electrostatic screening effect at the bilayer surface, bringing the headgroups closer together, due to the presence of anions at the surface. In DODAB fluid phase, above 44 oC, ESR results strongly suggest that the relatively large double charged molecule of DMP is localized at the bilayer surface, but incorporated in the membrane, such that it is able of somehow space the headgroups, turning the bilayer core less packed and more hydrated. This result is certainly relevant for the structural understanding of the DNA-cationic membrane interaction on a molecular level.

Embora menos eficientes que os vetores virais, lipídios catiônicos têm sido cada vez mais usados como transportadores de material genético. Eles têm como vantagens em relação aos transportadores virais, a baixa imunidade, controle de qualidade e produção em grande quantidade, entre outros. Todavia, a interação entre lipídios catiônicos e material genético ainda é pouco compreendida. No presente trabalho, estudamos a interação entre o anfifílico catiônico brometo de dioctadecildimetilamônio (DODAB) e o nucleotídeo 2´-desoxiadenosina 5´-monofosfato (dAMP). Para tanto, utilizamos a técnica de Ressonância Paramagnética Eletrônica (RPE) aplicada a marcadores de spin derivados do ácido esteárico incorporados em vesículas de DODAB. Os resultados mostraram que na fase gel, na região próxima à superfície das bicamadas de DODAB, o dAMP causa muito pouca alteração na fluidez da membrana, enquanto que, na região do centro da bicamada, o dAMP diminui a fluidez da membrana, o que pode ser um efeito apenas de cargas, isto é, devido à blindagem eletrostática. Já na fase fluida, em ambas as regiões o dAMP aumenta a fluidez da membrana, sendo que, no centro das bicamadas induz um acréscimo significativo na polaridade do meio. A transição de fase gel-fluida do DODAB não sofre modificações com o acréscimo de dAMP. De uma maneira geral, nossos resultados mostraram que o dAMP não causa grandes modificações na estrutura do DODAB. Concluímos que o dAMP se localiza na região da superfície das bicamadas do DODAB e se comporta como um íon grande. Este resultado deverá ser considerado na análise estrutural da interação DNA/vesículas lipídicas em nível molecular. / Though less efficient than viral vectors, cationic lipids have been used as carriers in gene therapy. They offer several advantages over viral vectors, including the low immunogenic and inflammatory responses, the potential transfer of unlimited-size expression units, and the possibility for engineered cell-specific targeting. However, the interaction between cationic lipids and genetic material needs to be better understood for the optimization of the transfection protocol. In the present work, we study the interaction between the nucleotide 2´-deoxyadenosine 5´-monophosphate (dAMP) and cationic liposomes of dioctadecyl dimethylammonium (DODAB), through the analysis of the electron spin resonance (ESR) spectra of spin labels incorporated in the bilayers. DODAB gel phase structure is not much affected by dAMP. The observed packing effect at the bilayer core seems to be related to the expected electrostatic screening effect at the bilayer surface, bringing the headgroups closer together, due to the presence of anions at the surface. In DODAB fluid phase, above 44 oC, ESR results strongly suggest that the relatively large double charged molecule of DMP is localized at the bilayer surface, but incorporated in the membrane, such that it is able of somehow space the headgroups, turning the bilayer core less packed and more hydrated. This result is certainly relevant for the structural understanding of the DNA-cationic membrane interaction on a molecular level.

This study explores and describes the experiences of hearing children growing up in Deaf Parented families in Gauteng. The specific objectives of the study were to explore the delegation of different roles including South African Sign Language interpreting in the family; the influence of having Deaf parents in occupational choices of hearing adult-children of Deaf parents; the availability of support services to CODAs and their perceptions of their parents in terms of disability. A purposive sampling strategy in conjunction with snowball sampling was used to identify and recruit participants. Two males and eight females between the ages of 21 and 40 years, with different occupations were recruited for this study. A qualitative design, embedded within the constructivism and interpretivism framework was used in this study. Data were collected through semi structured; open ended and in-depth interview questions were used to obtain data for the study. A pilot study was conducted prior to commencing with the main study. Thematic content analysis was employed to describe themes qualitatively. The following themes emerged from the study. Participants reported to have developed a bicultural identity; however, they primarily identify themselves as CODAs regardless of their racial identity. Participants expressed frustrations with the interpreter role and female children reported to have interpreted for their parents more than their male counterparts. Seven participants are currently employed as SASL interpreters. The study highlights that there are mixed emotions regarding interactions with the extended family members. The study identifies a strong need for support services for Deaf parented families. Lastly; participants viewed Deafness as a cultural minority, and not a disability. Findings revealed a need for audiologists to clearly define their role in Deaf parented families, and to also adopt emic view of Deafness and family system perspective model.

Magister Scientiae - MSc / This thesis presents an approach for automatically generating signing animations from a sign language notation. An avatar endowed with expressive gestures, as subtle as changes in facial expression, is used to render the sign language animations. SWML, an XML format of SignWriting is provided as input. It transcribes sign language gestures in a format compatible to virtual signing. Relevant features of sign language gestures are extracted from the SWML. These features are then converted to body animation pa- rameters, which are used to animate the avatar. Using key-frame animation techniques, intermediate key-frames approximate the expected sign language gestures. The avatar then renders the corresponding sign language gestures. These gestures are realistic and aesthetically acceptable and can be recognized and understood by Deaf people. / South Africa

Doctor Pharmaceuticae - DPharm / South Africa's White Paper for the transformation of the health care system in South Africa (DOH, 2007) acknowledges major disparities and inequalities as a result of an imprint by apartheid policies. In its transition to democracy, health promotion strategies have been initiated to address these disparities. However, such strategies have been narrowed and "favoured target audiences that are literate, urban-based and who have easy access to print and audio-visual media" (DOH, 1997). This implies that many vulnerable and marginalised groupings in South Africa, including the Deaf community are excluded from health promotion endeavours. Deaf people in South Africa communicate using South African Sign Language (SASL) and majority of the Deaf community exhibit poor literacy levels. Deafness is a significant communication barrier which limits a Deaf person's prospect to attain the best possible health care (Barnett, et al 2011). Various means of communication including spoken language, written instructions and the use of pictograms are used by healthcare workers to communicate health-related information. For many members of the Deaf community who communicate primarily in sign language, these methods are a sub-standard and prevent the attainment of optimum therapeutic outcomes. With regard to pharmaco-therapeutic services, Deaf people cannot hear the spoken language used by pharmacists during patient counselling, and their compromised functional literacy hinders the ability to read instructions on medicine labels. With both the spoken and written means of communication compromised, the Deaf patient's ability to comprehend instruction by pharmacists on how to use their medicines is inadequate and as a result, a Deaf patient may leave the pharmacy with medicine, but a poor understanding of how to use the medicine safely and effectively. Previous researchers have worked on building a technology base, including industrial design and computer science expertise to conceptualize the groundwork of a mobile phone application called SignSupport to facilitate communication between medical doctors and Deaf individuals. The particulars of the pharmacy scenario however, require a pharmacy-specific device to be of use in the dispensing of medicines to a Deaf patient in a pharmacy. The over-arching goal of this thesis is to design and evaluate a mobile phone application to facilitate the communication of medicine instructions between a Deaf patient and a pharmacist. Qualitative, participatory action research and community-based co-design strategies were directed toward Deaf participants, senior pharmacy students and pharmacists to create a prototype of the afore-mentioned mobile phone application. Preliminary results indicated that the application was suitable to pharmacists and Deaf community. Furthermore, both sets of users approved the overall design and were receptive to and keen on the practical uses of the application. Inadequacies pointed out by the Deaf community and pharmacists were addressed as an iterative modification to the prototype and culminated in version 2 which was deployed in an actual hospital pharmacy in 2015. Hospital usability studies generated largely positive results from both Deaf users and pharmacists, indicating that SignSupport is able to facilitate communication between pharmacists and Deaf patients. Next steps include advancing the application to a market–ready version that is downloadable and available as an application on the play stores of commercially available smart phones. / National Research Foundation

Masters of Science / Much work has been done in building systems that can recognise gestures, e.g. as a component of sign language recognition systems. These systems typically use whole gestures as the smallest unit for recognition. Although high recognition rates have been reported, these systems do not scale well and are computationally intensive. The reason why these systems generally scale poorly is that they recognize gestures by building individual models for each separate gesture; as the number of gestures grows, so does the required number of models. Beyond a certain threshold number of gestures to be recognized, this approach becomes infeasible. This work proposes that similarly good recognition rates can be achieved by building models for subcomponents of whole gestures, so-called cheremes. Instead of building models for entire gestures, we build models for cheremes and recognize gestures as sequences of such cheremes. The assumption is that many gestures share cheremes and that the number of cheremes necessary to describe gestures is much smaller than the number of gestures. This small number of cheremes then makes it possible to recognize a large number of gestures with a small number of chereme models. This approach is akin to phoneme-based speech recognition systems where utterances are recognized as phonemes which in turn are combined into words. We attempt to recognise and classify cheremes found in South African Sign Language (SASL). We introduce a method for the automatic discovery of cheremes in dynamic signs. We design, train and use hidden Markov models (HMMs) for chereme recognition. Our results show that this approach is feasible in that it not only scales well, but it also generalizes well. We are able to recognize cheremes in signs that were not used for training HMMs; this generalization ability is a basic necessity for chemere-based gesture recognition. Our approach can thus lay the foundation for building a SASL dynamic gesture recognition system.

Research conducted on the prevalence of behavioural adjustment in Deaf children and adolescents, in erstwhile countries, points towards an appreciably elevated percentage of emotional and behavioural problems amongst this population group when compared to hearing normative groups. Studies specify that the prevalence of behaviour and emotional problems in Deaf children and adolescents varies from 4.8% to 50.3%. From existing research conducted, it is ambiguous as to why the reported prevalence rates of maladjustment are higher amongst Deaf children and adolescents. This pioneering study is the first of its kind to research dissimilar modalities of language used as the language of learning and teaching (LoLT) in schools for Deaf learners and how this could possibly correlate to learner behaviour in the classroom. Taking into consideration the reported pervasiveness of maladjustment in Deaf children and adolescents; this study uses the Teacher Report Form (TRF) to investigate the types of behaviour problems displayed by Deaf learners in the classroom. It further investigates whether Deaf learners display certain types of behaviour problems when dissimilar modalities of language are used as the language of learning and teaching. The overall findings of this study suggest that teachers who use manually coded spoken language report an elevated prevalence of behaviour problems on the TRF compared to teachers who use South African Sign Language (SASL). Results further suggest that the group of teachers who use SASL report somatic complaints and attention problems as the most frequently encountered behaviour problems in their classrooms. In comparison the group of teachers who use manually coded spoken English (MCE) report social problems and attention problems as the most frequently encountered behaviour problems in their classrooms. Limitations of this study and suggestions for future research are discussed.

<p>This thesis presents an approach for automatically generating signing animations from a sign language notation. An avatar endowed with expressive gestures, as subtle as changes in facial expression, is used to render the sign language animations. SWML, an XML format of SignWriting is provided as input. It transcribes sign language gestures in a format compatible to virtual signing. Relevant features of sign language gestures are extracted from the SWML. These features are then converted to body animation pa- rameters, which are used to animate the avatar. Using key-frame animation techniques, intermediate key-frames approximate the expected sign language gestures. The avatar then renders the corresponding sign language gestures. These gestures are realistic and aesthetically acceptable and can be recognized and understood by Deaf people.</p>

<p>This thesis presents an approach for automatically generating signing animations from a sign language notation. An avatar endowed with expressive gestures, as subtle as changes in facial expression, is used to render the sign language animations. SWML, an XML format of SignWriting is provided as input. It transcribes sign language gestures in a format compatible to virtual signing. Relevant features of sign language gestures are extracted from the SWML. These features are then converted to body animation pa- rameters, which are used to animate the avatar. Using key-frame animation techniques, intermediate key-frames approximate the expected sign language gestures. The avatar then renders the corresponding sign language gestures. These gestures are realistic and aesthetically acceptable and can be recognized and understood by Deaf people.</p>

>Magister Scientiae - MSc / This thesis presents a system for performing whole gesture recognition for South African Sign Language. The system uses feature vectors combined with Hidden Markov models. In order to construct a feature vector, dynamic segmentation must occur to extract the signer's hand movements. Techniques and methods for normalising variations that occur when recording a signer performing a gesture, are investigated. The system has a classification rate of 69%.