Article 2(1) of the UN Charter states that “the organisation is based on the principle of the sovereign equality of all its Members.” It cannot be disputed that the international community as a whole supports the fact that a state’s right to sovereignty is considered to be its most sacred international law right, which also includes sovereignty over its air space. Without this right, a state cannot exist and the United Nations cannot function. The parameters are clear and entrenched in international law as to when and how a state may use force against intrusion by a foreign military aircraft of another state in order to protect its right to sovereignty over its air space. However, international uncertainty and much debate exist as to the nature of civilian aerial intrusions into the airspace of another state. From an objective perspective, it appears that international law provides for a clear legal framework in that force may not be used against a civilian aircraft intruder unless it is facing an armed attack and acting in self-defence as defined in the Charter of the United Nations. This statement could not be further from the truth and it seems that even in our current modern, technologically advanced society we live in today where we can put a man on the moon and operate our household appliances from our phones, we cannot reach consensus as to what constitutes an armed attack by civilian aircraft or when and how a state may use force when a civilian intrusion of its airspace occurs. Consider the following scenario: A civilian aircraft of state A takes off on a route which requires it to cross the sovereign air space of state B. State B does allow for this type of crossing, provided that the civilian aircraft keeps to its designated route and does not enter any unrestricted areas of state B which requires pre-authorisation before entering. The civilian aircraft enters the airspace of state B, however, for no apparent reason, it deters from its designated route and heads towards a restricted area of state B. Air Traffic Control (“ATC”) of state B calls upon the pilot to return to its designated route, however due to some form of malfunction error, no communication can be established or alternatively, communication is established, but the pilot confirms it is heading to state C and proceeds to travel on the unauthorised route. In the absence of knowing the aircraft’s intention and in fear for state B’s national security, state B immediately sends an interceptor jet in an attempt to intercept the aircraft, but to no avail can either ATC or the interceptor jet manage to establish contact with the aircraft. As a last resort, the interceptor jet attempts to force the aircraft to land at the closest runway but the aircraft refuses/fails to take any recognisance of this attempt and proceeds on the unauthorised route (hereinafter referred to as “the Scenario”). Even with the inception of Article 3bis (as further described in 2.3 below), which was adopted for this specific international issue, there are still a lack of agreement amongst the international community as to the parameters in which to operate when a state finds itself in a situation as set out in the Scenario. This issue forms the crux of this paper and the writer will attempt to, by applying various applicable international laws, including customary laws, establish a universal set of guidelines which states can apply when having to deal with situations similar to the Scenario. / Mini Dissertation (LLM)--University of Pretoria, 2019. / Public Law / LLM / Unrestricted

A principal forma biológica do selênio em vários organismos é o aminoácido Selenocisteína (Sec, U), que é incorporado em um polipeptídio emergente em códons UGA específicos. Em Escherichia coli, esta incorporação requer os genes que codificam para Seril-tRNA Sintetase (SerRS), Selenocisteína Sintase (SELA), um tRNASec específico (SELC), Selenofosfato Sintetase (SELD) e um fator de elongação de transcrição específico (SELB). A proteína Selenofosfato Sintetase (EC 2.7.9.3) pertence à família AIRS, de proteínas que têm o ATP como substrato, e produz o composto biologicamente ativo doador de selênio, o monoselenofosfato, a partir de ATP e seleneto. O gene selD em E. coli tem 1041 pares de bases e codifica uma proteína com 347 aminoácidos e massa molecular de 37 kDa. A fase aberta de leitura do gene selD foi amplificada do DNA genômico de E. coli e clonada em vetor de expressão pet28a(+) (Novagen). A proteína recombinante foi superexpressa em E. coli por indução com IPTG e purificada por cromatografia de afinidade por ligação a metal e a fração eluída foi concentrada por ultrafiltração. Em seguida, o produto foi submetido à clivagem da cauda de histidinas com Trombina. Para purificar o produto de reação de clivagem com protease e para estimar sua massa molecular e estado oligomérico, empregou-se cromatografia de exclusão molecular. A proteína pura foi utilizada em experimentos de Gel Nativo e em estudos das suas propriedades hidrodinâmicas realizados por meio de Espalhamento Dinâmico de Luz (DLS), Espalhamento de Raios-X a Baixo Ângulo (SAXS) e Ultracentrifugação Analítica (AUC). Os resultados obtidos revelam uma mistura de oligômeros em solução, em um equilíbrio dímero-tetrâmero e tetrâmero-octâmero. Um modelo tridimensional para o homodímero de SELD de E. coli foi obtido por Modelagem Molecular e suas propriedades hidrodinâmicas preditas concordam com aquelas obtidas experimentalmente. Adicionalmente, triagens de condições de cristalização da proteína revelaram condições em que a proteína cristaliza na forma de pequenas agulhas e ensaios de otimização por variação da concentração de agente precipitante e pH não resultaram em monocristais adequados para difração de raios-X. A análise do papel da SELD na via de biossíntese de Selenocisteínas levanta a hipótese de que esta proteína deve entregar o monoselenofosfato para o complexo SELA-SELC de modo que o selênio seja incorporado para formação do aminoácido Selenocisteína, já que os compostos de selênio são tóxicos quando estão livres na célula. Portanto, a investigação da interação da SELD com o complexo SELA-SELC foi observada pelo monitoramento da anisotropia de fluorescência do complexo SELA-SELC mediante titulação de SELD. A análise local da interação para manutenção do complexo SELD-SELA-SEC foi feita por meio de espectrometria de massas com troca H/D, que revelou possíveis sítios de interação na superfície da SELD. Os resultados mostrados neste trabalho ampliam o conhecimento sobre a via de biossíntese de Selenocisteína, revelando detalhes da interação da SELD com o complexo SELA-SELC. / The main biological form of selenium in several organisms is the amino acid Selenocysteine (Sec, U), which is incorporated into selenoproteins in specific UGA codons. In Escherichia coli, it requires the genes that codify to Seryl-tRNA Synthetase (SerRS), Selenocysteine Synthase (SELA), a specific tRNASec (SELC), Selenophosphate Synthetase (SELD) and a specific translation elongation factor (SELB). Selenophosphate Synthetase (EC 2.7.9.3) belongs to AIRS superfamily of proteins that have ATP as a substrate and this protein produces the biologically active selenium donor compound, monoselenophosphate, from ATP and selenide. The selD gene from E. coli is 1041 base pairs long and codifies a protein with 347 amino acids and molecular mass of 37 kDa. The open reading frame of selD gene was amplified from E. coli genomic DNA and cloned into pET28a(+) expression vector (Novagen). The recombinant protein was overexpressed in E. coli by IPTG induction and purified by metal affinity chromatography, and the eluted fraction was concentrated by ultrafiltration. The product was used for Thrombin protease cleavage of the 6-His tag. In order to purify the product of proteolysis and to estimate its molecular mass and oligomeric state, we used size exclusion chromatography. The pure protein sample was used for Native Gel Electrophoresis. Hydrodynamic properties of the protein were studied by Dynamic Light Scattering (DLS), Small angle X-ray scattering (SAXS) and Analytical Ultracentrifugation (AUC). The results show an equilibrium between SELD oligomeric forms, as dimer-tetramer and tetramer-octamer association in solution. A tridimensional model of E. coli SELD was obtained by Molecular Modelling and its predicted hydrodynamic properties agree with those observed experimentally. In addition, crystal screening revealed crystallization conditions suitable for protein crystallization as small needles, but optimization of these conditions by precipitant agent and pH variation did not result in monocrystals reliable for X-ray diffraction. An analysis of SELD´s role in the Selenocysteine biosynthesis pathway indicates that SELD must deliver monoselenophosphate to the SELA-SELC complex so that the selenium is incorporated to the amino acid to form selenocysteyl-SEC, since selenium compounds are toxic when they are freely available in the cell. This interaction was observed by fluorescence anisotropy. The local analysis of complex formation was monitored by mass spectrometry after H/D exchange and revealed possible sites for this interaction on SELD surface. The results improve our knowledge about the Selenocysteine pathway in the cell, showing details of the interaction between SELD and the SELA-SELC complex.

A principal forma biológica do selênio em vários organismos é o aminoácido Selenocisteína (Sec, U), que é incorporado em um polipeptídio emergente em códons UGA específicos. Em Escherichia coli, esta incorporação requer os genes que codificam para Seril-tRNA Sintetase (SerRS), Selenocisteína Sintase (SELA), um tRNASec específico (SELC), Selenofosfato Sintetase (SELD) e um fator de elongação de transcrição específico (SELB). A proteína Selenofosfato Sintetase (EC 2.7.9.3) pertence à família AIRS, de proteínas que têm o ATP como substrato, e produz o composto biologicamente ativo doador de selênio, o monoselenofosfato, a partir de ATP e seleneto. O gene selD em E. coli tem 1041 pares de bases e codifica uma proteína com 347 aminoácidos e massa molecular de 37 kDa. A fase aberta de leitura do gene selD foi amplificada do DNA genômico de E. coli e clonada em vetor de expressão pet28a(+) (Novagen). A proteína recombinante foi superexpressa em E. coli por indução com IPTG e purificada por cromatografia de afinidade por ligação a metal e a fração eluída foi concentrada por ultrafiltração. Em seguida, o produto foi submetido à clivagem da cauda de histidinas com Trombina. Para purificar o produto de reação de clivagem com protease e para estimar sua massa molecular e estado oligomérico, empregou-se cromatografia de exclusão molecular. A proteína pura foi utilizada em experimentos de Gel Nativo e em estudos das suas propriedades hidrodinâmicas realizados por meio de Espalhamento Dinâmico de Luz (DLS), Espalhamento de Raios-X a Baixo Ângulo (SAXS) e Ultracentrifugação Analítica (AUC). Os resultados obtidos revelam uma mistura de oligômeros em solução, em um equilíbrio dímero-tetrâmero e tetrâmero-octâmero. Um modelo tridimensional para o homodímero de SELD de E. coli foi obtido por Modelagem Molecular e suas propriedades hidrodinâmicas preditas concordam com aquelas obtidas experimentalmente. Adicionalmente, triagens de condições de cristalização da proteína revelaram condições em que a proteína cristaliza na forma de pequenas agulhas e ensaios de otimização por variação da concentração de agente precipitante e pH não resultaram em monocristais adequados para difração de raios-X. A análise do papel da SELD na via de biossíntese de Selenocisteínas levanta a hipótese de que esta proteína deve entregar o monoselenofosfato para o complexo SELA-SELC de modo que o selênio seja incorporado para formação do aminoácido Selenocisteína, já que os compostos de selênio são tóxicos quando estão livres na célula. Portanto, a investigação da interação da SELD com o complexo SELA-SELC foi observada pelo monitoramento da anisotropia de fluorescência do complexo SELA-SELC mediante titulação de SELD. A análise local da interação para manutenção do complexo SELD-SELA-SEC foi feita por meio de espectrometria de massas com troca H/D, que revelou possíveis sítios de interação na superfície da SELD. Os resultados mostrados neste trabalho ampliam o conhecimento sobre a via de biossíntese de Selenocisteína, revelando detalhes da interação da SELD com o complexo SELA-SELC. / The main biological form of selenium in several organisms is the amino acid Selenocysteine (Sec, U), which is incorporated into selenoproteins in specific UGA codons. In Escherichia coli, it requires the genes that codify to Seryl-tRNA Synthetase (SerRS), Selenocysteine Synthase (SELA), a specific tRNASec (SELC), Selenophosphate Synthetase (SELD) and a specific translation elongation factor (SELB). Selenophosphate Synthetase (EC 2.7.9.3) belongs to AIRS superfamily of proteins that have ATP as a substrate and this protein produces the biologically active selenium donor compound, monoselenophosphate, from ATP and selenide. The selD gene from E. coli is 1041 base pairs long and codifies a protein with 347 amino acids and molecular mass of 37 kDa. The open reading frame of selD gene was amplified from E. coli genomic DNA and cloned into pET28a(+) expression vector (Novagen). The recombinant protein was overexpressed in E. coli by IPTG induction and purified by metal affinity chromatography, and the eluted fraction was concentrated by ultrafiltration. The product was used for Thrombin protease cleavage of the 6-His tag. In order to purify the product of proteolysis and to estimate its molecular mass and oligomeric state, we used size exclusion chromatography. The pure protein sample was used for Native Gel Electrophoresis. Hydrodynamic properties of the protein were studied by Dynamic Light Scattering (DLS), Small angle X-ray scattering (SAXS) and Analytical Ultracentrifugation (AUC). The results show an equilibrium between SELD oligomeric forms, as dimer-tetramer and tetramer-octamer association in solution. A tridimensional model of E. coli SELD was obtained by Molecular Modelling and its predicted hydrodynamic properties agree with those observed experimentally. In addition, crystal screening revealed crystallization conditions suitable for protein crystallization as small needles, but optimization of these conditions by precipitant agent and pH variation did not result in monocrystals reliable for X-ray diffraction. An analysis of SELD´s role in the Selenocysteine biosynthesis pathway indicates that SELD must deliver monoselenophosphate to the SELA-SELC complex so that the selenium is incorporated to the amino acid to form selenocysteyl-SEC, since selenium compounds are toxic when they are freely available in the cell. This interaction was observed by fluorescence anisotropy. The local analysis of complex formation was monitored by mass spectrometry after H/D exchange and revealed possible sites for this interaction on SELD surface. The results improve our knowledge about the Selenocysteine pathway in the cell, showing details of the interaction between SELD and the SELA-SELC complex.

Made available in DSpace on 2016-12-08T16:24:10Z (GMT). No. of bitstreams: 1 PGCA11MA081.pdf: 22717 bytes, checksum: 41112e9e69fe9ceac2afe9b11e56e60f (MD5) Previous issue date: 2011-02-25 / Trypanosoma evansi is the pathogenic trypanosomatid with the worldwidest distribution, generating economic losses in Africa, South America, Europe, Asia and Oceania. This protozoan is the etiologic agent of the disease know as Surra or Mal das Cadeiras, wich affects almost all species of mammals, with a recent case in humans. An important metabolic pathway described in all the three kingdoms of life is the incorporation of selenium into proteins, wich mainly has an antioxidant function. Selenium is used in the form of the amino acid selenocysteine, which is incorporated into the nascent polypeptide co-translationally through the stop codon "UGA". Some elements plays a key role into this pathway: a signaling nucleotide structure in the messenger RNA (SECIS), a specifc tRNA (tRNASec) and an enzyme complex that allows the conversion of selenium in its active form monoselenophosphate (SPS), its aminoacylation in tRNASec (SerRS, PSTK, SepSecS) and the coupling of nucleotidic and proteic structures (SECIS, EF-Sec, SBP2) in the UGA codon to translation and insertion of selenocysteine into the protein. This work demonstrated that T. evansi express the genes selB (EF-Sec), selC (tRNASec), selD (SPS) and pstk in its mRNA. The domains analysis of T. evansi selB, selD and PSTK genes found regions that are consistent with the predicted proteins functions. The predicted secondary structure of T. evansi tRNASec shares the most of the characteristics of eukaryotic tRNASec. Using Southern Blot, we showed that selB, selD and pstk are single copie genes in T. evansi genomic DNA. The SPS proteis was correctly localized in the total protein extract of the parasite, with a 43 kDa band. The same protein has a cytoplasmatic localization in T. evansi, as showed by indirect immunofluorescence. The gene of a trypanosomatid exclusive selenoprotein, selTRYP, was amplified of the cDNA and sequenced. Through these results, we suggest that T. evansi is capable of using selenium for the formation of selenoproteins, and the presence of the selTRYP, selb, selc, seld and pstk genes may indicate a potential future therapeutic target, since recent data show an increase in the parasite resistance to the commercial available drugs in different continents / O Trypanosoma evansi é o tripanossomatídeo patogênico de maior distribuição mundial, causador de prejuízos econômicos na África, América do Sul, Europa, Ásia e Oceania. Este protozoário é o agente etiológico da doença conhecida como Surra ou Mal das Cadeiras, que afeta praticamente todas as espécies de mamíferos, com um recente caso em humanos. Uma importante via metabólica descrita em todos os reinos da vida é a incorporação de selênio em proteínas, com função, principalmente, antioxidante. O selênio é utilizado na forma do aminoácido selenocisteína, que é incorporada ao polipeptídeo nascente co-traducionalmente através do códon de parada UGA . Para que isto ocorra, são necessárias uma estrutura nucleotídica sinalizadora no RNA mensageiro (SECIS), um RNA transportador específico (tRNASec) e um complexo de enzimas que permitem a conversão do selênio em sua forma ativa, monoselenofosfato (SPS), sua aminoacilação no tRNASec (SerRS, PSTK, SepSecS) e o acoplamento de estruturas nucleotídicas e protéicas (SECIS, EF-Sec, SBP2) para que o códon UGA seja traduzido em selenocisteína e a mesma seja inserida na proteína. Neste trabalho foi demonstrado que o T. evansi expressa os genes selB (EF-Sec), selC (tRNASec), selD (SPS) e PSTK. A análise de domínios dos genes selB, selD e PSTK de T. evansi encontrou regiões condizentes com as características funcionais das proteínas formadas. A estrutura secundária predita do tRNASec de T. evansi compartilha a maioria das características dos tRNASec de eucariotos. Através da técnica de Southern Blot, demonstrou-se que os genes selB, selD e PSTK possuem cópia única no DNA genômico de T. evansi. Utilizando-se Western Blot, a proteína SPS foi localizada corretamente no extrato protéico do protozoário, formando uma banda de 43 kDa. Foi realizada também uma imunolocalização da SPS, sendo que a mesma possui localização citoplasmática neste protozoário. O gene de uma selenoproteína exclusiva de tripanossomatídeos, a selTRYP, foi amplificado do cDNA e parcialmente sequenciado. Através desses resultados, sugere-se que o T. evansi é capaz de utilizar selênio para a formação de selenoproteínas, e a presença dos genes da via de inserção de selenocisteína pode indicar um potencial futuro alvo terapêutico, visto que recentes dados demonstram um crescimento de cepas resistentes aos medicamentos disponíveis no mercado em vários continentes

<p>The intent of this study is to consider changes in the naturalization of the self-as-object in both behavioral and mental spheres, or the "self-as-instrument" and "self-consciousself", respectively. The concern here is on the naturalness versus historicalness accorded these two aspects of the self-as-object. A focused examination of the treatment of the self-as-object in three theoretical schools, the Chicago School, Mass Society Theory, and Post-Modern school, assists in drawing the conclusion that the more the self-as-object is separated in these two spheres, the more the self-as-instrument, and in particular and self-as-egoistic-instrument, is naturalized. Further attendant with this separation is a selfconscious-self that becomes an increasingly historical and problematic construct.</p> / Thesis / Master of Arts (MA)

Submitted in accordance with the requirements for the for the degree of Master of Technology in Photography, Durban University of Technology, Durban, South Africa, 2015. / This dissertation is a self-study that involves inquiring into my mentoring practice to change and improve my situation and find a sense of belonging. The centre of the inquiry into 'self' lies in the search and claiming of an identity that consolidates the development of my artistic, mentoring and research practices during my 'first time' employment experience, as a junior lecturer in a Photography program, 2009-2011. I reflect on three years of lecturing experience in a tertiary education setting at the Durban University of Technology, in which doing a Masters was obligatory. I entered this position, with little experience in research and lecturing or photographic expertise. During this study, I made myself known as osmosisliza, the name of the ‘cyborg’ who journeys in cyberspace. I claim to be a ‘photographer horticulturalist’, a mentor concerned with cultivating collective online spaces, to create movement to connect in cyberspace for social learning purposes. I ask “Who is osmosisliza?”. My class motto is “what you think, know and believe helps us all to be more”, a personal belief for building knowledge through exchange and collaboration with others. I employed a variety of free Web 2.0 applications, like Gmail, Blogger, Buzz, Picasa Web Albums, Google Bookmarks and YouTube to create online spaces in which I could position my living educational theory. I called this place the Google Lens (GL). The Google Lens formed the mechanism to cultivate communities of practice for social learning, to develop confidence, motivation and engagement. The Google Lens was also the repository for qualitative and quantitative data. Mostly I analyse verbal and visual text, writings, photographs and video exchanges between learners and myself archived in the Google Lens to address my research question and sub-question. Through the lens of Google I did action research to improve my practice, and analyse my development as a newcomer to academia. I investigate how successful I was in using the Google Lens to achieve my mentoring goals. I also made photographs during the process of this inquiry to visually address abstract identity dilemmas, concerns and thoughts in my place of work, to engage my ‘I’ in my ‘eye’ as photographer. I exhibit these in cyberspace. I call these electronic postcards. Electronic postcards are blog posts in a weblog called osmosisLIZA. I made 98 blog posts and sent 98 electronic postcards in this dissertation. An electronic postcard consists of a photograph, an illustration, labels and a text heading. In this document the electronic postcards run alongside the writings for this self-study, functioning as text and message of the experiences of a developing academic as well as evidence of the developmental questions I was continuously asking to improve my practice.