Tesis doctoral--Calgary, 1979. / Bibliogr. p. 127-136.

Diss. Ph. D.--University of Umeå, 1983.

Doctoral diss.--Göteborg universitet, 1994. / Bibliogr. p. 147-163.

Th. 3e cycle--Archéol.--Paris 1, 1986. / Bibliogr. p. 101-109.

Texte remanié de: Th.--Archaeology and anthropology--Camberra--Australian national university, 1986. / Bibliogr. p. 160-168.

Texte remanié de: Habilitationsschrift--Heidelberg Universität, 1988. / Bibliogr. p. 269-281.

Doct. diss.--Department of Archeology--Umeå, 1989. / Résumé en Anglais. Bibliogr. p.[169]-174. Index.

Thesis (MPhil)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The Ministry of Information of Eritrea is basically aimed at providing the society with news, information, education and entertainment. In addition to its service presentation through radio, TV and printed press the Ministry of Information has taken the initiative to present its services in the digital way by publishing a website known as shabait.com. But as the technique is new to the country as well as to the organization, it is to be expected that there will be inaccuracies in the way the website was designed. Hence, evaluating and redesigning shabait.com with the goal of making it informative, attractive and easy to use will be very beneficial to the organization as well as to users of the website. This recently launched website is not very attractive and not successfully directed to its users. Therefore, the main aim of this study is to assess and find the best way of presenting information digitally to the Eritrean society, as well as to anyone interested in finding out about Eritrea through the State owned media website. This study was firstly approached by gathering previously written relevant information from books, journals, and the Internet. In addition to that interviews with concerned people in Eritrea were held to understand the aim, difficulties and challenges of the website. Subsequently the website was assessed according to the evaluation criteria developed, based on the literature review. The evaluation of the website assumed three different approaches of qualitative as well as quantitative types. A usability test with both quantitative and qualitative questions was done through a questionnaire, which was analyzed statistically. A competitive analysis, of qualitative type with two international websites was also made. In order to create a good quality website, it is essential to have clearly specified goals, policies and strategies, and adequate advanced human as well as technological resources, so that it will be easy to overcome the common challenges such as competition, diversity of users, budget constraints, and inadequacy of policy instruments. The findings of the evaluation of shabait.com indicate that the website is not attractive, is user unfriendly, of low content quality as well as with low download speed and, more importantly, was not advertised well. Therefore, shabait.com is not fit to be considered as a sole first hand information provider website for the Eritrean society as well as for anybody who is concerned about Eritrea. At the end of the study recommendations of how the website can be modified to be successful are listed. / AFRIKAANSE OPSOMMING: Die doelwit van die Ministerie van Inligting van Eritrea is om nuus, inligting, opvoeding en vermaak aan die gemeenskap te verskaf. Bykomend tot die radio, TV en die gedrukte media, het die Ministerie van Inligting nou ook besluit om 'n digitale diens te lewer deur middel van 'n webwerf bekend as shabait.com. Aangesien die betrokke tegnieke vir die land sowel as vir die organisasie iets nuuts is, kan daar verwag word dat die ontwerp van die webwerf onakkuraathede sal toon. Dus moet shabait.com evalueer en verbeter word om dit sodoende aantreklik en gebruikersvriendelik te maak; dit sal tot die voordeel strek van die organisasie so wel as die gebruikers. Hierdie jong webwerf is tans nie baie aantreklik of maklik om te gebruik nie. Dus is die doelwit van hierdie studie om die beste wyses te vind om die gemeenskap van Eritrea, sowel as ander belangstellendes, deur middel van 'n webwerf wat deur die staat beheer word, digitaal van inligting te bedien. Relevante geskrewe inligting is bekom deur middel van boeke, joernale en die Internet. Daar is ook onderhoude gevoer met mense betrokke by shabait.com om sodoende die doelwitte, probleme en uitdagings van die webwerf beter te verstaan. Daarna is die webwerf evalueer volgens ontwikkelde kriteria gebaseer op die literatuuroorsig. Vir die evaluasie is drie benaderings gebruik, beide kwalitatief en kwantitatief. 'n Bruikbaarheidstoets is deur middel van 'n vraelys gedoen met kwalitatiewe sowel as kwantitatiewe vrae en die antwoorde is statisties ontleed. Twee internasionale webwerwe is ook ontleed sodat hulle gehalte met dié van shabait.com vergelyk kon word. Om 'n webwerf van goeie gehalte te ontwerp, is dit noodsaaklik om duidelik omskrewe doelwitte, beleide en stategië, asook genoegsaam opgeleide mense en gevorderde tegnologiese hulpbronne te hê sodat die uitdagings soos kompetisie, verskeidenheid van gebruikers, begrotingsbeperkings en swak beleidsinstrumente oorkom kan word. Die bevindinge van die evaluasie van shabait.com toon dat die webwerf onaantreklik en gebruikersonvriendelik is, die inhoud is van swak gehalte, die aflaai spoed is laag en en die werf is nie goed adverteer nie. Daarom is die werf nie geskik om beskou te word as die enigste eerstehandse inligtingsverskaffer webwerf vir die gemeenskap van Eritrea sowel as ander belangstellendes nie. Aan die einde van die studie is daar aanbevelings vir die verbetering van die webwerf.

Passagens e desdobramentos entre o repouso e o isolamento na constituição de uma poética visual é uma reflexão sobre as relações existentes entre noções de repouso e de isolamento. As investigações são feitas através de proposições que envolvem peças tridimensionais, espaço de apresentação e imagens fotográficas criadas no período de 1998 a 2001. A análise focaliza passagens pelo processo de criação e apresentação dos trabalhos realizados, aproximações e distancias com pensamentos e obras de autores e artistas que tratam da permeabilidade entre proposições tridimensionais e circunstâncias específicas de apresentação. Para isto são vistos conceitos chaves como: espaço, lugar, não-lugar; site-specífic; site, non-site; in situ.

Glucansucrases são enzimas que atuam em reações de síntese de polissacarídeos e oligossacarídeos. Para que esses biocatalisadores sejam aplicados em escala industrial, é desejável ótimas estabilidades térmica e operacional, o que pode ser alcançado com a imobilização de enzimas. Como alternativa aos suportes sólidos amplamente estudados, está a quitosana, polímero que não apresenta toxicidade e possui alta biocompatibilidade e alta afinidade com proteínas. Outra possibilidade promissora na imobilização de enzimas, é a síntese dos agregados enzimáticos entrecruzados (CLEAs), os quais apresentam alta atividade catalítica e alta estabilidade. Contudo, uma peculiaridade das glucansucrases quando produzidas em meio contendo sacarose é a camada de polímero que as envolve, e que bloqueia o acesso aos grupos reativos na superfície da proteína. No caso da expressão heteróloga das glucansucrases em Escherichia coli essa dificuldade pode ser contornada. Além disso, o uso da mutagênese sítio-dirigida pode proporcionar modificações de aminoácidos na superfície da enzima, tais como os resíduos Lys, Cys, His, com o intuito de que melhorias na imobilização sejam alcançadas. Sendo assim, na primeira etapa desse trabalho, uma extensa discussão é apresentada em relação às metodologias de imobilização de dextransucrase encontradas na literatura. A seguir, estudos referentes à imobilização da dextransucrase de Leuconostoc mesenteroides B-512 F em esferas de quitosana ativadas com glutaraldeído foram realizados. Esse imobilizado apresentou alta atividade catalítica (197 U/g) quando utilizada a carga de proteína de 400 mg/g de suporte. Além disso, observou-se que a imobilização covalente e os açúcares maltose e glicose promoveram proteção à enzima em temperaturas de 40 ºC e 50 ºC. Na etapa seguinte, a produção e a caracterização de CLEAs de dextransucrase de L. mesenteroides B-512 F foram investigados. Demonstrou-se que o tratamento com a dextranase foi essencial para a imobilização da glucansucrase e que o isopropanol foi o melhor agente precipitante. Os CLEAs apresentaram pH e temperatura ótimos de 3,0 e 60 ºC, respectivamente, enquanto que a dextransucrase imobilizada nas esferas de quitosana funcionalizada com glutaraldeído apresentaram os valores de 4,5 e 20 ºC. Ambas formas imobilizadas apresentaram boa estabilidade operacional na síntese de oligossacarídeos uma vez que após 10 ciclos, 40 % de atividade residual foi observada. Por fim, estão apresentados estudos sobre a modelagem das estruturas tridimensionais e a mutagênese sítio-dirigida das glucansucrases DSR-S vardel Δ4N and ASR C-APY del. Os modelos preditos demonstraram boa qualidade e a mutagênese sítio-dirigida não promoveu perdas significativas na atividade enzimática dos mutantes. Somente o mutante DSR_S326C mostrouse inativo. Os resultados obtidos sugerem que a imobilização da dextransucrase foi satisfatória e que cada técnica possibilita diferentes características ao imobilizado. Além disso, os imobilizados foram adequados para síntese de dextrana e oligossacarídeos. / Glucansucrases are enzymes that catalyze the synthesis of polysaccharides and oligosaccharides. In order to assure continuous processing and reuse of the biocatalyst in industrial applications, enzyme immobilization techniques are required to promote good thermal and operational stabilities. Among the several solid supports for enzyme immobilization, chitosan shows interesting properties because it is non-toxic, it is biocompatible, and it has high protein affinity. Other possibility is the production of cross-linked enzyme aggregates (CLEAs), which presents high catalytic activity and good stability. However, glucansucrases have a particularity when produced in sucrose medium, since a polymer layer surrounds the protein, blocking the access to reactive groups on the enzyme surface. To overcome this problem, it is possible to make the heterologous production of glucansucrases in Escherichia coli. Likewise, the site-directed mutagenesis may promote changes in the amino acids located on the surface to improve immobilization parameters. Therefore, this work aimed to discuss the several techniques applied for dextransucrase immobilization, and to design new immobilized biocatalysts. In a first step, it is presented a review about the distinct immobilization methodologies for dextransucrase. In a second study, an investigation about dextransucrase from Leuconostoc mesenteroides B-512 F immobilized on glutaraldehyde-activated chitosan particles was carried out. The novel immobilized biocatalyst showed 197 U/g (400 mg/g dried support) of catalytic activity. The covalent immobilization promoted protection against enzyme damages at 40 ºC and 50 ºC, whereas maltose and glucose acted as stabilizers. Furthermore, it was studied the production and characterization of CLEAs dextransucrase from L. mesenteroides B-512 F. It was demonstrated that dextranase treatment was crucial for immobilization. Isopropanol was chosen as the best precipitant agent. CLEAs presented optimal pH and temperature of 3.0 and 60 ºC, respectively, whereas it was found values of 4.5 e 20 ºC for dextransucrase immobilized on glutaraldehyde-activated chitosan particles. Both immobilized biocatalysts showed good operational stability in the oligosaccharides synthesis, exhibiting 40 % of residual activity after 10 cycles. Finally, the study concerning the homology modeling and site-directed mutagenesis of glucansucrases DSR-S vardel Δ4N and ASR C-APY del is presented. The predicted models showed good quality and it has been demonstrated that the site-directed mutagenesis did not promote significant losses in the variant enzyme activities. Only one mutant (DSR_S326C) had shown no dextransucrase activity. The results obtained in this work suggest that the immobilization of dextransucrase was satisfactory, also showing that each technique promotes different characteristics to the immobilized biocatalyst. Besides, these immobilized enzymes were feasible for the synthesis of dextran and oligosaccharides.