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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Estudo da interação entre domínios C-terminais de septinas humanas: implicação na formação e estabilidade do filamento / Study of Interaction between human C-terminal domains septins: implication for filament formation and stability

Fernanda Angélica Sala 10 April 2015 (has links)
Septinas compreendem uma conservada família de proteínas de ligação a nucleotídeo de guanina e formação de heterofilamentos. Em termos estruturais, elas possuem uma organização comum: um domínio GTPase central, uma região N-terminal e um domínio C-terminal, este último é predito para formar estruturas em coiled coil. Atualmente, o heterocomplexo de septinas humanas (SEPT2/SEPT6/SEPT7) mais bem caracterizado revela a importância do domínio GTPase na formação do filamento, todavia a ausência de densidade eletrônica para os domínios C-terminais faz com que sua função permaneça obscura. Estudos com septinas de mamíferos, e de outros organismos como C. elegans e S. cerevisea sugerem que alguns grupos de septinas (por exemplo, II e IV em mamíferos) interagem através de seus domínios C-terminais, e estes poderiam atuar de modo determinante para a montagem correta do filamento. Assim, o presente projeto objetivou estudar a afinidade homo/heterotípicas para os domínios C-terminais das septinas humanas dos grupos II (SEPT6C/8C/10C/11C) e IV (SEPT7C), investigando se esses domínios contribuem para preferência das septinas interagirem com proteínas de grupos distintos durante a formação do heterofilamento. Os domínios C-terminais foram expressos em E. coli e purificados. Foram conduzidos estudos de ultracentrifugação analítica e espectropolarimetria de dicroísmo circular, que permitiram identificar maior afinidade e estabilidade da associação heterotípica comparada à homotípica. Foram obtidas constantes de dissociação aparente para homodímeros em torno de baixo µM, enquanto que para heterodímeros os dados já existentes no grupo revelaram constante de dissociação na ordem de nM. Para entender os fatores no nível atômico responsáveis pela significativa predileção na interação entre os domínios C-terminais dos grupos II e IV foram realizados estudos utilizando modelagem e análise das sequências primárias. As análises sugerem a presença de um alto número de resíduos carregados na posição a do coiled coil como responsável pela seletividade. Consequentemente, o heterodímero seria favorecido em virtude do menor efeito repulsivo proveniente do intercalamento dos resíduos carregados em a. Desse modo, os resultados indicaram a atuação decisiva ou cooperativa dos domínios C-terminais na organização preferencial das septinas durante a formação do filamento, favorecendo a interface NC entre septinas dos grupos II e IV. / Septins comprise a conserved protein family that binds guanidine nucleotide and forms heterofilaments. In structural terms they have a common organization: a central GTPase domain, a N-terminal domain and a C-terminal domain, this last one is predicted to form coiled coil structures. Currently, the human septin heterocomplex best characterized (SEPT2/SEPT6/SEPT7) reveals the importance of the GTPase domain in filament assembly, however the absence of electron density for the C-terminal domains makes its function still unknown. Studies with mammals septins, and of others organisms like C. elegans and S. cerevisea suggests that some septins groups (e.g. II e IV in mammals) interact via its C-terminal domains and this could act in a determinative way to correct filament assembly. In this way, this project aimed to study the homo/heterotypical affinity for the C-terminal domains of human septins belonging to groups II (SEPT6C/8C/10C/11C) e IV (SEPT7C), investigating whether this domain contributes with the preference of septins to interact with proteins of different groups during assembly of the heterofilament. The C-terminal domains were expressed in E. coli and purificated. It was carried out studies using analytical ultracentrifugation and circular dichroism spectropolarimetry tecniques which allowed identification of major affinity and stability in the heterotypical association compared to homotypical. It was measured apparent dissociation constants for homodimers of low µM range while for heterodimers our group\'s data shows dissociation constants in the nM range. To understand at atomic level the factors responsible for this significant preference in the C-terminal domains interaction between groups II and IV was performed molecular modelling studies and analysis of the primary sequence. These analysis suggests the presence of a high number of charged residues in position a of the coiled coil as responsible for selectivity. Consequently, the heterodimer would be therefore favoured because of the minor repulsive effect coming from the staggered of charged residues in a. Thus, these results indicate the crucial or cooperative action of C-terminal domains in preferential organization of septins during filament assembly, favouring the NC interface between septins of groups II and IV.
92

Real-Time Communication over Broadcast Networks

Forss, Jonas January 1999 (has links)
Today the utilization of all kind of multimedia services in networks increases and due to this demand for real-time communication gets higher for every day. One of the most common protocols used today is Ethernet. It is of interest to find real-time protocols that are useful together with already existing protocols since it is expensive to rebuild the network infrastructure. Several new protocols have been proposed to solve the upcoming problems. The objective of this project is to make an inventory and a comparison between Ethernet and these new protocols. During this project four different protocols capability to fulfill the demands for real-time communication have been studied and compared with Ethernet. Three of the protocols are built on the same basic technique as Ethernet and these are PCSMA, CSMA-DCR and DOD-CSMA-CD. The fourth protocol is ATM and it transmits in a different way over communication networks. The analysis of this project is pointing out advantages, similarities and differences between the protocols from a real-time perspective. All four protocols are more suitable for real-time requirements than Ethernet.
93

Framtiden för CD-skivan som musikformat : En undersökning av CD-formatets roll på musikmarknaden

Fladvad, Anton January 2016 (has links)
Sedan början på 2000-talet har försäljningssiffrorna för CD-skivan inom musikindustrin varit på nedgång och minskat årligen, samtidigt som de nya digitala formaten har etablerats på den globala marknaden. Men trots många spekulationer, där CD-skivan sedan år tillbaka har stämplats som ett döende musikmedium, tyder försäljningsstatistiken på att CD:n och andra fysiska format fortfarande har en plats på den moderna globala musikmarknaden. I denna undersökning sammanställs försäljningssiffror från världens största musikmarknader, samt Sverige, för att få en tydligare överblick över hur försäljningsfördelningen egentligen ser ut mellan de olika musikformaten. Genom sekundäranalys, kombinerat med Boltanski och Thénevots teori om de olika typer av världar som existerar i vardagen, och deras respektive värdeordningar, analyseras den insamlade datan för att få en ökad förståelse för varför försäljningsfördelningen ser ut som den gör idag, och hur utvecklingen har sett ut under föregående år. Resultatet visar att den globala försäljningsfördelningen under 2014 var jämnt fördelad mellan digitala och fysiska format, med en andel på cirka 46% vardera av den totala globala musikmarknaden. Detta visar att fysiska format, trots en årlig minskning, år 2014 hade en roll på musikmarknaden som, ur försäljningsaspekt, var likvärdig digitala format, och CD-skivan (och även vinylen) kan därför inte ännu anses vara död.
94

Infrastruktura pro testování a nasazení real-time lokalizační platformy / Infrastructure for Testing and Deployment of the Real­-Time Localization Platform

Ormoš, Michal January 2020 (has links)
Táto práca je prípadovou štúdiou postupného vývoja a nasadzovania lokačného softwaru v reálnom čase. Cieľom tejto práce je zrýchliť tento proces. Zvolený problém bol vyriešený s konvenčnými testovacími nastrojmi, vlastným nástrojom pre generovanie sieťovej prevádzky lokalizačnej platformy a nástrojmi CI/CD Gitlab. Prínosom tejto práce je zrýchlenie vývoja, zaručenie kvality vyvijaného softwaru a predstavenie spôsobu ako platformu pre lokalizáciu v reálnom čase testovať.
95

Určení vlivu iontů ve struktuře hydroxidu nikelnatého / The influence of metal ions on nickel hydroxide structure

Navrátil, Jan January 2010 (has links)
Diploma thesis is involved in basic properties of nickel materials for alkaline accumulators. Practical part deals with measuring of nickel hydroxides by cyclic voltametry. Next practical part is above measuring and optimalization various proportion of nickel and cobalt in layer made by electrodeposition on nickel electrodes.
96

End-user training of post-graduate students in the use of CD-ROM databases with special reference to the University of the North

Letshela, Phegello Zacharia January 1995 (has links)
Thesis (M.A) - RAU, 1995 / Refer to document
97

Langzeitkultur von humanen Langerhanszellen

Henschke, Cornelia 23 February 2001 (has links)
Die Arbeit beschreibt das phänotypische Verhalten von kultivierten Langerhanszellen, antigenpräsentierenden Zellen der Epidermis, sowie die Art und Weise ihrer Elimination. Hierfür wurden Zellkulturen von Langerhanszellen durch Migration aus normaler menschlicher Haut gewonnen. Die Langerhanszellen durchlaufen dabei die gleiche funktionelle Entwicklung, wie nach Antigenpräsentation in situ. Ziel der Untersuchung war es, die funktionellen und zellulären Eigenschaften und die Elimination von Langerhanszellen in der Zellkultur zu ermitteln. Die Anzahl viabler Zellen wurde mittels Trypanblauausschluß zu verschiedenen Zeitpunkten der Kultur ermittelt. Außerdem wurden die Zellen mittels Elektronenmikroskopie und Immuncytochemie untersucht. Die Befunde zeigen, daß die Zellen in der Kultur eine Veränderung ihres Phänotyps sowie funktionelle Änderungen im Sinne einer Ausreifung zu antigenpräsentierenden, T-Zell stimulierenden Zellen erfahren. Das in-vitro-Verhalten entspricht dem von Langerhanszellen in vivo nach Kontaktsensibilisierung. Mit Hilfe von eines für Apoptose spezifischen ELISA (= Enzyme-linked immunosorbent assay: eine Nachweisreaktion für Antigene bzw. Antikörper mithilfe von Enzymen) und Elektronenmikroskopie wurde nachgewiesen, daß die Zellen in unseren Kulturen durch Apoptose starben. Es gibt keinen Anhaltspunkt dafür, daß sich die Zellen nicht auch in vivo apoptotisch eliminieren. Die Verlauf der Funktionsmarker weist darauf hin, daß vorwiegend die maturierten Zellen von Apoptose betroffen waren, und die Apoptose über das CD 95/CD 95 L- System gesteuert wurde. Die Versuche zeigten insgesamt, daß Langerhanszellen durch Apoptose aus der Kultur eliminiert werden. Da sich die Zellen nach Migration in vitro wie Langerhanszellen nach Antigenpräsentation in vivo verhalten, scheint die Apoptose ein biologisches Regulativ für die Elimination von funktionell ausgereiften Langerhanszellen darzustellen. / This work describes the phenotypic behavior of cultivated Langerhans-cells, epidermal cells presenting antigenes and how they are eliminated . Therefore cultures of Langerhans-cells won by migration from normal human skin were used. The migrated Langerhans-cells have the same phenotypic features as Langerhans-cells after presentation of antigenes in situ. The aim of this work was to show the functional and cellular features of Langerhans-cells in culture and the way of their elimination. The cells still alive were count at distinct times using the Trypan-blue-exclusion-method. Additionally the cells were examined by electron microscopy and immuncytochemical methods. The findings show, that the cells in culture have the same characteristics of the phenotype and change of their function in the direction of developing to antigen-presenting, T-cell-stimulating cells. The in vitro behaviour is the same as of Langerhans-cells in vivo after contact-sensitization. With the help of an elisa (=Enzyme-linked immunosorbent assay) specific for apoptosis ( Cell Death Detection Elisa = CDDE) and with electron microscopy was shown, that the cultivated cells died by apoptosis. There is no reference point, that the cells do not do the same in vivo. The process of the functional markers shows, that predominantly the matured cells die by apoptosis and that it was controled by the CD 95/CD 95-L -system The investigations showed, that the Langerhans-cells were eliminated by apoptosis of the culture. The cells after migration in vitro behave in the same manner as after presentation of antigen in vivo. This indicates apoptosis to be the biologic regulation for the elimination of functional matured Langerhans-cells.
98

A formação da mineração urbana no Brasil: reciclagem de RCD e a produção de agregados. / The formation of urban mining in Brazil.

Lima, Francisco Mariano da Rocha de Souza 07 March 2013 (has links)
A nova Política Nacional de Resíduos Sólidos no Brasil, consubstanciada na lei 12305 /2010, possibilita o emprego de instrumentos econômicos para o fortalecimento de um mercado de agregados reciclados ainda nascente, no qual a maior parte dos resíduos de construção e demolição (RCD) ainda não é reciclada. Este trabalho tem fundamentos técnicos em duas áreas do conhecimento: a engenharia mineral e a construção civil. Na área mineral, será analisado o tratamento do RCD, processado como um minério. Na cadeia da construção civil, o foco é o uso dos agregados reciclados obtidos a partir dos resíduos da construção e demolição, que permite a valorização do RCD como insumo para estes agregados. O conceito de mineração urbana diz respeito à procura e ao processo de tratamento dos RCDs como matéria prima para o mercado de agregados reciclados que se formou no marco regulatório da resolução CONAMA 307 de 2002. Neste mercado de agregados reciclados nascente, usa-se o conceito de Indústria Recicladora Emergente para traçar as possíveis estratégias para alcançar o nível qualitativo dos produtos de indústrias recicladoras maduras, localizada nos países pós-industriais. Para dar conta da complexidade de ações da gestão dos RCDs no novo marco regulatório, empregou-se a modelagem dinâmica para os modelos de Custo Benefício em São Paulo, Macaé e Maceió e de Viabilidade da implantação de plantas de reciclagem na cidade de Macaé. A modelagem baseia-se no trabalho empírico de amostragem do RCD das três cidades brasileiras e em visitas a plantas de reciclagem no Brasil e no exterior. Os resultados obtidos mostram: 1) A heterogeneidade das cidades amostradas no tocante a qualidade do RCD originários de distintos processos de urbanização; 2) O modelo de Custo - Benefício para as três cidades mostra que os benefícios superam os custos na seguinte ordem: São Paulo, Macaé e Maceió; 3) Plantas móveis de reciclagem são mais viáveis do que as fixas na cidade de Macaé; 4) A região de São Paulo, devido ao maior volume de RCD e maiores estímulos à reciclagem, é a única entre as três que não precisa de subsídios; 5) O modelo de viabilidade mostra que a qualidade do resíduo tem considerável influência na viabilidade das empresas de reciclagem; 6) Os fatores mais sensíveis ao modelo de viabilidade são nesta ordem: o valor cobrado pelo terreno, a taxa cobrada na entrada do RCD na planta de reciclagem, os custos de operação da planta e os impostos em vigor. / The new National Policy of Solid Waste in Brazil (Política Nacional de Resíduos Sólidos) based on the law 12305/2010, allows the use of economic instruments for the strengthening of the market of recycled aggregates still nascent, where the major part of its construction and demolition waste (CD&W) is not recycled yet This work has technical roots in two knowledge fields: mining and construction. In the mining field it will be analyzed the CD&W treatment, processed as an ore. In the construction chain the focus will be at the application of the recycled aggregates obtained, that allows the valorization of the CD&W as a raw material of these aggregates. The concept of urban mining refers to the searching and the process of treating the CD&W as raw material for the market of recycled aggregates formed in the regulatory framework of CONAMA Resolution 307. In this nascent market for recycled aggregates we use the concept of recycling emerging industry and determined possible strategies to reach the quality level of the products of recycling industries located in mature post-industrial countries. To solve the complexity of the inherent management actions of CD&W in the new regulatory framework, it was employed dynamic modeling models of Cost Benefit analysis in Sao Paulo, Macaé and Maceió and also Feasibility models to implement recycling plants in the city of Macaé. The modeling is based on the empirical work of CD&W sampling of the three Brazilian cities and visits to recycling plants in Brazil and abroad. The results show: 1) The heterogeneity of the cities surveyed regarding the quality of the CD&W due to the different processes of urbanization; 2) The model of Cost - Benefit for the three cities shows that the benefits are greater than the costs in the following order: São Paulo, Macaé, Maceió; 3) In the city of Macaé, recycling mobile plants are more economic viable; 4) The region of Sao Paulo, due to higher volume and higher RCD incentives recycling, is the only one among the three which do not need subsidies; 5) The feasibility model shows that the difference in qualities of the waste has considerable influence on the viability of recycling companies; 6) The most sensitive factors in the viability model are in this order: the amount charged for the land, the tax fee into the recycling plant, the plant\'s operational costs and the taxes.
99

A survey of Compact Disc-Read Only Memory (CD-ROM) technology application in South African university libraries.

Munoo, Rajendra. January 2000 (has links)
This study surveyed Compact Disc-Read Only Memory (CD-ROM) technology in South African university libraries. The survey instrument used to elicit data was a questionnaire which was distributed via electronic mail (e-mail). CD-ROMs have been in the marketplace for over a decade and the extent to which South African university libraries have embraced CD-ROM technology was surveyed. Libraries offer CD-ROM services to internal staff and end-users, who in this study were students and academic staff. The study highlighted some of the CD-ROM related management issues such as budgeting, networking, resource sharing and end-user training. Survey results from the respondents indicated that they had all adopted CD-ROM technology. However, the level of CD-ROM technology and services in Historically White Institutions (HWI) and Historically Black Institutions (HBI) differed. This was evident in areas such as the year in which CD-ROMs were acquired, collection sizes and network access. The results showed that all libraries offered some form of enduser training to academic staff and students. The evolving nature of CD-ROM . technology presents a great challenge for libraries trying to keep up-to-date with the technology. This was highlighted in the open-ended questions about CD-ROM development plans and comments in general about CD-ROM technology in the different libraries. All libraries had access to the Internet and were working towards providing electronic information resources via the Web. Resource sharing and the establishment of consortiums can address the exorbitant costs of providing electronic information resources. Recommendations for further research on different aspects of CD-ROM technology were made. The development of the Internet as an information delivery system for the distribution of on-line information will emphasize the extent to which librarians and end-users are using the Internet for on-line information, as compared with CD-ROM services. Increasingly, aggregators are publishing information on the Internet and South African university libraries are already seeing this as an alternative to maintaining CD-ROM technology and services. / Thesis (M.I.S.)-University of Natal, Pietermaritzburg, 2000.
100

A formação da mineração urbana no Brasil: reciclagem de RCD e a produção de agregados. / The formation of urban mining in Brazil.

Francisco Mariano da Rocha de Souza Lima 07 March 2013 (has links)
A nova Política Nacional de Resíduos Sólidos no Brasil, consubstanciada na lei 12305 /2010, possibilita o emprego de instrumentos econômicos para o fortalecimento de um mercado de agregados reciclados ainda nascente, no qual a maior parte dos resíduos de construção e demolição (RCD) ainda não é reciclada. Este trabalho tem fundamentos técnicos em duas áreas do conhecimento: a engenharia mineral e a construção civil. Na área mineral, será analisado o tratamento do RCD, processado como um minério. Na cadeia da construção civil, o foco é o uso dos agregados reciclados obtidos a partir dos resíduos da construção e demolição, que permite a valorização do RCD como insumo para estes agregados. O conceito de mineração urbana diz respeito à procura e ao processo de tratamento dos RCDs como matéria prima para o mercado de agregados reciclados que se formou no marco regulatório da resolução CONAMA 307 de 2002. Neste mercado de agregados reciclados nascente, usa-se o conceito de Indústria Recicladora Emergente para traçar as possíveis estratégias para alcançar o nível qualitativo dos produtos de indústrias recicladoras maduras, localizada nos países pós-industriais. Para dar conta da complexidade de ações da gestão dos RCDs no novo marco regulatório, empregou-se a modelagem dinâmica para os modelos de Custo Benefício em São Paulo, Macaé e Maceió e de Viabilidade da implantação de plantas de reciclagem na cidade de Macaé. A modelagem baseia-se no trabalho empírico de amostragem do RCD das três cidades brasileiras e em visitas a plantas de reciclagem no Brasil e no exterior. Os resultados obtidos mostram: 1) A heterogeneidade das cidades amostradas no tocante a qualidade do RCD originários de distintos processos de urbanização; 2) O modelo de Custo - Benefício para as três cidades mostra que os benefícios superam os custos na seguinte ordem: São Paulo, Macaé e Maceió; 3) Plantas móveis de reciclagem são mais viáveis do que as fixas na cidade de Macaé; 4) A região de São Paulo, devido ao maior volume de RCD e maiores estímulos à reciclagem, é a única entre as três que não precisa de subsídios; 5) O modelo de viabilidade mostra que a qualidade do resíduo tem considerável influência na viabilidade das empresas de reciclagem; 6) Os fatores mais sensíveis ao modelo de viabilidade são nesta ordem: o valor cobrado pelo terreno, a taxa cobrada na entrada do RCD na planta de reciclagem, os custos de operação da planta e os impostos em vigor. / The new National Policy of Solid Waste in Brazil (Política Nacional de Resíduos Sólidos) based on the law 12305/2010, allows the use of economic instruments for the strengthening of the market of recycled aggregates still nascent, where the major part of its construction and demolition waste (CD&W) is not recycled yet This work has technical roots in two knowledge fields: mining and construction. In the mining field it will be analyzed the CD&W treatment, processed as an ore. In the construction chain the focus will be at the application of the recycled aggregates obtained, that allows the valorization of the CD&W as a raw material of these aggregates. The concept of urban mining refers to the searching and the process of treating the CD&W as raw material for the market of recycled aggregates formed in the regulatory framework of CONAMA Resolution 307. In this nascent market for recycled aggregates we use the concept of recycling emerging industry and determined possible strategies to reach the quality level of the products of recycling industries located in mature post-industrial countries. To solve the complexity of the inherent management actions of CD&W in the new regulatory framework, it was employed dynamic modeling models of Cost Benefit analysis in Sao Paulo, Macaé and Maceió and also Feasibility models to implement recycling plants in the city of Macaé. The modeling is based on the empirical work of CD&W sampling of the three Brazilian cities and visits to recycling plants in Brazil and abroad. The results show: 1) The heterogeneity of the cities surveyed regarding the quality of the CD&W due to the different processes of urbanization; 2) The model of Cost - Benefit for the three cities shows that the benefits are greater than the costs in the following order: São Paulo, Macaé, Maceió; 3) In the city of Macaé, recycling mobile plants are more economic viable; 4) The region of Sao Paulo, due to higher volume and higher RCD incentives recycling, is the only one among the three which do not need subsidies; 5) The feasibility model shows that the difference in qualities of the waste has considerable influence on the viability of recycling companies; 6) The most sensitive factors in the viability model are in this order: the amount charged for the land, the tax fee into the recycling plant, the plant\'s operational costs and the taxes.

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