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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.
1

Characterisation of a novel leukocyte receptor complex-encoded receptor TARM1

Radjabova, Valeria January 2018 (has links)
Cellular immune responses are orchestrated by an intricate balance of activating and inhibitory signals transmitted by cell surface receptors. Perturbations in this balance by overamplified or dysregulated signalling underlie many severe immunopathologies such as sepsis and cancer. In this work I describe the identification and characterisation of a novel, evolutionarily conserved immunoreceptor encoded within the human leukocyte receptor complex and syntenic region of mouse chromosome 7, named T cell-interacting, activating receptor on myeloid cells-1 (TARM1). The transmembrane region of TARM1 contained a conserved arginine residue, consistent with association with a signalling adaptor. Co-immunoprecipitation experiments confirmed that TARM1 associated with the ITAM adaptor FcR-gamma but not with DAP10 or DAP12. Flow cytometric screening of cells and tissues from pathogen-free mice showed that the TARM1 protein was constitutively expressed on the cell surface of mature and immature CD11b+Gr+ neutrophils isolated from bone marrow but not at peripheral sites. Following ip LPS treatment or systemic bacterial challenge, TARM1 protein expression was upregulated by myelocytes, mature neutrophils and inflammatory monocytes and TARM1+ cells were rapidly recruited to sites of inflammation. TARM1 expression was also upregulated by bone marrow-derived macrophages and dendritic cells following stimulation with TLR agonists in vitro. Ligation of the TARM1 receptor with specific antibody in the presence of TLR ligands, such as LPS, enhanced the secretion of proinflammatory cytokines by bone marrow-derived macrophages and primary mouse neutrophils, whereas TARM1 stimulation alone had no effect. Finally, an immobilised TARM1 Fc fusion protein suppressed CD4+ T cell activation and proliferation in vitro. These results suggest that a putative T cell ligand can interact with TARM1 receptor, resulting in bidirectional signalling and raising the T cell activation threshold while costimulating the release of proinflammatory cytokines by macrophages and neutrophils.
2

Estudo da parametrização de funcionais LRC aplicados a propriedades ópticas de carotenóides

Prado, Andriele da Silva 27 August 2014 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Física, 2014. / Submitted by Ana Cristina Barbosa da Silva (annabds@hotmail.com) on 2014-10-30T15:56:10Z No. of bitstreams: 1 2014_AndrieledaSilvaPrado.pdf: 8852957 bytes, checksum: 80aecac6a1429a718497b4476a6c86e8 (MD5) / Approved for entry into archive by Tania Milca Carvalho Malheiros(tania@bce.unb.br) on 2014-10-31T13:25:16Z (GMT) No. of bitstreams: 1 2014_AndrieledaSilvaPrado.pdf: 8852957 bytes, checksum: 80aecac6a1429a718497b4476a6c86e8 (MD5) / Made available in DSpace on 2014-10-31T13:25:16Z (GMT). No. of bitstreams: 1 2014_AndrieledaSilvaPrado.pdf: 8852957 bytes, checksum: 80aecac6a1429a718497b4476a6c86e8 (MD5) / É conhecido que as energias de gap de sistemas moleculares calculadas através da resolução da equação de Kohn-Sham com funcionais convencionais da Teoria do funcional da Densidade são geralmente muito pequenas quando comparadas com os valores de gap obtidos experimentalmente. Esses erros indicam uma clara falha dos funcionais aproximados frequentemente usados na DFT e podem, muitas vezes, nos levar a interpretações erradas a respeito das propriedades ópticas de tais sistemas. Esse trabalho propõe uma nova metodologia de parametrização de funcionais que incluem diferentes correções de longo alcance, dedicadas às moléculas dos principais carotenóides presentes no óleo de Buriti. Esses funcionais contemplam 100% da troca exata de Hartree-Fock, um operador não local extremamente importante para uma descrição mais realista das energiasHOMO-LUMO e outras propriedades de estado excitado. O grupo de carotenóides estudado tem alto potencial de aplicação em dispositivos fotovoltaicos orgânicos, e tem sido intensamente explorado tanto do ponto de vista teórico quanto experimental. ______________________________________________________________________________ ABSTRACT / It is known that the energy gap of molecular systems calculated by solving theKohn-Sham equation with conventional of Density Functional Theory functional are usuallysmall compared to the values gap obtained experimentally. These errors indicate aclear failure of the approximate functional often used in DFT, and can often lead us tomisinterpretations regarding the optical properties of such systems. This work proposesa new methodology for functional parameterization that include long-range corrections,dedicated to the molecules of the main carotenoids present in Buriti Oil. Such functionalcontains 100 % of the exact Hartree-Fock exchange, a non-local operator extremely importantfor a realistic descriptionenergies of HOMO-LUMO and other properties of theexcited state. The group of carotenoids investigated has high potential for applicationin organic photovoltaic devices and has been extensively explored both theoretically andexperimentally.
3

Genetische Charakterisierung des "Leukocyte Receptor Complex" und Entwicklung einer Methode zum Nachweis seiner Produkte im Einzelzellmaßstab

Wende, Hagen January 2003 (has links)
Der "Leukocyte Receptor Complex" (LRC) ist ein DNA-Sequenzabschnitt auf dem Chromosom 19 des Menschen, der eine Länge von über 900.000 Basenpaaren umfaßt. In diesem Chromosomenabschnitt ist eine Vielzahl von Genen lokalisiert, die für die Funktion verschiedener weißer Blutzellen (Leukozyten) von entscheidender Bedeutung sind. Bei den aus diesen Genen synthetisierten Proteinen (Eiweißen) handelt es sich um Strukturen, die auf der Oberfläche dieser Zellen lokalisiert sind und zur Interaktion der Leukozyten mit ihrer Umgebung dienen. Diese auch als Rezeptoren bezeichneten Proteine können mit Oberflächenproteinen auf anderen Körperzellen wechselwirken und daraus resultierende Signale in das Innere der Blutzelle weiterleiten. <br /> In der vorliegenden Doktorarbeit wurde der LRC im Detail untersucht. Hierzu wurde zunächst der gesamte Chromosomenabschnitt aus kleineren, einander überlappenden DNA-Fragmenten rekonstruiert. Aufgrund der in diesen DNA-Fragmenten enthaltenen DNA-Sequenzen war es möglich, den gesamten Chromosomenabschnitt ähnlich einem Puzzle zusammenzusetzen. Die anschließende Analyse des LRC zeigte, daß sich dieser in drei Bereiche, sogenannte Cluster, unterteilen läßt. Diese Cluster sind dadurch gekennzeichnet, daß in ihnen jeweils nur Gene eines Rezeptortyps vorkommen. Hierbei handelt es sich um ‚immunoglobulin-like transcript′ -Gene (ILT) und ‚killer cell Ig-like receptor′-Gene (KIR). Die KIR- und ILT-Cluster werden von weiteren stammesgeschichtlich verwandten Genen unterbrochen und flankiert. Je nach Individuum können im LRC bis zu 31 solcher verwandten Rezeptorgene lokalisiert sein. Auf der Grundlage der Kartierungsdaten und von Daten des humanen Genomprojekts war es zudem möglich, evolutionäre Untersuchungen zur Entwicklung des LRC durchzuführen. Dabei wurde eine Hypothese zur Entstehung des LRC entworfen und zu anderen Spezies in Beziehung gesetzt. <br /> Im zweiten Teil der Arbeit habe ich aufbauend auf der sogenannten HRCA-Methode eine Technik entwickelt, die es erlaubt kleinste Unterschiede zwischen DNA-Sequenzen, sogenannte Einzelbasenpaaraustausche, nachzuweisen. Die entwickelte Methode kann verwendet werden, um sehr ähnliche DNA-Sequenzen, wie z.B. verschiedene KIR-Sequenzen, zu unterscheiden und ihre Menge zu bestimmen. Sie ist außerdem geeignet Mutationen, die mit bestimmten Krankheiten assoziiert sind, nachzuweisen und könnte somit in der Diagnostik Anwendung finden. / The Leukocyte Receptor Complex (LRC) is a DNA region on human chromosome 19 with a length of approximately 900.000 base pairs. A number of genes, which are located in this chromosomal region, are known to be important for the function of some types of white blood cells (leukocytes). The products of theses genes are proteins, which are located on the surface of these cells and enable them to interact with their environment. These proteins are also called receptors. They can bind to cell surface proteins on other cells and transmit resulting signals into the leukocyte. <br /> During my work I analyzed the chromosomal organization of the LRC in detail. To do so, I reconstructed the whole chromosomal region from smaller overlapping DNA fragments. Due to the DNA sequences contained within these fragments it was possible to put the whole chromosomal region together like a puzzle. The following analyses of the LRC showed that it is mainly composed of three regions, so called clusters. These clusters are characterised by the presence of only one receptor family. These are the immunoglobulin-like transcripts (ILTs) and the killer cell Ig-like receptors (KIR) respectively. In the LRC the KIR- and ILT-Clusters are flanked by additional receptor genes, which are evolutionary related to KIRs and ILTs. The number of receptor genes in the LRC varies between individuals, their can be up to 31 genes on each chromosome. <br /> On the basis of the data obtained in this work as well as data from the human genome project it was also possible to draw conclusions concerning the evolutionary development of the LRC. I developed a hypothesis of the origin of the LRC and discussed this in comparison to other species. <br /> In the second part of my thesis I developed a new technique based on the so-called ’hyper-branched rolling circle amplification′ (HRCA). This technique allows the detection of small differences between two or more DNA molecules, so called ’single nucleotide polymorphisms′ (SNPs). With this newly developed method it is possible to distinguish very similar variants of a gene, e.g. two KIR sequences, and to determine their relative concentration. The method can also be used to detect mutations, which are associated with certain diseases and could therefore be used for diagnostic purposes.
4

Learning Resource Centre (LRC) : en bibliotekstrend? / Learning Resource Centre (LRC) : a library trend?

Sundberg, Linda January 2008 (has links)
Learning Resource Centre, or LRC, is an international phenomenon and a response to the changing society that came with the development of information technology. The LRC concept spread internationally during the 1990s and began to influence Swedish collage libraries at the end of the decade. The main purpose of this study is to analyze if and how Swedish college libraries have incorporated the LRC concept. Is there a Swedish LRC model? Is the LRC concept still interesting or was it a trend that is now out of date? Interviews with eleven people from six college libraries aim to show how they define the concept LRC and how it has been integrated in to their organisations. In order to explain how these six collage libraries have related to and developed their own LRC concept an organisational theory with a mythical perspective has been used. This perspective is related to an institutional perspective and is presented by the Norwegian professors Tom Christensen, Per Lægreid, Paul G. Roness and Kjell Arne Røvik in Organisationsteori i offentlig sektor. This study concludes that there is no Swedish model, however there are some undeniably Swedish characteristics. The concept LRC is never or seldom used and the activities connected to LRC have become ordinary activities at college libraries. The substance of the LRC remains and has improved the chances for use of and collaboration within the organisation. / Uppsatsnivå: D
5

Improvements to wireless, passive sensors for monitoring conditions within reinforced concrete structures

Chou, Chih-Chieh 20 December 2010 (has links)
The corrosion of steel reinforcement in reinforced concrete structures constitutes an alarming problem. To combat this problem, researchers at the University of Texas at Austin developed two, low-cost, passive, wireless sensors: a threshold, corrosion sensor and an analog conductivity sensor. Today, the basic circuit designs for both sensors are finished and their reliabilities are confirmed. However, multiple problems regarding the durability of the sensors remain. This research project: (a) identifies these problems, (b) proposes enhancements for each type of passive, wireless sensor, (c) tests and evaluates the proposed modifications to the sensors, and (d) proposes potential improvements and areas of research regarding the future development of these two sensors. / text
6

Design and Rapid-prototyping of Multidimensional-DSP Beamformers Using the ROACH-2 FPGA Platform

Seneviratne, Vishwa January 2017 (has links)
No description available.
7

A critical analysis of the learning culture of resilient schools within rural communities in Mpumalanga

Dlamini, Mathokoza James 30 June 2004 (has links)
The purpose of this study was to investigate those aspects of resilient schools which are particularly beneficial for schools within rural communities in Mpumalanga. The study was done in two phases: a literature review focussing on the culture of learning of resilient schools and an empirical investigation focussing on the culture of learning of resilient schools within rural communities in Mpumalanga. Two secondary schools were selected according to criteria of resiliency. The study involved qualitative approaches, in-depth observations and interviews with key informants: principals, teachers, learners and members of the school governing bodies. The data demonstrate that there is no distinctive aspect of the culture of learning of resilient schools because all aspects are interrelated and interdependent. This study discovered that the most effective aspect, which benefits the culture of teaching and learning in resilient schools, was the involvement of all stakeholders. / Educational Management / M.Ed.
8

A critical analysis of the learning culture of resilient schools within rural communities in Mpumalanga

Dlamini, Mathokoza James 30 June 2004 (has links)
The purpose of this study was to investigate those aspects of resilient schools which are particularly beneficial for schools within rural communities in Mpumalanga. The study was done in two phases: a literature review focussing on the culture of learning of resilient schools and an empirical investigation focussing on the culture of learning of resilient schools within rural communities in Mpumalanga. Two secondary schools were selected according to criteria of resiliency. The study involved qualitative approaches, in-depth observations and interviews with key informants: principals, teachers, learners and members of the school governing bodies. The data demonstrate that there is no distinctive aspect of the culture of learning of resilient schools because all aspects are interrelated and interdependent. This study discovered that the most effective aspect, which benefits the culture of teaching and learning in resilient schools, was the involvement of all stakeholders. / Educational Management / M.Ed.
9

Hydrogen Production and Storage Optimization based on Technical and Financial Conditions : A study of hydrogen strategies focusing on demand and integration of wind power. / Optimering av vätgasproduktion och lagring utifrån tekniska och ekonomiska förutsättningar : En studie av vätgasstrategier med fokus på efterfrågan och integration av vindkraft.

Langels, Hanna, Syrjä, Oskar January 2021 (has links)
There has recently been an increased interest in hydrogen, both as a solution for seasonal energy storage but also for implementations in various industries and as fuel for vehicles. The transition to a society less dependent on fossil fuels highlights the need for new solutions where hydrogen is predicted to play a key role. This project aims to investigate technical and economic outcomes of different strategies for production and storage of hydrogen based on hydrogen demand and source of electricity. This is done by simulating the operation of different systems over a year, mapping the storage level, the source of electricity, and calculating the levelized cost of hydrogen (LCOH). The study examines two main cases. The first case is a system integrated with offshore wind power for production of hydrogen to fuel the operations in the industrial port Gävle Hamn. The second case examines a system for independent refueling stations where two locations with different electricity prices and traffic flows are analyzed. Factors such as demand, electricity prices, and component costs are investigated through simulating cases as well as a sensitivity analysis. Future potential sources of income are also analyzed and discussed. The results show that using an alkaline electrolyzer (AEL) achieves the lowest LCOH while PEM electrolyzer is more flexible in its operation which enables the system to utilize more electricity from the offshore wind power. When the cost of wind electricity exceeds the average electricity price on the grid, a higher share of wind electricity relative to electricity from the grid being utilized in the production results in a higher LCOH. The optimal design of the storage depends on the demand, where using vessels above ground is the most beneficial option for smaller systems and larger systems benefit financially from using a lined rock cavern (LRC). Hence, the optimal design of a system depends on the demand, electricity source, and ultimately on the purpose of the system. The results show great potential for future implementation of hydrogen systems integrated with wind power. Considering the increased share of wind electricity in the energy system and the expected growth of the hydrogen market, these are results worth acknowledging in future projects.

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