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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

Att vara eller icke vara. Karriärvägledning inom Ilula FDC, Tanzania

Ahmeti, Valentina, Nyström, Ann-Christine January 2017 (has links)
Vårt valda undersökningsområde är Ilula Folk Development College, FDC, i Tanzania där det idag inte finns någon utbildad personal inom karriärvägledning. Ett problem som vi stött på under vår forskning om karriärvägledning i Tanzania är avsaknaden av utbildad personal, att området är relativt nytt och att det finns behov av mer forskning om det relativt outforskade området - karriärvägledning i Tanzania. Vi menar att det är av stor vikt att vi som framtida studie- och yrkesvägledare får ökad kunskap om vilka faktorer som påverkar elevers val av utbildning och yrke i andra kulturer, till exempel inom FDC i Tanzania, för att öka vår egen medvetenhet och för att bidra med nya fakta. Syftet med vår undersökning är att få en ökad kunskap om och förståelse för vilka faktorer som påverkar elever att påbörja en yrkesutbildning inom Ilula FDC i Tanzania, vilka tankar eleverna har kring framtida arbete efter avslutad yrkesutbildning samt vad eleverna själva önskar inom karriärvägledning. Våra frågeställningar är: Vilka faktorer har påverkat elever att påbörja en yrkesutbildning på Ilula FDC i Tanzania? Vilka tankar har eleverna på Ilula FDC i Tanzania kring framtida arbete efter avslutad yrkesutbildning? Vad anser eleverna som studerar en yrkesutbildning på Ilula FDC i Tanzania sig behöva inom karriärvägledning?Undersökningen är kvalitativ med halvstrukturerad intervjuguide och baseras på fem intervjuer. De teorier som används i vår undersökning är careershipteorin, humankapitalteorin, systemteori och teorin om socio-dynamisk vägledning. Begrepp som används är kapital, handlingshorisont, humankapital, påverkningsfaktorer, empowerment samt the joint action. Undersökningen visar att faktorer som påverkat respondenterna till att påbörja en yrkesutbildning på Ilula FDC är familj, vänner eller bekanta samt efterfrågan på arbetsmarknaden. Respondenterna i undersökningen har tankar kring att starta eget efter avslutade studier och samtliga respondenter önskar karriärvägledare på Ilula FDC.
2

TEDA : a Targeted Estimation of Distribution Algorithm

Neumann, Geoffrey K. January 2014 (has links)
This thesis discusses the development and performance of a novel evolutionary algorithm, the Targeted Estimation of Distribution Algorithm (TEDA). TEDA takes the concept of targeting, an idea that has previously been shown to be effective as part of a Genetic Algorithm (GA) called Fitness Directed Crossover (FDC), and introduces it into a novel hybrid algorithm that transitions from a GA to an Estimation of Distribution Algorithm (EDA). Targeting is a process for solving optimisation problems where there is a concept of control points, genes that can be said to be active, and where the total number of control points found within a solution is as important as where they are located. When generating a new solution an algorithm that uses targeting must first of all choose the number of control points to set in the new solution before choosing which to set. The hybrid approach is designed to take advantage of the ability of EDAs to exploit patterns within the population to effectively locate the global optimum while avoiding the tendency of EDAs to prematurely converge. This is achieved by initially using a GA to effectively explore the search space before transitioning into an EDA as the population converges on the region of the global optimum. As targeting places an extra restriction on the solutions produced by specifying their size, combining it with the hybrid approach allows TEDA to produce solutions that are of an optimal size and of a higher quality than would be found using a GA alone without risking a loss of diversity. TEDA is tested on three different problem domains. These are optimal control of cancer chemotherapy, network routing and Feature Subset Selection (FSS). Of these problems, TEDA showed consistent advantage over standard EAs in the routing problem and demonstrated that it is able to find good solutions faster than untargeted EAs and non evolutionary approaches at the FSS problem. It did not demonstrate any advantage over other approaches when applied to chemotherapy. The FSS domain demonstrated that in large and noisy problems TEDA’s targeting derived ability to reduce the size of the search space significantly increased the speed with which good solutions could be found. The routing domain demonstrated that, where the ideal number of control points is deceptive, both targeting and the exploitative capabilities of an EDA are needed, making TEDA a more effective approach than both untargeted approaches and FDC. Additionally, in none of the problems was TEDA seen to perform significantly worse than any alternative approaches.
3

Determining the role of follicular dendritic cells in TSE agent neuroinvasion

McCulloch, Laura January 2011 (has links)
Transmissible spongiform encephalopathies (TSEs), such as scrapie and variant Creutzfeldt-Jakob disease are infectious, fatal, neurodegenerative diseases. Following peripheral infection TSE agents usually accumulate in lymhoid tissues before spreading to the central nervous system. In mice, follicular dendritic cells (FDCs) expressing the host prion protein (PrPC) are essential for scrapie agent accumulation in lymphoid tissues. The accumulation of the scrapie agent on FDCs is critical for the efficient spread of infection to the brain. However, it is unknown whether FDCs themselves actively replicate the scrapie agent, or simply accumulate it following production by other cells types such as neurones, lymphocytes or other stromal cell populations. To definitively address this issue a transgenic mouse model was created in which PrPC is switched on or off exclusively on FDCs. Expression of cre-recombinase (Cre) under the action of cell-specific gene promoters can be used to induce or delete the expression of a target gene in specific cell populations. In this model, Cre expression is driven by the complement receptor type 2 gene (Cr2/CD21) which is expressed by FDCs and mature B lymphocytes. Characterisation of the CD21-cre mouse line was achieved by crossing with a ROSA26 reporter strain. The CD21-cre mouse line was subsequently crossed with floxed-PrP mouse lines to produce compound transgenic mouse lines in which PrPC expression was switched on or off, only in FDCs. Cre expression by B lymphocytes was eliminated by γ-irradiation and grafting recipient mice with Cre-deficient bone marrow. Immunohistochemical analysis confirmed the expression PrPC had been switched on or off exclusively on FDCs. Subsequently, the mice were challenged with scrapie by intra-peritoneal injection to determine the precise role of FDCs in the accumulation of scrapie in lymphoid tissues. Switching off PrPC expression exclusively on FDCs prevented the accumulation of TSE agent specific disease-associated PrPSc in the spleen after i.p inoculation. Conversely, in mice in which PrPC was expressed only on FDC, successful replication of the agent occurred on the FDC network in the spleen. Taken together, these data show PrPC-expressing FDCs alone are sufficient to support the accumulation of the scrapie agent within lymphoid tissues. Furthermore, these data suggest FDC replicate the TSE agent and do not simply accumulate it following synthesis by other cell types.
4

The design of an all-digital VCO-based ADC in a 65nm CMOS technology

Thangamani, Manivannan, Prabaharan, Allen Arun January 2014 (has links)
This thesis explores the study and design of an all-digital VCO-based ADC in a 65 nm CMOS technology. As the CMOS process enters the deep submicron region, the voltage-domain-based ADCs begins to suffer in improving their performance due to the use of complex analog components. A promising solution to improve the performance of an ADC is to employ as many as possible digital components in a time-domain-based ADC, where it uses the time resolution of an analog signal rather than the voltage resolution. In comparison, as the CMOS process scales down, the time resolution of an analog signal has found superior than the voltage resolution of an analog signal. In recent years, such time-domain-based ADCs have been taken an immense interest due to its inherent features and their design reasons. In this thesis work, the VCO-based ADC design, falls under the category of time-based ADCs which consists of a VCO and an appropriate digital processing circuitry. The employed VCO is used to convert a voltage-based signal into a time signal and thereby it also acts as a time-based quantizer. Then the resulting quantized-time signal is converted into a digital signal by an appropriate digital technique. After different architecture exploration, a conventional VCO-based ADC architecture is implemented in a high-level model to understand the characteristic behaviour of this time-based ADC and then a comprehensive functional schematic-level is designed in reference with the implemented behavioural model using cadence design environment. The performance has been verified using the mixed-levels, of transistor and behavioural-levels due to the greater simulation time of the implemented design. ADC’s dynamic performance has been evaluated using various experiments and simulations. Overall, the simulation experiments showed that the design was found to reach an ENOB of 4.9-bit at 572 MHz speed of sample per second, when a 120 MHz analog signal is applied. The achieved peak performance of the design was a SNR of 40 dB, SFDR of 34 dB and an SNDR of 31 dB over a 120 MHz BW at a 1 V supply voltage. Without any complex building blocks, this VCO-based all-digital ADC design provided a key feature of inherent noise shaping property and also found to be well compatible at the deep submicron region.
5

Využití prostředí Matlab Simulink při výuce Mechaniky letu II / Matlab Simulink for Flight Mechanics II module

Černota, Jiří January 2016 (has links)
The thesis is about the use of Matlab Simulink software for subject Flight Mechanics II. User interface, which allow computing of aerodynamic derivations and state space matrices, was created. It also provides system for launching simulations of longitudinal aircraft movement in Simulink environment and results visualization. In the last part were suggested examples for practice lessons of the aforementioned subject. These lessons focus on mastering basic block programming and to understand concept of aircraft dynamics and controlling aircraft movement.
6

Analysis and Modeling of Non-idealities in VCO-Based Quantizers Using Frequency-to-Digital and Time-to-Digital Converters

Yoder, Samantha 01 November 2010 (has links)
No description available.
7

Immunophänotypisierung des entzündlichen Infiltrates der Arthrose assoziierten Synovialitis

Ristow, Gerhard 07 April 2003 (has links)
Die Entzündungsreaktion der Arthrose wird als eine sekundäre Reaktion auf einen degenerativen Prozeß des Gelenkknorpels angesehen. Die Ursache für die Degeneration kann im Mißverhältnis zwischen Belastbarkeit und Beanspruchung liegen, es können metabolische Störungen (Urämie, Diabetes mellitus) verantwortlich gemacht werden, weswegen von sekundärer Arthrose gesprochen wird. Die Ursache der primären Arthrose bleibt unbekannt. Es kann als bewiesen angesehen werden der Zusammenhang mit Alter und Geschlecht der Patienten, denn Arthrose ist in der Regel eine Erkrankung jenseits des fünfzigsten Lebensjahres und betrifft vornehmlich Frauen. In der vorliegenden Arbeit wurde die Synovialis von 20 Patienten aufgearbeitet und hinsichtlich des enthaltenen entzündlichen Infiltrates untersucht. Unter Anwendung der indirekten Immunperoxidase Technik und der indirekten Immunfluoreszenz Technik wurde die Expression der Antigene CD 20, CD 23, CD 40, CD 27, IgG, IgA, IgM, Kappa, Lambda, CD 3, CD 4, CD 8, Ki M4, CD 68, Ki 67 sowie die Expression der Cytokine IL 2 und IL 10 analysiert. Die Synovialmembran zeigte histologisch eine Verbreiterung der Deckzellschicht, Knorpelfragmente innerhalb der Synovialmembran und ein insgesamt schwach ausgeprägtes entzündliches Infiltrat. In lediglich drei von 20 Fällen fand sich eine stärkere entzündliche Infiltration. Diese entzündlichen Infiltrate wiesen eine perivaskuläre Verteilung auf. Am häufigsten wurden in gefäßnahen Regionen B Lymphozyten identifiziert, Plasmazellen wiesen in der Regel einen deutlich größeren Abstand zum Gefäß auf. Unter den nachgewiesenen Plasmazellen fand sich eine prädominante Expression an IgG bei ausgewogener Anwesenheit sowohl der Kappa- als auch der Lambda- Leichtketten. T Lymphozyten waren ebenfalls zirkulär um die Gefäße anzutreffen und zeigten eine prädominante Interleukin 10 Expression. Lymphozytäre Aggregate, mit follikelähnlicher Struktur ließen sich in lediglich in 4 von 20 Fällen nachweisen. Makrophagen waren sowohl perivaskulär als auch in der Deckzellschicht nachweisbar. Ki M4 positive Retikulumzellen (FDC) waren dagegen nur in einem von 20 Fällen nachweisbar. Alle Zellpopulationen der Membrana synovialis wiesen nur eine schwache Proliferationsaktivität auf. Das Fehlen von dem Keimzentrum des Lymphfollikels vergleichbaren Strukturen, die deutliche Abwesenheit von Ki M4 positiver FDC's sowie die schwache Expression von Ki 67, sprechen trotz Anwesenheit der ebenfalls zur Antigenpräsentation befähigten Makrophagen gegen eine Einwanderung und Maturation nativer B Lymphozyten in die Membrana Synovialis. Wandern dagegen Gedächtniszellen in die Membrana synovialis ein, so ist eine Maturation mit Follikelbildung nicht mehr notwendig. Unter der Mithilfe von T Lymphozyten und Makrophagen können die B Lymphozyten zu Plasmazellen differenzieren. T Lymphozyten zeichnen sich ebenfalls durch eine starke perivaskuläre Verteilung aus. Dabei ist die Expression von IL 10 prädominant, was sich als eine Immunantwort von TH2-Typus interpretieren läßt. Diese ermöglicht eine Differenzierung der B Lymphozyten zu Plasmazellen. Reife B Lymphozyten, die unter dem Einfluß einer TH2 Subpopulation von CD 4 positiven T Lymphozyten ohne Keimzentrum zu Plasmazellen differenzieren, könnten ein Grund dafür sein, daß follikuläre Strukturen fehlen. Vorgereifte B Lymphozyten benötigen auch keine inflammatorisch hochpotenten Zytokine um eine schnelle Reifung und eine Immunantwort zu ermöglichen. Dies könnte ein Grund sein, warum die entzündliche Reaktion bei Arthrose so schwach ausgeprägt ist. / Inflammation in osteoarthritis is a secondary reaction to a degenerating process of the articular cartilage. Cause of Degeneration can be a disproportion of mechanical stress and resistance or metabolic diseases like diabetes mellitus. This kind of osteoarthritis is called "secondary osteoarthritis". Primary osteoarthritis has an unknown cause. Age and sex of the patient are a predictor for osteoarthritis, hense it is a disease of people above the age of 50 and more often it is found in women than in men. This paper investigated the synovial membranes of twenty patients to characterize the inflammatory Infiltrate. It characterized the cell surface antigen CD 20, CD 23, CD 40, CD 27, CD 3, CD 4, CD 8, Ki M4, CD 68, the antibodies IgG, IgA, IgM, Kappa, Lambda, the proliferating antigen Ki 67 and the expression profile of the cytokines IL 2 and IL 10 by using immunohistochemical staining (indirect immunoperoxidase technique and indirect immunofluorescence technique) with monoclonal antibodies. The synovial membrane shows in histology a dissemination of cover cells, fragments of cartilage and a slight expression of inflammatory infiltrate with a perivascular allocation. In only three of twenty cases we detected stronger inflammatory infiltrates. Most of the perivascular cells express CD 20. They are B lymphocytes. Plasma cells have more distance to the blood vessels and showed a predominant expression of IgG. T-lymphocytes were also detected perivascular. The expression of IL 10 was predominant. Lymphocytes aggregates like lymph follicle were detected in four of twenty cases. Macrophages were proved perivascular as well as in the cover cells. Ki M4 positive reticulum cells were found in only one of twenty cases. All kind of cells in the synovial membrane showed a low proliferation activity. The absence of germinal centers or comparable structures, the low expression of Ki M4 and Ki 67 speak against the immigration and maturation of native B lymphocytes in the synovial membrane. Memory B-lymphocytes don't need germinal centers or compatible structures for maturation, they can mature to plasma cells by help of T-lymphocytes, macrophages or other B-lymphocytes. It is more probably that the detected B lymphocytes are memory cells. The perivascular T lymphocytes in combination with the predominant expression of IL 10 may be interpreted as a TH2 immune reaction. This supports the maturation of B-lymphocytes to plasma cells. The maturation of memory B-lymphocytes under influence of TH2 immune reaction can be the reason for the missing of germinal centers or comparable structures. Matured B-lymphocytes don't need high-grade inflammatory cytokines for quick immune response. This is the possible reason for the low-grade inflammatory reaction of osteoarthritis.
8

Individualization of fixed-dose combination regimens : Methodology and application to pediatric tuberculosis / Individualisering av design och dosering av kombinationstabletter : Metodologi och applicering inom pediatrisk tuberkulos

Yngman, Gunnar January 2015 (has links)
Introduction: No Fixed-Dose Combination (FDC) formulations currently exist for pediatric tuberculosis (TB) treatment. Earlier work implemented, in the software NONMEM, a rational method for optimizing design and individualization of pediatric anti-TB FDC formulations based on patient body weight, but issues with parameter estimation, dosage strata heterogeneity and representative pharmacokinetics remained. Aim: To further develop the rational model-based methodology aiding the selection of appropriate FDC formulation designs and dosage regimens, in pediatric TB treatment. Materials and Methods: Optimization of the method with respect to the estimation of body weight breakpoints was sought. Heterogeneity of dosage groups with respect to treatment efficiency was sought to be improved. Recently published pediatric pharmacokinetic parameters were implemented and the model translated to MATLAB, where also the performance was evaluated by stochastic estimation and graphical visualization. Results: A logistic function was found better suited as an approximation of breakpoints. None of the estimation methods implemented in NONMEM were more suitable than the originally used FO method. Homogenization of dosage group treatment efficiency could not be solved. MATLAB translation was successful but required stochastic estimations and highlighted high densities of local minima. Representative pharmacokinetics were successfully implemented. Conclusions: NONMEM was found suboptimal for the task due to problems with discontinuities and heterogeneity, but a stepwise method with representative pharmacokinetics were successfully implemented. MATLAB showed more promise in the search for a method also addressing the heterogeneity issue.

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