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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.
371

Effects of Gate Stress and Parasitic Package Inductance on the Reliability of GaN HEMTs

Tine, Cheikh Abdoulahi, Tine January 2017 (has links)
No description available.
372

Study of Parasitic Barriers in SiGe HBTs Due to P-n Junction Displacement and Bias Effects

Mathur, Nitish 11 October 2001 (has links)
No description available.
373

Additions on historical buildings: The Malmö City- and Garage Library

Mohamad, Zahra, Krabbe, Christfel January 2024 (has links)
This study takes an in-depth look at the architectural journey of the Malmö City Library, paying particular attention to how traditional and modern architectural styles have merged together. We'll closely examine the contributions of architects like John Smedberg and Henning Larsen, who have played pivotal roles in shaping the library's visual identity. Throughout our exploration, we'll unpack key architectural concepts such as architectural rhythm, design contrast, and the principles of parasitic and prosthetic architecture. These concepts will serve as our guideposts as we navigate the complexities of integrating old and new architectural elements seamlessly. By analyzing real-world examples from the Malmö City Library, we'll gain valuable insights into the strategies employed by architects to achieve this harmony. At the core of our investigation lies a quest to understand the transformative power of thoughtful design. The Malmö City Library stands as a testament to this power, offering a tangible example of how architectural innovation can create spaces that are both functional and aesthetically pleasing. By examining the historical context and contemporary practices surrounding the library's evolution, we'll uncover the profound impact that architecture can have on our lived experiences. One of the key takeaways from our study is the importance of architectural adaptation. Through careful analysis, we'll uncover the challenges faced by architects as they sought to blend tradition with innovation. By studying the successes and failures of projects like the Malmö City Library, we'll gain a deeper understanding of the strategies that underpin successful architectural transformations. Ultimately, our research aims to contribute to a greater understanding of the role of architecture in shaping our built environment. By shining a spotlight on the architectural evolution of the Malmö City Library, we hope to inspire future generations of architects to approach their work with creativity, sensitivity, and a deep appreciation for the transformative potential of design. With this essay we will also be crafting a project proposal based on our comprehensive study and research into the topic of additions on existing buildings. Our focus will be on expanding the library Garaget, employing our expertise in the field and aligning with the specific needs of the library. Through this endeavor, we aim not only to enhance the Garaget library but also to promote its significance within the community in the area.
374

Detecting and characterizing the highly divergent plastid genome of the nonphotosynthetic parasitic plant Hydnora visseri (Hydnoraceae)

Naumann, Julia, Der, Joshua P., Wafula, Eric K., Jones, Samuel S., Wagner, Sarah T., Honaas, Loren A., Ralph, Paula E., Bolin, Jay F., Maass, Erika, Neinhuis, Christoph, Wanke, Stefan, dePamphilis , Claude W. 08 June 2016 (has links) (PDF)
Plastid genomes of photosynthetic flowering plants are usually highly conserved in both structure and gene content. However, the plastomes of parasitic and mycoheterotrophic plants may be released from selective constraint due to the reduction or loss of photosynthetic ability. Here we present the greatly reduced and highly divergent, yet functional, plastome of the nonphotosynthetic holoparasite Hydnora visseri (Hydnoraceae, Piperales). The plastome is 27 kb in length, with 24 genes encoding ribosomal proteins, ribosomal RNAs, tRNAs and a few non-bioenergetic genes, but no genes related to photosynthesis. The inverted repeat and the small single copy region are only ~1.5 kb, and intergenic regions have been drastically reduced. Despite extreme reduction, gene order and orientation are highly similar to the plastome of Piper cenocladum, a related photosynthetic plant in Piperales. Gene sequences in Hydnora are highly divergent and several complementary approaches using the highest possible sensitivity were required for identification and annotation of this plastome. Active transcription is detected for all of the protein coding genes in the plastid genome, and one of two introns is appropriately spliced out of rps12 transcripts. The whole genome shotgun read depth is 1,400X coverage for the plastome, while the mitochondrial genome is covered at 40X and the nuclear genome at 2X. Despite the extreme reduction of the genome and high sequence divergence, the presence of syntenic, long transcriptionally-active open reading frames with distant similarity to other plastid genomes and a high plastome stoichiometry relative to the mitochondrial and nuclear genomes suggests that the plastome remains functional in Hydnora visseri. A four stage model of gene reduction, including the potential for complete plastome loss, is proposed to account for the range of plastid genomes in nonphotosynthetic plants.
375

Factors affecting the performance of Pochonia chlamydosporia as a biological control agent for nematodes

Esteves, Ivania January 2007 (has links)
The work developed in this thesis aimed to increase understanding about the variability and stability in eleven biotypes of Pochonia chlamydosporia, a facultative parasitic fungus with potential as a biological control agent against root-knot (Meloidogyne spp.), false root-knot (Naccobus spp.) and cyst nematodes (Heterodera and Globodera, spp.). Differences in performance were assessed by measuring saprophytic and parasitic growth using in vitro bioassays. Information on virulence (in vitro) was collected for a range of biotypes with the objective to relate in vitro parasitic growth with rhizosphere colonisation ability and secretion of extracellular enzymes. Results showed differences between biotypes in their ability to colonise the rhizosphere of plants, parasitise nematode eggs and to produce a range of extracellular enzymes but no significant relationships were found between saprophytic or parasitic growth and enzyme production. For the first time, the specific activity of protease, chitinase, esterase and lipase enzyme production by eleven biotypes of the fungus was examined. Enzymatic activity was shown to vary with the biotype and type of enzyme assayed and biotypes could be ranked according to their similarities in enzyme production A novel bioassay to estimate egg parasitism using liquid media highlighted the importance of nutrition in infection processes and suggested that all biotypes are able to infect large numbers of eggs rapidly if the conditions are favourable. The assay reliably detected fungal infection in nematode eggs within 48 hours and provided a simple, rapid assay to test the effect of specific nutrients at controlled concentrations on the infection process. Differences in infection rates between biotypes observed in previous tests on agar were not detected in the new assay in which nematode eggs and fungal conidia were added in suspension. Internal colonisation of individual whole Meloidogyne spp. eggs by P. chlamydosporia was observed using microscopy studies. The destruction of nematode eggs infected with the fungus within seven days, was confirmed. The in vitro formation of appressoria was studied in a range of P. chlamydosporia biotypes. for the first time. Biotypes were found to differ in their ability to produce appressoria but this ability was not related to differences in virulence (in vitro) against nematode eggs. Cont/d.
376

The Other Side of the Fence

Jones, Benjamin S 01 January 2006 (has links)
I pull from what I see in my urban surroundings. There is always a sense of dread fused with optimism that prevails. Is it beautiful? Fragments of low-riders and tricked-out cars become symbols of desire and the glowing red lens of a stop light becomes a Cyclops poised to defend his garden. Candy-coated, blooming, dripping and seductively slick confronts you with the obvious warning: STOP! You could be next… …The grass really is greener on The Other Side of the Fence. At least until winter comes.
377

ANALYSIS OF HUMORAL IMMUNE RESPONSES IN HORSES WITH EQUINE PROTOZOAL MYELOENCEPHALITIS

Angwin, Catherine-Jane 01 January 2017 (has links)
Equine protozoal myeloencephalitis (EPM), caused by the protozoan parasite Sarcocystis neurona, is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1% of infected horses. Factors governing the occurrence and severity of EPM are largely unknown, although horse immunity might play an important role in clinical outcome. We hypothesize that EPM occurs due to an aberrant immune response, which will be discernable in the equine IgG subisotypes a, b, and (T) that recognize S. neurona in infected diseased horses versus infected but clinically healthy horses. Based on previously-established serum antibody concentrations for IgG subisotypes in healthy horses, standard curves were generated and served to establish the concentration of antigen-specific IgG subisotypes in equine serum and CSF in infected diseased and infected normal horses. The subisotype concentrations and ratios between subisotypes were analyzed to assess whether neurological disease is associated with detectable differences in the antibody response elicited by infection. Results indicate a type I biased immune response in infected diseased horses, implicating the role of immunity in the development of EPM.
378

Modélisation mathématique des dynamiques hôtes-parasites ; de l’écologie parasitaire à l’écologie du génome / Mathematical modeling of host-parasite dynamics; from parasite ecology to genome ecology

Flores Ferrer, Alheli 14 June 2019 (has links)
Ce document est dédié à la modélisation dynamique des interactions hôtes-parasites. Il porte sur deux modèles biologiques très différents, mais étudiés à l’aide de modèles épidémiologiques standards construits à partir de systèmes dynamiques à compartiments. La première contribution est l’implémentation d’un modèle ‘micro-parasites’ pour étudier la transmission du parasite protozoaire Trypanosoma cruzi, agent étiologique de la trypanosomiase américaine (ou ‘maladie de Chagas’), au sein d’une communauté d’hôtes synanthropiques et domestiques. L’analyse du modèle mathématique montre pour la première fois dans ce système biologique un effet de dilution associé aux hôtes aviaires, ainsi que la possibilité de réduire la transmission à l’homme par modification de la composition de la communauté d’hôtes domestiques. La seconde contribution porte sur la dynamique des ‘parasites génomiques’ que sont les éléments transposables. En utilisant les analogies entre concepts de génomique et d’écologie proposées par l’approche d’ « Écologie du génome », il a été possible d’adapter des modèles développés pour les ‘macro-parasites’ à la dynamique d’éléments transposables de classe 1, les retro-transposons. L’analyse de cesmodèles permet de formuler des hypothèses sur l’importance relative de la démographie des hôtes, de la distribution du nombre de copies entre les individus et des mécanismes moléculaires de silencing de ces éléments, sur leurpersistance au sein de population d’hôtes se reproduisant de façon asexuée. / This document is dedicated to the dynamic modeling of host-parasite interactions. It is about two distant biological models, who are studied using standard epidemiological models built from dynamic compartmental models. The first contribution is the implementation of a 'micro-parasites' model to study the transmission of the protozoan parasite Trypanosoma cruzi, the etiological agent of American trypanosomiasis (or 'Chagas' disease), within a host community of synanthropic and domestic animals. The analysis of the mathematical model shows for the first time in this biological system a dilution effect associated with avian hosts, as well as the possibility of reducing the transmission to humans by modifying the composition of the domestic host communities. The second contribution deals with the dynamics of the "genomic parasites" that are the transposable elements. Using the analogies between genomics and ecology concepts proposed by the "Genome Ecology" approach, it was possible to adapt models developed for 'macro-parasites' to the dynamics of transposable elements of class 1, retro-transposons. The analysis of these models makes it possible toformulate hypotheses on the relative importance of the host demography, the distribution of the number of copies between individuals and the molecular mechanisms of silencing of these elements, on their persistence within the population of hosts reproducing asexually.
379

Etudes physiologiques et comportemenales de la fertilité mâle chez un hyménoptère parasitoïdique, nasonia vitripennis / Physiologycal and behavioral studies on male fertility in a parasitoid wasp, Nasonia vitripennis

Chirault, Marlène 09 December 2015 (has links)
La plupart des études sur l’influence de la température sur la production des spermatozoïdes portent en grande partie sur les vertébrés. Néanmoins, les invertébrés constituent la majorité de la biodiversité terrestre animale, sont également plus sensibles à ces variations de température. Les travaux réalisés au cours de cette thèse ont porté sur la compréhension des capacités de reproduction, et sur l’influence d’une augmentation de température sur les fonctions mâles chez Nasonia vitripennis, un hyménoptère parasitoïde. Ce travail de thèse m’a permis de confirmer que chez cette espèce, la spermatogenèse était synchronisée et de décrire pour la première fois, un système de stockage intermédiaire des spermatozoïdes entre les testicules et les vésicules séminales. De plus, j’ai pu mettre en évidence que la spermatogénèse était sensible à une augmentation de température pendant le développement, altérant le sexe ratio de la descendance par des modifications d’allocations des sexes par les femelles. Ces résultats apportent de nouvelles connaissances sur la fertilité mâle chez cette espèce et démontrent la sensibilité de la spermatogenèse à la température. / Many studies on the impact of the temperature on spermatogenesis have largely focused on vertebrates. Nevertheless, invertebrates constitute the vast majority of terrestrial biodiversity, and are especially vulnerable to variations of temperatures. The studies realized during my thesis are focused on understanding male reproductive capacities and effects of heat stress on male fertility in a parasitic wasp Nasonia vitripennis. This work allowed to confirm that spermatogenesis was synchronized, and to describe for the first time a system of spermatozoa regulation between testis and seminal vesicles. Moreover, I was able to demonstrate that spermatogenesis was sensible to temperature variation during male development, and the offspring sex ratio was altered by modifications of sex allocation. These findings open the way to the description of male fertility in this species, and show the sensitivity of spermatogenesis to temperature variation.
380

Caracterização da resposta inflamatória induzida por Escherichia coli enteroinvasora (EIEC) e Shigella flexneri em células epiteliais intestinais da linhagem Caco-2 / Characterization of the inflammatory response induced by Escherichia coli enteroinvasive (EIEC) and Shigella flexneri in intestinal epithelial cells of the Caco-2 lineage

Ferreira, Lucas Gonçalves 05 September 2008 (has links)
Escherichia coli enteroinvasora (EIEC) e Shigella sp causam disenteria bacilar que é caracterizada pela invasão e destruição da mucosa do cólon humano. Amostras de EIEC possuem características bioquímicas, genéticas patogênicas semelhantes às espécies de Shigella, porém a doença causada por EIEC se apresenta numa forma mais branda e autolimitante. As células do epitélio intestinal participam ativamente da imunidade da mucosa, expressando e secretando uma série de mediad ores inflamatórios como citocinas, quimiocinas, moléculas de adesão e óxido nítrico. Para melhor entendimento da patogênese de EIEC, estudamos a resposta inflamatória modulada por este microrganismo em células epiteliais intestinais da linhagem Caco-2, comparando-a com Shigella flexneri. Células Caco-2 foram infectadas com EIEC ou S. flexneri por diferentes intervalos de tempo, para posterior analise da capacidade de invasão e disseminação bacterianas (UFC, PLAQUE ASSA Y), indução de morte celular (FACS), analise relativa de genes envolvidos no reconhecimento bacteriano e na resposta inflamatória (RT-PCR, RPA), dosagem de citocinas e quimiocinas pró-inflamatórias (ELISA) e óxido nítrico (GRIESS). Neste trabalho foi possível observar que: (i) a capacidade de disseminação e (ii) a indução da morte celular em células Caco-2 foi significativamente maior na infecção por S. flexneri do que EIEC; (iii) há diferenças em relação à expressão relativa de genes das células Caco-2 envolvidos no reconhecimento das duas cepas bacterianas. Foi evidenciado o papel essencial dos receptores intracelulares no reconhecimento bacteriano das células Caco-2, sendo a expressão relativa do mRNA do receptor intracelular Nod1 foi maior para EIEC quando comparado com S. flexneri; (iv) há diferenças significativas na cinética de produção de NO pelas células Caco¬2 infectadas, em que EIEC induziu mais precocemente a produção de NO quando comparado com S. flexneri. Estes dados sinalizam que as células epiteliais intestinais reconhecem e respondem de forma diferente frente a essas duas espécies bacterianas, apresentando uma resposta inflamatória mais eficiente no controle da infecção induzida por EIEC. / Escherichia coli enteroinvasive (EIEC) and Shigella sp cause bacillary dysentery which is characterized by the invasion and destruction of the human colon mucosa. Samples of EIEC have characteristics biochemical, genetic and pathogenic similar to those of Shigella species, however the disease caused by EIEC is more lenient. The cells of the intestinal epithelium actively participate in the mucosal immunity by expression and production of several inflammatory mediators such as cytokines, chemokines, adhesion molecules and nitric oxide. For better understanding of the EIEC pathogenesis, we studied the inflammatory response modulated by this microorganism in intestinal epithelial cells Caco-2, comparing it with Shigella flexneri. Caco-2 cells were infected with EIEC or S. flexneri during different intervals of time and analyzed the invasiveness and spread bacteria capacity (CFU, PLAQUE ASSAY), induction of cell death (FACS), analysis of genes involved in the recognition of bacterial and inflammatory response (RT-PCR, RPA), production of pro-inflammatory cytokines and chemokines (ELISA) and nitric oxide (NO) (GRIESS). In this work was possible to observe that: (i) the ability to spread and (ii) the induction of cell death in Caco-2 cells was significantly higher in S. flexneri infection than EIEC, (iii) there are differences regarding the relative expression of genes of Caco-2 cells involved in the recognition of two bacterial strains. It was highlighted the essential role of intracellular receptors in recognition of bacterial by Caco-2 cells, and the expression of mRNA of the intracellular receptor Nod 1 was higher for EIEC when compared with S. flexneri, (iv) there are significant differences in the kinetics of NO production by Caco-2 infected cells, EIEC induced a early NO production when compared with S. flexneri. These data indicate that the intestinal epithelial cells recognize and respond in a different way to these bacterial species and induce an inflammatory response more efficient in control of the infection induced by EIEC.

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