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1
Brittain, George C. IV. "A Novel Role for the TRAFs as Co-Activators and Co-Repressors of Transcriptional Activity." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/451.
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The tumor necrosis factor (TNF) receptor-associated factors (TRAFs) were initially discovered as proteins that inducibly interact with the intracellular region of TNF receptors (TNFRs). Because the TNFRs lack intrinsic catalytic activity, the TRAFs are hypothesized to orchestrate signaling activation downstream of the TNFR superfamily, however their mechanism of activation remains unclear (Inoue et al., 2000; Bishop, 2004). Originally, the TRAFs were compared to the signal transducers and activators of transcription (STAT) protein family, due to their sequence homology, and the presence of multiple RING- and zinc-finger domains, suggesting that their function may be to regulate transcriptional activity (Rothe et al., 1994; Hu et al., 1994; Sato et al. 1995; Cheng et al., 1995). However, subsequent research focused predominantly on their cytoplasmic functions, and more recently on their function as E3 ubiquitin ligases (Pineda et al., 2007). In my research, I analyzed the subcellular localizations of the TRAFs following CD40 ligand (CD40L)-stimulation, and found that TRAF2 and 3 rapidly translocate into the nucleus of primary neurons and Neuro2a cells. Interestingly, similar analysis conducted in pre-B lymphocytes (Daudi cells) revealed a different response to CD40L-stimulation, with TRAF2 and 3 being rapidly degraded within 5-minutes of stimulation. These findings are significant because they demonstrate for the first time that the TRAFs translocate into the nucleus and suggest that they may function within the nucleus in a cell-specific manner. I next analyzed the ability of TRAF2 and 3 to bind to DNA, and found that they both bind to chromatin and the NF-kappaB consensus element in Neuro2a cells, following CD40L-stimulation. Similar analyses of the chromatin binding of TRAF2 and 3 in Daudi cells revealed that they were rapidly degraded, similar to the results from my analysis of their subcellular localization. These findings show for the first time that the TRAFs interact with DNA, and therefore support the hypothesis that the TRAFs may function within the nucleus as transcriptional regulators. Finally, I analyzed the ability of the TRAFs to regulate transcriptional activity by luciferase assay. Previous studies showed that overexpression of TRAF2 and 6 could induce NF-kappaB transcriptional activity; however researchers have not been able to determine the mechanism by which they do so. In my studies, I found that every TRAF can directly regulate transcriptional activity either as co-activators or co-repressors of transcription, in a cell- and target protein-specific manner. Additionally, I found that TRAF2 can act as a transcriptional activator, and that its ability to regulate transcription is largely dependent upon the presence of its RING-finger domain. In conclusion, these studies have revealed an entirely novel function for the TRAFs as immediate-early transcriptional regulators. Future research into the genes that are regulated by the specific TRAF complexes will further elucidate how the TRAFs regulate TNFR signaling, as well as whether dysfunctions in TRAF signaling may be associated with known disorders. If specific TRAF complexes are found to regulate specific genes, then pharmacological targeting of the individual TRAF complexes may allow for the highly specific inhibition of signaling events downstream of the TNFRs, without compromising overall receptor signaling, transcription factor pathways, or cellular systems.
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Gardam, Sandra Clinical School St Vincent's Hospital Faculty of Medicine UNSW. "Regulation of lymphocyte development and function by TRAF2 and TRAF3." Publisher:University of New South Wales. Clinical School - St Vincent's Hospital, 2008. http://handle.unsw.edu.au/1959.4/42104.
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Tumour necrosis factor receptor (TNFR) family members are widely expressed in cells of the immune system and are essential for the development and function of many immune cell types. The TNFR associated factor (TRAF) family are signal adapter molecules that are recruited to various members of the TNFR family and are important for the transduction of signals downstream of these receptors. In these studies, gene targeting was used to create a mouse capable of undergoing conditional inactivation of the Traf3 gene. These mice were studied alongside previously generated mice that were similarly genetically modified with respect to the Traf2 gene. The mice produced lacked expression of either TRAF2 or TRAF3 in either B or T cells. In resting B cells TRAF2 and TRAF3 were shown to cooperate to negatively regulate the signalling of B cell activating factor of the TNF family (BAFF) and its receptor (BAFF-R), the TNF ligand and receptor pair that provide obligate survival signals to B cells. Thus, TRAF2- and TRAF3-deficient B cells displayed hyperactive NF-kB2 signalling, an increased ability to survive, and almost identical gene expression profiles, emphasizing the cooperative nature of their roles in resting B cells. Importantly, the survival of these B cells was completely independent of BAFF. In normal B cells, BAFF signalling was shown to lift the negative regulation of survival mediated by TRAF2 and TRAF3, by depleting TRAF3 from the cell. This process was shown to require TRAF2. T cells deficient in TRAF2 or TRAF3 also displayed hyperactivity of the NF-kB2 pathway, but they did not accumulate in vivo or show extended survival in vitro. Mice lacking TRAF2 or TRAF3 in their T cells did however display a decrease in the number of memory phenotype CD8+ T cells. These studies indicate that some of the roles of TRAF2 and TRAF3 are common between B and T cells. However, the consequences of loss of TRAF2 or TRAF3 in B and T cells differs considerably, presumably due to the differential TNFR expression and usage by each cell type.
3
Graham, John. "CD40-Induced TRAF degradation in immune regulation." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/808.
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CD40 is a TNF receptor superfamily (TNFRSF) member central to the development of many aspects of the adaptive immune response. CD40 signaling promotes adaptive immunity in part by inducing the expression of cytokines, chemokines, and various adhesion and co-stimulatory molecules. The family of cytoplasmic adapter proteins, the TNFR-associated factors (TRAFs), serve as major mediators of TNFRSF pathways. CD40 regulates itself in part via the signaling induced degradation of TRAF2 and TRAF3. However, the effect of CD40-induced TRAF degradation on other TRAF dependent pathways is unknown. Here I provide evidence that CD40-mediated degradation of TRAFs 2 and 3 also influences the responsiveness of immune cells to CD40-independent, TRAF2- and 3-dependent pathways.
LMP1 is a functional mimic of CD40, but signals to B lymphocytes in an amplified and sustained manner. LMP1 contributes to the development of B cell lymphoma in immunosuppressed patients, and may exacerbate flares of certain autoimmune diseases. The cytoplasmic (CY) domain of LMP1 binds TRAF2 with lower avidity than the CY domain of CD40, and TRAF2 is needed for CD40-mediated degradation of TRAFs 2 and 3. LMP1 doesn't induce TRAF degradation, and employs TRAF3 as a positive mediator of cell signaling, whereas CD40 signals are inhibited by TRAF3. Here, I tested the hypothesis that relative affinity for TRAF2, and/or distinct sequence differences in the TRAF2/3 binding sites of CD40 vs. LMP1, controls the disparate ways in which CD40 and LMP1 use TRAFs 2 and 3. The results revealed that TRAF binding affinity and TRAF binding site sequence dictate a distinct subset of CD40 vs. LMP1 signaling properties.
The E3 ubiquitin ligases, cIAP1 and cIAP2, have been reported to play a crucial role in CD40 signaling. Because LMP1 is a mimic of CD40 signals, I hypothesized that LMP1 requires the cIAPs for signaling. To elucidate the role of the cIAPs in CD40 and LMP1 signaling, I specifically depleted the cIAPs and found that the cIAPs are differentially utilized in CD40 and LMP1 signaling. I also sought to further the understanding of the molecular underpinnings of how CD40, but not LMP1 signaling induces TRAF2 and TRAF3 degradation upon signaling. To do this, I investigated the ability of various CD40 and LMP1 mutants to induce TRAF degradation in distinct TRAF or cIAP deficient models. I found that neither a high TRAF2 binding potential nor the presence of the cIAP molecules are required for this process. Thus, this work reveals important insights into the molecular mechanisms of and role of CD40-mediated TRAF degradation in the immune system.
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Hauer, Julia. "Signaltransduktion durch TRAF-bindende Mitglieder der TNF-Rezeptor-Superfamilie (TNFR-SF)." Diss., lmu, 2006. http://nbn-resolving.de/urn:nbn:de:bvb:19-57662.
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Anto, Michel Nathaly [Verfasser], Andreas [Akademischer Betreuer] Zirlik, and Rudolf [Akademischer Betreuer] Grosschedl. "The role of tumor necrosis associated factor (TRAF)-1 in cardio-metabolic disease." Freiburg : Universität, 2017. http://d-nb.info/1173086897/34.
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Foight, Glenna Wink. "Determinants of protein-peptide interaction specificity in the Bcl-2 and TRAF families." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101350.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, September 2015.Cataloged from PDF version of thesis. "September 2015."
Includes bibliographical references.
Protein-peptide interactions have important roles in the majority of cellular processes. There are many families of peptide recognition domains in which homologous members display differential binding preferences for peptide sequence features. Peptide binding specificity is critical for the functional roles played by each family member, which can be overlapping or distinct. The two peptide recognition domain families discussed in this work, Bcl-2 and TRAF proteins, have roles in cellular processes including apoptosis, inflammation, and immunity. Aberrant function of these proteins has been linked to a variety of diseases. There is great interest in understanding the mechanistic basis of protein-peptide binding specificity in these families and others. An improved understanding will enable models of binding preferences for interactome prediction and design of specific peptide reagents for the inhibition and study of protein-peptide interactions. The anti-apoptotic Bcl-2 family members bind [alpha]-helical Bcl-2-homology 3 (BH3) motifs in pro-apoptotic Bcl-2 family members to prevent apoptosis. Kaposi Sarcoma herpesvirus and Epstein Barr herpesvirus express viral homologs of the anti-apoptotic Bcl-2 proteins, KSBcl-2 and BHRF 1, respectively, during viral replication to prevent host cell death. Because human Bel- 2 proteins are important in preventing apoptosis in cancers, there is interest in targeting the viral homologs, as they may also have a role in herpesvirus-associated malignancies. I designed and screened libraries of BH3 peptide variants for binding specificity to KSBcl-2 and BHRF 1. From library screening and additional rational mutagenesis, I developed peptides that showed specific binding to KSBcl-2, BHRF 1, or the human homolog Ml- 1, and displayed large margins of specificity over the other human Bel-2 homologs. TRAF proteins bind sequences in the unstructured regions of cell surface receptors and other adapter proteins in order to mediate downstream signaling events. TRAF-peptide binding preferences are relatively uncharacterized. I adapted a bacterial surface display system for screening peptides for TRAF binding. Using this system, I explored the binding preferences of TRAFs 2, 3, and 5 to single and double mutant libraries of two peptide interaction partners from CD40 and TANK. Comparison of the enriched peptide sequences reveals a surprising degree of difference between these three close TRAF homologs, yielding hypotheses relevant to TRAF function and inhibition.
by Glenna Wink Foight.
Ph. D.
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Bani, Younes Maram Younis Saleh. "Efficient Traffic Control Protocols for Vehicular Ad-Hoc Networks." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32060.
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Traffic efficiency applications over road networks have been investigated recently using VANETs. This area of research is primarily concerned with increasing the traffic fluency over road networks. In this thesis, we first propose an efficient and accurate protocol to detect congested road segments in a downtown area using VANETs. We refer to this protocol as the Efficient COngestion DEtection (ECODE) protocol. ECODE evaluates three different traffic characteristics of each road segment including traffic speed, traffic density, and the time required to travel the segment. Moreover, ECODE evaluates traffic characteristics and detects the congestion level in each direction of the road segment. In addition, we propose an intelligent, dynamic, distributed, and real-time path recommendations protocol. We refer to this protocol as Intelligent path reCOmenDation (ICOD) protocol. ICOD is the first path recommendation protocol that does not rely on a central database of gathered traffic data for each area of interest. Eliminating centralized behavior resolves bottleneck as well as single point of failure problems, which in turn
minimizes congestion and collision problems in VANETs. Furthermore, ICOD selects the path towards each destination in a hop-by-hop manner, which makes the turn decision at each road intersection more accurate and real-time. Different variants of ICOD are introduced that consider travel time, travel distance, fuel consumption, gas emissions, and context-awareness of each road segment parameters. Moreover, two traffic balancing mechanisms are proposed in this thesis to distribute traffic over the road network evenly, namely Bal-Traf and Abs-Bal. These mechanisms eliminate the highly congested road segment scenarios that are caused by the path recommendation protocol. Bal-Traf detects and eliminates the highly congested output road segment at each road intersection. However, Abs-Bal aims to keep the traffic density balanced among all output road segments at each road intersection. Finally, we propose an Intelligent Traffic Light Controlling (ITLC) algorithm to schedule the phases of each traffic light at isolated road intersections. This algorithm aims to decrease the queuing delay time of competing traffic flows and to increase the throughput of each signalized road intersection. ITLC has also been adapted in this thesis to the Arterial Traffic Lights (ATLs) algorithm for arterial road network scenarios. In ATLs the expected platoons on the arterial street are considered in the scheduling algorithm of each traffic light located on the arterial street coordinates. Transmitting packets among these traffic lights report the main characteristics of each predicted platoon.
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CAZZANIGA, FEDERICO ANGELO. "IL RUOLO DEL PATHWAY SOCS-1/TRAF-6 NELL'INCREMENTO DELL'OSTEOCLASTOGENESI IN PAZIENTI HIV+ IN CART." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/548313.
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Up to 30% of cART treated HIV-infected patients show an early onset osteopenia/osteoporosis, leading to a significant increase in the risk of fractures. The pathogenic molecular mechanisms remain poorly understood. However, it has been shown that, in HIV transgenic rats model, osteoclasts (OCs) express high levels of suppressor of cytokine signaling-1 (SOCS-1) and tumor necrosis factor receptor-associated factor-6 (TRAF-6), inducing an increased osteoclastogenesis through IFN-γ pathway inhibition. Given these premises, our study aims to investigate osteoclastogenesis and SOCS-1/TRAF-6 pathways in human peripheral blood-derived-OCs of HIV positive cART-treated patients with and without reduced BMD (Bone Mineral Density).
Material and Methods.
We consecutively enrolled 40 HIV+ patients on virally-effective cART (HIV-RNA <40cp/ml) matched for viro-immunologic/demographic features: 16 resulted with normal BMD (nBMD) by dual x-ray absorptiometry (osteopenia, z-score -1/-2.5; osteoporosis, z-score <-2.5), 24 with reduced BMD (rBMD, including osteopenic and osteoporotic patients). We enrolled 15 HIV-negative as healthy controls (HIV-). Circulating OC precursors (OCPs; CD14+CD11b+CD51/61+ and C14+/CD16++) were studied by flow-cytometry. OCs were differentiated from peripheral blood-purified CD14+ supplemented with M-CFS and RANKL (8 days). OCs differentiation/maturation was evaluated by: TRAP staining and dentin resorption. RANK, SOCS-1, TRAF6, MMP-9 and CTSK expression of OCs ex vivo differentiated were analyzed by Real-Time PCR and Western-Blot with and without IFN-γ stimulation (100 U, 2 h). Kruskal-Wallis, Mann–Whitney and ANCOVA were used.
Results.
Higher levels of OCPs (CD14+CD11b+CD51/61+ and C14+/CD16++) were observed in HIV+ rBMD group compared to HIV+ nBMD (respectively, p=.0001; p=.0068). CD14+ cultures from HIV+ rBMD were enriched in large multinucleated TRAP+ OCs versus nBMD and HIV- (p=.012; p=.023), as confirmed by TRAP quantification (p=.038; p=.04). Interestingly, OCs from HIV+ rBMD expressed significantly higher SOCS-1 and TRAF-6: > 2.14, >1.65 fold vs HIV-, respectively, significantly higher than nBMD (p=.027; p=.014). IFN-γ challenge resulted in an up-regulation of SOCS-1 in HIV+ rBMD/nBMD OCs and HIV- OCs, respectively (p=.0022; p=.0057; p=.0013). Despite this, only in HIV+ rBMD we detected an increasing in TRAF-6 (p=.024). No difference was found in MMP-9, on the contrary we observed an increasing trend of CTSK mRNA expression in HIV+ rBMD OCs. Interestingly, ANCOVA test demonstrated an interaction between SOCS-1/ TRAF-6 upregulation, HIV infection and bone impairment (p=.003, p=.025).
Conclusion.
HIV+ rBMD patients show increased circulating OCPs and OCs ex-vivo differentiation, indicating heightened osteoclastogenesis in treated HIV+ osteopenic/osteoporotic patients. Relevantly, we show that OCs from HIV+ rBMD express high SOCS-1/TRAF-6 levels, that are further upregulated upon IFN-γ challenge. Together, these findings identify deregulated SOCS-1/TRAF-6 as molecular pro-osteoclastogenesis pathway that might be sustained by abnormal interferon-mediated inflammation in successfully-treated HIV.
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Cartier, Jessy. "Influence de clAP1 sur la prolifération cellulaire." Thesis, Dijon, 2010. http://www.theses.fr/2010DIJOS016.
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La protéine cIAP1 (cellular Inhibitor of Apoptosis Protein-1) de la famille des IAP (Inhibitor of Apoptosis Protein) est une E3 ubiquitine ligase qui présente des propriétés oncogéniques. Notre équipe s’intéresse aux processus permettant la différenciation des monocytes en macrophages. Au cours de la différenciation de nombreux modèles cellulaires (macrophages, cellules dendritiques, cellules épithéliales du colon, cellules souches hématopoïetiques, cardiomyocytes), cIAP1 sort du noyau pour se relocaliser dans le cytoplasme. La plupart des fonctions connues de cIAP1 sont liées à sa localisation cytoplasmique où elle est un régulateur important des voies de signalisation des récepteurs du TNFα et de NF-κB. Lors de la différenciation macrophagique, nous avons montré que cIAP1, une fois dans le cytoplasme, induit la dégradation de TRAF-2, un adaptateur moléculaire impliqué dans la transduction du signal des voies des récepteurs du TNFα et de NF-κB. Cette dégradation bloque la voie canonique de NF-κB et est essentielle à la différenciation terminale des monocytes en macrophages qui nécessite une activation transitoire de cette voie de signalisation. Cependant, cIAP1 est principalement exprimée dans le noyau de différents types cellulaires ce qui n’est pas en accord avec son rôle dans la signalisation cellulaire. Mon objectif a donc consisté à identifier les fonctions nucléaires de cIAP1 dans des cellules prolifératives ou lors de la différenciation macrophagique. Mon travail de thèse a permis d’identifier un rôle de cIAP1 dans la prolifération cellulaire. cIAP1 interagit avec le facteur de transcription E2F1 et favorise son recrutement sur les promoteurs des Cycline E et A impliquées dans les transitions G1/S et G2 du cycle cellulaire, ce qui augmente l’expression des transcrits et des protéines de ces deux cibles. Il semblerait que par cette activité, cIAP1 régule la prolifération des cellules et soit important dans l’équilibre entre la prolifération et la différenciation, deux mécanismes cellulaires étroitement liésThe inhibitor of apoptosis protein cIAP1 (cellular inhibitor of apoptosis protein-1) from the IAP family (Inhibitor of Apoptosis Protein) is an E3 ubiquitin ligase that displays oncogenic properties. Our team is interested in the mecanisms that allow macrophagic differentiation from monocytes. cIAP1 is relocalised from the nucleus to the cytoplasm during the differentiation of many kind of cellular models (macrophages, dendritic cells, colon epithelial cells, hematopoietic stem cells, cardiomyocytes). The well-known functions of cIAP1 are associated with its cytoplasmic localisation, where it regulates the TNFα receptors and NF-κB signalling pathways. During macrophage differentiation, we show that cIAP1, once it is in cytoplasm, induces TRAF-2 degradation, a molecular adaptator of the TNFα receptors family and NF-κB signalling pathways. This degradation blocks the canonical pathway of NF-κB and is essential for the terminal differentiation into macrophages that needs a transitory activation of this pathway. However, cIAP1 is mainly expressed in the nucleus on many cell types which is not in accordance with its cell signalling activity. My objective was to investigate the nuclear function of cIAP1 in proliferative cells or during macrophage differentiation. My work identifies a function of cIAP1 in proliferation regulation. cIAP1 interacts with E2F1 transcription factor and favors its recruitment on Cyclins E and A promoters, both involved in G1/S and G2 phases of the cell cycle, which leads to high level of transcript and protein expression of these two targets. It seems that cIAP1 regulates the cellular proliferation and is important for the balance between proliferation and differentiation, two mechanisms tightly connected in cells
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Silva, Rodrigo Borsatto Sommer da. "Projeto destinos indutores: avanços e desafios do TRAF - Turismo Rural na Agricultura Familiar em Rancho Queimado (SC)." Universidade do Estado de Santa Catarina, 2010. http://tede.udesc.br/handle/handle/1408.
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Previous issue date: 2010-04-08Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O Projeto Destinos Indutores é uma proposta do MTur - Ministério do Turismo para estruturar 65 destinos indutores com qualidade turística internacional. Deste projeto reservou-se 10 destinos para atender a estruturação de segmentos turísticos. Entre esses está o TRAF - Turismo Rural na Agricultura Familiar que deve ser organizado e estruturado por quatro municípios de Santa Catarina, entre eles Rancho Queimado. O TRAF é um segmento turístico realizado no espaço rural, que busca por meio da aproximação entre turistas e agricultores familiares, a valorização do patrimônio cultural e do meio ambiente local. Certamente a organização, planejamento e a presença do GTTuR Grupo Técnico de Turismo Rural e da Associação de Agroturismo Acolhida na Colônia foram fatores determinantes na escolha de Santa Catarina como referência do TRAF no Brasil. O diálogo sobre esse segmento está voltado a entender como o TRAF pode ser utilizado como ferramenta de estímulo a participação popular no planejamento e organização do turismo municipal. Para isso, se utilizou as ideias de desenvolvimento socioespacial e autonomia para auxiliar a compreensão das dinâmicas sociais ocorridas no município de Rancho Queimado. Por conta disso, essa pesquisa busca analisar a contribuição do Projeto Destinos Indutores para a participação comunitária no planejamento e organização do turismo rural na agricultura familiar de Rancho Queimado (SC). Através desses objetivos pretende-se entender: como o Projeto Destinos Indutores pode incentivar a participação comunitária na organização do turismo rural na agricultura familiar em Rancho Queimado? Essa pesquisa caracteriza-se quanto à abordagem do problema como qualitativa e de cunho exploratório. O método de procedimento é o estudo de caso
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Giehler, Fabian. "Etablierung der Interaktion des viralen Onkoproteins LMP1 mit den zellulären Signalproteinen der TRAF-Proteinfamilie als Zielstruktur für Inhibitoren." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-158962.
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Das Epstein-Barr Virus (EBV) ist mit einer Reihe von lebensbedrohlichen Krankheiten assoziiert. Dazu zählen unter anderem Nasopharynxkarzinome, Hodgkin-Lymphome und lymphoproliferative Erkrankungen nach Organtransplantationen. Dennoch gibt es bisher keinen wirksamen Therapieansatz, der sich spezifisch mit der Rolle von EBV in diesen malignen Erkrankungen auseinandersetzt.
Das latente Membranprotein 1 (LMP1) ist das primäre Onkogen von EBV und essenziell für die Transformation von B-Zellen durch das Virus. Für eine effiziente Transformation von Zellen ist die Aktivierung verschiedener zellulärer Signalwege durch LMP1 notwendig. LMP1 besitzt jedoch keine enzymatische Aktivität und die Induktion der Signalwege ist somit abhängig von der Rekrutierung verschiedener zellulärer Adapterproteine. Die Ausbildung der notwendigen Signalkomplexe wird über zwei C-terminale Aktivierungs-Regionen (CTAR1 und CTAR2) vermittelt. Verschiedene Mitglieder der Tumornekrosefaktor (TNF)-Rezeptor-assoziierten Faktoren (TRAF)-Protein-Familie spielen bei der Induktion der Signalwege durch diese beiden CTAR-Domänen eine zentrale Rolle.
Nach grundlegenden Protein-Protein-Interaktionsstudien zwischen LMP1 und rekombinanten TRAF-Proteinen wurde hier die Interaktion zwischen TRAF2 und LMP1 als Zielstruktur für Inhibitoren vorgestellt. TRAF2 ist essenziell für die Aktivierung des NF-κB-Signalweges durch die CTAR1-Domäne und somit für das Überleben EBV-transformierter Zellen. Die Bindung von TRAF2 an LMP1 wurde biochemisch näher charakterisiert und die gewonnen Erkenntnisse verwendet, um ein System zu etablieren, mit dem Inhibitoren gegen den Komplex aus LMP1 und TRAF2 identifiziert werden können. Dieses ELISA-basierte System erfüllt die Anforderungen, die allgemein an hochdurchsatzfähige Systeme gestellt werden. In einem Pilotscreen einer Bibliothek mit Naturstoffen wurden Substanzen identifiziert, die die Bindung von TRAF2 an LMP1 in vitro inhibierten. Die potenteste Substanz inhibierte die Interaktion von TRAF2 und LMP1 mit einem IC50 von 8 µM in diesen in vitro Studien. Weiterhin zeigte diese Substanz eine spezifische biologische Wirkung auf die Vitalität von EBV-transformierten B-Zellen.
Zusätzlich konnte in den Protein-Protein-Interaktionsstudien zwischen den verschiedenen TRAF-Proteinen und LMP1 erstmals eine direkte Bindung von TRAF6 an LMP1 gezeigt werden. Entgegen der bisherigen Modellvorstellung, nach der TRAF6 indirekt über Adapterproteine an LMP1 gebunden wird, konnte hier gezeigt werden, dass TRAF6 direkt an die LMP1-Sequenz P379VQLSY innerhalb der CTAR2-Domäne bindet. Diese Sequenz ist essenziell für die Aktivierung verschiedener TRAF6-abhängiger Signalwege durch die CTAR2-Domäne. Auf der Oberfläche von TRAF6 wird die Bindung an LMP1 durch dieselbe Bindetasche vermittelt, über die auch die Interaktion mit zellulären Rezeptoren stattfindet. Diese direkte Interaktion zwischen LMP1 und TRAF6 ist wichtig für die Aktivierung des NF κB-Signalweges durch die CTAR2-Domäne. TRAF6-Mutanten, die nicht mehr in der Lage waren, mit LMP1 zu interagieren, waren ebenfalls nicht mehr dazu fähig, die Induktion von NF κB-Signalen durch die CTAR2-Domäne von LMP1 in embryonalen TRAF6-/- Mausfibroblasten wiederherzustellen.
Ebenfalls konnte neben der direkten Bindung von TRAF6 an LMP1 hier eine weitere neue Protein-Protein-Interaktion für TRAF6 beschrieben werden. TRAF6 bindet direkt an das TNF-Rezeptor-assoziierte Todesdomänenprotein (TRADD). Die Interaktion zwischen TRAF6 und TRADD unterscheidet sich jedoch von der Bindung anderer TRAF-Proteine an TRADD. Die in vitro Studien zeigten, dass TRAF6 in der Lage ist, sowohl mit Teilen des N-Terminus, als auch mit Teilen des C-Terminus von TRADD zu interagieren. Diese bisher nicht beschriebene Art der direkten Interaktion von TRAF6 mit TRADD eröffnet neue Einblicke in den Aufbau des LMP1-Signalkomplexes.
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Petsche, Matthias. "Der Tag, an dem ich meinen toten Mann traf die Filmmusik und ihr Umgang mit einem unerträglichen Verlust." [Potsdam] [Hochsch.-Bibliothek], 2009. http://d-nb.info/995614083/34.
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Rudolf, Philipp Michael [Verfasser], and Andreas [Akademischer Betreuer] Zirlik. "TRAF 5 Defizienz beschleunigt die Ausbildung von Atherosklerose in Mäusen durch vermehrte Rekrutierung inflammatorischer Zellen und verstärkte Schaumzellbildung." Freiburg : Universität, 2012. http://d-nb.info/1123465851/34.
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Arcipowski, Kelly Marie. "Molecular mechanisms of TRAF6 function in signaling pathways of the oncogenic viral mimic of CD40, LMP1." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/3560.
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Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) plays important roles in EBV-mediated B cell transformation, development of EBV-associated malignancies, and exacerbation of certain autoimmune conditions. LMP1 functionally mimics tumor necrosis factor receptor (TNFR) superfamily member CD40, but LMP1 signals are amplified and sustained compared to those induced by CD40. CD40 and LMP1 rely on TNFR-associated factors (TRAFs) to mediate signaling, but use TRAFs differently. TRAF6 is important for CD40 signaling, and was implicated in LMP1 signaling in non-B cells. Here, we addressed the hypothesis that TRAF6 is a critical regulator of a subset of LMP1 signals in B cells.
We found that TRAF6 was required for LMP1-mediated kinase activation and costimulatory molecule upregulation, and associated with the LMP1 TRAF1/2/3/5 binding site (TBS). Additionally, TRAF6 and the TBS contributed to LMP1-induced autoreactivity and antibody (Ab) production in vivo. Finally, in contrast to CD40, LMP1 required the TRAF6 receptor-binding domain to mediate TRAF6-dependent pathways. Thus, TRAF6 is critical for LMP1 signaling and requires LMP1 interaction to propagate signals. Importantly, TRAF6 associates with LMP1 in a manner distinct from CD40, raising the possibility of disrupting LMP1 functions while leaving normal CD40 signaling intact. We next investigated roles of the kinase TAK1 in TRAF6-dependent LMP1 functions. TAK1 was required for CD40- and LMP1-mediated JNK activation in B cells, leading to IL-6 and Ab production.
Understanding mechanisms of CD40 and LMP1 signaling provides important insights into normal regulatory control of CD40 functions and how LMP1-mediated pathogenesis escapes or subverts these regulatory mechanisms. LMP1 itself may be a difficult therapeutic target, because it lacks an extracellular domain and is continually processed from the cell surface. Thus, it is important to elucidate similarities and differences between CD40 and LMP1 signals to identify therapeutic targets to block LMP1-mediated pathogenesis. Comparing and contrasting CD40 and LMP1 also increases our understanding of the critical mechanisms used to regulate normal CD40 signaling.
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Giehler, Fabian [Verfasser], and Bettina [Akademischer Betreuer] Kempkes. "Etablierung der Interaktion des viralen Onkoproteins LMP1 mit den zellulären Signalproteinen der TRAF-Proteinfamilie als Zielstruktur für Inhibitoren / Fabian Giehler. Betreuer: Bettina Kempkes." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/1042147256/34.
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Hieber, Saskia [Verfasser], Volker [Akademischer Betreuer] Eulenburg, and Christian P. [Gutachter] Müller. "Die Rolle von TRAF family member-associated NF-kappa-B activator (TANK) bei der Entstehung der Alkoholsucht / Saskia Hieber ; Gutachter: Christian P. Müller ; Betreuer: Volker Eulenburg." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2019. http://d-nb.info/119687591X/34.
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Peramuhendige, Pushpabhani Prabha. "Role of TRAF2/6 in tumour growth and bone metastases associated with breast cancer." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25800.
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Tumour necrosis factor receptor associated factors (TRAFs) play a key role in signal transduction in mammalian cells. Several members of the TRAF family have been identified but only TRAF2 and TRAF6 are implicated in the regulation of both osteoclastic bone resorption and breast cancer. Here I studied the role of TRAF2 and TRAF6 in breast cancer induced osteoclastogenesis and osteolysis. I observed that TRAF2, but not TRAF6, is highly expressed in a highly metastatic bone-tropic clone of the human MDA-MB-231-BT (MDA-231-BT) breast cancer cells when compared to parental MDA-MB-231 (MDA-231) cells. Targeted knockdown of TRAF2, but not TRAF6, in both parental MDA-231 and bone-tropic MDA-231-BT breast cancer cells by siRNAs markedly reduced cell migration and significantly reduced the ability of these cells and their conditioned medium to induce osteoclast formation in RANKL stimulated bone marrow cultures. Encouraged by these data, I generated stable parental MDA-231 and bone-tropic MDA-231-BT breast cancer cell lines overexpressing TRAF2 using a retroviral approach. Then, I went on to show that overexpression of TRAF2 in parental MDA-231 cell line significantly stimulated directed cell migration and 3D invasion in vitro. Bone-tropic MDA-231-BT breast cancer cells over expressing TRAF2 or their conditioned medium were significantly effective in enhancing RANKL induced osteoclast formation in vitro. Mechanistic studies in parental MDA-231 and bone-tropic MDA-231-BT breast cancer cells revealed that over-expression of TRAF2 enhanced cell migration and osteoclastogenesis via a mechanism that involves the activation of the breast cancer oncogene IKKepsilon (IKKε) coupled with significant increase in levels of Vascular endothelial growth factor (VEGF). Ex vivo studies in human MDA-231-mouse calvaria organ co-cultures showed that conditioned medium obtained from MDA- 231 cells enhanced calvarial osteolysis. In vivo studies showed that overexpression of TRAF2 in the human breast cancer cells MDA-231 enhanced tumour incidence and tumour volume after orthotopic injection and exacerbated osteolysis after supracalvarial injection of conditioned medium from these cells. In conclusion, our studies showed that the TRAF2/IKK/VEGF axis in breast cancer cells regulates breast cancer cell motility in vitro, osteoclastogenesis in vitro and osteolysis ex vivo and in vivo. However, the role of TRAF2 in bone metastasis associated with breast cancer will require further in vivo investigation.
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Плотиця, Володимир Мирославович, and Volodymyr Plotytsia. "Дослідження умов безпеки руху на маршруті Тернопіль – Вінниця та розробка заходів організації дорожнього руху." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2020. http://elartu.tntu.edu.ua/handle/lib/33939.
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Роботу виконано на кафедрі автомобілів Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться 23 грудня 2020 р. о 10:00 годині на засіданні екзаменаційної комісії № 20 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Текстильна, 28, навчальний корпус № 9.У дипломній роботі магістра представлено план організації ефективного і безпечного дорожнього руху на нерегульованому перехресті траси М12 (162- 163 км) та вул. Головна. Мета проекту - дослідження та аналіз параметрів дорожнього руху, визначення шляхів по покращенню показників транспортних потоків на досліджуваному перехресті.
ВСТУП...7 1 ТЕОРЕТИЧНИЙ РОЗДІЛ...8 1.1 Дослідження дорожнього руху на перехресті траси М12(162-163 км).. 8 1.1.1 Розміщення, способи встановлення та характеристика дорожніх знаків...11 1.1.2 Розміщення, методи нанесення та характеристика дорожньої розмітки...14 1.2 Огляд діяльності підприємства...16 1.3 Постановка завдання для кваліфікаційної роботи магістра...17 1.4 Висновки до Розділу 1 ...18 2 АНАЛІТИКО-ДОСЛІДНИЦЬКИЙ РОЗДІЛ...19 2.1 Натурні дослідження швидкостей на перехрестях...19 2.1.1 Визначення складу та інтенсивності транспортних потоків...22 2.1.2 Визначення швидкості транспортних потоків...23 2.2 Конфліктологія на вулично-дорожній мережі...28 2.2.1 Розрахунок небезпеки перехрещення за п’ятибальною системою оцінювання конфліктних точок...30 2.3 Визначення нерівномірності руху транспортного потоку...32 2.4 Висновки до Розділу 2 ...36 3 ПРОЕКТНО-РЕКОМЕНДАЦІЙНИЙ РОЗДІЛ...37 3.1 Аналіз даних за результатами дослідження на перехресті траси М12 (162-163 км) та вул. Головна...37 3.2 Обґрунтування актуальності дослідження задачі підвищення ефективності функціонування вулично-дорожньої мережі...42 3.3 Умови та технічні засоби організації дорожнього руху...45 3.4 Мікромоделювання ділянки ВДМ на перехресті М12 (162 – 163 км) та вул. Головна...493.5 Економічна ефективність прийнятих рішень...51 3.6 Висновки до Розділу 3 58 4 ОХОРОНА ПРАЦІ ТА НЕБЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ...59 4.1 Охорона праці при будівництві, ремонті та утриманні автомобільних доріг...59 4.1.1 Будівництво покриттів автомобільних доріг...60 4.1.2 Ремонт і утримання автомобільних доріг...61 4.2 Охорона праці при роботі окремих дорожніх машин...64 4.3 Охорона довкілля при експлуатаційному утриманні автомобільних доріг...65 4.4 Висновки до Розділу 4 66 Висновки...67 Список використаних джерел...68
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Schinagl, Rosa Kassandra Coco. ""Dieser Satz traf mich mitten ins Hers, also darf ich ihn doch haben" : Liebe als philosophisch-theologisches Konzept in Hannah Arendts Denken. Eine Betrachtung ihrer Dissertation Der Liebesbegriff bei Augustin. Versuch einer philosphischen Interpretation im Lichte ihres Gesamtwerkes." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71742.
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Seidlová, Vendula. "Studie prodloužení tramvajové tratě do městské části Brno-Medlánky." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371975.
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The aim of the diploma thesis is to design the extension of tram line no. 12 from the current terminal station Technologicky park to the city district Brno-Medlanky. The tram track is situated on the separate road bed outside the built up urban area. Directional and elevational solution of the track is designed in several variants, after the evaluation the best variant is selected and elaborated. The diploma thesis contains the design of the tram stop and the terminal station with baloon loop, including access paths. Adjustment of the crossed road and the drainage system solution is part of the thesis as well.
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Vignac, Benoît. "Reformulation et décomposition pour un problème d'allocation de ressources dans un réseau optique." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2009BOR13996/document.
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Les réseaux optiques sont aujourd’hui l’élément de base des systèmes de communica- tions modernes, en particulier l’Internet. Grâce au multiplexage en longueurs d’onde et au groupage du tra?c, la bande passante disponible sur une ?bre optique est supérieure à plusieurs térabits par seconde. Cependant les équipements opto-électroniques qui permettent d’opérer ces réseaux sont très coûteux car il doivent fonctionner à un débit très important. Le problème de groupage et du routage d’un ensemble de requêtes couplé avec l’affectation des longueurs d’onde (GRWA) est donc un problème stratégique de première importance. L’objectif est de minimiser le coût du réseau, évalué comme le nombre de ports optiques installés aux nœuds. Il peut être modélisé sous la forme d’un problème d’allocation de ressources dans un réseau à capacité multi-niveaux avec multi-?ots non bifurqués. Cette catégorie de problème est connue pour être très dif?cile compte tenu de la faiblesse de la relaxation linéaire des formulations associées. Les travaux réalisés durant cette thèse ont consisté en le développement de méthodes de résolution pour ce problème à partir de multiples techniques de recherche opéra- tionnelle : méta-heuristique de type recherche avec tabous, décomposition de Dantzig- Wolfe, décomposition de Benders, reformulation en variables binaires, méthode de plans coupants, heuristique d’arrondi. Les méthodes résultantes, dont certaines sont hybrides, permettent d’avoir un aperçu des méthodes ef?caces pour ce type de problème. En partic- ulier, les méthodes basées sur la décomposition de Benders, qui donnent lieu à des procédures d’optimisation hiérarchique dans lesquelles l’affectation de longueurs d’onde est placée au dernier niveau, sont les méthodes les plus ef?caces car elles permettent de séparer le routage optique du routage physique. En?n, nous utilisons la meilleure méthode de résolution pour observer l’impact des contraintes de délais sur la qualité des solutionsOptical networks are the core element of modern communication systems and in particu- lar Internet. With wavelength multiplexing and grooming capability, terabits per second bandwidth can be reached. However, opto-electronic equipment used to operate these networks are very expensive as their bit rate must be very large. The grooming, routing and wavelength assignment (GRWA) problem, which consists in minimizing the net- work cost, evaluated by the number of required optical ports, while guaranteeing that each request is granted, is of great interest. The GRWA problem can be modeled as a multi-layer capacitated network design problem with non-bifurcated multi-?ows. This type of problem is known to be hard to solve as their linear relaxation is weak. The objective of this work was to develop solution methods based on multiple oper- ations research techniques : Tabu search based meta-heuristic, Dantzig-Wolfe decompo- sition, Benders decomposition, 0 1 reformulation, cutting-planes, rounding heuristic. The resulting solution tools, some of them hybrid, give a perspective on the effective solution approaches for this type of problem. From the experiments, it turns out that the methods based on Benders’ decomposition, which lead to hierarchical optimization procedures, are the most ef?cient as they allow to separate the optical routing from the physical routing with the wavelength assignment decisions taken in the lower stage sub- problem. In addition to the approach comparison, we use the most effective method to evaluate the impact of the delay constraints on the solution quality
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Pěknicová, Daniela. "Studie prodloužení tramvajové trati do městské části Brno-Lesná." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240168.
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This master’s degree thesis is aiming to provide design solution within extension of tram line no.5 in the town of Brno,which nowadays ends by balloon loop at Štefánikova čtvrť stop at Merhautova street in Černá Pole district. Proposed tram line is designed in the limits of local urban roads and ends by newly designed balloon loop at Okružní street in Lesná district. Within the framework of this thesis new tram super structure is designed together with surrounding urban rous and connection to Halasova náměstí.
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Trabucco, Matteo <1994>. "Edipo oltre Sofocle: i frammenti di Euripide e il fr. trag. adesp. TrGF 458." Master's Degree Thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/14498.
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La seguente ricerca propone uno studio sistematico dei frammenti euripidei dell'Edipo, al fine di evidenziare il diverso taglio drammatico dato al mito rispetto alle note rese tragiche sofoclee. I frammenti sono presentati nell'elaborato corredati di apparato critico, traduzione italiana e commento puntuale al testo. Un’appendice verrà inoltre dedicata all’analisi del frammento tragico adespoto TrGF 458.
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Nguyen, Tran Diem Hanh. "Semantic-based topic evaluation and application in information filtering." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/209882/1/Tran%20Diem%20Hanh_Nguyen_Thesis.pdf.
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Topic modelling techniques are used to find the main themes in a collection of documents automatically. This thesis presents effective topic evaluation models to measure the quality of the discovered topics. The proposed techniques use human defined knowledge to solve the problems of evaluating topics in terms of semantic meaning of the topics. The thesis also proposed methods to modelling user interest based on the topic model generated from the user’s documents. The proposed techniques help to measure the quality of the topics and significantly improve the performance of text mining applications.
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Nádvorník, Petr. "Možnosti tramvajového spojení Suchdol - Bohnice." Master's thesis, Vysoká škola ekonomická v Praze, 2017. http://www.nusl.cz/ntk/nusl-359302.
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This diploma thesis deals with the possibilities of building a tram track between the Prague districts of Suchdol and Bohnice. It summarizes basic facts about public transport in general and in Prague, mentions the organization of the Prague Integrated Transport system and its financing. The practical part deals with the specific project of the tram track connecting Suchdol and Bohnice using the already designed tracks Kobylisy - Bohnice and Podbaba - Suchdol. Moreover, the nearby Troja area is added to the project. Based on current bus traffic data, new tram lines serving these areas are suggested. At the final stage, the project is complemented by the new P + R parking lots and the possibilities of their use.
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Tian, Yuan. "Ion Trap Miniaturization Considerations: Space-Charge Effects in Cylindrical Ion Traps and Misalignment Effects in a Two-Plate Linear Ion Trap." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6963.
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Portable mass spectrometers provide convenience for applications where conventional mass spectrometers are not suitable. However, a series of miniaturization issues show up in small mass spectrometers, specifically mass analyzers, that need to be thoroughly addressed before further miniaturization. The work in this dissertation focuses on miniaturization issues of ion trap mass analyzers. Space-charge is one of the major issues in small ion traps affecting their analytical performance. It limits ion trapping capacity when ion-ion repulsion causes spreading of a packet of ions. Simulation studies on the relationship between different trap dimensions and trapping capacity was done on a geometry-optimized cylindrical ion trap. A reasonable way of scaling the two important operating parameters (trapping voltage and trapping frequency as functions of the trap dimension) was discussed and applied in the simulation. The trapping capacity (N) decreased with the physical trap dimension (r0) as expected, and N is scaled exponentially as r0. Scaling laws for trapping parameters are proposed, confirmed by SIMION simulations that evaluate the space charge issue in small ion traps. This effect represents a practical limit in ion trap miniaturization.Geometry deviation is another issue that cannot be neglected in miniaturized ion traps, especially in small linear ion traps (LIT). The LIT our group is working on consists of an assembly of two plates, of which each was made by lithographically patterning a series of electrodes on an insulating plate. It is a promising way of expanding the trap capacity at a small trap dimension. However, misalignment of the two plates might seriously affect its performance, specifically resolution and signal intensity. Simulations were done on the misalignment of two-plate planar LIT in the six possible degrees of freedom (DOF) of misalignment between the two plates. Each DOF's influence on the mass resolution and the ion detection efficiency were discussed. Preliminary data from a previous ceramic plate design was collected while most of the misalignment experiments were done on an improved version. A platform was designed incorporating four motorized stages to precisely control the alignment of the ion trap in vacuum. The new plate design was demonstrated to achieve a better than unit resolution for toluene and deuterated toluene after the plates were aligned. The impact on the resolution and signal intensity from pitch, x-, y- and z-displacement were also experimentally studied.
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Wang, Miao. "Halo Ion Trap Mass Spectrometry: Design, Instrumentation, and Performance." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2458.
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New ion trap mass spectrometry (ITMS) instrumentation, the toroidal IT and halo IT, were developed to meet the significant growth in on-site analysis applications. The miniature toroidal IT mass analyzer was operated with radio frequency (RF) trapping voltages of 3 kVp-p or less. Despite its reduced dimensions, it has roughly the same ion trapping capacity as conventional 3D quadrupole ITs. Unit-mass resolved spectra for n-butylbenzene, xenon, and naphthalene were obtained. The desired linear mass scale was obtained using conventional mass-selective instability scan combined with resonance ejection. The halo IT was also based on toroidal trapping geometry and microfabrication technology, consisting of two parallel ceramic plates, the facing surfaces of which were imprinted with sets of concentric ring electrodes. Unlike conventional ITs, in which hyperbolic metal electrodes establish equipotential boundary conditions, electric fields in the halo IT were established by applying different RF potentials to each ring. The potential on each ring could be independently optimized to provide the best trapping field. The halo IT featured an open structure, allowing easy access for in situ ionization. The toroidal geometry provided a large trapping volume. The photolithographic fabrication method avoided difficulty in meeting the required machining tolerances. Preliminary mass spectra showed resolution (m/δ m) of 60–75 when the trap was operated at 1.9 MHz and 500 Vp-p. Ion ejection through a hole in the center of the trap, and through slits machined in the ceramic plates were evaluated. The latter ejection method was done to mimic the design of the toroidal IT. The preferred electric fields containing higher order components were optimized by adjusting the potentials applied to the electrode rings of the halo IT without changing the original trapping plates and structure of the IT. The performance of the halo IT with 1% to 7% octopole field (A4/A2) components was determined. A best resolution of 280 (m/δ m) was obtained with 5% octopole field. SIMION simulations were used to demonstrate the toroidal trapping of ions and their mass analysis in both toroidal and halo ITs.
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Meng, T. Jr, L. A. Bariola, and T. J. Henneberry. "Comparative Trap Catches in Four Boll Weevil Trap Types." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219782.
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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.Four trap types were used to trap boll weevils at 1 m heights, with and without grandlure, and 2 trap types were compared at 0.5 m height, with and without grandlure. The results indicate trap height may be an important factor in boll weevil catches at certain times during the cotton season. Also trap color, design and other factors may influence trap catches since traps not baited with grandlure caught high numbers of boll weevils during certain times during the cotton growing season.
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Van, Dongen Janelle. "Simultaneous cooling and trapping of 6Li and 85/87Rb." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/351.
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This thesis provides a summary of the laser system constructed in the Quantum Degenerate Gases Laboratory for laser cooling and trapping of 85/87Rband 6Li as well as of experiments that have been pursued in our lab to date. The first chapter provides an overview of the experimental focus of the QDG lab. The second and third chapters provide the fundamental theory behind laser cooling and trapping. The fourth chapter provides details of the laser system. The fifth chapter describes an experiment performed on the subject of dual-injection, performed in collaboration with Dr. James Booth of the British Columbia Institute of Technology (BCIT) involving the dual-injection of a single slave amplifier. The last chapter describes the progress made on the experimental setup needed for the study of Feshbach resonances between 85/87Rb and 6Li and the photoassociative formation of molecules.
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Lomaga, Mark A. "Characterizing the physiologic roles of TRAF6 using TRAF6-deficient mice." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq53829.pdf.
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Peng, Ying. "Novel Ion Trap Made Using Lithographically Patterned Plates." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2776.
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A new approach of making ion trap mass analyzers was developed in which trapping fields are created in the space between two ceramic plates. Based on microfabrication technology, a series of independently-adjustable electrode rings is lithographically patterned on the facing surfaces of each ceramic plate. The trapping field can be modified or fine-tuned simply by changing the RF amplitude applied to each electrode ring. By adjusting the potential function applied to the plates, arbitrary trapping fields can be created using the same set of ceramic plates. Unlike conventional ion traps, the electrodes of planar ion traps have a non-equipotential surface, thus the electric field is independent of electrode geometry and can be optimized electronically. The simple geometry and open structure of planar ion traps address obstacles to miniaturization, such as fabrication tolerances, surface smoothness, electrode alignment, limited access for ionization or ion injection, and small trapping volume, thereby offering a great opportunity for a portable mass spectrometer device. Planar ion traps including the planar quadrupole ion trap and the coaxial ion trap have been designed and tested using this novel method. The planar quadrupole trap has demonstrated a mass range up to 180 Da (Th), with mass resolution typically between 400-700. We have also developed a novel ion trap in which both toroidal and quadrupolar trapping regions are created simultaneously between a set of plates. This "Coaxial Trap" allows trapping and mass analysis of ions in two different regions: ions can be trapped and mass analyzed in either the toroidal or quadrupolar regions, and transferred between these regions. Some simulation work based on the ion motion between two different trapping regions in the coaxial ion trap has been performed. Using a one-dimensional simulation method, ion motion was investigated to transfer ions between these two regions. The effect of the mutipole components in the radial field and axial field, amplitude and frequency of the primary RF and supplementary AC signal were studied to obtain high mass resolution in the axial direction and high transfer efficiency in the radial direction. In all these devices, the independent control of each patterned electrode element allows independent control of higher-order multipole fields. Fields can be optimized and changed electronically instead of physically as is done in conventional traps.
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Fike, William H. "Lobster Sampling Trap." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/FikeWH2007.pdf.
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Smith, Karl. "The Prior Trap." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-09212007-152251/.
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Basic economic theory suggests that the decision to go to college should be based only on the expected costs and benefits of college. The income of the family the student comes from should have no effect. Yet, it does. The two common explanations for this discrepancy, inadequate primary school funding and liquidity constraints are at odds with the facts. I offer a third explanation, economically disadvantaged students attend college at lower rates because they have biased information. This analysis connects to the existing literature in at least three ways. It provides a rational basis for the neighborhood effect., extends work on human capital development indicating that educational paths are set at or before age 16 and helps provide an explanation for the both the increase in the return to education and the slowdown in college graduation growth among young men in the United States.
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Rogers, R. Wesley. "Improvements in Optical Trap Displays." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8686.
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This thesis improves on the design of the Optical Trap Display (OTD), presented in 2018 [1]. Contributions include: real time animation; single beam, multiparticle suspension, point primitive anisotropic scattering, and virtual image approximation. First, real time animation was demonstrated on the OTD for the first time in full color at up to 30Hz refresh. Second, multi-particle systems allow for scaling of the display by a multiplicative factor, potentially up to orders of magnitude greater than the first OTD. Third, anisotropic scattering of point primitives was shown for individual suspended particles and multiple simultaneously suspended particles. Fourth, virtual images have been previously considered impossible in volumetric displays but by using perspective projections we have shown in simulation and experiment for the first time that an effect similar to a virtual image can be created.
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Decker, Trevor Keith. "Planar Linear Ion Traps with Microscale Radii for Portable Mass Spectrometry." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/8814.
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Radio frequency (RF) ion traps based on the quadrupole device developed by Paul and Steinwedel utilize a dynamic electric field to spatially confine the trajectory of charged particles and may be employed as mass spectrometers by selectively ejecting trapped molecules based on the mass to charge ratio. Because of the inherent sensitivity and specificity of this process, ion trap mass spectrometers have become a popular scientific instrument. In the past two decades there has been a push to develop portable ion trap mass spectrometers for in situ mass analysis by geometrically scaling traps to smaller sizes. This decreases the power and vacuum requirements which allows field portable instruments to use smaller/less powerful vacuum pumps and batteries. This dissertation presents the process of miniaturizing the planar linear ion trap (PLIT) to a microscale radius in order to investigate the scaling limits of mass spectrometers. The ultimate end goal is the integration of a PLIT into a portable mass spectrometry system. The PLIT consists of two flat, non-conducting plates, on which fine metal electrodes are patterned using standard microfabrication processes, including photolithography. An RF field is distributed across the electrodes to create a quadrupole electromagnetic potential which traps ions based on their mass to charge ratio. While simple in concept, the PLIT has been developed over a ten-year period including an investigation of a variety of substrate materials and design geometries. This dissertation briefly reviews the optimal fabrication flow and why the stated parameters have advantages over other possible combinations in a coplanar ion trap. Since ion trap miniaturization reduces the trapping volume (which also worsens the SNR and resolution of a mass spectrum), a novel RF phase tracking circuit was developed to exploit a phase locked condition during double resonance ejection. This was implemented on the PLIT to increase SNR before constructing the µPLIT. Better than unit resolutions (0.5 Da, FWHM) and SNR improvements were observed.Lastly, the successful miniaturization of the PLIT to a microscale radius is presented. This was done by redesigning the electrodes on the PLIT surface to have an equivalent trap radius (ro) of 800 μm. The μPLIT successfully confined then resonantly ejected ions with resolutions of approximately 2-3 Da. The performance of the μPLIT was also tested over a range of pressures from 2.5-42×10-3 Torr and retained resolutions between 2.3-2.7 Da. Ultimately, the μPLIT was shown to retain resolutions viable for portable mass spectrometry at pressures in the tens of millitorr while consuming a factor of 3.38 less power than the unscaled PLIT.
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Wang, Jingjing. "Feasibility Study for a Community Scale Conversion of Trap Grease to Biodiesel." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1330024170.
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LaMalfa, Eric M. "Fire - Herbivory Interactions in an East African Savanna: Effects on Acacia Drepanolobium Trees." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7498.
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Globally, changes in plant community structure have occurred in ecosystems where humans have altered natural disturbance regimes. Many plants have adaptive life histories and morphological traits that have coevolved with fire and herbivory, which allows them to thrive despite repeated tissue losses. Therefore, altering the type, frequency, or severity of disturbance affects individual plant growth and competition among species. When these changes benefit or disadvantage different plant functional groups (i.e., grasses, shrubs, trees) it alters ecosystem structure and function. Understanding and predicting these vegetation changes, is critical for conservation and management of biodiversity, wildlife habitat, livestock forage, and water.
Savannas are characterized by the codominance of grasses and trees, but the proportion of tree cover responds dynamically to changes in precipitation, fire, and herbivory. These factors often cause a ‘demographic bottleneck,’ which delays transitions from sapling size (1 m). In this dissertation, I investigated several fire × herbivory interactions to gain a mechanistic understanding of sapling recruitment processes that ultimately affect savanna structure.
I made use of a long-term experiment that used semi-permeable fencing to manipulate presence and absence of different types of herbivores, to explore how fire and different combinations of domestic cattle, meso-wildlife, and megaherbivores (elephant and giraffe) affect sapling recruitment. First, I found clear evidence that a wide range of tree height classes resprout after being top-killed by fire, but they were all subsequently kept short by meso-wildlife browsing. Elephants played a key role in suppressing the largest resprouts after fire possibly because fire had reduced the presence of ant mutualists that defend the trees. Second, I found that in the absence of fire, cattle and wildlife indirectly affected saplings by altering competition with neighboring vegetation. Saplings competed with grass and trees during above-average rainfall years. Bare ground—a condition often caused by overgrazing—was positively associated with sapling growth. The highest sapling growth, however, occurred where large neighbor trees were absent, a condition maintained primarily by elephants browsing and damaging large neighbor trees. Finally, I found that saplings conditioned by pre-fire wildlife “browsing legacies” had high tolerance to combined fire and wildlife browsing. These results help explain how saplings tolerate repeated tissue loss to disturbance. Understanding how interactions between fire and herbivory affect sapling recruitment will help managers effectively use natural disturbance processes to manage savanna structure and function.
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Gibeau, Daniel G. "Missile Design PC TRAP : an improved PC TRAP for tactical missile design /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA277215.
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Thesis (M.S. in Aeronautical Engineering and Aeronautical and Astronautical Engineer) Naval Postgraduate School, September 1993.Thesis advisor(s): Conrad F. Newberry. "September 1993." Bibliography: p. 309. Also available online.
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Tentu, Nagalakshmi. "Development of a laminar construction quadrupole ion trap." ScholarWorks@UNO, 2005. http://louisdl.louislibraries.org/u?/NOD,270.
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Thesis (M.S.)--University of New Orleans, 2005.Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Chemistry"--Thesis t.p. Vita. Includes bibliographical references.
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Wickramasinghe, Liat Piyum. "A study of the activity and species richness of British bats and their insect prey on organic and conventional farms using acoustic survey methods." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/ce0a0186-a1bb-4249-8949-f41a3f7b9481.
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許哲碩 and Chik-shek Enesco Hui. "Peak Tram Station: extension." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31985749.
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Tsampardoukas, Christos. "Ion trap quantum computing." Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/10704.
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Richard Feynman first proposed the idea of quantum computers thirty years ago. Since then, efforts have been undertaken to realize large-scale, fault-tolerant quantum computers that can factor large numbers much more quickly than classical computers, which would have significant implications for computer security. While there is no universally agreed upon technology for experimentally realizing quantum computers, many researchers look to ion traps as a promising technology. This thesis focuses on ion traps, how they fulfill the Divincenzo criteria, what obstacles must be overcome, and recent achievements in this field. We examine the physical principles of a linear Paul trap, including the confining potential and its quantum dynamics. In addition, we built a mechanical analogue of an ion trap for pedagogical purposes, and we provide an analysis of its trapping potential and compare it to a real ion trap, the Paul trap. Furthermore, we provide guidance for building a course module on ion trap based quantum computing; our guidance is based on course materials from several institutions.
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Kalbassi, Mohammed Ali. "Distillation sieve tray efficiencies." Thesis, University of Nottingham, 1987. http://eprints.nottingham.ac.uk/13540/.
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The distillation point efficiencies for the alcohol-water binary, ternary and quaternary systems were measured using a modified Oldershaw column. This column is expanded above the tray to separate the newly formed bubbles from the column wall, thus eliminating the surface tension induced wall effects for positive systems and discouraging wetted wall effects. The excessive and recirculating foam and froth found in the conventional Oldershaw column is due to these wall effects and does not represent conditions in large scale distillation. The point efficiencies measured using this column for the system methanol/water were lower than the point efficiencies deduced from the composition profiles across a large and narrow rectangular distillation column using an eddy diffusion model. The narrow rectangular column had a liquid flow path length of about one meter, thus avoiding stagnant zones and flow non-uniformities. The lower efficiencies were due to the shorter contact time between the gas and the liquid. This contact time was increased markedly by fitting an outlet weir to the modified Oldershaw column, thus increasing the tray liquid hold-up and the point efficiencies. These point efficiencies were about 10 per cent lower than those on the large tray at a similar value of the F. Factor. The eddy diffusion model predicted rectangular tray efficiencies about 10 to 20 per cent lower than those measured, when using the improved modified column point efficiencies. Using a suitable model, the improved point efficiencies were scaled-up to the conditions existing on the rectangular tray. This resulted in the large tray values of 2 to 4 per cent lower tray efficiencies than those measured. The surface tension effect on the point efficiencies of the binary systems MeOH/n.PrOH using the original modified Oldershaw column in the absence of wall effects using the concept of the Marangoni stabilising index. The surface tension of these systems were measured using a glass thermometer. The system MeOH/H20 had the highest Marangoni index and showed the highest point efficiencies throughout the composition range, with the EtOH/H2O/n.PrOH, with low values of the Marangoni index, showed comparable point efficiencies throughout the composition range. These systems demonstrate all the possible types of surface tension behaviour. The effects of the outlet weir height and hole size on the point efficiencies in the rectangular column operating under similar hydrodynamic conditions were also investigated using the system MeOH/H2O. There was an increase in point and tray efficiencies on increasing the outlet weir height from 2 mm to 12.7 mm. There was also small increase in point and tray efficiencies on decreasing the hole size from 6.4 mm to 1 mm at the expense of higher pressure drops. The point efficiencies of these trays under different hydraulic conditions were in the range 85 to 95 per cent, with subsequent high tray efficiencies. This provides further evidence of the high tray efficiencies available to the design engineer if the detrimental effects of stagnant zones and flow non-uniformities were eliminated. Two highly non-ideal ternary systems and quaternary system were also studied using the original modified Oldershaw and the rectangular columns. Considerable differences between the individual component point efficiencies were observed. These differences are probably caused by the interactive nature of the mass transfer in these systems. These systems also exhibited equal component point efficiencies in parts of the composition range, which illustrates the composition dependency of these systems. The individual component tray efficiencies for these systems were noticeably different, even with equal component point efficiencies operating across the tray. These differences were simulated using the eddy diffusion model, highlighting the effects of limited liquid back mixing on the tray. The composition profile for the system MeOH/EtOH/H20 were predicted and compared with the measurements across the rectangular column using three methods derived from the original Maxwell and Stephan mass transfer equations. These predictions were in good agreement with the measurements. However, as the comparison is only based on a one meter flow path length, the actual design of distillation column using these methods would be conservative. The prediction of the composition profiles using the point efficiencies from the original version of the modified 0ldershaw column yielded a similar observation for both the ternaries and the quaternary system. An expanded aluminium tray (Expamet 607A) was also subject to preliminary efficiency tests in the rectangular column. This material has corrugated angled holes, thus encouraging the liquid flow across the tray by using the vapour momentum. This material showed much lower pressure drops, due to its high open area compared with conventional sieve trays, and discourages weeping and entrainment.
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Hermansson, Alex, and Frida Cronqvist. "Flödesmekaniska modeller av trak." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195700.
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When planning for road building and infrastructure, simulations of tra-c ow are useful tools for further investigation. Two models are analyzed in this report, both supported by the assumption that tra-c ow behaves as a continous uid on a macroscopic scale. This means that the vehicle density will be considered instead of observing the vehicles as discrete objects. Conservational laws along with piecewise constant initial data are called Riemann problems. Tra-c ow in one dimension at a tra-c light can be modeled as such a problem with the continuity equation and a scaled Heaviside function as initial data. Two special cases of the general problem are solved, in the rst model the velocity of the cars is a linear function of the density while in the second model the velocty is a function of the denisty and its derivative. The rst case is solved analytically with a similarity solution. The second case, where diusion is included, is solved numerically and the method utilized is proved to be stable. Simulations are presented in order to see how the density of vehicles develop in front of and after the tra-c light. The results are used to determine a time for the tra-c light to be green, given a xed time for red, that optimzes the ow of vehicles.
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Kalra, Rita Rani. "An Improved Antihydrogen Trap." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:14226066.
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The recent demonstration of trapped atomic antihydrogen for 15 to 1000 seconds is a milestone towards precise spectroscopy for tests of CPT invariance. The confinement of a total of 105±21 atoms in a quadrupole magnetic trap was made possible by several improved methods. Improved accumulation techniques give us the largest numbers of constituent particles yet: up to 10 million antiprotons and several billion positrons. A novel cooling protocol leads to 3.5 K antiprotons, the coldest ever observed. Characterizing and controlling the geometry and density of these confined antimatter plasmas allow for consistency in antihydrogen production. Continued use of these methods along with the larger trap depth of a unique second-generation magnet are expected to yield greater numbers of trapped antihydrogen. The new magnet generates both quadrupole and octupole trap geometries, which should make it possible to reduce charged particle loss and will prove useful for laser cooling and spectroscopy. The ultra-low inductances of the magnet have been shown to vastly reduce turn-off times, which will optimize single-atom detection. Finally, improved detector characterization already makes us sensitive to smaller numbers of trapped antihydrogen atoms than before.
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Hui, Chik-shek Enesco. "Peak Tram Station : extension /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25950319.
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Prekop, Michal. "Most přes železniční trať." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409776.
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Diploma thesis is focused on a design of the road bridge of the category S7,5 in cadastral territory of a municipality Polanka nad Odrou. Three preliminary studies have been proposed. Box girder beam with a slant walls were selected for more detailed processing. Construction of the bridge is going to be build by time-dependent analysis on a solid formwork. The calculation of load is done by using computer software Midas Civil 19 v 2.1. and Scia Engineer 19.1. Selected preliminary was assessed according to the recent Europan standards.
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Cvengroš, Ján. "Webová prezentace běžeckých tras." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226353.
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This thesis deals with creating a web application that allows to upload and present information concerning running paths in Brno and its neighborhood. It consists of a user interface that provides the ability to manage information stored in the SQL database. It also serves as a tool for the automated determination of geometric parameters of tracks and allows you to view the routing on the map server mapy.cz or to portray the longitudinal profile.
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Drašková, Tereza. "Most přes železniční trať." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226433.
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Subject of this master-thesis is perpendicular bridging over „railway “ČD Břeclav – Přerov v km 180,287 033.Its content is the design of the construction of the bicameral multipole concrete bridge. The chosen option is formed by two additionally prestressed chambers connected by slab. The total length of 10-pin bridge is 307,20 metres. The calculation of effects of the load is done by software NEXIS. The assessment of construction is done manually according to standard ČSN-EN 1992-1-1. The calculation is done including time analysis.
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Martinez, Pedro. "Ion accumulation in a Paul trap for the Canadian Penning Trap Mass Spectrometer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0024/MQ50831.pdf.
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