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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.
51

TESTING ALTERNATIVE METHODS TO CALCULATE USER TOLLS ON I-95 EXPRESS LANES

Unknown Date (has links)
Nowadays, there is increasing number of facilities that implement various pricing strategies in order to manage increasing traffic demand. Most of these strategies use traffic data collected on several points in the system, aggregate them in certain aggregation interval and calculate tolls based on them. Some strategies derive performance measures (as traffic density) based on aggregated data, and define tolls. However, derived performance measures tend to underestimate traffic conditions and data aggregation interval can smooth traffic data. On the other hand, travel time has not been utilized in order to calculate user tolls on such systems, and yet it can directly measure users delay in the system, and directly capture field conditions. In addition, technology to collect travel times is becoming more popular and used in transportation systems. Hence, this study aims to test alternative methods for toll calculation that will rely on travel time data and compare their performance with currently utilized toll calculation algorithm on I-95 Express lanes in South Florida. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
52

Regulation und Signaltransduktion der Toll-like-Rezeptoren in humanen Plazentazellen /

Klaffenbach, Daniela. Unknown Date (has links)
Erlangen, Nürnberg, Universiẗat, Diss., 2007. / Enth. 1 Sonderabdr. aus: American journal of reproductive immunology ; Vol. 53. 2005. - Beitr. teilw. dt., teilw. engl.
53

Network Based Evaluation Method for Financial Analysis of Toll Roads

Vajdic, Nevena 2009 December 1900 (has links)
The design, build, finance and operation of public infrastructure is becoming increasingly dependent on participation of the private sector. An imposing amount of investment involved in a public private partnership agreement places financial institutions in the role of major lenders. The complexity of these agreements creates a gap in the information flow between the public sector, the private sector and financial institutions as project participants. Additionally, the public sector decisions about the network improvement actions add to the complexity of these agreements. The objective of this research is to develop a method which will allow an assessment of the effect that network improvement actions have on the project’s financial feasibility. Three common financial instruments were analyzed: bank loans, bonds and real options. Emphasis of the financial feasibility assessment was on the price of the revenue risk, as the most important risk in public private partnership agreements. Results have shown that network improvement actions can have significant impact on the price of the revenue risk. The magnitude of the impact depends on the type of instrument and the position of the road link in the network.
54

Priming Response and Toll-like Receptors Expression in Inflammatory Cells

Huang, Hau-lun 26 August 2005 (has links)
Burns often leads to infection, due to damage to the skin's protective barrier. Burn injury has been repeatedly shown to induce considerable inflammatory and immune dysfunction. The innate immune system is a universal and ancient form of host defense against infection. Activation of innate immunity constitutes the first line of host defense against infection. Neutrophils are white blood cells and part of the immune system. They are the most common PMN (polymorphonuclear neutrophils) and accounted for 70% of all leukocytes. Neutrophils provided the first line of defense of the innate immune system by phagocytosing, killing, and digesting bacteria and fungi. Priming means a process whereby the response of neutrophils to an activating stimulus is potentiated, sometimes greatly, by prior to exposure to priming agents such as tumor necrosis factor-alpha(TNF-alpha), platelet-activating factor (PAF). Neutrophil priming causes a dramatic increase in the response of these cells to an activating agent; this process has been shown to be critical for neutrophil-mediated tissue injury both in vitro and in vivo. However, the intracellular signaling pathways used by neutrophil in response to pro-inflammatory stimuli have not been elucidated. The discovery of TLRs has made us understanding of the mechanisms of innate immune recognition. The innate immune system detectes the invasion of microorganism through TLRs, which recognize microbial components and trigger inflammatory responses. Severe burn injury produces shock and induces acute gastrointestinal derangement that may disrupt gastrointestinal mucosa integrity and facilitate the bacterial translocation (BT) to Mesenteric lymph node (MLN), liver, and spleen. Hypertonic saline (HTS) has been advocated in thermal injury resuscitation because of the possibility of giving less total volume of resuscitation fluid, with a resulting decrease in edema and the need for escharotomy. In this study, I found that priming effect of BM neutrophils is TNF-alpha and p38 dependent and TLRs play a critical role to the innate immunity by recognizing bacteria and HTS enhance host response to bacterial challenge by increasing TLRs of inflammatory cells.
55

Intestinal microflora induce host defense after burn through Toll-like Receptor 4 signaling in mice

Chang, Wei-Jung 23 January 2007 (has links)
The most abundant microflora is present in the distal parts of gut and the majority of the bacteria are Gram-negative anaerobes. Toll-like receptor 4 (TLR4), one of the ¡§pathogen-recognition molecules¡¨, recognize the lipopolysaccharide (LPS), derived from Gram-negative bacteria. TLR4 recognized the intestinal microflora and triggers the inflammatory responses. Although the effect of intestinal microflora on enhancing host to response the challenge from bacteria has been established, the mechanism has not been well studied. In this study, the relationship between TLR4 expression and the inflammatory response under intestinal microflora depletion was investigated. Mice fed with antibiotics for 4 weeks to delete the intestinal commensals and supplemented with or without LPS to stimulate TLR4 at week 3 were under sham or burn treatment. Results showed that thermal injury intestinal permeability, bacterial translocation to mesenteric lymph nodes, and neutrophil deposition in lung. Also, the activation of NF-£MB, expression of HSP70 and TLR4 were induced in intestinal after thermal injury. Moreover, TLR4 expression was increased in lung and peritoneal cells, ICAM and TNF-£\ expression were increased in peritoneal cells after thermal injury. However, NF-£MB activation, expression of TLR4, ICAM, and HSP70 were decreased in intestinal mucosa of mice with microflora depletion after thermal injury. Microflora depletion also significantly decreased the MPO activity in lung, and the phagocytic activity, the TLR4, ICAM, and TNF-£\ expression of peritoneal cells after thermal injury. Interestingly, LPS supplement reversed the effect of microflora depletion, suggest that intestinal microflora can trigger the host defense through TLR4 signaling pathway in thermal injured mice.
56

Optimal road pricing in transportation networks /

Zhang, Xiaoning. January 2003 (has links)
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 230-240). Also available in electronic version. Access restricted to campus users.
57

Implications of uncertain future network performance on satisfying environmental justice and tolling

Duthie, Jennifer Clare, 1981- 12 October 2012 (has links)
This dissertation is concerned with developing new methods for exploring the pressing problems of uncertainty, Environmental Justice, and tolling as they relate to long-range transportation planning. While these topics are seemingly disparate, much of the work in this dissertation is motivated by the increasing number of roadway projects concessioned to the private sector, and the lack of tools available for evaluating the impact of such agreements on the public given high levels of uncertainty over the length of the contracts and concern for the welfare of traditionally underserved population groups. These issues will be considered separately and together, offering insights into how transportation investment decisions can be improved. To this end, the impacts of considering long-range uncertainty in the traffic assignment model as well as in an integrated transportation and land use model (ITLUM) are assessed in terms of the effects on network performance measures and roadway improvement decisions. A new method for accounting for correlations between the future travel demands of origin-destination zone pairs is developed for the traffic assignment problem that can more effectively model the effects of potential economic changes. Results showed that neglecting correlations can lead to measures of variance of future total system travel time that range from underestimating the actual measure by seventy-five percent to overestimating it by one hundred percent, and to different selections for a network improvement project in up to fifty percent of all scenarios. Uncertainty in a basic ITLUM is considered more broadly, incorporating probability distributions for population and employment inputs as well as several travel demand model parameters, and examining how the choice of performance measure impacts the effect of uncertainty on the decision of where to increase system capacity. Comparing the network improvement projects selected when uncertainty is considered to a deterministic analysis, showed differences in up to 25% of scenarios. Challenges of considering Environmental Justice, a type of group-based equity that is required for metropolitan transportation plan compliance in the United States, are explored, particularly with regard to appropriately defining the term equity for the analysis. Several of these potential definitions are then transformed into objective functions for use in a new formulation of the user equilibrium-based discrete network design problem. A multi-objective genetic-algorithm solution method is developed to solve the problem efficiently, and insights are revealed into how different definitions of equity can lead to different decisions. The following objectives, both commonly used in practice, were found to be conflicting: 1) minimizing the difference in post-improvement performance across populations and 2) minimizing the difference across populations in the change in performance due to improvements. The problem of roadway tolling is first examined from the perspective of a private sector toll road operator seeking to maximize the asset's value by exercising flexibility. A stochastic recourse model is developed to account for the first stage investment decision and the second stage decisions to alter network capacity and toll rates. The flexibility to engage in non-compete clauses whereby the public sector cannot improve competing roadways, and also to improve feeder links in the surrounding network were found to play important roles in asset valuation. The value of having these options was found to increase with an increase in uncertainty of future demand, complexity of network structure, and the consequence of failure to meet debt obligations. The three original issues of uncertainty, Environmental Justice, and tolling are woven together into the development of a new method for determining the maximum toll rate that can be applied in a private sector operation scenario (first option) such that each group within the population, as defined for analysis of Environmental Justice, is no worse off than if the road had been constructed by the public sector without tolling (second option). Three stochastic dominance criteria are implemented to find the toll rate at which the first option dominates the second given uncertainty about the future travel demand. Findings suggest that there may be many toll rates that equate the benefits resulting from the two options, so the minimum rate is considered the optimal one. The difference in benefits to the groups was found to increase with increasing value of time, and the differences in optimal toll rates using each of the three dominance criteria increased similarly. The analytical tools developed in this dissertation, and the resulting insights obtained should offer significant contributions to several areas of long-range transportation planning, particularly informing the process of concessioning roadways to private entities, developing a transportation system that is robust to future uncertainty, and ensuring that Environmental Justice criteria is met by considering the transportation needs of each group within the population. / text
58

The Role of Neu1 Sialidase in Toll-Like Receptor Activation

Amith, Schammim Ray 26 January 2009 (has links)
Receptor glycosylation is critical in receptor-ligand interactions in immune cells, but the exact role of glycosylation in receptor activation upon ligand binding has not been elucidated. In neuronal cells, we have shown that when neurotrophic factors bind their respective Trk tyrosine kinase receptors, receptor activation and subsequent neurotrophin-mediated signaling is dependent upon the induction and activity of an endogenous sialidase enzyme. In this thesis, we report that toll-like receptor (TLR) activation upon ligand binding is similarly dependent on the induction of a cellular sialidase, which we have identified as Neu1 sialidase, which specifically targets and hydrolyses alpha-2,3-linked sialic acid residues on the receptor. Blocking Neu1 sialidase activity with specific inhibitor Tamiflu detrimentally impacts ligand-induced TLR4/MyD88 interaction, NFkappaB activation and TLR-mediated effector responses like nitric oxide and pro-inflammatory cytokine production. Diminished cytokine production is also seen in vivo in Neu1-deficient mice. We propose a mechanism for the induction of Neu1 sialidase, upon ligand binding to TLR, that involves the activation of heterotrimeric G-alpha protein-dependent G-protein coupled receptor (GPCR) signaling to activate a matrix metalloproteinase (MMP) enzyme, likely MMP-9. It is suggested that MMP-(9) targets the cell surface elastin receptor complex of Neu1/protective protein cathepsinA/elastin binding protein (EBP), which potentially catalytically activates Neu1. In addition, we report an association between Neu1 and TLR2, TLR3 and TLR4 on the plasma membrane that has not previously been described. The idea that the multiple functionality and diversity of TLRs and TLR-mediated signaling may be an immunologic paradigm capable of explaining all human disease is provocative but plausible. Certainly, the structural integrity of TLRs, their ligand interactions and activation are essential for immunological protection. Thus, understanding the molecular mechanism of Neu1 sialidase regulation of TLR activation will provide important opportunities for disease control through TLR manipulation. The future directions of this research will also open a new area of glycobiology research (the glycomics of innate immune responses) and will widen the scope for the development of novel therapeutic drugs to combat infections and inflammatory diseases. / Thesis (Ph.D, Microbiology & Immunology) -- Queen's University, 2009-01-26 12:33:32.743
59

Systematische Analyse von Rezeptoren und Effektormechanismen der pulmonalen angeborenen Immunität

Stanze, Daniel. Unknown Date (has links)
Univ., Diss., 2009--Marburg.
60

Mechanismen der Mastzellaktivierung durch gram-negative Bakterien und Bakterienprodukte aus der Darmflora.

Krämer, Sigrid, January 2006 (has links)
Hohenheim, Univ., Diss., 2006.

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