81 |
Investigation of Symmetry and Electronic Effects in Asymmetric Palladium-Catalysed Allylic SubstitutionsStranne, Robert January 2001 (has links)
No description available.
|
82 |
Regulation of Inflammatory ProteinsMaria Halili Unknown Date (has links)
Inflammation involves a complex interplay of immunological responses in reaction to an infection from invading pathogens and to tissue injury. However, if the inflammatory stimulus is not eliminated or if there is an aberrant response, chronic inflammation and disease can result. Most inflammatory diseases are targeted by drugs that provide only symptomatic relief by reducing the associated pain and swelling, without combating the underlying cause and progression of the disease. The purpose of this thesis was to investigate potential drug targets in different sub-cellular compartments to learn more about inflammatory pathways and the consequences of inhibiting them using different classes of small-molecule agents. Chapter 1 is a brief overview of inflammation, outlining differences between acute and chronic inflammation in relation to normal and aberrant immune responses. Major drug classes that are currently in use are briefly discussed, and some potential new inflammatory drug targets in the nucleus, cytoplasm, plasma membrane and serum that are to be investigated in the thesis are described. Chapter 2 addresses histone deacetylase (HDAC) enzymes that modulate gene transcription, and investigates the regulatory potential of HDACs and their inhibitors in macrophages. Mainly murine macrophages were investigated, but preliminary data on human macrophages is also presented. Four kinds of small-molecule inhibitors of HDAC enzymes are described in relation to their capacity to exhibit pro- or anti- inflammatory gene expression. Broad-spectrum inhibitors, those that do not discriminate between different isoforms of HDACs, were found to induce expression of a number of pro-inflammatory mediators. This was also the case for compounds that selectively inhibit class-I HDACs. On the other hand, compounds that are known to selectively inhibit class-II HDACs did not regulate pro-inflammatory genes and could be classified as anti-inflammatory based on their profiles of gene expression. An inhibitor of class-III HDACs, the sirtuins, was also briefly investigated for anti-inflammatory gene expression. This separation of the pro- and anti-inflammatory responses suggested that specific inhibitors of class II HDACs might be promising for treating inflammatory conditions. Chapters 3 and 4 discuss a group of extracellular serum proteins that are produced through the complement pathway. Complement proteins circulate in plasma while some are formed on membranes through serine protease action, and effect both innate and adaptive immune responses. Chapter 3 deals with the alternative pathway (AP) of complement activation, in particular with the protease Factor B which plays an important role as part of a protein complex (C3 convertase) in the initiation and propagation of complement. Factor B is an inactive zymogen at pH 7, but is catalytically active at alkaline pH. Substrate-based inhibitors were developed for Factor B using a chromogenic assay previously optimised in our lab. Over 60 peptide aldehydes were evaluated, with two potent inhibitors of Factor B studied further, and were found to inhibit C3 convertase by blocking cleavage of the native substrate C3 as measured by SDS-PAGE. Chapter 4 examined the properties of a homologue of Factor B found in the classical pathway (CP), the protease C2. C2 was found herein to be an inactive zymogen at pH 7. Under alkaline conditions C2 cleaved both C3 and short chromogenic peptide substrates. Substrates of 7- or 8-residues, corresponding to those in the native substrate C3, were optimally processed. C2 was inhibited by inhibitors identified in Chapter 3, which also inhibited formation of the different C3 convertase formed through the CP, as well as preventing formation of the terminal membrane attack complex (MAC) as measured by an immobilized ELISA and haemolysis assay. The selectivity of small-molecule peptidic inhibitors for different serine proteases was investigated. Chapter 5 introduces two other unrelated inflammatory proteins which have been incompletely studied herein. Protease-activated receptor 2 (PAR-2) is a cell surface protein that spans the membrane like other G-protein coupled receptors. PAR-2 has been implicated in inflammatory and proliferative diseased states, though its precise roles are still unclear. Here, PAR-2 mRNA expression was measured for different human cancer and immune cells. In macrophages, PAR-2 mRNA expression was inducible by HDACi, indicating that PAR-2 is negatively regulated by HDAC enzymes. The receptor was present and functional on the surface of HDACi-treated macrophages, permitting evaluation of PAR-2 agonists and antagonists. Caspase-1 is a cytosolic cysteine protease responsible for cleaving proIL-1β and proIL-18 into their active forms that are then secreted from cells as pro-inflammatory cytokines. Using monocytic cells, novel inhibitors of caspase-1 were developed and found to dose-dependently decrease levels of IL-1β released by the cell. Inhibition of caspase-1 may be useful for modulating circulating levels of the inflammatory cytokine IL-1β. The investigation of different prospective inflammatory targets in different locations of the cell has provided a lateral overview of inflammatory mechanisms and drug intervention strategies. Specific inhibitors have also been identified for these targets; HDACs in the nucleus, caspase-1 in the cytosol, PAR-2 and MAC on the cell surface, C2 and Factor B and C3 convertase in plasma. This unconventional study of the inflammatory network provides a different viewpoint of inflammatory proteins as drug targets.
|
83 |
Realistic Extensible Generic Simulation Engine for Target Simulation in a Command and Control Training EnvironmentLundström, Isak January 2024 (has links)
This thesis explores the design and implementation of a simulation framework created for C2 training environments, focusing on simulating the movement of aircraft and other moving targets between waypoints. The core objective was to develop an extensible, reliable, and realistic simulation system that can adapt to simulate a variety of entities, each characterized by unique movement patterns defined by their type. The simulated input scenarios involve a collection of targets, where each target traverses through a defined set of waypoints according to their specified movement behavior at initialization. The research involved a evaluation of established theories and ideologies of both aircraft and computer simulation, leading to the creation of a framework that leverages Java for its scalability and performance. The framework was designed from the ground up to promote extensibility of various types of moving targets beyond of just that of aircraft, such as helicopters, boats, missiles, and surface vehicles. The accuracy of the simulation was tested by comparing its output to real-world flight data, demonstrating its capability to mimic realistic aircraft movement within predefined training scenarios. Additionally, the system's extensibility is showcased by simulating two different categories of aircraft—a commercial airliner and a small fighter jet—and illustrating the differences in their generated trajectories. Another outcome is the framework's ability to support real-time simulation, crucial for training scenarios in a C2 context. The system integrates and utilizes concurrent design techniques and dependable design patterns to ensure high throughput and performance, even when scaling to large numbers of targets. The framework's architecture allows for future extension and integration of new target types, without requiring modifications to the existing codebase, by the utilization of Javas SPI.
|
84 |
Data Flow and Remote Control in the Telemetry Network SystemLaird, Daniel T., Morgan, Jon 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The Central Test and Evaluation Investment Program (CTEIP) Integrated Network Enhanced Telemetry (iNET) program is currently developing new standards for wired-wireless local area networking (LAN-WLAN) using the Internet Protocol (IP), for use in telemetry (TM) channels, under the umbrella of the Telemetry Network System (TmNS). Some advantages of TmNS are real-time command and control of instrumentation, quick-look acquisition, data retransmission and recovery ('gapless TM' or 'PCM backfill'), data segmentation, etc. The iNET team is developing and evaluating prototypes, based on commercial 802.x and other technologies, in conjunction with Range Commander's Council (RCC) Inter-Range Instrumentation Group (IRIG) standards and standards developed under the iNET program.
|
85 |
Psychological antecedents of suicidal behaviorCameron, Shri January 2013 (has links)
While research highlights a number of risk factors for suicide, not all individuals displaying these characteristics will go on to attempt suicide. Depressed mood is a proximal indicator of suicide, with deterioration in already depressed mood increasing the likelihood of a suicide attempt. The overall aim of this thesis was to empirically test the Cognitive Model of Suicide by Wenzel and Beck (2008). This model proposes that each of the three components, dispositional vulnerabilities, mood disturbance and suicide related cognitions, may influence each other to enhance the propensity for a suicidal crisis. The thesis starts by examining the relationship between two personality characteristics (neuroticism and trait aggression) and current depressed mood, and then focuses on the relationship between suicidality and current depressed mood. Although autobiographical memories have been implied as a possible risk factor for suicidality, meta-analytical studies have highlighted discrepancies between sampling techniques which may limit interpretablity. Therefore, the first series of studies aimed to establish a protocol for assessing autobiographical memories. The second and third series of studies aimed to investigate whether the relationships between current depressed mood and specific personality factors (neuroticism and trait aggression) were indirectly influenced by other known risk factors that may affect cognitive processing of information (rumination, overgenerality, impulsivity). Moreover, these studies aimed to determine whether the same cognitive processing factors effected current depressed mood in non-suicidal and suicide attempt groups. The final series of studies aimed to determine whether these risk factors (neuroticism, trait aggression, brooding, impulsivity, and overgenerality) mediated the relationship between suicidality and current depressed mood. Findings indicated that compared to the non-suicidal group, individuals in the suicide attempt group was more likely to be influenced by the effects of trait aggression and brooding, and that the combination of these factors were positively associated with current depressed mood. In contrast, neuroticism and impulsivity appeared to influence individuals who had experienced suicidal ideation more than individuals who report never having suicidal thoughts or attempting suicide. Compared to the non-suicidal group, however, neuroticism and impulsivity did not show a significant association for current depressed mood in the suicidal ideation group. Findings supported the Interacting Sub-Systems model and are discussed in relation to the Cognitive Model of Suicide model.
|
86 |
Charakterizace vedlejší populace buněčné linie TRAMP-C2, myšího modelu karcinomu prostaty" / Characterisation of the cell line TRAMP-C2 side population, mouse model of prostate cancerŽlabová, Anna January 2012 (has links)
Side population is a minor subpopulation (SP) of some cell lines, exporting staining dye Hoechst 33342 out of their cytoplasm. It is discussed as a possible source of "cancer stem cells", "tumour initiating cells" or "metastasis initiating cells". However, broad literature suggest, that stemness and other privileged properties of SP are very variable between different cell types, cell lines and stage of disease. Cell lines TRAMP are the only widely available murine models for testing of prostate cancer therapy. We noticed in literature a mention about existence of 1-2% of cells constituting side population, but detailed characteristic have not been described until now. In this diploma thesis, we worked on characterisation of SP of the TRAMP-C2 cell line in comparison to other cells (nonSP). In the first part, we compared stem properties of SP and nonSP. We started with checking the existence of SP by its verapamil sensitivity. Using mRNA analysis, we showed that neither SP nor nonSP have increased c-Kit expression and that there are no differences in Bmi-1 expression. We found that SP is heterogenic mixture of CD24-CD44-, CD24-CD44+ and CD24+CD44+ cells, while nonSP is almost solely CD24-CD44+. We documented that SP and nonSP returned back to original SP ratio during cultivation. Then we showed on...
|
87 |
Navios-aeródromo e a aviação embarcada na estratégia naval brasileira // Eduardo Italo Pesce; orientador: Francisco Eduardo Alves de AlmeidaPesce, Eduardo Italo January 2016 (has links) (PDF)
Orientador: Francisco Eduardo Alves de Almeida. / Dissertação (mestrado) - Escola de Guerra Naval, Programa de Pós-Graduação em Estudos Marítimos (PPGEM), Rio de Janeiro, 2016. / Graduação em Estudos Marítimos (PPGEM), Rio de Janeiro, 2016. / Bibliografia: f. 185-205 / O objetivo desta dissertação é averiguar se a existência do navio-aeródromo (NAe) e da aviação embarcada é compatível com a Estratégia Naval Brasileira atual. O foco do texto está nos NAe capazes de operar com aeronaves de asa fixa, mas este também mencio / The objective of this thesis is to investigate whether an aircraft carrier and carrier-based aircraft are compatible with the current Brazilian naval strategy. The focus is on carriers capable of fixed-wing aircraft operation, but big-deck amphibious assa / Made available in DSpace on 2018-02-14T18:06:19Z (GMT). No. of bitstreams: 0
Previous issue date: 2016. Added 1 bitstream(s) on 2019-02-13T19:30:13Z : No. of bitstreams: 1
00001567.pdf: 3188533 bytes, checksum: 8d379fae5673b0d6364b31a3b93bc4a6 (MD5)
|
88 |
ASSESSING THE MODEL FIT OF MULTIDIMENSIONAL ITEM RESPONSE THEORY MODELS WITH POLYTOMOUS RESPONSES USING LIMITED-INFORMATION STATISTICSLi, Caihong Rosina 01 January 2019 (has links)
Under item response theory, three types of limited information goodness-of-fit test statistics – M2, Mord, and C2 – have been proposed to assess model-data fit when data are sparse. However, the evaluation of the performance of these GOF statistics under multidimensional item response theory (MIRT) models with polytomous data is limited. The current study showed that M2 and C2 were well-calibrated under true model conditions and were powerful under misspecified model conditions. Mord were not well-calibrated when the number of response categories was more than three. RMSEA2 and RMSEAC2 are good tools to evaluate approximate fit.
The second study aimed to evaluate the psychometric properties of the Religious Commitment Inventory-10 (RCI-10; Worthington et al., 2003) within the IRT framework and estimate C2 and its RMSEA to assess global model-fit. Results showed that the RCI-10 was best represented by a bifactor model. The scores from the RCI-10 could be scored as unidimensional notwithstanding the presence of multidimensionality. Two-factor correlational solution should not be used. Study two also showed that religious commitment is a risk factor of intimate partner violence, whereas spirituality was a protecting factor from the violence. More alcohol was related with more abusive behaviors. Implications of the two studies were discussed.
|
89 |
Etude des mécanismes de désexcitation de C60 : ionisation retardée et émission C2Climen, Bruno 11 July 2006 (has links) (PDF)
Cette thèse est consacrée à l'étude des mécanismes de refroidissement du fullerène C60 après une excitation laser nanoseconde. Dans ce régime temporel, l'énergie absorbée est redistribuée sur tous les degrés de liberté de l'agrégat provoquant une cascade de fragmentations par émission de molécules C2. Un processus d'ionisation retardée est mis en évidence pour chaque taille d'agrégat produit. Les cations ainsi formés peuvent à leur tour se fragmenter par émission de C2. Notre dispositif expérimental, constitué d'un spectromètre à imagerie résolu en temps type velocity-map combiné à un spectromètre de masse à temps de vol type Wiley-McLaren, permet d'extraire les spectres en énergie cinétique des photoélectrons ou des photoions issus de la chaîne de désexcitation de C60. Ces spectres sont comparés à un modèle statistique basé sur le formalisme de Weisskopf. Un algorithme Monte Carlo a été développé afin de reconstituer le spectre de temps de vol de C60. Les informations extraites des simulations, tels les énergies internes et les rapports de branchement à chaque étape du déclin, complètes idéalement l'analyse des processus mis en jeu.
|
90 |
Protein engineering to explore and improve affinity ligandsLinhult, Martin January 2003 (has links)
In order to produce predictable and robust systems forprotein purification and detection, well characterized, small,folded domains descending from bacterial receptors have beenused. These bacterial receptors, staphylococcal protein A (SPA)and streptococcal protein G (SPG), possess high affinity to IgGand / or HSA. They are composed of repetitive units in whicheach one binds the ligand independently. The domains foldindependently and are very stable. Since the domains also havewellknown three-dimensional structures and do not containcysteine residues, they are very suitable as frameworks forfurther protein engineering. Streptococcal protein G (SPG) is a multidomain proteinpresent on the cell surface ofStreptococcus. X-ray crystallography has been used todetermine the binding site of the Ig-binding domain. In thisthesis the region responsible for the HSA affinity of ABD3 hasbeen determined by directed mutagenesis followed by functionaland structural analysis. The analysis shows that the HSAbindinginvolves residues mainly in the second α-helix. Most protein-based affinity chromatography media are verysensitive towards alkaline treatment, which is the preferredmethod for regeneration and removal of contaminants from thepurification devices in industrial applications. Here, aprotein engineering strategy has been used to improve thetolerance to alkaline conditions of different domains fromprotein G, ABD3 and C2. Amino acids known to be susceptibletowards high pH were substituted for less alkali susceptibleresidues. The new, engineered variants of C2 and ABD shownhigher stability towards alkaline pH. Also, very important forthe potential use as affinity ligands, these mutated variantsretained the secondary structure and the affinity to HSA andIgG, respectively. Moreover, dimerization was performed toinvestigate whether a higher binding capacity could be obtainedby multivalency. For ABD, binding studies showed that divalentligands coupled using non-directed chemistry demonstrated anincreased molar binding capacity compared to monovalentligands. In contrast, equal molar binding capacities wereobserved for both types of ligands when using a directed ligandcoupling chemistry involving the introduction and recruitmentof a unique C-terminal cysteine residue. The staphylococcal protein A-derived domain Z is also a wellknown and thoroughly characterized fusion partner widely usedin affinity chromatography systems. This domain is consideredto be relatively tolerant towards alkaline conditions.Nevertheless, it is desirable to further improve the stabilityin order to enable an SPA-based affinity medium to withstandeven longer exposure to the harsh conditions associated withcleaning in place (CIP) procedures. For this purpose adifferent protein engineering strategy was employed. Smallchanges in stability due to the mutations would be difficult toassess. Hence, in order to enable detection of improvementsregarding the alkaline resistance of the Z domain, a by-passmutagenesis strategy was utilized, where a mutated structurallydestabilized variant, Z(F30A) was used as a surrogateframework. All eight asparagines in the domain were exchangedone-by-one. The residues were all shown to have differentimpact on the alkaline tolerance of the domain. By exchangingasparagine 23 for a threonine we were able to remarkablyincrease the stability of the Z(F30A)-domain towards alkalineconditions. Also, when grafting the N23T mutation to the Zscaffold we were able to detect an increased tolerance towardsalkaline treatment compared to the native Z molecule. In allcases, the most sensitive asparagines were found to be locatedin the loops region. In summary, the work presented in this thesis shows theusefulness of protein engineering strategies, both to explorethe importance of different amino acids regarding stability andfunctionality and to improve the characteristics of aprotein. <b>Keywords:</b>binding, affinity, human serum albumin (HSA),albumin-binding domain (ABD), affinity chromatography,deamidation, protein A, stabilization, Z-domain, capacity,protein G, cleaning-in-place (CIP), protein engineering, C2receptor.
|
Page generated in 0.0481 seconds