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Gu, Ning. "Dynamic Designs of Virtual Worlds Using Generative Design Agents." Thesis, The University of Sydney, 2006. http://hdl.handle.net/2123/984.
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This research aims at developing a different kind of virtual world that is dynamically designed and implemented as needed. Currently, most virtual world designs are considered static. Similar to the physical world, these worlds are pre-defined prior to their use. The resultant environments serve certain purposes but do not take into consideration possible changes to the purposes during their use, changes which often occur when the occupants interact with the environments and with each other. Virtual worlds as networked environments can be flexibly configured and programmed. This flexibility makes it possible to consider virtual world designs in terms of dynamics and autonomy, reflecting the changing needs of different moments. To achieve dynamic designs of virtual worlds, this study applies a computational approach using rational design agents. A Generative Design Agent (GDA) model is developed that specifies computational processes for reasoning and designing in virtual worlds. The GDAs serve as personal design agents to the virtual world occupants. Design formalisms for virtual worlds are also addressed. The design component of a GDA is supported by the application of a generative design grammar. On one hand, generative design grammars serve as the generative force to be applied by the GDAs for virtual world design automation. On the other hand, each grammar defines coherent stylistic characterisations shared by the virtual world designs it generates. The technical outcomes of the research consist of the GDA model and a generative design grammar framework. The framework provides guidelines and strategies to designers for developing generative design grammars that produce different design languages for virtual worlds, rather than predefine every detail of all possible virtual world designs. GDAs monitor the virtual worlds and the various activities that occur in the worlds, interpret the occupants’ needs in the virtual worlds and the state of the worlds based on these observations, hypothesise design goals in order to satisfy these needs, and finally apply generative design grammars to provide virtual world designs for the moment, or initiate other actions in the worlds, according to the current design goals, on behalf of the occupants. The development of the GDA model and the generative design grammar framework provides new perspectives for understanding and developing virtual worlds. The GDA model challenges the conventional way that virtual worlds are designed and implemented, and this leads to dynamic designs of virtual worlds. The generative design grammar framework provides a computational approach to formally defining design languages for virtual worlds.
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Gu, Ning. "Dynamic Designs of Virtual Worlds Using Generative Design Agents." Architecture, 2006. http://hdl.handle.net/2123/984.
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Doctor of Philosophy (PhD)This research aims at developing a different kind of virtual world that is dynamically designed and implemented as needed. Currently, most virtual world designs are considered static. Similar to the physical world, these worlds are pre-defined prior to their use. The resultant environments serve certain purposes but do not take into consideration possible changes to the purposes during their use, changes which often occur when the occupants interact with the environments and with each other. Virtual worlds as networked environments can be flexibly configured and programmed. This flexibility makes it possible to consider virtual world designs in terms of dynamics and autonomy, reflecting the changing needs of different moments. To achieve dynamic designs of virtual worlds, this study applies a computational approach using rational design agents. A Generative Design Agent (GDA) model is developed that specifies computational processes for reasoning and designing in virtual worlds. The GDAs serve as personal design agents to the virtual world occupants. Design formalisms for virtual worlds are also addressed. The design component of a GDA is supported by the application of a generative design grammar. On one hand, generative design grammars serve as the generative force to be applied by the GDAs for virtual world design automation. On the other hand, each grammar defines coherent stylistic characterisations shared by the virtual world designs it generates. The technical outcomes of the research consist of the GDA model and a generative design grammar framework. The framework provides guidelines and strategies to designers for developing generative design grammars that produce different design languages for virtual worlds, rather than predefine every detail of all possible virtual world designs. GDAs monitor the virtual worlds and the various activities that occur in the worlds, interpret the occupants’ needs in the virtual worlds and the state of the worlds based on these observations, hypothesise design goals in order to satisfy these needs, and finally apply generative design grammars to provide virtual world designs for the moment, or initiate other actions in the worlds, according to the current design goals, on behalf of the occupants. The development of the GDA model and the generative design grammar framework provides new perspectives for understanding and developing virtual worlds. The GDA model challenges the conventional way that virtual worlds are designed and implemented, and this leads to dynamic designs of virtual worlds. The generative design grammar framework provides a computational approach to formally defining design languages for virtual worlds.
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Redij, Tejashree. "Rational Design of Anti-diabetic Agents." Thesis, University of the Sciences in Philadelphia, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13861629.
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The Glucagon-like peptide 1 receptor (GLP-1R) belongs to the pharmaceutically important Class B family of G-protein coupled receptors (GPCRs) and its incretin peptide ligand GLP-1 analogs are adopted drugs for the treatment of type 2 diabetes (T2D). Despite remarkable anti-diabetic effects, Glucagon Like Peptide-1 (GLP-1) peptide-based drugs are limited by the need of injection or high cost oral formulation. On the other hand, developing non-peptide small molecule drugs targeting GLP-1R remains elusive likely due to the large nature of the orthosteric binding site on GLP-1R. A promising approach is to develop small molecule agonistic positive allosteric modulators (ago-PAMs) or positive allosteric modulators (PAMs) of GLP-1R by targeting the potential allosteric sites in the transmembrane (TM) domain of human GLP-1R.
As the first step of taking this approach, we constructed a three-dimensional structure model of the TM domain of human GLP-1R using homology modeling and conformational sampling techniques. Next, a potential allosteric binding site on the TM domain was predicted computationally. In silico screening of drug-like compounds against this predicted allosteric site has identified nine compounds as potential GLP-1R agonists. The independent agonistic activity of two compounds was subsequently confirmed using cyclic adenosine monophosphate (cAMP) response element (CRE)-based luciferase reporting system. One compound was also shown to stimulate insulin secretion through in vitro assay. In addition, this compound synergized with GLP-1 to activate human GLP-1R.
In 2017, the crystal structures of GLP-1R in its active state (PDB ID: 5VAI) became available. Hence, we have performed another round of in silico screening employing this structure. First, the potential ligand binding sites in 5VAI were identified using computational tools and in silico screening procedure as described above was carried out again. A new small 8 molecule with low molecular weight and logP was identified. In vitro studies of this compound confirmed that it acts as the ago-Positive Allosteric Modulator (PAM) of GLP-1R that improves GLP-1's affinity and efficacy towards GLP-1R. When used in combination with GLP-1, this compound improves insulin secretion than using GLP-1 alone. Site specific mutagenesis studies confirmed its binding site as predicted in the TM domain of GLP-1R.
Finally, this ago-PAM molecule was further optimized to improve its potency and specificity towards GLP-1R using structure-based optimization strategy and medicinal synthesis. The newly designed compound, whose molecular weight was less than the parental compound, was found to act as the PAM of GLP-1R and showed improvement in the specificity than the parental compound. Thus, this new compound could be further exploited in the drug development for T2D treatment.
These results demonstrated that allosteric regulation exists in GLP-1R and can be exploited for developing small molecule agonists. The success of this work will help pave the way for small molecule drug discovery targeting other Class B GPCRs through allosteric regulations.
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Zrehen, Stéphane. "Elements of brain design for autonomous agents /." [S.l.] : [s.n.], 1995. http://library.epfl.ch/theses/?nr=1373.
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Okamoto, Masayuki. "Design and applications of learning conversational agents." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/148780.
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Arnold, Stephen John. "The design of agents against alzheimer's disease." Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536076.
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Khristova, Tetiana. "Computer-aided design of novel antithrombotic agents." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01018545.
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Thrombosis is the most important pathological process underlying many cardiovascular diseases, which are responsible for high mortality worldwide. In this theses the computer-aided design of new anti-thrombotic agents able to inhibit two types of receptors located on the surface of the platelets has been applied. The first one - αIIbβ3 - is responsible for the interaction of activated platelets with fibrinogen to form clots, whereas the second one - thromboxane A2 - is responsible for platelet activation by one of agonists excreted by activated platelets. To achieve this, different types of models have been developed using experimentally available information and structure of protein-ligand complexes. This concerns: QSAR models, structure-based and ligand-based 3D pharmacophore models, 2D pharmacophore models, shape-based and molecular field-based models. The ensemble of the developed models were used in virtual screening. This study resulted in suggestion of new potential antagonists of αIIbβ3 and thromboxane A2 receptors. Suggested antagonists of αIIbβ3 able to bind either open or closed form of the receptor have been synthesized and tested experimentally. Experiments show that they display high activity; moreover some of theoretically designed compounds are more efficient than Tirofiban - the commercialized drug molecule. The recommended antagonists of thromboxane A2 receptor have been already synthesized but biological tests have not been completed yet.
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De, Jager Josephus Jacobus. "Design and synthesis of novel antimalarial agents." Thesis, Stellenbosh : Stellenbosh University, 2014. http://hdl.handle.net/10019.1/96071.
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Thesis (MSc)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Malaria is a pestilent disease associated with massive socioeconomic burden of sub-Saharan Africa. This disease is caused by a blood infection of the single cellular parasite of the Plasmodium genus. Two enzymes of this parasite have been identified to be essential to the survival of this parasite, notably Spermidine Synthase and Protein Farnesyltransferase. The goal of this dissertation was to search for and synthesise novel inhibitors of these two enzymes with a strong focus towards understanding their structure/activity relationships. To achieve the first goal, molecular modelling was employed. An in-depth discussion is presented to describe the underlying principles relevant to this branch of computational chemistry. This ensures that the experiments using these methods are set-up correctly and results are interpreted within context. Two virtual high-throughput screens were then performed using prepared crystallographic structures of Spermidine Synthase. The first was pharmacophore based method and the second based on LibDock. The database used, containing 7.1 million compounds, was filtered using a custom developed tool prior to screening. Finally, CDOCKER was then used to investigate the activity of potential hit compounds. Spermidine Synthase has a natural affinity for adenosine and this trait was exploited by derivatising analogues to synthesise potential inhibitors of the enzyme. This was to be achieved by the incorporation of both electrophilic and nucleophilic moieties at selected positions, including the use of a high yielding Mitsunobu reaction. A number of additional residues were then synthesised and joined to the adenosine which were proposed to increase the active site occupancy and increase affinity to the enzyme. For the second enzyme targeted for inhibition, Protein Farnesyltransferase, indole was used as a starting scaffold to synthesise potential hits de novo. It was aimed to derivatise the indole at the Nʹ and 3ʹ positions. The crystal structure of one of the intermediates was published. Furthermore, a synthetic sequence which culminated in a palladium catalysed Suzuki coupling was performed.
AFRIKAANSE OPSOMMING: Malaria is ‘n peslike siekte wat geassosieer word met beduinde sosio-ekonomiese implikasies vir sub-Sahara Afrika. Die siekte word veroorsaak deur ‘n bloed infeksie van die enkel sellulêre parasiet van die Plasmodium genus. Twee ensieme, naamlik Spermidien Sintetase en Protein Farnesieltransferase, is geïdentifiseer om noodsaaklik te wees vir die oorlewing van die parasiet. Die doelwit van hierdie verhandeling is die soektog en sintese van oorspronklike inhibeerders van hierdie twee ensieme met ‘n sterk fokus daarop om struktuur/aktiwiteit interaksies te verstaan. Om die eerste doelwit te bereik is molekulêre modellering toegepas. ‘n Indiepte ondersoek word voorgestel om die onderliggende beginsels relevant tot hierdie tak van berekenkundige chemie te beskryf. Dit verseker dat eksperimente wat op hierdie tegnieke berus korrek opgestel word en dat die resultate binne konteks geïnterpreteer word. Twee virtuele hoë-deurset skerms was deurgevoer op voorbereide kristallografiese strukture van Spermidien Sintetase. Die eerste het berus op ‘n pharmakoforiese metode en die tweede op LibDock. ‘n Self-ontwikkelde sagteware gereedskap stuk is gebruik om a databasis van 7.1 miljoen verbindings te filtreer voor dit gebruik is in hoë-deurset skerms. Uiteindelik is CDOCKER gebruik om die potensiele aktiwiteit van “treffer” verbindings te beraam. Spermidien syntetase het ‘n natuurlike affiniteit vir adenosien en hierdie eienskap is benut deur analoeë af te lei na potensiële inhibeerders teen die ensiem. Dit is bewerkstellig deur die insluiting van beide elektrofiliese asook nukleifielese funksionele groepe op gekose posisies. Dit het die gebruik van ‘n hoë opbrengs Mitsunobu reaksie ingesluit. ‘n Aantal ander addisionele residueë is toe gesintetiseer en geheg aan die afgeleide adenosien om die ensiem setel te vul en sodoende die affinitieit te verhoog. Vir die tweede ensiem wat geteiken is vir inhibisie, Protein Farnesieltransferase, is indool benuttig as ‘n begin steier te dien om potensiële treffers de novo te sintetiseer. Dit is geteiken om die indool af te lei op die Nʹ en 3ʹ posisies en die kristal struktuur van een van hierdie tussengangers is gepubliseer. Verder is ‘n sintetiese weg, wat uitgeloop het op ‘n palladium gekataliseerde Suzuki koppeling, uitgevoer.
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Williams, Jarrod C. "Design and Synthesis of Superresolution Imaging Agents." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1342887517.
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Zhang, Weihe. "Design and Synthesis of Potential Anticancer Agents." Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1288896777.
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Khan, Nasim B. "Design and synthesis of potential antimicrobial agents." Thesis, Aston University, 2007. http://publications.aston.ac.uk/11064/.
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A series of pyridine-2-, pyridine-3-, pyridine-4-, pyrazine and quinoline-2-carboxamidrazone derivatives and new classes of carboxamidrazone were prepared. Over nine hundred synthesized compounds were screened for their antimycobacterial activity against M. fortutium (NCTC 10394) as a surrogate for M. tuberculosis. The new classes of amidrazones were also screened against tuberculosis H37 Rv. Fifteen tested compounds were found to provide 90-100% inhibition of mycobacterium growth of M. tuberculosis H37 Rv in the primary screen at 6.25 μg mL-1. The most active compound in the carboxamidrazone amide series had an MIC value of 0.1-2 μg mL-1 against M. fortutium. The x-ray structure of DHFR from M. tuberculosis and human DHFR were found to have differences in substrate binding site. The presence of glycerol molecule in the X-ray structure from M. tuberculosis DHFR provided opportunity to design new antifolates. The new antifolates were designed to retain the pharmocophore of pyrimethamine (2,4-diamino-5(4-chlorophenyl)-6-ethylpyrimidine), but encompassing a range of polar groups that might interact with the M. tuberculosis DHFR glycerol binding pockets. Finally, the research describes the preparation of molecularly imprinted polymers for the recognition of 2,4-diaminopyrimidine for the binding of the target. Having proven that 2,4-diaminopyrimidine interacts strongly with the model 5-(4-tert-butyl-benzylidene)-pyrimidine-2,4,6-trione, 2,4-diaminopyrimidine-imprinted polymers were prepared using a novel cyclobarbital derived functional monomer, acrylic acid 4-(2,4,6-trioxo-tetrahydro-pyrimidin-5-ylidenemethyl)phenyl ester, capable of multiple hydrogen bond formation with the 2,4-diaminopyrimidine. The recognition property of the respective polymers toward the templates and other test compounds was evaluated. The polymers showed dose dependent enhancement of fluorescence emissions. Synthesized MIPs have higher 2,4-diaminopyrimidine binding ability as compared with corresponding non-imprinting polymers.
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Sikdar, Soumick. "Design and synthesis of potential antimicrobial agents." Thesis, Aston University, 2010. http://publications.aston.ac.uk/15794/.
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Chorismate mutase is one of the essential enzymes in the shikimate pathway and is key to the survival of the organism Mycobacterium tuberculosis. The x-ray crystal structure of this enzyme from Mycobacterium tuberculosis was manipulated to prepare an initial set of in silico protein models of the active site. Known inhibitors of the enzyme were docked into the active site using the flexible ligand / flexible active site side chains approach implemented in CAChe Worksystem (Fujitsu Ltd). The resulting complexes were refined by molecular dynamics studies in explicit water using Amber 9. This yielded a further set of protein models that were used for additional rounds of ligand docking. A binding hypothesis was established for the enzyme and this was used to screen a database of commercially available drug-like compounds. From these results new potential ligands were designed that fitted appropriately into the active site and matched the functional groups and binding motifs founds therein. Some of these compounds and close analogues were then synthesized and submitted for biological evaluation. As a separate part of this thesis, analogues of very active anti-tuberculosis pyridylcarboxamidrazone were also prepared. This was carried out by the addition and the deletion of the substitutions from the lead compound thereby preparing heteroaryl carboxamidrazone derivatives and related compounds. All these compounds were initially evaluated for biological activity against various gram positive organisms and then sent to the TAACF (USA) for screening against Mycobacterium tuberculosis. Some of the new compounds proved to be at least as potent as the original lead compound but less toxic.
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Tan, Jinlong. "Design and Synthesis of Novel Antibacterial Agents." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25809.
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The latest data on antimicrobial resistance (AMR) related mortality is alarming. A conservative estimate places current global death due to AMR infections at 700,000 annually and projections anticipate that this could rise to 10 million by 2050. Over 50 major initiatives have emerged from the European Union (EU), United Kingdom (UK) and the United States of America (US) since 2007 aimed at improving surveillance, stewardship, and refreshing the drug development pipeline. The identification of priority pathogens, such as the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens has also assisted in directing global attention and efforts towards developing agents against these dangerous microbes. However, despite the FDA approval of 17 new antimicrobial agents since 2013, no novel class of Gram negative active agents has been introduced. Concerning the antibacterials in the drug development pipeline which are currently in phase 3 development or near obtaining approval (fourteen), only one (cefiderocol, a cephalosporin derivative) displays broad activity against priority Gram negative pathogens whilst seven display very specific activity against the same – none of these are new classes.
Fragment-based drug discovery (FBDD) is an efficient strategy to utilise in this research. FBDD involves virtual screening of exceptionally small ligands, termed fragments, against the crystal structure of the target protein. Fragments are known to sample chemical space more efficiently than conventional virtual screening ligand libraries. Fragment hits may have low affinity initially but demonstrate a good amount of free energy of binding per heavy atom, referred to as ligand efficiency. It is then necessary to optimise the best scoring fragments by introducing structural modifications to improve affinity and pharmacokinetic properties towards more drug-like leads.
Chapter 2 of this thesis details the design of novel Extended Spectrum β-lactamase (ESBL) inhibitors through FBDD. This begins with a discussion regarding the benefits and rationale of virtual screening, followed by details of the software and methods used by the candidate to generate drug-like small molecules against protein crystal structures of the target carbapenemase, New Delhi Metallo-β-lactamase 1 (NDM-1). Careful and rational optimisation of high scoring fragments resulted in a structurally diverse set of lead compounds with anticipated ability to restore carbapenem activity in pathogenic bacterial which express NDM-1. Furthermore, we aimed to synthesise a structural extension of lead compounds to provide a prodrug form which we hypothesised could improve effectiveness of the lead compound in Gram negative bacteria. Previously published bacteria detection and identification research by the Groundwater research group targeted an aminopeptidase widely distributed in Gram negative bacteria for differentiating between Gram negative and Gram positive species from clinical isolates. This enzyme, L-alanyl aminopeptidase, cleaved chromogenic compounds containing a terminal L-alanine amino acid residue, which released the chromophore and produced colouration of the colony. Therefore, these ‘L-alanyl precursors’ allowed for distinction between Gram positive and Gram negative bacteria in clinical isolates. We proposed that L-alanyl derivatives of the lead compounds could produce the same effect, effectively targeting the antibacterial agents towards Gram negative species, which are of greater clinical urgency. The compounds which were successfully synthesised were tested by international collaborators and, separately, by the candidate against two clinically important Gram negative pathogens. Inhibition of the target carbapenemase was determined by observed improvement of carbapenem MIC (in this case meropenem) and, therefore, required testing of the synthesised inhibitors in tandem with the carbapenem, by simultaneous broth microdilution. All synthesised compounds displayed the ability to improve meropenem MIC by at least two-fold (that is, the MIC of meropenem halved in the presence of a test inhibitor) and demonstrated no growth inhibition in the absence of meropenem at the concentrations tested. Particularly noteworthy was the performance of L-proline-based compounds, derived from fragment 1, which displayed impressive activity. The thiol-containing L-proline derivative 8 was able to improve the MIC of meropenem by sixteen-fold (i.e. from 64 µg/mL to 4 µg/mL). The L-alanyl prodrug forms of the lead compounds also, generally, demonstrated greater potency than their respective parent lead compounds. In the case of one pair, the prodrug form was seven-times more effective than the corresponding lead compound.
Chapter 3 of this thesis details the use of rational structure modification to generate improved antibacterials based on agents discovered by previous PhD candidates (Dr Liao and Dr Lin) within the research group. The target of this work was Filamenting temperature-sensitive mutant Z (FtsZ), an enzyme ubiquitous in bacteria which is critical for successful cell division and replication. FtsZ inhibitors are a validated antibacterial target, with one such inhibitor, TXA707 and its prodrug TXA709, currently in Phase 1 clinical trials. Research by Dr Liao and Dr Lin identified curcumin-based compounds 88 and 89 respectively which were successful antibacterial agents in Bacillus subtilis, a Gram positive species. The work described in Chapter 3 of this thesis aimed to introduce structural modifications to these compounds to produce less chemically reactive derivatives which retained, or, ideally, improved antibacterial activity. This resulted in the phenolic derivatives which demonstrated comparable activity against B. subtilis. However, these compounds demonstrated no significant activity against a Gram negative species of bacteria, Escherichia coli. Consequently, an L-alanyl prodrug form of the lead phenol 94 was vehemently pursued.
In summary, this thesis details the exploration of a diverse range of synthetic reactions which produced structurally diverse potential antibacterial agents. Many of these compounds exhibited encouraging antimicrobial activity, either by inhibiting a resistance-conferring enzyme (NDM-1) or by inhibiting an enzyme critical for bacterial division (FtsZ).
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Lala, Divesh. "The design and implementation of dynamic interactive agents in virtual basketball." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199434.
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La, Boissonniere François. "An approach to design autonomous agents within ModSAF." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/Mq44911.pdf.
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Jones, William Alexander. "Design and synthesis of intracellular MR contrast agents." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497879.
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Mugoyela, Veronica Kapesa. "The design and synthesis of novel trypanocidal agents." Thesis, University of Sunderland, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314809.
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Wilson, Karen. "Agents, affectivity and aesthetics in user-interface design." Thesis, Abertay University, 2007. https://rke.abertay.ac.uk/en/studentTheses/632067a9-4c26-4823-86f8-45f041a259ec.
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Human-Computer Interaction (HCI) research has suggested that there has been a general shift away from more traditional aspects of design, such as usability, and the focus is now more pleasure, or emotion, based. Jordan (2000) states that pleasurebased design is associated with more hedonic aspects, such as enjoyment, and the interaction between the user and the product. A number of studies have investigated the relationship between the user and product in relation to agents (e.g. DeAngeli, Lynch & Johnson, 2002). While it has been widely acknowledged that the use of agents enhances the user experience (e.g. Lester, Converse, Stone, Kahler & Barlow, 1997; DeAngeli et al, 2002), these agents have mainly been fully animated, which may influence perceptions as they are considered more 'human-like'. Conversely, other studies (e.g. Koda & Maes, 1996) have found that the appearance of an agent has little influence on user perceptions of attributes such as intelligence, but only if an interaction has taken place. A series of experiments were conducted in order to investigate user perceptions of agents, or more specifically the influence of aesthetics, context and interaction. Experimental work investigated rating of agents, on a variety of different attributes, in an implied financial context. It was found that there was a general positive regard for female agents, but it was unclear whether stereotypes relating to the context were driving these judgements. Additional work showed that this positive view of female agents was consistent when no context was implied. Further investigation of the role of context indicated that while context (compared to imagined context and no context) had an overall detrimental influence on perceptions of agents, there was a high general regard for both attractive agents and female agents. However, to ensure that this result did not simply arise from the choice of website (financial), additional studies investigated the extent of occupational stereotypes and whether these occupational stereotypes extended to agents. This was found to be the case. However, although the most appropriate agent for a given occupation was one that was gender-congruent with the occupation, there was still a general positive regard for attractive agents. Finally, the influence of interaction was explored, and it was found that the aesthetics, or even presence, of an agent had no effect on user perceptions. This suggests that the quality of interaction may be the most salient aspect of agent perception. These findings are discussed in relation to the literature and future studies are considered.
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Carroll, Gabriel D. (Gabriel Drew). "Approaches to mechanism design with boundedly rational agents." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/72829.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references.
This dissertation ties together three papers on mechanism design with boundedly rational agents. These papers explore theoretically whether, and to what extent, limitations on agents' ability to strategically misrepresent their preferences can help a mechanism designer achieve outcomes that she could not achieve with perfectly rational agents. The first chapter investigates whether local incentive constraints are sufficient to logically imply full incentive-compatibility, in a variety of mechanism design settings. This can be motivated by a boundedly rational model in which agents cannot contemplate all possible misrepresentations, but can consider those that are close to their true preferences. This chapter offers a unified approach that covers both continuous and discrete type spaces, showing that in many commonly studied cases, local incentive-compatibility (suitably defined) implies full incentive-compatibility. The second chapter advances the methodology of looking quantitatively at incentives for strategic behavior, motivated by the premise that agents will be truthful if the incentive to be strategic is small enough. This chapter defines a mechanism's susceptibility to manipulation as the maximum amount of expected utility any agent can ever gain from strategic misrepresntation. This measure of susceptibility is then applied to anonymous voting rules. One set of results estimates the susceptibility of specific voting rules; an important finding is that several voting systems previously identified as resistant to manipulation are actually more susceptible than simple plurality rule, by the measure proposed here. A second set of results gives asymptotic lower bounds on susceptibility for any possible voting rule, under various combinations of efficiency, regularity, and informational conditions. These results illustrate how one can quantitatively explore the tradeoffs between susceptibility and other properties of the voting rule. The third chapter carries the methodology of the second chapter to a market environment: unit-demand, private-value double auction markets. This chapter quantitatively studies the tradeoff between inefficiency and susceptibility to manipulation, among all possible mechanisms for such markets. The main result approximately locates the possibility frontier, pinning it down within a factor that is logarithmic in the size of the market.
by Gabriel D. Carroll.
Ph.D.
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Bivigou, Koumba Achille Mayelle. "Design, synthesis and characterization of novel raft agents." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/2992.
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Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005.This thesis begins with the description of the preparation of thirteen dithioesters (of the form Z- (C=S)-S-R) which were characterized via Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR) and ultraviolet spectroscopy (UV). The dithioesters were then used as reversible addition-fragmentation chain transfer (RAFT) mediating agents in the bulk polymerization of styrene, in order to observe differences in the kinetic behaviour of the polymerizations and, as a result, the efficiencies of the dithioesters in mediating the polymerizations.
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Pavlic, Theodore Paul. "Design and Analysis of Optimal Task-Processing Agents." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1281462093.
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Ayuso, A. R. "Body agents : deploying a new figure for design." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1467561/.
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The argument put forth in this thesis is based on the observation that contemporary design suffers from a ‘missing body.’ This absence stems from a Modernist aversion to the figure, which has been absorbed by contemporary design. It contributes to a diminished embodied imagination and a diminished ability to address a lived embodiment and situated subjectivity in architecture, particularly in representations and ornament. The notion of ‘body agents’— dynamic, subjective, and non-ideal figures that exist in a reciprocal state with designs— are put forward to address radically new conditions in architecture, subjectivity, and embodiment. These figures are also predicated on the importance of continuity with the past. The historical precedents that are particularly important to this thesis and inform this definition of body agents are the proto-Baroque work of Michelangelo Buonarroti, the Baroque work of Gian Lorenzo Bernini, and the more recent work of Walter Pichler which presciently evoked a technologically saturated embodiment. In these examples, figures enact the emotional and personal themes of their authors as well as broader cultural issues; they mediate between the architect and the design, but also between the inhabitant and the buildings within which they are embedded. This historical research was part of the process which also included narrative writing and the construction of hybridized images to create a cast of body agents which were deployed in design projects. The results were body agents with ‘expressive’ anatomies, comprised of reified digital meshworks that spatially and materially intertwined with their architectural contexts. My intention is to introduce body agents into contemporary design to catalyze architectural imagination and expose opportunities to interject situated and embodied intersubjectivities into design.
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Robertson, Amy Gai. "Design of rhodamine-gadolinium agents for theranostic applications." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/24653.
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The prevalence of cancer is expected to rise over the next decade, and the development of new and effective cancer treatments and diagnostic tools is urgently required. An exciting field of cancer research involves combining therapeutic and diagnostic tools into a single ‘theranostic’ platform. The role of theranostics in the personalized management of oncology patients is increasing, as is the demand for new types of theranostic agents.
This thesis investigates a series of Gd(III) complexes which utilise rhodamine-like groups to target and image the mitochondria of tumour cells. The synthesis, purification and characterisation of a series of new Gd(III)-rhodamine complexes are reported. Systematic modifications were made to both the linking groups and the rhodamine core to determine structure-activity relationships for these complexes and their fluorescent and biological properties.
Fluorescence studies were performed where absorption, emission, quantum yields, fluorescence lifetimes and pH properties were evaluated. These studies identified the role of extended delocalisation in rhodamine-like targeting groups favoring an increase in twisted intramolecular charge transfer quenching processes. These studies also showed the importance of the structural and electronic properties of the linking groups on the absorption and emission wavelengths, quantum yields and fluorescence lifetimes of the complexes in aqueous solution.
Preliminary evaluation of the biological properties of the Gd(III)-rhodamine complexes confirmed low in vitro cytotoxicity. The selectivity and uptake of the Gd(III) complexes in a healthy brain cell line (SVG p12) and glioblastoma cell line (T98G) were also determined and found to be selective for the latter at low concentrations.
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Mosley, Sylvester L. "Base-modified carbocyclic nucleosides as medicinal agents." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/27041.
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Clifton, Heather A. "Computational antiviral drug design." Muncie, Ind. : Ball State University, 2009. http://cardinalscholar.bsu.edu/645.
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Yepuri, Nageshwar Rao. "The design and synthesis of novel anti-malarial agents." Access electronically, 2004. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20050330.085201/index.html.
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Yin, Lu. "Rational Design and Development of Anti-Angiogenic Protein Agents." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/biology_diss/109.
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Inhibition of angiogenesis is an effective and low toxic therapeutic avenue for the treatment of cancer patients in addition to traditional interventions. Majority of current available angiogenesis inhibitors for cancer therapies are growth factor inhibitors and small molecule tyrosine kinase inhibitors. A number of endogenous proteins and/or proteolytic fragments of extracellular matrix proteins are shown to have the activity of inhibition of angiogenesis by directly targeting endothelial cells. Structural analyses have indicated that a common structure of anti-parallel β-sheet with a highly positively charged surface presents in many of those inhibitors. This common structural feature is critical for the maintenance of their anti-angiogenic function. With this structural information, we have designed and developed a new class of anti-angiogenic proteins by integrating the short anti-parallel β-sheet forming sequences of endogenous anti-angiogenic proteins into a stable host protein, the extracellular domain-1 of cluster of differentiation 2 molecule (CD2D1). 1D 1H NMR spectra analyses indicated that the designed anti-angiogenic protein (ref to as ProAgio) folded as a β-sheet structure similar to that of the parental protein, CD2D1. ProAgio inhibited the growth of human umbilical vein cells (HUVECs) without affecting the growth of epithelial cells, suggesting a specific effect to endothelial cells. ProAgio effectively reduced endothelial tubules formed by the co-culture of HUVECs and PC3 cells on matrix gel in vitro. The designed anti-angiogenic protein was further site-specifically PEGylated in order to improve PK/PD properties and reduce immunogenicity. Examinations with PC3 xenografts showed that both ProAgio and the PEGylated ProAgio dramatically inhibited tumor growth. Immunofluorescence staining analyses of the endothelial marker CD31 indicated dramatic decreases in tumor vessels in lengths and branching points. Histological and immunofluorescence staining analyses of tissue slices of major organs indicated that there were no pathological damages to the tissue structure or disruption of normal vessels associated with the treatment of our designed anti-angiogenic agent. Overall, our studies developed a novel anti-angiogenesis agent that may have great clinical potentials. Our concept of protein design can be extended to the development of other novel protein drugs.
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Swenberg, Thorbjörn. "Postproduction Agents : Audiovisual Design and Contemporary Constraints for Creativity." Licentiate thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-14083.
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Moving images and sounds are processed creatively after they have been recorded or computer generated. These processes consists of design activities carried out by workers that hold ‘agency’ through the crafts they exercise, because these crafts are defined by the Moving Image Industry and are employed in practically the same way regardless of company. This thesis explores what material constraints there are for such creativity in contemporary Swedish professional moving image postproduction. The central aspects concern digital material, workflow and design work as distributed activities. These aspects are coupled to production quality and efficiency at the postproduction companies where production takes place. The central concept developed in this thesis is ‘creative space’ which links quality and efficiency in moving image production to time for creativity, capacity of computer tools, user skills and constitution of digital moving image material. Creative spaces are inhabited by design agents, and might expand or shrink due to material factors. Those changes are coupled to parallel changes in quality and efficiency.Audiovisuella Medier
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AlJaidi, Bilal Ali. "The design and development of new anti-trypanosomal agents." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=14352.
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Tsoukala, Georgia. "Design and Synthesis of Glycosides as Potential Anticancer Agents." Thesis, University College London (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509312.
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Yeap, S. K. "The design of tyrosinase inhibitors as novel chemotherapeutic agents." Thesis, University of Sunderland, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378608.
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Tilbrook, Gary Stuart. "Design and synthesis of hexadentate iron (III) chelating agents." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294858.
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Chadbourne, Frances Laura. "The design and synthesis of peptide-inspired antileishmanial agents." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10635/.
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Leishmaniasis is a tropical disease caused by protozoan parasite of the genus Leishmania. The temporins are a class of antimicrobial peptides (AMPs) and have documented antibacterial and antileishmanial activity. Temporins A, B, C, F, L and 1Sa were synthesised. Fluorescein and tetramethylrhodamine, used as biological imaging agents, were attached to temporins A and B and used in biological testing to track the progress of the peptides through infected macrophage cells, and in an in vitro skin model. Temporins A and L were found to be active against both promastigotes and amastigotes, and alanine and lysine scans of these peptides were performed to attempt to identify any residues causing activity. No residues to this effect were identified, however based on this work, the largest library of antimicrobial peptides to date was synthesised and tested gainst Leishmania mexicana promastigotes and axenic amastigotes. Data obtained was subsequently used in the first reported study of computational modelling to predict the sequences of antileishmanials peptides. Based on this work, peptide sequences were predicted that may show activity as antileishmanials agents. The Ciliatamides consist of three lipopeptides named Ciliatamides A-C, of which Ciliatamide B was shown to possess high levels of antileishmanial activity. (S,S), (R,S), (S,R) and (R,R) forms of Ciliatamide B were synthesised and used in biological testing. The activity of both temporins A and B was assayed against L. mexicana promastigote and axenic amastigotes, as well as murine macrophages: Allowing for an as yet undocumented comparison between both stages of the Leishmania spp. lifecyle. Differences were noted in the activity of the promastigotes and amastigotes lifecycle stages of the parasite, with promastigotes being significantly more responsive to AMPs than the amastigotes. As all previous studies had taken place on the promastigotes lifecycle stage, this finding must be taken into consideration in planning future studies.
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Celiker, Ibrahim. "The design and synthesis of novel anti-viral agents." Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/72588/.
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Viral infections account for 25.4% of all human illnesses. Current anti-viral nucleosides are able to prevent viral replication; however, viruses evolve resistance to available treatments. Ribose nucleosides are ubiquitous; however due to the discriminatory nature of kinases, low intracellular concentrations of the active triphosphate is a significant factor in inactivity. In contrast, oxetane nucleosides have been shown to be phosphorylated by these kinases with high levels of the required active nucleotide triphosphate (NTP) resulting. Oxetane nucleosides, however, have been found to be inactivated by pyrimidine nucleoside phosphorylases (PNPs). Previous studies have illustrated that sulfur containing nucleosides are not hydrolysed by PNPs. Therefore in this programme a library of 9 novel 3,3-bis(hydroxymethyl)-thietan-2-yl nucleosides was synthesised using Vorbrüggen conditions starting from a fluorothietane precursor, over 8 steps. Cell viability studies using an XTT assay on the thymine (103% ± 4.9%), uracil (95% ± 2.3%), 5- fluorouracil (98% ± 7.5%) and 5,6-dimethyl uracil (82% ± 4.1%) derivatives showed no significant loss in cell viability at up to 100 μM concentration, suggesting they were suitable for further study in anti-viral screens. Steps towards the synthesis of a complementary library of 4,4-bis(hydroxymethyl)-thietan-2-yl nucleosides have been optimised with successful synthesis of a novel key intermediate, thietane-2-one, in a yield of 37% over 6 steps. 4’-Thiohamamelose nucleosides show promise as potential anti-viral compounds as previous studies have shown that 4’-thioribose nucleosides are stable to PNPs and have longer half-lives than ribose nucleosides. Increasing the stability of the 4’-thiohamamelose nucleosides could improve the potential for development of the anti-viral profiles of this class of compounds. Therefore the chemistry of 4’-thiohamamelose nucleosides has been explored, with an intermediate hamamelolactone being prepared in a yield of 44% over 5 steps. Small molecule nucleosides offer the greatest benefits as anti-viral compounds versus other small molecule anti-viral agents as nucleosides are able to directly halt viral replication. The sulfur containing nucleosides are potentially more stable than their ribose counterparts, leading to better pharmacological and pharmacodynamics outcomes.
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Simmons, Carl Benjamin. "Usability design of embodied conversational agents on handheld devices." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/17962.
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Embodied Conversational Agents (ECAs) potentially represent a way to deliver services to the public that would previously have require human staff. Making an ECA available online allows out-of-hours access to information and services, as well as allowing users to access the information anywhere there is an internet connection. As handheld devices grow in popularity and become the primary source of internet connection for many users, it is necessary to examine whether an ECA is appropriate for use on a handheld device, and what factors affect its usability. Over the course of four experiments this research examines how using a handheld device is different from using a PC, how an ECA should be presented on a handheld device, how using an ECA service in a public space affects the experience, and how an ECA should interact with users. It was determined that the usability of an ECA service is not affected by the device on which it is experienced, that on smaller screens or in demanding environments the ECA should be emphasised, and that text should be included in an ECA service as long as the ECA remains intermittently visible. It was also found that usability results from the laboratory can be generalised to the real world, that ECA services are appropriate for all ages and genders, that incorporating disclosure elements into an ECA service is a beneficial feature, and that while financial topics are appropriate to be discussed with an ECA, they are best kept to general rather than personal information. The following chapters present the necessary literary background to the field, before covering each experiment individually, and finally presenting detailed conclusions about the usability of ECAs on handheld devices.
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Hagemann, Justin Philip. "Design, synthesis and evaluation of novel, metal complexing agents." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1004965.
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Various chelating ligands have been designed and synthesised; these include amino-amide ligands, tetraacetic acid systems and sulfur-containing amide ligands. Difficulties in the synthesis and purification of the amino-amide ligands were largely overcome, permitting the mono acylation of ethylenediamine and the synthesis of bis(2-aminoethyl)-2-benzylpropanediamide. Novel tetraacetic acid ligands, based on the propanediamide backbone and targeted as EDTA analogues, were obtained from their methyl and benzyl esters; but the instability of the tetraacids prevented their full characterisation. Bidentate, tridentate and tetradentate sulfur-containing monoamide ligands, based on the ortho-thio acetanilide moiety, were designed to specifically chelate platinum and palladium in the presence of base metals. In their synthesis, thiocyanation was used to introduce the orth-thio group on para-substituted anilines, and further functionalisation was achieved via appropriate protection of nucleophilic sulfur moieties. A range of tetradentate, sulfur-containing diamide ligands was also synthesised by reacting substituted 2-mercaptoacetanilides with 1,2- dibromoethane. Novel ligands were characterised by spectroscopic (¹H and ¹³C NMR; IR and M S) techniques and elemental (combustion and high resolution MS) analysis. Computer modelling and ¹H NMR chemical shift data have been used to explore the conformational preferences of the sulfur-containing acetanilide ligands. The macrocyclic ligands and systems with ortho-methylthio substituents appear to exhibit the greatest degree of coplanarity of the aromatic and amide functions. Solvent extraction studies revealed that the sulfur-containing amide ligands selectively extracted palladium(II) from platinum(II), copper(II}, nickel(II} and cobalt(II}. Even though the palladium(II} was extracted from an acidic medium, certain monoamide ligands were able to complex palladium(II) through their sulfur and deprotonated amide nitrogen donors, a trithia monoamide ligand being observed to displace all the chloride ligands on palladium to form a monomeric tetracoordinate complex. The diamide ligands, however, appeared to favour extraction of palladium(II) by coordination through their sulfur donors, forming 5-membered sulfur-sulfur chelates. In basic media (pH 8-9), selected sulfur-containing monoamide and diamide ligands have been shown to complex platinum(II) and palladium(II) through their sulfur and deprotonated amide nitrogen donors. At neutral pH, a dimercapto monoamide ligand has been shown to complex platinum from cisplatin with partial expulsion of the ammine ligands, while a macrocyclic trithia monoamide ligand has been observed to complex platinum from tetrachloroplatinate with concomitant deprotonation of the amide nitrogen. Where possible, the complexes were characterised by infrared and ¹H NMR spectroscopy and have also been studied using the computer modelling soft-ware programmes, Momec® and Hyperchem®.
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Hevener, Kirk Edward. "Structure- and ligand-based design of novel antimicrobial agents." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-052-Hevener-index.htm.
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Thesis (Ph.D.)--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on February 2, 2009). Research advisor: Richard E. Lee, Ph.D. Document formatted into pages (xviii, 238 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 167-186).
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Reese, Michael. "Drug design (STAT5 modulators), development (Glyceollin I) and improvement (Esmolol Plus) /." Connect to full text in OhioLINK ETD Center, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1265033116.
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Thesis (M.S.)--University of Toledo, 2009.Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science Degree in Medicinal Chemistry." "A thesis entitled"--at head of title. Bibliography: leaves 45-48.
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Victor, Sundar K. "Negotiation Between Distributed Agents in a Concurrent Engineering System." Digital WPI, 1999. https://digitalcommons.wpi.edu/etd-theses/1083.
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"Current approaches to design are often serial and iterative in nature, leading to poor quality of design and reduced productivity. Complex artifacts are designed by groups of experts, each with his/her own area of expertise. Hence design can be modeled as a cooperative multi-agent problem-solving task, where different agents possess different expertise and evaluation criteria. New techniques for Concurrent Design, which emphasize parallel interaction among design experts involved, are needed. During this concurrent design process, disagreements may arise among the expert agents as the design is being produced. The process by which these differences are resolve to arrive at a common set of design decisions is called Negotiation. The main issues associated with the negotiation process are, whether negotiation should be centralized or distributed, the language of communication and the negotiation strategy. The goals of this thesis are to study the work done by various researchers in this field, to do a comarative analysis of their work and to design and implement an approach to handle negotiation between expert agents in an existing Concurrent Engineering Design System."
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Sun, Jian. "Computer-aided drug design for influenza A virus." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B44205156.
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Xiao, Jun. "Empirical Studies on Embodied Conversational Agents." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14080.
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A great deal of effort has been put into developing Embodied Conversational Agent (ECA) systems that provide a human-like assistant in the user interface. However, little is known whether improvements to ECA interfaces made by such efforts can ever be significant from the users point of view. I studied user experiences with ECA interfaces and evaluated the ECA style of interaction with respect to user expectation, perception, behavior and performance. I introduce a conceptual framework that offers a holistic view of the design space of ECA systems. I also have created a middleware toolkit that facilitates rapid development of application content across different speech and animation platforms. A series of user studies has been carried out to investigate the similarities and differences between human-computer interaction and human-ECA interaction and between human-ECA interaction and human-human interaction. Results from these studies provide strong evidence that people are consciously aware of the capabilities and limitations of ECAs. Traditional GUI design heuristics should be carefully followed when designing ECA interfaces. Furthermore, the results soundly suggest that designers of ECA interfaces take extra care to accommodate individual differences and preferences. Social norms that guide human-human interaction greatly affect individuals expectation and perception of ECA characteristics. The findings support the argument that drawing from both human-computer interaction and human-human interaction can be significantly advantageous to the design of both effective and affective human-ECA interaction.
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Ryan, Kimberly J. 1971. "Success measures of accelerated learning agents for e-commerce." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80616.
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Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 1999."September 1999."
Includes bibliographical references (leaves 30-31).
by Kimberly J. Ryan.
S.M.
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Ho, Mok Cheong Dean Christopher, and chris cheong@gmail com. "Hermes: Goal-Oriented Interactions for Intelligent Agents." RMIT University. Computer Science and Information Technology, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090227.102654.
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Intelligent agents are goal-oriented software entities which exhibit a number of desirable characteristics, such as flexibility and robustness, which are suitable for complex, dynamic, and failure-prone environments. However, these characteristics of individual agents are not exhibited by their interactions with each other since traditional approaches to interaction design are message-centric, and these message-centric approaches force the intelligent agents to follow prescribed message sequences in order to achieve their interactions, thus usually resulting in interactions which have limited flexibility and robustness. In this thesis an alternative to the traditional message-centric interaction design approaches is presented. In this approach, the interactions are designed based on interaction goals, and message sequences are not prescribed. Instead, message sequences emerge from the interactions as the intelligent agents attempt to achieve the interaction goals. The main contribution of this work is Hermes, a methodology for the design and implementation of goal-oriented interactions. An important motivation for Hermes is to not only allow for the design and implementation of goal-oriented interactions, but to also be pragmatic and usable by practicing software engineers. To that end, Hermes has a clear and guided design process with a notation explicitly created for the design of goal-oriented interactions. Furthermore, Hermes, which covers the design and implementation of agent interactions only, has been integrated with Prometheus, a full agent system design methodology. Guidelines for the integration are provided so that, in future, Hermes may also be integrated with other existing methodologies if desired. Hermes also provides guidelines for mapping its design artifacts to an implementation. As Hermes is goal-oriented, the implementation platform should be one that is goal-based. The guidelines help developers map the design to skeleton code. This contributes to the pragmatism of Hermes. To further ensure that Hermes is pragmatic, two prototype software support tools have been developed. The design support tool allows for the graphical design of Hermes artifacts and the implementation support tool produces skeleton code for the Jadex agent platform based on a structured textual representation of Hermes design artifacts. Although only the Jadex agent platform is currently supported, the implementation tool can be extended to accommodate other goal-based agent platforms. An empirical evaluation was carried out, and its results show that Hermes designs are significantly more flexible and robust than message-centric designs, although more time is required to design Hermes interactions. This suggests that Hermes is suitable for interactions which are complex and/or error-prone.
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Migliore, Marco. "Design, synthesis and biological evaluation of new anti-VZV agents." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54330/.
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An introduction to this work presented in this thesis involves an overview of nucleic acids and the use of nucleoside analogues in antiviral therapy. Bicyclic furano pyrimidine nucleosides (BCNA)s were discovered by the McGuigan group as potent and selective inhibitors of Varicella-Zoster Virus. A brief description of Structure Activity Relationships of this class of compounds is presented, identifying a long lipophilic chain as a specific requirements for antiviral activity. We herein report the synthesis and biological evaluation of a new series aimed to further investigate the specific requirement for biological acitivity. Two sites of BCNAs were modified on the lead compound, the side chain and the sugar moiety. A series bearing electron-donating and electron-withdrawing aryl groups was synthesised in order to investigate the role of the position of the substitutent. Then, the phosphoramidate approach was applied to the lead compound in order to broaden the spectrum of activity, which was limited only to VZV. Modifications of the sugar moiety include the inversion of all the stereo-centres of the lead compound, obtaining the L-enantiomer, and the inversion of the stereochemistry at the C-1' obtaining thus the a-derivative. Furthermore the replacement of the furano ring of the sugar with a cyclopentane was thought as a good strategy in order to increase the resistance to enzymatic cleavage. Given the poor bioavailability of the lead compound, the valyl ester was synthesised making also the hydrochloric and succinate salts to increase the chemical stability and water solubility Finally, using the intrinsic fluorescence of these derivatives, a cell study was carried out in order to investigate the distribution of the compound inside the cell.
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Snedden, Peter. "Design and synthesis of novel polymerizable and polymeric antimicrobial agents." Thesis, University of Strathclyde, 1997. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21254.
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A range of structurally diverse, novel antimicrobial agents - non-polymerizable, polymerizable and polymeric - have been synthesized and tested for antimicrobial activity against the yeast strain Saccharomyces cerevisiae EL 1 in orange and apple juice media. The aim of this work was to provide attractive candidates for use in liquid food preservatives. The acrylamido thiazolyl monomer 67 (Scheme 1) was prepared but tested as inactive. Attempts to prepare the novel thiazolylsulfanilamide monomer 69 (Scheme 2) met with failure. The non-polymerizable antimicrobial agents benzofuroxan 71 (Scheme 3), nonyl 3-amino parabens 78 (Scheme 4) and benzokathon 99 (Scheme 6) were prepared and tested for antimicrobial activity. Benzofuroxan 71 and, in particular, the parabens compound 78 displayed significant activity, whereas benzokathon 99 showed little activity. Polymerizable analogues of compounds 71, 78 and 99 would make useful targets towards the development of polymeric antimicrobial agents. Attempts to prepare the chloropropyl kathon 93a and the bromoethyl kathon 93b (Scheme 5) met with failure. In principle, the kathons 93a and 93b could be modified, through relatively straightforward chemistry, to polymerizable analogues. The triethyl, tri-n-butyl, tri-n-octyl and triphenyl polymerizable phosphonium salts 105a-d (Scheme 7) were prepared as m/p-isomeric mixtures. The pure p-isomeric analogues 111b-d were prepared also. Only the tri-n-octyl phosphonium salt l05c displayed antimicrobial activity. This result supports the general finding that cationic biocides with long alkyl chains are more active than those with shorter chains. The tri-n-butyl phosphonium salt monomer 105b was polymerized. The resulting homo-polymer 112b (Scheme 8) was found to inhibit yeast growth more than the corresponding monomer 1OSb. This result supports the general finding that polymeric biocides are more active than the corresponding low molecular weight compounds. The diiodomethyl sulfone 125 (Arnical) and the analogous monoiodo species 126 (Scheme 10) were prepared and tested for antimicrobial activity. Compounds 126 and, in particular, 125 displayed very potent activities. A polymerizable analogue of Arnical would make a useful target towards the development of polymeric antimicrobial diiodomethyl sulfones. The chemical breakdown of Amical 125, in chloroform, to molecular iodine was investigated by UV spectrophotometry. The rate of iodine production was found to be accelerated by ultraviolet light and to be decelerated by darkness. As a result of this discovery, a photochemical mechanism was proposed for the degradation. Further studies revealed that the rate of iodine production was inversely proportional to the Amical solution concentration. The monoiodo analogue 126 of Amical was also observed to break down in chloroform to produce iodine. However, iodine production resulting from the degradation of 126 was not as great compared with that of Amical. As a result, it was concluded that iodine production increases with the degree of iodonation. This conclusion was supported by UV spectrophotometric studies of the 'model' compound, iodoform (CHI3) - for solutions of identical concentration, iodine production increased in the order: 126 < 125 < CHI3. The chemical modification of Amberlyst 15 and Dowex 50-X8 sulfonic acid ion exchange resins 138 was conducted, in parallel, with the aim of producing a polymersupported diiodomethyl sulfone 142a (Scheme 12). Analytical evidence suggested that the transformation 138-142a was more successful on the Amberlyst resin. Despite this, however, only very low iodine loadings were obtained for the Amberlyst resin 142a. The Amberlyst- and Dowex-derived resin beads 138, 139, 141 and 142a were tested for antimicrobial activity in the 'dry' and 'wet' states using plate assay and liquid assay techniques respectively. Although some beads were active, and others were not, the microbiological data was too inconsistent, in general, to form any concrete conclusions regarding activity trends. The series of novel polymerizable nicotinate quaternary ammonium salts 148a-i (Scheme 13), with esters of different chain length and structure, were prepared and tested for antimicrobial activity. A selection of the analogous isonicotinate compounds 149 were also prepared and tested. It was found that an increase in ester chain length lead to an increase in activity, with the Cg, C9 and C12 nicotinate quats (l48g, 148h and 148i respectively) testing as the most active. In addition, it was found that the straight -chain compounds were more active than their branched-chain counterparts (e.g. 148e was more active than 148f). The position of the ester group on the pyridinium ring (c.f. 148 and 149 series) did not appear to significantly influence antimicrobial activity. The octyl nicotinate quat 148g was polymerized with the aim of producing a water-soluble polymeric pyridinium salt. However, the resulting homo-polymer 150 (Scheme 14) was insoluble and, as a result, was not tested for antimicrobial activity. A selection of the analogous isonicotinate compounds 149 were also prepared and tested. It was found that an increase in ester chain length lead to an increase in activity, with the Cg, C9 and C12 nicotinate quats (l48g, 148h and 148i respectively) testing as the most active. In addition, it was found that the straight -chain compounds were more active than their branched-chain counterparts (e.g. 148e was more active than 148f). The position of the ester group on the pyridinium ring (c.f. 148 and 149 series) did not appear to significantly influence antimicrobial activity. The octyl nicotinate quat 148g was polymerized with the aim of producing a water-soluble polymeric pyridinium salt. However, the resulting homo-polymer 150 (Scheme 14) was insoluble and, as a result, was not tested for antimicrobial activity. The m/p-isomeric version 151 of the quat 148g was co-polymerized, separately, with acrylamide and 2-hydroxyethyl methacrylate (Scheme 15). It was hoped that co-polymerizing 151 with a hydrophilic monomer would produce a water-soluble pyridinium salt co-polymer. However, both the co-polymers 153 and 154 were insoluble in water and, again, testing of these materials was not pursued.
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Chan, Mangtang. "Design and Modelling of Multimedia Information Systems with Semiotic Agents." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521033.
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Rodrigues, Natércia das Neves. "Ultrafast photoprotection mechanisms : expediting the molecular design of sunscreen agents." Thesis, University of Warwick, 2018. http://wrap.warwick.ac.uk/114335/.
Full textAbstract:
While ultraviolet (UV) radiation is essential for sustaining life, it can also be destructive for biological systems. In humans, for example, UV radiation initiates production of vitamin D, while also being the primary external source of skin cancer. Despite the skin's melanin providing natural protection against radiative stress, and despite the wide range of commercially available photoprotective lotions, i.e. sunscreens, skin cancer incidence has risen in recent years. The urgent need for more effective sunscreens is, therefore, obvious. However, the sunscreen industry is currently challenged with limited availability of suitable and photostable sunscreen active ingredients. The work presented in this thesis aims to address these challenges by presenting an innovative approach to sunscreen molecular design based on the unique insight provided by laser femtochemistry. The ideal sunscreen should dissipate excess energy via fast, efficient and safe relaxation mechanisms, which typically occur on ultrafast timescales. The studies presented in this thesis focus on two categories of sunscreens, the cinnamates and the anthranilates, and employ ultrafast laser spectroscopy techniques to map and understand the photoprotection mechanisms that afford these sunscreens their photoprotective capabilities. As such, this thesis constitutes a significant contribution to the field of research whose primary concern is to unveil the mechanisms of action of photoprotection in sun screen molecules: the results reported have identified key photophysical photoprotective mechanisms and raised important questions regarding the effects of a sunscreen molecule's environment on its photodynamics. Based on the insight provided by the research herein presented, a rationale for sun screen molecular design may be developed for which the molecular structure of sunscreen active ingredients can be manipulated in order to either enhance the desired energy redistribution mechanisms or hinder any relaxation pathways that may lead to harmful side photochemistry. In reaching its full potential, this innovative approach to sunscreen development has the potential to create a new generation of high-performance sunscreens to be incorporated in commercial sunscreen formulations, in an attempt to disrupt the rise in skin cancer incidence.
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Atanasijevic, Tatjana Ph D. Massachusetts Institute of Technology. "Design and Development of Calcium Sensitive Contrast Agents for fMRI." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/57682.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references.
There is a considerable interest in new technologies that allow noninvasive imaging of physiological parameters in living systems, especially in the neuroscience. Magnetic resonance imaging (MRI) is a very powerful tool for neuroimaging, because it can image the tissue noninvasively, in depth, at a good spatial (~100 pm) and temporal (~1s) resolution. In order to study neural activity at a cellular level, it would be of notable significance to combine MRI with calcium-sensitive contrast agents because of the important role of calcium as a second messenger in cellular signaling pathways. Here we describe a family of calcium sensors for MRI based on the conjugation of superparamagnetic iron oxide nanoparticles (SPIOS) to calcium sensing protein calmodulin and its target peptides. In the presence of calcium, interaction between the two protein domains drives the aggregation of SPIOs which results in up to four fold T2 changes. The calcium sensing is reversible and occurs at midpoint of roughly 1 ptM Ca , which makes these contrast agents suitable for imaging of the cytosolic calcium fluctuations in cells. We introduce two generations of these sensors: the first one based on commercial larger SPIOs, and the second one that uses small crosslinked lipid coated nanoparticles (xLCIOs) which have potential to overcome some of the limitations of the prototype sensor, such as inadequate diffusivity and relatively slow kinetic response. When combined with technologies for cellular deliveries of nanoparticles, these sensors and their derivatives may be useful for functional molecular imaging of biological signaling network in live, opaque specimens.
by Tatjana Atanasijevic.
Ph.D.
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Sae-Heng, Myra. "Design, synthesis and applications of novel multi-functional imaging agents." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11121.
Full textAbstract:
This thesis is concerned with designing and synthesising novel chemosensors for use as multi-functional imaging agents for both MRI and optical imaging towards Zn2+ sensing. The divalent zinc ion (Zn2+) is an essential biological element for living organisms and partakes in a number of biological mechanisms. As a result, any Zn2+ change in its homeostasis can lead to implications to a broad range of pathologies, both physical and neurological. This has made imaging Zn2+ ions crucial towards the elucidation of its distribution and function in cells and tissues. For this project, we have been designing novel multi - modal molecular imaging agents that will target Zn2+ in cells, and hopefully in the presence of possible competing cations. It is the synergistic combination of MRI and optical imaging that has led to the design and synthesis of a first generation of compounds. The aims have been to synthesise chemical probes based on MRI agents with the ability to sense Zn2+ levels via optical - MRI methods. In order to synthesise these probes, both a Gd3+ based MRI contrast agent and chromophore have been used for MRI and fluorescence visualization respectively. A Zn2+ sensor has also been attached, which upon binding should cause a molecular or electronic change which would be detected primarily via the chromophore. Three probes were designed and their synthesis towards them explained throughout the thesis. The first section of the thesis describes the preparation of a quinoline-based DO3A derivative for eventual complexation to a Gd3+ centre. The synthesis and purification methods are discussed, followed by some preliminary studies of the probe‟s behaviour towards Zn2+ ions. The second part of the thesis explains the various building blocks required to subsequently synthesise the final two probes, by discussing various synthetic approaches, in particular efforts to derivatise new fluorophores and Zn2+ sensing groups. The final part of the thesis discusses approaches towards a 1,7 - bi-substituted DOTA - based Gd3+ complex and a DOTA - based tetraamide Gd3+ complex. The successful probes that were developed were fully characterised and have undergone preliminary MRI and biological tests. They have been found to be MRI active with the ability to enter and be non - toxic towards cells with an ability to sense Zn2+ ions selectively. Fluorescence tests have also exhibited a change in fluorescence by the probe when perturbed by Zn2+ ions.
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Pierrot, David. "Etude de nouveaux agents antipaludiques innovants : design, synthèse et bioactivité." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4365.
Full textAbstract:
La spéciophylline (ou Uncarine D) est une molécule extraite d’une plante africaine endémique Mitragyna inermis qui présente une activité antipaludique contre la souche chloroquinorésistante W2 de Plasmodium falciparum, un des parasites responsables du paludisme. Son mode d’action est encore inconnu et des quantités plus importantes de produit naturel sont nécessaires pour poursuivre les études d’activité biologiques. Ces quantités ne peuvent être fournies par extraction des feuilles de Mitragyna inermis. Les objectifs de ce travail ont été d’établir une méthodologie de synthèse énantiosélective du motif spiranique de la spéciophylline pour en réaliser la synthèse totale, d’étudier l’activité antiplasmodiale de sous-structures afin de déterminer le pharmacophore de la spéciophylline et de fournir des quantités suffisantes de spéciophylline pour continuer l’étude du mode d’action de cette moléculeSpeciophyllin (or Uncarine D) is a natural product extracted from the endemic African plant Mitragyna inermis. It is active against Plasmodium falciparum’s chloroquine-resistant strain W2 which is one of the malaria responsible parasites. Speciophyllin’s action pathway remains unknown and more important amounts that cannot be provided by plant extraction are required to go on with the biologic activity studies. The aims of this work were to develop an enantioselective synthetic methodology to access speciophyllin’s spiranic core to be able to achieve its total synthesis. Through substructures synthesis and antiplasmodial activity evaluation we could study speciophyllin’s pharmacophore